Abstracts of Current Literature

I VASCULAR

Duplex Ultrasonography in the Diag­nosis of Celiac and Mesenteric Ar­tery Occlusive Disease. Jon C. Bower­sox, Robert M. Zwolak, Daniel B. Walsh,et al. J Vase Burg 1991; 14:780-788.(R.M.Z., Section ofVascular Surgery,Dartmouth Hitchcock Medical Center,One Medical Center Dr, Lebanon, NH03756)

• Duplex ultrasound (US) criteria for thediagnosis of celiac and superior mesentericartery occlusive disease have not been welldefined. The authors performed a blindedretrospective comparison of mesenteric du­plex data with arteriography in 24 consecu­tive patients who underwent both studies.Arteriography revealed that eight superiormesenteric arteries were normal; five wereminimally stenotic; eight had stenoses of50% or more and three were occluded. Nineceliac arteries were normal or minimally ste­notic; 12 had stenoses of 50% or more, andthree were occluded. Duplex scans were ob­tained after an overnight fast. In normalsuperior mesenteric arteries, peak systolicvelocity (PSV) was 134 em/sec ± 18and end-diastolic velocity (EDV) was 24em/sec ± 4. Superior mesenteric artery PSVin patients with minimal or no stenosis(171 ± 22 em/sec) was less than PSV in pa­tients with severe (> 50%) stenosis (299 cm/sec ± 40, P = .006), and less than PSV inpatients with patent superior mesentericarteries who underwent revascularization(336 em/sec ± 86, P = .017). Similarly, EDVwas elevated in superior mesenteric arterieswith severe stenosis (78 em/sec ± 11,P = .001) and in patients who underwentrevascularization (111 em/sec ± 19,P < .001) compared to those with less than50% stenosis (30 em/sec ± 6, P = .00l). AnEDV greater than 45 em/sec was the bestindicator of severe stenosis (sensitivity, 1.0;specificity, 0.92). Peak systolic velocitygreater than 300 em/sec was less sensitive(0.63), but highly specific (1.0) for severesuperior mesenteric artery stenosis. Tripha­sic superior mesenteric artery Doppler wave­forms were present only in normal or mini­mally stenotic superior mesenteric arteries,making their absence sensitive (1.0), but notspecific (0.46) for severe superior mesentericartery stenosis. Normal superior mesentericarteries had biphasic low resistance wave-

434

forms in the presence of replaced right he­patic arteries. Monophasic superior mesen­teric arteries were found occasionally in lessstenotic arteries in the presence of severeceliac stenosis or occlusion. Celiac arteriesthat were normal or minimally stenotic hadlow resistance biphasic waveforms withPSV = 152 ± 40 and EDV = 40 + 7,whereas stenotic celiacs had monophasicsignals, variable velocities, and were oftendifficult to insonate adequately. Overall,eight patients underwent mesenteric revas­cularization, and each had an abnormal out­come on preoperative duplex examination.Mesenteric duplex US is an effective diag­nostic tool and should be considered early inthe evaluation of patients with suspectedchronic mesenteric artery occlusive disease.AUTHORS' ABSTRACT

Comparison of the HydrophilicGuidewire in Double- and Single­Wall Entry Needles: Potential Haz­ards. Kathleen Reagan, Alan H. Matsu­moto, George P. Teitelbaum. CathetCardiovase Diagn 1991; 24:205-208.(KR., Department of Radiology, George­town University Hospital, 3800 ReservoirRd, NW, Washington, DC 20007)

• The potential hazard of using a newplastic-coated guide wire directly throughboth beveled, single-wall and nonbeveled,double-wall arterial puncture needles wasassessed in an in vitro model. Guide-wirewithdrawal directly through both types ofneedles resulted in either scraping and/orshearing of the plastic coating of the guidewire, leading to potential embolic debris.This problem was more significant when theguide wire was withdrawn through the bev­eled needle, in comparison with the nonbev­eled type. Extreme caution should be usedwhen using plastic-coated guide wires di­rectly through metallic arterial entry nee­dles.AUTHORS' ABSTRACT

Mortality over a Period of 10 Yearsin Patients with Peripheral ArterialDisease. Michael H. Criqui, Robert D.Langer, Arnost Fronek, et al. N Engl JMed 1992; 326:381-386. (M.H.C., Depart­ment of Community and Family Medi­cine, Division of Epidemiology-0607, Uni­versity of California, San Diego, School ofMedicine, La Jolla, CA 92093-0607)

• Background. Previous investigatorshave observed a doubling of the mortalityrate among patients with intermittent clau-

dication, and the authors have reported afourfold increase in the overall mortalityrate among subjects with large-vessel pe­ripheral arterial disease, as diagnosed bynoninvasive testing. In this study, the au­thors investigated the association of large­vessel peripheral arterial disease with ratesof mortality from all cardiovascular diseasesand from coronary heart disease. Methods.The authors examined 565 men and women(average age, 66 years) for the presence oflarge-vessel peripheral arterial disease bymeans of two noninvasive techniques-mea­surement of segmental blood pressure anddetermination of flow velocity with Dopplerultrasound. The authors identified 67 sub­jects with the disease (11.9%), whom theyfollowed up prospectively for 10 years. Re­sults. Twenty-one of the 34 men (61.8%) and11 of the 33 women (33.3%) with large-ves­sel peripheral arterial disease died duringfollow-up, as compared with 31 ofthe 183men (16.9%) and 26 of the 225 women(11.6%) without evidence of peripheral arte­rial disease. Mter multivariate adjustmentfor age, sex, and other risk factors for cardio­vascular disease, the relative risk of dyingamong subjects with large-vessel peripheralarterial disease as compared with those withno evidence of such disease was 3.1 (95%confidence interval, 1.9 to 4.9) for deathsfrom all causes, 5.9 (95% confidence inter­val, 3.0 to 11.4) for all deaths from cardio­vascular disease, and 6.6 (95% confidenceinterval, 2.9 to 14.9) for deaths from coro­nary heart disease. The relative risk of deathfrom causes other than cardiovascular dis­ease was not significantly increased amongthe subjects with large-vessel peripheral ar­terial disease. Mter the exclusion of subjectswho had a history of cardiovascular diseaseat base line, the relative risks among thosewith large-vessel peripheral arterial diseaseremained significantly elevated. Additionalanalyses revealed a I5-fold increase in ratesof mortality due to cardiovascular diseaseand coronary heart disease among subjectswith large-vessel peripheral arterial diseasethat was both severe and symptomatic.Conclusions. Patients with large-vessel pe­ripheral arterial disease have a high risk ofdeath from cardiovascular causes.AUTHORS' ABSTRACT

Color-Flow Duplex Scanning for theSurveillance and Diagnosis of AcuteDeep Venous Thrombosis. Mark A.Mattos, Gregg L. Londrey, Darr W. Leutz,et al. J Vasc Surg 1992; 15:366-376. (D.S.Sumner, Southern Illinois UniversitySchool of Medicine, Department of Sur­gery, PO Box 19230, Springfield, IL62794-9230)

• Compared with conventional duplex im­aging, color-flow scanning facilitates theidentification of veins (especially below theknee), decreases the need to assess Dopplerflow patterns and venous compressibility,and allows veins to be surveyed longitudi­nally. These advantages translate into a lessdemanding and time-consuming examina­tion. This study was designed to determinethe accuracy of color-flow scanning for de­tecting acute deep venous thrombosis in pa­tients in whom the diagnosis is clinicallysuspected and in asymptomatic patients athigh risk for developing postoperative deepvenous thrombosis. The diagnostic groupincluded 77 limbs of75 patients, and thesurveillance group included 190 limbs of99patients undergoing total hip or knee re­placement. All patients were prospectivelyexamined with color-flow scanning and phle­bography. In the diagnostic group, the inci­dence ofthrombi in below-knee veins (47%)was approximately equal to that in above­knee veins (43%); but in the surveillancegroup, the incidence of thrombi in below­knee veins (41%) far exceeded that in veinsabove the knee (3%). Nonocclusive clots andclots isolated to a single venous segmentwere more common in the surveillancegroup. In symptomatic patients, color-flowscanning was 100% sensitive and 98% spe­cific above the knee and 94% sensitive and75% specific below the knee. In the surveil­lance group, color-flow scanning was signifi­cantly (P < .001) less sensitive (55%) fordetecting thrombi, 93% of which were con­fined to the tibioperoneal veins. Negativepredictive values were 100% and 88% for thediagnostic and surveillance limbs, respec­tively. Positive predictive values were 80%for the diagnostic limbs and 89% for the sur­veillance limbs. Color-flow scanning effec­tively excludes above-knee deep venousthrombosis in symptomatic patients andasymptomatic high-risk patients and pre­dicts the presence of above-knee thrombi inpatients in the diagnostic group with reason­able accuracy (97%). The authors concludethat color-flow scanning is as accurate as

conventional duplex imaging and, because ofits advantages, is the noninvasive method ofchoice for evaluating patients with sus­pected deep venous thrombosis. Its role inthe surveillance of patients at high risk re­mains to be determined and awaits furtherclinical evaluation.AUTHORS' ABSTRACT

Suprarenal Greenfield Filter Place­ment to Prevent Pulmonary Embo­lus in Patients with Vena Caval Tu­mor Thrombi. David W. Brenner, CathyJ. Brenner, Janet Scott, et aI. J Urol1991; 147:19-23. (From the Departmentsof Urology, Surgery, and Physiology,Eastern Virginia Medical School, Norfolk,Virginia)

• The presence of tumor thrombus sec­ondary to inferior vena caval extension fromrenal carcinoma carries the threat of pulmo­nary tumor embolus. In theory, safe prophy­laxis could be accomplished by placement ofa Greenfield filter in the suprarenal venacava, which has been accomplished withoutcomplication. The authors treated six pa­tients with renal cell carcinoma and exten­sive tumor thrombus of the vena cava withsuprarenal filter placement as an adjunct tothrombectomy and nephrectomy. Clinically,all six patients have done well. However, theover-all rate of vena caval thrombosis or oc­clusion associated with infrarenal filterplacement is 3% to 5%. To investigate thepotential risk to renal function if a vena ca­val occlusion occurred above a solitary kid­ney shortly after unilateral nephrectomy,suprarenal inferior vena caval ligations wereperformed after unilateral nephrectomy in10 dogs. A total of six dogs suffered persis­tent loss of renal function, and three ofthese six died of uremia. Offour dogs whounderwent suprarenal inferior vena cavalligation, only one (25%) had persistent com­promise of renal function. A total of twodogs underwent unilateral nephrectomyonly without compromise of normal renalfunction. The authors conclude that the riskof total vena caval occlusion after suprarenalGreenfield filter placement is small. How­ever, should it occur in the setting of recentnephrectomy there is potential for signifi­cant renal morbidity. In selected patientsthis risk may be offset by the potential bene­fits that the filter offers in terms of protec­tion against tumor and/or bland pulmonaryembolus. Further clinical experience will beneeded to strengthen and clarify the indica­tions and benefits of preoperative or intraop­erative filter placement as reported.AUTHORS' ABSTRACT

