Trans-radial percutaneous intervention for thrombosed hemodialysis access: A single-center experience

Background: Traditionally, percutaneous transluminal angioplasty (PTA) is a first-line approach for stenosed dialysis accesses and has been performed through the non-thrombosed vein segment. For thrombosed accesses, thrombectomy (whether open or percutaneous) is a standard approach. The primary objective of our study is to determine the clinical and technical outcomes of the trans-radial approach of PTA among thrombosed dialysis accesses, in terms of safety and feasibility, technical and clinical aspects and factors influencing them, as well as assisted primary patency, secondary patency at 6 and 12 months. Methods: This is a single-center retrospective study that included 150 patients over 3 years. About 123 patients underwent successful percutaneous balloon angioplasty through the radial access. Results: We report an overall technical and clinical success rate of 82%, assisted primary patency rate of about 90.25% at 3 months, 82.93% at 6 months, 73.18% at 1 year, and secondary patency rate of 94% at 1 year. Twenty-seven patients were referred for surgical revisions/creation of a new fistula for reasons like inability to pass wire (6 patients), unfavorable anatomical variations like aneurysms at the proximal segments (5 patients), inability to cross the fistula (5 patients), and persistent fistula dysfunction with no flow after initial balloon dilatation (11 patients). Three patients had hematoma at the radial access site (2.5%) while two patients had the AV fistula segment rupture and were successfully treated conservatively. Conclusion: We conclude that PTA through the trans-radial approach to completely thrombosed hemodialysis accesses is a good alternative to transvenous access and has a very good assisted primary patency and secondary patency at 1 year without major complications.

To Close, Observe, or Reconstruct: The Third Way of Managing Dialysis Fistula Aneurysms in Kidney Transplant Recipients

Background: The management of patent dialysis fistulas in patients after kidney transplantation (KTx) is controversial—the options that are usually considered are the fistula’s closure or observation. Many complications of dialysis fistulas occur in patients after KTx, and immunosuppression increases the risk of fistula aneurysms and hyperkinetic flow. This study aimed to evaluate the results of dialysis fistula aneurysm treatment in patients after KTx and to compare them to procedures performed in an end-stage renal disease (ESRD) dialyzed population. Methods: We enrolled 83 renal transplant recipients and 123 ESRD patients with dialysis fistula aneurysms qualified for surgical revision to this single-center, prospective study. The results of the surgical treatment of dialysis fistula aneurysms were analyzed, and the primary, assisted primary and secondary patency rate, percentage and type of complications were also assessed. Results: For the treatment of dialysis fistula aneurysms in transplant patients, we performed dialysis fistula excisions with fistula closure in 50 patients (60.2%), excision with primary fistula reconstruction (n = 10, 12.0%) or excision with PTFE bypasses (n = 23, 27.7%). Postoperative complications occurred in 11 patients (13.3%) during a follow-up (median follow-up, 36 months), mostly in distant periods (median time after correction procedure, 11.7 months). The most common complication was outflow stenosis, followed by hematoma, dialysis fistula thrombosis and the formation of a new aneurysm and postoperative bleeding, infection and lymphocele. The 12-month primary, primary assisted and secondary patency rates of fistulas corrected by aneurysm excision and primary reconstruction in the KTx group were all 100%; in the control ESRD group, the 12-month primary rate was 70%, and the primary assisted and secondary patency rates were 100%. The 12-month primary, primarily assisted and secondary patency rates after dialysis fistula aneurysm excision combined with PTFE bypass were better in the KTx group than in the control ESRD group (85% vs. 71.8%, 90% vs. 84.5% and 95% vs. 91.7%, respectively). Kaplan–Meier analysis showed a significant difference in primary patency (p = 0.018) and assisted primary (p = 0.018) rates and a strong tendency in secondary patency rates (p = 0.053) between the KTx and ESRD groups after dialysis fistula excisions combined with PTFE bypass. No statistically significant differences in patency rates between fistulas treated by primary reconstruction and reconstructed with PTFE bypass were observed in KTx patients. Conclusions: Reconstructions of dialysis fistula aneurysms give good long-term results, with a low risk of complications. The reconstruction of dialysis fistulas can be an effective treatment method. Thus, this is an attractive option in addition to fistula ligation or observation in patients after KTx. Reconstructions of dialysis fistula aneurysms enable the preservation of the dialysis fistula while reducing various complications.

