Superficialization methods of arteriovenous fistula in obese patients: a review of the literature: Arteriovenous fistula in obese patients

Management of depth to achieve timely arteriovenous fistula utilization

OBJECTIVE

Failure to achieve timely arteriovenous fistulae (AVFs) utilization due to excessive depth (>6 mm) remains an ongoing concern for dialysis access. This study evaluates the outcomes of radiocephalic (RCF) and brachiocephalic (BCF) fistula elevation required for access utilization.

METHODS

A retrospective review of all patients undergoing first-time autologous access over 10 years was undertaken. RCF and BCF were analyzed, and cases of initial access failure due to depth alone were selected for study. Primary and staged brachio-basilic AVF were excluded. Outcomes of early thrombosis, line placement, maturation (successful progression to hemodialysis [HD), reintervention, and functional dialysis (continuous HD for 3 consecutive months) were examined.

RESULTS

From January 2012 to December 2022, 1733 patients (67% female; mean age, 61 ± 14 years) underwent autologous AVF placement. Of these, 298 patients (17%) had depth-related AVF access issues (BCF, 71% and RCF, 29%). Nineteen percent of these AVFs underwent a primary balloon-assisted maturation (BAM), and 2% had side branch coil embolization before consideration for elevation. The average time to intervention for depth was 11 ± 4 weeks after primary creation. During elevation, side branch ligation occurred in 38% of cases, and 15% underwent intraoperative BAM, The pre-elevation depth was 8.2 ± 3.1 mm, and the mean post-elevation depth was 4.7 ± 2.9 mm (P = .002). Early thrombosis (<18 days) occurred in 4% of cases. There was no mortality, and the 30-day major adverse cardiac event rate was 2%, with a 30-day morbidity of 5%, which was driven by wound issues. Six percent of the AVFs underwent follow-up BAM within 3 months. Mean maturation of the AVFs was 74% ± 3% vs 72% ± 3% (P = .58) for the elevation vs no-elevation groups at 24 weeks, respectively. However, there was an increase in tunneled central line placement in pre-emptive fistula patients due to the delay in maturation (elevation, 17% vs no-elevation, 8%; P = .008). There was a mean successful access time of 6 ± 3 weeks after elevation (16 ± 4 weeks after access creation). There was a median of 2.4 secondary interventions per year after elevation compared with a median of 2.7 secondary interventions per year without elevation. Mean access functionality was 68% ± 8% vs 75% ± 8% at 3 years for the elevation vs no-elevation groups, respectively (P = .25).

CONCLUSIONS

Elevation of deep BCF and RCF occurs late after placement but can be successfully achieved with low morbidity and satisfactory long-term functionality. It results in an increase in tunneled central line placement in pre-emptive fistula patients. Elevation is a valuable adjunct to AVF maturation and enhances an autologous access policy.

Lipectomy as an alternative for superficialization of autologous AVF in obese patients: experience of a referral center in Amazon

Background

The preferred vascular access for hemodialysis is a native arteriovenous fistula (AVF) because it offers the best results in the short and long terms, lower morbidity and mortality, and has additional advantages in relation to central venous catheters or arteriovenous grafts. However, obesity can present an additional challenge because of the barrier of subcutaneous cellular tissue covering the surface of the vein to be punctured.

Objectives

The authors review their experience with excision of subcutaneous tissue (lipectomy) overlying upper arm cephalic vein arteriovenous fistulas in obese patients.

Methods

Consecutive vascular access patients undergoing lipectomy for cannulation with difficult access because of vein depth were reviewed. Cephalic vein depth was measured by ultrasound in all cases.

Results

Twenty-two patients were reviewed (15 men and 7 women), with a mean body mass index of 34.0 kg/m2 (range: 28-40 kg/m2). Mean age was 58.4 years. The mean preoperative vein depth of 7.9 mm (range: 7.0-10.0 mm) was reduced to 4.7 mm (range: 3.0-6.0 mm) (P 0.01). The mean follow-up period for patients was 13.2 months. Four patients were lost to follow-up and four died during the period due to causes unrelated to vascular access.

Conclusions

Obesity should not be a limiting factor to creation of a native AVF, since lipectomy is a relatively simple option for superficialization, enabling functioning native and deep arteriovenous fistulas in obese patients.

