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rCD in a group of patients with proved infected pancre­atic necrosis.

MATERIALS AND METHODS: Thirty patients with in­fected pancreatic necrosis, as determined by contrast­enhanced computed tomography and guided-needle as­piration, underwent PCD. The degree of necrosis rangedfrom 30% to >50% (subtotal). The average computedtomography severity index was 7.8. One to three 12­28-F catheters were placed in each patient and vigor­ously irrigated.

RESULTS: Fourteen (47%) patients were cured and didnot require surgery. Mean drainage time was 80 days(range, 21-153 days). Ten patients (33%) required ne­

crosectomy because of uncontrolled sepsis or inad­equate drainage, and three of these patients died (mor­tality rate, 10%). Six patients required elective pancreaticresection due to pancreatic fistulas, and three of thesepatients had central necrosis. No direct complications ofcatheter drainage occurred.

CONCLUSION Infected pancreatic necrosis was treatedeffectively by PCD alone or with elective pancreatic re­section in 67% of cases.

Take Home Points:1. Infected pancreatic necrosis is not a contraindication

for PCD.

2. PCD for infected necrosis may be effective in as manyas 67% of patients.

3. Central necrosis indicates a stronger likelihood ofPCD failure.

2:45 pm

Appropriateness of scvm Quality-ImprovementThresholds for Percutaneous Abscess and FluidDrainage in Adults in Community PracticeD. Sacks, MD, West Reading, PA • j.M. Painter, MD •Rj. Gregor, MD

PURPOSE: To evaluate the generalizability to a commu­nity hospital practice of the quality-improvement thresh­olds for success and complications for percutaneous ab­scess and fluid drainage (PAFD) in adults.

MATERIALS AND METHODS: Records of 200 PAFD pro­cedures were reviewed retrospectively. Cases wereevaluated for success, partial success, failure, and com­plications using the quality-improvement guidelines cri­teria of the Society of Cardiovascular and InterventionalRadiology (SCVIR).

RESULTS: Forty percent of collections were complex (de­fined in the SCVIR quality-improvement guidelines asmultiple abscesses, abscess due to Crohn disease, pan­creatic collections, drainage route that traverses thebowel or pleura, infected clot, and infected tumor).Drainage was successful (87%), partially successful (5%),or failed (8%). There were 3% complications, of whichonly 15% were major. Although 50% of the drainages

were performed by one physician, there was no asso­ciation of procedure success or complication with thephysician or physician experience.

CONCLUSIONS: The success and complication rates foradult PAFD reported in the literature from academic cen­ters are reproducible in a community practice of physi­cians with varying levels of training and experience.These published rates are appropriate for setting quality­improvement thresholds for community practices. It maynot be appropriate to set thresholds for complications attwice the published rates.

Take Home Points:1. Percutaneous abscess and fluid drainage in a com­

munity hospital setting has success and complicationrates similar to academic settings.

2. Published success rates for percutaneous abscess andfluid drainage are appropriate for setting quality­improvement thresholds.

3. Setting thresholds for complications at twice the pub­lished rates may be too lenient to improve the qualityof practice.

Scientific Session 5Thrombolysis and ThrombectomyModerator: Mark Mewissen, MD, Milwaukee, WI

1:30 pm

Long-Term Follow-up of Aggressive CatheterTechnique for Massive PulmonaryEmbolus ThrombolysisPE Tb01pe, MD, Omaha, NE • x.x. Zhan, MD

PURPOSE: To evaluate the efficacy and long-term resultsof aggressive, catheter-embedded thrombolYSis foracute, severely symptomatic pulmonary embolus (PE).

MATERIALS AND METHODS: Fourteen patients (sevenwomen and seven men) received aggressive catheter­directed lysis for acute PE between January 1989 andJuly 1996. After diagnostic angiography and baselinepulmonary pressures, urokinase was delivered directlyinto the embolus with associated maceration when pos­sible. A bolus of 500,000-1,000,000 IU was given over aperiod of 20-60 minutes for massive obstruction. An in­fusion of 100-300,000 IU/hour was continued, and in­terval angiograms and pressures were obtained. Uroki­nase was infused from 10--40 hours. An intravenous cath­eter filter was placed in eight (57%) of the patients.Severity and improvement of obstruction and flow wereassessed using the Miller index (MI).

