Nonfunctioning Arteriovenous Fistula Research Articles

Epithelioid angiosarcoma at a non-functioning arteriovenous fistula site in a renal transplant patient.

We present a case of biopsy-proven epithelioid angiosarcoma in an arteriovenous fistula (AVF). Angiosarcomas developing in non-functioning AVF in renal transplant recipients are rare clinical entities with poor prognosis. A 59-year-old male adequately immunosuppressed kidney transplant patient presented with pain and swelling at the site of a previously asymptomatic fistula. A duplex scan confirmed the presence of thrombosis present along the length of the AVF; however, in light of worsening pain and skin changes, an MRI scan was requested. This demonstrated a thrombosed brachiocephalic AVF and a more sinister appearing irregular segment infiltrating the underlying anterior compartment musculature with associated muscle oedema and internal irregular enhancement. A staging CT thorax showed indeterminate lymphadenopathy in the left axilla with no pulmonary lesions. Core needle biopsy of the primary lesion at the fistula site and subsequent biopsy of the axillary lymph nodes revealed metastatic angiosarcoma. A multidisciplinary decision was made to perform radical surgery with above-elbow amputation and simultaneous left axillary lymph node clearance. We focus on relevant imaging findings to facilitate early recognition of angiosarcoma, in particular, the importance of requesting urgent imaging of vascular access sites (functioning or not) in post-transplant patients presenting with swelling. Although rare, angiosarcoma is an important entity that should be considered in the differential diagnosis of soft tissue masses arising from a vascular access, especially in immunocompromised patients.

Association of neutrophil-to-lymphocyte ratio and hemodialysis access failure in patients with end stage renal disease: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to assess the association of neutrophil-to-lymphocyte ratio (NLR) with an elevated risk of vascular access failure in end-stage renal disease (ESRD) patients undergoing hemodialysis. A comprehensive database search of MEDLINE (via PubMed), Scopus, and Cochrane Central was performed. Studies reporting the values of NLR in both functional and non-functional AVF groups in ESRD patients were selected. Quality assessment was performed using the Modified Newcastle-Ottawa scale for observational studies. Meta-analysis was performed using an inverse variance random effects model. Seven observational studies met the inclusion criteria, including 1313 participants with 554 cases and 759 controls. Pooled results showed significantly high NLR levels in patients with non-functional arteriovenous fistula (AVF) compared to functional AVF (SMD = 1.19, 95% CI = 0.74-1.65, p < 0.001). Subgroup analysis confirmed the consistency of the association between NLR and AVF failure across study design (SMD = 1.76, 95% CI = 0.78-2.73, p = 0.0004 in prospective vs SMD = 0.87, 95% CI = 0.42-1.32, p = 0.0001 in retrospective studies), etiology (SMD = 1.63, 95% CI = 0.75-2.52, p = 0.0003 in stenosis or thrombosis; and SMD = 0.80, 95% CI = 0.27-1.34, p = 0.003 in failure to mature of AVF), and NLR measurement timing (SMD = 0.98, 95% CI = 0.42-1.54, p = 0.0006 in preoperative vs SMD = 1.58, 95% CI = 0.47-2.69, p = 0.005 in postoperative NLR). The pooled odds ratio revealed high NLR values as a significant predictor of AVF failure in ESRD patients (OR = 3.91, 95% CI = 1.91-7.98, p = 0.0002). The pooled sensitivity and specificity were 89.72% (95% CI = 77.51%-95.67%) and 72.95% (95% CI = 63.82%-80.47%), respectively. The high NLR is a useful and predictive marker for AVF failure in hemodialysis patients. Future studies should prioritize larger cohort studies to validate and reinforce these observations.

#336 Early detection of vascular access complication in pediatric CKD hemodialysis patients

