When Arteriovenous Fistulas Are Too Deep: Options in Obese Individuals

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.

Anti-obesity pharmacotherapy in adults with chronic kidney disease

Obesity is a leading risk factor for the development and progression of kidney disease and a major barrier to optimal management of patients with chronic kidney disease. While in the past anti-obesity drugs offered only modest weight loss efficacy in exchange for various safety and tolerability risks, a wave of safer, more tolerable, and more effective treatment options is transforming the management of obesity. This review evaluates current and future pharmacologic anti-obesity therapy in adults through a kidney-oriented lens. It also explores the goals of anti-obesity treatment, describes the underlying putative mechanisms of action, and raises important scientific questions that deserve further exploration in people with chronic kidney disease.

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.

Creating reverse flow arteriovenous fistulas with a forearm cannulation target

BACKGROUND

Establishing a forearm arteriovenous fistula (AVF) offers preferred cannulation sites and preserves proximal access opportunities. When a radiocephalic AVF at the wrist is not feasible and the upper arm cephalic and median cubital veins are inadequate, an AV graft or more complex access procedure is often required. Creating a retrograde flow forearm AVF (RF-AVF) is a valuable alternative where the mid-forearm median antebrachial or cephalic vein is adequate, offering forearm cannulation zones with AVF outflow through deep and superficial collaterals. We report our technique and results.

METHODS

We retrospectively reviewed our vascular access data base of consecutive patients during an 11-year study period where a RF-AVF established the only available cannulation target in the forearm. In addition to physical examination, all patients had ultrasound vessel mapping.

RESULTS

A forearm access was established with a RF-AVF as the only opportunity for cannulation in 48 patients. Ages were 14-86 years (median = 62 years). Forty-four percent female, 63% diabetic, 13% obese, and 29% had previous access operations. Inflow was proximal radial artery in 47 individuals and one proximal ulnar. Nine AVFs (19%) failed at 2-66 months (median 14 months). One RF-AVF was ligated due to arm edema. Follow-up was 2-111 months (median = 23.5 months). Primary and cumulative patency rates were 62% and 91% at 12 months, and 46% and 85% at 24 months. Five patients were lost to follow-up with functioning RF-AVFs (mean 41 months). Twenty-three patients (48%) died during F/U of causes unrelated to access procedures (mean 25 months).

CONCLUSIONS

Establishing a reverse flow forearm AVF offers a successful autogenous access option in the forearm for selected patients with an inadequate distal radial artery and/or cephalic vein at the wrist, avoiding more complex or staged procedures and preserving upper arm sites for future use. A proximal radial artery inflow procedure is recommended.

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.

Early Experience with Sine Wave Technique for Superficialization of a difficult to cannulate Arterio Venous Fistula

OBJECTIVE

To highlight safety and efficacy of sine wave technique (SWT) in superficializing deep arterio venous fistula (AVF) and managing infiltrations and other complications.

METHODS

It is a single center observational study done from Jul 2017 to July 2020. All successive cases of deep AVFs, aneurysm / pseudoaneurysms of AVFs, and AVFs requiring open venoplasty were managed with SWT. Data was collected prospectively and analyzed. SWT is based on random pattern skin flaps. Using ultrasound, a line is marked on either side of centre line (AVF) at a distance of approximately 1.5-2 cm. A sine wave is drawn starting from either of the lines to the other with multiple crests and troughs. The base of flap should be double the height of the flap, that is, about 3-4 cm. Skin is incised and flaps are raised at level of AVF. Excess fat is removed. A sliver of unhealthy skin can be sacrificed if required. Flaps are sutured back to restore sine wave continuity.

RESULTS

SWT was used in a total of eleven patients. Median age was 58 years (range 10-67 years). Eight were females and three males. One was radio-cephalic and rest were brachio-cephalic AVFs. Eight AVFs were deep with median depth of 10.25mm (range 8-13mm), median body mass index of 25.5 kg/m² (range 23.9-26.5kg/m²), median vein diameter of 7 mm (range 6-8 mm), and median flow rate of 1137.5ml/min (range 650- 1380 ml/min). Out of eight, four AVFs presented with infiltration. In other three, SWT was used for exposing AVF to treat underlying pathology (one case each of aneurysm, pseudoaneurysm & stenosis). Ten cases were done under local or regional anesthesia and one under general anesthesia. There was no peri-operative mortality or loss of AVF. Transient limb oedema developed in one case. Median time to cannulate was 20 days (range 13-28 days). Median follow up was 13 months (range 6 - 31months). Cumulative patency at 18 months was 90% (95% CI 47.3%-98.53%) and 45 % (95% CI 9.9%-87.1%) at 24months and at the end of the study.

CONCLUSION

SWT is safe and effective in superficialization of deep / difficult to cannulate AVF as well a good approach to treat complications like infiltration. Post procedure cannulation time is reasonably short.

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.