RESULTS: Mean duration of infusion was 21 hours; themean dose of urokinase was 3,500,000 IV. Twelve of 14(86%) patients had documented deep venous thrombo­sis. Six patients were in class I shock (systolic bloodpressure <90 mmHg), and the MI was 23 before lysis and11.8 after lysis. Class II patients (systolic blood pressure

>90 mmHg) had a MI of 10.9 before lysis and 5.8 afterlysis (P < .05). Immediate survival was 93% (n = 13), andthe 36-month mean follow-up survival rate is 93% (n =13), the recurrent deep venous thrombosis rate is 7% (n= 1), and recurrent PE rate is 0%.

CONCLUSIONS: Aggressive catheter-directed thromboly­sis for massive obstructive PE that causes hemodynamicinstability can decrease mortality rates. Patients withsymptoms from diffuse PE also respond rapidly to intra­pulmonary lytic therapy. However, although patientswith a diffuse nonobstructive pattern of PE may respondto systemic therapy, massive obstructive emboli requirean aggressive catheter technique to ensure timely clinicalimprovement.

Take Home Points: Aggressive catheter manipulationand intrathrombic lytic therapy improve survival in pa­tients with massive obstructive PE. A pattern of diffusePE may respond to systemic therapy.

1:45 pm

Popliteal Approach to Treat PWegmasiaCerulea Dolens

T.O. McNamara, MD, Los Angeles, CA

PURPOSE: To assess the safety and effectiveness of theuse of the popliteal vein to introduce a thrombolysisinfusion system to treat phlegmasia cerulea dolens.

MATERIALS AND METHODS: Six consecutive patientswith clinical findings of phlegmasia cerulea dolens andultrasound evidence of thrombosis of the iliac, femoral,popliteal, and trifurcation veins were treated. Ultrasoundwas used to visualize the popliteal vein. A triaxial infu­sion system was introduced. Thrombolysis was accom­plished with concomitant transcatheter infusions of uro­kinase and heparin. Underlying stenoses were treatedwith stents.

RESULTS: Antegrade flow was restored with associatedclearing of pain and reduction of leg swelling within 24hours. No clinical evidence of pulmonary embolism wasnoted. All patients experienced complete clearing ofswelling within 48 hours. One patient with a paraneo­plastiC hypercoagulable state had recurrence and under­went amputation. There were no deaths and only onepopliteal hematoma.

CONCLUSION Transpopliteal thrombolysis provides aprompt, Simple, and effective method to treat limb­threatening phlegmasia cerulea dolens.

Take Home Points:1. The popliteal approach is simple.

2. It provides for easier traversal of the valves and en­ables thrombolysis to immediately span the occlusionfrom the popliteal through the iliac levels.

2:00 pm

Catheter-Directed Fibrinolysis and Interventionfor Iliofemoral Deep Venous Thrombosis:Technique and Results

IF. Benenati, MD, FACC, FACR, Miami, FL • G]

Becker, MD • G. Zemel, MD • B. T. Katzen, MD • L.B.GoodWin, RN • S. Samuels, MD

PURPOSE: Catheter-directed fibrinolytic infusion is atherapeutic option to treat iliofemoral deep venousthrombosis (DVT). This therapy was studied in 15 pa­tients.