Abstract Background and Aims Vascular access (VA) dysfunction is a major clinical complication in the hemodialysis (HD) population and has a direct effect on dialysis outcome. Where in patients undergoing HD, neointimal hyperplasia results in vascular stenosis and subsequent thrombosis, which lead to vascular access failure. Interleukin-10 (IL-10), hs CRP, and tumor necrosis factor- (TNF–α) are inflammatory markers which are proved to be involved in the process neointimal hyperplasia &amp; subsequent complications. We aimed to evaluate the value of these inflammatory markers in early detection of arterio-venous fistula (AVF) failure, in pediatric patients on regular HD, together with the clinical &amp; radiological diagnoses, for proper intervention for correcting AVF failure according to guidelines. Method It was an prospective cohort study, where we included 59 pediatric chronic kidney disease patients’ stage 5, on regular HD (CKD5d), who were following up regularly with us for 1 year. Patients with nonfunctioning AVFs due to complications as thrombus occluding fistula, infections, or large aneurysm, were excluded from the beginning of the study. Monitoring of VA by pre-cannulation physical examination was performed to detect the physical signs of dysfunction, at least once per month according to KDOQI guidelines. Venous pressure (VP) and trans-membrane pressure (TMP) were recorded at each HD session, to detect any abnormalities and to record the pressure changes with the appearance of any AVF complications. Doppler ultrasound (DUS) was performed routinely every 3 months for all HD patients, &amp; at the time of development AVF complications. Blood samples for measuring IL10, TNF, hs CRP were collected from the patients every 2 weeks for 12 months, prior to HD sessions, where we included the most recent samples prior to, and at the time of development complications, which were clinically and radiologically confirmed. Results The mean (±SD) age of our patients was 13.97 (±2.65) years, where we had 39 (56.5%) males, and 30 (43.5%) females, with a median (IQR) HD duration of 4.0 (5.0) years. On assessing the AVF complications, 33 patients (55.9%) had experienced complications, where thrombosis was the most common reported one (17 patients, 28.8%), followed by aneurysm formation in 14 patients (23.7%), while 6 patients (10%) had stenosed AVF, early VA failure in 2 patients (3.4%),1 patient (1.7%) had pseudoaneurysm, and another patient (1.7%) had perivascular hematoma. Mean serum levels of Hs-CRP, TNF-α, IL-10 were elevated at timing of early development of complication, in comparison to their baseline levels, meanwhile serum IL10, and TNF alpha were significantly higher among patients who developed AVF stenosis. The baseline hs-CRP had related positively with AVF diameter at the time of the development of the complications. Conclusion The inflammatory markers have no clinically applied role in early detection of AVF abnormalities, therefore, physical examination and DUS are deemed sufficient.

Association of anesthetic modality and other variables on 1-year functional patency of cephalic-based arteriovenous fistulae

ObjectiveSome studies suggest that regional anesthesia provides better patency for arteriovenous fistula (AVF) for hemodialysis access as compared to local and general anesthesia. This study evaluates the impact of anesthetic modality on long term fistula function at 12 months. MethodsA retrospective review of patients undergoing cephalic vein-based hemodialysis access in consecutive cases between 2014 and 2019 was conducted from five safety net hospitals. The primary endpoint was functional patency at 12 months. Subset analysis individually evaluated cephalic-based lower forearm and wrist vs upper arm AVFs. Bivariate and multivariate logistic regression models evaluated the relationship between anesthetic modality and fistula function at 12 months. ResultsThere were 818 cephalic-based fistulas created during the study period. The overall 12-month functional patency rate was 78.7%, including an 81.3% patency for upper arm AVF and 73.3% for wrist AVF (P = .009). There was no statistically significant difference among patients with functional and nonfunctional AVFs at 12 months with respect to anesthetic modality when comparing regional, local, and general anesthesia (P = .343). Multivariate regression analysis identified that history of AVF/arteriovenous graft (odds ratio [OR], 0.24; P = .007), receiving intraoperative systemic anticoagulation (OR, 2.49; P < .001), and vein diameter (OR, 1.85; P = .039) as independently associated with AVF functional patency at 12 months. ConclusionsThere was no association between anesthetic modality and functional patency of cephalic-based AVFs at 12 months. Further studies are needed to better define which patients may benefit from regional anesthesia.

Factors associated with functional arteriovenous fistula at hemodialysis start and arteriovenous fistula non-use in a single-center cohort.

