Guideline recommendations on minimal blood vessel diameters and arteriovenous fistula outcomes.

OBJECTIVE: Clinical guidelines provide recommendations on the minimal blood vessel diameters required for arteriovenous fistula creation but the evidence for these recommendations is limited. We compared vascular access outcomes of fistulas created in agreement with the ESVS Clinical Practice Guidelines (i.e. arteries and veins >2 mm for forearm fistulas and >3 mm for upper arm fistulas) with fistulas created outside these recommendations. METHODS: The multicenter Shunt Simulation Study cohort contains 211 hemodialysis patients who received a first radiocephalic, brachiocephalic, or brachiobasilic fistula before publication of the ESVS Clinical Practice Guidelines. All patients had preoperative duplex ultrasound measurements according to a standardized protocol. Outcomes included duplex ultrasound findings at 6 weeks after surgery, vascular access function, and intervention rates until 1 year after surgery. RESULTS: In 55% of patients, fistulas were created in agreement with the ESVS Clinical Practice Guidelines recommendations on minimal blood vessel diameters. Concordance with the guideline recommendations was more frequent for forearm fistulas than for upper arm fistulas (65% vs 46%, p = 0.01). In the entire cohort, agreement with the guideline recommendations was not associated with an increased proportion of functional vascular accesses (70% vs 66% for fistulas created within and outside guideline recommendations, respectively; p = 0.61) or with decreased access-related intervention rates (1.45 vs 1.68 per patient-year, p = 0.20). In forearm fistulas, however, only 52% of arteriovenous fistulas created outside these recommendations developed into a timely functional vascular access. CONCLUSIONS: Whereas upper arm arteriovenous fistulas with preoperative blood vessel diameters <3 mm had similar vascular access function as fistulas created with larger blood vessels, forearm arteriovenous fistulas with preoperative blood vessel diameters <2 mm had poor clinical outcomes. These results support that clinical decision-making should be guided by an individual approach.

Editor's Choice - Interventions to Achieve Functionality in Newly Created Arteriovenous Fistulas in the Shunt Simulation Study Cohort.

OBJECTIVE: Although observational cohort studies report that interventions to achieve functionality are clinically successful in 85% of patients, the proportion of newly created autologous arteriovenous fistulas that result in functional vascular access typically is only 70 - 80%. To address this discrepancy, the selection and outcomes of interventions to achieve functionality in a multicentre prospective cohort study were analysed. METHODS: The Shunt Simulation Study enrolled 222 patients who needed a first arteriovenous fistula in nine dialysis units in The Netherlands from 2015 to 2018 and followed these patients until one year after access creation. In this observational study, the technical and clinical success rates of interventions to achieve functionality based on lesion and intervention characteristics were analysed and the clinical outcomes of arteriovenous fistulas with assisted and unassisted functionality were compared. RESULTS: For patients who were on dialysis treatment at the end of the study, unassisted fistula functionality was 54% and overall fistula functionality was 78%. Thirty-four per cent of arteriovenous fistulas required an intervention to achieve functionality, 68% of which eventually became functional. Seventy-five per cent of these interventions were percutaneous balloon angioplasties of vascular access stenoses. Patients with clinically successful interventions to achieve functionality had larger pre-operative vein diameters (2.8 ± 1.0 mm vs. 2.3 ± 0.6 mm, p = .036) and less often presented with thrombosed fistulas than patients with unsuccessful interventions (7% vs. 43%, p = .006). Arteriovenous fistulas with assisted functionality had similar secondary patency as fistulas with unassisted functionality (100% and 98% at six months, p = .44), although they required more interventions to maintain function (2.6 vs. 1.7 per year; rate ratio 1.52, 95% CI 1.04 - 2.18, p = .032). CONCLUSION: Interventions to achieve functionality were needed in about a third of newly created arteriovenous fistulas. Most thrombosed fistulas were abandoned, and when selected for thrombectomy rarely reached clinical success. On the other hand, interventions to achieve functionality of patent fistulas had high clinical success rates and therefore can be done repeatedly until the fistula has become functional.

A multicenter, randomized, dose-finding study of mechanochemical ablation using ClariVein and liquid polidocanol for great saphenous vein incompetence.

