MATERIALS AND METHODS: FoIlowing IRB approval theOmnisonics Resolution 360 wire was used in six patientswith lower extremity ischaemia and occlusion of the femoralartery. The type of vascular occlusion varied from acute ( 3weeks) to chronic (IS years) and from short (6cm) to long(40cm) lesions. Device activation time varied from 6 minutesto 10 minutes.

RESULTS: The ultrasound energy produced by activation ofthe Omnisonics Resolution 360 wire appears to be safe withinthe femoral artery. It is most effective with recent thrombusbut is also capable of producing a channel in older thromboticocclusions. The device was not affected by the presence offemoral stents (Wallstent and Symphony sten ts, BostonScientific*) and activation in a subintimal location did notresult in damage or rupture of the vessel being treated. In oldocclusions adjunctive angioplasty is required to provide asuitable luminal diameter. Removal of the handle from thewire allows it to be used for rapid-exchange balloon insertion.The wire can be used across the aortic bifurcation and the tipcan be shaped and rotated to provide greater coverage.Although there was significant opportunity for embolisationof thrombus or plaque in these heavily diseased vessels, thiswas seen only once in 6 cases and occurred after subsequentbaIloon z.ngioplasty.

CONCLUSION: The wire appears to be effective and safe atthe available energy levels.

Vascular Interventions: Liver

Poster No. 329

Anastomotic Stenoses in Children Liver Transplant:Results, Complications and Follow-Up of PercutaneousTreatment.R. Nani, Istituto di Radiologia OORR Bergamo, Bergamo,Italy, - R. Agazzi

PURPOSE: Anastomotic stenosis is a frequent complicationin children liver transplant, especially in split liver transplant(13-30%). Transhepatic percutaneus cholangiography (PTC)and bilioplasty are major tools in evaluation and treatment ofanastomotic bili ary stricture. In this paper we report technicalsuccess, complications and follow up in patients managedwirh bilioplasty.

MATERlALS AND METHODS: From 1997 to June 2002 inthe Liver Transplant Center of our hospital were performed179 liver transplant in 161 children (average age: 1,4 year;average weight: 10Kg). Anastomotic stenoses occurred in 27patients and were managed percutaneously.

RESULTS: We performed 36 PTC in 27 children. PTC waspossible in all patients, event without dilatation of biliaryducts. Bilioplasty was successfull in 80% (28/36 attempts).Complications occurred in 13%, with just one majorcomplication (hemopeIitoneum). Eight recurrences (33%)occurred in successfully treated patiems during a 3-44 monthsfollow up period and required a new bilioplasty treatment.

CONCLUSION: Interventional radiology plays a major rolein the correct treatment of biliary complications afterorthotopic liver transplantation in children, even in split liversor reduced livers. PTC and bilioplasty are successful in a highpercentage of patients. Restenoses are frequent, but a newpercutaneus treatrnent is possible.

Poster No. 330

Endovascular Treatment of Vascular AbnormalitiesFollowing Liver Transplantation.T.R. Alfuhaid, Toronto Genera' Hospital, Toronto, ON,Canada - J.R. Kachura - K. W Sniderman

PURPOSE: To evaluate the efficacy ofendovascular treatmentof vascular abnormalities following orthotopic livertransplantation (OLT).

MATERlALS AND METHODS: From June 1997 to September2002, 10 procedures were peIformed in 7 patients diagnosedwith vascular complications of OLT on the basis of clinicalpresemation, serum biochemistry, and Doppler ultrasoundand/or CT examinations. 4 patients presented with hepaticartery (HA) anastomotic stenoses, one patient had HAthrombosis, one patient had inferior vena cava and cava-hepaticvein anastomotic stenoses, and one patient had both HA andportal vein anastomotic stenoses. Mean follow-up was 21months (range 3 months-S years).

