average number of SLones was 2. 1(1-9). The average SLone burden (aggregate cross sectional area) was 2.8 cm2 (0.7-6.5). TIle 20 Fr sheath was advanced over an in­

flaLed 6 mm X 10 em balloon. Additional procedures performed during the endoscopic stone retrieva l include e ndopyelotomy in 3 paLients and calycea l diverticulum fulguration in 2. At completion of the procedure, a 16 Fr nephrostomy catheter was placed and usually removed the following day.

The patients were followed for a mean of 14.2 months (3-24 momhs). Non-contrast cr scans were obtained im­mediately following the procedures and abdominal radi­ographs were obtained at 6 month intervals thereafter.

RESULTS,

~ingle prO<edure stone free rate 94Y, (17118)

Mean operative time S4 mi ns

Mean percutan~ous tube duration 22 hI'S

Mean hospit.al !lay 29 hI'S

Major complications 0% (0/ 18)

Minor {omplicalions !Yo (1118)

Mean decrease in hematocrit 3.4'/a

Blood transfu~ioru W, (0118)

RKIlrrent calwli WI (1118)

RKIlrrent UPJ obstruction oy, (Olll

CONCLUSIONS· The Mini-PNL exploits technologic ad­vances that make it possible to remove stones through a

20 Fr sheath. Reducing the sheath size from 30 Fr to 20 Fr decreases the volume of renal parenchyma disrupted by 56%. The high efficacy of PNL is maintained while bleeding and other complications appear to be mini­

mized. The smaller nephrostomy tube can be removed expeclitiously with resultant decreases in hospita l stay.

Slngle procedure stone free rate 94% (17/ 18) Mean oper­ative lime 54 mins Mean percutaneous tube duration 22 hrs Mean hospital stay 29 hrs Major complications 0%

(0/ 18) Minor complications 6% (1/18) Mean decrease in hematocrit 3.4% Blood transfusions 0% (0/ 18) Recurrent

calculi 6% (1 / 18) Recurrent UP] obstruction (JOA> (0/3)

5,02 pm Abstract No. 144

Fluoroscopically Guided Retrograde Ureteral Catheterization j.A. Clark, Toronto, Canada • G j. Robinson • RA . Pugash

PURPOSE: To describe our experience with tluoroscop­ically guided retrograde ureteral ca theterization as an aid to percutaneous nephrolithotomy.

METI-JODS: We attempted retrograde ureteral catheteri­za tion in 8 patients (6 women , 2 men, aged 29-63 years). In all cases, percutaneous nephrolithotomy of a calyceal calculus reqUired prio r percutaneous ne phros­tomy. In two cases, antegrade passage of a guide wire from the nephrostomy tract beyond the calculus had failed; in the remaining cases, this was expected to be

difficult. After exchange of a Foley ca thete r for a 10 French sheath , retrograde ureteral catheterization was attempted with a Cola pinto or Sos Omni catheter and a hydrophil ic guide wire under cystographic guidance.

RESULTS· We succeeded in retrograde ureteral caLheteriza­tion in all 8 patients, allowing placement of a retrograde ureteral occlusion balloon catheter. Injection of the occlu­sion balloon catheter provided sufficient retrograde pelvi­calyceal distension for successful antegrade passage of a gUide wire from Lhe nephrostomy tract beyond the ca­lyceal calculus. All patients subsequent underwent suc­cessful percutaneous nephrolithotomy the operating room.

CONCLUSION Fluoroscopically guided retrograde ureteral catheterization is possible with a high success rate in our

small series of patients. I h.i s technique expands the scope of percutaneous uroradiological intervention.

Scientific Session 19 Hemodialysis: Native Fistula Interventions, Peritoneal Dialysis Moderators: Scott Savader, MD

Lue Turmel-Rodrigues, MD

Wednesday, March 29, 2000 12:30 pm-2:00 pm

12030 pm Abstract No. 145

Outcomes of Percutaneous Intervention in Native Arteriovenous Dialysis Fistulae T W. Clark, Halifax, Canada . R. Abraham .

BX Flemming · j. Heelan . WF. Mason

PURPOSE: The Dialys is Outcomes Quality Initiative (DOQI) guidelines recommend placement of native ar­teriovenous fistulae over synthetic grafts due to superior patency rates . However, limited data exist to define the role of percutaneous in terventions in failing fistulae. We repon primary and secondary patency rates in 52 pa­tients refen·ed for percutaneous intervent ion for poorly functioning fistu lae.

METHODS: Fifty-three na tive arteriovenous fistulae in 52 palients underwent 72 pe rcutaneous interven tions over a 21-mondl period. Fistu lae were occluded or had elevated recirculation, reduced total access blood flow, elevated venous pressures o r difficulty in cannulation with hemodynamically Signi fica nt (>50%) les ion(s) on fistulography. Most patien ts had radial-cephalic fistulae (n; 28, 53%); the rest had brachial-cephalic (n;l1 , 210/0) o r brachial-basilic (n=14, 26%) fistulae. Primary and sec­ondary patency rates follOWing intervention were deter­mined with the Kaplan-Me ier method.

RESULTS: Percutaneous angioplasLY was performed of the native artery (n=2), arteriovenous anastomosis (n=12), proximal fistula (beyond anastomosis, n=27), distal fistula (n=3) o r central venous stenoses (n=8); stenoses were multiple in 11 patients undergoing angioplasty and all 227

PURPOSE: To describe our experience with fluoroscop­ically guided retrograde ureteral catheterization as anaid to percutaneous nephrolithotomy.

