End-to-end versus end-to-side venous microanastomoses in head and neck reconstruction.

Venous thrombosis (VT) is the primary reason for microvascular free flaps (MFFs) failure. Different series have addressed the influence of venous anastomosis, end-to-end (ETE) vs. end-to-side (ETS), on this issue in head and neck (HN) microsurgery, but a consensus about the optimal technique to be adopted is still lacking. The aim of this study is to prospectively compare the venous complication rates of ETE and ETS techniques in 422 homogeneously treated patients who underwent MFF for HN oncologic defects between 2000 and 2012 at our Institution. Patients were divided into two groups: Group A (n = 269 patients) receiving an ETE and Group B (n = 153) an ETS venous anastomosis. The choice between the type of venous anastomosis was based on the several variables: availability of adequate caliber recipient veins in the neck, length and caliber of the donor vein, geometry and orientation of the vascular pedicle, and possibility to create a tensionless anastomosis. An ETE anastomosis was always preferred when feasible, while an ETS (performed on the internal jugular vein) was reserved to cases in which the abovementioned considerations contraindicated an ETE. Overall, the MFF failure rate was 3 %. Among the 13 failures, five had VT (1.1 %): three had received an ETE, and two an ETS. Venous anastomosis re-exploration and failure rates of the two groups were compared by the Chi-squared test showing no statistically significant differences. In conclusion, our data show how ETS venous anastomosis is a safe alternative to ETE whenever the latter cannot be properly accomplished for the previously mentioned contraindications.