Annals of African Medicine

ORIGINAL ARTICLE
Year
: 2013  |  Volume : 12  |  Issue : 2  |  Page : 127--130

Outcome and complications of permanent hemodialysis vascular access in Nigerians: A single centre experience


Sani U Alhassan1, B Adamu2, A Abdu1, SA Aji2,  
1 Department of Surgery, Bayero University/Aminu Kano Teaching Hospital, PMB 3452, Kano, Nigeria
2 Department of Medicine, Bayero University/Aminu Kano Teaching Hospital, PMB 3452, Kano, Nigeria

Correspondence Address:
Sani U Alhassan
Department of Surgery, Aminu Kano Teaching Hospital, Kano
Nigeria

Abstract

Background: It is widely accepted that autogenous arteriovenous fistula (AVF) carries less morbidity and mortality compared to all other forms of vascular accesses in maintenance hemodialysis patients. There is paucity of data on vascular access from sub-Saharan Africa. The aim of this study was to assess the outcome and complications of permanent vascular access in our center. Materials and Methods: The study is a prospective, hospital-based, longitudinal study. All consecutive patients on maintenance hemodialysis in Aminu Kano Teaching Hospital who were referred to the surgical unit of for creation of permanent hemodialysis vascular access were included in the study. The patient«SQ»s clinical and demographic data were documented. Data about vascular access types, outcomes, and complications were obtained over a 1-year period from the time of vascular access creation. Results: One hundred and seventy four patients were operated upon between January 2008 and December 2010 with a mean age of 46.4 years (range 18-76 years) and a male to female ratio of 1.5:1. Brescio--Cimino fistula was performed in 110 (63.2%) patients, brachiocephalic (Kauffmann) fistula in 51(29.3%), and synthetic graft in 1 (0.6%) patients respectively. Ten patients (5.7%) had brachio-brachial transposition arteriovenous fistula and 2 patients (1.1%) had transposition graft using harvested long saphenous vein. One-year patency rate was 63.2%. Complications encountered include AVF failure in 47(27.3%), steal syndrome in 2(1.1%), distal venous insufficiency in 2(1.1%), and false aneurysm in 6(3.5%) patients. Conclusion: The outcome of permanent vascular access is favorable in our patient population with a one-year patency rate of 63.2%. The first choice of vascular access in our maintenance dialysis population should be AVF.



How to cite this article:
Alhassan SU, Adamu B, Abdu A, Aji S A. Outcome and complications of permanent hemodialysis vascular access in Nigerians: A single centre experience.Ann Afr Med 2013;12:127-130


How to cite this URL:
Alhassan SU, Adamu B, Abdu A, Aji S A. Outcome and complications of permanent hemodialysis vascular access in Nigerians: A single centre experience. Ann Afr Med [serial online] 2013 [cited 2021 Jun 19 ];12:127-130
Available from: https://www.annalsafrmed.org/text.asp?2013/12/2/127/112410


Full Text

 Introduction



End-stage renal disease (ESRD) is increasing worldwide and is now considered a global pandemic. Maintenance hemodialysis, one of the treatment options for ESRD, requires stable and repetitive access to intravascular compartment in order to deliver high rate of blood flow to extracorporeal haemodialysis circuits. It is widely accepted that autogenous arteriovenous fistula (AVF) carries less morbidity and mortality comparative to all other forms of vascular accesses. [1] There is paucity of data on vascular access from sub-Saharan Africa.

The aim of this study was to assess the outcome and complications of permanent vascular access in our center.

 Materials and Methods



This is a prospective, hospital-based, longitudinal study in which all patients on maintenance hemodialysis in Aminu Kano Teaching Hospital who were referred to the surgical unit for permanent vascular access creation were recruited. We excluded patients who were referred for permanent vascular access from other hemodialysis centers. Ethical clearance and informed consent from all patients were obtained. Vascular assessment was done manually to estimate venous and arterial sizes; Allen's test and assessment for venous thrombosis from previous vein canulation were performed by palpation. An elastic band was used to distend the veins at the arm level for antecubital fossa fistulae and at the wrist level for Brescio-Cimino fistula. All surgeries were carried out by the same surgeon. Radio-cephalic and brachio-cephalic fistula creation and transposition and polytetrafluoroethylene (PTFE) grafts were performed preferentially on the nondominant arm. We excluded from surgery all patients who had bilateral thrombosed cephalic veins at the wrist and antecubital fossa deemed unsuitable for successful AVF creation. The operative technique involved the use of magnifying loop (×2 Karl Zeiss) and 6/0 prolene (Ethicon) stay sutures to splay the incised arterial walls. All anastomoses were done end-to side (venous end to arterial side). Immediate assessment of flow for the presence or absence of thrills or pulsations at the operative site and proximally was done and this was repeated at 2 weeks, 4 weeks, 6 weeks, 8 weeks and at 12 months. Vascular accesses with good thrills/pulsations that were considered clinically mature were subjected to needling for hemodialysis at a mean time of 4.6 weeks post-op. The study endpoints were vascular access patency at 1 year or vascular access failure. Patients who did not have vascular access failure but could not complete 1-year follow-up due to other events (death, referral to another center, transplant or loss to follow-up) were censored as at the last follow-up date.