Fluoroscopically Guided Retrograde UreteralCatheterizationfA. Clm'k, Toronto, Canada • G j. Robinson •R.A. Pugash

Single procedure stone free rate 94% (17/18) Mean oper­ative time 54 mins Mean percutaneous tube duration 22hrs Mean hospital stay 29 hrs Major complications 0%(0/18) Minor complications 6% (1/18) Mean decrease inhematocrit 3.4% Blood transfusions 0% (0/18) Recurrent

calculi 6% (1/18) Recurrent UP] obstruCtion 0% (0/3)

Abstract No. 14512:30 pm

Wednesday, March 29, 200012:30 pm-2:00 pm

RESULTS:· We succeeded in retrograde ureteral catheteriza­tion in aU 8 patients, allOWing placement of a retrogradeureteral occlusion balloon catheter. Injection of the occlu­sion balloon catheter provided sufficient retrograde pelvi­calyceal distension for successful antegrade passage of agUide wire from the nephrostomy tract beyond the ca­lyceal calculus. AI! patients subsequent underwent suc­cessful percutaneous nephrolithotomy the operating room.

CONCLUSION Fluoroscopically guided retrograde ureteralcatheterization is possible with a high success rate in oursmall series of patients. This technique expands the scopeof percutaneous uroradiological intervention.

difficult. After exchange of a Foley catheter for a 10French sheath, retrograde ureteral catheterization wasattempted with a Colapinto or 50S Omni catheter and ahydrophilic guide wire under cystographic gUidance.

Scientific Session 19Hemodialysis: Native Fistula Interventions,Peritoneal DialysisModerators: Scott Savader, MD

Luc Turme/-Rodrigues, MD

Outcomes of Percutaneous Intervention in NativeArteriovenous Dialysis FistulaeT. W Clark, Halifax, Canada • R. Abraham •

BK Flemming • j. Heelan • WF Mason

PURPOSE: The Dialysis Outcomes Quality Initiative(DOQO guidelines recommend placement of native ar­teriovenous fistulae over synthetic grafts due to superiorpatency rates. However, limited data exist to define therole of percutaneous interventions in failing fistulae. Wereport primary and secondary patency rates in 52 pa­tients referred for percutaneous intervention for poorlyfunctioning fistulae.

METHODS: Fifty-three native arteriovenous fistulae in52 patients underwent 72 percutaneous interventionsover a 21-momh period. Fistulae were occluded or hadelevated recirculation, reduced total access blood flow,elevated venous pressures or difficulty in cannulationwith hemodynamically significant (>50%) lesion(s) onfistulography. Most patients had radial-cephalic fistulae(n=28, 53%); the rest had brachial-cephalic (n=l1 , 21%)or brachial-basilic (n=14, 26%) fistulae. Primary and sec­ondary patency rates follOWing intervention were deter­mined with the Kaplan-Meier method.

RESULTS: Percutaneous angioplasty was performed of thenative artery (n=2), arteriovenous anastomosis (n=12),proximal fistula (beyond anastomosis, n=27), distal fistula(n=3) or central venous stenoses (n=8); stenoses weremultiple in 11 patients undergoing angioplasty and all 227

21 hrs

29 hrs

OY. (0118)

W. (1118)

3.4%

0';' (Oll8)

W. (IIIB)

W, 0/3

94Y. (17118)

54 mins

Abstract No. 144

Blood transfusions

ReaJrTent calculi

Recurrent UP obstruction

RESULTS:

Single procedure stone free rate

Mean operative time

Mean percutaneous tube duration

Mean hospital stay

Maior complications

Minor complications

Mean decrease in hematoait

5:02pm

METHODS: We attempted retrograde ureteral catheteri­zation in 8 patients (6 women, 2 men, aged 29-63years). In all cases, percutaneous nephrolithotomy of acalyceal calculus reqUired prior percutaneous nephros­tomy. In two cases, antegrade passage of a gUide wirefrom the nephrostomy tract beyond the calculus hadfailed; in the remaining cases, this was expected to be

CONCLUSIONS: The Mini-PNL exploits technologic ad­vances that make it possible to remove stones through a20 Fr sheath. Reducing the sheath size from 30 Fr to 20Fr decreases the volume of renal parenchyma disruptedby 56%. The high efficacy of PNL is maintained whilebleeding and other complications appear to be mini­mized. The smaller nephrostomy tube can be removedexpeditiously with resultant decreases in hospital stay.

average number of Slones was 2.1(1-9). The averageSlone burden (aggregate cross sectional area) was 2.8cm2 (0.7-6.5). The 20 Fr sheath was advanced over an in­flaled 6 mm X 10 cm balloon. Additional proceduresperformed during the endoscopic stone retrieval includeendopyelotomy in 3 patients and calyceal diverticulumfulguration in 2. At completion of the procedure, a 16 Frnephrostomy catheter was placed and usually removedthe following day.

The patients were followed for a mean of 14.2 months(3-24 months). Non-contrast CT scans were obtained im­mediately following the procedures and abdominal radi­ographs were obtained at 6 month intervals thereafter.