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Volume 3 Number 2

Outcome of Noncardiac Operationsin Patients with Severe CoronaryArtery Disease Successfully TreatedPreoperatively with Coronary An­gioplasty. Kenneth C. Huber, Mark A.Evans, John F. Bresnahan, et aI. MayoClin Proc 1992; 67:15-21. (D.R. Holmes,Division of Cardiovascular Diseases,Mayo Clinic, Rochester, MN, 55905)

• The risk of perioperative myocardial in­farction and death was evaluated in 50patients (mean age, 68 years) with severecoronary artery disease who underwent anoncardiac operation after revascularizationhad been achieved by means of successfulpercutaneous transluminal coronary angio­plasty. Before angioplasty, all patients werethought to be at high risk for perioperativecomplications on the basis of assessment ofclinical variables and findings on specializeddiagnostic tests. Of the 50 patients, 31 hadCanadian Heart Association class III or IVangina or unstable angina. All patients whounderwent functional testing had positiveresults. At catheterization, 38 patients(76%) had multivessel disease. The 50 pa­tients underwent 54 noncardiac operationsat a median of9 days after angioplasty. Theoverall frequency of perioperative myocar­dial infarction was 5.6%, and the mortalitywas 1.9%. Two nonfatal non-Q-wave infarc­tions and one fatal Q-wave infarction oc­curred. In patients who have undergone suc­cessful angioplasty for severe coronaryartery disease, the risk of major cardiac com­plications associated with a noncardiac sur­gical procedure is low.AUTHORS' ABSTRACT

Percutaneous Implantation of a NewIntracoronary Stent in Pigs. Frits W.Bar, Jan van Oppen, Hans de Swart, et al.Am HeartJ 1991; 122:1532-1541.(F.W.B., Department of Cardiology, Aca­demic Hospital of Maastricht, PO Box1918, 6201 BX Maastricht, The Nether­lands)

• Sixty-two self-expanding parallel wirestainless steel stents were implanted in nor­mal coronary arteries of 31 young pigs byusing a newly developed delivery system. In57 of62 procedures, the percutaneous coro­nary implant of the stent was successful;five stents were released in side branches.Implants remained in place for a few hoursto 6 months. In spite of correct sizing, twostents migrated out of the coronary arteries.Seven pigs died prematurely; in six of themdeath might be stent-related. Although noanticoagulant and antiplatelet aggregation

436 • Journal of Vascular and Interventional Radiology

May 1992

drugs were administered during the fol­low-up period, at autopsy thrombi were ob­served in only seven arteries (nonobstructivein four of seven arteries). All arteries exceptfor three were patent; these three vesselsoccluded probably due to oversizing of thestent. Complete neointimal coverage wasfound within 3 weeks. Important hyperpla­sia was not seen. It was concluded that coro­nary implantation of this stent usually waseasy. Obstructive thrombus formation wasrather uncommon despite the absence ofchronic anticoagulant and antiplatelet ag­gregation therapy. Hyperplasia was rare.AUTHORS' ABSTRACT

Short and Long Term Results afterIntracoronary Stenting in HumanCoronary Arteries: Monocentre Ex­perience with the Balloon-Expand­able Palmaz-Schatz Stent. MichaelHaude, Raimund Erbel, Uwe Straub, etal. Br Heart J 1991; 66:337-345. (M.H.,2nd Medical Clinic, Johannes GutenbergUniversity, Langenbeckstrasse 1, D-65Mainz, Germany)

• Objective-Intracoronary stenting wasdesigned to overcome acute complicationsafter percutaneous transluminal coronaryangioplasty and to achieve a reduced rate ofrestenosis, both of which are major limita­tions of this well accepted method for treat­ing coronary heart disease. This report de­scribes the experience at one centre with theimplantation of balloon-expandable Palmaz­Schatz stents and focuses on device-relatedcomplications and the short and long termangiographic outcome. Design-A retrospec­tive data analysis. Patients-Stenting wasattempted in 50 patients. Restenosis afteran initially successful angioplasty procedure,inadequate postangioplasty results, saphe­nous coronary bypass stenoses, and bail-outsituations were regarded as indications.Main outcome measures and results-In 49of 50 patients 61 stents (one to four per pa­tient) were implanted. Delivery problemsoccurred in three patients and were success­fully overcome in two patients. Bail-out situ­ations were successfully managed in 16patients. Complications included acutethrombus formation within the stent imme­diately after implantation in one patient,which was successfully treated with throm­bolysis. One patient was sent for bypass sur­gery the day after implantation; anotherdied 10 days after implantation for unknownreasons. Subacute stent thrombosis oc­curred in seven patients 5-9 days after im­plantation and was successfully treated withthrombolysis or balloon angioplasty in five

patients. Bleeding complications occurred innine patients, five of whom required bloodtransfusions. Angiography showed longterm vessel patency after 4-6 months in 31(76%) of the 41 patients who were followedup, restenosis in six (14%), and reocclusionin four (10%). Late restenosis or reocclusionwas found in five (15%) of 33 patients with asingle stent in contrast to five (63%) ofeightpatients with multiple stents. Conclusions­Balloon-expandable intracoronary stentingis a feasible method for treating the acutecomplications of balloon angioplasty. It re­duced the rate of restenosis for single stentimplantation. Subacute thrombotic eventsmust be regarded as previously unknownand serious complications.AUTHORS' ABSTRACT

High Speed Rotational CoronaryAtherectomy for Patients with Dif­fuse Coronary Artery Disease. Paul S.Teirstein, David C. Warth, Najmul Haq,et al. JAm Col! Cardiol1991; 1694-1701.(P.S.T., Scripps Clinic and ResearchFoundation, 10666 N Torrey Pines Rd, LaJolla, CA 92037)

• High speed rotational coronary atherec­tomy was undertaken using the Rotablatorin 42 patients who were suboptimal candi­dates for balloon angioplasty. Most patients(71%) had diffuse coronary artery disease,defined as a stenosis of more than 1 cm inlength. Previous restenosis after balloon an­gioplasty was present in 21% and 10% hadan ostial lesion. Adjunctive balloon angio­plasty was not used to reduce residual steno­sis after atherectomy. The procedure wassuccessful in 76% of patients. Proceduralsuccess was achieved in 92% of patients witha lesion of 1 cm or less in length, but in only70% of patients with a lesion longer than 1cm (P < .01). One patient sustained abruptclosure of the target vessel, resulting inemergency bypass surgery and death. Smallnon-Q wave myocardial infarction occurredin eight patients (19%) and was associatedwith a longer lesion. The mean peak creatinekinase value in patients with non-Q wavemyocardial infarction was 683 U fL. Tran­sient regional wall motion abnormalitieswere noted on the postatherectomy left ven­tricular angiogram in four of the eight pa­tients with non-Q wave myocardial infarc­tion. Follow-up angiography (at a meaninterval of 6.2 months ± 2) was performedin 91% of patients and revealed restenosis(> 50% narrowing) in 59%. The restenosisrate was 22% for short lesions ( :s; 1 cm) and75% forlong lesions (> 1 cm) (P < .05). Inthis study, the results of high speed rota-

tional coronary atherectomy were stronglyinfluenced by lesion length. Although shortlesions (:s; 1 cm) were treated effectively,longer lesions (> 1 cm) were associated withdecreased procedural success, increased pro­cedural complications, and a higher resteno­sis rate.AUTHORS' ABSTRACT

A Comparison of Angioplasty withMedical Therapy in the Treatment ofSingle-Vessel Coronary Artery Dis­ease. Alfred F. Parisi, Edward D. Fol­land, Pamela Hartigan, on behalf of theVeterans Affairs ACME Investigators. NEngl J Med 1992; 326:10-16. (A.F.P.,Miriam Hospital, 164 Summit Ave, Provi­dence, RI 02906)

• Background. Despite the widespread useof percutaneous transluminal coronary an­gioplasty (PTCA), only a few prospectivetrials have assessed its efficacy. The authorscompared the effects of PTCA with those ofmedical therapy on angina and exercise tol­erance in patients with stable single-vesselcoronary artery disease. Methods. Patientswith 70%-90% stenosis of one epicardial cor­onary artery and with exercise-induced myo­cardial ischemia were randomly assignedeither to undergo PTCA or to receive medi­cal therapy and were evaluated monthly.The patients assigned to PTCA were urgedto have repeat angioplasty if their symptomssuggested restenosis. After 6 months, all thepatients had repeat exercise testing and cor­onary angiography. Results. A total of 107patients were randomly assigned to medicaltherapy and 105 to PTCA. PTCA was clini­cally successful in 80 of the 100 patients whoactually had the procedure, with an initialreduction in mean percent stenosis from76% to 36%. Two patients in the PTCAgroup required emergency coronary-arterybypass surgery. By 6 months after the proce­dure, 16 patients had had repeat PTCA.Myocardial infarction occurred in five pa­tients assigned to PTCA and in three pa­tients assigned to medical therapy. At 6months 64% of the patients in the PTCAgroup (61 of 96) were free of angina, as com­pared with 46% of the medically treated pa­tients (47 of 102; P < .01). The patients inthe PTCA group were able to increase theirtotal duration of exercise more than themedical patients (2.1 vs 0.5 minutes,P < .0001) and were able to exercise longerwithout angina on treadmill testing(P < .01). Conclusions. For patients withsingle-vessel coronary artery disease, PTCAoffers earlier and more complete relief ofangina than medical therapy and is associ-

ated with better performance on the exercisetest. However, PTCA initially costs morethan medical treatment and is associatedwith a higher frequency of complications.AUTHORS' ABSTRACT

Utility of Duplex Ultrasound in theDiagnosis of Asymptomatic Cathe­ter-induced Subclavian Vein Throm­bosis. William D. Haire, Thomas G.Lynch, Robert P. Lieberman, et aI. J Ul­trasound Med 1991; 10:493-496.(W.D.H., Department oflnternal Medi­cine, University of Nebraska Medical Cen­ter, 600 S 42nd St, Omaha, NE 68198­3330)

• Asymptomatic thrombosis of the subcla­vian vein is common after placement of ind­welling catheters. The sequelae of thesethrombi are not known. Investigation ishampered by the requirement for venogra­phy for diagnosis; consequently, a noninva­sive method of diagnosis would be welcomein this context. The authors have studiedprospectively 32 subclavian catheters to de­termine the usefulness of duplex ultrasound(US) in diagnosing asymptomatic thrombo­sis. Sixteen arm venograms were normaland all gave normal duplex scans. No false­positive scans were obtained. Eleven veno­grams demonstrated nonocclusive muralthrombi. Only three of these were seen withduplex US. Five totally occlusive thrombiwere seen on venography, of which only twowere detected with duplex sonography. Thethree thrombi not found with duplex USwere short proximal venous occlusions. Theinsensitivity of this technique to asymptom­atic subclavian thrombi limits its usefulnessas a screening tool.AUTHORS'ABSTRACT

The Comparative Evaluation ofThree-dimensional Magnetic Reso­nance for Carotid Artery Disease.Donald K. Wilkerson, Irwin Keller, Re­uben Mezrich, et aI. J Vasc Surg 1991;14:803-811. (M.A. Zatina, Department ofSurgery UMDNJ-Robert Wood JohnsonMedical School, One Robert Wood Place,New Brunswick, NJ 08903-0019)

