Large-to-Small End-to-Side Venous Anastomosis in Free Flap Transfer

Abstract Background Vessel size discrepancy is one of the major risk factors for anastomotic failure in free flap transfer. The situation becomes challenging for reconstructive microsurgeons when the recipient vein is much smaller than the flap vein. We investigated the feasibility of large-to-small end-to-side venous anastomosis for such cases. Materials and methods The subjects were 16 consecutive patients who underwent a free flap transfer for oncologic defects with a large-to-small end-to-side venous anastomosis. The larger flap vein was anastomosed to the side slit of the smaller recipient vein under an operating microscope. Surgical details and postoperative outcome were investigated retrospectively. Results An anterolateral thigh flap was used in five patients, a superficial inferior epigastric artery flap in four, a thoracodorsal artery perforator flap in three, and a latissimus dorsi musculocutaneous flap and a fibular osteocutaneous flap in two patients each. The internal mammary vein and the anterior tibial vein were most frequently used as a recipient vein (four patients each), followed by the deep inferior epigastric vein (three patients). The extent of vessel size discrepancy ranged from 1.3- to 3.3-fold, and the mean discrepancy was 1.9-fold. No anastomotic failure occurred postoperatively, and the flap survived in all patients. Conclusions Large-to-small end-to-side venous anastomosis can be a versatile option when only a small vein is available as a recipient vein. Internal mammary, deep inferior epigastric, and anterior tibial veins are good candidates for this technique.