Use of a Paclitaxel Drug-Eluting Stent for the Treatment of Hemodialysis Access Outflow Stenosis.

PURPOSE: To evaluate the outcomes and durability of drug-eluting stents (DESs) for the treatment of hemodialysis access outflow stenosis. MATERIAL AND METHODS: A single-center retrospective analysis was conducted of all patients with hemodialysis vascular access outflow stenosis treated with a paclitaxel-coated DES (Eluvia; Boston Scientific, Marlborough, Massachusetts) between January 2020 and July 2022. A total of 34 DESs were implanted to treat outflow stenosis in 32 patients. Primary target lesion patency after stent deployment was the main outcome. Comparison between the time interval free from target lesion reintervention (TLR) after previous plain balloon angioplasty (PBA) and that after stent deployment for the same target lesion was considered a secondary outcome. RESULTS: The primary patency at 6, 12, and 18 months was 63.1%, 47.6%, and 41.7%, respectively. The secondary patency rate was 100% at 18 months. The median time interval free from TLR increased from 4.1 to 11.9 months (P < .001). No adverse events were observed during the median follow-up period of 387 days. CONCLUSIONS: The patency rates after use of DES for hemodialysis access outflow stenosis were comparable with results for drug-coated balloons and stent grafts, addressing recoil and minimizing the risk of jailing by a covered stent.

Maintaining Vascular Access Response in a Severely COVID-19 Hit Country.

INTRODUCTION: The COVID-19 pandemic has caused an unprecedented disruption in healthcare systems worldwide, and Portugal was no exception. We analyze the impact of the COVID-19 pandemic in activity of our Vascular Access Center (Grupo Estudos Vasculares - GEV). MATERIAL AND METHODS: This is a retrospective study, during March 2019 and February 2021. An analysis of surgical and appointments records in 2,495 patients from 25 hemodialysis centers followed by GEV was performed. Patients were divided into two periods: non-pandemic (NPP) (March 2019 to February 2020) and pandemic periods (PP) (March 2020 to February 2021). The number of surgeries and appointments were analyzed per month and per week. The number of thrombosis were analyzed in both periods. Normality was tested by the Shapiro-Wilk test and by the Lilliefors (Kolmogorov-Smirnov) test. Comparisons were made by the t-test (paired samples) when normality was not rejected and by the Wilcoxon test otherwise. All the variables (normal or otherwise) were described by the usual descriptive measures such as the mean, median and quartiles. No categorical data were collected. To avoid COVID-19 infection a set of measures were created: Sars-cov-2 PCR test for every patient, individual protection equipment for staff, rotating teams and schedules, and only one patient allowed in the circuit to the intervention room. A descriptive statistical analysis was performed with SPSS version28. The statistical significance was confirmed for p-value < 0.05. RESULTS: A total of 1756 surgeries and 800 appointments were made in both PP and NPP. Comparing the periods, we performed 914 (52%) interventions in the NPP and 842 (48%) in PP, 423 (53%) consultations in NPP and 377 (47%) at PP. Comparing the NPP and PP by months we observed more appointments in the NPP (p=0.004). However, the difference in the number of surgeries did not reach statistical significance (p=0.533). There were more thrombosis during the summer and fall in the NPP and PP. A total of 138 in NPP and 131 in PP thrombosis were observed in the 2 years period. There was no record of COVID-19 infections between all GEV staff (n=25). CONCLUSION: Due to timed and tight set of measures taken in the pandemic lockdown by GEV, a similar clinical and surgical activity regarding hemodialysis patients was obtained in both periods (PP and NPP). The hypothesis that the PP could diminish vascular access assessment/intervention or more thrombosis could occur was not verified at our institution. The set of measures established to deal with the COVID-19 pandemic was also effective to prevent infection in staff members.

Arterial percutaneous angioplasty in hemodialysis access: Endovascular treatment of hand ischemia.