RESULTS: The mean time interval between most recent OLTand endovascillar treatment was 3 months (range 22 days-6months). Ofthe S HA anastornotic stenoses, 2 were primarilystented: there was re-stenosis by Doppler ultrasound of onelesion at 7 months, whereas the other required placement of astent-graft because ofextravasation post-stenting and remainspatent at 10 months follow-up. Of the other 3 HA stenoses:one had recurrent stenosis at 3 months post-PTA, thendissection at the second intervention requiring stenting, andwas noted to be occluded 4 months after stenting althoughgraft function remains good at S years; the second hadhemodynamically significant dissection at attempted PTAand the tortuous true lumen could not be accessed but graftfunction is good at 4 years; and the third had dissection andHA thrombosis post-PTA of the tortuous vessel, and repeatOLT was peIfonned 7 months later. The patient who presentedwith HA thrombosis had initial resolution of thrombus after12 hours of fibrinolysis, revealing a complex dissection;although PTA was performed, stenting was not technicaIlypossible because of vessel tortuosity and rethrombosisoccurred necessitating repeat OLT 4 days later. The venousanastomotic stenoses were treated with PTA successfullyand remain patent at 3 and 9 months foIlow-up.

CONCLUSION: Although PTA may be feasible and effectivefor the treatrnent of liver transplant venous abnorrna1ities,PTA of HA anastomotic stenoses is often complicated bydissection and thrombosis, with vessel tortuosity acontributing factor.

Poster No. 331

Inhibition of Pseudointimal Hyperplasia in Swine TIPSModel: The Efficacy of Local Delivery of PaclitaxeI.S. W Park, Korea university Guro hospital, Guro-dongGuro-gu, Seoul, Korea -I.H. Cha - S.H. Lee - K.A. Kim ­C.M. Park - c.H. Kim

PURPOSE: To investigate the efficacy and feasibility oflocaldelivery of paclitaxel to inhibit pseudointimal hyperplasia inswine TIPS models.

MATERIALS AND METHODS: TIPS were created in 7healthy domestic swine (IS-20kg). Before TIPS stentinsertion, short term infusion of paclitaxel into TIPS tractusing balloon catheter (4cm-long, 8mm-diameter) in whichtwo O.OlO-inch holes were created on opposite sides of theballoon in 4 anirnals. Instead of paclitaxel, short term infusionof saline was underwent in 3 control animals. Paclitaxel orsaline was received in all animals to hepatic parenchymal and 5113

S114

venous outflow lract. Atotal of 30ml paclitaxel (70/lmoUL)or saline was infused through the balloon while pressure wasmaintained between 4 and 6 atm. The animals were folIowedfor up to 2 weeks and were sacrificed. The specimen wereplaced in 10% formalin before the shunts and stents werecarefully bisected in a longitudinal fashion. Gross andhistologic evaluations of the shunts were performed.Pseudointimal hyperp1asia was determined between lumenand hepatic parenchyma, and maximum pseudointimalhyperp1asia thickness were calculated for each animals.

RESULTS: The average infusion time of paclitaxel or salinewas 7.6 min (6-9min). At gross and histologic evaluation,considerable pseudointima1 hyperplasia had formed andstatistical1y significant differences was found in the maximumpseudointimal hyperplasia thickness between control(2.41 mm±O.74 mm) and paclitaxel recei ved animals(0.67rnm±O.22mm, p<0.05).

CONCLUSlON: Local delivery of paclitaxel at the time ofTIPS creation is effective for reducing pseudointimalhyperplasia in swine TIPS model.

Poster No. 332

Nitinol Stents for TIPS.SL Wang, Stanford University Medical Center;Dept.Radiology, Stanford, CA, USA • M.D. Dake • M.K.Razavi • S. T. W Kee • l.K. Frisoli • D. Y. Sze

PURPOSE: To investigate potential advantages ofusing self­expanding nitinol (SMART) stents in de novo creation oflransjugular intrahepatic portosystemic shunts (TIPS).