MATERIALS AND METHODS: Fifteen patients with ilio­femoral DVT documented by duplex or venographywere treated using catheter-directed fibrinolytic infusion.Symptoms lasted from 5 hours to 5 months. Access wasobtained from either the internal jugular vein (n = 7) orfrom the ipsilateral popliteal vein (n = 8). Coaxial infu­sions of urokinase were performed with the dose rang­ing from 60,000 to 250,000 IV/hour (average, 83,000 IV/hour). The duration of urokinase therapy ranged from 20to 120 hours (mean, 23.5 hours). During thrombolyticinfusion, patients were given heparin (partial thrombo­plastin time ranging from 1.5 to 2x normal). Lysis wascontinued until symptoms resolved or was terminated ifno change occurred clinically or by imaging in 72 hours.An additional intervention was performed in 10 of 14patients C7 stents, 3 venous angioplasties). In the remain­ing patients, no underlying lesions could be identified.All patients were given heparin and warfarin sodium for6 months, except for one patient who required an infe­rior vena cava catheter filter because of intraperitonealbleeding, which was the only major complication. Minorcomplications included three hematomas, one cases ofcellulitis, and one intermittent fever. Immediate resultsshowed restoration of patency in the iliac vein in 13 of 15patients. Three of the 13 patients with patent iliac veinshad residual distal thrombi. Two patients had no changewhen compared with results of their initial examinations.Follow-up ranges from 3 weeks to 18 months. One of 13patients experienced rethrombosis. The remaining veinsare patent and unchanged or improved from their post­procedure examination.

CONCLUSIONS: Catheter-directed thrombolytic infusionis safe and effective for treating patients with symptomssecondary to iliofemoral DVT. After thrombolysis, under­lying lesions frequently are found and should be treatedto prevent rethrombosis. Results suggest this therapymay be effective in preventing long-term sequelae.

Take Home Points:1. Catheter-directed thrombolytic infusion for an ilio­

femoral DVT is safe and effective.

2. Various techniques may be used, including internaljugular and direct popliteal vein access.

3. Underlying lesions are often responsible for the DVT.185

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2:15 pm

Transcatheter Regional Urokinase Therapy toManage Inferior Vena Cava Thrombosis].F. Angle, MD, Charlottesvitte, VA .].K. McGraw, MD

• A.H. Matsumoto, MD

PURPOSE: To study the efficacy of local infusions of uro­kinase to treat symptomatic inferior vena cava (lVC)thrombosis.

MElliODS: Seven patients with IVC thrombosis under­

went local catheter-directed infusion of a thrombolyticagent. Catheter-directed thrombolysis was performed us­

ing as many as three access sites. Urokinase was infused

for an average of 79 hours for a mean total dose of 7.1million units. Clinical or radiographic follow-up was ob­tained in all patients.

RESULTS: lnfrarenal IVC thrombus was identified in allpatients. Three had extension of thrombus proximal tothe renal veins. Six of seven (86%) IVCs were success­

fully thrombolysed with minimal residual thrombus.Three of the seven patients (43%) had a preexisting IVC

filter, one had a filter placed at the time of thrombolysis,and two had a Neuhaus infusion catheter placed as a

temporary filter. Adjunctive balloon angioplasty was per­

formed in three patients. No vascular stents were placed.

Four patients had a hypercoagulable state and one pa­tient had an occult metastatic malignancy. No seriouscomplications were encountered, although one patient

died of an unrelated cause 5 days after therapy. Clinicalfollow-up in the remaining six patients ranged from 2 to24 months. All six patients had continued improvedlower extremity swelling after the procedure. None ofthe patients had symptoms of recurrent IVC thrombosis.

CONCLUSIONS: Local infusions of urokinase are a reli­able and safe method to manage acute IVe thrombosis.

Take Home Points:1. Catheter-directed thrombolysis is effective treatment

for acute Ive thrombosis.

2. Regional therapy of IVC thrombus is a safe therapywith good long-term results.

3. Vascular stents are not required for good long-term

results.

2:30 pm

Percutaneous Mechanical Thrombectomy ofInferior Vena Cava Thrombosis with the AmplatzThrombectomy DeviceX. Gu, MD, Minneapolis, MN • Mj. Sharafuddin, MD

• M. Urness .].1. Titus, MD • K. Amplatz, MD

PURPOSE: To evaluate the efficacy of the Amplatzthrombectomy device (ATD) in an experimental modelof subacute inferior vena cava (IVC) thrombosis.

