9 cases, 2 deaths (22%) occurred in patients with exten­

sive hepatic replacement by tumor where embolo­therapy was used in an attempt to arrest tumor growth.

CONCLUSION: Hepatic embolotherapy in patients with

neuroendocrine tumors metastatic to the liver may be

used for control of pain, as well as hormonal symptoms.This therapy should be used cautiously, if at all, in an

attempt to control progression of disease in the other­

wise asymptomatic patient.

3:45 pm

Hepatic Arterial Chemoembolization WithStreptozotocin in Patients With Liver Metastasesof Endocrine Digestive TumorsAlban Denys, MD, Qichy, France. Sophie Dominquez,

MD. Annie Sibert, MD. Philippe Ruzniewski, MD.

Valerie Vilgrain, MD. Yves Menu, MD

PURPOSE: To evaluate the efficacy of chemoemboliza­

tion of liver metastases from digestive endocrine tumors

using Streptozotocin (STZ). This drug is known as the

most efficient systemic chemotherapy of this disease.

MATERIAL AND METHODS: 15 patients with progressive

liver metastases from carcinoid tumors (n = 8) or islet cell

carcinomas (ICC, n = 7) were prospectively included in

this study. STZ was administered under general anesthesia

in emulsion wit Lipiodol and associated to embolizationwith Gelfoam particles. This treatment was repeated in 12

cases 2 to 6 times (median 3) (one session in 3 cases).

Median follow-up was 16 months (1-49).

RESULTS: An objective response according to the WHOcriterias was obselved in 8 patients (53% median dura­

tion 10, 5 months), stabilization in 3 and progression in

4 patients. Carcinoid syndrome disappeared in 3 out of 5

cases during 17, 10 and 11 months.

CONCLUSION: STZ seems to be more effective thandoxorubicin for palliative treatment of liver metastases

from digestive endocrine tumors, probably because ofthe better specificity of this drug for endocrine tumors.

4:00 pm

Ethanol Ablation of Liver MetastasisAttilio Solinas, MD, San Diego, CA • Horacio R.

DAgostino, MD. E. Papi, MD. C. Malaspina, MD.

P. Roselli, MD • R. Modesto, MD

PURPOSE: To evaluate the safety and efficacy of percu­

taneous ethanol injection (PEI) in the management ofliver metastasis.

MATERl41S AND METHOD: 31 patients with liver metasta­sis were assessed by an oncology team and underwent PElas part of their treatment. Primary malignancies included

colorectal carcinoma (20 patients), breast (3 patients), gas­

tric (2 patients), ovarian (2 patients), melanoma (2 pa­

tients), prostate (1 patient), and lung cancer (1 patient). All

patients had control of their ptimary tumors and no more

than 3 liver lesions. PEl was performed in multiple sessions

(27 patients) or a single session under general anesthesia (4patients, ethanol volume injected 50-120 ml). Treatmentresponse was evaluated by tumor markers levels, dynamicCT and fine needle biopsy.

RESULTS: 17 patients were alive with no active liver

disease (range 3 to 30 months, median 6 months); 6

patients were alive with persistent liver disease (range 10

to 15 months, median 10 months); 8 patients died from

disease progression (range 4-17 months, median 6

months). PEl adverse effects were moderate to severe

pain and fever. Tumor markers serum levels and post

PEl biopsy results correlated with disease activity.

CONCLUSION: PEl was a safe an effective method for

ablation of liver metastasis in selected patients.

4:15 pm

Percutaneous Hot Saline Injection Therapy:Effectiveness in Chemoembolization-LimitedLarge Hepatocellular CarcinomaHyun-Ki Yoon, MD, Seoul, South Korea. Ho-Young

Song, MD • Kyu-Bo Sung, MD. Yong-Ho Auh, MD

PURPOSE: To report on the efficacy of percutaneous hot

saline injection therapy (PSrD in the treatment of che­

moembolization-limited large hepatocellular carcinoma(HCC).