228

patients with occlusions (n=ll).Stents were placed in 7 central venous stenoses. Immediate technical success was achieved in 66 of 72 interventions (91.7%). Angio­plasty failed in 3 attempts and thrombolysis failed in 3 at­tempts. Thrombolysis was successful in 8 occluded fistu­lae using urokinase (n=2), t-PA (n=4) or mechanical thrombectomy Primary patency (including techni­cal fai lures) at 3, 6, and 12 months was 71.4±6.9%, 48.6±8.6910 and 24.3±12.9%. Secondary patency at 3 months was and 74.3±7.00/o at 6 months.

CONCLUSION: Failing arteriovenous fistulae are amenable to percutaneous intervention, with mid-term patency rates (including technical failures) comparable to those reported for synthetic dialysis grafts. The high rate of technical failures (8.3%) may be due to highly variable angiographic anatomy of native fistulae .

12:41 pm Abstract No. 146

Pen.'Utaneous Management Strategies in Falling Native Arterio-Venous Hemodialysis Fistulae YA1. Dang, Iowa City, IA • Mj. Sharafuddin • CM. Leusner. E.S Dixon • S Sun • KA. Yousef

PURPOSE: Native arterio-venous fistulae (AVFs) have different patterns of failure compared to synthetic AV access. We reviewed our experience with the ap­proaches/treatment strategies in failing AVFs.

MATERIALS AND METHODS: Between January 1998 and August 1999, 46 patients (29 men, 17 women) under­went a total of 59 percutaneous interventions for failing AVF at our institution. Following initial diagnostic fistulo­gram, additional access for intervention was obtained: Antegrade access in 57, combined antegrade and retro­grade access in 10, and retrograde access alone in 2. PTA of the following segments was performed: inflow artery (1), A-V anastomosis (10), post-inflow or segment-I (37), outflow or segment-II/III (30), and central veins (10). Tandem lesions were present in 14 cases. Occlusions oc­curred in 8 and were successfully recanalized in 6. Stents were used in 3 patients segments (2 central veins, 1 seg­ment-II). Adjunctive lytic therapy, mechanical thrombec­tomy, Fogarty sweep of anastomotic plug were required in 8 procedures. There were 3 complications, all man-

successfully percutaneously.

RESULTS: Successful technical outcome « 30% residual stenosis, brisk antegrade t10w, and minimal collaterals) was achieved in 52 procedures (88%). Moderate resid­ual stenosis with suboptimal flow persisted in 2 proce­dures. In 5 procedures revascularization could not be completed because of extensive disease or inability to cross an occlusion. Mean access flow (by transonic dilu­tion flow monitor) increased from 412 ± 250 mllmin to 1396 ± 839 ml/min (p<.002). Mean fo llowup was 6.8 ± 4.3 months (range: 1-16 months). Intention-to-treat pri­

ma ry/primary-assis ted patency rates at I -month, 3-month and 6-months were: 89/89%, 85/89%, and 83/87%, respectively.

CONCLU."ION Percutaneous intervention approaches and strategies in fail ing native AVFs are distinctly differ­ent from those in synthetic AV High technical and clinical success and patency rates can be achieved.

12:52 pm Abstract No. 147

Venous Branch Embolization for Arteriovenous Fistula Salvage J.D. Regan, Winston-Salem, NC • SL Fernandez

PURPOSE: To assess the impact of venous branch em­bolization on radial-cephalic fistula maturation.

MATERIALS AND METllODS: Six consecutive patients with poorly maturing recent (2-8 weeks) radial-cephalic fistulas and one patient with a fistula functioning poorly since its creation 23 months earlier were selected for treatment. Six patients required dialysis with a central venous catheter at the time of treatment. Fistulagrams in all seven patients showed prominent branch veins within 5-6 cm of the arteriovenous CAY) anastomosis di­verting flow from the main superficial draining vein, which was flaccid with no palpable flow. Near the AV anastomosis, all patients had a thrill with good venous distention and a venous stenosis ~ 50%. All seven pa­tients had balloon angioplasty. Branch veins were then ocduded with colis delivered through a 4-Fr catheter. Four patients had pre procedure, postangioplasty, and postembolization duplex examinations. Pre- and post­procedure dialysis records were evaluated.

RESULTS: Preliminary duplex assessment showed a mean velocity of 81 cm/sec in the superficial vein and similar velocities in larger branch veins. After balloon angioplasty, all patients had < 20% residual stenosis but no palpable improvement in flow in the main draining vein. Flow velocities central to the branch veins were unchanged. After embolization, flow was

channeled through a long segment of superficial vein from the wrist to the proximal forearm/antecubetal fossa. A strong thrill was palpable throughout this length in all patients. Mean flow velocity increased to 1.63 m/sec. All seven fistulas developed adequately for use within 4 weeks; six remained functional at 4-18 week follow-up.

CONCLUSION Six of seven failing AV fistulas were sal­vaged by embolizing venous branches and redirecting flow through a long segment of superficial vein, result­ing in short- and intermediate-term improvement in ve­nous flow and fistu la funct ion. Long-term follow-up with a larger patient population is needed to confirm these promising results.

1:03 pm Abstract No. 148

Percutaneous Transiumiual Angioplasty of Brescia-Cimino Arteriovenous Fistula -Analysis of Factors Adversely Affecting Long-Term Patency K. Sugimoto, Kobe, Japan • S Hirota • T Higashino • Y Kuwata • K. Imanaka • K. Sugimura

CONCLUSION: arteriovenous fistulae areamenable to percutaneous intervention, with mid-termpatency rates (including technical failures) comparableto those reported for synthetic dialysis grafts. The highrate of technical failures (8.3%) may be due to highlyvariable angiographic anatomy of native fistulae.