MATERlALS AND METHODS: We performed a retrospectivereview of TIPS performed at our institution from March 1999to February 2002. During this period, SMART stents wereselected for placement in TIPS procedures in 21 patients(53+ 12 years old). Indications were varied with the mostcommon being variceal bleeding (n=11), recurrent ascites (n=4),or both (n=l). De novo TIPS stents were placed in 18 patientswhile 3 patients received parallel stents for occluded primaryTIPS. Primary and secondary patency wece determined onfollow-up with ultrasound, angiography, CT, MRI, and/orpathological specimens in transplanted patients.

RESULTS: Technical success was achieved in creating TIPSin all patients. Mean time to follow-up was 289 days (range1-952 days). At the time of this writing, six patients requiredangioplasty or shunt revision. One patient was revised a secondtime. For patients requiring revision or pIasty, mean time tointervention was 120 days. Reasons for revisions included:variceal bleeding (n=l), restenosis of the stent by imagingcriteria (n=3), and recurrent ascites (n=2). Three patientsunderwent Iiver lransplant. Overall six month mortality andone year mortality rates were 38%, and 43% respectively.One month, six month, and one year patency rates for survivingpatients were 93%, 64%, and 50% respectively.

CONCLUSlON: The mortality and patency rates of SMARTstent-created TfPS are within the published range of valuesfor conventional Wallstent-created TIPS. These resultsdemonslrate the feasibility of SMART stents in creating TIPS.Potential differences in stent performance involvingbiocompatibility, radial strength, conformability, lack ofshortening, and celi size did not appear to lend an overalladvantage for patency.

Poster No. 333

Utilizing the MELD Score as a Predictor of Early Deathsin Patients Undergoing Elective TIPS Procedures.A.B. Montgomery, University ofTexas Health SciencesCenter at San, San Antonio, TX., USA • WL. Dobie,Jr. • H.Ferral

PURPOSE: To evaluate the MELD score as a predictor ofearly death (within 30 days) in patients undergoing electiveTIPS.

MATERIALS AND METHODS: The medical records of allpatients who underwent a TIPS procedure between May l,1999 and June 1,2002 were reviewed. Patients who underwentelective TIPS were selected and patients who had early death(ED) after TIPS were studied. The MELD before TfPS, 24hours after TIPS, and closest to death was calculated. Etiologyof cirrhosis, operators, procedure time, proceduraIcomplications, intubation time, lransfusion requirements,CBC, liver function panel and blood cultures were recorded.85 patients underwent an elective TIPS. 11 patients with anED post TIPS were identified. A control group was thencreated by randomly selecting 15 patients from the group of74 who survived more than 30 days after TIPS. In this group,the pre-TIPS, 24 hr post-TIPS, and data obtained l monthafter TIPS was used for the comparison. Data were ana1yzedusing independent sample t-test.

RESULTS: In comparing the ED population to the survivingpopulation, the pre-TIPS MELD was 17 and 14 respectively(P>0.05); the 24 hr post-TIPS MELD was 23 and 17respectively. At 24 hr post-TIPS, the mean change in MELDwas 5 and 3 respectively (P=0.09). The mean MELD nearestto the time of death was 30 for the ED group and 17 forsurvivors. The mean MELD difference was 13 (P=0.0019).No differences in any other variabIes were identified. Factorsconlributing to the change in the MELD were evaluated. TheED group had a mean increase of 2.1 mg/dL in total bilirubinlevels 24 hr after TIPS, wbile survivors had a mean increase oflA mg/dL (P=OA34). The ED group had a mean increase of12.1 mg/dL in total bilirubin levels at the time of deathcompared to a mean increase of 2.2 mg/dL in survivors(P=0.OO9). No significant differences were found in serumcreatinine or !NR levels.