The gold standard of commencing hemodialysis with a functional arteriovenous fistula (AVF) is challenging. We aim to review factors associated with functional AVF at hemodialysis start at a tertiary hospital. We retrospectively reviewed incident hemodialysis patients or who had AVF creation at a single tertiary hospital from 2011 to 2016. Data was extracted for patient comorbidities, duration from referral to AVF creation and hemodialysis start, estimated glomerular filtration rate (eGFR) at surgical referral, referring nephrologist, events accelerating eGFR decline, and revisions for "failing to mature" AVF to assess factors associated with non-functioning AVF or late AVF creation, using multinomial logistic regression. Two hundred two patients received hemodialysis and 51 had AVF creation but did not dialyze (AVF futility rate 20%). Of these, 133 (66%) commenced hemodialysis with a central venous catheter (CVC) and 69 (34%) with an AVF. Patients with functional AVFs at hemodialysis start were referred earlier than those with non-functional AVFs (median 256 vs 66 days before hemodialysis start, p = 0.001). Age, sex, eGFR at surgical referral, and comorbidities were not predictive of patients with functional AVFs. Events accelerating eGFR decline were associated with an increased incidence of CVC at hemodialysis start (risk ratio (RR) 4.21, 95% confidence interval (CI) 1.96-9.03, p < 0.0001). Referring nephrologists external to our renal unit may be associated with non-functional AVF at hemodialysis start (RR 6.60, 95% CI 1.74-25.13, p = 0.006). We found that functional AVFs required referral a median of 256 days prior to hemodialysis start and events accelerating eGFR decline increase the incidence of CVC at hemodialysis start. Age, sex, eGFR at surgical referral, and comorbidities did not inform the likelihood of timely AVF creation and evaluation of further predictive pre-dialysis factors is necessary to identify patients requiring early AVF creation whilst minimizing the cost of unnecessary procedures.

Effect of the mean platelet volume/platelet count ratio on arteriovenous fistula function in chronic hemodialysis patients

ObjectiveThe aim was to study the effect of increased mean platelet volume/platelet count (MPV/PL count) on arteriovenous fistula (AVF) function in chronic hemodialysis (HD) patients.BackgroundVascular access failure substantially contributes to morbidity and hospitalization in HD patients.Patients and methodsA case–control study was conducted on 50 HD patients on regular HD for more than 6 months in Shebin El-Koom Teaching Hospital, Menoufia, Egypt. The patients were divided into two groups: 25 patients with functioning AVF as group 1 and 25 patients with nonfunctioning AVF as group 2. Patients were subjected to full history taking, clinical examination, laboratory workup, and radiology by Duplex ultrasound.ResultsThere was no significant effect of age, sex, BMI, diabetes mellitus, hypertension, smoking, or type of anastomosis on AVF in HD patients. There was a significant effect of intradialysis hypotension on AVF in HD patients. There was a highly significant effect of fistula function on Kt/V in HD patients. There was a highly significant increase of MPV/PL count ratio in HD patients with failure of AVF. MPV/PL count at a cut-off level of 53.7 can accurately predict failure of AVF in the studied HD patients with 100% sensitivity and 84% specificity.ConclusionAssessment of MPV/PC ratio could adequately predict the failure of the function of AVF in the studied patients.

P1343DOES “FISTULA FIRST” FITS TO ELDERLY?

Abstract Background and Aims The incident patients on hemodialysis (HD) are becoming older. However, the optimal type of initial permanent vascular access (VA) among the elderly is controversial. Patient comorbidities and life expectancy are important considerations in whether to place an arteriovenous fistula (AVF) or graft (AVG). We design an observational study to compare clinical outcomes of elderly (≥65 year old) versus younger patients, who underwent for first VA placement before initiation of renal replacement therapy, between January 2014 and December 2018. Method We evaluated successful use of VA, requirement of surgical interventions before successful use, VA in use after the first and third months on HD and clinical outcomes, until December 2019. The comorbidity burden was calculated through age-adjusted Charlson Comorbidity Index (aCCI). We also evaluated the impact of comorbidity burden on the VA type on HD start and mortality after HD initiation. Results We identified 252 predialysis patients who underwent for VA placement in our center. We created two groups based on age at the time of VA placement: there were 199 (79,0%) with age ≥ 65 years (the elderly group), and 53 (21,0%) younger patients. The elderly group presented a mean age of 76,3 ± 6,4 (maximum of 92) years on first VA placement; in the younger group, the mean age was 54,5 ± 9,1 (minimum of 26) years. The following analysis are presented for elderly versus younger group. On both groups there were a predominance of male gender (66,8%; 73,6%; p=0,498) and caucasian race (95,0%; 88,7%; p=0,193). At time of referral for AV placement, both groups presented similar mean estimated glomerular filtration rate by CKD-EPI equation (11,7 ± 3,2; 11,2 ± 3,2 mL/Kg/1,72m2; p=0,391). Elderly group presented a significant higher aCCI (7,3 ± 1,74; 9,0 ± 1,9; p&amp;lt;0,001). The groups were also different in smoking status (6,0%; 30,8%; p&amp;lt;0,001). There were no differences on kidney disease etiology between groups, with diabetes being the most prevalent (23,1%; 24,5%; p=0,856). For all patients, the first VA placed was AVF. Only two patient placed an AVG on second and third vascular accesses. The median number of VA placed were similar between the two groups [1,0 (1 to 4); 1,0 (1 to 2); p= 0,811], likewise the occurrence of early complications (9,5%; 5,7%; p=0,583) and the need for surgical interventions (46,7%; 47,2%; p=1,000). In both groups, the majority of patients started HD (80,4%; 90,6%; p=0,103), with similar successful use of the VA (68,1%; 75,0%; p=0,474). In multivariate logistic regression, proteinuria (measured at time of referral for AV placement) and heart failure (HF) were predictors to HD initiation through a central venous catheter (CVC). This model classified correctly 74,9% of cases, with an HF odds ratio (OR) of 4,149 [confident interval (CI) of 1,721 to 10,000] and a proteinuria OR of 1,148 (CI: 1,047 to 1,259). After the first month on HD, 34,8% of elderly patients needed a CVC, a number significantly different from the younger group (15,9%; p=0,023). The same result was observed after the third month (22,2%; 7,1%; p=0,028). During the time of follow-up, the mortality rate was higher in the elderly group who started HD (log Rank test = 0,004), with a median survival of 29,3 (0,1 to 89,8) months, when compared to the younger group [median survival of 38,3 (0,1 to 76,9) months]. Conclusion There were no difference in the kind of VA on HD start (definitive VA versus CVC) between the two groups. However, elderly patients presented more fistula failure in the first three months after HD initiation. The need of CVC due to nonfunctioning AVF on the first and three months after HD initiation was higher in the elderly. The analysis of the patients who started HD showed that the elderly group presented a significant reduced survival when compared to the youngest patients.

