292

Poster No. 218

Transluminally Placed Endovascular Grafts forVenous Lesions in Patients on HemodialysisJinho Kim, MD, Eugene, OR. Robert C. Shely, MD •Stephen F. Quinn, MD

PURPOSE: This report summarizes a feasibility studyusing transluminally placed endovascular grafts (TPEG)using pre-expanded polytetrafluoroethylene (PTFE) totreat venous abnormalities in patients on hemodialysis.

MATERIALS AND METIfODS: Seventeen patients withperipheral (n = 11) or central (n = 6) venous lesionswere treated with TPEG devices. Covered Gianturcostents were used for the central lesions and coveredPalmaz stents were used for central lesions. Venousabnormalities included vascular rupture after balloonangioplasty or surgical thrombectomy (n = 4), stenosisassociated with an aneurysm (n = 2), and occlusivedisease and central stenoses not responsive to balloonangioplasty (n = 11).

RESULTS: The mean primary patency period was 37days. The mean secondary patency period was 215 days.At 60, 180, and 360 days the primary and secondarypatency rates were 40%, 32%, and 32%, and 70%, 55%,and 39%, respectively. Follow-up studies have shownvarious outcomes of the implanted TPEG devices. Out­comes have included stenoses within the TPEG (n = 2),stenoses central to the TPEG (n = 1), stenoses peripheralto the TPEG (n = 3), acute thrombosis extending to theTPEG without a stenosis (n = 1), graft abandoned withpatent TPEG (n = 6), and TPEG patent within primarypatency period at last follow-up (n = 4).

CONCLUSION The TPEG devices made with pre-ex­panded PTFE appear to be safe in the short term, do notprevent progressive dialysis access site failure, and needto be compared to PTA and endovascular stenting in arandomized prospective trial.

Poster No. 219

Results of Dialysis Access Graft Recanalization with

a Combined Pulse Spray-Balloon Catheter SystemMark W Wilson, MD, San Francisco, CA. VishalBhagat, MD. Robert K. Kerlan, MD • Jeanne M.

laBerge, MD. Roy L. Gordon, MD

PURPOSE: To evaluate a new combined pulse spray­balloon catheter system (PECS) in the thrombolysis andrecanalization of occluded dialysis access grafts, com­pared with standard methods.

MA 1ERIALS AND METIfODS: Seven adult patients wererandomly selected over 12 months to undergo recanali­zation of eight occluded dialysis access grafts using thePBCS. The system is composed of two 5F multi-sideholeinfusion catheters with a 6 X 3-cm balloon attached tothe tip of one and a lO-mm spherical balloon attached tothe tip of the other. The catheters were introduced intothe grafts in crossed catheter fashion and directed at the

venous and arterial anastomoses, respectively. Afterpulse-spray administration of a urokinase/heparin mix­ture, balloon sweeping of the graft and balloon dilationof any anastomoses were performed by the same cath­eters, using their built-in balloon components. Duringthe same period, 28 other dialysis access grafts weretreated using the standard technique of exchanging theinfusion catheters for a standard 6-mm balloon catheterto dilate any stenoses and a 3F Fogarty catheter to sweepout the arterial plug and graft thrombus. The results fromthe two groups were compared in terms of duration ofprocedure, success rate, dose of urokinase, and dose ofheparin.

RESULTS: The mean duration of procedure in the PECSgroup was 48 minutes compared to a mean of 72 min­utes for the control group (p < 0.01). The success rate inthe PBCS group was 87.5% compared to 89% in thecontrol group. There were no significant differences inthe amounts of urokinase or heparin administered.

CONCLUSIONS: Use of the PECS significantly decreasedthe duration of the dialysis graft recanalization proce­dure in this small set of patients compared to controls.Success rates, urokinase dose, and heparin dose werenot Significantly different.

Visceral InterventionPoster No. 220

Comparison Between Cutting- and Aspiration­Type Needles for CT-Guided Biopsy of Small LungNodulesKenji Ibukuro, MD, Tokyo, Japan. RiichiroTakanashi, kID. Toshitaka Tsukiyama, MD

PURPOSE: To compare the 20G cutting-type biopsy nee­dle (CTBN) with the 21G aspiration-type biopsy needle(ATEN) for CT-guided lung biopsy in terms of size ofspecimen on the preparation (slide glass), ratio of diag­nostic malignant tissue to whole specimen, and diagnos­tic value.

