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.

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

BACKGROUND

The creation of an arteriovenous fistula (AVF) in obese patients with end-stage-renal-disease, might not lead to a successful hemodialysis session, partly due to excess adipose tissue overlapping the enlarged vein. This review summarizes the available evidence on superficialization methods in studies dealing with obese patients.

METHODS

An English-language literature search was undertaken in the MEDLINE/SCOPUS databases looking for publications that described procedures of salvaging autologous arteriovenous access in upper extremities of obese patients. Perioperative outcomes including technical and clinical success, mean vein depth reduction, wound complications and patency rates were compared within all identified techniques.

RESULTS

We identified 12 prospective and 8 retrospective studies. A total of 1149 patients with a mean age 57.2 (range: 49-68) years and a mean BMI 35.8 (range: 28.2-40.8) kg/m² underwent mainly radial-cephalic and brachial-cephalic AVF superficialization procedures [transposition, 54%; elevation, 11.1%; lipectomy, 26.1%; liposuction, 2.4%; implantation of a venous window needle guide device, 6.4%]. Technical success was similar between all methods (≥ 96%). However, successful cannulation was lower after liposuction and elevation (81.5 and 78.1% respectively). Transposition achieved lower mean vein depth reduction and clinical success when compared with lipectomy (4.9mm vs 8.8mm and 90% vs 92,7% respectively). Transposition and liposuction had the lowest and highest complication rate respectively (1.6% vs 40.8%). Primary and secondary patency rates were lower with liposuction (51.8 and 76.6% respectively), while lipectomy and elevation achieved the highest primary patency rates (68.3% and 71.6% respectively) at 12 months.

CONCLUSIONS

In obese patients, all superficialisation techniques report high technical success rates. Although limited by the design of individual published studies and lack of a standard for reporting outcomes, these results lead to satisfactory postoperative and early outcomes. In aggregate, lipectomy and transposition are more clinically effective and more durable procedures.

Dialysis of the Obese Patient: Meeting Needs for a Growing Epidemic

Increasing population obesity and associated metabolic consequences has led to increased number of obese patients with chronic kidney disease and end-stage renal disease. While obesity is associated with increased cardiovascular morbidity and mortality, obese dialysis patients present a seeming paradox for survival benefit, given other acute intervening illnesses for those on dialysis with loss of lean body mass overtime. Challenges remain in providing adequate renal replacement options and therapy for this growing segment of obese patients on dialysis which are discussed in this article.

Center-Effect of Incident Hemodialysis Vascular Access Use: Analysis of a Bi-national Registry

Background

Commencing hemodialysis (HD) with an arteriovenous access is associated with superior patient outcomes compared with a catheter, but the majority of patients in Australia and New Zealand initiate HD with a central venous catheter. This study examined patient and center factors associated with arteriovenous fistula/graft access use at HD commencement.

Methods

We included all adult patients starting chronic HD in Australia and New Zealand between 2004 and 2015. Access type at HD initiation was analyzed using logistic regression. Patient-level factors included sex, age, race, body mass index (BMI), smoking status, primary kidney disease, late nephrologist referral, comorbidities, and prior RRT. Center-level factors included size; transplant capability; home HD proportion; incident peritoneal dialysis (average number of patients commencing RRT with peritoneal dialysis per year); mean weekly HD hours; average blood flow; and achievement of phosphate, hemoglobin, and weekly Kt/V targets. The study included 27,123 patients from 61 centers.

Results

Arteriovenous access use at HD commencement varied four-fold from 15% to 62% (median 39%) across centers. Incident arteriovenous access use was more likely in patients aged 51-72 years, males, and patients with a BMI of >25 kg/m2 and polycystic kidney disease; but use was less likely in patients with a BMI of <18.5 kg/m2, late nephrologist referral, diabetes mellitus, cardiovascular disease, chronic lung disease, and prior RRT. Starting HD with an arteriovenous access was less likely in centers with the highest proportion of home HD, and no center factor was associated with higher arteriovenous access use. Adjustment for center-level characteristics resulted in a 25% reduction in observed intercenter variability of arteriovenous access use at HD initiation compared with the model adjusted for only patient-level characteristics.