BACKGROUND: The purpose of the present study was to identify the ideal polidocanol (POL) concentration for mechanochemical ablation (MOCA) of the great saphenous vein (GSV) using the ClariVein system (Merit Medical, South Jordan, Utah). METHODS: We performed a multicenter, randomized, controlled, single-blind trial with a follow-up period of 6 months. Patients with symptomatic primary truncal GSV incompetence were randomized to MOCA + 2% POL liquid (2% group) or MOCA + 3% POL liquid (3% group). The primary outcome was technical success (TS), defined as an open part of the treated vein segment of ≤10 cm in length. The secondary outcomes were alternative TS, defined as ≥85% occlusion of the treated vein segment, postoperative pain, venous clinical severity scores, Aberdeen varicose vein questionnaire scores, and short-form 36-item health survey questionnaire scores, and complications. RESULTS: From 2012 to 2018, 364 patients (375 limbs) were included, of which, 189 limbs were randomly allocated to the 2% group and 186 to the 3% group. The TS rate at 6 months was 69.8% in the 2% group vs 78.0% in the 3% group (P = .027). A higher overall TS rate was seen in GSVs of ≤5.9 mm compared with GSVs >5.9 mm (84.3% vs 59.5%, respectively; P < .001). The alternative TS rate at 6 months was 61.4% in the 2% group and 67.7% in the 3% group (P = .028). The venous clinical severity scores, Aberdeen varicose vein questionnaire scores, and most short-form 36-item health survey questionnaire domains had improved in both groups (P < .002). Postprocedural pain was low. Two pulmonary embolisms and two deep vein thromboses were seen. Superficial venous thrombosis had occurred more often in the 3% group (18 vs 8 in the 2% group; P = .033). CONCLUSIONS: The results from the present study showed a higher success rate for MOCA with 3% POL liquid than for MOCA with 2% POL liquid at 6 months of follow-up. However, the difference in quality of life was not significant. Long-term follow-up studies are required to investigate whether these results will be sustained in the future.

CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis on Preventing Post-Thrombotic Syndrome) Trial: Long-Term Follow-Up Results.

Background The CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis Versus Anticoagulation for the Prevention of Post-Thrombotic Syndrome) trial did not show a reduction of post-thrombotic syndrome (PTS) after additional ultrasound-accelerated catheter-directed thrombolysis in patients with acute iliofemoral deep vein thrombosis at 1-year follow-up. This prespecified analysis of the CAVA trial aimed to determine the impact of additional thrombolysis on outcomes of PTS at long-term follow-up. Methods and Results Patients aged 18 to 85 years with a first-time acute iliofemoral deep vein thrombosis were included and randomly assigned (1:1) to either standard treatment plus ultrasound-accelerated catheter-directed thrombolysis or standard treatment alone. The primary outcome was the proportion of PTS (Villalta score ≥5 on 2 occasions ≥3 months apart or venous ulceration) at the final follow-up visit. Additionally, PTS according to the International Society on Thrombosis and Haemostasis (ISTH) consensus definition was assessed to allow external comparability. Major bleedings were the main safety outcome. At a median follow-up of 39.0 months (interquartile range, 23.3-63.8), 120 patients (79.8%) participated in the final follow-up visit: 62 from the intervention group and 58 from the standard treatment group. PTS developed in 19 (30.6%) versus 26 (44.8%) patients, respectively (odds ratio [OR], 0.54; 95% CI, 0.26 to 1.15 [P=0.11]), with an absolute difference between groups of -14.2% (95% CI, -32.0% to 4.8%). Using the ISTH consensus definition, a significant reduction in PTS was observed (29 [46.8%] versus 40 [69.0%]) (OR, 0.40; 95% CI, 0.19-0.84 [P=0.01]) with an absolute difference between groups of -22.2% (95% CI, -39.8% to -2.8%). No new major bleedings occurred following the 12-month follow-up. Conclusions The impact of additional ultrasound-accelerated catheter-directed thrombolysis on the prevention of PTS was found to increase with time. Although this study was limited by its sample size, the overall findings indicate a reduction of mild PTS without impact on quality of life. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00970619.

Open Repair of Two Ipsilateral Extracranial Internal Carotid Artery Aneurysms.