MA1ERIA1S AND METIfODS: We performed CT-guidedlung biopsies in 56 patients with small lung nodulesbetween September 1995 and July 1998. The diameter oflung nodules ranged from 0.5 to 2.0 cm (mean 1.5 cm).Thirty-seven nodules were diagnosed as malignant; 19nodules were benign. Thilty-three nodules were corre­lated with surgical specimens, and 23 nodules wereclinically diagnosed. To obtain histologic specimens, a20G CTBN was used in 33 patients and a 21G ATEN in23 patients. The longest diameter of the specimen onpreparation was measured microscopically and classi­fied as A, <2 mm; B, 2 to 4 mm; or C, ~4 mm. The ratioof diagnostic malignant tissue (tissue excluding normallung tissue, blood, and tumor necrosis or fibrosis) towhole specimen was measured microscopically. Accu­racy, sensitivity, and specificity for malignant diseasewere assessed.

RESULT: For the 20G CTBN, there were 6 specimens ingroup A, 8 in group B, and 19 in group C; for the 21GATBN, there were 16 specimens in group A, 5 in groupB, and 2 in group C (p < 0.01). The ratio of diagnosticmalignant tissue to whole specimen was 55% Jor the 20GCTBN and 42% for the 21G ATBN) (p = NS). The accu­racy, sensitivity, and specificity were 96%, 95%, and100% for the 20G ·CTBN and 73%, 60%, and 100% for the21G ATBN (p < 0.05)

CONCLUSION The 20G CTBN provided more histologicspecimen and better diagnostic value compared with the21G ATBN for CT-guided biopsy of small lung nodules.

Poster No. 221.Percutaneous PolymethylmethacrylateVertebroplasty in the Treatment of Osteoporoticand Neoplastic Vertebral Body CompressionFractures in Patients with ConcomitantComplicating Anatomy and Disease StatesJ. Kevin McGraw, MD, Sylvania, OH. Jeffrey M.

Boorstein, MD, PhD

PURPOSE: To describe novel successful technical andprocedural variations from the standard percutaneousvertebroplasty technique and follow-up examinationfor patients with osteoporotic and malignant vertebralcompression fractures with concomitant complicatinganatomy and disease states precluding standard diag­nostic and therapeutic deployment techniques.

i"\1A TERIALS AND METHODS: New techniques, includingthe use of gadolinium and carbon dioxide as contrastmaterials for paraspinal venography in iodine-allergicand nephropathic patients, paraspinal approaches in pa­tients with pedicle fractures, combined vertebroplastyand surgery for patients with dual symptomatic lesions,and optimal MR imaging sequences for altifact-free fol­lOW-Up examinations, are applied to 17 patients with 18painful vertebral fractures over a 2-year period. Thevertebroplasty technique involves percutaneous transpe­dicular or paraspinous puncture of the symptomatic ver­tebral body, the performance of intravertebral biopsyand venographic contrast injection, and injection ofpolymethylmethacrylate into the vertebral body.

RESULTS: The procedural variations were technicallysuccessful in all patients, with no morbidity or mortality.All patients reported significant pain relief follOWingtreatment.

CONCLUSION Vertebroplasty remains a valuable tech­nique in the treatment of painful osteoporotic and neo­plastic compression fractures, providing acute pain reliefand increased mobility, even in patients who cannotundergo standard vertebroplasty techniques due to con­comitant complicating anatomy and disease states.

Poster No. 222

A New Covered Metallic Stent for Malignant BiliaryObstruction: Preliminary Clinical EvaluationTetsuya Yoshioka, MD, Kashihara, Japan. Hiroshi

Sakagucki, MD • Hideo Uchida, MD • Shiro Makutani,

MD. Takehiro Tanaka, MD. Hajime Ohishi, MD

PURPOSE: To evaluate a new covered metallic stent formalignant biliary obstruction.

i"\1A TERJALS AND METHODS: The stents were placed in26 patients (14 men and 12 women, age 45-84 years,mean 68) with malignant biliary obstruction. The ob­structive jaundice was due to carcinoma of the bile ductin eight patients, carcinoma of the pancreas in eight,hilar metastases in four, carcinoma of the gallbladder intwo, hepatocellular carcinoma in two, carcinoma of thepapilla in one, and liver metastases in one. The stent isconstructed of an elastic alloy with gold coating andformed into a cylindrical spiral zigzag configuration bylaser cutting. The stent is completely covered with thepolytetrafluoroethylene membrane on both inner andouter surfaces, except for 10 mm at the top and bottom.Two types of stent were used: 45 mm in length and 10mm in fuJly expanded diameter, and 70 mm X 10 mm.The stent was implanted through a 9F introducer andtranshepatically.

RESULTS: Stents were successfully placed in all patients.All stents had adequate expansile force, moderate flexi­bility, and good radiopacity. No trouble was encoun­tered. Twenty-five patients became free of an externaldrainage catheter, except one patient with stent occlu­sion. Patency rate at 1 year was 92%. Complications wereobserved in 16% of four patients, including stent occlu­sion at 1 week and 48 days after stenting in two andcholangitis in two.