Conclusions

This study identified several patient and center factors associated with incident HD access use, yet these factors did not fully explain the substantial variability in arteriovenous access use across centers.

Management of Obesity in Adults with CKD

Obesity is a leading public health problem that currently affects over 650 million individuals worldwide. Although interest in the adverse effects of obesity has grown exponentially in recent years, less attention has been given to studying its management in individuals with CKD. This relatively unexplored area should be considered a high priority because of the rapid growth and high prevalence of obesity in the CKD population, its broad impact on health and outcomes, and its modifiable nature. This article begins to lay the groundwork in this field by providing a comprehensive overview that critically evaluates the available evidence related to obesity and kidney disease, identifies important gaps in our knowledge base, and integrates recent insights in the pathophysiology of obesity to help provide a way forward in establishing guidelines as a basis for managing obesity in CKD. Finally, the article includes a kidney-centric algorithm for management of obesity that can be used in clinical practice.

Multicentre Study on the Efficacy of Brachial Artery Transposition Among Haemodialysis Patients

OBJECTIVE

Brachial artery transposition (BAT) is not a well known method for obtaining vascular access (VA) for maintenance haemodialysis. This study evaluated the outcomes of BAT.

METHODS

This multicentre retrospective cohort study included 233 consecutive patients who underwent BAT between January 2012 and December 2013. The indications were inadequate vessels for obtaining VA, severe heart failure, hand ischaemia, central vein stenosis/occlusion, or a history of catheter/graft infection. The transposed brachial artery was used only for arterial inflow and other routes were used for outflow.

RESULTS

BAT was successful in 227 patients, and adequate blood flow was achieved during dialysis sessions. The first successful cannulation was after a median of 18 days. BAT was performed using superficial veins as the return route in 127 patients and arteriovenous fistula (AVF) creation in 63 patients to prevent maturation failure. In 41 patients with central venous catheterisation, the transposed brachial artery was used for arterial inflow. The complications of BAT were impaired wound healing in 14 patients, including skin necrosis in two; large aneurysms in six, including a mycotic pseudo-aneurysm in one; arterial thrombosis in five; hand ischaemia in five; lymphorrhoea in four; and haematoma/bleeding in three. The transposed brachial artery was abandoned in four, three, three, and one case of arterial thrombosis/stenosis, haematoma/bleeding, skin necrosis, and large aneurysm, respectively. Access to the return routes failed in 48 cases because of vein damage caused by cannulation in 22, AVF thrombosis/stenosis in 14, catheter infection in six, and catheter occlusion in six. At two years, the primary patency rates of the transposed brachial artery and access circuit were 88% and 54%, respectively.

CONCLUSION

BAT is a safe and effective technique. The patency was high for the transposed brachial artery but adequate for the access circuit. BAT can be considered for patients with an unobtainable standard arteriovenous access.

Higher body mass index is associated with reinterventions and lower maturation rates after upper extremity arteriovenous access creation

OBJECTIVE

A patient's body mass index (BMI) can affect both perioperative and postoperative outcomes across all surgical specialties. Given that obesity and end-stage renal disease are growing in prevalence, we aimed to evaluate the association between BMI and outcomes of upper extremity arteriovenous (AV) access creation.

METHODS

A retrospective single-institution review was conducted for AV access creations from 2014 to 2018. Patient demographics, comorbidities, and AV access details were recorded. BMI groups were defined as normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (30-39.9 kg/m²), and morbidly obese (>40 kg/m²). Perioperative complications and long-term outcomes including access maturation (defined as access being used for hemodialysis or the surgeon's judgment that access was ready for use in patients not yet on hemodialysis), occlusion, and reintervention were evaluated.

