Abstract No. 90: Failure to mature hemodialysis access fistulas: a 3-step approach to successful salvage

Abstract No. 90: Failure to mature hemodialysis access fistulas: a 3-step approach to successful salvage

SCIENTIFIC SESSIONS: MONDAY Scientific Session 7 Dialysis Interventions Monday, March 26, 2012 8:00 AM – 10:00 AM Room: 122 8:00 AM Abstract No. 88 ...

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SCIENTIFIC SESSIONS: MONDAY

Scientific Session 7 Dialysis Interventions Monday, March 26, 2012 8:00 AM – 10:00 AM Room: 122 8:00 AM

Abstract No. 88

Femoral dialysis catheter access: results in 311 catheter insertions

Purpose: To determine the safety and functionality of femorally placed dual lumen dialysis catheters in a large patient population. Materials and Methods: From a prospectively collected data base, all patients receiving dialysis catheter access using the common femoral vein were collected from January 2008 through December 2010. Electronic and paper medical records were then retrospectively reviewed for demographic and clinical data related to the catheter placement and follow up. Images were reviewed from the archival system when necessary. Patients and families were contacted directly for missing follow up data. Results: 143 different patients (61 males, mean age 50 years) underwent placement of 311 dialysis catheters via the common femoral vein (right⫽217). The only or last catheter placed was still functioning or lost to follow up in 7 patients. The primary patency was 66.5 catheter days (range 0-404). 100 catheters were exchanged over a guidewire (range 1-9/catheter), largely for nontract infection (46%) or poor catheter function (47%). The mean secondary catheter patency was 105 catheter days (range 0-711). Catheters were removed largely due to infection (50%), presence of a functioning arteriovenous access (30%) or were still in place at the time of patient demise (14%). In total, the infection rate was 7.4 per 1000 catheter days. 77 patients had one or more sonographic studies of the ipsilateral lower extremity while the catheter was in place. 18% were positive for deep venous thrombosis (DVT) but only 2 catheters required removal solely for DVT. There were 12 (4%) placement complications, 6 related to bleeding, there were no deaths. Conclusion: Dialysis catheters can be safely placed via the femoral vein but have a rather brief patency interval even in the face of frequent interventions designed to prolong catheter lifetime.

8:08 AM

Abstract No. 89

Translumbar hemodialysis catheters in patients with limited central venous access— does size matter? G. Nadolski, S. Trerotola, M.C. Soulen, M. Itkin, J. Mondschein, W. Stavropoulos, C. Farrelly; Hospital of the University of Pennsylvania, Philadelphia, PA

8:16 AM

Abstract No. 90

Failure to mature hemodialysis access fistulas: a 3-step approach to successful salvage R.N. Razdan, M. Zorzanello, M. Arici, E. Reiner, H.R. Mojibian, J. Pollak, J.E. Aruny; Vascular and Interventional Radiology, Yale University School of Medicine, New Haven, CT Purpose: To show the safety and efficacy of endovascular interventions for native hemodialysis access fistulas that fail to mature. Materials and Methods: A retrospective analysis of 36 patients was performed in subjects with primary failure of upper extremity hemodialysis access fistulas. The majority of the patients were first evaluated within 3 months of fistula creation after clinical evaluation by attending nephrologists determined the fistula could not be cannulated. Each patient underwent a three step algorithm to maximize treatment efficacy: 1. Maximize fistula diameter to at least 3 mm, coil embolize any accessory vessels, and treat stensoses. 2. Finish coiling of accessory vessels and

MONDAY: Scientific Sessions

T.P. Smith, C.Y. Kim, G. Janas, M.J. Miller, P. Suhocki, D.R. Sopko; Department of Radiology, Duke University Medical Center, Durham, NC

