Preoperative point-of-care ultrasound and its impact on arteriovenous fistula maturation outcomes

Objective: Duplex ultrasound as a preoperative assessment tool in the clinic may help identify anatomic factors predictive of fistula maturation. Preoperative point-of-care ultrasound (POCUS) offers surgeons an alternative to routine formal vein mapping as it can be performed by the operator during the initial clinic visit. We sought to determine the impact of POCUS as an adjunct to physical examination on arteriovenous fistula maturation. Methods: All consecutive patients undergoing first-time dialysis access creation from December 2007 to December 2014 were retrospectively reviewed. Surgeons who routinely use POCUS to assess preoperative maximal vein diameter and quality were compared with surgeons who relied only on physical examination. All access and patency definitions were in accordance with the Society for Vascular Surgery's reporting standards. The effects of POCUS on fistula maturation rate and fistula abandonment were analyzed using logistic regression, controlling for comorbidities of the patient, anticoagulant use, and location of fistula. Results: A total of 316 patients were included in the study; 250 patients were assessed exclusively with physical examination, and 66 patients underwent preoperative ultrasound examination by the vascular surgeon in the clinic. The primary failure rate in the ultrasound group was 18% compared with 47% (P < .001) in the group of patients who did not undergo ultrasound examination. In patients without preoperative ultrasound, there were higher rates of new access creation (31% vs 9%; P < .001) and fistula abandonment (66% vs 39%; P < .001). Multivariable analysis demonstrated that fistulas created without preoperative ultrasound were associated with a 3.56 greater risk of failure (95% confidence interval, 1.67-7.59; P = .001) compared with fistulas in the POCUS group. Similarly, the rate of fistula abandonment was 2.63 times higher (95% confidence interval, 1.38-5.05; P = .003) when ultrasound was not used preoperatively. Time to functional fistula maturation was better in the ultrasound group (P < .001). At 1 year, 12% of fistulas in the ultrasound group and 32% in the clinical examination group had yet to be cannulated. Secondary patency at 1 year was better in the POCUS group at 73% compared with 59% in the group with no preoperative ultrasound (P = .01). Conclusions: POCUS as an adjunct to physical examination for dialysis access patients leads to decreased rates of primary failure, new access creation, and fistula abandonment compared with patients who undergo only physical examination. Ultrasound examination improved times to functional fistula maturation and secondary patency. Further studies are required to compare POCUS with formal preoperative vein mapping for arteriovenous fistula planning.