RESULTS

A total of 611 upper extremity AV access creations were performed on patients who were normal weight (29.6%), overweight (31.3%), obese (29.6%), and morbidly obese (9.5%). Access type included brachiocephalic (43.2%), brachiobasilic (25.5%), and radiocephalic (14.2%) fistulas and AV grafts (14.2%). Median age was 60.9 years, and 59.6% were male. Univariable analysis showed no difference between BMI groups for perioperative steal, hematoma, home discharge, or 30-day primary patency. Freedom from reintervention at 2 years on Kaplan-Meier analysis differed by BMI (44.5% ± 4.6% normal weight, 29% ± 3.8% overweight, 39.8% ± 4.3% obese, 34.7% ± 8% morbidly obese; P = .041). There was no difference in 2-year freedom from new access creation or survival. AV access maturity within 180 days differed between BMI groups (74.3% normal weight, 66% overweight, 65.7% obese, 46.6% morbidly obese; P < .001). On multivariable analysis, failure to mature within 180 days was associated with overweight (odds ratio [OR], 1.93; 95% confidence interval [CI], 1.14-3.29; P = .002), obese (OR, 2.12; 95% CI, 1.19-3.47; P = .009), and morbidly obese (OR, 3.68; 95% CI, 1.85-7.3; P < .001) relative to normal weight BMI. AV access reintervention was associated with overweight (hazard ratio [HR], 1.83; 95% CI, 1.34-2.5), obese (HR, 1.56; 95% CI, 1.12-2.16), and morbidly obese (HR, 1.69; 95% CI, 1.1-2.58; P = .02) relative to normal weight BMI. BMI was not independently associated with long-term readmission or survival.

CONCLUSIONS

Obesity is associated with higher rates of AV access failure to mature and reintervention. Surgeons performing access creation on obese patients must consider this for planning and setting expectations. Weight loss assistance may need to be incorporated into treatment algorithms.

Efficacy and comparison of elevation transposition and lipectomy for superficialization of cephalic arteriovenous fistula veins

OBJECTIVE

Substantial percentages of cephalic arteriovenous fistulas are situated too deep and require superficialization before use for hemodialysis. The superficialization techniques are diverse: tunnel transposition, elevation, elevation transposition, and lipectomy. Since the fistula veins are not mobilized during lipectomy, it is believed that lipectomy produces better outcomes than other techniques. However, no available report directly compares lipectomy with other techniques. The objective of this report is to compare the outcomes of cephalic elevation transposition with lipectomy.

METHODS

The clinical data of patients who underwent second-stage cephalic elevation transposition or lipectomy at an ambulatory surgery center from 2009 to 2017 were analyzed ( n = 153).

RESULTS

Comparing the cephalic elevation transposition group ( n = 125) with the lipectomy group ( n = 28), the mean body mass index was 36.8 ± 7.6 versus 38.1 ± 7.2 ( p = 0.41); the percentage of upper arm fistulas was 84% versus 61% ( p < 0.01); the mean follow-up was 20.1 ± 17.5 versus 38.6 ± 24.4 months ( p < 0.01); the primary patency rates of the whole fistula conduits were 42% versus 50% at 1 year ( p = 0.08); the secondary patency rates were 99% versus 100% at 1 year ( p = 0.22); the primary patency rates of the superficialized vein segments were 73% versus 68% at 1 year ( p = 0.72); and the mean number of percutaneous interventions required for the superficialized vein segments was 0.49 ± 1.10 versus 0.43 ± 0.71 per access-year ( p = 0.74).

CONCLUSION

Cephalic elevation transposition and lipectomy are both reliable techniques for superficialization of cephalic fistula veins and their outcomes are comparable.

One-stage operation for superficialization of native radio-cephalic fistula in obese patients

Purpose:

The population of obese patients is increasing in general and also at hemodialysis initiation. For successful cannulation of arteriovenous fistula, the National Kidney Foundation-Dialysis Outcome Quality Initiative guidelines suggest that the required maturation parameters are at a depth of <6 mm. There are several reports describing two-stage superficialization of arteriovenous fistulas in obese cases. Therefore, we investigated the utility and complications of one-stage superficialization of radio-cephalic fistula.

Methods:

From January 2011 to March 2017, we simultaneously performed forearm radio-cephalic fistula creation and superficialization of the cephalic vein for 10 patients having obesity (body mass index > 30 kg/m2) and deep cephalic vein (>6 mm). Initially, an arteriovenous anastomosis was created at an appropriate site. Subsequently, an 8–10 cm longitudinal skin incision was made along the lateral aspect of the forearm cephalic vein. The cephalic vein was identified and exposed. The cephalic vein was repositioned superficially.