Pen.'Utaneous Management Strategies in FallingNative Arterio-Venous Hemodialysis FistulaeVAl. Dang, Iowa City, IA • Mj. Sharajuddin •CM. Leusner. E.S Dixon • S Sun • KA. Yousej

PURPOSE: Native arterio-venous fistulae (AVFs) havedifferent patterns of failure compared to synthetic AVaccess. We reviewed our experience with the ap­proaches/treatment strategies in failing AVFs.

patients with occlusions (n=l1).Stents were placed in 7central venous stenoses. Immediate technical successwas achieved in 66 of 72 interventions Angio­plasty failed in 3 attempts and thrombolysis failed in 3 at­tempts. Thrombolysis was successful in 8 occluded fistu­lae using urokinase (n=2), t-PA (n=4) or mechanicalthrombectomy Primary patency (including techni­cal failures) at 3, 6, and 12 months was 71.4±6.9%,48.6±8.6% and 24.3±12.9%. Secondary patency at 3months was and 74.3±7.001o at 6 months.

MATERIALS AND METHODS: Between January 1998 andAugust 1999, 46 patients (29 men, 17 women) under­went a total of 59 percutaneous interventions for failingAVF at our institution. Following initial diagnostic fistulo­gram, additional access for intervention was obtained:Antegrade access in combined antegrade and retro-grade access in 10, and access alone in 2. PTAof the following segments was performed: inflow artery(1), A-V anastomosis (10), post-inflow or segment-I (37),outflow or segment-II/III (30), and central veins (10).Tandem lesions were present in 14 cases. Occlusions oc­curred in 8 and were successfully recanalized in 6. Stentswere used in 3 patients segments (2 central veins, 1 seg­ment-II). Adjunctive lytic therapy, mechanical thrombec­tomy, Fogarty sweep of anastomotic plug were requiredin 8 procedures. There were 3 complications, all man-

successfully percutaneously.

RESULTS: Successful technical outcome « 30% residualstenosis, brisk antegrade t10w, and minimal collaterals)was achieved in 52 procedures (88%). Moderate resid­ual stenosis with suboptimal flow persisted in 2 proce­dures. In 5 procedures revascularization could not becompleted because of extensive disease or inability tocross an occlusion. Mean access flow (by transonic dilu­tion flow monitor) increased from 412 ± 250 ml/min to1396 839 ml/min (p<.002). Mean followup was 6.8 ±4.3 months (range: 1-16 months). Intention-to-treat pri­

maly/primary-assisted patency rates at I-month, 3­month and 6-months were: 89/89%, 85/89%, and83/87%, respectively.

Abstract No. 148

Abstract No. 147

1:03 pm

12:52 pm

CONCLU."ION: Percutaneous intervention approachesand in failing native AVFs are distinctly differ­ent from those in synthetic AV High technical andclinical success and patency rates can be achieved.

MATERIALS AND METlfODS: Six consecutive patientswith poorly maturing recent (2-8 weeks) radial-cephalicfistulas and one patient with a fistula functioning poorlysince its creation 23 months earlier were selected fortreatment. Six patients required dialysis with a centralvenous catheter at the time of treatment. Fistulagrams inall seven patients showed prominent branch veinswithin 5-6 cm of the arteriovenous (AV) anastomosis di­verting flow from the main superficial draining vein,which was flaccid with no palpable flow. Near the AVanastomosis, all patients had a thrill with good venousdistention and a venous stenosis :2 50%. All seven pa­tients had balloon angioplasty. Branch veins were thenoccluded with coils delivered through a 4-Fr catheter.Four patients had preprocedure, postangioplasty, andpostembolization duplex examinations. Pre- and post­procedure dialysis records were evaluated.

Percutaneous Transluminal Angioplasty ofBrescia-Cimino Arteriovenous Fistula -Analysis ofFactors Adversely Affecting Long-Term PatencyK. Sugimoto, Kobe, Japan • S Hirota • T Higashino •V Kuwata • K. Imanaka • K. Sugimura

RESULTS: Preliminary duplex assessment showed amean velocity of 81 em/sec in the superficial vein andsimilar velocities in larger branch veins. After balloonangioplasty, all had < 20% residual stenosisbut no palpable improvement in flow in the maindraining vein. Flow velocities central to the branchveins were unchanged. After embolization, flow was

channeled through a long segment of superficial veinfrom the wrist to the proximal forearm/antecubetalfossa. A strong thrill was palpable throughout thislength in all patients. Mean flow velocity increased to1.63 m/sec. All seven fistulas developed adequatelyfor use within 4 six remained functional at4-18 week follow-up.

CONCLUSION: Six of seven failing AV fistulas were sal­vaged by embolizing venous branches and redirectingflow through a long segment of superficial vein, result­ing in short- and intermediate-term improvement in ve­nous flow and fistula function. Long-term follow-upwith a larger patient population is needed to confirmthese promising results.

Venous Branch Embolization for ArteriovenousFistula SalvageJ.D. Regan, Winston-Salem, NC • SL Fern.andez

PURPOSE: To assess the impact of venous branch em­bolization on radial-cephalic fistula maturation.

Abstract No. 14612:41 pm

228

PURPOSE: To clarify the factors adversely affecting tong-term patency afler percutaneous transluminal an­gioplasty (PTA) for hemodialysis Brescia-Cimino arteri­ovenous fistu las.