CONCLUSION Our results suggest that a new coveredstent can be reliably and safely deployed transhepati­cally in the biliary system. The stent appears to have ahigh initial technical success rate, and the short-termpatency appears promising compared with that prOVidedby other metallic stents.

Poster No. 223

Transcatheter Arterial Chemoembolization withEpirubicin and SMANCS-Lipiodol forHepatocellular CarcinomaTakashi Ihaya, MD, Tottori City, Japan. TomohisaOokawa, MD

PURPOSE: To evaluate therapeutic effects and side ef­fects of transcatheter arterial chemoembolization (TACE)with epirubicin (EpiADM) and zinostatin stimalamer(SMANCS)-Lipiodol for patients with hepatocellular car­cinoma (HCC).

i"\1A TERlALS A/llD METHODS: Eighty patients with HCChave been treated with TACE using EpiADM andSMANCS-LipiodoJ. They consisted of 52 men and 28women with a mean age of 66.9 years. We pelformedsuperselective TACE with gelatin sponge after injectionof EpiADM/SMANCS-Lipiodol mixture. Responses to thetherapy were evaluated on the basis of survival rates,and 45 patients underwent follow-up angiography. Infour patients who underwent hepatic resection afterTACE, histopathologic examination was performed.

293

294

RESULTS: TACE limited to the tumor-bearing subsegmentor segment was performed in 42 patients. There was nosevere side effects or complications compared with con­ventional TACE, except one case of hepatic biloma for­mation. The I-year and 2-year survival rates were 80.6%and 45.6%, respectively. Histopathologic examinationafter hepatic resection showed no viable tumor cells inthe specimen; intimal necrosis, edema, degeneration,and thrombi formation were seen in the hepatic arteriesand also in the portal veins surrounding tumor tissue.Obstruction of the hepatic artery and portal vein in theembolized segment was recognized in 46.7%, and in22.2% of the patients who underwent follow-up angiog­raphy. A~P shunt was demonstrated in 33.3% of them onthe hepatic angiogram and/or CT during angiography.

CONCLUSIONS: These results suggest that TACE withEpiADM and SMANCS-Lipiodol will contribute to im­proved local control for HCC, but it should be limited tothe tumor-bearing segment or subsegment to avoid se­rious damage to the normal liver tissue.

Poster No. 224

Basic Examination of Sustained Release andEmbolization with Poly-L-Laetic Acid MicrospheresKazuhisa Fujiwara, MD, PhD, Kyoto-shi, japan.

Yasushi Nagata, MD. Masahiro Hiraoka, MD. Norio

Araki, MD

PURPOSE: To examine the usefulness of poly-i-lacticacid microspheres (PLA) for chemoembolization, a basicinvestigation of the sustained actions and embolizingeffects of PLA using white rabbits was performed.

METHODS: Sustained release of an embolizing materialwas accomplished with 1 mg of PLA containing 0.03 mgof epirubicin hydrocWoride (EPI). The renal artery ofrabbits was embolized with 50 mg of PLA (Chemo-TAEgroup). Venous blood was collected before and afterembolization. Blood EPI levels were measured. The kid­ney was isolated from rabbits killed 24 hours after em­bolization to measure tissue EPI levels and to macro­scopically and histologically examine the kidney. Agroup in which 1.5 mg of EPI alone was injected throughthe renal artery was established as a control group (TAlgroup).

RESULTS: The blood EPI level in the TAl group rapidlyreached a peak within 30 minutes after injection. How­ever, in the Chemo-TAE group, the blood EPI levelremained at a low level until 24 hours after embolization.In the Chemo-TAE group, EPI levels in the kidney tissueisolated 24 hours after embolization were significantly

higher than in the TAl group. When isolated kidneyswere macroscopically and histologically examined, atro­phy of the entire embolized kidney and infarction andnecrosis in the renal cortex were observed in the Chemo­TAE group. However, there were no histologic findings

in the TAl group.

CONCLUSION It was demonstrated that EPI-PLA, a che­moembolizing material, maintained high local concen­trations of the anticancer drug while maintaining lowblood levels of the anticancer drug.

Poster No. 225

Feasibility Study for the Use of Agarose as aMethod of Modeling the AnchoringCharacteristics of Lung Tissue for theDevelopment of an Endovascular Coil-BasedVideo-Assisted Thoracoscopic Surgery RetrievablePulmonary Nodule Localization DeviceLawrence M. Casa, MD, West Point, NY. john

Reinschmidt, MD. Sean Murray, MD. Mj. DeHart.

jim Wright. jeffrey A. Yngstrom, MD, et al

PURPOSE: To determine if agarose has similar anchoringcharacteristics as lung tissue. This would allow visualiza­tion of pulmonary localization devices during displace­ment.