• Conventional angiography is the currentstandard for the evaluation of carotid arterydisease. The excellent resolution of this in­vasive study is offset by the potential forcontrast material-related, embolic, andpuncture site complications. Three-dimen­sional magnetic resonance (MR) angiogra­phy may offer a noninvasive diagnosticalternative. The authors examined this pos­sibility by performing both conventional an-

giography and three-dimensional MR an­giography in 13 patients. Cervical duplexscans were also obtained in these patients.Contiguous transverse cervical MR imageswere acquired in a 1.5-T magnet with use ofa posterior neck coil and a gradient-echopulse sequence. These "raw" data weretransferred to a real-time workstation wherethree-dimensional cervical arterial imageswere reformatted, magnified, and examinedfrom multiple angles. Total study time frompatient positioning to image generation wasapproximately 30 minutes. In all patients, atthree-dimensional MR angiography the com­mon, external, and internal carotid arteriesand distal vertebral arteries were easily dis­cernable and correctly identified as patent,stenotic, or occluded. Three-dimensional MRangiography was not accurate in detectingcarotid ulcers. The degree of internal carotidartery stenosis measured from the three­dimensional MR angiography studies corre­lated well with the internal carotid arterystenosis measured with conventional angiog­raphy (r = 0.866, r2 = 75.1%, P S; .0001).This recent technologic advance representssignificant progress toward achieving thegoal of completely noninvasive vascular as­sessment in this patient population.AUTHORS' ABSTRACT

Brachial Plexus Injury: Associationwith Subclavian and Axillary Vascu­1ar Trauma. Steven F. Johnson, StevenB. Johnson, William E. Strodel, et aI. JTrauma 1991; 31:1546-1550. (S.B.J.,C-222, Chandler Medical Center, 800Rose St, Lexington, KY 40536-0084)

• Proximal upper extremity (subclavianand axillary) vascular injury (SAVD and bra­chial plexus injury (BPD occur uncommonly.However, BPI may be associated with SAVIand frequently is an important determinantoflong-term disability. The medical recordsof patients with traumatic SAVI, BPI, orboth over a 5-year period were reviewed. Atotal of 31 patients were identified. Thegroup was predominantly male (28 men, 3women), with a mean age of 30.5 years ± 1.8(range, 15-63 years). Blunt trauma ac­counted for 43.5% of SAVI cases and 77.8%of BPI cases. Thirteen patients (41.9%) sus­tained SAVI alone (group D, 10 patients(32.2%) had combined SAVI and BPI (groupII), and eight patients (25.9%) had BPI alone(group III). SAVI occurred in 10 of 18 pa­tients (55.6%) with a BPI. BPI occurred in10 of23 patients (43.5%) with a SAVI. Pa­tients with SAVI from blunt trauma weresignificantly more likely to have an associ­ated complete BPI than patients with pene-

Abstracts • 437

Volume 3 Number 2

trating trauma. All patients with a completeBPI (six patients) had an associated SAVIregardless of mechanism of injury. Only onepatient with a partial BPI from blunttrauma had an associated SAVI. The InjurySeverity Score was significantly higher forpatients in group II. An average of 2.8 and3.3 associated injuries were observed in pa­tients with SAVI (groups I and II) versuspatients without SAVI (group lID, respec­tively. No patient who had a complete BPIshowed an improvement in neurologic sta­tus during a mean follow-up of 7.2 months.No late vascular sequelae occurred in groupIII patients. Two patients, both with pene­trating injuries, died (mortality 6.5%) as adirect result of the injury. In conclusion, thisstudy demonstrates that (a) BPls are com­monly associated with SAVls; (b) BPI maybe a harbinger of occult vascular injury andis an indication for upper extremity angiog­raphy; and (c) assuming SAVls are success­fully repaired, BPls are the primary deter­minant oflong-term disability.AUTHORS' ABSTRACT

Evidence Implicating NonmuscleMyosin in Restenosis: Use of in SituHybridization to Analyze HumanVascular Lesions Obtained by Direc­tional Atherectomy. Guy Leclerc, Jef­frey M. Isner, Marianne Kearney, et aI.Circulation 1992; 85:543-553. (J.M. Is­ner, St Elizabeth's Hospital, 736 Cam­bridge St, Boston, MA 02135)

• Background. Identification of genes thatare specifically activated in restenosis le­sions after percutaneous transluminal an­gioplasty represents a necessary step towardmolecular manipulation designed to inhibitcellular proliferation responsible for suchlesions. Whereas quiescent smooth musclecells (contractile phenotype) preferentiallyexpress smooth muscle myosin, proliferatingsmooth muscle cells (synthetic phenotype)have been shown to preferentially expressnonmuscle myosin in vitro. Accordingly, theexpression of a recently cloned isoform ofhuman nonmuscle myosin heavy chain(MHC-BJ was analyzed in fresh human rest­enotic lesions. Methods and Results. A totalof 10 lesions, including four restenosis(three superficial femoral arterial lesionsand one saphenous vein bypass lesion) andsix primary (four superficial femoral arteriallesions and two coronary arterial lesions)obtained percutaneously by directionalatherectomy, were processed for examinationby in situ hybridization. In total, 150 tissuesections of restenotic lesions (66 sections),primary lesions (78 sections), and normal

438 • Journal of Vascular and Interventional Radiology

May 1992

internal mammary artery (six sections) werehybridized with the nonmuscle MHC-Bprobe. Restenotic lesions showed intensehybridization to the nonmuscle MHC-BcRNA probe, as demonstrated by a cluster­ing of more than 20 grains per cell nucleusin 80% of the cells examined within a high­power field (x250); in contrast, an equiva­lent degree of hybridization was observed inonly 7% of cells within primary lesions(P < .00l). Results ofimmunocytochemis­try using monoclonal antibody to smoothmuscle actin indicated that cells demon­strating strong hybridization were smoothmuscle in origin. Conclusions. These find­ings demonstrate that (a) human vasculartissue obtained by percutaneous directionalatherectomy constitutes appropriate biopsymaterial for gene expression studies at themRNA level, and (b) nonmuscle MHC-BmRNA is present in greater abundanceamong restenotic versus primary vascularstenoses. These observations thus provide arational basis to explore restenotic lesionson a larger scale to identify genes that areactivated in these lesions and establish po­tential targets for future gene therapy.AUTHORS' ABSTRACT

Complications and Validity of Pul­monary Angiography in Acute Pul­monary Embolism. Paul D. Stein,Christos Athanasoulis, Abass Alavi, et al.Circulation 1992; 85:462-468. (P.D.S.,Henry Ford Heart and Vascular Institute,2799 W Grand Blvd, Detroit, MI 48202)

• Background. The Prospective Investiga­tion of Pulmonary Embolism Diagnosis(PIOPED) addressed the value of ventilationperfusion scans in acute pulmonary embo­lism (PE). The present study evaluates therisks and diagnostic validity of pulmonaryangiography in 1,111 patients who under­went angiography in PIOPED. Methods andResults. Complications were death in five(0.5%), major nonfatal complications in nine(1%), and less significant or minor in 60(5%). More fatal or major nonfatal complica­tions occurred in patients from the medicalintensive care unit than elsewhere: five of122 (4%) versus nine of989 (1%) (P < .02).Pulmonary artery pressure, volume of con­trast material, and presence of PE did notsignificantly affect the frequency of compli­cations. Renal dysfunction, either major (re­quiring dialysis) or less severe, occurred in13 of 1,111 (1%). Patients who developedrenal dysfunction after angiography wereolder than those who did not have renal dys-

function: 74 ± 13 years versus 57 ± 17 years(P < .00l). Angiograms were nondiagnosticin 35 of 1,111 (3%), and studies were incom­plete in 12 of 1,111 (1%), usually because ofa complication. Surveillance after negativeangiograms showed PE in four of675(0.6%). Angiograms, interpreted on the basisof consensus readings, resulted in an un­challenged diagnosis in 96%. Conclusions.The risks of pulmonary angiography weresufficiently low to justify it as a diagnostictool in the appropriate clinical setting. Clini­cal judgment is probably the most importantconsideration in the assessment of risk.AUTHORS' ABSTRACT

Diagnosis of Acute Pulmonary Em­bolism in the Elderly. Paul D. Stein,Alexander Gottschalk, Herbert A. Saltz­man, et al. JAm Call Cardiall991; 18:1452-1457. (P.D.S., Henry Ford Heartand Vascular Institute, 2799 W GrandBlvd, Detroit, MI 48202)

• The diagnostic features of acute pulmo­nary embolism among 72 patients 70 yearsof age or older were evaluated and comparedwith characteristics of pulmonary embolismamong 144 patients 40-69 years and 44 pa­tients younger than 40 years old. Syndromescharacterized by either (a) pleuritic pain orhemoptysis, (b) isolated dyspnea, or (e) cir­culatory collapse were observed with compa­rable frequency among patients 70 years andolder and younger patients. One of thesepresenting syndromes occurred in 64 (89%)of the 72 patients who were 70 years orolder. Those who did not show these syn­dromes were identified on the basis of unex­pected radiographic abnormalities, whichmay have been accompanied by tachypnea ora history of thrombophlebitis. Among the 72patients 70 years of age or older with pulmo­nary embolism, dyspnea or tachypnea (respi­rations z 20/min) occurred in 66 (92%),dyspnea or tachypnea or pleuritic pain in 68(94%), and dyspnea or tachypnea or radio­graphic evidence of atelectasis or a paren­chymal abnormality in 72 (100%). Complica­tions of angiography were evaluated amongpatients with and without pulmonary embo­lism. Major complications of pulmonary an­giography among patients 70 years or older(two [1%] of200) were not more frequentthan among younger patients (six [1.1%] of562) (P = NS). However, renal failure (ma­jor or minor) was more frequent in patients70 years or older than in younger patients(six [3%] of 200 versus four [0.7%] of 562)(P < .05). The nonspecific manifestations ofpulmonary embolism, even among patients

70 years of age or older, are usually present.When necessary, pulmonary angiographycan be performed with no greater overallfrequency of complications in elderly pa­tients, although renal failure after angiogra­phy is a problem in the elderly.AUTHORS' ABSTRACT

Angiographically Placed Balloonsfor Arterial Control: A Descriptionof a Technique. Thomas M. Scalea, Sal­vatore J. A. Sclafani. J Trauma 1991; 31:1671-1677. (T.M.S., Department of Sur­gery, Box 40, 450 Clarkson Ave,Brooklyn, NY 11203)