MATERIAlS AND ME mODS· Between Nnvember 1995 and September 1999, 68 PTA procedures were per­formed on 38 patients with 41 Brescia-Cimino fistulas. Considering that PTA should be a non-invasive mainte­nance therapy for patients with malfunctioning he­modialysis fistu las, we analyzed the secondary patency rates with repeated treatment in addition to the results of primary PTAs.Initial technical success rate for all PTAs and one-year patency rates were calcula ted. Subse­quently, primary and secondary one-year patency rates were compared by using the Kaplan-Meier method be­tween two patient groups. They were classified on the basis of several factors, including age (elder, over 70 yea rs and younger group), with or without diabetes mel­litus (DM), solilary or multiple lesions, long or short seg­ment lesion (1SL or SSL), stenosis or occluSion, and with or without arterial and/or anastomotic lesions (AL).

RESUL7S: Sixty-one of the 68 procedures (90%) were im­mediately successful and 39 of the 41 shunts (95%) were maintained by primary PTA. Primary and secondary one­year patency rates were 300/0 and 47% respectively. As for

the primary patency, the comparative study showed that the ratios were 27% for the elder and 33% for the younger group, 38% for the patients with DM and 23% for the others, 48% for a solilary lesion and 17% for mul­tiple leSions, 43% for occlusions and 18% for stenoses, 32% for LSL and 25% for SSL, and 26% for AI. and 33% for others. As for the secondary patency, it showed that the ratios were 36% for the elder and 57% for the younger group, 41% for the patients with DM and 36% for the oth­ers, 51% for a solitary lesion and 45% for multiple leSions, 49% for LSS and 500/0 for SS1., 56% for occlusions and 39% for stenoses, and 45% for AL and 48% for others. No sta­tistica l Significance was found for any of these factors.

CONCLUSIONS: The long-term patency rate did nol de­teriorate in relation to any factor in our se ries. We con­clude that the indication for PTA shou ld be widened.

1<14 pm Abstract No. 149

Patterns of Failure in Native Artcrio-Venous Hemodialysis Fistulae YM. Dang, Iowa City, L4 • M j. Shara/uddin • CM. Leusner • B.A. Dixon. S. Sun . f( Youse!

PURPOSE: Recent DOQI recommendations call for in­creased number of native al1erio-venous fistulae (AVFs), preViously an uncommon type of hemodialysis access in rhe USA. We reviewed ou r cumulative experience to study the pattern of failure of AVFs.

MATERIALS AND MEIHODS· Between February 1998 and August 1999, 49 patients underwent diagnostiC fistulo" grams for the evaluation of a failing AVF at our instinl­rion. There were 30 men and 19 women, mean age 52.

Forty-four % were diabetic. AVF type was radial-cephalic in 39%, and brachial-cephalic in 61%. Eighty-four % of fistulae had been used successfully for dia lysis. Causes for referral induded abnormal hemodynamiC parameters on routine access sUiveillance (dimin.ished transonic ac­

cess flow rate, high reCirculation, elevated venous pres­sures, or abnormal duplex sonography) in 52%, insuffi­cient hemodialysis, failure of AVF to mature, hand ischemia, arm swelling, and inability to access the fisUlIa.

RESULTS: Distinct angiogra phic patterns were recognized in a failing AVF. Competing outflow (multiple outflow veins w ithout a dominant outflow channeD occurred in

1 ZOAl. Undeveloped! Atretic outflow was encountered in 4%. Bulbar dilatation immediately adjacent to the AV-anas­tomosis occurred in 59%. Pseudoaneurysmlaneurysmal degeneration of the fistula occurred in 180/0. Occlusive dis­ease was far more common than thrombotic disease, with

several recognizable patterns of involvement. Inflow (feeding artery): ZOAl, A-V anastomotic: 17%, Segment-l (post-anastomoticJpost-bulbar) 51%, segment-II (forearm outflow vein} 16%, segment-Ill (ann outflow vein): 26%, and segment-IV (central ve ins) 15%. Muhi-segment stenoses OCCUlTed in 2()}i1. Segmenlal occlusion OCCUlTed in 12%. 'Thrombus usually occurred in association with large aneurysm. In non-aneurysmal AVFs, thrombosis was typicaUy limited to an arterial anastomotic plug) usuaJ ly

with an underlying critical stenosis of segmenl-I.

CONCLUSION Disease patterns in native AVF are dis­tinct from synthetic AY grafts. 111is has important impli­cations on planning and performance of perCUlaneous interventions.

Abstract No. 150

A New Screening and Management Protocol to Increase the Number of Functioning Renal Dialysis Arteriovenous Fistulae A. Falk, New York, NY. V Teodorescll • j. Uribam • H. Milly. j. Lautin • F Moore

PURPOSE: To increase the ratio of renal dialysis arteri­ovenous fistulae (AYF) versus arteriovenous grafts (AYG) through a preoperative screen ing and post oper­ative surveillance and treatment pro[Qcol.

MATERIALS AND ME7710DS .. 123 patients with e nd stage renal disease undenvent upper extremity color doppler ultrasound to eva luate the suitability of their veins to support an AYF. 63 AYF and 15 AYG were placed. 55 patients are currently awaiting access place­ment. AVF that failed to mature (21/63) after 3 months were evaluated by follow up color doppler ultrasound and referred for appropriate intervention.