CONCLUSlON: The pre-TIPS MELD does not appear to bea predictor of early death after elective TIPS in our patientpopulation. There is a progressive, significant increase in theMELD in patients with early death as compared to survivors.The increase in the MELD was related to a progressive increasein total bilirubin levels.

Poster No. 334

Trans Hepatic Portal Vein Puncture in Islet CelITransplantation; Should the Tract Be Embolized.R.J. Owen, University ofAlberta Hospital, Edmonton, AB,Canada • D.M. McNally • E.A. Ryan • T. Ackerman • l.Shapiro

PURPOSE: Portal vein (PV) access for islet infusion carries arisk of hemorrhage from the trans hepatic lract and of PVthrombosis following islet infusion. We will discuss therelationships between catheter size, embolization andhemorrhage risk.

MATERIALSANDMETHODS: Since March 1999thirty sevenpatients with type l diabetes had atotal of 76 PV accessprocedures for pancreatic islet cell infusions. Patient charts,proceduraI records and post-procedure abdominal imaging werereviewed.

RESULTS: Successful islet infusion was achieved in allprocedures and fuli results were available in 74176. Fourpatients suffered clinically significant hemorrhage, twodeveloped PV branch thrombosis and four had clinical evidenceof biliary puncture. Mean Hemoglobin (Hb) measurementsprior to the procedure were 129 gil and post 118 gil. Ultrasoundwas nonual/trace free fluid in57 (l0.4 gil), demonstrated biliarypuncture in 7 (10.4 gil), moderate free fluid in 9 (15.3 g/I),intrahepatic hematoma in 3 (10.7 g/I), gross intra-abdominalfluid in 2 (22 g/l) and portal vein branch thrombosis in 2 (6.5gil): [Figures in parentheses represent mean drop in /hb foreach category following the procedure). Using a 7 Freochintroduction system, mean drop in /Hb was 13.2 gil (withouttract embolization 14.5 g/I (0=4), with embolization 12.0 gil(n=30). Using a 4 French system Hb drop was 10.4 gil (withoutembolization by 11.6 gil (n=34), with embolization by 0.3 g/I (n=6).

CONCLUSION: Following percutaneous catheterization ofthe portal vein for islet celi infusion, decreased blood loss isassociated with smaller diameter PV access catheters and canbe reduced further (irrespective of catheter diameter) byemboliz2tion of the tract with Gelfoam.

Vascular Interventions: VenousThrombectomy

Poster No. 335

Mechanical Thrombolytic Devices in Acute MassivePulmonary Embolism Revascularization.M. Morucci, S.Camillo Hosp., Rome, ftaly, e P. Agresti eS.Pieri e A.R. Todini e L. de Medici

PURPOSE: Massive acute Pulmonary Embolism (PE) is oftena fatal disease, and local directed low dose fibrinolytic therapy(LO-Ff) is spreading as the treatment of choise. Nonethelessin very serious pts, LO-Ff could not be sufficient to save ptslives. As thrombolytic devices (TO) have been developed inthe last years, our purpose has been to verify the feasibilityand the clinical outcomes of using such mechanical devices totreat these critical conditions.

MATERfALS AND METHODS: Between June 1999 - Sept2b02, 142 pts were treated by LO-FT, by means of low doseurokinase; (40.000 iu/h); 76/142 pts presented extreme massivePE, and a mechanical treatment by angiographic catheterfragmentation was performed in 61176 cases presentig veryhigh pulmonary artery mean pressure ( PAMP)(over 60 cmof water). TD were used to obtain thrombus fragmentation in21/61 cases: 13/21ptd, 5//21 oasis, 3/21 rotablator. Fibrinolysisby uk (150.000 - 300.000 iu/uk) was always used during thefragmentation. Low dose LD-FT was always delivered afterthe mechanical fragmentation (up to 48 hrs, m=18 hrs), inorder to obtain a complete lysis of the fragmented clots.