• Obtaining proximal and distal control isessential in the repair of arterial injuries.Occasionally, the location ofthe injurymakes this difficult, risks excessive bloodloss, or requires wide exposure to obtaincontrol. Recently, the authors have usedpercutaneously placed balloons as an aid tovascular control in 11 patients who had arte­rial injuries identified angiographically. Theballoon is placed under fluoroscopic guid­ance and is then deflated. The balloon is re­inflated intraoperatively at the time vascularcontrol is needed. Five balloons were placedfor inflow control in patients with very prox­imal subclavian artery injuries. All werethen able to undergo successful repairthrough a limited supraclavicular incisionwithout sternotomy or thoracotomy. Twowere placed in the internal carotid artery toobtain distal control in injuries located atthe base of the skull. Both injuries werethen repaired without problems. Two pa­tients had balloons placed for external iliacartery injuries located at the inguinalliga­ment, one for proximal and one for distalcontrol. Both injuries were then repairedthrough a limited incision. Two additionalpatients who had arterial injuries identifiedbegan to bleed massively while in the an­giography suite. Balloons were placed proxi­mally to control bleeding during transportand dissection. There were no complicationsfrom balloon placement. All balloons func­tioned well, greatly limited blood loss, andallowed for repair through a limited incision.This is a technique that can be utilized inselected cases of angiographically identifiedarterial injuries in which operative exposureis likely to be difficult, cause significantblood loss, or require an extensive incisionand dissection.AUTHORS' ABSTRACT

Therapeutic Alternatives for Sub­acute Peripheral Arterial Occlusion:Comparison by Outcome, Length ofStay, and Hospital Charges. John E.Janosik, Michael A. Bettmann, Alan F.Kaul, et al. Invest Radiol1991; 26:921­925. (MAB., Department of Radiology,University Hospital, 88 E Newton St,Boston, MA 02118)

• Thrombolytic therapy with streptoki­nase or urokinase has been shown to be aviable alternative to surgical thrombectomyin patients with subacute peripheral arterialocclusion. Urokinase is associated withhigher success and lower complication ratesthan streptokinase, but the cost ofuroki­nase is at least seven times higher. To ad­dress questions of utility and effectiveness inthe treatment of subacute peripheral arte­rial occlusions, the authors designed a retro­spective study of patients treated either bymeans of surgical thrombectomy (n = 70),thrombolysis with streptokinase (n = 19), orthrombolysis with urokinase (n = 22). Out­come of therapy, length of hospital stay, andtotal hospital charges in the three groupswere examined. Treatment successes in thethree groups, defined as complete clearing ofthe occluded segment with patency main­tained for 60 days, were 76% for thrombec­tomy, 32% for streptokinase, and 64% forurokinase. Total duration of hospitalizationwas 21.1, 21.3, and 11.5 days (P < .05), re­spectively. Mean charges for thrombolyticagents were $690 for streptokinase and$6,429 for urokinase. Mean total hospitalcharges, however, were $25,978 for strep­tokinase, $22,203 for urokinase, and$25,336 for thrombectomy (P = NS). Thehigher cost of urokinase, then, accounted forthe similar total charges, despite the short­ened length of stay. These results suggestthat urokinase is cost-effective compared tostreptokinase for subacute peripheral arte­rial occlusion. Compared with thrombec­tomy, thrombolysis with urokinase has amarginally lower patency rate at 60 days,but a significantly shorter hospital stay.AUTHORS' ABSTRACT

An Evaluation of New Methods of Ex­pressing Aortic Aneurysm Size: Rela­tionship to Rupture. Kenneth Ouriel,Richard M. Green, Carlos Donayre, et al.J Vase Burg 1992; 15:12-20. (KO., De­partment of Surgery, University of Roch­ester, 601 Elmwood Ave, Rochester, NY14642)

• The diameters of aortic aneurysms werestandardized to measures of patient size andnormal aortic size in an effort to define in-

dexes that might be more predictive of aneu­rysm rupture than raw aneurysm diameteralone. Normal aortic diameters were mea­sured in 100 patients undergoing abdominalcomputed tomography (CT) for other rea­sons, and an average infrarenal aortic diam­eter of 2.10 cm ± 0.05 was observed. Normalaortic diameter was dependent on both ageand sex, ranging from 1.71 cm ± 0.06 inwomen younger than 40 years to 2.85 cm ±0.04 in men older than age 70 years. Overall,11 (5.1%) of the ruptures occurred in aneu­rysms less than 5 cm in diameter, and four(1.9%) occurred in aneurysms less than 4.0cm in diameter. When the CT scans of 100patients undergoing elective aneurysm re­section were compared with those of 36 pa­tients with ruptured aneurysms, no thresh­old diameter value accurately discriminatedbetween the two groups. However, standard­ization of the aneurysm diameter to thetransverse diameter of the third lumbar ver­tebral body as an index of patient body sizeproduced an accurate predictor of rupturewhen a threshold ratio of 1.0 was used. Noaneurysm ruptured below this ratio, but29% of elective aneurysms were smallerthan the vertebral body diameter. Receiveroperating characteristic curve analysis con­firmed the superiority of the aneurysm tovertebral body diameter ratio as a discrimi­nator of ruptured aneurysms. It appearsthat aneurysm diameter alone is not suffi­ciently predictive of rupture to be used asthe sole indication for elective resection.AUTHORS' ABSTRACT

The Selective Management of SmallAbdominal Aortic Aneurysms: TheKingston Study. Peter M. Brown, RuthPattenden, John R. Gutelius. J Vase Burg1992; 15:21-27. (P.M.B., Department ofSurgery, Kingston General Hospital,Kingston, Ont, Canada R7L 2X2)

• The management of small abdominalaortic aneurysms less than 5.0 cm maximumdiameter remains controversial particularlyin patients who are medically fit. All patientsreferred with abdominal aortic aneurysmsless than 5.0 cm maximum diameter wereprospectively followed regardless of theirfitness for operation. Two hundred sixty­eight patients had been entered into thestudy by December 31, 1988, and monitoreduntil December 31, 1990, by at least two an­eurysm sizings by means ofultrasonogra­phy, computed tomography, or both. Themean follow-up was 42 months. Operationswere performed on 114 patients (if theywere fit for operation) when the aneurysmreached 5.0 cm, expanded more than 0.5 cm

Abstracts • 439

Volume 3 Number 2

in a 6-month period, or when the patienthad significant occlusive disease requiringrepair. In this group the mean annual in­crease in diameter was 0.9 em. One hundredfifty-four patients were monitored withoutoperation for a mean period of 42 months.One rupture occurred in this group. The av­erage annual increase in diameter in thegroup not undergoing operation was 0.24cm. This study supports a policy of observa­tion for abdominal aortic aneurysms lessthan 5.0 cm in maximum diameter.AUTHORS' ABSTRACT

A Blinded Comparison of Angiogra­phy, Angioscopy, and Duplex Scan­ning in the Intraoperative Evalua­tion of in Situ Saphenous VeinBypass Grafts. Jeffrey J. Gilbertson,Daniel B. Walsh, Robert M. Zwolak, et al.J Vase Burg 1992; 15:121-129. (D.B.W.,Section ofVascular Surgery, Dartmouth­Hitchcock Medical Center, Hanover, NH03756)

• Angiography, angioscopy, and duplexscanning have each been advocated for in­traoperative assessment of in situ saphe­nous vein grafts. The authors comparedthese three modalities during operation in aprospective, blinded study during the con­struction of20 femoral-infragenicular insitu saphenous vein grafts. Each modalitywas used and interpreted by a surgeonblinded to the results of the other studies.Abnormalities requiring intervention weredefined as (a) patent vein side branches, (b)residual valve cusps, and (e) anastomoticstenoses greater than 30%. Criteria, specificto the modality, corresponding to eachcategory were prospectively defined. Four­teen residual valve cusps, 49 patent veinbranches, and six anastomotic stenoses weresuggested by at least one modality. Nine re­sidual valve cusps, 32 patent vein branches,and no anastomotic stenoses were actuallyfound (and corrected) at direct inspection.Sensitivity of detecting patent side branchesfor angiography, duplex scanning, and an­gioscopy was 44%, 12%, and 66%, respec­tively. Both angiography and angioscopywere significantly more sensitive than du­plex scanning for detection of unligated sidebranches (P < .01). Sensitivity of detectingresidual valve cusps was 22% (angiography),11% (duplex scanning), and 100% (angios­copy). Angioscopy was significantly moresensitive than either duplex scanning or an­giography in detection of residual valvecusps (P < .01). Since no anastomotic ste­noses were confirmed, the false-positiverates for stenosis detection were 20% for

440 • Journal of Vascular and Interventional Radiology

May 1992

angiography, 10% for duplex scanning, and0% for angioscopy. Time requirement was17-20 minutes and did not differ among thethree modalities. No stenosis or arterio­venous fistula has been detected in any graftby postoperative duplex surveillance (mean,lO-month follow-up). Angiography and an­gioscopy were superior to duplex scanningfor detecting patent vein branches. Angiog­raphy or duplex scanning alone would havemissed more than 75% of residual valvecusps. These results suggest that angioscopyis the preferred method for intraoperative insitu vein graft evaluation.AUTHORS' ABSTRACT

Reversed Vein Graft Stenosis: EarlyDiagnosis and Management. Henry D.Berkowitz, Andrew D. Fox, David H.Deaton. J Vasc Surg 1992; 15:130-142.(H.D.B., Presbyterian Medical Center,Suite 101, Medical Arts Bldg, 39th andMarket St, Philadelphia, PA 19104)

• Conscientious surveillance of intrain­guinal bypass grafts is mandatory to detectvein graft stenoses, which, if uncorrected,can lead to graft occlusion. It is now widelyaccepted that noninvasive vascular labora­tory studies are the best way to detect theselesions. However, controversy still existsover treatment, specifically whether balloonangioplasty is an acceptable substitute forsurgery (patch angioplasty or short jumpgrafts) in the treatment of these lesions. Theauthors have always favored balloon angio­plastyas primary treatment and have sum­marized their experience with treating 72stenotic reversed femoropopliteal and femo­rotibial vein grafts, which represent 12% of521 bypass grafts performed at their institu­tion. Prosthetic and in situ grafts are specifi­cally excluded from this report, as well asoccluded grafts, found to have stenotic le­sions after lytic therapy. The most commonstenotic lesion occurred within 4 cm of theproximal anastomosis (29 of 72 = 40%). Theother sites were near the distal anastomosis(seven of72 = 10%), and in the middle ofthe graft (15 of 72 = 12%). Eighty-one per­cent of the lesions (58 of 72) were treatedinitially by balloon angioplasty with a 31%recurrence. Twenty-nine percent of the 14grafts treated surgically by means of veinpatch angioplasty or short jump grafts expe­rienced recurrence. Overall 61% of the ste­notic grafts (44 of 72) were treated by meansof balloon angioplasty alone. The 5-year life­table assisted primary patency after correc­tion of the stenotic lesion was 61%. The pa-

tency of the grafts from the time of initialbypass surgery, however, was 80%. Locationof the stenosis within the graft was a majordeterminant of patency. Lesions in the prox­imal graft, proximal anastomosis, and distalgraft taken as a group had significantly bet­ter patency than the midgraft and distalanastomotic lesions (5-year patency, 65% vs48%; P < .001 log rank test). The authorscontinue to recommend balloon angioplastyas primary therapy for vein graft stenosisexcept for those occurring in the midgraftand distal anastomosis. Fortunately, thisgroup accounts for only 36% oflesions seenwith reversed veins. Recurrent stenosis afterballoon angioplasty should be repaired surgi­cally.AUTHORS' ABSTRACT