RESULTS .. Of tl,e 21 AVF that failed to mature 16 had focal proximal stenoses (2 with additional cephalic vein ste noses and 1 with an upper arm cephalic venous oc­clusion), 1 had an upper arm cephalic venous stenosis, 1 had a central venous stenosis, 1 was thrombosed, and 1 was patent. All stenoses were treated with PTA. The occluded AVF was treated with thrombolYSis and PTA. 229

CONCLUSIONS: The long-term patency rate did not de­teriorate in relation to any factor in our series. We con­clude that the indication for PTA should be Widened.

PURPOSE: To clarify the factors adversely affectinglong-term patency after percutaneous transluminal an­gioplasty (PTA) for hemodialysis Brescia-Cimino arteri­ovenous fistulas.

Patterns of Failure in Native Arterio-VenousHemodialysis FistulaeYM. Dang, Iowa City, L4 • MJ. Sharajuddin •CJI1. Leusner • B.A. Dixon· S. Sun. K. Yousej

Abstract No. 1501:25 pm

A New Screening and Management Protocol toIncrease the Number of Functioning RenalDialysis Arteriovenous FistulaeA. Falk, New York, NY. V Teodorescu .}. Uriburri •

J-J. Milty • j. £aulin • F Moore

Forry-four % were diabetic. AVF type was radial-cephalicin 390AJ, and brachial-cephalic in 61%. Eighty-four % offistulae had been used successfully for dialysis. Causesfor referral included abnormal hemodynamic parameterson routine access sUlveillance (diminished transonic ac­cess flow rate, high recirculation, elevated venous pres­sures, or abnormal duplex sonography) in 52%, insuffi­cient hemodialysis, failure of AVF to mature, handischemia, arm swelling, and inability to access the fistula.

RESULTS: Distinct angiographic patterns were recognizedin a failing AVF. Competing outflow (multiple outflowveins without a dominant outflow channel) occurred in12%. Undeveloped!Atretic outflow was encountered in4%. Bulbar dilatation immediately adjacent to the AV-anas­tomosis occurred in 59%. Pseudoaneurysm/aneurysmaldegeneration of the fistula OCCUlTed in 18%. Occlusive dis­ease was far more common than tluumbotic disease, withseveral recognizable patterns of involvement. Inflow(feeding artery); 2%, A-V anastomotic: 17%, Segment-I(post-anastomotic/post-bulbar); 51%, segment-II (forearmoutflow vein): 16%, segment-Ill (arm outflow vein): 26%,and segment-IV (central veins): 15%. Multi-segmentstenoses OCCUlTed in 20%. Segmental occlusion OCCUlTedin 12%. lhrombus usuaUy OCCUlTed in association withlarge aneurysm. In non-aneurysmal AVFs, thrombosis wastypicaUy limited to an arterial anastomotic plug, usuallywith an underlying critical stenosis of segment-I.

CONCLUSION: Disease patterns in native AVF are dis­tinct from synthetic AV grafts. This has important impli­cations on planning and performance of percutaneousintelventions.

PURPOSE: To increase the ratio of renal dialysis arteri­ovenous fistulae (AVF) versus arteriovenous grafts(AVG) through a preoperative screening and post oper­ative sUlveillance and treatment protocol.

MATERIALS AND ME7HODS: 123 patients with endstage renal disease undelwent upper extremity colordoppler ultrasound to evaluate the suitability of theirveins to support an AVF. 63 AVF and 15 AVG wereplaced. 55 patients are currently awaiting access place­ment. AVF that failed to mature (21/63) after 3 monthswere evaluated by follow up color doppler ultrasoundand referred for appropriate intervention.

RESULTS: Of tile 21 AVF that failed to mature 16 hadfocal proXimal stenoses (2 with additional cephalic veinstenoses and 1 with an upper arm cephalic venous oc­clusion), 1 had an upper arm cephalic venous stenosis,1 had a central venous stenosis, 1 was thrombosed, and1 was patent. All stenoses were treated with PTA. Theoccluded AVF was treated with thrombolysis and PTA. 229

Abstract No. 1491:14 pm

RESULTS: Sixty-one of the 68 procedures (90%) were im­mediately successful and 39 of the 41 shunts (95%) weremaintained by primary PTA. Primary and secondary one­year patency rates were 30% and 47% respectively. As for

the primary patency, the comparative study showed thatthe ratios were 27% for the elder and 33% for theyounger group, 38% for the patients with DM and 23%for the others, 48% for a solitary lesion and 170/0 for mul­tiple lesions, 43% for occlusions and 18% for stenoses,32% for LSL and 25% for SSL, and 26% for Ai and 33% forothers. As for the secondary patency, it showed that theratios were 36% for the elder and 57% for the youngergroup, 41% for the patients with DM and 36% for the oth­ers, 51% for a solitary lesion and 45% for multiple lesions,49% for LSS and 50% for SSL, 56% for occlusions and 39010for stenoses, and 45% for AL and 48% for others. No sta­tistical significance was found for any of these factors.

MATERiAIS AND jIIJElliOD5- Between November 1995and September 1999, 68 PTA procedures were per­formed on 38 patients with 41 Brescia-Cimino fistulas.Considering that PTA should be a non-invasive mainte­nance therapy for patients with malfunctioning he­modialysis fistulas, we analyzed the secondary patencyrates with repeated treatment in addition to the results ofprimary PTAs.Initial technical success rate for all PTAsand one-year patency rates were calculated. Subse­quently, primary and secondary one-year patency rateswere compared by using the Kaplan-Meier method be­tween two patient groups. They were classified on thebasis of several factors, including age (elder, over 70years and younger group), with or without diabetes mel­litus (DM), solitary or multiple lesions, long or short seg­ment lesion (LSL or SSL), stenosis or occlusion, and withor withollt arterial and!or anastomotic lesions (AL).