Role of peribrachial fat as a key determinant of brachial artery dilatation for successful arteriovenous fistula maturation in hemodialysis patients

The functional quality of the inflow artery is one of the most important determinants of arteriovenous fistula (AVF) success. We evaluated the association of early optimal brachial arterial dilatation with a successful AVF maturation and assessed the role of peribrachial adipose tissue in determining brachial arterial distensibility. All patients underwent a preoperative vascular mapping with Doppler ultrasound (US), and only patients who had suitable vessels for AVF creation were enrolled (n = 162). Peribrachial fat thickness was measured using US. To evaluate the degree of brachial dilatation, follow-up US was performed at 1 month after surgery, and early brachial artery dilation was defined as the change in postoperative arterial diameter compared to the preoperative value. The primary outcome was failure to achieve a clinically functional AVF within 8 weeks. Nonfunctional AVF occurred in 21 (13.0%) patients, and they had a significantly lower brachial dilatation than patients with successful AVF during early period after surgery (0.85 vs. 0.43 mm, p = 0.003). Patients with a brachial dilatation greater than median level showed a 1.8-times higher rate of achieving a successful AVF than those without. Interestingly, the early brachial dilatation showed significant correlations with diabetes (r = −0.260, p = 0.001), peribrachial fat thickness (r = −0.301, p = 0.008), and the presence of brachial artery calcification (r = −0.178, p = 0.036). Even after adjustments for demographic factors, comorbidities, and baseline brachial flow volume, peribrachial fat thickness was an independent determinant for early brachial dilatation (β = −0.286, p = 0.013). A close interplay between the peri-brachial fat and brachial dilatation can be translated into novel clinical tools to predict successful AVF maturation.

Arteriovenous fistulae for access to hemodialysis in Chad: feasibility study of a medical civic action program by a French army surgical unit.

Use of chronic intermittent hemodialysis is recent in Chad, where it remains underdeveloped. Vascular access is most commonly by catheter. The objective of our study was to demonstrate the feasibility of arteriovenous fistula (AVF) surgery for hemodialysis during deployments as part of the medical civic action program (MEDCAP). We prospectively included all patients admitted for AVF creation at Camp Kossei forward surgical unit in N'Djamena (Chad) between December 2016 and February 2017. Surgery was performed by an experienced vascular surgeon. The data collected included age, sex, cause of kidney failure, type of anesthesia, AVF location, and the duration of the intervention and hospitalization. Patients were examined one month after the procedure to evaluate the functionality, morbidity, and mortality of the AVF. We performed 17AVF in 3months. Male to female ratio was 3. High blood pressure was the main cause of chronic kidney failure (55%). All interventions were conducted under locoregional anesthesia. Overall, 35% of fistulae were radiocephalic, 41% brachiocephalic, and 24% brachiobasilic. The mean duration of intervention was 58minutes and that of hospitalization one day. No deaths occurred. Global morbidity, including non-functioning AVF, was 25%. Our study showed that AVF surgery is feasible during deployment, especially in Chad, and meets the needs of the local healthcare facilities. It should be developed and taught to local surgeons.

