Free flap monitoring using an implantable anastomotic venous flow coupler: Analysis of 119 consecutive abdominal-based free flaps for breast reconstruction.

PURPOSE

The purpose of this study is to evaluate the use of the venous anastomotic Flow Coupler in monitoring free flaps used for breast reconstruction in a consecutive series of patients.

METHODS

Retrospective data were collected on patients undergoing free flap breast reconstruction from May 2012 to March 2014. The venous anastomotic Flow Coupler was used in the first 85 flaps and a non-flow Coupler with clinical and external Doppler monitoring alone in the subsequent 34 flaps. Data collected included patient age, BMI, prior radiation, flap type, intra- and postoperative Flow Coupler events, along with rates of flap take back, salvage, and failure. Proportion data were compiled and statistically analyzed.

RESULTS

One hundred nineteen consecutive abdominal based breast reconstruction free flaps were performed. The overall flap failure rate was 4.2% (4.7% Flow Coupler; 2.9% in non-flow Coupler; P = 1.0). The Flow Coupler demonstrated 100% sensitivity in the intra- and postoperative settings. A positive predictive value of 36% was noted intraoperatively which was significantly higher compared to the non-flow Coupler group (P = 0.015). Vessel thrombosis occurred in 17.6% of Flow Coupler flaps, which was significantly higher when compared to the non-flow Coupler (2.9%; P = 0.038).

CONCLUSIONS

The Flow Coupler is a sensitive method to confirm patency of a microsurgical anastomosis. However, there is a high false positive rate in both the intraoperative and postoperative settings resulting in frequent intraoperative maneuvers to amend the cause of signal loss. Additionally, the Flow Coupler resulted in significantly more vascular thrombotic events when compared to the non-flow Coupler.