Predictors of outcome for renal artery stenting performed for salvage of renal function.
Modrall JG, Timaran CH, Rosero EB, Chung J, Arko FA 3rd, Valentine RJ, Clagett GP, Trimmer C.
J Vasc Surg. 2011 Jul 30.
Abstract
OBJECTIVE:To identify preoperative clinical features that predict a durable improvement in renal function with renal artery stenting (RAS). METHODS:Sixty-one patients with renal insufficiency (serum creatinine ≥1.5 mg/dL) underwent RAS for renal salvage. Patients were categorized as "responders" if estimated glomerular filtration rate (eGFR) at last follow-up was improved 20% or more over baseline. Patients with stable or worse renal function after RAS were labeled "non-responders." For the purpose of calculating changes in eGFR, patients on dialysis were represented by an eGFR of 10 ml/min/1.73 m(2). Renal volume was estimated as kidney length × width × depth/2.
RESULTS: The median age of the cohort was 66 years (interquartile range [IQR], 60-73 years). Median preoperative serum creatinine was 1.8 mg/dL (IQR, 1.6-2.3), and median estimated glomerular filtration rate (eGFR) was 34 mL/min/1.73 m(2) (IQR, 24-45). With stenting, 17 of 61 patients (27.9%) derived a durable improvement in renal function at a median follow-up of 24 months (IQR, 16-33 months). The largest proportion of stented patients (44.3%) had no improvement in renal function after stenting, while a subset (27.9%) experienced a decline in renal function. Responders enjoyed a 47% improvement in renal function from baseline, while non-responders had a 13% decrement in renal function (P < .0001). Responders had a higher baseline serum creatinine, lower eGFR, and a steeper decline in renal function prior to RAS, compared with non-responders. Kidney length, width, depth, and volume were not significantly different between responders and non-responders. Logistic regression analysis identified the rate of decline of renal function prior to stenting as the only independent preoperative predictor of improved renal function after RAS (odds ratio, 3.4; 95% confidence interval, 1.6 to 7.5; P = .0019). The rate of decline in eGFR per week was more than 20-fold greater for responders than non-responders (2.1% vs 0% decline in eGFR per week; P < .0001). No predictors of renal function deterioration after stenting were identified. CONCLUSIONS:The current study found that a steep decline in preoperative renal function portends a higher likelihood of renal salvage from RAS among patients with renal insufficiency. Incorporating this finding into patient selection may improve outcomes for RAS.
Basilic vein transposition versus biosynthetic prosthesis as vascular access for hemodialysis.
Morosetti M, Cipriani S, Dominijanni S, Pisani G, Frattarelli D, Bruno F.
J Vasc Surg. 2011 Jul 29.
Abstract
BACKGROUND:Vascular access (VA) complications account for a significant number of hospital admissions in dialysis and have substantial costs. A native arteriovenous fistula (AVF) cannot be successfully obtained in all patients. At our center, we established an autogenous brachial-basilic AVF (BBAVF) in the upper arm in patients with a failed forearm fistula or with superficial vessels that were unsuitable for preparing a good site for VA. In most of these patients, we resort to prosthetic materials for creating a functioning VA as the last strategy. The present study compared the outcomes of BBAVF and AV graft (AVG) in patients undergoing long-term hemodialysis in whom there was no other possibility of creating a VA. METHODS: We analyzed 57 complex patients, 27 randomized to receive AVG and 30 randomized to BBAVF, between 2002 and 2008. The Omniflow II Vascular Prosthesis (Bio Nova International Pty Ltd, North Melbourne, VIC, Australia), the latest-generation collagen-polyester composite, was used to create the prosthetic VA. Primary patency (PP) and secondary patency (SP) rates were calculated using the Kaplan-Meier test. The log-rank test was used to compare PP and SP rates of the single VA.
RESULTS: Length of hospital admission time, total intervention time, and mean interval to the first venipuncture for dialysis were longer for BBAVF. In the early postoperative period, patients who received BBAVF had a complication rate similar to those who received AVG; however, patients who received AVG showed a higher rate of long-term adverse events. PP and SP rates were higher for BBAVF than for AVG, although this was not statistically significant for SP. CONCLUSIONS: Our results show that BBAVF should be the first choice in patients with a good life expectancy and who can rely on an available temporary VA. However, given the shorter time to use, AVG could be an alternative in patients with compromised clinical conditions and in whom a temporary VA is not reliable, considering that the long-term outcome may be considered beneficial regardless.