INTRODUCTION: A patient with two ipsilateral extracranial internal carotid artery (ICA) aneurysms treated by open repair is reported, with an emphasis on pre-operative planning and decision making, and a review of literature. REPORT: A 44 year old man was diagnosed with a right thyroid lobe nodule and two asymptomatic ipsilateral aneurysms of the right ICA. Diagnostic workup using three dimensional reconstruction and centre lumen line measurements on computed tomography revealed two aneurysms of the right ICA, both > 20 mm. Surgery was planned with intra-operative mandibular subluxation to maximise distal exposure. Neuromonitoring consisted of transcranial Doppler ultrasound and electroencephalography. After mandibular subluxation and complete dissection of the aneurysms and digastric muscle division, adequate exposure of the distal ICA was obtained, followed by resection of both aneurysms, and reconstruction with a reversed greater saphenous vein graft. No complications occurred and one year follow up showed a patent graft without signs of stenosis or anastomotic aneurysm. DISCUSSION: Open repair of two ipsilateral extracranial ICA aneurysms can be performed safely after careful pre-operative planning using visualisation of the vascular anatomy and distance measurements, and maximising exposure with digastric muscle division, styloidectomy, if necessary, and mandibular subluxation.

Association of Successful Ultrasound-Accelerated Catheter-Directed Thrombolysis with Postthrombotic Syndrome: A Post Hoc Analysis of the CAVA Trial.

BACKGROUND: The CAVA trial did not show the anticipated risk reduction for postthrombotic syndrome (PTS) after thrombus removal via additional ultrasound-accelerated catheter-directed thrombolysis (UACDT) in patients with acute iliofemoral deep vein thrombosis (IFDVT). Difficulties in achieving an effective degree of recanalization through thrombolysis may have influenced outcomes. We therefore assessed whether successful UACDT (restored patency ≥ 90%) did reduce the development of PTS. METHODS: This CAVA trial post hoc analysis compared the proportion of PTS at 1-year follow-up between patients with successful UACDT and patients that received standard treatment only. In addition, clinical impact as well as determinants of successful thrombolysis were explored. RESULTS: UACDT was initiated in 77 (50.7%) patients and considered successful in 41 (53.2%, interrater agreement κ = 0.7, 95% confidence interval 0.47-0.83). PTS developed in 15/41 (36.6%) patients in the successful UACDT group versus 33/75 (44.0%) controls (p = 0.44). In this comparison, successful UACDT was associated with lower Venous Clinical Severity Score (3.50 ± 2.57 vs. 4.82 ± 2.74, p = 0.02) and higher EuroQOL-5D (EQ-5D) scores (40.2 ± 36.4 vs. 23.4 ± 34.4, p = 0.01). Compared with unsuccessful UACDT, successful UACDT was associated with a shorter symptom duration at inclusion (p = 0.05), and higher rates of performed adjunctive procedures (p < 0.001) and stent placement (p < 0.001). CONCLUSION: Successful UACDT was not associated with a reduced proportion of PTS 1 year after acute IFDVT compared with patients receiving standard treatment alone. There was, however, a significant reduction in symptom severity and improvement of generic quality of life according to the EQ-5D. Better patient selection and optimization of treatment protocols are needed to assess the full potential of UACDT for the prevention of PTS. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number, NCT00970619.

Pre-operative Patient Specific Flow Predictions to Improve Haemodialysis Arteriovenous Fistula Maturation (Shunt Simulation Study): A Randomised Controlled Trial.

OBJECTIVE: An arteriovenous fistula (AVF) needs to mature before it becomes suitable to cannulate for haemodialysis treatment. Maturation importantly depends on the post-operative flow increase. Unfortunately, 20-40% of AVFs fail to mature (FTM). A patient specific computational model that predicts immediate post-operative flow was developed, and it was hypothesised that providing information from this model for planning of fistula creation might reduce FTM rates. METHODS: A multicentre, randomised controlled trial in nine Dutch hospitals was conducted in which patients with renal failure who were referred for AVF creation, were recruited. Patients were randomly assigned (1:1) to the control or computer simulation group. Both groups underwent a work up, with physical and duplex ultrasonography (DUS) examination. In the simulation group the data from the DUS examination were used for model simulations, and based on the immediate post-operative flow prediction, the ideal AVF configuration was recommended. The primary endpoint was AVF maturation defined as an AVF flow ≥500 mL/min and a vein inner diameter of ≥4 mm six weeks post-operatively. The secondary endpoint was model performance (i.e. comparisons between measured and predicted flows, and (multivariable) regression analysis for maturation probability with accompanying area under the receiver operator characteristic curve [AUC]). RESULTS: A total of 236 patients were randomly assigned (116 in the control and 120 in the simulation group), of whom 205 (100 and 105 respectively) were analysed for the primary endpoint. There was no difference in FTM rates between the groups (29% and 32% respectively). Immediate post-operative flow prediction had an OR of 1.15 (1.06-1.26; p < .001) per 100 mL/min for maturation, and the accompanying AUC was 0.67 (0.59-0.75). CONCLUSION: Providing pre-operative patient specific flow simulations during surgical planning does not result in improved maturation rates. Further study is needed to improve the predictive power of these simulations in order to render the computational model an adjunct to surgical planning.