MATERIALS AND MElliODS: ATD is an 8-Fr recircula­

tion-type mechanical thrombectomy device that uses a

recessed helical impeller, coaxially driven up to 150,000

rpm. Thrombectomy was performed in 23 dogs, in

which 6-15-day-old infrarenal IVC thrombosis was in­duced by placing an occlusion balloon. The transjugularapproach was used in five animals, and a two-step trans­

femoral approach was used in 18.

RESULTS: Excellent anatomic patency of IVC was re­stored in all 23 animals. Mean device activation time was

4.35 ± 2.5 minutes. Post-thrombectomy venographyshowed smooth IVC walls in 14 dogs, whereas muralthrombus remained in nine dogs without significant flow

restriction (less than 20% narrowing in seven, 20-30%

narrowing in two). No angiographic or histopathologic

evidence of mechanical IVC wall damage was present,although phlebitic changes were common. No new pul­monary emboli were noted on post-thrombectomy an­

giograms. However, a slight increase in mean pulmonaryartery pressure occurred, with a corresponding decreasein arterial oxygen saturation. Examination of explantedlungs from 11 animals showed 100-500-pm pulmonaryarteriolar microemboli in four (three of three transjugu­

lar, one of eight transfemoraO.

CONCLUSION: ATD is effective in clearing 1-2-week-old

IVC thrombosis.

Take Home Points:1. Mechanical thrombectomy using ATD is highly effec­

tive in treating subacute IVC thrombosis.

2. Pulmonary microembolization is well tolerated andmuch less common using the transfemoral approach.

2:45 pm

Percutaneous Hydrodynamic ThrombectomyUsing the Hydrolyser SystemM. Henry, MD, Essey Les Nancy, France • M. Amor,

MD • I. Henry, MD • ].M. Porte, MD • O. Tricoche,

MD • E. Leborgne, MD

PURPOSE: To present our clinical experience with a newmechanical hydrodynamic thrombectomy system (Hy­drolyser) using the Venturi effect. This device was usedto remove thrombi from native arteries, arterial grafts,the venous system, and pulmonary arteries.

MATERIALS AND MElliODS: The Hydrolyser is a re­cently developed 7-Fr, double-lumen, over-the-wirecatheter. The device has been used in 50 patients (29men, 21 women; mean age, 66,2 ± 13.1 years [range,

40-90 years]) with recent thromboses. Occlusion time

ranged from 1 to 30 days (mean, 8.2 ± 7.3 days); throm­bus length ranged from 4 to 35 em (mean, 17.7 ± 10.2em). Thrombi were located in native arteries (n = 35:femoropopliteal, 28; iliac, 7), arterial grafts (n = 9), su­perior vena cava (n = 2), axillary vein (n = 2), and pul­monary artery (n = 2). Approaches were arterial femoralantegrade (n = 22), retrograde (n = 7), contralateral (n =

14), popliteal arterial (n = 1), venous femoral (n = 5), and

venous humeral (n = 1).

RESULTS: Technical success was achieved in 41 patients(82%) in native arteries (27 of 35, 77%), arterial grafts (8of 9,89%), pulmonary artery (2 of 2), superior vena cava

(2 of 2), and axillary vein (2 of 2). Thrombi were esti­mated angiographically to be removed by the Hydroly­ser 72.5% ± 22%. Adjunctive therapy included angio­plasty (n = 38, 19 immediate stents implantations),thromboaspiration (n = 17), and reduced-time fibrinoly­sis (n = 11). One complication occurred-a distal embo­lism cured by thromboaspiration. In nine patients theprocedure failed and required surgery (bypass orFogarty). At 30 days, 37 vessels remained patent (74%).

CONCLUSIONS: The Hydrolyser system is a promisingconcept for percutaneous thrombectomy. It is quick, re­liable, efficient, can be combined with other techniquessuch as thromboaspiration, and completed by reduced­time fibrinolysis. This technique also may offer an alter­native to thrombolysis and surgical thrombectomy.

Take Home Points: The Hydrolyser system is a prom­ising concept for percutaneous thrombectomy. It isquick, reliable, efficient, can be combined with othertechniques such as thromboaspiration, and completedby reduced-time fibrinolysis. This technique also mayoffer an alternative to thrombolysis and surgical throm­bectomy.