Jones RG, Willis AP, Jones C, McCafferty IJ, Riley PL.
J Vasc Interv Radiol. 2011 Jul 16.
Abstract
PURPOSE: To determine the effectiveness of stent-grafts for the treatment of central venous disease in hemodialysis patients with functioning arteriovenous (AV) fistulas. MATERIALS AND METHODS: Between October 2004 and March 2010, 42 VIABAHN stent-grafts were deployed in central veins of 30 patients (16 men, 14 women; mean age 60 y) with functioning AV fistulas and central venous disease that did not respond to percutaneous transluminal angioplasty (PTA). Eighteen patients had central vein stenosis and 12 had occlusion. Previous PTA and/or bare metal stent placement had been performed in 23 patients (77%). Surveillance was carried out at 3, 6, 9, 12, 18, and 24 months with diagnostic fistulography. The mean follow-up was 705 days (range, 66-1,645 d). Statistical analysis included Kaplan-Meier and log-rank studies. RESULTS: Technical success rate was 100%. Primary patency rates were 97%, 81%, 67%, and 45% at 3, 6, 12, and 24 months, respectively. Primary assisted patency rates were 100%, 100%, 80%, and 75% at 3, 6, 12, and 24 months, respectively. Patients without previous procedures had significantly shorter times to repeat intervention (P = .018) than those who had undergone PTA or bare metal stent placement previously. Patients with occlusive lesions had a significantly shorter primary patency interval (P = .05) than patients with stenoses. Occluded veins were more likely to require further stent-grafts (P = .02). Twelve patients required further stent-grafts to maintain patency. There was one minor complication.
CONCLUSIONS: Stent-graft placement to treat central venous disease in hemodialysis patients with autogenous AV fistulas is safe and effective if PTA fails to maintain luminal patency.
Management of true aneurysms of hemodialysis access fistulas.
Pasklinsky G, Meisner RJ, Labropoulos N, Leon L, Gasparis AP, Landau D, Tassiopoulos AK, Pappas PJ.
J Vasc Surg. 2011 May;53(5):1291-7.
Abstract
OBJECTIVES: This study was designed to determine the clinical presentation, characteristics, and management of true aneurysms in dialysis access fistulas. METHODS: Patients presenting with symptoms or functional arteriovenous fistula (AVF) problems and aneurysmal enlargement of the outflow vein were evaluated with duplex ultrasound scans. Dilatation to more than three times the native vessel diameter was considered aneurysmal. Pseudoaneurysms were excluded from the study. Patients' demographics, aneurysm characteristics (diameter, location, thrombus, association with stenosis, and outflow obstruction), symptoms, type of treatment, and follow-up were recorded. RESULTS: Twenty-three patients with a mean age of 55 years were found to have 29 upper extremity aneurysms of the outflow vein on duplex ultrasound scan. Nine patients (39%) had radiocephalic, 11 patients (48%) had brachiocephalic, 2 patients (9%) had brachiobasilic, and 1 patient (4%) had radiobasilic arteriovenous fistula. The average aneurysm size was 3.3 cm and the mean time from fistula placement to treatment was 47.1 months. Four patients (17%) were asymptomatic and were repaired due to technical and mechanical problems with AVFs, including stenosis and lack of normal vein for cannulation, compromising continued use. Nineteen patients (83%) presented with symptoms, including pain (48%), skin changes (30%), venous hypertension (22%), steal syndrome (22%), and high output failure (9%). Four patients (17%) were found to have outflow vein stenosis, 2 patients (9%) had central venous stenosis, and 2 patients (9%) had central venous occlusion. In 13 patients (56%) who had a functioning kidney transplant, the fistula was ligated with or without aneurysm excision. Three of the 13 patients developed superficial phlebitis with 1 patient requiring surgical evacuation of a clot; the other 2 patients were managed conservatively. Two of the 13 patients required creation of new access due to renal transplant failure. In the remaining 10 patients, the aneurysm was treated and the fistula salvaged due to a persistent need for hemodialysis. The median follow-up of these patients was 19 months ranging from 8 to 25 months. Seven patients (30%) underwent excision and repair with the great saphenous vein and 3 patients (13%) had excision and repair with prosthetic material, 2 of which underwent central venous angioplasty and stenting. Two patients developed thrombosis of their repair requiring new access in the contralateral arm. Three patients needed secondary percutaneous interventions for anastomotic stenosis. CONCLUSION: Although true aneurysms in patients with dialysis access are uncommon, significant complications may occur as a consequence of their presence. These complications can be treated and the fistulas can usually be salvaged.
