Establishing an autogenous vascular access program in a Guatemalan comprehensive pediatric nephrology center.

BACKGROUND: The Guatemalan Foundation for Children with Kidney Diseases collaborated with Bridge of Life, a not-for-profit charitable organization, to establish a vascular access program. We reviewed our experience with graded surgical responsibility and structured didactic training, creating arteriovenous fistulas (AVF) for Guatemalan children. METHODS: Pediatric vascular access missions were completed from 2015 to 2023 and analyzed retrospectively. Follow-up was completed by the Guatemalan pediatric surgeons, nephrologists, and nursing staff. AVF patency and patient survival were evaluated by Kaplan-Meier life-table analysis with univariate and multivariable association between patient demographic variables by Cox proportional hazards models. RESULTS: Among a total of 153 vascular access operations, there were 139 new patient procedures, forming the study group for this review. The mean age was 13.6 years, 42.6% were female, and the mean BMI was 17.3. Radial or ulnar artery-based direct AVFs were established in 100 patients (71.9%) and ten of the 25 transposition procedures. Brachial artery inflow was required in 29 direct AVFs (20.9%). Two patients underwent femoral vein transpositions. Access-related distal ischemia was not encountered. Seven of the AVF patients later required access banding for arm edema; all had previous dialysis catheters (mean = 9, range 4-12). Primary and cumulative patency rates were 84% and 86% at 12 months and 64% and 81% at 24 months, respectively. The median follow-up was 12 months. Overall patient survival was 84% and 67% at 12 and 24 months, respectively. There were no deaths related to AVF access. CONCLUSIONS: Safe and functional AVFs were established in a teaching environment within a Guatemalan comprehensive pediatric nephrology center.

Comparison of surgical versus percutaneously created arteriovenous hemodialysis fistulas.

OBJECTIVE: The aim of the present study was to compare the results between percutaneous arteriovenous fistulas (p-AVFs) created with the Ellipsys device (Ellipsys Vascular Access System; Avenu Medical, San Juan Capistrano, Calif) and surgical arteriovenous fistulas (s-AVFs). METHODS: A single-center retrospective comparative study of the first 107 patients who had undergone p-AVF creation with the Ellipsys system from May 2017 to May 2018 with an equal number of consecutive patients who had undergone s-AVF creation in our center during the same period. The primary endpoints included the maturation and patency rates. The secondary endpoints were reintervention, risk of infection, and the incidence of steal syndrome and aneurysm formation. RESULTS: The demographic, hypertension, and diabetes data were similar for both groups. The only difference between the two groups was that more p-AVF patients had already been receiving hemodialysis (61% vs 47%; P < .05). The p-AVFs showed superior maturation rates at 6 weeks (65% vs 50%; P = .01). The primary patency rates were greater for the s-AVFs at 12 months (86% vs 61%; P < .01). However, primary patency was comparable between the two groups at 24 months (52% vs 55%; P = .48). No significant difference was found in the secondary patency rates at 12 (90% vs 91%) and 24 (88% vs 91%) months. At the 2-year follow-up point, the rate of percutaneous reintervention was similar; however, the s-AVFs had required more frequent surgical revision (36% vs 17%; P = .01). Issues with wound healing and infection were also more frequent with s-AVFs (9% vs 0.9%; P < .01). CONCLUSIONS: Fistulas created percutaneously with the Ellipsys system showed superior maturation rates and similar patency with s-AVFs created in an experienced high-volume vascular surgery practice. p-AVFs had a lower risk of wound healing issues, infection, and surgical revision. Larger, prospective, randomized multicenter studies are needed to confirm these findings.

Paclitaxel-Coated Balloons for the Treatment of Symptomatic Central Venous Stenosis in Vascular Access: Results From a European, Multicenter, Single-Arm Retrospective Analysis.

INTRODUCTION: This was a European, multicenter, investigator-initiated and run, single-arm retrospective analysis to assess the safety and the clinical benefit of the use of paclitaxel-coated balloon (PCB) for the treatment of symptomatic central venous stenosis (CVS). MATERIALS AND METHODS: Eleven centers from 7 countries across Europe, submitted 86 cases performed during the period between October 2015 and June 2018. Minimum follow-up was 6 months. Patient baseline demographics and procedural details were collected. Mean age was 62.6 years (SD 15.2 years). Median vascular access age was 3.0 years (IQR 1.2-4.8 years). A total of 55 were arteriovenous fistulas (64%) the rest arteriovenous grafts (31/86, 36%). Vessels treated were 43 subclavian veins, 42 brachiocephalic veins and 1 superior vena cava. Median drug-coated balloon diameter was 10 mm (IQR 8-12 mm). Primary outcome measures were clinically assessed intervention-free period (IFP) of the treated segment at 6 months and procedure-related minor and major complications. Secondary outcome measures included access circuit survival, patient survival, and the investigation of independent factors that influence the IFP. RESULTS: IFP was 62.7% at 6 months. Median patient follow-up time was 1.0 year (IQR 0.5-2.2 years). There was 1 minor complication (1/86; 1.2%) and no major complications. Access circuit survival was 87.7% at 6 months. Patient survival was 79.7% at 2 years according to Kaplan-Meier survival analysis. Higher balloon diameters significantly favored IFP [HR 0.71 (0.55-0.92), p=0.006; 5-7 mm group vs 8-12 mm group, p=0.025]. CONCLUSION: In this analysis, use of PCBs for the treatment of symptomatic CVS was safe. Efficacy was comparable to previous trials. Increased balloon size had a significant effect on patency rates.