Results:

The mean age of the patients was 53 years (range: 40–72 years) and the mean body mass index was 40.2 kg/m2 (33.1–59.7 kg/m2). The cause of renal failure in eight patients was diabetic nephropathy, and in two patients, it was unknown. After the procedure, vein depth became 3.4 mm (1.9–4.6 mm) from 8.2 mm (6.0–13.4 mm). All patients who initiated dialysis underwent successful two-needle cannulation. Primary patency rate was 71.4% at 12 months (two patients underwent percutaneous transluminal angioplasty) and secondary patency rate was 100%. There was one procedure-related complication and delayed wound healing, which was improved by observation without antibiotics.

Conclusion:

This small series of patients indicates that one-stage superficialization of radio-cephalic fistula is a safe and effective option to start hemodialysis in obese subjects.

Liposuction over a Shielded Arteriovenous Fistula for Hemodialysis Access Maturation

Vascular access for hemodialysis by arteriovenous fistula (AVF) is broadly recommended. Vein depth in many obese patients makes cannulation of an otherwise successful AVF difficult or impossible. We reviewed the case of an obese patient where liposuction was used to remove adipose tissue resulting in a superficial and easily accessed AVF. An endoscopic vein harvesting device was used to shield the vein during liposuction.

Maturation of arteriovenous fistula: Analysis of key factors

The growing proportion of individuals suffering from chronic kidney disease has considerable repercussions for both kidney specialists and primary care. Progressive and permanent renal failure is most frequently treated with hemodialysis. The efficiency of hemodialysis treatment relies on the functional status of vascular access. Determining the type of vascular access has prime significance for maximizing successful maturation of a fistula and avoiding surgical revision. Despite the frequency of arteriovenous fistula procedures, there are no consistent criteria applied before creation of arteriovenous fistulae. Increased prevalence and use of arteriovenous fistulae would result if there were reliable criteria to assess which arteriovenous fistulae are more likely to reach maturity without additional procedures. Published studies assessing the predictive markers of fistula maturation vary to a great extent with regard to definitions, design, study size, patient sample, and clinical factors. As a result, surgeons and specialists must decide which possible risk factors are most likely to occur, as well as which parameters to employ when evaluating the success rate of fistula development in patients awaiting the creation of permanent access. The purpose of this literature review is to discuss the role of patient factors and blood markers in the development of arteriovenous fistulae.

The sleeve method for creation of radiocephalic arteriovenous fistulas in patients with calcified vessels

INTRODUCTION

Creation of an arteriovenous fistula (AVF) in patients with advanced atherosclerotic changes of the artery is often a challenge for the physician due to difficulties in suturing the vein to the side of the frangible artery. The sleeve technique relies on advancing the end of the artery into the lumen of the vein and protecting the anastomosis by adventitial sutures.

MATERIAL AND METHODS

The sleeve technique was performed in 23 patients with chronic kidney disease stage IV and V and included hemodialysis patients. Their mean age was 60.8 ± 14.8 years and hemodialysis treatment time 49.8 ± 40.2 months. The most frequent causes of chronic kidney disease are ischemic nephropathy (43%, n = 10) and type l diabetes (21%, n = 5). Only patients with extremely advanced atherosclerotic were recruited and analyzed.

RESULTS

The primary patency rate was 67%, 59%, 44% and 28% at 6, 12, 24, and 36 months, respectively. The secondary patency rate was 67%, 61%, 50% and 37% at 6, 12, 24, and 36 months, respectively. In three patients the AVF failed directly after the operation. Delayed fistula failure occurred in seven patients. The overall success in the creation of a functioning fistula was achieved in 15 of the 23 patients (65%). No serious complications were observed.

CONCLUSIONS

In patients with calcified atherosclerotic plaques, which constitute a barrier or make it difficult to suture the vein to the side of the artery, the sleeve method may be considered as an alternative before abandoning the creation of a fistula on the forearm. The technique is much simpler than the standard end-to-side or side-to-side anastomosis.