MATERIALS AND METHODS: Three harvested goat lungswere injected with hook-wires and helical coils attachedto suture. The hook-wire and coils were injected at threedifferent depths, 1, 2, and 3 em. The lung was then takento an Instron 8500 to measure the force required todisplace these devices from lung tissue. The Instron 8500plotted out displacement curves characteristic for lungtissue. The hook-wires and coils were then injected intovarious concentrations of agarose. Displacement curveswere generated using the agarose model. The curves inlung and agarose were then compared.

RESULTS: A 4% concentration of agarose generated sim­ilar displacement curves as ex vivo goat lung. The mag­nitude of the force displacing a coil or hook-wire fromagarose was less than that of ex vivo goat lung (0.155 Ibvs. 0.29 Ib for coils, and 0.32 lb vs. 0.75 lb for hook­wires).

CONCLUSION Agarose is an excellent model for study­ing the anchoring characteristics of devices in lung tis­sue. Its transparency allows visualization of the devicesduring displacement. This can provide insight into theanchoring characteristics of current and future devicesembedded into lung tissue.

Poster No. 226

CT-Guided Transthoracic Needle Biopsy Using anIpsilateral Decubitus PositionAlia M. Rozenblit, MD, Bronx, NY. Arlene M. Klink,

MD • joseph Tuvia, MD

PURPOSE: To determine the utility of an ipsilateral de­cubitus position (lLDP) for CT-guided transthoracic nee­dle biopsy (TfNB) of lung and mediastinal masses.

METHODS: Nineteen patients with 13 lung and 6 medi­astinal lesions had CT-guided TfNB performed in anIiDP. The lesions had a mean diameter of 2.7 em (range0.8-7.0 em) and a mean distance from either anterior or

posterior pleura of 1.1 em (range 0-5.0 em). All patientshad fine-needle aspiration biopsies (FNAB). Two pa­tients with nondiagnostic FNAB had automated needlecore biopsy. From one to five needle passes were made(mean 2.4 passes), with a mean of two passes traversingthe pleura (range, 0-5).

RESULTS: Specific cytologic or histologic material wasobtained in 17/19 (89%), including all mediastinal le­sions (100%) and 11/13 lung lesions (84%). Of 17 diag­nostic specimens, there were 15 (88%) malignant and 202%) benign lesions. The two patients with nonspecificFNABs had stable-appearing lesions on 18-month and24-month follow-up CT studies and are presumed be­nign. Postbiopsy pneumothorax not requiring treatmentoccurred in two patients 00.5%). By using an ILDP,traversing the pleura was avoided in three of the sixmediastinal masses.

CONCLUSION TINB in an ILDP can be successfully usedfor selected lung and mediastinal lesions with good re­sults and a low pneumothorax rate. The latter is likelydue to decreased lung mobility as well as to the im­proved extrapleural window for mediastinal biopsies.

Poster No. 227

Creation of Portal Vein Thrombosis and PortalHypertension with Polyacrylonitrile TranshepaticPortal Embolization: An Animal ModelMoni Stein, MD, Sacramento, CA. Daniel P. Link, MD

PURPOSE: To create portal vein thrombosis and portalhypertension in pigs via transhepatic polyacrylonitrile(PAN) embolization.

MATERIALS AND MElHODS: Transhepatic portal accesswas created in six pigs (mean weight 17.1 ::'::: 1.7 kg)using a 6.5F catheter system. Portal embolization wasperformed with liquid PAN preparation until cessation offlow. The pigs were followed weekly with transhepaticportal venography and were re-embolized when portalrecanalization occurred. The study endpoint for each pigwas demonstration of complete portal thrombosis 1week following the previous embolization. Portal pres­sures were measured before and after each emboliza­tion. Blood liver function tests and ammonia were drawnat each session. Histopathology was performed to ana­lyze the effect of embolization on the portal vein walland liver architecture.

RESULTS: Portal vein thrombosis was achieved in all pigsafter a mean of 2.2 ::'::: 0.4 sessions and a mean volume of12.4 ::'::: 3.4 cc of PAN. The mean pre-embolization portalpressure of 7.3 ::'::: 1.9 mmHg was elevated acutely to amean of 28.7 ::'::: 6.5 mmHg following embolization. Themean portal pressure after demonstration of chronic por­tal thrombosis was 12.4 ::'::: 2.3 mmHg. All pigs developedcavernous transformation of the portal vein and exten­sive spontaneous portosystemic collaterals. The only ab­normal blood test was ammonia (mean 149 ::'::: 95.3).Histopathology demonstrated mild inflammation and

foreign body reaction of the portal vein wall with relativepreservation of the wall layers. The embolization withPAN created a cast of the entire portal system withextension into the intrahepatic portal veins. The liverarchitecture was well maintained.