Tebbi C, Costanzi J, Shulman R, Dreisbach L, Jacobs BR, Blaney M, Ashby M, Gillespie BS,Begelman SM.
J Vasc Interv Radiol. 2011 Aug;22(8):1117-23.
Abstract
PURPOSE: To evaluate, in a phase III, single-arm study, the safety and efficacy of the thrombolytic agent tenecteplase in restoring function to dysfunctional central venouscatheters (CVCs). MATERIALS AND METHODS: Pediatric and adult patients with dysfunctional CVCs were eligible to receive as much as 2 mL (2 mg) of intraluminal tenecteplase, which was left to dwell in the CVC lumen for a maximum of 120 minutes. If CVC function was not restored at 120 minutes, a second dose was instilled for an additional 120 minutes. RESULTS: Tenecteplase was administered to 246 patients. Mean patient age was 44 years (range, 0-92 y); 72 patients (29%) were younger than 17 years of age. Chemotherapy was the most common reason for catheter insertion. Restoration of CVC function was achieved in 177 patients (72%) within 120 minutes after the first dose. After instillation of a maximum of two doses of tenecteplase, CVC function was restored in 200 patients (81%), with similar frequencies in pediatric (83%) and adult (80%) patients. Adverse events (AEs) were reported in 31 patients (13%); fever (2%), neutropenia (1%), and nausea (0.8%) were most common. One serious AE, an allergic hypersensitivity reaction, was judged to be related to tenecteplase and/or a chemotherapeutic agent that the patient was receiving concurrently. CONCLUSIONS: Consecutive administration of one or two doses of tenecteplase into CVCs showed efficacy in the restoration of catheter function in patients with dysfunctional CVCs
Arteriovenous Graft Placement in Predialysis Patients: A Potential Catheter-Sparing Strategy
Roman Shingarev, MD,1 Ivan D. Maya, MD,1 Jill Barker-Finkel, PhD,2 and
Michael Allon, MD1
Am J Kidney Dis. 58(2):243-247. © 2011 by the National Kidney Foundation, Inc.
Background: When predialysis patients are deemed unsuitable candidates for an arteriovenous fistula, current guidelines recommend waiting until just before or after initiation of dialysis therapy before placing a graft. This strategy may increase catheter use when these patients start dialysis therapy. We compared the outcomes of patients whose grafts were placed before and after dialysis therapy initiation. Study Design: Retrospective analysis of a prospective computerized vascular access database. Setting & Participants: Patients with chronic kidney disease receiving their first arteriovenous graft (n _ 248) at a large medical center. Predictor: Timing of graft placement (before or after initiation of dialysis therapy). Outcome & Measurements: Primary graft failure, cumulative graft survival, catheter dependence, and catheter-related bacteremia. Results: The first graft was placed predialysis in 62 patients and postdialysis in 186 patients. Primary graft failure was similar for pre- and postdialysis grafts (20% vs 24%; P _ 0.5). Median cumulative graft survival was similar for pre- and postdialysis grafts (365 vs 414 days; HR, 1.22; 95% CI, 0.81-1.98; P _ 0.3). Median duration of catheter dependence after graft placement in the postdialysis group was 48 days and was associated with 0.63 (95% CI, 0.48-0.79) episodes of catheter-related bacteremia per patient. Limitations: Retrospective analysis, single medical center. Conclusion: Grafts placed predialysis have primary failure rates and cumulative survival similar to those placed after starting dialysis therapy. However, postdialysis graft placement is associated with prolonged catheter dependence and frequent bacteremia. Predialysis graft placement may decrease catheter dependence and bacteremia in selected patients.