Arterial Emboli of Venous Origin.Steven Katz, George Andros, Roy Kohl, etal. Surg Gynecol Obstet 1992; 174:17-21.(S.K., 10 Congress St, Suite 504, Pasa­dena, CA 91105)

• In a small but significant group ofpa­tients with documented systemic emboli, asource is never determined. It is in thisgroup of patients that an arterial embolus ofvenous origin should be considered. Duringthe past 20 years, the authors identified fourpatients who fulfilled the diagnostic criteriafor an arterial embolus of venous origin. Ineach, the diagnosis was made during life. Inaddition, the authors reviewed the 40 addi­tional patient reports in the literature thatappeared to meet the criteria for the diagno­sis of venous origin arterial emboli. Nonin­vasive methods were useful in determiningthe presence of thrombus in the venous sys­tem, and right to left shunting across an in­tracardiac defect. The authors conclude thattreatment with heparin is the mainstay oftherapy, and that caval interruption shouldbe used only on a selective basis.AUTHORS'ABSTRACT

Antithrombotic Effects of Combin­ing Activated Protein C and Uroki­nase in Nonhuman Primates. AndrasGruber, Laurence A. Harker, Stephen R.Hanson, et al. Circulation 1991; 84:2454­2462. (J.H. Griffin, Department of Molec­ular and Experimental Medicine, BCR 5,Scripps Clinic and Research Foundation,10666 N Torrey Pines Rd, La Jolla, CA92037)

• Background. The authors have deter­mined in vivo the relative antithromboticefficacy and hemostatic safety of combining

low-dose activated protein C (APC) andurokinase (urinary plasminogen activator,u-PA), two natural proteins that regulatethrombogenesis. Methods and Results. Tomodel acute thrombotic responses of nativeblood under conditions of arterial flow,thrombogenic segments of Dacron vasculargraft (VG) were incorporated into chronicexteriorized femoral arteriovenous (AV) ac­cess shunts in baboons. Thrombus forma­tion on VG was determined by measuring (a)the deposition of autologous 111In plateletsusing real-time scintillation camera imaging,(b) the accumulation of 1251 fibrin, (c) seg­ment patency by Doppler flow analysis, and(d) blood tests for thrombosis, includingplasma concentrations of platelet factor 4,(3-thromboglobulin, fibrinopeptide A (FPA),and D-dimer. Treatments consisting of low­dose and intermediate-dose APC (0.07 or0.25 mg/kg' h), u-PA (25,000 or 50,000 lU/kg· h), or the combination were adminis­tered for 1 hour by continuous intravenousinfusion. In untreated controls, platelets andfibrin accumulated rapidly, reaching plateauvalues at 1 hour of 15.1 ± 3.8 x 109 plateletsand 7.8 ± 2.2 mg fibrin. Although the low­dose APC or u-PA alone did not decreaseeither platelet or fibrin deposition signifi­cantly, this combination moderately reducedboth platelet and fibrin accumulation(7.3 ± 2.6 x 109 platelets, P < .05; 3.9 ±0.6 mg fibrin, P < .05). Furthermore, in­termediate-dose APC or u-PA reducedthrombus formation by half when adminis­tered alone (P < .001 for both platelet andfibrin deposition), and the combinationmarkedly interrupted the accumulation ofplatelets (3.0 ± 1.0 x 109 platelets,P < .001) and fibrin (1.3 ± 0.6 mg fibrin,P < .001). During active treatments, all VGsegments remained patent. Hemostatic plugforming capability, as measured by templatebleeding times, remained normal during allexperiments (P > .05). The T50 clearancetime for APC activity was not affected by theconcurrent administration ofu-PA. u-PAalone increased the plasma levels of D-dimer,FPA, and, interestingly, APC, implying thatduring pharmacological activation of thefibrinolytic system, thrombin activity wasreleased, and the protein C pathway was ac­tivated. Conclusions. A combination of in­termediate-dose APC and u-PA produce sub­stantial and efficient antithrombotic effectswithout impairing hemostatic function.AUTHORS' ABSTRACT

Three-dimensional Reconstructionof Human Coronary and PeripheralArteries from Images Recorded Dur­ing Two-dimensional IntravascularUltrasound Examination. KennethRosenfield, Douglas W. Losordo, K Ra­maswamy, et al. Circulation 1991; 84:1938-1956. (J.M. Isner, St Elizabeth'sHospital, 736 Cambridge St, Boston, MA02135)

• Background. Intravascular ultrasound(US) provides high-resolution images of vas­cular lumen, plaque, and subjacent struc­tures in the vessel wall; current instrumen­tation, however, limits the operator toviewing a single, tomographic, two-dimen­sional image at anyone time. Comparativeanalysis of serial two-dimensional imagesrequires repeated review of the video play­back recorded during the two-dimensionalexamination, followed by a "mind's eye"type of imagined reconstruction. Methodsand Results. Computer-based, automatedthree-dimensional reconstruction was usedto generate a tangible format with which toassess and compare a "stacked" series oftwo-dimensional images. Three-dimensionalrepresentations were prepared from sequen­tial images obtained during intravascularUS examination in 52 patients, 50 of whomwere studied before and/or after percutane­ous revascularization. Conventional two­dimensional US images were acquired bymeans of a systematic, timed pullback of theUS catheter through the respective vascularsegments. Images were then assembled inautomated fashion to create a three-dimen­sional depiction of the vessel lumen andwall. Computer-enhanced three-dimensionalreconstructions were generated in both sag­ittal and cylindrical formats. The sagittalformat resulted in a longitudinal profile sim­ilar to that obtained during angiographicexamination; in contrast to angiography,however, the sagittal reconstruction offered3600 oflimitless orthogonal views of theplaque and arterial wall as well as the vascu­lar lumen. The cylindrical format yielded acomposite view of a given vascular segment,and a hemisected version of the cylindricalreconstruction enabled en face inspection ofthe reconstructed luminal surface. Sagittalreconstructions facilitated analysis of dissec­tions and plaque fractures resulting frompercutaneous revascularization, and thehemisected cylindrical reconstruction en­hanced analysis of endovascular prostheses.Conclusions. This preliminary experiencedemonstrates that computer-based three­dimensional reconstruction may furtheraugment the use of intravascular US in as-

sessing vascular pathology and guiding in­terventional therapy.AUTHORS' ABSTRACT

Long-term Results after Percutane­ous Transluminal Angioplasty ofAtherosclerotic Renal Artery Steno­sis: The Importance of Intensive Fol­low-up. Henrik Weibull, David Bergqvist,Kjell Jonsson, et al. Eur J Vase Surg1991; 5:291-301. (From the Departmentsof Surgery, Radiology and Endocrinology,Lund University, Malmo General Hospi­tal, Malmo, Sweden)

• The aim of this study was to investigatethe long-term results of percutaneous trans­luminal angioplasty of atherosclerotic renalartery stenosis (PTRA) in patients with ren­ovascular hypertension with or without im­pending renal insufficiency who were fol­lowed up intensively with aggressivereintervention. Diagnostic work-up wasbased on angiography, pressure gradient,and renal venous renin measurement. Pa­tients were scheduled for regular follow-upafter the PTRA, and a deterioration in bloodpressure or renal function was an indicationfor re-evaluation and repeat intervention ifnecessary. Sixty-five patients had 71 renalartery stenoses where PTRA was attempted.It was technically successful in 59 stenosesand two occlusions and failed in ten (14%).At the end offollow-up (median, 56 months[2-99]), the primary patency rate was 55%,27 had restenosed and four were occluded,all but two within 12 months. Seventeenwere treated with a further PTRA and eightwith surgical reconstruction. At the end offollow-up the secondary patency after allinterventions was 90%. One patient died 1month after PTRA, and at the end of fol­low-up 21 patients (32%) had died, most ofthem (80%) from cardiovascular disease.Multivariate analyses showed a significantlyreduced survival rate in patients with multi­locular atherosclerosis, renal insufficiency,contralateral renal artery stenosis andischaemic heart disease. At the end offol­low-up 90% of the patients were cured orimproved with regard to blood pressure. Inpatients with impending renal insufficiency,renal function was improved in 50% and un­changed in 39%. With this strategy 55% ofthe patients needed only one treatment withPTRA, 25% needed a repeat PTRA and 20%had to be operated on. PTRA can be recom­mended as initial treatment of atheroscle­rotic renal artery stenosis provided intensivefollow-up and aggressive reintervention areperformed when indicated.AUTHORS' ABSTRACT

Abstracts • 441

Volume 3 Number 2

Failure of Peripheral Arterial Bal­loon Angioplasty: Does Platelet De­position Playa Role? K R. Poskitt, A.Harwood, D. J. A. Scott, et al. Eur J VaseSurg 1991; 5:541-547. (KR.P., Consult­ant Vascular Surgeon, Cheltenham Gen­eral Hospital, Sandford Rd, Cheltenham,Glos, GL53 7AN UK)

• The pathophysiological response to pe­ripheral percutaneous transluminal balloonangioplasty in 20 patients was investigatedusing indium-Ill-labelled platelets. Plateletdeposition was quantified by measuring thedegree of radioactivity uptake at angioplastyand control sites using a computer linkedsystem and expressing the uptake as a ratioof angioplasty/control. Following plateletlabelling, scans were obtained before angio­plasty and at 1, 24, and 48 hours after angio­plasty. To assess patency of the angioplasty,ankle brachial Doppler pressure indices wereobtained and supported by repeat angio­grams if doubt of patency existed. All pa­tients were followed-up at 1 week, 1 month,and 6 months to correlate the degree of earlyplatelet uptake with failure. The mean ±sem platelet radioactivity ratio at the angio­plasty site increased from 1.1 ± 0.1 prior tothe procedure to a peak of 2.1 ± 0.3 at 1hour (P < .01),1.6 ± 0.2 at 24 hours (P <.05), and 1.7 ± 0.3 at 48 hours (P < .05).Angioplasties that failed within 6 monthstended to have a higher maximum earlyplatelet uptake (3.1 ± 0.6) compared to suc­cessful angioplasties (1.9 ± 0.3), but the dif­ference was not significant in the numbersstudied. This study provides a suitablemodel to assess the role of platelet accumu­lation in angioplasty failure and the influ­ence of various antiplatelet regimes.AUTHORS' ABSTRACT

Femoro-popliteal Artery OcclusionsTreated by Percutaneous Translumi­nal Angioplasty and EnclosedThrombolysis: Results in 55 Patients.K H. Tl/lnnesen, P. Holstein, E.Andersen. Eur J Vase Surg 1991; 5:429­434. (KH.T., Department of ClinicalPhysiology/Nuclear Medicine, BispebjergHospital, DK-2400 Copenhagen NY, Den­mark)

• Removal of fibrin from the site of anewly dilated femoropopliteal occlusion maybe an attractive way of preventing rethrom­bosis. A double balloon catheter with a dilat­ing tip balloon and an occlusive balloon 10,15 or 20 cm proximately were introducedpercutaneously. Following successful dilata­tion of femoropopliteal occlusions, the bal­loons were inflated on both sides of the le-

