Venous coupler size in autologous breast reconstruction - Does it matter?

Background Autologous microvascular breast reconstruction is an increasingly common procedure. While arterial anastomoses are traditionally being hand-sewn, venous anastomoses are often completed with a coupler device. The largest coupler size possible should be used, as determined by the smaller of either the donor or recipient vein. While its efficacy has been shown using 3.0-mm size and greater couplers, little is known about the consequences of using coupler sizes less than or equal to 2.5 mm. Methods: A retrospective chart review of patients undergoing autologous breast reconstruction was conducted at NYU Medical Center between November 2007 and November 2011. Flaps were divided into cohorts based on coupler size used: 2.0 mm, 2.5 mm, and 3.0 mm. Outcomes included incidence of arterial or venous insufficiency, hematoma, fat necrosis, partial flap loss, full flap loss, and need for future fat grafting. Results: One-hundred ninety-seven patients underwent 392 flaps during the study period. Patients were similar in age, type of flap, smoking status, and radiation history. Coupler size less than or equal to 2.0 mm was found to be a significant risk factor for venous insufficiency (P = 0.038), as well as for development of fat necrosis (P = 0.041) and future need for fat grafting (P = 0.050). In multivariate analysis, body mass index was found to be an independent risk factor for skin flap necrosis (P = 0.010) and full flap loss (P = 0.035). Conclusions: Complications were significantly increased in patients where couplers of 2.0 mm or less were used, therefore to be avoided whenever possible. When needed, more aggressive vessel exposure through rib harvest, the use of thoracodorsal vessels or hand-sewing the anastomosis should be considered in cases of internal mammary vein caliber of 2.0 mm or less. Clinical Question Therapeutic Level of Evidence Level III.