Long-term outcomes of thigh arteriovenous graft stenting

Background: Stents have been increasingly used for treating venous anastomosis stenosis seen in arteriovenous grafts (AVGs). A major reason for this trend is that stents can potentially confer a better patency rate compared to angioplasty. However, limited data are available about the outcomes of stents that are used to treat thigh AVG dysfunction. This study sought to assess the primary and secondary patency rates of stents used to treat thigh AVGs dysfunction at one year. Methods: This is a retrospective study of dialysis patients who received therapy via thigh grafts (N=50) and underwent stent placement between January 2005 and June 2017 at our center. Data on demographics and baseline characteristics of the study population were collected. The primary and secondary patency rates were defined as the time between stent deployment and the first intervention and second intervention, respectively. Patency and re-intervention rates were estimated using Kaplan-Meier survival analysis. Results: This study included 50 patients with thigh AVGs; mean age was 50.5± 15.5 years; 52% were female; 80% were black; and 90% had hypertension. The main indication for stenting was thrombosis due to venous anastomosis stenosis (74%). The number (mean ± SD) of stents deployed was 1.24 ± 0.8. The primary patency rate at three months and one year was 58.7% and 30.7%. In comparison, the secondary patency rate at three months and one year was 68.2% and 40.7% (p=0.04) Conclusions: Thigh AVG stenting can be successfully used to improve the overall patency rates of failing AVGs.

Long-term outcomes of anterior chest wall arteriovenous graft with polyurethane

Background: Anterior chest wall arteriovenous graft (ACWAVG) is one option for haemodialysis patients when vessels of the upper extremities become exhausted. We report here the long-term outcomes of ACWAVG with polyurethane. Methods: From April 2005 to October 2015, nine ACWAVGs with polyurethane grafts were created. We observed patients until April 2019 and evaluated graft patency, interval from operation to first cannulation, and numbers of interventions and complications. Results: Primary patency rate and secondary patency rate of 6, 12 and 24 months were 55.3%, 33.3%, 33.3% and 77.8%, 55.6%, 55.6% respectively. Mean interval from operation to first cannulation was 3 days. Infection rate and kinking formation rate were slightly higher than previous reports of ACWAVGs with expanded polytetrafluoroethylene (ePTFE). However, one patient was able to keep using a single graft for 166 months with multiple interventions. Conclusions: Slight disadvantage are seen with patency rate and complication rate in polyurethane ACWAVG compare to ePTFE. However, when early cannulation is required, polyurethane is worth to consider for creating ACWAVG.

Factors associated with infrainguinal bypass graft patency at 1-year; a retrospective analysis of a single centre experience

Introduction: The aim of this study was to identify factors associated with primary graft patency 1 year following open lower limb revascularisation (LLR) at a tertiary referral vascular service. Methods: A retrospective analysis of patients undergoing infra-inguinal bypass surgery between January 2016 and May 2017 at a tertiary vascular centre (St Mary’s Hospital, London) was performed. Data regarding patient demographics, comorbidities, type of operation and post-operative anti-thrombotic strategy were collected. Quality of run-off score was assessed from pre-operative imaging. Results: Seventy-seven cases were included in the analysis. Overall, the primary patency rate at 1-year was 63.6% ( n = 49/77) and the secondary patency rate was 67.5% ( n = 52/77). Independent variables with statistically significant inferior patency rates at 1-year were (1) bypasses with below knee targets (p = 0.0096), (2) chronic limb threatening ischaemia indication (p = 0.038), (3) previous ipsilateral revascularisation (p < 0.001) and (4) absence of hypertension history (p = 0.041). There was also a trend towards significance for American Society of Anesthesiologists (ASA) grade (p = 0.06). Independent variables with log-rank test p values of <0.1 were included in a Cox proportional hazards model. The only variable with a statistically significant impact on primary patency rates was previous open or endovascular ipsilateral revascularisation (HR 2.44 (1.04–5.7), p = 0.04). Conclusion: At 1-year follow-up, previous ipsilateral revascularisation was the most significant factor in affecting patency rates. Patients in this subgroup should therefore be deemed high-risk, which should be reflected in the informed consent and peri-operative management.

