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Large‐to‐small end‐to‐side anastomosis to the internal mammary vein: A solution to vessel size discrepancy

The internal mammary vein is commonly used as a recipient vein in microvascular esophageal reconstruction and autologous breast reconstruction. Size discrepancy frequently becomes a problem because the internal mammary vein is usually narrower than flap veins. Although most surgeons prefer to perform end-to-end anastomosis with a venous coupler, we believe conversion to endto-side anastomosis to the internal mammary vein is a possible solution for vessel size discrepancy. We report on a 65-year-old man with esophageal cancer who underwent subtotal esophagectomy and immediate reconstruction with a supercharged jejunal pull-up because of a history of gastrectomy. The jejunum was subcutaneously pulled up to the cervical region on the basis of the fourth jejunal vessels, and the second jejunal vessels were used for supercharging. As recipient vessels, the right internal mammary vessels were dissected by removing the second costal cartilage; however, the right internal mammary vein was much smaller than the second jejunal vein (approximately 1.2 mm versus 4.0 mm in external diameter). We, therefore, performed end-to-side anastomosis between the second jejunal vein and the internal mammary vein (Fig. 1). The esophagojejunal anastomosis was performed in an end-to-end fashion. The postoperative course was uneventful, and the monitoring segment of the jejunal flap remained pink throughout. To the best of our knowledge, no article described end-to-side anastomosis to the internal mammary vein, perhaps out of concern that a smaller recipient vein cannot accept the flow from a larger vessel. We believe that this concern is misplaced because our previous studies in a rat free-flap model have demonstrated the feasibility of large-to-small end-to-side venous anastomosis. End-toend anastomosis has a high risk of failure when a significant size discrepancy is present; in such cases, the advantages of end-to-side anastomosis become clear. When the internal mammary vein is found during preparation to be extremely small, we recommend not dividing the vein before flap harvest and leaving end-to-side anastomosis as an option.