Midterm results of percutaneous arteriovenous fistula creation with the Ellipsys Vascular Access System, technical recommendations, and an algorithm for maintenance.

OBJECTIVE: The aim of this study was to report our midterm results of percutaneous arteriovenous fistula (pAVF) creation using the Ellipsys (Avenu Medical, San Juan Capistrano, Calif) device and to present technical recommendations and our algorithm of pAVF maintenance. METHODS: A single-center comprehensive database of all consecutive predialysis and end-stage renal disease patients who had a pAVF creation with the Ellipsys device was reviewed retrospectively. Study end points included technical success, maturation, functional patency, and required interventions. RESULTS: Between May 2017 and July 2019, there were 234 patients (mean age, 64 years; 148 male [63%]) who had a pAVF created. Technical success was achieved in 232 individuals (99%), and average duration of the procedure was 15 minutes (7-35 minutes). Average follow-up was 252 days (range, 83-696 days). The 1-year primary, primary assisted, and secondary patency rates were 54%, 85%, and 96%, respectively. Average pAVF flow was 923 mL/min (range, 425-1440 mL/min). There were no significant adverse events related to the procedure. Only three patients (1%) required a later conversion of the pAVF anastomosis to a surgical fistula. Twenty-four (10%) patients required superficialization of deep outflow veins because of difficult cannulation. Average maturation time was 4 weeks (range, 1-12 weeks). Fourteen patients (6%) had early (<2 weeks after creation) cannulation of the pAVF. CONCLUSIONS: The Ellipsys pAVF device allows the rapid and safe creation of a reliable autogenous access. Rates of technical success, patency, and maturation were excellent. For patients unsuited for a distal radiocephalic arteriovenous fistula, it should be considered the next preferred access option.

Creating arteriovenous fistulas for children in Guatemala.

OBJECTIVE: The Guatemalan Foundation for Children with Kidney Diseases was established in 2003 as the first and only comprehensive pediatric nephrology program and hemodialysis unit in Guatemala. Bridge of Life (BOL) is a not-for-profit charitable organization focused on chronic kidney disease and supplied equipment, training and support during formation of the hemodialysis unit. Pediatric permanent vascular access (VA) expertise had not been established and noncuffed dialysis catheters provided almost all VA, many through subclavian vein access sites. BOL assistance was requested for establishing a VA surgical program, resulting in recurring BOL surgical missions to create arteriovenous fistulas (AVF) in these children. This study analyzes the BOL pediatric VA missions to Guatemala. METHODS: Three surgical pediatric VA missions were conducted in Guatemala from 2015 to 2017. Each mission was led by two or three surgeons. All supplies and equipment (including ultrasound units) were taken as part of each mission. The BOL surgical VA mission teams work with local pediatric surgeons, pediatric nephrologists, and dialysis nurses to establish collegial relationships and foster teaching interactions. We retrospectively reviewed the patient demographic data, procedures, and outcomes for these missions. RESULTS: AVFs were created in 54 new pediatric patients. Ages were 8 to 19 years (13.4 ± 2.8 years) and 29 patients (54%) were male. Patient weights were 28 to 50 kg (30.8 ± 8.3 kg) with body mass indexes of 12 to 25 kg/m2 (17.9 ± 2.9 kg/m2). Radiocephalic AVFs were created in 21 children (39%), proximal radial artery AVFs in 12 (22%). and brachial artery inflow AVFs in 5 (9%). Sixteen patients (30%) required transpositions and one a translocation; two of these were femoral procedures. Primary and cumulative patency rates were 83% and 85% at 12 months and 62% and 85% at 36 months, respectively. The median follow-up was 17 months. Interventions with fistulagram and balloon angioplasty options were not available for AVF dysfunction or access salvage during the study period. However, six patients underwent an AVF revision and salvage during subsequent missions or by one of the Guatemalan surgeons (R.S.). Four individuals underwent successful transplantation during the study period. There were no operative deaths or major complications. CONCLUSIONS: Pediatric VA missions to Guatemala created safe and functional AVFs in concert with local pediatric surgeons and pediatric nephrologists. Three surgical missions included access operations in 54 new patients. Cumulative AVF patency was 85% at 36 months.