A systematic review of the brachial vein arteriovenous fistulas as a viable option for haemodialysis access

Objectives: International guidelines recommend the use of autogenous vascular access. Where suitable superficial veins are unavailable deeper veins may be used as an option. In most cases, basilic veins are used when cephalic veins are unavailable; arteriovenous fistulas using the brachial vein from the deep venous network are rare. Therefore, the purpose of the present study was to conduct a systematic review of the available literature evaluating the use of the brachial vein in arteriovenous fistulas. Methods: Systematic literature search of electronic databases in accordance with PRISMA was conducted. The primary outcomes of this study were primary and secondary patency rates for brachial vein arteriovenous fistulas; the secondary outcomes were the rates of access thrombosis, steal syndrome, pseudo-aneurysm and infection. Results: The 1-year primary, assisted, and secondary patency was recorded at (24%–77%), (45%–85%) and (45%–96%), respectively. The 2-year primary, assisted and secondary patency rate was recorded at (12%–46%), (19%–75%) and (19%–92%), respectively. However, the consistency regarding the reports and definitions used were highly variable. The incidence rate of infection, thrombosis and steal syndrome was 5% (0%–12%), 15.9% (9.5%–35%) and 3% (2%–6%), respectively. Conclusion: Available studies support the use of brachial veins as a reliable access option in patients with non-accessible superficial veins where an autologous option is required.

Use of the Viabahn covered stent for the treatment of venous rupture during interventions of dysfunctional or thrombosed hemodialysis vascular access

Background: Angioplasty-related vessel rupture is a common complication of interventions. The effect of covered stents to treat venous rupture has been evaluated in smaller series, but should be further evaluated. Objective: To report the immediate outcomes and patency rates of a covered stent to rescue angioplasty-related venous rupture of hemodialysis vascular access. Methods: From January 2013 to December 2018, 113 procedures complicated with vessel ruptures were retrospectively analyzed from a prospectively collected database of 8146 hemodialysis access interventions. The strategies to salvage vessel ruptures were based on the discretion of the treating physicians. Follow-up outcomes were obtained via review of the angiographic images, procedural notes, and medical and dialysis records within 12 months after the index procedures. Results: A total of 52 vessel ruptures (21 fistulas, 31 grafts) salvaged by using Viabahn covered stents were enrolled. Vessel ruptures developed in 28 (53.8%) thrombectomy procedures. Device success was achieved in all procedures (100%) and clinical success was achieved in 50 (96.2%). The primary patency of the stent area was 66.0% at 6 months and 50.0% at 12 months. The primary patency of the entire access circuit was 27.4% at 6 months and 16.0% at 12 months. The most common cause of access circuit primary patency loss was thrombotic occlusion for graft accesses and restenosis at stent area for native accesses. Eleven vascular accesses were abandoned within 12 months after vessel ruptures, and the secondary patency rate of the entire access circuit was 78.0% at 12 months. Conclusions: Treatment of angioplasty-induced vessel rupture of hemodialysis vascular accesses by using Viabahn covered stents has good immediate outcomes and patency results at the stent area. Nonetheless, the patency rate of entire access circuit was still below the threshold recommended by guidelines.