Ultrasound-accelerated catheter-directed thrombolysis versus anticoagulation for the prevention of post-thrombotic syndrome (CAVA): a single-blind, multicentre, randomised trial.

BACKGROUND: Early thrombus removal might prevent post-thrombotic syndrome by preserving venous function and restoring flow. Previous trials comparing additional catheter-directed thrombolysis to standard treatment showed conflicting outcomes. We aimed to assess the benefit of additional ultrasound-accelerated catheter-directed thrombolysis for the prevention of post-thrombotic syndrome compared with standard therapy in patients with iliofemoral deep-vein thrombosis. METHODS: We did a multicentre, randomised, single-blind, allocation-concealed, parallel group, superiority trial in 15 hospitals in the Netherlands. Patients aged 18-85 years with a first-time acute iliofemoral deep-vein thrombosis and symptoms for no more than 14 days were randomly assigned (1:1) to either standard treatment with additional ultrasound-accelerated catheter-directed thrombolysis or standard treatment alone. Randomisation was done with a web-based automatic programme and a random varying block size (2-12), stratified by age and centre. Standard treatment included anticoagulant therapy, compression therapy (knee-high elastic compression stockings; 30-40 mmHg), and early ambulation. Additional ultrasound-accelerated catheter-directed thrombolysis was done with urokinase with a starting bolus of 250 000 international units (IU) in 10 mL NaCl followed by a continuous dose of 100 000 IU/h for a maximum of 96 h through the Ekos Endowave-system. Adjunctive percutaneous transluminal angioplasty, thrombosuction, or stenting was performed at the discretion of the physician who performed the intervention. The primary outcome was the proportion of patients with post-thrombotic syndrome at 12 months diagnosed according to the original Villalta criteria-a Villalta-score of at least 5 on two consecutive occasions at least 3 months apart or the occurrence of venous ulceration-and was assessed in a modified intention-to-treat population of all randomly assigned patients who passed screening and started treatment. The safety analysis was assessed in the same modified intention-to-treat population. This study is complete and is registered at ClinicalTrials.gov, NCT00970619. FINDINGS: Between May 28, 2010, and Sept 18, 2017, 184 patients were randomly assigned to either additional ultrasound-accelerated catheter-directed thrombolysis (n=91) or standard treatment alone (n=93). Exclusion because of screening failure or early withdrawal of informed consent resulted in 77 patients in the intervention group and 75 in the standard treatment group starting allocated treatment. Median follow-up was 12·0 months (IQR 6·0-12·0). 12-month post-thrombotic syndrome occurred in 22 (29%) patients allocated to additional treatment versus 26 (35%) patients receiving standard treatment alone (odds ratio 0·75 [95% CI 0·38 to 1·50]; p=0·42). Major bleeding occurred in four (5%) patients in the intervention group, with associated neuropraxia or the peroneal nerve in one patient, and no events in the standard treatment group. No serious adverse events occurred. None of the four deaths (one [1%] in the intervention group vs three [4%] in the standard treatment group) were treatment related. INTERPRETATION: This study showed that additional ultrasound-accelerated catheter-directed thrombolysis does not change the risk of post-thrombotic syndrome 1 year after acute iliofemoral deep-vein thrombosis compared with standard therapy alone. Although this trial is inconclusive, the outcome suggests the possibility of a moderate beneficial effect with additional ultrasound-accelerated catheter-directed thrombolysis. Further research is therefore warranted to better understand this outcome in the context of previous trials, preferably by combining the available evidence in an individual patient data meta-analysis. FUNDING: The Netherlands Organisation for Health Research and Development (ZonMw), Maastricht University Medical Centre, BTG-Interventional Medicine.