Vascular access should be tailored to the patient

A cornerstone of hemodialysis treatment is the creation of a functional and durable dialysis vascular access. Every patient with chronic kidney disease should have a plan of renal replacement therapy and access site protection. Factors having a crucial impact on vascular access selection include age, comorbidity, vessel quality, prognosis, dialysis urgency, and surgeon's preferences. Our medical group have reviewed these factors in our patients and, based on recently published data, developed a clinical decision tree for dialysis access in the chronic kidney disease patient. Vascular access care should be patient-centered with the aim to maximize patient survival without loss of vascular access options; and not focused only the primary patency rates of dialysis access procedures.

Arteriovenous Fistula Creation by Nephrologist Access Surgeons Worldwide

Several years ago, we published an article in this journal entitled "Autologous Arteriovenous Fistula Creation by Nephrologists." The goal of that effort was to review outcomes published by nephrologist access surgeons from around the world. An attempt was also made to define the elements that were necessary for successful autologous fistula creation in hopes that they might be used by others in an effort to increase the number of and durability of autologous fistulas in the dialysis population. Our goal, here, is to update the previous information based on recently published literature to better understand the role that nephrologist access surgeons play in the care of our dialysis patients worldwide.

Obesity-related decrease in intraoperative blood flow is associated with maturation failure of radiocephalic arteriovenous fistula

OBJECTIVE

Successful arteriovenous fistula (AVF) maturation is often challenging in obese patients. Optimal initial intraoperative blood flow (IOBF) is essential for adequate AVF maturation. This study was conducted to elucidate the effect of obesity on IOBF and radiocephalic AVF maturation.

METHODS

Patients with a newly created radiocephalic AVF were included (N = 252). Obesity was defined as a baseline body mass index (BMI) ≥25 kg/m(2), and primary maturation failure was defined as failure to use the AVF successfully by 3 months after its creation. IOBF was measured immediately after construction of the AVF with a VeriQ system (MediStim, Oslo, Norway).

RESULTS

The mean BMI was 24.1 ± 3.9 kg/m(2), and the prevalence of obesity was 31.3%. Particularly, 8.3% (21 patients) had a BMI ≥30 kg/m(2). Primary maturation failure occurred in 100 patients (39.7%), and an IOBF <190 mL/min was closely associated with the risk of maturation failure (relative risk, 3.05; 95% confidence interval, 1.52-6.11). Compared with nonobese patients, obese subjects had a significantly higher prevalence of diabetes and elevated high-sensitivity C-reactive protein levels, whereas diameters of vessels were similar. When the patients were further divided into three groups as BMI <25, 25 to 29.9, and ≥30 kg/m(2), patients in the higher BMI group showed significantly lower IOBF and higher maturation failure rate. According to multivariate analysis, the statistically significant variables that determined maturation failure were obesity, previous vascular disease, increased high-sensitivity C-reactive protein levels, and IOBF <190 mL/min.

CONCLUSIONS

Obese patients had a significantly lower IOBF, and both obesity and low IOBF contributed to the primary maturation failure of AVF. Obesity-associated inflammation and atherosclerosis might play roles in this association.

Vascular access in the obese: superficialisation of native radio-cephalic and brachio-cephalic fistulae

PURPOSE

The Department of Health estimates that currently in the UK, 61.3% of the population are overweight or obese (BMI >25 kg/m2). Fistulae in the obese often fail to mature or prove inadequate to needle due to excessive depth (>6 mm). This study is a summary of our experience with brachio and radio-cephalic vein superficialisation in the obese.

METHODS

From May 2008 to October 2012, 22 patients underwent superficialisation of the cephalic vein following radio-cephalic or brachio-cephalic Arterio-venous fistula (AVF) creation. Data were obtained from a prospective database (Cyberen®) and retrospectively analysed.