442 • Journal of Vascular and Interventional Radiology

May 1992

sion. The dilated segment was then isolatedfrom the circulation. Through a side portbetween the balloons, 5 mg of tissue-typeplasminogen activator and 1,000 IU ofhepa­rin were instilled within the segment for 30minutes. The authors report the results of53 technically successful dilatations of femo­ropopliteal occlusions followed by enclosedthrombolysis. A 100% patency at 3 monthswas noted in 33 patients having one to threerun-off arteries, and the 1 year patency was90%. In 20 patients, with no infrapoplitealrun-off artery, four rethromboses occurredwithin 24 h, and the 1 year patency was62%. This difference is significant. (Log ranktest, x2 = 4.73, P < .05). Enclosed throm­bolysis prevents early reocclusion followingpercutaneous transluminal angioplasty offemoropopliteal occlusions provided that atleast one infrapopliteal artery is patent.AUTHORS'ABSTRACT

Growth Factors in Pathogenesis ofCoronary Arterial Restenosis. BojanCercek, Behrooz Sharifi, Peter Barath, etal. Am J Cardiol1991; 68:24C-33C. (J.S.Forrester, Division of Cardiology, Cedars­Sinai Medical Center, 8700 Beverly Blvd,Los Angeles, CA 90048)

• Restenosis occurs in 25% to 55% ofpa­tients within 6 months of successful angio­plasty. The major histologic component ofthe restenotic lesion is intimal hyperplasia,which is almost certainly driven by growthfactors. After vascular injury, smooth mus­cle cells proliferate, reaching a maximumrate at day 2. Smooth muscle cell prolifera­tion diminishes as the vessel surface is re­endothelialized at about day 7, and by week4 the smooth muscle cell mitotic rate re­turns to baseline of less than 1% per day.The events of the histologic evolution of ar­terial injury can be used to create a hypo­thetical paradigm for the role of growth fac­tors in restenosis. Restenosis might logicallybe prevented by an inhibitory interventionat any of the various steps in the healingprocess.AUTHORs'ABSTRACT

Older Age and Elevated Blood Pres­sure are Risk Factors for Intracere­bral Hemorrhage after Thromboly­sis. Jeffrey L. Anderson, LabrosKaragounis, Ann Allen, et al. Am J Car­dio11991; 68:166-170. (J.L.A., LDS Hos­pital, Eighth Ave and CSt, Salt LakeCity, UT 84143)

• Intracerebral hemorrhage is an impor­tant concern after thrombolytic therapy foracute myocardial infarction, but risk factors

are controversial. Accordingly, the authorsassessed risk factors in 107 treated patientsof whom four had intracerebral hemorrhage.Intracerebral hemorrhage occurred at amean of 25 hours (range 3.5 to 48) aftertherapy and was fatal in two patients. Sig­nificant differences were found between pa­tients with and without intracerebral hem­orrhage for age (77 ± 7 vs 62 ± 11 years,P ,;; .01), and initial (161 ± 23 vs 135 ± 23mm Hg, P ,;; .03) and maximal (171 ± 30 vs146 ± 20, P ,;; .02) systolic blood pressures.Initial and maximal diastolic blood pres­sures also tended to be higher (101 ± 25 vs86 ± 16,P,;; .07; 104 ± 24vs90 ± 13,P ,;; .06). Differences did not achieve signifi­cance for comparisons of gender, height,weight, site of infarction, time to therapy,specific thrombolytic agent used, concomi­tant therapy, interventions and partialthromboplastin time. It is concluded thatage (~ 70 years) and elevated blood pressure(~ 150/95 mm Hg) are important risk fac­tors for intracerebral hemorrhage. The over­all balance of benefit and risk ofthromboly­sis should continue to be assessed by largemortality trials.AUTHORS' ABSTRACT

Intracoronary Ultrasound Evalua­tion of Interventional Technologies.Charles J. Davidson, Khalid H. Sheikh,Katherine B. Kisslo, et al. Am J Cardiol1991; 68:1305-1309. (C.J.D., Box 31195,Duke University Medical Center,Durham, NC 27710)

• The feasibility and applicability of intra­vascular ultrasound (IVUS) of the coronaryarteries were evaluated in 65 patients un­dergoing 70 coronary interventional proce­dures. Morphologic and quantitative analy­ses were performed with a mechanicallyrotated IVUS catheter (4.8 F, 20 MHz) andwith orthogonal view cineangiography. Asemiautomated edge-detection algorithmwas used for cineangiographic quantifica­tion. Coronary interventions included 45percutaneous transluminal coronary angio­plasties, nine excimer lasers, 11 directionalcoronary atherectomies, three rotationalatherectomies, and two stent placements.Most lesions consisted of a mixture of plaquecomposition (hard, n = 30; soft, n = 64).Other unique morphologic data by IVUSwere plaque topography (eccentric, n = 34;concentric, n = 36) and vessel dissection(IVUS [n = 29] vs angiography [n = 14],P < .05). Postprocedure minimal lumen di­ameter and cross-sectional area measured byIVUS were larger and poorly correlated withangiography (r = 0.28, standard error of the

estimate = 0.52 mm; r = 0.08, standard er­ror ofthe estimate = 1.0 cm2, respectively).IVUS is more sensitive than angiographywhen assessing postintervention lesion char­acteristics including vessel dissection andplaque morphology. Catheter-based ultra­sound appears to be a useful adjunct to con­trast angiography when evaluating andcomparing the therapeutic impact of conven­tional percutaneous transluminal coronaryangioplasty with new technologies.AUTHORs'ABSTRACT

CARDIAC

Balloon Dilatation of the ArterialDuct in Congenital Heart Disease.Kevin P. Walsh, Narayanswami Sreeram,Roger Franks, et al. Lancet 1992; 339:331-332. (KP. Walsh, Heart Clinic, RoyalLiverpool Children's Hospital, Alder Hey,Liverpool, L12 2AP, UK)

• The systemic circulation of newborn in­fants with congenital left-heart obstructionis supplied from the right ventricle via apatent arterial duct between the pulmonaryartery and descending aorta. The duct closesduring the first few days of life, but infusionof prostaglandin E2 can prevent closure insome cases. The authors describe four new­born infants (aged 3-8 days) with intracta­ble heart failure due to severe obstruction ofthe left heart in the presence of a closingarterial duct. Infusion of prostaglandin E2

did not improve their clinical condition. Car­diac catheterisation and balloon dilatation oftheir arterial ducts resulted in a dramaticimprovement in the babies' clinical condi­tion; during subsequent surgical repair ofthe infants' hearts, the arterial ducts werefound to be widely patent. Balloon dilatationgives immediate and sustained wide patencyof the arterial duct in infants who do notrespond adequately to prostaglandin E2•

AUTHORS' ABSTRACT

HEPATOBILIARY

Ultrasonographic Findings and Man­agement of Intrahepatic BiliaryTract Abnormalities after Portoen­terostomy. Tsukasa Nakama, TakatoshiKitamura, Akira Matsui, et al. J PediatrSurg 1991; 32-36. (T.N., Department ofPediatric Surgery, Jichi Medical School,Minamikawachi-machi Kawachi-gun,Tochigi-ken 329-04, Japan)

• Ultrasonographic (US) examination wasmade in 24 children who had undergone aportoenterostomy to correct extrahepaticbiliary atresia. Abnormalities were observedin six patients. These were the result of on­going inflammatory reactions because allhad been suffering from cholangitis aftersurgery, and the size of the biliary tractstructure changed in accordance with theoccurrence and subsidence of the cholangi­tis. US examination showed dilation of theintrahepatic bile duct in one patient and cys­tic lesions in five patients. Treatment in­cluded percutaneous transhepatic bile drain­age for dilated bile ducts, alcohol injectionsfor intrahepatic cysts, and reoperation forcysts in the porta hepatis. Treatment wasnot required for cysts in controllable cholan­gitis. The results of these approaches wereexcellent, indicating that they were of ben­efit in treating intrahepatic abnormalitiesoccurring after portoenterostomy.AUTHORS' ABSTRACT

The Natural History of Carcinoma ofthe Bile Duct in Patients Less ThanForty-Five Years of Age. Kimberly D.Saunders, Ronald K. Tompkins, Joe A.Cates, et al. Surg Gynecol Obstet 1992;174:1-6. (J.J. Roslyn, Division of GeneralSurgery, UCLA School of Medicine, 10833Le Conte Ave, Rm 72-215 CHS, Los Ange­les, CA 90024)

• Traditionally regarded as a disease ofthe elderly, the natural history of carcinomaof the bile duct in young patients has notbeen well defined. Of 186 patients (meanage, 62 years) treated at UCLA (1954-1988)for carcinoma of the bile duct, 26 were lessthan 45 years old. Younger patients hadsymptoms for an average of 4.5 months ±0.8 prior to diagnosis, as compared with 2.3months ± 0.2 for patients more than 45years old (p < .03). Ofthe younger patients,96% were managed surgically with eitherresection, surgical palliative bypass, or lapa­rotomy and tube drainage. Among theyounger patients who underwent resections,

92% were alive at 1 year, as compared with60% of patients who underwent palliativebypass procedures. Two patients who under­went tumor resections survived 4 years orlonger. The authors conclude that carci­noma of the bile duct is not limited to theelderly and occurs in a significant number ofyoung patients. In the younger population,carcinoma of the bile duct is characterizedby delays in diagnosis. Early suspicion andaggressive management of young patientswith obstructive jaundice are essential toensure the best possible outcome for pa­tients with this disease.AUTHORS' ABSTRACT

Percutaneous Removal of RetainedIntrahepatic Stones with a Pre­shaped Angulated Catheter: Reviewof 96 Patients. Joon Koo Han, ByungIhn Choi, Jae Hyung Park, et al. Br JRadial 1992; 65:9-13. (J.K.H., Depart­ment of Radiology, Seoul National Uni­versity Hospital, 28 Yongon-dongChongno-gu, Seoul 110-744, Korea)

• Intrahepatic biliary stone disease isprevalent in East Asia, and there is a highfrequency of retained intrahepatic stonesafter surgical treatment. Percutaneous re­moval of retained intrahepatic stones with apre-shaped angulated catheter and a Dor­mier basket was attempted in a group of 96patients who had a T tube. Seventy-six hadmultiple intrahepatic stones, confined to onehepatic lobe in 52 patients. Stones were ex­clusively intrahepatic in 68 cases. Biliarystrictures were present in 92 cases (95.8%).A combination of techniques was used in­cluding pre-shaped angulated catheters,irrigation suction, balloon dilatation ofstrictures, crushing of large stones and ex­tracorporeal shockwave lithotripsy. Re­tained stones were completely removed in 48cases, and incompletely removed in 22 cases.The overall success rate was 72.9%. Therewere only minor complications. No mortalityor significant morbidity requiring hospital­ization occurred. Angular deformity, stric­ture of bile ducts and impacted stones werethe most frequent factors responsible forfailure or incomplete removal of retainedstones. Fluoroscopically guided percutane­ous interventional procedures with a pre­shaped angulated catheter are useful com­plementary procedures to surgery forpatients with intrahepatic stones. The majorbenefits of an individually angulated cathe­ter are safety and easy access to small pe­ripheral bile ducts.AUTHORS' ABSTRACT

