A Prospective Evaluation of U-clips for Arterial Microvascular Anastomoses

Abstract

The nitinol U-clip (Medtronic, Inc.; Minneapolis, MN, USA) is similar to conventional suturing but eliminates knot tying, thereby decreasing ischemia time. This study is the first clinical trial of this new technology for arterial microsurgical anastomoses in free tissue transfer. We performed a prospective clinical trial of nitinol U-clips for 25 consecutive arterial microsurgical anastomoses. Standard microsurgical techniques and instruments were used, and the primary outcome was free flap survival. The secondary outcomes were ischemia time, operating room (OR) time, number of clips used, and recipient/donor-site complications. Significant recipient/donor-site complications were defined as those requiring re-operation. Descriptive statistics were used and minimum follow-up was 3 months. All anastomoses were successful (25/25). The most common etiology of the defect was cancer resection (92%), and 44% of the recipient vessels had been irradiated prior to surgery. Mean ischemia time was 29 minutes (range 12 to 54 minutes), and mean OR time was 7.4 hours. On average, seven U-clips were used per arterial anastomosis (range 5 to 12). At 3-month follow-up, there was a 100% flap survival rate with no significant recipient-site or donor-site complications. This study suggests that the nitinol U-clip provides rapid, reproducible microvascular arterial anastomoses.