PURPOSE: Recent DOQI recommendations call for in­creased number of native arterio-venous fistulae CAVFs),previously an uncommon type of hemodialysis accessin the USA. We reviewed our cumulative experience tostudy the pattern of failure of AVFs.

MATERiALS AND MElHODS: Between February 1998 andAugust 1999, 49 patients undelwent diagnostic fistulo­grams for the evaluation of a failing AVF at our institu­tion. There were 30 men and 19 women, mean age 52.

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In 19 patients 21 lesions were treated wilh percutaneous intervention. All 21 percutaneous interventions were tec.lmically successful. Currently, 12/ 19 treated AVF are being used for hemodialysis access. 4/ 19 are awaiting maturation, 3/19 have occluded, and 2/ 19 are patent, but have not manned. One complication occurred, dis­section of a cephalic vein, which was treated with addi­tional PTA. FoUow up was 2- 18 months, with a mean of 8 months. 3 patients died during the follow up period, 1 with a working AVF and 2 died before access placement. Of the in itial 63 AVF placed, 5/ 63 were converted to AVG and 6/63 were converted to tunne lled catheters.

CONCLUSIONS: The number of more desirable AVF ver­sus AVG can be increased by preoperative screening. AVF that fail to mature can be successfully treated with percutaneous intelvention. Venous stenoses in these pa­tients respond ro angiop lasty so that AVF function can be established or restored.

1036 pm Abstract No. 151

Safety and Efficacy of Tenckhoff cathete r Manipulation CA . Bonawitz, Chapel Hill, NC • IS. Sandhu ·

PF Jaques · S.M. Weeks . M.A . Mauro

PURPOSE: To determine the safety and efficacy of per· cutaneous fluoroscopically guided manipulation of mal­functioning peritoneal dialysis catheters.

MATERIALS AND METHODS: A retrospective analysis encompassing 9 years and 59 patients was performed of seventy nine Tenckhoff studies obtained due to ca theter dysfunction (poor/ non-funct ion: n= 57, pain/discom­fort: n= 6 , malpoSition: n= 5, not specified: n= 9). Ma­nipulation was performed using a malleable steerable steel cannula . Contrast injection without manipulat ion was performed 5 times. Technical success, patency rates and complications were recorded.

RESULTS: lnitial technical success resulting in adequate catheter function and position was achieved in 91% (n=67). Manipulation failure was observed in 9010 (n=7). Only contrast injection was performed in 5 instances with revealed appropriate position and function in 3, catheter tip located in the transverse colon in one and extensive kinking of the ca theter with the tip located in a small cavity which did not corrununicate with the peri­toneum in anolher. Ten patients were lost to fo llow up.

Primary patency rates (from time of calheter manipula­tion)had a bimodal distribution and ranged from 2-133Od (mean:=244d, median=135d). Secondary patency rates, also bimodal, ranged from J- 950d (mean~300d, me· dian=86d). Factors predisposing to manipulation and long term patency failures were: sub-optimal surgical placement or excessive ca theter length 15% (n=9) and peritoneal adhesions 19% (n=I1). One patient developed peritonitis with in 1 month of the manipulation.

CONCLUSJON Fluoroscopically guided Tenckhoff mao nipulat ion and COnlrast evaluat ion is safe and e f-

ficac ious in preserving catheter function thereby pro­longing peritoneal dialysis.

Abstract No . 152

Percutaneous RadiolOgic Placement of Continuou s Ambulatory Pe ritoneal Dia lysis Catheters S}. Savadet; Indianapolis, IN · IF. Geschwind • G.B. Lund · P j. Scheel

PURPOSE: To evalua te the efficacy of percutaneous ra­diologic placement of continuous ambulatory peri­toneal dialysis (CAPO) catheters.

MA7ERlALS AND METHODS: Nineteen end-stage renal disease patients (male, n=11; female , n=8) with a mean age of 58 years (range, 38--85 years) underwent percu­taneous placement of a corrunercially available CAPD catheter. All procedures were performed utilizing con­scious sedation and on an oul-patient basis. Patients were followed for technical success, complications, ca theter survival, and long-te rm outcome.

REWJLTS: The technical success rate for catheter place­ment was 95% (18/19). Complications included one (5%) case of procedure related peritonitis and one (5%) fa iled procedure. Mean and median catheter survival was 320 and 289 days, respectively (range. 33-{323 days). A Ka­plan-Meier survival analysis yielded a 6, 12, and 24 month probabi liry of catheter surviva l of .89, .81, and .81, respectively. Long-term outcomes included: continued CAPO with same catheter originally placed, 0;9 (47%); death, n~6 (32%) (all deaths secondary to a)·morbid dis· ease) ; successful renal transplant, n:;:;:2 (10.5%); and re­mained on or converted to hemodialysis, n=2, 00.5%).

CONCLUSION Percutaneous radiologic placement of CAPO catheters has a high technical success rate, a low incidence of procedure related complications, and can be performed on an o m-patient basis. Catheter survival is comparable to tha t seen in surgically placed catheter series.

