Obesity-related decrease in intraoperative blood flow is associated with maturation failure of radiocephalic arteriovenous fistula

Objective: Successful arteriovenous fistula (AVF) maturation is often challenging in obese patients. Optimal initial intraoperative blood flow (IOBF) is essential for adequate AVF maturation. This study was conducted to elucidate the effect of obesity on IOBF and radiocephalic AVF maturation. Methods: Patients with a newly created radiocephalic AVF were included (N = 252). Obesity was defined as a baseline body mass index (BMI) >= 25 kg/m(2), and primary maturation failure was defined as failure to use the AVF successfully by 3 months after its creation. IOBF was measured immediately after construction of the AVF with a VeriQ system (MediStim, Oslo, Norway). Results: The mean BMI was 24.1 +/- 3.9 kg/m(2), and the prevalence of obesity was 31.3%. Particularly, 8.3% (21 patients) had a BMI >= 30 kg/m(2). Primary maturation failure occurred in 100 patients (39.7%), and an IOBF <190 mL/min was closely associated with the risk of maturation failure (relative risk, 3.05; 95% confidence interval, 1.52-6.11). Compared with nonobese patients, obese subjects had a significantly higher prevalence of diabetes and elevated high-sensitivity C-reactive protein levels, whereas diameters of vessels were similar. When the patients were further divided into three groups as BMI <25, 25 to 29.9, and >= 30 kg/m(2), patients in the higher BMI group showed significantly lower IOBF and higher maturation failure rate. According to multivariate analysis, the statistically significant variables that determined maturation failure were obesity, previous vascular disease, increased high-sensitivity C-reactive protein levels, and IOBF <190 mL/min. Conclusions: Obese patients had a significantly lower IOBF, and both obesity and low IOBF contributed to the primary maturation failure of AVF. Obesity-associated inflammation and atherosclerosis might play roles in this association.