CONCLUSION Portal vein thrombosis was successfullycreated with transhepatic PAN embolization. Portal pres­sure was only mildly elevated due to cavernous trans­formation and spontaneous portosystemic collaterals.

Poster No. 228

Regeneration of the Liver Parenchyma FollowingPortal Vein Embolization: Long-Term Follow-UpAtsuhiro Nakatsuka, MD, Tsu, Japan. KoichiroYamakado, MD • Naoshi Tanaka, MD. TadanoriHirano, MD • Kaname Matsumura, MD • Kan

Takeda, MD

PURPOSE: Portal vein embolization (PYE) induces atro­phy of the embolized hepatic parenchyma and hyper­trophy of the unembolized liver. However, there hasbeen no study evaluating a long-term change in livervolume follOWing PYE. The purpose of this study was toevaluate a long-term change in the volumes of emboli­zed and unembolized liver parenchyma.

MATERIALS AND METHODS: Five patients were studied.Four patients had hepatocellular carcinoma and onepatient had bile duct cancer. PYE was performed in theright portal vein with ethanol after percutaneous trans­hepatic portography. Volumes of the embolized andunembolized liver parenchyma were measured withcomputed tomography before and 1 (n = 5), 3 (n = 5),6 (n = 3), and 12 months (n = 3) after PYE.

RESULTS: Hypertrophy of the unembolized liver contin­ued until 3 months after PYE. The mean increase in theunembolized liver volume was 61.1 ::'::: 23.8% after 1month, 97.2 ::'::: 42.9% after 3 months, 94.9 ::'::: 20.2% after6 months, and 92.3 ::'::: 38.7% after 12 months. Atrophy ofthe embolized liver continued >3 months. The meandecrease in the embolized liver was 29.3 ::'::: 32.8% after 1month, 32.1 ::'::: 17.7% after 3 months, 65.1 ::'::: 20.3% after6 months, and 75.0 ::'::: 14.0% after 12 months.

CONCLUSION Hypertrophy of the unembolized liverparenchyma continues until 3 months, and atrophy ofthe embolized liver continues >3 months after PYE.

Poster No. 229

Percutaneous Gastrostomy in the Neonate:Comparison of a New Technique with theAntegrade MethodAnne M. Cahill, ME, FRCR, FFR.RCSl, Pittsburgh, PA.Robin D. Kaye, MD. Charles R. Fitz, MD. Richard B.

Towbin, MD

PURPOSE: To compare the efficacy of the standard an­tegrade (pull) method to a newly developed "push-pull"technique in small patients less than 1 year of age.

295

296

.MATERlALS AND MElliODS: Over a 4-year period0994-1998), 32 patients had insertion of percutaneousgastrostomy tubes (PGTs) using the "push-pull" method.There were 20 boys and 12 girls with a mean age of 4.5months (range 0.44-9.13) and a mean weight of 4.2 kg(range 2.3-7). This group was compared retrospectivelyto a group of 32 patients matched for age, weight, andsex who had PGT insertion using the antegrade tech­nique. The charts were retrospectively reviewed for bothgroups to determine efficacy and complication rates.

RESULTS: Tubes were successfully placed in 97% ofcases using the "push-pull" technique and in 88% usingantegrade technique. There was one failed tube insertionin the "push-pull" group due to failed sedation and fourfailures in the antegrade group because of an excessiveesophageal diameter at the level of the cricopharyngeus.Four of these cases had successful PGT placement withimmediate change to the "push-pull" technique. Earlycomplications were seen in 9% of patients in the "push­pull" group: gastrocolic fistula (n = 1) and tube dis­lodgement (n = 2). There were no early complications inthe antegrade group. There were no late complicationsidentified in the "push-pull" group. There was one latecomplication (gastrocolic fistula) in the antegrade group.

CONCLUSION The "push-pull" technique is an excellentnew technique for the insertion of PGTs in the neonatalsetting. This technique compared favorably with the an­tegrade method in outcome in our patient group.

Poster No. 230

Correlation Between the Portal PressureDifference and the Morphologic Change of theGastroesophageal Varices on EndoscopicExamination Mter TIPSHyunWoong Shin, MD, Taegu, Korea. TaeBeom Shin,MD. HungKyu Ryeom, MD. Yong/oo Kim, MD

PURPOSE: To study the correlation between the portalpressure difference and the morphologic change of thegastroesophageal varices on endoscopic examination af­ter TIPS.

