Obesity and thrombotic risk

Higher body mass index is associated with reinterventions and lower maturation rates after upper extremity arteriovenous access creation

OBJECTIVE

A patient's body mass index (BMI) can affect both perioperative and postoperative outcomes across all surgical specialties. Given that obesity and end-stage renal disease are growing in prevalence, we aimed to evaluate the association between BMI and outcomes of upper extremity arteriovenous (AV) access creation.

METHODS

A retrospective single-institution review was conducted for AV access creations from 2014 to 2018. Patient demographics, comorbidities, and AV access details were recorded. BMI groups were defined as normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (30-39.9 kg/m²), and morbidly obese (>40 kg/m²). Perioperative complications and long-term outcomes including access maturation (defined as access being used for hemodialysis or the surgeon's judgment that access was ready for use in patients not yet on hemodialysis), occlusion, and reintervention were evaluated.

RESULTS

A total of 611 upper extremity AV access creations were performed on patients who were normal weight (29.6%), overweight (31.3%), obese (29.6%), and morbidly obese (9.5%). Access type included brachiocephalic (43.2%), brachiobasilic (25.5%), and radiocephalic (14.2%) fistulas and AV grafts (14.2%). Median age was 60.9 years, and 59.6% were male. Univariable analysis showed no difference between BMI groups for perioperative steal, hematoma, home discharge, or 30-day primary patency. Freedom from reintervention at 2 years on Kaplan-Meier analysis differed by BMI (44.5% ± 4.6% normal weight, 29% ± 3.8% overweight, 39.8% ± 4.3% obese, 34.7% ± 8% morbidly obese; P = .041). There was no difference in 2-year freedom from new access creation or survival. AV access maturity within 180 days differed between BMI groups (74.3% normal weight, 66% overweight, 65.7% obese, 46.6% morbidly obese; P < .001). On multivariable analysis, failure to mature within 180 days was associated with overweight (odds ratio [OR], 1.93; 95% confidence interval [CI], 1.14-3.29; P = .002), obese (OR, 2.12; 95% CI, 1.19-3.47; P = .009), and morbidly obese (OR, 3.68; 95% CI, 1.85-7.3; P < .001) relative to normal weight BMI. AV access reintervention was associated with overweight (hazard ratio [HR], 1.83; 95% CI, 1.34-2.5), obese (HR, 1.56; 95% CI, 1.12-2.16), and morbidly obese (HR, 1.69; 95% CI, 1.1-2.58; P = .02) relative to normal weight BMI. BMI was not independently associated with long-term readmission or survival.

CONCLUSIONS

Obesity is associated with higher rates of AV access failure to mature and reintervention. Surgeons performing access creation on obese patients must consider this for planning and setting expectations. Weight loss assistance may need to be incorporated into treatment algorithms.