Abstracts • 443

Volume 3 Number 2

GENITOURINARY

Percutaneous Transrenal UreteralOcclusion: Indication and Tech­nique. W. Hiibner, M. Knoll, P. Por­paczy. Ural Radial 1992; 13:177-180.(W.B., Department of Urology, PoliclinicHospital, Mariannengasse 10, A-1090 Vi­enna, Austria)

• Several techniques for achieving pallia­tive ureteral occlusion in cases of underlyingmalignant diseases are known to exist. Theauthors performed nine ureteral occlusionson seven patients, using two different tech­niques (occlusion by detachable balloon andby "Harzmann Olive"). Initially, completeocclusion of all ureters was attained; intwo cases a second occluding interventionhad to be carried out after a period of 6 and14 weeks. Six of seven patients enjoyed amarked improvement of their quality of lifeafter occlusion. Complications were down toa minimum. In comparison with other tech­niques described in the literature, Harz­mann's method seems to be the simplest, aswell as the most fully developed one. It mayalso be recommended for patients in an ad­vanced tumor stage.AUTHORS' ABSTRACT

Polyurethane Internal UreteralStents in Treatment of Stone Pa­tients: Morbidity Related to Indwell­ingTimes. S. R. EI-Faqih, A. B. Sham­suddin, A. Chakrabarti, et al. JUral1991; 146:1487-1491. (From the Divisionof Urology, College ofMedicine and KingKhalid University Hospital, Riyadh,Saudi Arabia)

• The morbidity and complications associ­ated with use of internal polyurethane ure­teral stents in a series of 290 stone patientstreated endourologically or with extracorpo­real shock wave lithotripsy were retrospec­tively reviewed. Of the 299 stents retrieved,141 were also tested for patency to relate therate ofluminal blockage with stent caliber,indwelling time, and clinical evidence of ob­struction in the stented tract. Stent indwell­ing times ranged from a few days to 18months: 11.3% were indwelling longer than6 months and 1.9% were lost to follow-up.Incrustation occurred in 9.2% of the stentsretrieved before 6 weeks, 47.5% indwelling 6to 12 weeks, and 76.3% thereafter. In 19cases over-all (6.4%) an auxiliary procedurewas required to decrease incrusted stoneburden and enable stent retrieval. Othercomplications included stent migration

444 • Journal of Vascular and Interventional Radiology

May 1992

(3.7%), infection (6.7%), and breakage(0.3%). Despite a 30% rate ofluminal block­age in stents retrieved after indwelling timesup to 3 months, the incidence of clinical ob­struction in stented tracts up to 3 monthswas 4%, confirming other reports that sig­nificant urine flow occurs around ratherthan through hollow, vented stents. Thesefindings underline the importance of re­stricting the use of stents to stone patientswho will be reliable at follow-up. Morbiditywas minimal if stent indwelling times didnot exceed 6 weeks.AUTHORS' ABSTRACT

Laparoscopic Varix Ligation. JamesF. Donovan, Howard N. Winfield. JUral1992; 147:77-81. (From the Departmentof Urology, University of Iowa Hospitalsand Clinics, Iowa City, Iowa)

• Varicocele, dilated veins in the pampini­form plexus, is frequently a contributingfactor in male infertility. The authors per­formed outpatient laparoscopic varix liga­tion in 14 patients (five bilaterally) withclinically evident varices and persistent oli­gospermia and/ or asthenospermia. Thespermatic artery was identified and pre­served in all but one varix ligation. Meaninterval to resumption of preoperative activ­ity levels was 3.4 days. On average, patientsconsumed 8.4 tablets of acetaminophen (325mg) with codeine (30 mg) during the recov­ery period. The procedure is effective anddecreases postoperative morbidity.AUTHORS' ABSTRACT

HEAD AND NECK

MR Imaging of Head and Neck Vas­cular Malformations. Franc;ois Gelbert,Marie Claire Riche, Daniel Reizine, et al.JMRI 1991; 1:579-584. (F.G., Depart­ment of Neuroradiology and TherapeuticAngiography, Hopital Lariboisiere, 2 RueAmbroise Pare, 75010 Paris, France)

• Between 1980 and 1990, 150 patientswith cervicofacial vascular malformationswere studied at the authors' institution withcomputed tomography, plain radiography,and angiography. Since 1989, 34 of thesepatients have also undergone magnetic reso­nance (MR) imaging. Capillary-venous he­mangiomas seem to be the best indicationfor the adjunctive use of MR imaging. Thevenous pouches, characteristic of this type oflesion, cause elevated signal intensity, well

seen on the T2-weighted images. Excellentfat and muscle differentiation with MR im­aging allows appreciation of the depth of ex­tension of these lesions and their delimita­tion from normal tissue. Arteriovenousmalformations (AVMs) are characterized byserpentine signal voids, indicative of thehigh flow rate of these lesions. Delimitationof the AVM nidus in the midst of the affer­ent and efferent dilated vessels is often dif­ficult. Study of immature angiomas with MRimaging should be restricted to lesions inspecific locations (eg, orbital, laryngeal).Lymphatic malformations showed eithertissular or cystic signal intensity changes.MR imaging does not replace other studiesbut represents an important complementarystudy for the delineation and diagnosis ofdeep extensions of vascular malformations,allowing better planning of therapy.AUTHORS' ABSTRACT

Combined Endovascular Emboliza­tion and Surgery in the Managementof Cerebral Arteriovenous Malfor­mations: Experience with 101 Cases.Fernando Vifmela, Jacques E. Dion, GaryDuckwiler, et al. J Neurosurg 1991; 75:856-864. (F.V., Service of EndovascularTherapy, University of California Schoolof Medicine, 10833 Le Conte Ave, Los An­geles, CA 90024)

• The authors describe their experiencewith 101 cerebral arteriovenous malforma­tions (AVMs) treated by means of endovas­cular embolization followed by surgical re­moval. Fifty-three patients presented withintracranial hemorrhage and 35 had sei­zures. Based on the classification of Spetzlerand Martin, two AVMs were grade I, 13 weregrade II, 26 were grade III, 43 were gradeIV, and 17 were grade V. Fifty-six AVMswere in the right hemisphere, 28 were in theleft hemisphere, 12 were in the corpus callo­sum, and five involved the cerebellum. In 50cases, presurgical obliteration of 50%-75%of the AVM nidus was achieved by emboliza­tion, and in 31 cases this percentage in­creased to between 75% and 90%. In 97 pa­tients (96%), complete surgical removal ofthe AVM was obtained. Morbidity resultingfrom preoperative endovascular emboliza­tion was classified as mild in 3.9% of thecases, moderate in 6.9%, and severe in1.98%. The death rate related to emboliza­tion was 0.9%. The immediate postsurgicalmorbidity was classified as mild in 5.9% ofthe cases, moderate in 10.8%, and severe in5.9%. The overall long-term morbidity wasmild in 5.9% of the cases, moderate in 6.9%,

and severe in 1.98%. Two patients (1.98%)died due to intractable intraoperative hem­orrhage and two (1.98%) as a result of post­surgical pulmonary complications.AUTHORS' ABSTRACT

Enlargement of Basilar Artery Aneu­rysms Following Balloon Occlu­sion-"Water-Hammer Effect": Re­port of Two Cases. Eddie S. K. Kwan,Carl B. Heilman, William A. Shucart,et aI. J Neurosurg 1991; 75:963-968.(E.S.K.K., New England Medical CenterHospitals, 750 Washington St, NEMCH#88, Boston, MA02111)

• Two patients with distal basilar aneu­rysms were treated with intra-aneurysmalballoon occlusion. After apparently success­ful therapy, follow-up angiograms demon­strated aneurysm enlargement with balloonmigration distally in the sac. Geometric mis­match between the base of the balloons andthe aneurysm neck together with transmit­ted pulsation through the 2-hydroxyl-ethyl­methacrylate (HEMA)-filled balloon directlycontributed to aneurysm enlargement. Inthis report, the authors discuss the prob­lems of progressive aneurysm enlargementdue to a "water-hammer effect" and the pos­sibility of hemorrhage following subtotalocclusion.AUTHORS' ABSTRACT

I PEDIATRICS

Central Venous Catheterization inInfants and Children with Congeni­tal Heart Diseases: Experiences with500 Consecutive Catheter Place­ments. Peter Mitto, Andreas Barankay,Paul Spath, et al. Pediatr Cardioll992;13:14-19. (J. A. Richter, Institut fUr Ana­esthesiologie, Deutsches HerzzentrumMiinchen, Lothstrasse 11, W-8000Miinchen 2, Germany)

• In a prospective study, results of centralvenous catheter (eVe) placements in a con­secutive group of 500 patients with less than20 kg body weight undergoing cardiac sur­gery were evaluated. The incidence of previ­ous cardiac surgery was 21%, and the inci­dence of factors preventing the primarypuncture of the right jugular or innominatevein was 13.4%. The anesthesiologists werefree to select the catheterization technique,site of puncture, and catheter type. All eveinsertions were performed prior to surgery

under continuous circulatory monitoringand optimal positioning of the anesthetizedpatient. Ninety-six percent of all catheteriza­tions were successful, 81% of them on thefirst attempt. In the 4% of cases in whichcatheterization failed, a CVC had to beplaced by the surgeon. Of all catheters, 66%were positioned via the right internaljugu­lar or innominate vein, 8% via the left, 16%via an external jugular vein, and 5% viaother veins. Seventy-six percent of CVC in­sertions were performed with the Seldingertechnique. Of the four catheter types used inthis study, double lumen catheters weremost frequently selected (38%). Placementof 22-gauge single lumen catheters was pre­ferred in infants with less than 5 kg bodyweight, in spite of their tendency to kink.Observed complications (10% arterial punc­ture, 4% hematoma, and 1% intrathoracicbleeding) never required immediate surgicalintervention. Careful selection of appropri­ate catheters, as well as extensive experienceand knowledge of the anatomical structuresinvolved in special heart defects, helped tokeep the risk of complications low.AUTHORS' ABSTRACT

Neonatal Aortic Thrombosis. MichaelD. Colburn, Hugh A. Gelabert, WilliamQuiiiones-Baldrich. Surgery 1992; 111:21-28. (M.D.C., Department of Surgery,UCLA Medical Center, 10833 Le ConteAve, Los Angeles, CA 90024)

• Thrombosis of the aorta in the neonateis a potentially catastrophic event. The inci­dence of this problem has increased concom­itantly with the widespread use of umbilicalartery catheters in the management of in­fants who are critically ill. The natural his­tory and appropriate management of thiscomplication has not been well established.This is due in part to the wide spectrum ofpresentations and lack of consensus regard­ing its classification. Aortic thrombosis mayvary from deposition of a fibrin sheath sur­rounding the length of an umbilical arterycatheter to aggregates of nonocclusivethrombus within the aorta or to completeocclusion of the aorta and concomitant oc­clusion of its main branches. The reportedtreatments recommended for this problemhave ranged from supportive care only tomandatory surgical intervention in all cases.This spectrum of advocated therapies hasresulted in considerable confusion regardingthe proper management of this problem.This paper presents two cases of neonatalaortic thrombosis: one case was treatedmedically and the other case was treatedwith surgical intervention. The authors re-

view these cases and the current literature,with specific attention directed towardshighlighting the critical elements involved informulating a reasonable approach to themanagement of neonatal aortic thrombosis.In addition, the authors offer an algorithmfor management of these patients accordingto the degree of aortic thrombosis, severityof systemic manifestations, and the generalcondition of each individual patient.AUTHORS' ABSTRACT