RESULTS: In 18121 pts it was possible to reach pulmonaryarteries with a TO. A good mechanical thrombus fragmentationby TO was obtained in 15118 cases, although, in 3/18 apreliminary treatment by LO-FT was necessary. Ali ptstreated by TO presented a transient increase of PAMP, up to15 cm of water, immediately subsequent the fragmentation.The LO-FT, always performed after the thrombusfragmentation, got a complete ciot Iysis in 17/17 pts, with astrong MPP reduction in 16117 pts. No major or minorcomplications related to the procedure occurred during/afterthe thrombus fragmentation.

CONCLUSfON: The use of the new mechanicalthrombectomy devices to improve thrombus fragmentationin acute massive PE is feasi ble, safe, reasonable fast, avoidingopen surgery or very high fibrinolytic drugs doses. Anyways,it is mandatory to associate a LO-FT for 24-48 hrs, in order toobtain a complete clot Iysis and PAMP nonualization, but bymeans of a shorter and lower fibrinolytic regimen.

Poster No. 336

Fulminant Pulmonary Embolism: PercutaneousMechanical Thrombectomy during CardiopulmonaryResuscitation.M. Fava, Hospital Clinico Universidad Catolica de Chile,Santiago, Chile e S. Loyola e DL Veruska

PURPOSE: To present our clinical experience usingPercutaneous Mechanical Thrombectomy (PMT) to trealfulminant Pulmonary Embolism (PE).

MATERfALS AND METHODS: Seven patients in circulatorycollapse (4 women, 3 men), mean age 56 yo (raoge 30-79 yo)with fulminant PE underwent PMT during cardiopulmonaryresuscitation. Four patients had contraindication tothrombolytic drugs (2 recent major surgery, l politraumatism,l recent postpartum). Ali the cases were taken to the angiosuite during resuscitalion maneuvers in order to confinu thediagnosis of massive PE and to perfonu PMT (4 cases withHydrolyser, Cordis, and 3 cases with Oasis, Boston Sci,thrombectomy devices). In the three cases with nocontraindication to thrombolytics, rt-PA was used after PMT(bolus, 10 mg; infusion, 10 mg/h during 4 h).

RESULTS: PMT was successful to restore the pulmonaryperfusion in 6 patients (85.7 %). One patient died during theresuscitation maneuvers and PMT. Another patient hadischemic brain darnage post cardiac arrest. The 6 survivingpatients were discharged within 30 days. The PMT time was16 + 7 min. Systolic Pulrnonary artery pressure decreasedfrom a mean of65.0 +10.2 mm Hg before PMT to 41.2 + 9.7mmHg immediately after thrombectomy ( p < 0.05) and to35.3 + mm Hg after rt-PA infusion (p=NS). There were nomajor complications related to the thrombectomy procedure.

CONCLUSION: PMT treatrnent of Fulmioant PulmonaryEmbolism is a good treatrnent option to revert the circulatorycollapse during Cardiopulmonary Resuscitation, allowingrestoration of the pulmonary circulation which results in arapid improvement of hemodynamics. It offers an efficientand safe alternative to surgical thrombectomy andpharmacological fibrinolysis.ln this smali series there is areduced mortality although a larger nurnber of patients is neededto confirm this.

Poster No. 337

Combined Mechanical and Pharmacologic Thrombolysisfor Ilio-Femoral Deep Venous Thrombosis.H. 8jarnason, Mayo Clinic, Rochester, MN, USA e E.A.Sabater e S. Misra e W Wang eJ. McPhail e A. W Stanson,et al.

PURPOSE: Oescribe two years experience with the use ofmechanical thrombectomy combined with pharmacologicthrombolysis at one institution. Procedura] and clinicaloutcomes.

MATERlALS AND METHODS: Retrospective review for allpalients treated for iliac and femoral vein deep vein thrombosiswhere mechanical thrombectomy was used. Length ofsymptoms, distribution of thrombosis, and the use ofmechanical and pharmacologic methods were studied. Clinical SU5