Planning Vascular Access in Peritoneal Dialysis-Defining High-Risk Patients.

Peritoneal dialysis (PD) is an effective renal replacement technique. However, every year a considerable number of patients are transferred to hemodialysis (HD). Our aim was to identify those at risk, in order to place an arteriovenous fistula (AVF). Case-control study enrolling all prevalent patients in 2014 and 2015 in our clinic. Groups: 72 case patients who were transferred definitively to HD, 111 control patients (remaining on PD, transplanted, recovered renal function, or deceased). A total of 183 patients were eligible, with a mean age of 55.2 ± 14.8 years, 56.3% male, 31.1% diabetic, and 49.7% on continuous ambulatory PD. The mean follow-up time was 42.1 ± 25.6 months. Eighty-five patients had an AVF. The groups differed in diabetic nephropathy etiology, and in some PD-related characteristics (Kt/V, creatinine clearance, residual renal function, mean ultrafiltration, natriuretic peptide, peritonitis, hospitalizations, and hypervolemia). In multivariate analysis, Kt/V < 1.7 (odds ratio [OR] 3.00, 95% confidence interval [CI]: 1.20 - 7.50], albumin < 35 g/L (OR 4.03, 95% CI: 1.26 - 12.92), number of hospitalizations 1 to 3 (OR 2.74, 95% CI: 1.15 - 6.53) and 4 or more (OR 10.48, 95% CI: 3.62 - 30.36), and 2 or more peritonitis episodes (OR 2.50, 95% CI: 1.03 - 6.07) were predictors of PD transfer to HD. In those patients who were transferred to HD, 34 initiated HD by AVF, 2 needed a catheter due to a non-functioning AVF, and 36 did not have an AVF needing catheter placement. Low Kt/V, low albumin, higher number of hospitalizations, and peritonitis were factors associated with PD transfer to HD, probably indicative of a high-risk PD population where arteriovenous access should be weighed.

Comparison of Efficacy of Side to Side Versus End to Side Arteriovenous Fistulae Formation in Chronic Renal Failure as a Permanent Hemodialysis Access

BackgroundIn candidate patients for permanent hemodialysis or dialysis on a regular basis, an appropriate vascular access has great importance. The best permanent access is AVF (arterio venous fistula). Use of a technique to create AVF with better patency seems to be logical.ObjectivesThe present study aimed to compare the efficacy rate of AVFs using two different anastomosis methods; Side to Side (STS) versus End to Side (ETS) and to determine whether the different approaches render any preferences or complications.Patients and MethodsSixty end stage renal disease (ESRD) patients were included in this clinical trial in two assigned groups of 30 patients. In one group end to side method to create AVF was used while in the other group Side to Side technique was applied for access in surgery. Both groups were followed for duration of 6 months to assess patency. For evaluating the quantitive variables, t-test was used while qualitative variables were measured using the chi-square and Fisher`s exact tests.ResultsIn the 6 months duration, 6 patients (20%) in the STS (side to side) group and 5 patients (16.6%) in the ETS (end to side) group experienced a non-functional AVF. In the ETS group the failure was generally a result of thrombosed access while in the STS group, 4 out of 6 patients with complications, experienced thrombosis while the other 2 patients had venous hypertension. The total failure rate was 18.3% and during the 6 months of follow up no significant difference was detected in the efficacy rate. Nevertheless, in case of longer follow ups, different outcomes could be seen.ConclusionsThis study demonstrated that there was no significant statistical difference between the functional patency rates of fistulae placed by STS or ETS methods.