RESULTS

The study included 23 AVFs in 22 patients (seven males, 15 females), of which 13 were brachio-cephalic and 10 radio-cephalic. The mean age of the patients was 56 years (median 60, range 19-78 years). The mean BMI was 36.7 kg/m2 (median 32, 25-58 kg/m2). Six-week post procedure duplex ultrasonography recorded the mean fistula depth to be 7.7 mm (median 8 mm, 5-15 mm) and mean flow rates were 961 ml/min (median 800 ml/min, 320-1968 ml/min).Of the 23, 21 fistulae matured successfully. There were no procedure-related complications. During follow-up, two patients underwent transplantation prior to fistula use and three patients died of unrelated causes. The remaining 16 fistulae remain in use and under access surveillance.

CONCLUSIONS

Superficialisation of brachio/radio-cephalic fistulae is an excellent option to optimise the cephalic vein for needling, assisting primary patency. Superficialisation of the cephalic vein helps maintain long-term functional access in overweight and obese patients.

Liposuction for Superficialization of Deep Veins after Creation of Arteriovenous Fistulas

Purpose

Many individuals with end-stage renal disease (ESRD) have adequate arteries and veins for construction of an arteriovenous fistula (AVF) but the fistula may be too deep to cannulate because of overlying adipose tissue. This study evaluated the safety and efficacy of liposuction to superficialize deep AVFs.

Methods

Between September 2009 and January 2011, 13 patients participated in the study. Mean body mass index (BMI) was 39.1 kg/m2. The study was limited to brachiocephalic and radiocephalic fistulas. Mean fistula depth was 8.1 mm. The primary endpoint was the date of the first successful cannulation with two 17-gauge needles. Patients were followed for 12 mo.

Results

Eleven subjects (85%) underwent successful two-needle cannulation a mean of 33.7 days after the procedure. One patient died of endocarditis and one developed a hematoma and wound necrosis that required surgical elevation to enable cannulation. Projection and palpability of the fistulas tended to increase over time. Mean tissue removed was 243 mL and correlated positively with the number of days to cannulation (r=0.74, p=0.01). Greater BMI correlated positively with more surgical site complications and delays in cannulation. At 12 mo, primary patency after liposuction was 50% and secondary patency was 83%.

Conclusions

Most subjects had prompt, uncomplicated cannulation but a few had wound necrosis, large hematomas and prolonged time until cannulation. Liposuction is effective in enabling cannulation of deep vein fistulas but because of the substantial risk of serious surgical site complications, it may not be the ideal method.

Obesity as a predictor of vascular access outcomes: analysis of the USRDS DMMS Wave II study

Arteriovenous fistulae (AVF) are widely regarded as the preferred vascular access in hemodialysis patients due to their primary patency and patient survival benefits. While the obesity paradox has been associated with improved cardiovascular morbidity and all-cause mortality in dialysis patients, its long-term vascular access outcomes are less clear. Recent literature has suggested that obese patients may have increased early and late fistula failure. The purpose of this study was to explore the relationships between obesity and vascular access outcomes. We performed a retrospective cohort analysis using the USRDS DMMS Wave 2 data set. All incident dialysis patients as of January 1, 1996, over the age of 18, receiving only hemodialysis as mode of renal replacement therapy were eligible for inclusion. Among other variables, data collected for the DMMS Wave 2 included: type and location of vascular access, AVF maturity, vascular access revision, and failure. Logistic regression analyses were used to examine the relationships between obesity and vascular access outcomes, adjusting for important covariates. In all, 1486 hemodialysis patients were included. Using body mass index (BMI) <30 kg/m(2) as reference, obesity did not emerge as a factor in predicting vascular access revisions or failures. An increased risk of AVF failure to mature was found only in the highest BMI quartile (>or=35 kg/m(2)) (aOR 3.66 [95% CI 1.27-10.55], p = 0.017). Peripheral vascular disease was independently associated with an increased risk of AVF failure (aOR 2.78 [95% CI 1.01-7.63], p = 0.047) and arteriovenous graft (AVG) failure (aOR 1.65 [95% CI 1.03-2.64], p = 0.036). Obesity was not associated with increased AVF or AVG revision rates or failure and only associated with poorer AVF maturity at highest BMI quartile. We conclude that obesity should not preclude placement of AVF as vascular access of choice, except in the very obese where assessment should be individually based.