Scientific Session 6Venous Access and Dialysis CathetersModerator: Gwen Nazzarian, MD, Minneapolis, MN

1:30 pm

Ultrasound-guided Cannulation of the InternalJugular Vein: Complications andAnatomic ConsiderationsA.C. Gordon, MBBS, FRCR, Calgary, Alberta, Canada

• ]. Saliken, MD, FRCPC • D. johns • R. Gray, MD,FRCPC

PURPOSE: To examine success and complication ratesfor ultrasound-guided cannulation of the internal jugularvein (lJV) compared with blind techniques and to ob­serve the effect of variations in the anatomy of the vein.

MAIERIALS AND METHODS: Data were collected pro­spectively for 621 cases of sonographically guided can­nulation of the lJV. In all cases the side of puncture,whether the procedure was successful, and any imme­diate complications were recorded. In 519 cases thenumber of passes required was recorded, and in 524 thenumber of walls punctured was noted. In 431 cases, thelocation of the I]V relative to the carotid artery was re­corded. Finally the diameter of the I]V and its distancefrom the skin were noted in 557 cases.

RESULTS: Cannulation was successful in all of the cases.There were 483 (77.8%) cannulations of the right and 138(22.2%) of the left I]V. Complications occurred in 13cases (2.09%). Only one required therapy. There were450 (85.9) single-wall punctures, and 465 (89.6%) of thepunctures were made with one pass. In 199 cases

(46.2%) the vein was anterolateral to the carotid artery.In 22 cases (5.1%) the vein lay medial to the artery.

CONCLUSIONS: Ultrasound-guided cannulation of theI]V is superior to blind techniques. Sonographic visual­ization reduces the effect of variations in anatomy andoperator experience on the success of cannulation.

Take Home Points: Ultrasound guidance will decreasethe complication rate and thus is advisable for cannula­tion of the I]V when available.

1:45 pm

Effect of Vitacuffs on the Short-term InfectionRate of Tunneled Central CathetersG.K. Nazarian, MD, Minneapolis, MN • C.A. Dietz, jr.,

MD • H. Bjarnason, MD • D. w: Hunter, MD

PURPOSE: To determine whether VitaCuffs (Arrow Inter­national, Reading, FA) reduce the infection rate of tun­neled central venous catheters.

MA TERIALS ANDMETHODS: Sixty-seven patients havingbone marrow transplants received tunneled central ve­nous catheters during a 33-month period. Twenty-ninepatients received Hickman catheters (Bard Access Sys­tems, Salt Lake City, un with VitaCuffs and 38 patientsreceived Hickman catheters without VitaCuffs. Infectionwas defined as bacteremia with no clear source otherthan the catheter. The medical records were reviewedretrospectively up to 30 days after line placement. Thenumber of catheter-related infections were compared forthe two groups using the Cox F-test.

RESULTS: Catheters were in place 790 catheter-days forcatheters with and 1,055 catheter-days for catheters with­out VitaCuffs. Before 30 days, three patients died, sixcatheters were removed due to suspected infection, twoinadvertently, two for access thrombosis, and one be­cause it was no longer needed. Two catheters with andeight catheters without VitaCuffs were removed for cath­eter-related infection (P < .05).

CONCLUSION VitaCuffs significantly reduce the numberof catheter-related infections in patients having bonemarrow transplants.

Take Home Points:1. Catheter-related infection is a serious problem in im­

munocompromised patients.

2. Tunneled catheters come with and without VitaCuffs.

3. Reduced catheter-related infections occurred whencatheters with VitaCuffs were placed.

2:00 pm

Randomized Study of Silver Coating (Silvergard)to Prevent Infection in Tunneled HemodialysisCatheters: Interim ReportS.O. Trerotola, MD, Indianapolis, IN. M.S. johnson,MD • H. Shah, MD • Vj. Harris, MD • M. Kraus, MD

• M. McKusky, RN

PURPOSE: To determine whether silver coating (Silver­gard, SG) applied to tunneled hemodialysis catheters re-

187