MATERIALS AND METHODS: Twenty-nine patients with

31 HCCs underwent PSlT. Physiologic saline was mixed

with contrast medium and Lipiodol, boiled, and was

injected into the tumor. Mean tumor diameter was 7.0cm. Follow-up computed tomography, angiography,

and alpha-fetoprotein level measurement were per­

formed in every three months. Regression rates were

analyzed according to the diameter (Group A, <5 cm;

Group B, 5-10 cm; Group C, >10 cm), location (centralvs. peripheral), and growth pattern (encapsulated vs.infiltrative) of each HCC.

RESULTS: The regression rate (RR) for all tumors was 42%

(13/31). RRs for group A,B, and C were 86%, 45%, and 15%,respectively (P < 0.05). RRs for centrally and peripherallylocated tumors were 73% and 25% (p < 0.05). RRs forencapsulated and infiltrative tumors were 48% and 17%

(P > 0.05). No major complications were encountered.

CONCLUSION: PSlT is a safe and favorable alternativetreatment for large HCC when transcatheter arterial che­

moembolization is not feasible or has failed.

Wednesday, March 4, 19988:00 am-9:30 am

Scientific Session 19Risk Reduction in Diagnostic AngiographyModerator: John A. Kaufman, MD

191

192

8:00 am

Optimizing Imaging Technique for GadoliniumContrast AngiographyDavid]. Spinosa, MD, Charlottesville, VA. Gary D.

Hartwell, DSc • J. Fritz Angle, MD. Klaus C. Hagspiel,MD. SureshJ. Agarwal, PhD. Alan H. Matsumoto,

MD

PURPOSE: To determine optimal imaging techniqueswhen using gadopentetate dimeglumine as an intravas­cular contrast agent.

MA TERIALS A flow phantom was constructed fromplexiglass and contained 3 mm plastic tubing to simulatea blood vessel. A 1 inch aluminum wedge was used tosimulate the bony spine. The phantom was submergedin 20 cc of water to simulate a soft tissue environment. A0.5 mmol/L solution of gadopentetate dimeglumine wasinfused through the tubing during the image acquisition.An angiography unit with a 40 cm image intensifier anda high resolution digital imaging system was used toobtain DSA images at 2 frames per second. DSA imageswere obtained at 77 kV, 81 kV, 96 kV, 102 kV, 109 kV,117 kV, and 125 kV. The amount of gadolinium contrastrelative to the background contrast was determined bymeasuring video signal in mV and reported in percentcontrast for each kV.

RESULTS: The calculated percent gadolinium contrast at77 kV, 81 kV, and 96 kV equaled 13%. The calculatedpercent gadolinium contrast at 102 kV equaled 11%, at109 kV equaled 9%, at 117 kV equaled 7%, and at 125 kVequaled 5%. The percent contrast at 96 kV was calcu­lated in the presence of a radiation reducing copper filter(0.3 mm) and determined to be unchanged (13%).

CONCLUSION The flow phantom model demonstratesthat intravascular gadopentetate dimeglumine contrastimages are optimized at 77 to 96 kV. DSA images ob­tained at 96 kV with the addition of a 0.3 mm copperfilter should produce optimal contrast while minimizingthe radiation dose to the skin of the patient. These resultsreflect a compromise between the higher k-edge of ga­dolinium-based contrast and the lower sensitivity of thecesium iodide crystals in the image intensifier at higherkVs.

8:15 am

Optimization of Gadolinium AngiographyDominic Carl Yee, MD, Tucson, AZ. Julie Marie

Zaetta, MD

PURPOSE: To determine adequate gadolinium (Gd) con­trast concentration and radiographic technique to per­form renal arteriography.

MATERIALS AND METHODS: A single 20 kg canine un­derwent repeated abdominal aortic arteriography toevaluate the renal arteries using different concentrationsof gadolinium and radiographic technique.

The contrast injections were all performed using a

power injector through a 5 Fr. Pigtail catheter with a flowrate of 5 cels for a total volume of 15cc. Gd arteriogramswere performed with concentrations of 100% (0.5mM/ml gadopentetate dimeglumine), 75%, 50%, 25%,and 12.5%. Subsequently full strength Gd arteriogramsutiliZing Kvs of 90, 80, 70, 60 were then performed. Acontrol iodine contrast arteriogram using full strengthIoxilan (300mg lim]) was also performed.