The role of infragenicular spliced vein bypass surgery in patients with chronic limb-threatening ischemia: single center long-term results.

BACKGROUND: In patients requiring infrageniculate surgical revascularization a single-segment great saphenous vein (SS-GSV) is the optimal conduit. In the absence of a SS-GSV, the small saphenous vein and arm veins can also be used to obtain an all-autologous bypass. The aim of this study was to compare the long-term results of infrageniculate SS-GSV bypasses and spliced vein bypasses in patients with chronic limb-threatening ischemia (CLTI). METHODS: A total of 308 consecutive CLTI patients who underwent a primary infragenicular, autologous bypass between January 2000 and December 2016 were included. The definition of a spliced vein bypass was a graft consisting of at least two venous segments. RESULTS: A SS-GSV graft was used in 235 patients, and a spliced vein graft was used in 73 patients. Significantly more infrapopliteal bypasses were performed in the spliced vein group (P=0.024), and in this group the mean operation time was almost 60 minutes longer (P<0.001). The overall morbidity rate was 44%. The overall 30-day mortality was 3.2%, and overall in-hospital mortality was 4.9%. No significant differences were observed between the groups in mortality, overall morbidity or any specific complication. Comparing the SS-GSV group with the spliced vein group, no significant differences were observed between overall survival (53.2% vs. 45.7%), primary patency (55.5% vs. 53.2%), assisted primary patency (78.5% vs. 76.5%), secondary patency (87.9% vs. 90.6%) and limb salvage (83.3% vs. 82.0%). CONCLUSIONS: The use of infrageniculate spliced vein bypasses for the treatment of CLTI patients results in similar results compared with infrageniculate SS-GSV bypass grafts. A strict surveillance protocol in the first 2 years and a liberal reintervention strategy may result in excellent long-term patency rates.

Age-Related Effects of Bariatric Surgery on Early Atherosclerosis and Cardiovascular Risk Reduction.

BACKGROUND: Carotid intima-media thickness (CIMT) is increasingly used as a prognostic indicator for early atherosclerosis and the development of cardiovascular disease. The objective of this study is to assess the exact effects of bariatric surgery on CIMT reduction in different age groups. METHODS: CIMT was measured just proximal to the bifurcation of the carotid artery in 166 patients with mean body mass index of 43.4 kg/m2 before and at 6 and 12 months after bariatric surgery. Preoperative CIMT and Framingham Risk Score (FRS) were compared to measurements at 6 and 12 months, postoperatively. Impact of age on CIMT change and cardiovascular risk reduction was analyzed. RESULTS: Median follow-up was 12 months; 12% were lost to follow-up. Mean CIMT values at 12 months after bariatric surgery were significantly lower compared to baseline (0.619 vs. 0.587 mm, p = 0.005 in women and 0.675 vs. 0.622 mm, p = 0.037 in men, respectively), and these effects were statistically significant in all age groups. The mean reduction of CIMT for patients < 50 years at 12 months was 0.043 mm (- 7.0%), while CIMT was reduced with 0.013 mm for patients ≥ 50 years (- 1.9%, p = 0.022). At 12 months after bariatric surgery, FRS had decreased with 52% in patients < 50 years as compared with 35% in patients ≥ 50 years (p = 0.025). CONCLUSIONS: Bariatric surgery resulted in a significant CIMT decrease in patients with morbid obesity in all evaluated age categories. These beneficial effects of bariatric surgery were more pronounced in younger patients, while cardiovascular risk reduction by bariatric surgery appeared inferior in patients of 50 years and older.

Correction to: Age-Related Effects of Bariatric Surgery on Early Atherosclerosis and Cardiovascular Risk Reduction.

Frederik H. W. Jonker and Vera A. A. van Houten contributed equally to this work.

Drug-eluting balloons and uncoated balloons perform equally to rescue infrainguinal autologous bypasses at risk.

