CORONADO, CALIF. – Intraoperative vessel assessment, not preoperative vein mapping, was more accurately associated with maturation and cumulative functional patency rates of arteriovenous fistulas, results from a 5-year, single-center retrospective study showed.
“The prevalence of chronic kidney disease has increased over the last 3 decades, and efforts by the Centers for Medicare & Medicaid Services and the National Kidney Foundation have sought to increase the use of fistulas,” Dr. Khanh P. Nguyen said at the annual meeting of the Western Vascular Society.
Dr. Khanh P. Nguyen
“Since 2003, the incidence and prevalence of fistulas have increased. More recently, even higher goals have been set. Arteriovenous fistulas are the preferred procedures due to higher patency rates, reduced rates of reintervention, and lower costs, compared with central venous catheters or grafts.”
Dr. Nguyen, formerly of Loma Linda (Calif.) Medical Center who is now a vascular surgery fellow at Oregon Health and Science University, noted that while many studies as well as the Society for Vascular Surgery have advocated the use of routine preoperative ultrasound in predicting the success of arteriovenous fistulas (AVFs), its use varies among vascular surgeons. “Given the additional costs and time of preoperative ultrasound, this study was undertaken to examine the use of this technique and compare it to intraoperative assessment,” she said.
The researchers examined all autologous AVFs created for patients with end-stage-renal disease at the Veterans Affairs Loma Linda Health System between February 2007 and July 2012. Preoperative ultrasound mapping of upper-extremity veins occurred, and patients were divided into two groups: those with veins less than 3 mm in size and those with veins 3 mm or greater in size. Subjective intraoperative evaluation was conducted by the operative surgeon, who rated the vein as either “good” or “poor” because of factors such as inadequate diameter, sclerosis, and calcification. Kaplan-Meier analysis was used to calculate maturation and patency rates.
Over the 5-year period, 387 fistulas were created in 361 patients. Of these, 198 had preoperative vein mapping; 36% were less than 3 mm in size, and 64% were 3 mm or greater in size.
By intraoperative assessment, 14% of patients were determined to have had poor vessels, and 86% were found to have good vessels. About half of the fistulas (51%) were created at the wrist. The average age of patients was 65 years, their mean body mass index was 28 kg/m2, and their mean time on dialysis was 84 years. The majority (97%) were male.
Among patients with preoperative veins less than 3 mm in size or 3 mm in size or greater, the maturation and overall failure rates were similar at 71% vs. 75% (P = .61) and 68% vs. 58% (P = .15). However, among patients with assessments of poor or good veins at the time of operation, the maturation and overall failure rates were 42% vs. 82% (P < .001) and 86% vs. 54% (P < .001).
Subgroup analysis revealed that patients with good intraoperative evaluation, regardless of preoperative ultrasound findings, had higher maturation rates. “Likewise, patients with good intraoperative assessment, regardless of preoperative ultrasound findings, had higher cumulative functional patency rates. Of note, no patient who had both poor preoperative ultrasound and intraoperative assessments had a functional fistula at the time of last follow-up.”
Dr. Nguyen and her associates concluded that intraoperative vessel assessment, and not preoperative ultrasound, was more accurately associated with maturation and cumulative functional patency rates. “Even in patients with inadequate preoperative ultrasound vein mapping, intraoperative assessment may still be warranted,” she said. “If both preoperative and intraoperative assessments conclude that vessels are inadequate, do not create an AVF at that site.”
Dr. Nguyen reported having no relevant financial disclosures.
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