[Complications of permanent vascular access for haemodialysis]

Permanent vascular access is the basis of renal replacement therapy by the method of programmed haemodialysis, on whose stable functioning depends the life of patients with end-stage renal disease. At the present time, there is significant deficit of scientific and methodological Russian-language literature on this problem, with no Russian consensus documents concerned. This article is a review of the contemporary world literature dedicated to the problem of permanent vascular access, including currently in force European (2018) and North American (2019) guidelines for good clinical practice, also discussing the problems of strategy and tactics of creating a permanent vascular access, monitoring its dysfunction, pathophysiology of functioning of arteriovenous fistulas. Presented herein are unified approaches to diagnosis and treatment of thrombolytic and haemorrhagic complications associated with the access, as well as local infectious and non-infectious complications. Special attention is paid to indications for the operation and rational therapeutic decision-making.

Liposuction used to treat deep vascular accesses for hemodialysis

BACKGROUND

Oftentimes, obese dialysis patients develop a viable dialysis access but the access is too deep for cannulation and needs a superficialization procedure.

METHODS

We present our 14-patient cohort in whom we performed liposuction to superficialize viable but deep vascular accesses. Out of 14 patients, 12 had arteriovenous fistulas and 2 arteriovenous grafts. The primary end points were the ability to superficialize a completely unusable access and to remove the hemodialysis catheter (3patients), or to significantly extend the useful length of a deep access in which only a very short segment was used and to continue to use the access post-surgery without the need to place a dialysis catheter (11 patients).

RESULTS

The study goal was met in 13 out of 14 patients. In two of three patients, the catheters were removed and their access usable length was 14 and 13 cm, respectively. The accesses could be used immediately after liposuction in all patients in which this applied-11 patients. The usable access length increased from a mean of 5 to 12.7 cm. The access mean depth decreased from 10.8 mm pre-surgery to 7 mm post-surgery and 5.3 mm 4 weeks after surgery. The mean volume of fat removed was 43.8 cc. We had only one surgical complication: bleeding that was readily controlled with manual pressure. All patients were discharged to home the same day. Postoperative pain was mild.

CONCLUSION

Liposuction is effective, safe, and seems to be the least invasive technique of superficialization.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Technical note: An alternative method for AV access superficialization

INTRODUCTION

An arteriovenous fistulae for dialysis access is only functional if superficial enough for reliable cannulation. We describe a previously unreported technique to superficialize arteriovenous fistulae too deep for reliable cannulation.

METHOD

The path of the fistula is marked using ultrasound, and three to four transverse incisions are made along this path. The subcutaneous tissue is separated from the dermis over this entire area. The fistula is then accessed through transverse incisions and by dividing the overlying adipose tissue. The mobilized vein is then "trapped" directly under the dermis by closing the superficial fascia and adipose tissue beneath it and using this tissue to elevate the fistula. No anastomotic revisions are necessary, and moderate straightening can be performed.

RESULTS

We have performed this procedure on 20 patients with 100% technical success. One fistula had thrombosis within 8-10 weeks of the superficialization procedure and one patient refused access due to pain, but all other fistulas were successfully cannulated. Two patients were lost to follow-up, and one patient developed skin breakdown in the area of the flap which delayed cannulation. Our 3-month patency was 94.4% with a functional patency, defined as a clinically patent fistula successfully being used for hemodialysis, of 87.5%.

CONCLUSION

The technique described allows elevation of the vein to the level of the dermis without division and re-anastomosis or re-tunneling, through several small incisions maintaining virgin skin and normal contour for easier cannulation.

Patient selection, education, and cannulation of percutaneous arteriovenous fistulae: An ASDIN White Paper

End-stage kidney disease patients who are candidates for surgical arteriovenous fistula creation commonly experience obstacles to a functional surgical arteriovenous fistula, including protracted wait time for creation, poor maturation, and surgical arteriovenous fistula dysfunction that can result in significant patient morbidity. The recent approval of two endovascular devices designed to create a percutaneous arteriovenous fistula enables arteriovenous fistula creation to be placed in the hands of interventionalists, thereby increasing the number of arteriovenous fistula providers, reducing wait times, and allowing the patient to avoid surgery. Moreover, current studies demonstrate that patients with percutaneous arteriovenous fistula experience improved time to arteriovenous fistula maturation. Yet, in order to realize the potential advantages of percutaneous arteriovenous fistula creation within our hemodialysis patient population, it is critical to select appropriate patients, ensure adequate patient and dialysis unit education, and provide sufficient instruction in percutaneous arteriovenous fistula cannulation and monitoring. In this White Paper by the American Society of Diagnostic and Interventional Nephrology, experts in interventional nephrology, surgery, and interventional radiology convened and provide recommendations on the aforementioned elements that are fundamental to a functional percutaneous arteriovenous fistula.

UK renal transplant outcomes in low and high BMI recipients: the need for a national policy

INTRODUCTION

We assessed the effect of recipient body mass index (BMI) on the outcomes of renal transplantation and the management of obese patients with end-stage renal disease across the UK.

METHODS

We analyzed data of 25539 adult renal transplants (2007-2016) from the UK Transplant Registry. Patients were divided in BMI groups [underweight: < 18.5, normal: 18.5-24.9 (reference group), overweight: 25-29.9, class I obese: 30-34.9, class II/III obese: ≥ 35]. We also conducted a national survey of all UK renal transplant centers on the influence of BMI on decisions regarding management of renal transplant candidates.