COVID-19 and Singapore: From Early Response to Circuit Breaker

Introduction: This paper presents our experience with deep venous stenting in a multi-ethnic Asian cohort of patients with symptomatic Non-Thrombotic Iliac Vein Lesions (NIVL) and Post-Thrombotic Syndrome (PTS). Materials and Methods: This was a multicentre retrospective cohort study of patients who had symptomatic deep venous disease. Stent patency rate was evaluated using Duplex ultrasonography immediately post-intervention and at 3, 6 and 12 months. Clinical outcomes were evaluated using the revised Venous Clinical Severity Score (rVCSS) and Visual Analogue Scale (VAS) pain score at baseline and 3 months post-procedure. Results: 87 patients (males = 47/87 (54.0%)); median age = 62 years (IQR 55 – 70)) and 115 limbs were analysed (left = 76/115 (66.1%)). Median follow-up time was 175 (IQR 57 – 257) days. 97/115 (84.3%) had NIVLs and 55/115 (47.8%) had May-Thurner-Syndrome. 43/115 (37.4%) had Clinical, Etiology, Anatomy and Pathophysiology (CEAP) 6 disease. Primary stent patency rates were 98.2% (112/114), 97.9% (93/95), 95.7% (89/93) and 92.8% (64/69) immediately postintervention, 3, 6 and 12 months, respectively. The 6-month secondary patency rate was 99.1% (114/115). Mean rVCSS and VAS improved from 11.52 (±3.54) to 5.77 (±2.36) (P < 0.01) and 6.62 (±1.93) to 2.92 (±1.50) (P < 0.01) respectively, at 3 months. 41/43 (95.3%) venous ulcers healed over a median time of 169 days (IQR 120 – 253). Conclusions: Short term primary patency rates following deep venous stenting are excellent, with few re-interventions. Patients presented with NIVLs rather than PTS. There was excellent clinical improvement at 3 months, with a high and expedient venous ulcer healing rate. Key words: Containment, Coronavirus, Epidemic, Outbreak, Pandemic

Outcomes of arteriovenous fistula creation: A Jordanian experience

Objective: The arteriovenous fistula is considered the preferred hemodialysis access due to its lower complication rate and longer patency. The aim of this study is to report the outcomes of arteriovenous fistula creation and to study the predictive factors for these outcomes. Study design and method: This is a retrospective study of all patients who underwent autogenous arteriovenous fistula creation procedure by a single surgeon during the period from October 2011 till December 2017. Material: All the procedures were performed at an academic referral center by a single surgeon. All patients who underwent arteriovenous fistula creation in the upper limb during the study period were included. All patients were diagnosed with end-stage renal disease and referred for arteriovenous fistula creation either before or after initiating hemodialysis. Method: Data were collected from the patients’ charts. The primary outcomes were the primary failure and secondary patency rates. Secondary outcome was to find the factors associated with decreased patency. The Kaplan–Meier curve with the log-rank test was used to describe the patency while univariate and multivariate analyses were done to the factors considered relevant to the patency. Results: The total number of procedures was 291; of which, 18 were lost to follow-up. The primary failure rate was 12%. Secondary patency rate at 1 and 5 years was 79% and 53%, respectively. Diabetes mellitus and fistulae placed on right side were associated with decreased patency. Conclusion: The primary failure rate was relatively low in this study but the long-term functionality of the arteriovenous fistulae needs to be improved.

Role of Balloon Assisted Maturation Technique in the Rate of AVF Maturation in Chronic Renal Failure Patients

Background the current recommendations from the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKFDOQI) favors the use of arteriovenous fistulas (AVF) over grafts and central catheters, in an effort to decrease cost, increase long term patency, reduce interventions and decrease patient morbidity. Purpose this study was designed to determine the rate of AVF maturation using the (BAM) technique; the primary and secondary patency rate and to evaluate the feasibility and safety of the (BAM) technique for the immature or failed AVF. Patients and Methods 30 chronic renal failure patients were selected for the purpose of this study from patients presented to vascular surgery clinic, Ain Shams University Hospital and Nasr City Hospital. Results this study included 30 arteriovenous fistula, belonging to 30 chronic renal failure patient. Their mean age was 57.6 years (±14.6). The demographic characteristics and risk factor distribution are shown below. Conclusion endovascular techniques have an important role to play in helping the dialysis community meet the goals of the Fistula First Initiative. To meet these goals, the previously mentioned techniques need to be used in varying degrees to salvage &gt; 95% of the nearly 60% of AVFs that fail to mature. When prolonged catheter time is taken into account, it is imperative to have a systematic method for salvaging these failing accesses before catheter-related complications are encountered.