OBJECTIVE: Endovascular treatment of a significant stenosis in an infrainguinal autologous bypass prevents bypass occlusion and improves bypass patency. Drug-eluting balloons (DEBs) have been proven to possess antirestenotic features in the treatment of femoropopliteal stenoses and occlusions. This study evaluated the effects of DEB angioplasty vs uncoated balloon (UCB) angioplasty to rescue infrainguinal autologous bypass grafts at risk (BAR). METHODS: The study included all consecutive patients treated endovascularly for BAR from December 1, 2012, to July 31, 2015. As of April 1, 2014, the primary treatment of BAR was changed from UCBs to DEBs. Patients treated with DEBs were prospectively recorded in a database and retrospectively analyzed. Patients treated with UCBs were retrospectively collected from a historical cohort with a similar inclusion period length as the DEB cohort. The follow-up scheme did not differ between the two groups. The primary end point was the combined end point of freedom from recurrent stenosis or bypass occlusion. Secondary end points were primary assisted patency, secondary patency, technical success, major amputation, and mortality. RESULTS: Twenty-one patients were treated in the DEB group and 18 were treated in the UCB group. The two groups were evenly distributed in demographics, bypass, treatment, and lesion characteristics. No statistically significant differences were found in the combined end point of freedom from recurrent stenosis and the occlusion rate after 1 year between the UCB group (77.8%) and the DEB group (80.0%; P = .76). After 1 year, the primary assisted patency rate was 88.2% in the UCB group vs 95.2% in the DEB group (P = .47), and the secondary patency rate was 94.1% in the UCB group vs 95.2% in the DEB group (P = .91). During follow-up, restenosis developed in four patients (22.2%) in the UCB group and in four patients (19.0%) in the DEB group (P = .80). One bypass (5.6%) in the UCB group and one bypass (4.8%) in the DEB group occluded during follow-up (P = .884). CONCLUSIONS: DEBs and UCBs perform equally in the treatment of significant stenosis in infrainguinal autologous bypasses with regard to freedom from restenosis or bypass occlusion, primary assisted patency, and secondary patency at 1 year. We suggest using a less expensive UCB in the treatment of BAR.

Endovenous laser ablation versus conventional surgery in the treatment of small saphenous vein incompetence.

INTRODUCTION: In this multicenter, randomized controlled trial, endovenous laser ablation (EVLA) is compared with conventional surgery for the treatment of varicose veins based on incompetence of the small saphenous vein and the saphenopopliteal junction (SPJ). METHODS: In two Dutch hospitals, 189 patients were enrolled and randomized to receive EVLA (810-nm laser) or ligation of the SPJ. End points were success rate measured with duplex ultrasound (6 weeks post-treatment), perioperative pain, quality of life, duration of surgery, difficulty of surgery, complications, cosmetic results, and number of days to resume work and normal activities. Pain was measured on a visual analog scale (VAS). Quality of life was assessed using the Aberdeen Varicose Vein Questionnaire (AVVQ) and Euro Qol-5D. The follow-up duration in this article is 6 weeks. RESULTS: One hundred seventy-five patients have been treated and analyzed. One hundred eighteen patients (67%) underwent EVLA, and 57 patients (33%) underwent ligation of the SPJ. The patient characteristics were similar in both groups. In the surgery group, 21% residual incompetence of the SPJ was seen after 6 weeks, compared with 0.9% in the laser group. Both treatment modalities reduced pain after 6 weeks. One week post-treatment, patients in the EVLA group temporarily experienced more pain compared with the surgery group (31 vs 18 on a VAS from 0 to 100). There were no significant differences between the two groups with respect to quality of life. Both treatments did show improvement in quality of life. Also with regard to the cosmetics, there were no differences, aside from the fact that patients rated their scar as more beautiful after EVLA. After EVLA, patients could return to work more quickly. The operation time was longer in the surgery group. After 2 weeks, there were significantly more neurological complications in the surgery group: 18 (31%) vs 16 (17%) patients in the EVLA group. Ten percent of patients in the surgery group developed a surgical site infection vs 0% in the EVLA group. CONCLUSIONS: EVLA provides an excellent alternative to conventional surgery in the treatment of symptomatic varicose veins due to an incompetent small saphenous vein with SPJ. EVLA has a superior immediate success rate, is easier and faster, and has fewer complications.

Secondary interventions in patients with autologous arteriovenous fistulas strongly improve patency rates.