Proximal radial artery arteriovenous fistula for hemodialysis vascular access.

OBJECTIVE: This study reviewed our experience with proximal radial artery-based arteriovenous fistulas (PRA-AVFs) for hemodialysis vascular access, evaluating characteristics of the patients, functional patency, risk of steal syndrome, survival of the patient, and technical considerations. METHODS: We retrospectively analyzed our database of consecutive patients, identifying those individuals with a PRA-AVF created during a 12-year period. In addition to physical examination, all patients underwent ultrasound vessel mapping by the operating surgeon, identifying the PRA-AVF configuration and outflow target most likely to succeed. RESULTS: PRA-AVFs were created in 1396 individuals during the 12-year study period. The mean age was 59 years (standard deviation, ±15.9 years); 717 (51%) patients were women, 819 (59%) were diabetic, and 394 (28%) were obese. A transposition procedure was required in 400 patients, and 189 (47%) of these were completed in two-staged operations. Preoperative characteristics with a negative impact on PRA-AVF cumulative patency included female gender (hazard ratio, 1.90; 95% confidence interval, 1.37-2.65), obesity (hazard ratio, 1.92; 95% confidence interval, 1.40-2.65), and younger age. Dialysis-associated steal syndrome (DASS) requiring an intervention occurred in 39 (2.8%) patients, and 85% of these were diabetic. The most common procedures required to restore hand perfusion while preserving the AVF were banding and outflow branch ligation or coil occlusion to decrease access flow. DASS emerged spontaneously in 15 (1.1%) of the patients, and 24 (1.7%) individuals developed hand ischemia requiring intervention after fistulography with balloon angioplasty of the PRA-AVF anastomosis during the first years of the study period. Limiting angioplasty balloon size for such patients avoided these uncommon angioplasty-induced DASS events in later years. Primary, primary assisted, and cumulative (secondary) patency rates were 60%, 90%, and 93% at 12 months and 47%, 86%, and 91% at 24 months, respectively. Follow-up was 0.7 to 127 months (median, 25 months). CONCLUSIONS: PRA-AVFs offer excellent functional patency with low risk of dialysis access-related steal syndrome. The antecubital site has a wide range of venous outflow options for both direct PRA-AVFs and transposition procedures.

Early results of percutaneous arteriovenous fistula creation with the Ellipsys Vascular Access System.

OBJECTIVE: We reviewed our initial experience creating a percutaneous arteriovenous fistula (pAVF) using a thermal resistance anastomosis device with proximal radial artery inflow. METHODS: A retrospective review was conducted of all patients who underwent a pAVF creation procedure between May 2017 and October 2017. Primary end points of the study were technical success, patency by Doppler ultrasound examination or angiography, flow levels achieved, time to first use, and pAVF-related complications. RESULTS: A pAVF was attempted in 34 patients with technical success in 33 individuals (97%). Patency of the pAVF was 94%. Mean access flow was 946 mL/min (brachial artery measurement) at the latest follow-up visit (53-229 days; average, 141 days). At 6 weeks, all fistulas have been used or were ready for dialysis by clinical examination or ultrasound examination. Only one patient required superficialization of the upper arm cephalic vein by lipectomy. There were no adverse events related to the pAVF creation or use, nor was there need for further interventions. CONCLUSIONS: Successful pAVFs with proximal radial artery inflow were created with excellent initial results regarding technical success, patency, and safety. Advantages include avoidance of a surgical incision, short procedure times, good acceptance by patients, prompt access maturation, moderate flow, and low-pressure access, with possible reduction of risk for ischemic complications. Avoidance of vessel manipulation and side branch ligation might reduce risk of thrombosis and improve long-term patency and reduce need for further interventions. These early findings need to be confirmed in larger and longer follow-up studies.

Laser Atherectomy for the Treatment of Peripheral Arterial Disease.