Obesity drives secondary procedures to achieve access maturation in end-stage renal disease

BACKGROUND

Establishing long-term arteriovenous access is an important component in the long-term care of a patient with end-stage renal disease. The increasing frequency of obesity is reported to impact the access management of end-stage renal disease patients. This study aims to evaluate the outcomes of arteriovenous fistulae (AVF) in obese and nonobese patients.

METHODS

A retrospective review of all patients over ten years with primary autogenous AVF (radiocephalic, brachiocephalic, and brachial-basilic) was undertaken at a single center. Patients were subcategorized by body mass index into nonobese, class I, II, and III obesity. Outcomes of maturation (successful progression to hemodialysis), reintervention, functional dialysis (continuous hemodialysis for 3 consecutive months), and patency were examined.

RESULTS

From January 1999 to December 2019, 2311 patients (67% female; mean age, 61 ± 15 years) underwent primary AVF placement (12% radiocephalic, 53% brachiocephalic, and 35% brachial basilic). Forty-one percent were nonobese, 29% had class I obesity, 19% had class II obesity, and 11% had class III obesity. The majority of patients were diabetic and Hispanic. The 30-day major adverse cardiovascular event rate was elevated in class II (0.20%) and class III (0.50%) obesity compared with class I obesity (0.15%) and nonobese (0.05%). The 30-day morbidity rate was higher in all classes of obesity (0.5% vs0.3% vs 0.2% vs 0.05% for class III vs class II vs class I obesity and nonobese, respectively). Early thrombosis was significantly increased in class II (9%) and class III obesity (12%) compared with class I obesity (5%) and nonobese (3%). There was a two-fold increase in procedures to effect maturation in class II (51%) and class III (74%) obesity compared with class I obesity (22%) and nonobese (34%). Secondary patency at 3 years was significantly lower in class III (62 ± 4%) and class II (79 ± 3%) compared with class I obesity (87 ± 2%) and nonobese (93 ± 4%). All classes of obesity required significantly more secondary Interventions per year compared with nonobese (3.9 vs 3.1 vs 2.5 vs 1.4 secondary interventions per year for class III vs class II vs class I obesity and nonobese, respectively).

CONCLUSIONS

Advancing obesity class is associated with an increased number of procedures to achieve AVF maturation and is associated with poorer patency and functionality as the category of obesity advances.

Predictors of Arteriovenous Fistula Maturation among Patients with Severe Obesity

BACKGROUND

There is an increasing prevalence of obesity among patients who develop end-stage renal disease and require dialysis. While referrals for arteriovenous fistulas (AVFs) among patients with class 2-3 obesity (i.e., body mass index [BMI] ≥ 35) are increasing, it is unclear what type of autogenous access is most likely to mature in this patient population. This study was designed to evaluate factors that impact maturation of AVF among patients with class ≥2 obesity.

METHODS

We retrospectively reviewed AVFs created at a single center from 2016 to 2019 for patients who had undergone dialysis within the same healthcare system. Ultrasound studies were used to evaluate factors that defined functional maturation, including diameter, depth, and volume flow rates through the fistula. Logistic regression models were used to evaluate the risk-adjusted association between class ≥2 obesity and functional maturation.

RESULTS

A total of 202 AVFs [radiocephalic (24%), brachiocephalic (43%), and transposed brachiobasilic (33%)] were created during the study period, of which 53 (26%) patients had a BMI >35. Functional maturation was significantly lower among patients with class ≥2 obesity undergoing brachiocephalic (58% obese versus 82% normal-overweight; P = 0.017), but not radiocephalic or brachiobasilic AVFs. This was primarily a result of excessive AVF depth in severely obese patients (9.6 ± 4.0 mm obese versus 6.0 ± 2.7 mm normal-overweight; P < 0.001), whereas there was no significant difference found in average volume flow or AVF diameter between groups. In risk-adjusted models, a BMI ≥35 was associated with a significantly lower likelihood of achieving AVF functional maturation (odds ratio: 0.38; 95% confidence interval: 0.18-0.78; P = 0.009) after controlling for age, sex, socioeconomic status, and fistula type.

CONCLUSIONS

Patients with a BMI >35 are less likely to mature AVFs after creation. This principally affects brachiocephalic AVFs and occurs because of increased fistula depth as opposed to diameter or volume flow parameters. These data can help guide decision-making when planning AVF placement in severely obese patients.