MA TERlALS AND MElliODS: Sixty-four patients who un­derwent endoscopic examination before and after theTIPS procedure were included in this study. We classi­fied varices as either esophageal or gastric according tothe location. In total, 114 cases were evaluated (esoph­ageal varix, 54 cases; gastric varix, 60 cases). The TIPSprocedure was done in 70 cases and TIPS combined withcoil embolization of the variceal vein was done in 44cases. Morphologic change of the gastroesophageal var­ices was classified into three groups: complete disap­pearance, partial disappearance, and no change. Statis­tical correlation was evaluated using ANOVA betweenpre- and postprocedural portal pressure difference ineach group.

RESULTS: Among 54 cases of esophageal varices, com­plete disappearance occurred in 12 cases (22%) and

partial in 33 (61%); there was no change in 9 07%).Among 60 cases of gastric varices, complete disappear­ance occurred in 20 cases (33%) and partial in 33(55%);there was no change in 7 (12%). Of the 70 cases under­going TIPS, the average portal pressure difference beforeand after the procedure was 11.3 mmHg (n = 23) incomplete disappearance, 9.8 mmHg (n = 38) in partialdisappearance, and 6.89 mmHg (n = 9) in no changepatients. A significant statistical difference was foundbetween morphologic change and average portal pres­sure difference at each group (p = 0.0088). Of the 44cases undergoing the combined procedure, the averageportal pressure difference was 8.0 mmHg (n = 8), 7.7mmHg (n = 29), and 8.6 mmHg (n = 7), respectively. Nostatistical difference was seen between each group (p >0.05).

CONCLUSION Endoscopic improvement was more com­mon in gastric than in esophageal varices, but no statis­tical significance was found. A significant statistical cor­relation was found between endoscopic change andportal pressure difference in TIPS, whereas no statisticalcorrelation was seen in cases with combined therapy.

Poster No. 231

Assessment of Effect of Hepatic Blood Flow onCoagulation Size of Microwave Tissue CoagulationTherapy: An Experimental StudyManabu Takamura, MD, Suita-city, Japan.Takamichi Murakami, MD, PhD. Takashi Shibata,

MD, PhD. Takeshi Ishida, MD, PhD. Tadayuki Sato,MD, PhD. Hironobu Nakamura, MD, PhD

PURPOSE: To evaluate the cooling effects of hepaticblood flow on the coagulation size of microwave tissuecoagulation therapy (MTC).

MATERIALS AND MElliODS: Laparotomic MTC was per­formed in three Landrace pigs under general anesthesia.Vascular tapes were put on the hepatic artelY and portalvein in Glisson's sheath. We selected 24 points in thelivers of the pigs, and then randomly separated them intofour groups. MTC was performed without stopping thehepatic blood flow (N group), with clamping the hepaticartery by a vascular tape (A g~oup), with clamping theportal vein (P group), or with clamping both the hepaticartery and the portal vein (AP group). MTC was per­formed at 60 watts for 60 seconds with an electrodeneedle 1.6 mm in diameter, which was used for percu­taneous MTC. After MTC, livers were removed and thediameter of the coagulation area in each group wasstatistically compared with the Mann-Whitney U test.

RESULTS: The diameter of the coagulation area was9.67 ± 1.37 mm in the N group, 12.00 ± 1.41 mm in theA group, 17.17 ± 1.72 mm in the P group, and 17.83 ±1.73 mm in the AP group. The diameters of the coagu­lation area of the P and AP groups were statisticallylarger than those of the other groups (p < 0.05). Therewas no significant difference in the diameter of thecoagulation area between the P group and the AP group.

CONCLUSION The diameter of the coagulation area ofMTC depends mainly on the portal venous flow, while itincreased by stopping the hepatic blood flow.

Poste.r No. 232

Ureteral Occlusion with Hydrogel and CoilsDaniel P. Link, MD, Sacramento, CA • Moni Stein,

MD. Bennett j. Kashdan, MD. Paul D. Kamin, MD.

j. Mark McKinney, MD

PURPOSE: To describe a new method of ureteral occlu­sion for treating urine leakage associated with advancedpelvic malignancy.

METHODS: Six patients with complications of urine leak­age were treated by intraureteral injection of 2 to 5 ml of5% polyacrylonitrite (PAJ'I) by volume in MSO and vas­cular occlusion coils. Patients were followed clinically;leaks documented by nephrostogram were reinjected.

RESULTS: Eight ureters in six patients were occludedusing these methods. All patients were satisfactorilytreated and their condition requiring embolization re­solved (average follow-up 7 months). The coils acted asa foundation for the soft, solid PAN plug. Although therewas an immediate ureteral blockade, two patients re­quired a second injection after 1 and 2 months. Onepatient had some antegrade flow but went to occlusionin a few weeks. The hydrogel mass may have beencolonized with Candida albicans.

CONCLUSION Occlusion of the ureter with coils andhydrogel is effective for treating urinary leakage for pal­liation of this difficult medical problem. PAN should notbe used at this time for patients expected to have long­term survival.