Renal Artery Stenosis in Children. L.Robinson, W. Gedroyc, J. Reidy, et al. ClinRadio11991; 44:376-382. (L.R., Radiol­ogy Department, Guy's Hospital, LondonSE19RT)

• In a large paediatric renal unit over thelast 14 years, 19 children (10 male and ninefemale, aged 1 week to 16 years; mean, 7years) with renal artery stenosis (RAS) wereevaluated. Transplant RAS cases were notincluded. All 19 children were hypertensive.In 10, this was an incidental finding. Basedon clinical findings and arteriography, thecauses of RAS included a middle aortic syn­drome (MAS) (n = 5), neurofibromatosis(n = 3), William's syndrome (n = 3), fibro­muscular hyperplasia (FMH) (n = 4), idio­pathic RAS (n = 2), and isolated branch ar­tery stenosis (n = 2). Previous studies havesuggested FMH is the commonest cause ofRAS in the paediatric population. In thisstudy the largest subgroup are MAS Wil­liam's syndrome children, in whom the an­giographic appearances were indistinguish­able. Where possible, management, bothsurgical and radiological, and eventual out­comes have been described.AUTHORS' ABSTRACT

In Utero Arterial Embolism from Re­nal Vein Thrombosis with SuccessfulPostnatal Thrombolytic Therapy.Brian W. Duncan, N. Scott Adzick,Michael T. Longaker, et al. J PediatrSurg 1991; 26:741-743. (N.S.A., Univer­sity of California, Department of Surgery,3rd and Parnassus, Rm 585-HSE, SanFrancisco, CA 94143-0510)

• Thromboembolic events in the pediatricage group occur most commonly in neo­nates, and newborns of diabetic mothers areparticularly at risk. The authors describe anewborn with right renal vein and inferiorvena cava thrombosis that apparently embo­lized across the foramen ovale antenatallywith resultant right brachial artery occlu­sion. The baby was delivered by cesareansection from an insulin-dependent diabeticmother. At the time of birth, there was se-

Abstracts • 445

Volume 3 Number 2

vere right arm ischemia with absent bra­chial and radial pulses. There was clinicalevidence of distal embolization with a"trash" lesion of the distal right middle fin­ger as well as a midforearm area of full­thickness skin loss. Ultrasound (US) demon­strated a right renal vein thrombosis and a95% occlusion of the inferior vena cava. Re­gional urokinase therapy was institutedthrough a lower extremity vein with a 5,000U/kg bolus and then 5,000 U/kg/h continu­ous infusion. Twelve hours of infusion ofurokinase led to clinical resolution of theright arm ischemia, with return of pulses.Follow-up US showed the right renal veinthrombosis and inferior vena cava clot to becompletely resolved. The right middle fingerand forearm lesions subsequently havehealed primarily. The authors report this asa case of in utero arterial embolization withsuccessful postnatal therapy using regionalurokinase infusion.AUTHORS' ABSTRACT

I TECHNOLOGY

Commentary Concerning Demon­stration of Safety and Efficacyof Investigational AnticancerAgents in Clinical Trials. Joyce A.O'Shaughnessy, Robert E. Wittes, Gre­gory Burke, et al. J Clin Onco11991;9:2225-2232. (J.A.O., National CancerInstitute, Bldg 10, Rm 12N226, Bethesda,MD 20892)

• Expeditious clinical development andapproval of new drugs that are beneficial topatients are matters of high priority. Therehas been a great deal of discussion withinthe oncology community about what shouldconstitute evidence of effectiveness of newanticancer agents for purposes of drug ap­proval. This commentary is intended to il­lustrate a variety of end points that can leadto approval of new anticancer agents for spe­cific clinical situations. Although the ulti­mate hope of antineoplastic therapy is pro­longation of life, there are other effects ofanticancer drugs that constitute clear clini­cal benefit and represent evidence of effec­tiveness. The guiding principle is that thebeneficial effects obtained from a new drugshould sufficiently outweigh the adverse ef­fects such that the potential risk:benefit ra­tio achieved by an individual patient is fa­vorable. The assessment of a new drugshould flexibly evaluate safety and efficacy inthe context of the specific clinical condition

446 • Journal of Vascular and Interventional Radiology

May 1992

being treated. Early discussions with theFood and Drug Administration and the Na­tional Cancer Institute are recommended toidentify prospectively the end points andtrial designs needed to demonstrate effec­tiveness of a new drug. The general princi­ples discussed will likely apply to the drugapproval process for other medical disci­plines as well.AUTHORS' ABSTRACT

Embolization with Steel Coils Usinga Saline Flush Technique. KohzohMakita, Shigeru Furui, Toshiyuki Irie, etal. Br J Radio11991; 64:708-710. (Fromthe Department of Radiology, NationalDefense Medical College, 3-2 Namiki,Tokorozawa, Saitama 359, Japan)

• A method using saline flush to push Gi­anturco steel coils through catheters is de­scribed and has been successfully used in 45patients. The saline flush technique requiresno precise matching of coils and catheters,solves problems associated with the conven­tional method, and simplifies the coil embo­lization procedure.AUTHORS' ABSTRACT

CONTRAST MATERIAL

A Comparison of Nonionic, Low-Os­molality Radiocontrast Agents withIonic, High-Osmolality Agents dur­ing Cardiac Catheterization. BrendanJ. Barrett, Patrick S. Parfrey, Hilary M.Vavasour, et al. N Engl J Med 1992; 326:431-436. (P. S. Parfrey, Division of Neph­rology, Health Sciences Centre, St. John'sNF AlB 3V6, Canada)

• Background. Nonionic, low-osmolalityradiocontrast agents are used frequentlybecause they are believed to be safer thanionic, high-osmolality agents, but they arealso more expensive. The authors conducteda randomized trial to compare the incidenceof adverse events after the administration ofionic, high-osmolality and of nonionic, low­osmolality radiocontrast agents during car­diac angiography. Methods. The authorscompared the need to treat patients for ad­verse reactions and the frequency and sever­ity of specific hemodynamic, systemic, andsymptomatic side effects in two groups ofpatients randomly assigned to receive eitherionic, high-osmolality or nonionic, low-os­molality radiocontrast material, and also in

366 patients who could not be randomized.Results. Treatment for adverse events wasrequired in 213 of 737 patients who receivedhigh-osmolality contrast agents (29%) butin only 69 of 753 patients who receivednonionic agents (9%) (95% confidence inter­val for the percentage difference, 15.9%­23.6%). Hemodynamic deterioration andsymptoms also occurred more often in thehigh-osmolality group, as did severe or pro­longed reactions (2.9% as compared with0.8% in the nonionic group; P = .035). Thesevere reactions were largely confined to pa­tients with severe cardiac disease. Multivari­ate analysis showed that the presence of se­vere coronary disease and unstable anginawere predictors of clinically important ad­verse reactions. If all patients in this ran­domized trial had been given nonionic con­trast material, the incremental cost perprocedure would have been $89. Conclu­sions. Nonionic, low-osmolality contrast ma­terial is better tolerated during cardiac an­giography than ionic, high-osmolalitycontrast material. Since cost constraintsmay prevent the universal use of nonioniccontrast material, its selective use in pa­tients with severe cardiac disease could beconsidered.AUTHORS' ABSTRACT

Safety and Cost Effectiveness ofHigh-Osmolality as Compared withLow-Osmolality Contrast Material inPatients Undergoing Cardiac An­giography. Earl P. Steinberg, Richard D.Moore, Neil R. Powe, et al. N Engl J Med1992; 326:425-430. (E.P.S., Johns Hop­kins University, 1830 E Monument St,Rm 8068, Baltimore, MD 21205)

• Background and Methods. Low-osmolal­ity contrast agents produce fewer hemody­namic and electrophysiologic alterationsduring cardiac angiography, but they are 20times more expensive than high-osmolalitycontrast agents. In a randomized, double­blind trial comparing a nonionic, low-osmo­lality contrast agent (Omnipaque 350) witha high-osmolality agent that does not avidlybind calcium (Hypaque 76) in 505 patientsundergoing cardiac angiography, the au­thors determined the incidence of minor,mild, moderate, and severe adverse reac­tions, identified risk factors for such reac­tions, and evaluated the cost effectiveness ofvarious strategies for the use of contrast ma­terial. Results. The 253 patients who re­ceived a high-osmolality contrast agent werethree times more likely to have a moderateadverse reaction (95% confidence intervalfor the relative risk, 1.6-5.5) but no more

likely to have a severe reaction (95% confi­dence interval, 0.2-2.3) than the 252 pa­tients who received a low-osmolality agent.All 10 severe reactions occurred in patientswho were older than 60 years or had unsta­ble angina. Patients with these characteris­tics were also 3.5 times more likely (95%confidence interval, 1.8-6.8) to have a mod­erate reaction (44 of 310 patients, or 14%)than those without either characteristic(eight of 195 patients, or 4%). The authorsestimated that the incremental cost of eachmoderate reaction avoided would be $1,698with a strategy that involved giving a low­osmolality contrast agent only to patientswho were over 60 years of age or had unsta­ble angina, instead of giving a high-osmolal­ity agent to all patients. The incrementalcost per moderate reaction avoided by givinga low-osmolality contrast agent to all pa­tients rather than only to those over 60 orwith unstable angina would be $5,842. Con­clusions. The use of contrast agents withlow rather than high osmolality during car­diac angiography reduces the risk of moder­ate, but not of severe, adverse reactions tothe agent used. A strategy of reserving low­osmolality contrast agents for use in pa­tients at high risk for adverse reactionswould be more cost effective than one re­quiring their use in all patients.AUTHORS' ABSTRACT

Incompatibility of Water-SolubleContrast Media and IntravascularPharmacologic Agents: An in VitroStudy. Seung Hyup Kim, Ho Kyu Lee,Man Chung Han. Invest Radio11992; 27:45--49. (S.H.K., Department of DiagnosticRadiology, Seoul National UniversityHospital, 28 Yongon-Dong, Chongno-Gu,Seoul 110-744, Rupublic of Korea)

• In vitro incompatibilities between ninewater-soluble contrast media and 21 intra­vascular pharmacologic agents were investi­gated using naked-eye observation and acentrifuge. Most of the previously reportedincompatibilities were verified, and a fewnew incompatibilities were discovered: phen­tolamine mesylate with diatrizoate sodium,diatrizoate meglumine, ioxaglate, andiothalamate; diatrizoate meglumine withdiazepam and meperidine hydrochloride;and diatrizoate sodium with meperidine hy­drochloride. There were no incompatibilitieswhen the pharmacologic agents investigatedwere mixed with ioxithalamate, iopromide,iopamidol, and iohexol.AUTHORS' ABSTRACT