The collated data were analyzed using SPSS 15 statistical software. Continuous variables were presented as means ± SD while categorical variables were presented as percentages.

Fistula patency at the end of the study was analyzed using the Kaplan-Meier survival curve.

 Results



One hundred and seventy four patients were operated upon between January 2008 to December 2010 with a mean age of 46.4 years (range 18-76 years) and a male to female ratio of 1.5:1. All the patients were newly enrolled ESRD patients on maintenance hemodialysis except two who were predialysis. Patients from middle class and higher socio-economic group constitute 78% (135) of AVFs performed; the remaining 39 patients (22.4%) were from a low-income group. Brescio-Cimino fistula was performed in 110 (63.2%) patients, brachiocephalic (Kauffmann) fistula in 51 (29.3%) patients and synthetic graft in 1 (0.6%) patient [Table 1]. Ten patients (5.7%) had brachio-brachial transposition arteriovenous fistula and 2 patients (1.1%) had transposition graft using harvested long saphenous vein. Loop anastomosis was performed in 33 (18.9%) and ante-grade anastomosis in 137 (78.7%) patients. The external diameters of the arteries and veins (distended with heparinised saline) were measured with graduated caliper at operation and ranged 1.8-6 mm in diameter (mean 3.3 mm ± 0.9 SD and 2.45 ± 0.6 SD) respectively. Six patients (3.4%) had attempted fistula creation but either abandoned on exposing the vein (4) due intraoperative endoluminal fibrosis or never worked [2] postoperatively. The fistulae matured (as assessed by first successful needling for hemodialysis) over a period of 2-8 weeks (mean ± SD of 4.4 ± 1.6 weeks). The 1-year AVF patency rate was 63.2% (110 patients) and is presented in [Figure 1] as a Kaplan-Meier survival curve. Eleven patients died before completing 1-year follow-up, five were lost to follow-up, and one patient had kidney transplant before completing 1-year follow-up. Complications encountered include AVF failure in 47 (27.3%) patients, false aneurysm in 6 (3.5%) [Figure 2] patients, steal syndrome 2 (1.1%), and distal venous insufficiency in 2 (1.1%) patients [Table 2].{Figure 1}{Figure 2}{Table 1}{Table 2}

 Discussion



Vascular access procedures and their complications are major cause of morbidity, hospitalization and cost for patients receiving long-term hemodialysis, [3] yet it is vital to this form of renal replacement therapy.

According to the National Kidney Foundation's Dialysis Outcomes Quality Initiative (DOQI), autogenous arteriovenous fistulas (AVFs) provide patients with the best chance for prolonged, uninterrupted hemodialysis access, yet majority of CRF patients do not have this permanent vascular access at the start of dialysis even in the USA. [4],[5] The DOQI Clinical Practice Guidelines for Vascular Access recommend that primary arteriovenous fistulas should be constructed in at least 50% of all renal failure patients in the USA who elect to have hemodialysis as the initial RRT but only about 30% get AVF as dialysis access. In Nigeria, the figures are worse. Ekpe et al., reported only 5% of their patients on dialysis having permanent vascular access. [6] Studies from two other centers in Nigeria also reported temporary vascular access as common in the dialysis population. [7],[8]

There is paucity of data on autogenous fistula created in the sub-Saharan Africa perhaps due to inadequate manpower in vascular surgery on one hand, and poverty on the other hand.

Demographic factors that are known to be associated with delayed fistula maturation due to small vessels are advanced age, female gender, diabetes mellitus, African race, and obesity. All these factors are associated with small vessels and poor flow. [5],[9],[10]

A meta-analysis of 38 studies has shown that more than 15% of all radio-cephalic arteriovenous fistulas fail in the early postoperative period. [11]

The failure rate of 35.1% at 1 year in our study is likely multifactorial. Potential contributing factors include destruction of veins by venopuncture before fistula creation, poor technique in the control of postdialysis fistula bleeding site, inadequate information available to patients on care of AVF, and lack of facilities for secondary patency procedures.

Radiocephalic (RC) fistula patency was limited to young patients as no patient in this study over the age of 40 years had a patent RC fistula at the end of the study. This may be explained by the presence of atherosclerotic arteries leading to poor flow. The superior performance characteristics of the upper arm fistulae were overshadowed by the dreaded complication of steal syndrome yet they should still be preferred in native Africans especially those over the age of 40 years, because of longer term patency observed in these age groups in this study.

Only one patient had synthetic graft as permanent vascular access in this study, which failed after 6 months on dialysis. Synthetic grafts are particularly useful in patients with poor vessel quality, multiple punctured and thrombosed vessels or following a resolved complication of steal syndrome with hyper-dynamic circulation.

The main drawback of this study is that it is single surgeon dependent, creating potential bias on the chosen operative techniques. Other limitations include the lack of ultrasound assessment pre- and post-op, as well as the fact that comorbidities and their effect of vascular access outcome were not studied.

 Conclusion



The outcome of permanent vascular access is favorable in our patient population with a 1-year patency rate of 63.2%. Arteriovenous fistula should be the first choice of vascular access in our maintenance dialysis population.

 Acknowledgment



Habibu Ismail of Main Theatre Aminu Kano Teaching Hospital for facilitating these operations.

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