BACKGROUND: Nowadays, as a result of more liberal selection criteria, dialysis-dependent patients have become substantially older, more likely to be female and diabetic, and have more comorbidity. The 1-year primary patency rates of arteriovenous fistulas (AVFs) are poor. To improve these results, several secondary interventions can be performed. The aim of this study was to evaluate the results after secondary interventions in patients with an upper extremity AVF. METHODS: Between January 2000 and December 2008, all consecutive patients who underwent construction of an autologous upper extremity AVF were included. Patient characteristics were collected retrospectively from digital patient files and a prospectively recorded database on hemodialysis patients. RESULTS: Between January 2000 and December 2008, 736 hemodialysis access procedures were performed. A total of 347 autologous arteriovenous fistulas (AVFs) were created in 294 patients. The mean age was 62.1 ± 14.7 years, and the majority (66%) of the patients was male. Mean follow-up of all 347 fistulas was 21.9 ± 21.6 months. During follow-up, failure occurred in 209 (60%) of the AVFs. A total of 133 of these failures were followed by a secondary intervention, of which 78 (59%) were endovascular interventions. Twenty-nine patients developed a third failure, and 25 of these patients underwent another intervention, of which 22 were percutaneous transluminal angioplasty for stenosis. Fifteen patients developed a fourth failure, and all of them underwent an intervention. One patient had 11 interventions. The 1- and 2-year primary patency rates were 46% and 36.8%, respectively. The 1- and 2-year primary assisted patency rates were 74.6% and 71.2%, respectively. The 1- and 2-year secondary patency rates were 79.2% and 77.8%, respectively. CONCLUSION: The primary patency rate of AVFs is disappointing. However, due to mostly endovascular secondary interventions, 2-year primary assisted and secondary patency rates of more than 70% can be obtained.

A randomized multicenter study of the outcome of brachial-basilic arteriovenous fistula and prosthetic brachial-antecubital forearm loop as vascular access for hemodialysis.

BACKGROUND: Vascular access is a necessity for patients with end-stage renal disease who need chronic intermittent hemodialysis. According to Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines, radial-cephalic (RC) and brachial-cephalic (BC) arteriovenous fistulas (AVF) are the first and second choice for vascular access, respectively. If these options are not possible, an autogenous brachial-basilic fistula in the upper arm (BBAVF) or a prosthetic brachial-antecubital forearm loop (PTFE loop) may be considered. Until now, it was not clear which access type was preferable. We have performed a randomized study comparing BBAVF and prosthetic implantation in patients without the possibility for RCAVF or BCAVF. METHODS: Patients with failed primary/secondary access or inadequate arterial and/or venous vessels were randomized for either BBAVF or PTFE loop creation. The numbers of complications and interventions were recorded. Kaplan-Meier method was used to calculate primary, assisted-primary and secondary patency rates. The patency rates were compared with the log-rank test. Complication and intervention rates were compared with the Mann-Whitney test. RESULTS: A total of 105 patients were randomized for a BBAVF or PTFE loop (52 vs 53, respectively). Primary and assisted-primary 1-year patency rates were significantly higher in the BBAVF group: 46% +/- 7.4% vs 22% +/- 6.1% (P = .005) and 87% +/- 5.0% vs 71% +/- 6.7% (P = .045) for the BBAVF and PTFE group, respectively. Secondary patencies were comparable for both groups; 89% +/- 4.6% vs 85% +/- 5.2% for the BBAVF and PTFE group, respectively. The incidence rate of complications was 1.6 per patient-year in the BBAVF group vs 2.7 per patient-year in the PTFE group. Patients in the BBAVF group needed a total of 1.7 interventions per patient-year vs 2.7 per patient-year for the PTFE group. CONCLUSION: These data show a significantly better primary and assisted-primary patency in the BBAVF group compared with the PTFE group. Furthermore, in the BBAVF group, fewer interventions were needed. Therefore, we conclude that BBAVF is the preferred choice for vascular access if RCAVF or BCAVF creation is impossible, or when these types of access have already failed.

Forearm venous distensibility predicts successful arteriovenous fistula.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Ultrasound-guided percutaneous transabdominal treatment of a type 2 endoleak.

We describe a case of multiple endoleaks following endovascular repair of an abdominal aortic aneurysm, treated by various methods. A new transabdominal embolization approach using color-flow duplex guidance is presented.