Évaluation des complications infectieuses liées aux cathéters veineux centraux d’hémodialyse en Polynésie française

The arterio-venous fistula (AVF) is the most common vascular access to perform hemodialysis (HD). The HD venous central catheter use should only be proposed to old patients and/or patients without vascular access construction feasibility. These HD catheters are often responsible of infectious and thrombosis complications. We performed, for the first time in French Polynesia, a retrospective study based on 214 patients receiving 618 HD catheters, to evaluate the infectious complication rate due to HD catheters. We showed that 17.4% of HD catheters present with infection. The number of bacteraemia due to HD catheters is 2.57/1000 days-catheters and the number of infection due to HD catheter is 1.43/1000 days-catheters. Eighteen percent of patients requiring an emergency HD without AVF access are transferred in intensive care unit due to infectious HD catheter complications. We observed a similar bacteriological environment than in literature. However, the number of tunneled HD catheter is really lower to that of the number required in European recommendations and we observed an abnormal number of non-functional AVF 1month after creation. These results involve our nephrology unit to increase the number of tunneled catheters to limit the infectious risk and also to fit with the best practices guidelines.

Functional Status of Hemodialysis Arteriovenous Fistula in Kidney Transplant Recipients as a Predictor of Allograft Function and Survival

There is no accepted policy for preserving or ligating arteriovenous fistula (AVF) after successful kidney transplantation. The aim of this study was to compare kidney graft function and survival between patients with a functional AVF at 1 year after-transplantation with those having a nonfunctional AVF. This historical cohort study included 311 kidney transplant recipients between January 2000 and December 2008 with a functional AVF at the time of transplantation. Patients were divided into 2 groups according to functional status of AVF at 1 year after transplantation. Graft function was assessed at 1 year by serum creatinine and estimated glomerular filtration rate (eGFR) using the 4-variable Modification of Diet in Renal Disease formula. Kaplan-Meier and Cox proportional hazards analyses were used to assess the relationship between the functional status of the AVF and graft survival. The 311 recipients had a mean age of 47 ± 11 years (range, 14 to 70) with 188 (60.5%) males. Patients with functional AVF at 1 year (n = 239) showed higher serum creatinine and lower eGFR values than those with nonfunctional AVF (n = 72): namely 110 ± 38 μmol/L and 69 ± 21 mL/min/1.73 m 2 versus 99 ± 30 μmol/L and 74 ± 19 mL/min/1.73 m 2, respectively ( P < .05). Persistence of a functional AVF at 1 year after transplantation was associated with a greater incidence of eGFR <60 mL/min/1.73 m 2 compared with nonfunctional AVF: 36.8% versus 23.6% (odds ratio, 1.885; 95% confidence interval [CI], 1.031–3.450; P = .038). The 5-year allograft survival rates were 60% among patients with a functional AVF versus 75% among those with a nonfunctional AVF ( P = .045). The adjusted analyses revealed the persistence of a functional AVF to be associated with an increased risk for future allograft loss (hazard ratio, 1.336; 95% CI, 1.018–1.755; P = .037). In conclusion, the persistence of a functional AVF was associated with a lower eGFR at 1 year after-transplantation and an increased risk for future allograft loss.

Forearm Venous Distensibility Predicts Successful Arteriovenous Fistula

The success of a newly created arteriovenous fistula (AVF) depends on sufficient maturation of the forearm vein used. This maturation fails in up to 50%. We hypothesize that impairment of forearm venous distensibility, ie, the ability of veins to adjust to increased pressure, is related to AVF failure. Forearm venous distensibility was measured by using strain-gauge plethysmography in 27 patients with end-stage renal failure awaiting vascular access surgery; either AVF or graft (AVG) formation. Ultrasound duplex scanning of the upper-extremity circulation was performed 4 weeks before surgery. Failure to mature is defined as inability to use the AVF for hemodialysis within 8 weeks after surgery. Venous distensibility in patients receiving an AVG (n = 10) was 0.44 +/- 0.05 mL/mm Hg, and in patients receiving an AVF (n =17), 0.56 +/- 0.04 mL/mm Hg (P = 0.2). Venous distensibility was 0.46 +/- 0.03 mL/mm Hg in patients with an unsuccessful AVF (n = 9) and 0.66 +/- 0.05 mL/mm Hg in patients with a successful AVF (n = 8; P = 0.003). All 7 patients with venous distensibility of 0.50 mL/mm Hg or less had a nonfunctional AVF (100%), whereas only 2 of 10 patients with venous distensibility greater than 0.50 mL/mm Hg had a nonfunctional AVF (20%; P = 0.002). No differences were found in arterial and venous luminal diameters between functional and nonfunctional AVFs. These preliminary results suggest that forearm venous distensibility is a predictor of AVF success, whereas luminal diameters are not. Measurement of venous distensibility may be helpful in choosing the most suitable access type for each individual patient, possibly improving access patency.