Purpose: To describe a single institution’s experience with translumbar hemodialysis catheters (THCs) and compare outcomes and complications between patients with normal body mass index (BMI) and those who are overweight (BMI⬎25). Materials and Methods: An IRB approved, HIPAA compliant retrospective review of all THCs placed between January 2002 and July 2011 was performed. In all, 33 patients (mean age 51.4 yrs, 51.5% male, 18 normal BMI, 15 BMI⬎25) were included. All had central venous occlusion preventing catheter placement in an internal or external jugular vein. Technical outcome, complications, indications for exchange/removal, and BMI were recorded. Mean catheter dwell time, cumulative access site duration, catheter related thrombosis and infection rates were calculated. Results: A total of 92 THC procedures were included for analysis (39 initial placements, 53 exchanges) with a total of 7825 catheter days. All were split tip catheters. Technical success rate was 100%. A total of 2 minor (2.2%) and 3 major (3.3%) complications occurred. Two (1 minor, 1 major) occurred in patients with normal BMI while three (1 minor, 2 major) occurred in those with BMI⬎25 (p⫽NS). Indication for exchange/removal (N⫽78) included catheter related infection (N⫽39, 50.0%), malposition (N⫽15, 19.2%), catheter malfunction/occlusion (N⫽10, 12.8%), mature permanent vascular access (N⫽7, 9.0%), conversion to peritoneal dialysis (N⫽3, 3.9%), functioning transplant (N⫽2, 2.6%), malfunction and infection (N⫽1, 1.3%) and unknown (N⫽1, 1.3%). Three THCs remained in use at the time of review. Nine patients died, and two were lost to follow up. Mean catheter dwell time for all, normal BMI and BMI⬎25 was 86.9⫾74.9, 86.1⫾67.8 and 87.8⫾81.9 days respectively (p⫽NS). Mean cumulative access site duration for all, normal BMI and BMI⬎25 was 257.0⫾343.7, 216.7⫾243.4 and 309.8⫾448.5 days, respectively (p⫽NS). Catheter related central venous thrombosis rate was 0.01 per 100 catheter days (N⫽1). Catheter associated infection rate was 0.51 per 100 catheter days (N⫽40). Conclusion: THC placement is safe and offers an effective route for hemodialysis in patients with limited venous access options. BMI does not affect the efficacy or the complication rate of THCs.

MONDAY: Scientific Sessions

S40 䡲 Monday

Scientific Session 䡲 JVIR

maximize fistula diameter to 6 mm. 3. Optimize system with repeat coiling or angioplasty with special attention to the arterial inflow/ anastomosis. Date of fistula creation, type of fistula created, location of stenoses within the circuit, method of angioplasty and/or stenting, method of embolization were all recorded. Endpoints were defined as successful cannulation, absence of complications and hemodialysis successfully performed through the intervened fistula. Results: 37 upper extremity fistulas in 36 patients ranging from 20-78 years of age. Two of the patients were evaluated twice because a second fistula was created and also failed to mature. 14 Males and 22 Females were included in the study of which 22 Fistulas had been placed in the left upper extremity and 15 fistulas placed in the right upper extremity. 17 Fistulas were Radiocephalic, 13 were brachio-cephalic, and the remaining 7 were brachio-basilic. 3 of the patients died. 24 out of 37 fistulas reached a successful endpoint (64%). Conclusion: Using this three step process we safely achieved successful cannulation and subsequent successful hemodialysis through the majority of nonmature arteriovenous fistulas.

