Prevalence of complications of arteriovenous fistulas using doppler ultrasound among hemodialysis patients at two national referral hospitals in uganda

Abstract

Introduction: End-stage kidney disease (ESKD) is a rapidly increasing global health burden that often requires renal replacement therapy like hemodialysis. Hemodialysis is a life-saving procedure for patients with renal failure and for this procedure to be performed one needs access to the patient’s bloodstream. This could be through dialysis catheters placed at major veins, Arteriovenous graft (AVG) or Autologous arteriovenous fistula (AVF). Arteriovenous fistulae are the preferred form of vascular access for hemodialysis due to durability but complications such as thrombosis, aneurysms, stenosis and infection could occur resulting in fistula failure. In this study, we set out to determine the prevalence and associated factors of the aforementioned complications among patients undergoing hemodialysis using AVFs at Mulago and Kiruddu National Referral hospitals. Aim of the study: To determine the prevalence of complications of arteriovenous fistula surgery using color doppler and their associated risk factors. Methodology: This study was a cross-sectional analytic study that involved patients with AV fistulas undergoing hemodialysis at Mulago and Kiruddu National Referral Hospitals over a two-month period. We recruited a total of 63 patients and analyzed 60 who met the inclusion criteria by continuous sampling until the required sample size was complete. Ultrasound examination of the AV fistula was done with a Shantou Institute of ultrasonic instrument (SIUI) 5300 MODEL 2015; a linear (5-12 MHz) high frequency probe was used. The examinations were performed with the patient supine with the arm extended and the operator (principle investigator) at the patient’s side. The AV fistula site was scanned and measurements of depth of the fistula and diameter were taken as well as peak systolic velocity and resistive index at the fistula site, afferent artery and efferent vein. Results: We recruited 63 patients who were undergoing hemodialysis for end stage renal disease (ESRD) using arterio-venous fistulas at Kiruddu and Mulago National Referral hospitals. We excluded three patients, two of whom had polytetrafluoroethylene (PTFE) grafts at the A-V fistula site and one with a lower limb fistula and we analyzed 60 patients. The average age was 49.8 years, majority of the patients were males (44/60, 73.3%) and most patients had a normal body mass index (BMI) (34/60, 56.7%). The commonest comorbidities were hypertension noted in all the patients 60 (100%), while 22 (36.7%) had diabetes mellitus 13 (21.7%) had HIV and none of the patients had known peripheral vascular disease. 46.7% of our patients had complications with the most common early complication being limb edema 10 (10%) while aneurysm was the most common late complication 14 (23.3%). We found that there was no association between the patient’s comorbidities and the development of these complications. Conclusion: Most of the patients in low resource settings such as ours, once diagnosed with ESRD undergo hemodialysis for the rest of their lives thus making a functional AVF fistula essential to their survival. Doppler ultrasound studies are more available, done real time at bedside, are safe and can adequately provide a diagnosis compared to studies such as angiography. This would therefore enable early diagnosis and timely management of these complications. Recommendation We recommend scanning to confirm maturity of the fistula before use. Ultrasound scans should be made readily available for those patients with problems receiving dialysis such as poor blood pressure within the vessels used for the fistula as well as those who have complaints such as pain or swelling of their fistula.