The images were reviewed and graded by 6 angiog­raphers. Reviewers were asked to rank the images byoverall quality. They were then asked which imageswould be acceptable to rule out a renal artery stenosisgreater than 75% and if they were sufficient enough toevaluate the segmental branches.

RESULTS: The iodine contrast angiogram was consis­tently chosen as the best angiogram with the full strengthGd angiogram being second best. 83% of the observersfelt 70 Kv to be the best technique for performing Gdangiography. 100% felt that 75% strength Gd was suffi­cient to evaluate the main renal arteries for stenosis.However, only 50% felt that this concentration of Gd wassufficient for evaluating the segmental branches.

CONCLUSION Gadolinium can be used effectively forperforming angiograms. The concentration of the Gdmay be decreased to 75% when evaluating larger branchvessels of the aorta. In addition, 70 Kv provides theoptimal voltage for performing renal angiography.

8:30 am

Gadolinium-Based Digital SubtractionAngiography: Experience in Twenty-one PatientsJulie M. Zaetta, MD, Tucson, AZ. Richard A. Baum,MD. ZivJ. Haskal, MD. Michael C. Soulen, MD.Richard D. Shlansky-Goldberg, MD

PURPOSE: To evaluate the utility of using gadolinium(Gd) as a contrast agent for digital subtraction angiogra­phy (DSA) in patients with renal insufficiency or allergiesto iodinated contrast media.

MATERIALS AND METHODS: Twenty-one patients un­derwent gadodiamide (Omniscan) digital subtraction an­giography. Indications for gadolinium use included pa­tients with renal insufficiency (17 patients), previousanaphylactic reaction to iodinated contrast agents (3

patients), and current use of metformin HCL (Gluco­phage) (1 patient). The use of additional contrast agentswas at the discretion of the interventionalist. Angiogramswere evaluated on a five point scale for diagnostic qual­ity.

RESULTS: Fourteen patients had Gd-arteriography, andseven patients had Gd-venography. In ten patients ga­dodiamide was the sole contrast agent used (Gd-arterio­grams-4, Gd-venograms-6). In the remaining elevencases, Gd-DSA was supplemented with an alternativecontrast media. In nine patients the nonionic contrastmedium iohexol diluted to 50% was used and in two

patients carbon dioxide was used. Diagnostic qualitywas variable, but in general detail was least satisfactorywith Gd-abdominal aortograms, while those studies ob­tained on a subselective bases tended to be comparableto standard iodinated contrast angiograms. There wereno immediate complications related to the intraarterialadministration of gadolinium.

CONCLUSION Gadolinium is a useful alternative con­trast agent for DSA in patients with renal insufficiency orsevere reactions to iodinated contrast medium.

8:45 am

Prophylactic Intra-Procedural Hemodialysis inPatients at Risk for Contrast-Induced RenalFailureDarryl Adam Zuckerman, MD, St. Charles, MO •Marcos Rothstein, MD

PURPOSE: To detennine the effectiveness of hemodial­ysis during angiography in preventing the developmentof contrast-induced acute tubular necrosis.

MATERIALS AND METHODS: Twenty-one diabetic pa­tients with underlying renal insufficiency (averagebaseline serum creatinine 3.4 mg/dlj range 1.9-6.5)underwent arteriography. Average iodine load was 58grams. Via a temporary venous catheter, hemodialysiswas performed in the angiography suite using a hol­low-fiber dialyzer (0.8-1.0 square meter membrane)

with portable reverse osmosis. Blood flows of 250­300 mllmin were used. Dialysis was started 5 minutesprior to the initial administration of contrast and wascontinued for 45-60 minutes after the final contrastinjection. Arterial and venous iodine concentrationswere noted during and immediately after the arterio­gram and serum creatinines were monitored in thefollow-up period.