8:24 AM

Abstract No. 91

Angioplasty of communicating veins to the brachial vein in hemodialysis patients with obliterated superficial veins of the upper arm E. Kim, J. Won, J. Kim, J. Bae; Radiology, Ajou University School of Medicine, Suwon-si, Republic of Korea Purpose: It is a challenge to recanalize near totally obliterated upper arm superficial veins in failing hemodialysis fistula. In this setting, the communicating vein to the brachial vein may be an alternative draining pathway, the largest one located in the antecubital fossa. Angioplasty of the communicating vein can relief pent-up pressure and establish flow for hemodialysis. The outcomes of angioplasty of the communicating veins when upper arm superficial veins are near totally obliterated in hemodialysis patients are evaluated. Materials and Methods: Twenty-two angioplasties of communicating veins performed for failing hemodialysis fistulas with near totally obliterated upper arm superficial vein from December 2006 to March 2011 were retrospectively reviewed. Fistulas were native radiocephalic (n⫽17), native brachiocephalic (n⫽3), radioantecubital graft (n⫽1) and brachio-antecubital U-graft (n⫽1). All angioplasties were performed using 5-8mm conventional balloons. Cutting balloon angioplasty was added in 5, and stent was inserted in 1 patient. The primary and secondary patency was calculated using Kaplan-Meier analysis. Results: The communicating vein was in the antecubital fossa (n⫽17) or upper arm (n⫽5). Technical and clinical success rates were 100% and 91%, respectively. Follow-up duration was 1 to 40 months (mean, 17 months). Median primary patency was 11 months. The primary patency rates at 3, 6 and 12 months were 80.1%, 60.2% and 49.8%, and the secondary patency rates at 3, 6 and 12 months were 94.4%, 88.1% and 74.6%. There was no major nor minor complication. Conclusion: Angioplasty of the communicating vein is effective in restoring function of failing hemodialysis fistula with obliterated superficial veins of the upper arm.

8:32 AM

Abstract No. 92

Non-laminar flow and low wall shear stress in arteriovenous access grafts correlate with pressure differences: a computational fluid dynamics study C. Karmonik1,2, J. Bismuth1, J.E. Anaya-Ayala1, C.A. Duran1, D.J. Shah1, S.H. Little1, M.G. Davies1, A.B. Lumsden1; 1Department of Surgery, Methodist DeBakey Heart and Vascular Center, Houston, TX; 2 Methodist Neurological Institute, Houston, TX Purpose: Anastomotic stenosis represents is a major complication in vascular access grafts in the hemodialysis population. Disturbed non-linear flow patterns and consequently low wall shear stress may promote conditions favorable for intimal hyperplasia. To test this hypothesis, computational fluid dynamics (CFD) simulations varying pressure conditions on venous and arterial site were performed to create virtual scenarios for a better understanding of the influence of venous and arterial stenosis on intragraft flow conditions. Materials and Methods: A virtual model of an arteriovenous access graft was created consisting of 28,463 tetrahedral elements. Three scenarios were simulated: #1) zero pressure resistance at arterial and venous site (venous stenosis), #2) zero pressure resistance at arterial outflow,additional inflow of 0.2 m/sec from venous site (patent arterial and venous sites) #3)pressure resistance of 700 Pa at arterial outflow (distal arterial stenosis), zero pressure at venous site. Inflow for all three scenarios was 1 m/sec. Velocity patterns and walls shear stress values were determined at the anastomosis site. Results: In scenario #1, a large region of low WSS (⬍ 2 Pa) was observed at the anastomosis arterial site consistent with clinical reports describing the location of outflow stenosis. In scenario #2, this region essentially disappeared but was enlarged in scenario #3. Comparison of flow patterns revealed recirculating flow adjacent to low WSS regions in scenario #1 and #3. Inflow from venous site in scenario #2 in contrast stabilized desired flow pattern resulting in ordered laminar flow from inflow to arterial outflow. Conclusion: This study demonstrates that CFD can help understand flow patterns in vascular access grafts by varying pressure and inflow conditions in a virtual environment. Stenosis of venous site (no venous inflow, scenario #1) or restricted arterial outflow (scenario #3) result in degradation of ideal flow pattern (scenario #2) leading to low WSS and flow recirculation potentially promoting intimal hyperplasia, poor function and failure of the access graft.

8:40 AM

Abstract No. 93

Does uremia predict AVF patency failure? R. Pannu, S. Misra; Interventional Radiology, St. Lukes Roosevelt Hospital, NYC, NY Purpose: The one-year primary patency failure rate for hemodialysis (HD) arterial-venous fistulas (AVF) in end stage renal disease (ESRD) remains unacceptably high at ⬃50%. Animalmodel studies suggest that uremia contributes to AVF patency failure. Objective of this retrospective cohort study, is to test uremia as a predictor of AVF patency failure. Materials and Methods: By chart review, Mayo Clinic ESRD patients with AVF for HD (n⫽8) and severely hyperlipidemic patients with AVF for low-density lipoprotein (LDL) apheresis