Retrospective analysis of arteriovenous fistula patency and failure in patients on dialysis for end-stage kidney disease in the Gaza strip

Background

The preservation of patent, well-functioning arteriovenous fistulas is one of the most difficult clinical problems in the long-term management of patients undergoing renal dialysis. This study aimed to define the patency and failure rates of fistulas in patients with end-stage kidney disease on dialysis and to examine how fistula failure is managed.

Methods

Data regarding disease history and long-term patency and failure of hemodialysis arteriovenous fistulas were collected from patients and patients' charts in five dialysis centres in the Gaza strip, including a specialised centre for paediatric dialysis, from May, 2017, to October, 2017, using a specifically designed data collection sheet. Informed written consent was obtained from participants upon enrolment.

Findings

Data were collected from 606 patients with end-stage kidney disease on dialysis. The mean age was 50·3 (SD 18·6) years and 56% (339 out of 606) were males. The mean age at diagnosis was 45 (19·9) years and at first fistula creation was 46·2 (19·2) years. Hypertension was the most common cause of end-stage kidney disease (34·7%; 210 of 606), followed by diabetes mellitus (26%; 158), and obstructive uropathy (11·6%; 70). Failure of the first fistula was reported for 36% (97 of 267) of females and 31% (105 of 339) of males. The failure rate at 1 month was 21% (43 of 202) for first fistulas and 13% (six of 45) for second fistulas. Hypertension was reported for 77% (156 of 202) of patients who encountered failure. Of first fistulas, failure was reported for 61% (21 of 34) of right distal, 39% (52 of 133) of left distal, 37% (37 of 101) of right cubital, and 31% (91 of 201) of left cubital fistulas, indicating that the site of placement of the first arteriovenous fistula might have had a role in determining failure. The mean time until fistula failure after creation was 0·8 years (SD 2·0, range 0–13) for first fistulas and 0·1 years (0·79, 0–8) for second fistulas. Most fistulas were created as direct arteriovenous fistula anastomoses. Synthetic grafts were used in three cases for first fistulas and in eight cases for second fistulas. The failure rate for synthetic graft fistulas was higher than for direct anastomosis, and the failure rates were 60% (two of three) and 62% (five of eight) for first and second synthetic graft fistulas, respectively. The management of fistula failure involved creating a new fistula in 85·6% (173 of 202) of first fistulas and 49% (22 of 45) of second fistulas. Of the 606 patients, 48 were paediatric patients younger than 18 years, with a mean age of 13 (3·6) years; two-thirds (60·4%, 29 of 48) of these patients were male. Their mean age at diagnosis was 7 years (SD 5·4) and the most prevalent aetiologies were congenital (40%; 20 of 48), obstructive uropathy (21%; ten), and glomerulonephritis (12%; six). Half of these patients (24 of 48) were on dialysis via a central line and all others had arteriovenous fistulas for dialysis. Proximal sites of the right and left upper forearms were preferred over distal sites for the first fistula in most cases, failure was reported in a third (16 of 48) of cases, and the mean duration of fistula patency before failure was 1 year (range 0–8 years). Of the patients who encountered fistula failure, 12 had direct anastomosis fistulas with the right cubital fossa as the preferred site. In five of these cases, failure of the second fistulas was encountered within 3 years.

Interpretation

Hypertension was the major cause of end-stage kidney disease, and this necessitates the proper recognition and management of hypertension, especially among middle-aged people (35–60 years). Female sex, hypertension, distal (versus proximal) placement of fistulas, and operations outside of Ministry of Health hospitals were found to be risk factors for fistula failure. The high failure rates at 1 month are likely to be due to technical issues relating to surgery, as fistulas are not used for dialysis before 1 month. To improve patency, preference should be given to direct anastomosis arteriovenous fistulas rather than synthetic grafts.

Funding

None.