BACKGROUND: The aim of the study was to investigate the clinical results of laser atherectomy in the treatment of peripheral arterial disease. METHODS: Retrospective analysis of consecutive patients underwent laser atherectomy at a single institution during a 7-year period by vascular surgeons and interventional cardiologists in a tertiary university-affiliated hospital. Clinical data were retrieved from patient charts and hospital electronic medical records along with the associated arteriograms. RESULTS: A total of 461 lesions in 343 limbs were treated in 300 patients with a mean age of 70 years. The indication was critical limb ischemia (CLI) with rest pain or tissue loss in 227 (66%) of interventions and claudication in 116 (34%). All procedures included an associated balloon angioplasty, while stenting was performed in 33%. Technical success was achieved in 99% with only 2 (<1%) cases with an acute procedure-related complication requiring surgical intervention. At a mean follow-up of 28 months (range, 1-87 months; median 24 months), 156 patients (45%) became asymptomatic or achieved significant clinical improvement (resolution of tissue loss or rest pain), 60 (17%) remained with CLI, 30 (9%) had a major proximal amputation, and 18 (5%) had a minor amputation. Freedom from major amputation was 90% at 5 years by life-table analysis. Univariate statistical analysis demonstrated the risk of a major amputation to be associated with diabetes, hemodialysis, and tissue loss (P < 0.05 to P < 0.005), while multivariate logistic regression analysis indicated diabetes to be overwhelmingly important (RR: 4.84; 95% confidence interval [CI]: 1.1-21.3; P < 0.05). In a similar manner, multivariate analysis indicated dialysis (RR: 2.46; 95% CI: 1.01-5.98; P < 0.05) and CLI (RR: 2.27; 95% CI: 1.42-3.65; P < 0.01) were associated with higher likelihood for lack of clinical improvement. There was no difference in major amputation rates between surgeons and interventional cardiologists (RR: 1.5; 95% CI: 0.7-2.1; P < 0.1) although it was 3 times more likely for the patients treated by surgeons to suffer from CLI (odds ratio: 3.2; 95% CI: 1.9-5.4; P < 0.0001). CONCLUSIONS: Laser atherectomy is a safe and useful adjunct in limb salvage. Diabetics have much higher probability of requiring a proximal amputation, while those on dialysis and with CLI are least likely to gain clinical benefit.

Axillary Artery Deployment of Endovascular Aortic Repair Iliac Limb for Preservation of Internal Iliac Artery Blood Flow.

The axillary artery approach has been used for access for complex endovascular aortic procedures such as thoracic endovascular aortic repair with poor anatomy for traditional deployment as well as for fenestrated and branched abdominal aortic endografts. We report the first case of an iliac graft limb deployment through the axillary artery during an endovascular aortic repair for maintenance of anterograde internal iliac flow in a patient with a symptomatic abdominal aortic aneurysm and chronic occlusion of both the external iliac and common femoral arteries.

Treatment of High Flow Arteriovenous Fistulas after Successful Renal Transplant Using a Simple Precision Banding Technique.

BACKGROUND: Observation versus ligation of a functional arteriovenous fistula (AVF) after successful renal transplantation (SRT) has been a controversial topic of debate. Congestive heart failure and pulmonary hypertension are common in dialysis patients, and more frequent when vascular access flow is excessive. Renal transplant failure may occur in up to 34% of patients after 5 years, therefore maintaining a moderate flow AVF appears warranted. We review SRT patients with high flow-AVFs (HF-AVF) and clinical signs of heart failure where a modified precision banding procedure was used for access flow reduction. METHODS: Patients referred for HF-AVF evaluation after SRT were identified and records reviewed retrospectively. In addition to recording clinical signs of heart failure, each patient had ultrasound AVF flow measurement before and after temporary AVF occlusion of the access by digital compression. Pulse rate and the presence or absence of a cardiac murmur was noted before and after AVF compression. Adequacy of access flow restriction was evaluated intraoperatively using ultrasound flow measurements, adjusting the banding diameter in 0.5 mm increments to achieve the targeted AVF flow. RESULTS: Twelve patients were evaluated over a 19-month period. Eight (66%) were male and one (8%) obese. Ages were 15-73 years (mean = 42). The AVFs were established 24-86 months previously. The mean pulse rate declined after AVF compression from 90/min to 72/min (range 110-78). Six patients had a precompression cardiac flow murmur that disappeared with temporary AVF compression. One patient with poor cardiac function underwent immediate AVF ligation with dramatic improvement in cardiac status. All other patients underwent a precision banding procedure with real-time flow monitoring. Mean access flow was 2,280 mL/min (1,148-3,320 mL/min) before access banding and was 598 mL/min (481-876) after flow reduction. The clinical signs of heart failure disappeared in all patients. All AVFs remained patent although one individual later requested ligation for cosmesis. Two patients had renal transplant failure and later successfully used the AVF. Follow-up postbanding was 1-18 months (mean = 12). CONCLUSIONS: Patients with successful renal transplants and HF-AVFs had resolution of heart failure findings and maintenance of access patency using a modified precision banding procedure. Flow reduction in symptomatic renal transplant patients with elevated access flow is recommended. Further study is warranted to substantiate these recommendations and clarify the appropriate thresholds for such interventions.