Poster No. 233

Percutaneous Treatment of EmphysematousPyelonephritis Complicated with AbscessFonnation in Uncontrolled Diabetic Patientsjae-[(yu Kim, MD, PhD, Kwangju, Korea. Yang-Yean

jeong, MD, PhD. Heoung-Keun Kang, MD, PhD.

Bong- Yeol Oh, MD, PhD. Byung-Suk Roh, MD, PhD

PURPOSE: To evaluate the effectiveness of percutaneousabscess drainage for the treatment of emphysematouspyelonephritis in uncontrolled diabetic patients.

MA TERIALS AND METHODS: Ten cases of nine uncon­trolled diabetic patients with emphysematous pyelone­phritis with abscess were treated with percutaneousabscess drainage. Procedures were done under fluoro­scopic gUidance in nine cases and under US guidance inone case. The results were classified as complete suc­cess, partial success, or failure.

RESULTS: Eight cases were considered complete suc­cesses; one case was considered a partial success. Onecase, which had diffuse renal parenchymal destructionwithout perirenal fluid collection, was considered a fail­ure. The duration of drainage ranged from 10 to 45 days

(mean 23 days). Bacteremia occurred in one case; it wastreated with antibiotics for 2 days.

CONCLUSION In uncontrolled diabetic patients, percu­taneous abscess drainage is a safe and effective thera­peutic method in emphysematous pyelonephritis withabscess and no diffuse parenchymal involvement.

Poster No. 234

Preoperative Transcatheter Arterial InfusionChemotherapy for Advanced Breast CancerKakuya Kitagawa, MD, Tsu, japan. Koichiro

Yamakado, MD. Atsuhiro Nakatsuka, MD. Kaname

Matsumura, MD. Yoshifumi Kawarada, MD. Kan

Takeda, MD

PURPOSE: Despite the recent advances in combinedtherapies, the prognosis of patients with advanced breastcancer is poor. The purpose of this study was to evaluatethe clinical utility of preoperative transcatheter arterialinfusion chemotherapy (TAlC) for advanced breast can­cer.

MA TERIALS AND METHODS: Seven patients with ad­vanced breast cancer (stage Ill) underwent preoperativeTAle. The maximum tumor size was 4 cm or >4 cm(4.0-12.5 cm). TAlC was performed one to four times(mean 1.9 times per patient) before mastectomy. Anti­cancer drugs (doxorubicin, 5-fluorouracil, and mitomy­cin C) were injected in the internal thoracic and/or sub­clavian artery. The mean duration between TAlC andmastectomy was 33 days (9-60 days).

RESULTS: TAlC was successfully performed withoutcomplications in all patients. The maximum tumor sizesignificantly decreased from 8.3 ± 3.7 cm to 5.1 ± 2.7 cmbefore mastectomy (p < 0.05). Downstaging wasachieved in two patients (28%). Systemic chemotherapy(n = 5) and radiation therapy (n = 2) were added aftermastectomy. One patient died of lung and liver metas­tases 7 months after mastectomy. The other six patientsare still living (7-41 months). The 3-year survival ratewas 83%.

CONCLUSION Preoperative TAlC is a feasible and safetreatment. It has a strong anticancer effect and can be oneof the combined therapies for advanced breast cancer.

Poster No. 235

A New Material to Induce the Local Fonnation ofGranulation Tissue: PDGF-BB LoadedBiodegradable PolymerGunnar B. Lund, MD, Baltimore, MD. F. Nicholas

Franano, MD • Hai-Quan Mao, PhD. Wei-Ping Lee,

PhD. Carolyn Magee, MS. john Strandberg, DVM,

PhD, et al

PURPOSE: To develop a new material that induces thelocal formation of granulation tissue in a controlled andpredictable manner.

MA TERIALS AND METHODS: The isoform BB of platelet­derived growth factor (PDGF) is a small protein that

297

298

stimulates the formation of granulation tissue. A humanrecombinant form of PDGF-BB was incorporated into atough, flexible, biodegradable polyphosphoester poly­mer film matrix, P(BHET-EOP/TC, 80/20), using a cryo­evaporation method. Maltose was coloaded with thePDGF-BB to enhance protein release. 10 X 10 X 2-mmsquares of both PDGF-BB polymer film and empty poly­mer were implanted in the subcutaneous tissue of thethigh of New Zealand White rabbits. After 2 weeks, theremaining polymer and the adjacent tissues were excisedand analyzed histologically.