RESULTS: Serum creatinine declined on post-arterio­gram day 1 to 2.9 mg/dl, returning to near baseline onday 2 0.3 mg/dO and did not rise subsequently. Ef­fectiveness of dialysis was shown by iodine concen­trations which declined by 32% from peak arterial tovenous and by an additional 21% as measured on a 5hour post-procedural assay. No patient in this ex­tremely high-risk group deteriorated into worseningrenal failure and acute or permanent dialysis wasavoided.

CONCLUSIONS: Peri-procedural dialysis may be an ef­fective means to prevent contrast-induced renal failure inhigh-risk patients undergoing contrast examinations.

9:00 am

Bacteremia Associated With Invasive RadiologicalProceduresHans-]oachim Wagner, MD, Marburg, Germany.Heiko Aifke, MD. Martin Hoppe, MD. Klaus ]ochenKlose, MD

PURPOSE: Prospective evaluation of the incidence ofbacteremia associated with invasive radiological proce­dures.

MATERIAL AND METIfODS: Blood cultures were col­lected from hundred patients (62 men, 38 women; meanage 65 ::':: 14 years) undergoing intraarterial angiography(N = 50), PTA (N = 30), or percutaneous transhepaticbiliary drainage (PTBDj N = 20). Blood samples were

obtained before the procedure (To), immediately afterpuncture of the vessel or bile duct (T1), at the end of theprocedure (Tz), and 30 minutes after the end of theprocedure (T3).

RESULTS: The overall rate of bacteremia was 200/0. Diag­nostic angiography was associated with a 160/0 rate oftemporary bacteremia (no positive T3 samples), PTAwith a 270/0 rate (no clinically significant infectious dis­ease), and PTBD with a 100/0 rate (5% cholangitis withsepticemia). We isolated: Staphylococcus (S. epidermi­

dis: N = 7, S. spec.: N = 3, S. aureus: N = 1), Strepto­coccus (N = 2), Propionibacterium acnes (N = 5), E. coli(N = 1), Enterococcus (N = 1), Enterobacter (N = 1),and Clostridium perfringens (N = 1). Despite the patientwith cholangitis no patient had an infectious complica­tion.

CONCLUSION Bacteremia occurs frequently during in­vasive radiological procedures. We advocate strictlyaseptic procedures and antibiotic prophylaxis in case ofstent implantation.

9:15 am

The Utility of Hemostatic Collagen Plug Device inNon-Cardiac AngiographyKyran Dowling, MD, Albany, NY. Brian F. Stainken,

MD. Gary P. Siskin, MD. Allen Herr, MD. Valerie S.

Mandell, MD

PURPOSE: The role of collagen plug devices to seal theangiographic arteriotomy in non-cardiac angiographyhas yet to be defined. The purpose of this study is toretrospectively review our experience with one particu­lal' collagen plug device to help determine its utility in aVascular Radiology practice.

MATERIALS AND METIfODS: The Angio-Seal (Sher­wood, Davis & Geck) collagen plug device was used.The device delivers a flat rectangular anchor which isbioabsorbable within the artery; this is sealed with acollagen plug which is deposited outside the artery. Allinterventional radiology attendings were first trained onan animal sheep model. Success of deployment, coagu­lation status and heparinization, complications, need forcompression and case make-up were evaluated.

RESULTS: The collagen plug device was successfully

deployed in 21 out of 22 attempts (950/0). No groincompression was necessary in 19 out of 21 cases (90%).Complications included one 3cm hematoma requiringno further treatment. "Eight cases were perfonned in

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194

order to continue heparin in an uninterrupted fashion

after endovascular interventions. Four cases of multipletrauma were performed to expedite movement of the

patient to the operating room. The remaining cases werediagnostic in nature. The average time of deployment

was between one to two minutes.

CONCLUSIONS: Apparent indications for this particularcollagen plug device in a Vascular Radiology practicemay include: The need to provide uninterrupted heparin

therapy post angioplasty or stent, large sheath utiliza­

tion, and the need to move patients immediately to

surgery or to facilitate movement of patients who will

need more diagnostic exams.

Scientific Session 20

Stents - Experimental StudiesModerator: P. Macke Consigny, PhD

8:00 am

A Comparison of a Balloon Expandable StainlessSteel and a Self-Expanding Nitinol Stent Relativeto Vessel Size in the Arterial System of the SwineAnimal ModelAnthony Charles Venbrux, MD, Baltimore, MD.