BACKGROUND: Hemodialysis access-induced distal ischemia consists of symptomatic extremity malperfusion after vascular access creation. It is usually caused by discordant vascular resistance, with arteriovenous shunting of a high blood volume from arterial into venous system and subsequent hand hypoperfusion. Less often, hemodialysis access-induced distal ischemia is caused by arterial stenosis. In these cases, access frequently has normal/low flow, radial pulse is usually absent and not recoverable with vascular access digital compression, diabetes is often present, and percutaneous transluminal angioplasty can be critical for access and limb salvage. METHODS: Retrospective study conducted between June 2011 and February 2018 of patients with vascular access submitted to arterial percutaneous transluminal angioplasty for limb-threatening ischemia. RESULTS: Twenty-nine patients were referred for arterial angiography after hemodialysis access-induced distal ischemia diagnosis and physical examination or ultrasound findings suggestive of arterial disease. In 11 patients, percutaneous transluminal angioplasty was not technically feasible. Among 18 treated patients, 83.3% had diabetes and 60% had skin ulcerations. Target arteries were radial (11), brachial (7), axillar (2), ulnar (2), and subclavian (1). Clinical success, defined as arteriovenous maintenance and wound healing/pain resolution, was observed in 12 patients (66.7%). Concomitant procedures included adjuvant banding (n = 2) and finger amputation (n = 1), and one reintervention was performed. No intra- or postoperative complications were reported. CONCLUSION: Hemodialysis access-induced distal ischemia is a serious complication of hemodialysis vascular access, with multifactorial etiology. Correct and timely diagnosis is crucial for maintaining access and limb salvage. Percutaneous transluminal angioplasty is a minimally invasive procedure that may be effective and long-lasting in carefully selected patients with ischemic complaints.

The Role of Doppler Ultrassonography in Significant and Borderline Stenosis Definition.

BACKGROUND: The definition of significant stenosis (SS) remains controversial. METHODS: We retrospectively reviewed 1,040 consultations. SS was defined in the presence of clinical and echo-Doppler (DDU) criteria: Qa <500 mL/min or Qa decrease >25%; RI >0.7 in the feeding artery or absolute minimal luminal stenosis diameter <2.0 mm. Stenosis without any additional criteria were considered borderline stenosis (BS). RESULTS: Two hundred twenty-one arteriovenous fistulas (AVFs) were included: 58.8% had SS, 18.6% had BS, and 22.6% had no dysfunctional access (ND). SS had a significantly higher thrombotic events than BS and ND (13.1 vs. 4.4%, p = 0.018). The annual thrombosis rate was 0.007, 0.037, and 0.004 in the ND, SS, and BS, respectively. AVF cumulative survival at 5 years was significantly lower in SS (89.5%) compared to BS (100%) and ND (97.4%; p = 0.03). BS had an HR for AVF failure of 1.1, p = 0.955, while the SS presented an HR of 5.9, p = 0.09. CONCLUSION: AVF clinical monitoring with additional DDU criteria appear to be appropriate for therapeutic referral.

Preoperative vessel mapping in chronic kidney disease patients - a center experience.

PURPOSE: Hemodialysis (HD) is the main treatment modality in stage 5 chronic kidney disease, and vascular access planning is a crucial step in the path to dialysis treatment. Beyond detailed patient history and physical examination, duplex ultrasound (DU) evaluation is essential in preoperative vascular mapping. METHODS: A retrospective descriptive nonrandomized study was performed and included 108 end-stage kidney disease patients referred from eight HD centers to be assessed for creation of an arteriovenous (AV) access (AV fistula or AV graft). We assessed primary failure, primary unassisted patency (PP) and primary assisted patency (PAP) rates and cumulative survival of AV accesses at 6 and 12 months. RESULTS: We created 86 AV accesses of which 79 (91.9%) were AV fistulas (AVFs) (29 distal AVFs, 49 proximal AVFs and 1 femorofemoral AVF) and 7 (8.1%) arteriovenous grafts (AVGs). Fifteen percent (15%) (n = 12) of primary failure occurred in the AVF group. Any case of primary failure was observed between AVGs.In the AVF group, PP at 6 months was 63.8 % and at 12 months was 48.3%, PAP was 80.7% at 6 and 12 months. PP excluding primary failures was 73.0% and 55.3% at 6 and 12 months, respectively. The cumulative survival at 6 and 12 months was 80.7%.In the AVG group, PP at 6 months and 12 months was 66.7%, PAP and cumulative survival at 6 and 12 months were of 100%. CONCLUSIONS: This study demonstrates that preoperative vascular mapping with a patient-centered approach may be critical to achieve good outcomes allowing the increase in AVF access.