Scientific Session 20 Stents/Brachytherapy Moderators: Dieter Liermann, MD

Louis G. Martin, MD

Wednesday, March 29, 2000 12:30 pm-2:00 pm

12dOpm Abstrac t No. 153

Comparlsion in the State o f lumina Afte r Expe rime n tal Placement o f Bare and Covered Z-Stent in Various Types of Bloo d Vessels Y Sakai, Osaka, Japan . T Kaminou • M. Isola · X. Tong . K. Nakamura . R. Yamada

PURPOSE: Although several studies on stenosis after placement of stent have been performed , reports of si­multaneous examination of aneries, veins and portal

CONCLUSIONS: The number of more desirable AVF ver­sus AVG can be increased by preoperative screening.AVF that fail to mature can be successfully treated withpercutaneous intervention. Venous stenoses in these pa­tients respond to angioplasty so that AVF function canbe established or restored.

In 19 patients 21 lesions were treated with percutaneousintervention. All 21 percutaneous interventions wereteclmically successful. Currently, 12/19 treated AVF arebeing used for hemodialysis access. 4/19 are awaitingmaturation, 3/19 have occluded, and 2/19 are patent,but have not matured. One complication occurred, dis­section of a cephalic vein, which was treated with addi­tional PTA. Follow up was 2-18 months, with a mean of8 months. 3 patients died during the follow up period, ]with a working AVF and 2 died before access placement.Of the initial 63 AVF placed, 5/63 were converted toAVG and 6/63 were converted to tunnelled catheters.

ficacious in preserving catheter function thereby pro­longing peritoneal dialysis.

Percutaneous Radiologic Placement of ContinuousAmbulatory Peritoneal Dialysis CathetersSj. Savader, Indianapolis, IN.].F Geschwind •

G.B. Lund • Pj. Scheel

Abstract No. 1521:47 pm

PURPOSE: To evaluate the efficacy of percutaneous ra­diologic placement of continuous ambulatory peri­toneal dialysis (CAPD) catheters.

MATERiALS AND MEmODS: Nineteen end-stage renaldisease patients (male, n=11; female, n=8) with a meanage of 58 years (range, 38-85 years) underwent percu­taneous placement of a commercially available CAPDcatheter. All procedures were performed utilizing con­scious sedation and on an out-patient basis. Patientswere followed for technical success, complications,catheter survival, and long-term outcome.Abstract No. 1511:36 pm

PURPOSE: Although several studies on stenosis afterplacement of stent have been performed, reports of si­multaneous examination of arteries, veins and portal

Scientific Session 20Stents/BrachytherapyModerators: DieterLiermann, MD

Louis G. Martin, MD

Comparision in the State of Lumina AfterExperimental Placement of Bare and CoveredZ-Stent in Various Types of Blood VesselsY. Sakai, Osaka, japan • T. Kaminou • M. Isota •

X. Tong • K. Nakamura • R. Yamada

RE'lULTS: The technical success rate for catheter place­ment was 95% (18/19). Complications included one (5%)case of procedure related peritonitis and one (5%) failedprocedure. Mean and median catheter survival was 320and 289 days, respectively (range, 33-823 days). A Ka­plan-Meier survival analysis yielded a 6, ]2, and 24month probability of catheter survival of .89, .8], and .81,respectively. Long-term outcomes included: continuedCAPD with same catheter originally placed, n=9 (47%);death, n=6 (32%) (all deaths secondary to co-morbid dis­ease) ; successful renal transplant, n=2 00.5%); and re­mained on or converted to hemodialysis, n=2, (10.5%).

CONCLUSION: Percutaneous radiologic placement ofCAPD catheters has a high technical success rate, alow incidence of procedure related complications, andcan be performed on an out-patient basis. Cathetersurvival is comparable to that seen in surgically placedcatheter series.

Abstract No. 15312:30 pm

Wednesday, March 29, 200012:30 pm-2:00 pm

CONCLUSION: Fluoroscopically guided Tenckhoff ma­nipulation and contrast evaluation is safe and ef-

PURPOSE: To determine the safety and efficacy of per­cutaneous fluoroscopically guided manipulation of mal­functioning peritoneal dialysis catheters.

Safety and Efficacy of Tenckhoff CatheterManipulationCA. Bonawitz, Chapel Hill, NC· ].S. Sandhu •

PFjaques • S.M. Weeks • MA. Mauro

MATERIALS AND METHODS: A retrospective analysisencompassing 9 years and 59 patients was performed ofseventy nine Tenckhoff studies obtained due to catheterdysfunction (poor/non-function: n= 57, pain/discom­fort: n= 6 , malposition: n= 5, not specified: n= 9). Ma­nipulation was performed using a malleable steerablesteel cannula . Contrast injection without manipulationwas performed 5 times. Technical success, patency ratesand complications were recorded.

RESULTS: Initial technical success resulting in adequatecatheter function and position was achieved in 91%(n=67). Manipulation failure was observed in 9% (n=7).Only contrast injection was performed in 5 instanceswith revealed appropriate position and function in 3,catheter tip located in the transverse colon in one andextensive kinking of the catheter with the tip located ina small cavity which did not communicate with the peri­toneum in another. Ten patients were lost to follow up.

Primary patency rates (from time of catheter manipula­tion)had a bimodal distribution and ranged from 2-]330d(mean=244d, median=]35d). Secondary patency rates,also bimodal, ranged from 1-950d (mean=300d, me­dian=86d). Factors predisposing to manipulation andlong term patency failures were: sub-optimal surgicalplacement or excessive catheter length ]5% (n=9) andperitoneal adhesions 19% (n=] 1). One patient developedperitonitis within 1 month of the manipulation.

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