Adam B. Winick, MD. Philip Rand Brown, DVM.

Carol A. Prescott, RN. Carolyn A. Magee, BS

PURPOSE: To compare the degree of hyperplasia afterpercutaneous placement of the balloon expandable

Palmaz stent and the self-expanding Nitinol stent relativeto vessel size in the iliac arteries of swine.

MATERIALS AND METHODS: After baseline angio­graphic measurements correlated with intravascular ul­trasound (IVUS); Palmaz stents (Symphony, Boston Sci­entific, Medi-tech, Watertown MA) were placed in theiliac arteries of six swine. lVUS was use to determine thestent diameter to within 10-30% oversizing. lVUS andangiography were performed before and after stent de­ployment, and prior to sacrifice. Two swine were sacri­ficed at four, two at six, and two at eight weeks after

stent deployment. lVUS measurements each included

the proximal, mid and distal stent.

RESULTS: All stents were successfully deployed. No throm­bosis was observed at follow-up. There was no statistical

difference between the degree of intimal hyperplasia of the

two stent types based on IVUS at four, six and eight weeks.

Angiographic measurements showed only statistical differ­ence at the eight week study interval.

CONCLUSION: Using IVUS as a means of sizing, there is

no statistical difference in the degree of intimal hyper­

plasia of the Palmaz stent and the Nitinol stent in swine

iliac arteries.

8:15 am

Histopathologic Effects of a BioabsorbableVascular Stent in the iliac Arteries of Swine: A

Feasibility StudyMartin Geza Radvany, MD, Baltimore, MD. Anthony

Charles Venbrux, MD. Phillip Rand Brown, DVM.

Carolyn Anne Magee, BS

PURPOSE: To evaluate the histopathologic effects of abioabsorbable stent in the iliac arteries of swine.

MATERIALS AND METHODS: After baseline angiogra­phy, a graft conduit (W.L. Gore, Flagstaff, AZ) was sur­gically affixed to the aorta. Through this, a metallic stent(Palmaz, Johnson and Johnson, Warren, NJ) was de­ployed as a control. Bioabsorbable stents, a co-polymer

of lactide and caprolactone, (B. Braun Vena Tech Inc,Evanston, Il) were deployed in the iliac arteries of sixswine. Heparin was administered to all animals duringstent deployment and aspirin post deployment to 3/6swine. Angiography was performed after stent place­ment and before sacrifice (l day to 10 weeks).

RESULTS: Nine bioabsorbable stents were deployed insix animals. No occlusive thrombus was identified ineither group. light microscopy demonstrated minimalinflammatory response. The neo-intima of the bioab­

sorbable stents consisted of organized thrombus ratherthan de novo proliferation and migration of subintimalmyofibroblasts seen with metallic stents. Angiographi­

cally, lumen narrowing was significantly reduced in theaspirin treated group.

CONCLUSION: Bioabsorbable stents do not induce thesame type of intimal hyperplasia as is seen with metallicstents. This is reduced with aspirin. Bioabsorbable stents

cause only minimal inflammatory response.

8:30 am

Prevention of Neointimal Hyperplasia by TaxolLindsay Machan, MD, Vancouver, BC, Canada.

Pierre Signore, PhD. Peter Bromley, MD. Bill Hunter,

MD

PURPOSE: To evaluate the ability of a slow release poly­mer containing taxol to prevent neointimal hyperplasiaafter balloon injury or stent insertion.

MATERIAL AND METHODS: Balloon injury was createdin the left common carotid artery of 70 Wistar rats. Theremaining 60 were randomized into groups of 10 eachimmediately receiving a wrap of EVA film, EVA film/20%taxol, PCl paste, PCl pastel20% taxol, PCl block, or PClblock!20% taxol applied directly to the adventitia of theinjured artery. 5 animals from each group were sacrificedat 14 or 28 days post balloon injury. Taxol coated me­tallic stents were inserted into the iliac artery of 6 do­mestic swine. Three were sacrificed at 4 weeks, three at

8 weeks.