RESULTS: The PDGF-BB loading level was 0.01% to 0.1%by weight. Each small square contained approximately165 ug of PDGF-BB. Five days after implantation, therewas subjective warmth, erythema, and local soft tissuesweJling at the PDGF-BB polymer site that was notpresent at the empty polymer site. Histologic analysis ofthe excised PDGF-BB polymer site demonstrated thelocal formation of a thick wall of well-vascularized fi­brous connective tissue in vivo, composed mostly offibroblasts in an areolar matrix and endothelial cells.Conversely, the empty polymer site demonstrated a thinwall of more mature connective tissue. Some inflamma­tory cells, including eosinophils, were attracted to boththe PDGF-BB polymer and the empty polymer site.

CONCLUSION A simple and versatile method of deliv­ering a sustained local dose of PDGF-BB to a specific sitehas been developed using polymer drug delivery meth­ods. The PDGF-BB polymer induces the local formationof granulation tissue in vivo. Potential clinical uses in­clude closure of fistula tracts and modification of fibroustissue and smooth muscle responses to vessel injury.

Poster No. 236

Percutaneous Ethanol Injection forHepatocellular Carcinoma in the Caudate LobeToshiya Shibata, MD, Kyoto, japan. Yoji Maetani, MD.

Fumie Ametani, MD. Kyo !toh, MD. junji Konishi, MD

PURPOSE: Hepatocellular carcinoma (HCC) originatingin the caudate lobe is rare, and surgical resection ortranscatheter arterial chemoembolization (TACE) forcaudate HCC is thought difficult because of the uniquelocation between the hepatic hilum and the inferior venacava or because of the complexity of the arterial bloodsupply. Percutaneous ethanol injection (PEI) is an effec­tive treatment for ablation of HCC, but PEl for caudateHCC has not been reported. The purpose of this studywas to evaluate the efficacy of PEl for caudate HCC.

MATERIALS AND METHODS: PEl was performed for 11caudate HCCs in 11 patients. The technical results, ther­apeutic response of PEl, and survival rates of the 11patients were evaluated.

RESULTS: A total of 30 sessions of PEl were successfullycarried out. Abdominal pain and fever were noticed ineight and seven sessions respectively, but no severecomplications, defined as peritoneal hemorrhage, tumorseeding, or thrombus in portal vein or inferior vena cava,

were encountered. At dynamic CT after PEl, intratumoralenhanced lesion was not seen in 10 HCCs. During fol­low-up 06-45 months), no local recurrence was no­ticed in nine patients, and two patients had local recur­rence. The local recurrence was treated with PEl again inone patient. Seven patients had new lesions in the otherparts of the liver that were treated with PEl and/or TACE.Two patients died of multiple HCCs, and one patient diedof rupture of esophageal varix. The 1-, 2-, and 3-yearsurvival rates were 82%, 72%, and 72%, respectively.

CONCLUSION PEl proved to be safe and effective forcaudate HCCs. PEl will improve the long-term prognosisof patients with caudate HCC.

Vascular DiagnosisPoster No. 237

Intravascular Ultrasound Assessment of ThoracicAortic Traumajon D. Hom, MD, Charleston, SC. Renan P. Uflacker,MD • Bayne Selby, MD

PURPOSE: To present the use of the modality of intra­vascular ultrasound (NUS) in the assessment of thoracicaortic trauma.

MATERIALS AND METHODS: Seventeen patients withclinical suspicion of traumatic lesions of the thoracicaorta related to rapid deceleration were included thestudy. NUS was performed with a 6F, l2.s-Mhz cathetertransducer in all patients following DSA thoracic arterio­grams. The ultrasound examination was recorded onvideocassette. Spiral CT scans were performed in fivepatients before arteriography. Each case was reviewedby two interventional radiologists.

RESULTS: Of the 17 patients, 4 had aortic or great vesselinjury confirmed at surgery. Six patients were found tohave positive IVUS findings, while DSA was positive infive cases. A false positive in both modalities was a ductusdiverticulum. One false negative on DSA was present,with lVUS finding an intramural aortic hematoma.

CONCLUSION Our initial experience with lVUS for theevaluation of aortic and great vessel trauma shows thepromise of this modality in increasing the sensitivity ofdetection. Pseudoaneurysm formation, intimal flaps, andintramural injury were readily identified with lVUS. In­tramural hematoma with pseudoaneurysm was not de­tected by DSA and was seen only with lVUS. An atypicalductus diverticulum was misinterpreted as trauma inboth DSA and lVUS. lVUS as an adjunctive tool in theassessment of thoracic aortic injury has the potential forincreasing the sensitivity of DSA alone.

Poster No. 238

MR Angiography of Vena Cava Filters: An In VitroStudyMinont Honda, MD, Yokohama, japan. MasaoObuchi, MD. Kenji Takizawa, MD. Shin Matsuoka,

MD. Yoshio Kuniyasu, MD • Hirotsugu Munechika,

MD, et al