RESULTS

BMI ≥ 25 was an independent risk factor for delayed graft function and primary non-function (p ≤ 0.001). Underweight (p = 0.001), class I obese (p = 0.017) and class II/III obese recipients (p < 0.001) had poorer graft survival, however, 5- and 10-year graft survival rates were good. Patient survival was shorter for underweight recipients (p < 0.001) and longer for overweight (p = 0.028) and class I obese recipients (p = 0.013). The national survey revealed significant variability among transplant centers in BMI threshold for listing patients on transplant waiting list and limited support with conservative or surgical procedures for weight control.

CONCLUSIONS

Obesity alone should not be a barrier for renal transplantation. A national strategy is required to give all patients equal chances in transplantation.

Lipectomy Technique as a Second-stage Procedure for Primarily Matured, Deep Outflow Vein in Obese Individuals

Prevalence of obesity is growing in the general population as well as among end-stage renal disease (ESRD) patients requiring dialysis. Obesity often leads to a situation when a mature outflow vein is located deeper than 6 mm and is difficult to cannulate. These obese patients usually require additional procedures to able to successfully cannulate the fistula. The available surgical options include: outflow vein elevation, liposuction, and lipectomy. We present a case of a 57-year-old obese female with ESRD and matured, deeply running, inadequate for cannulation arteriovenous fistula. We present a technique of lipectomy with wide resection of adipose tissue from superior and lateral surfaces of outflow vein. Postoperatively, the skin without the underlying adipose tissue collapses allowing easy cannulation of the long segment of outflow vein with two needles. Lipectomy of mature but deeply located outflow vein is a second-stage elective procedure. Wide resection of adipose tissue helps create easy to access cannulation zone in obese individuals.

Staged ultrasound-guided liposuction for hidden arteriovenous fistulas in obese patients

Abstract. Background: In obese patients with end stage renal disease, puncturing matured arteriovenous fistulas (AVF) that run deep under the skin surface may prove difficult. To achieve reliable puncturability, there are several surgical solutions. Superficialization with mobilization is common. With some newer options (lipectomy and liposuction) subcutaneous adipose tissue is surgically reduced. There are only a few authors who have published their experience with liposuction and we want to add our own results. Patients and methods: We report our experience with ultrasound-guided liposuction (USGL). We introduce liposuction cannulas via small incisions to reduce the subcutaneous adipose tissue overlying the planned cannulation zones under ultrasound control using tumescent anaesthesia till the prospective needle access segments become easily palpable. So far, we have used this technique for cephalic forearm and upper arm fistulas only. Furthermore, we review the relevant literature. Results: From February 2014 through November 2016, six patients were treated using USGL. Their body mass indices ranged from 30.8 to 53.8 kg/m2 (mean 37.6). The mean depths of the AVFs beneath the skin surface were 13.3 (8–20) mm before and 5.1 (3.5–6) mm after surgery. The mean time of the procedure was 15 minutes. There were no postoperative complications. In five patients, the AVFs could reliably be punctured after three weeks. One patient is not yet on dialysis. During the follow-up period of 24 (11–43) months, all six AVFs remained primarily patent. In the literature, we found nine reports on altogether 81 patients undergoing USGL. Almost all noteworthy complications occurred only after ultrasound-powered liquefaction of adipose tissue, which was only used by a single investigator. Conclusions: USGL is a method that can be learned easily, is minimally invasive, seems to be safe, and requires only short operation times.

Creating Arteriovenous Fistulas using Surgeon-performed Ultrasound

Purpose

An arteriovenous fistulas (AVF) is the preferred vascular access for hemodialysis and is associated with lower mortality, morbidity and cost when compared with grafts and particularly with central venous dialysis catheters. This study reviews a series of new patients where an autogenous access was constructed for each individual utilizing surgeon-performed ultrasound (SP-US).

Methods

Consecutive new patients referred for a permanent vascular access during an 11-year period were retrospectively reviewed. In addition to physical examination, each patient underwent SP-US evaluation for preoperative vessel mapping and post-operative evaluation for access maturation. SP-US was also used in the evaluation of access dysfunction in mature AVFs.

Results

We identified 1874 patients. Ages were 8-94 years (mean 60 years). Of these, 51% were female and 59% were diabetic; 33% had previous failed access operations. Follow-up was 3-127 months (mean 23 months). An autogenous access was constructed for each individual. No grafts were used. Direct AVFs were constructed in 1240 (66%) patients and 634 (34%) individuals required a transposition or translocation procedure. Primary and cumulative patency rates were 60.0% and 93.0% at 12 months and 47.3% and 90.2% at 24 months, respectively. AVF arterial inflow was most commonly supplied by the proximal radial artery (67%).

Conclusions

Creating a functional autogenous vascular access is possible for most patients. No grafts were used in this series of 1874 consecutive new patients. Important elements for success included SP-US evaluation, utilization of the many vascular access options available, establishing radial artery AVF inflow when feasible, and prompt intervention when indicated.