Original Article
Bogdan Ene-Iordache1 and Andrea Remuzzi1,2
1Department of Biomedical Engineering, Laboratory of Biomedical Technologies, Mario Negri Institute for Pharmacological Research,
Ranica, Italy and 2Department of Industrial Engineering, University of Bergamo, Dalmine, Italy
Correspondence and offprint requests to: Bogdan Ene-Iordache; E-mail:bogdan@marionegri.it
Nephrol Dial Transplant (2011) 0: 1–11
doi: 10.1093/ndt/gfr342
Abstract
Background. Despite recent clinical and technological advancements, the vascular access (VA) for haemodialysis still has significant early failure rates after arteriovenous fistula (AVF) creation. VA failure is mainly related to the haemodynamic conditions that trigger the phenomena of vascular wall disease such as intimal hyperplasia (IH) or atherosclerosis. Methods. We performed transient computational fluid dynamics simulations within idealized three-dimensional models of ‘end-to-side’ and ‘end-to-end’ radio-cephalic anastomosis, using non-Newtonian blood and previously measured flows and division ratio in subjects requiring primary access procedure as boundary conditions. Results. The numerical simulations allowed full characterization of blood flow inside the AVF and of patterns of haemodynamic shear stress, known to be the major determinant of vascular remodelling and disease. Wall shear stress was low and oscillating in zones where flow stagnation occurs on the artery floor and on the inner wall of the juxta-anastomotic vein. Conclusions. Zones of low and oscillatory shear stress were located in the same sites where luminal reduction was documented in previous experimental studies on sites stenosis distribution in AVF. We conclude that even when exposed to high flow rates, there are spot regions along the AVF exposed to athero-prone shear stress that favour vessel stenosis by triggering IH.
Eduardo Lacson Jr, MD, MPH, Weiling Wang, MS, Cari DeVries, Keith Leste, MA,
Raymond M. Hakim, MD, PhD, Michael Lazarus, MD, and Joseph Pulliam, MD
Am J Kidney Dis. 58(2):235-242. © 2011 by the National Kidney Foundation, Inc.
Background: Patients’ education about transplant, hemodialysis (HD), peritoneal dialysis (PD), and conservative care often is provided by nephrologists as needed and occurs as time allows. Study Design: Quality improvement report. Setting & Participants: Attendees of a national treatment options program (TOPs) who initiated long-term dialysis therapy (median, 3.4 months) at Fresenius Medical Care, North America facilities throughout 2008 were compared with period-prevalent incident patients receiving usual care. Quality Improvement Plan: Standardized predialysis treatment options education. Outcomes: Rates of opting for PD modality, arteriovenous HD access at initiation, and early (90-day) mortality risk. Measurements: Logistic regression (for choice of PD and HD access type) and Cox models (for early mortality) were constructed, including a 1:1 matched cohort. A post hoc sensitivity analysis also compared a propensity score–matched cohort. Results: 3,165 TOPs attendees (10.5% of 30,217 incident patients admi tted between January 1 and December 31, 2008), were younger, more likely to be white, and had slightly larger body surface area. The unadjusted OR for TOPs attendees for selecting PD therapy was 8.45 (95% CI, 7.63-9.37) with a case-mix plus laboratory–adjusted OR of 5.13 (95% CI, 3.58-7.35). For patients who opted for in-center HD therapy, the OR was 2.14 (95% CI, 1.96-2.33) and adjusted OR was 2.06 (95% CI, 1.88-2.26) for starting with a fistula or graft. The unadjusted early mortality HR was 0.51 (95% CI, 0.43-0.60) and case-mix plus laboratory–adjusted adjusted HR was 0.61 (95% CI, 0.50-0.74) for TOPs attendees (all outcomes, P _ 0.001). These results were consistent in the 1:1 matched analysis and propensity score–matched analysis. Limitations: It is possible that physicians who referred to these programs were more likely to prescribe PD therapy or place arteriovenous accesses. Motivated, treatment-adherent patients (who would have better outcomes) may have self-selected to attend education sessions. Conclusion: Attending an options class predialysis was associated with more frequent selection of home dialysis, fewer tunneled HD catheters, and lower mortality risk during the first 90 days of dialysis therapy.
Improving Incident Fistula Rates: A Process of Care Issue
Editorial - AJKD
Am J Kidney Dis. 2011;57(6):814-817