Dynamic blood flow to the retrograde limb of the internal mammary vein in breast reconstruction with free flap

Background: In free flap breast reconstruction, the retrograde limb of the internal mammary vein (IMV) is occasionally used as a second recipient vein. In this study, we evaluated the dynamic blood flow to the retrograde limb of the IMV (retrograde IMV) at the anastomosed site via indocyanine green (ICG) angiography. Methods: In 40 patients undergoing free flap breast reconstruction, we evaluated the dynamic blood flow as “stain(+)” if a stain by ICG was observed and, “flow(+)” if a smooth blood flow was recognized. Results: Based on the ICG angiography, “stain(+)” was observed in all cases, but “flow(+)” was detected in only 72.5% of the cases. There was no severe complication. Conclusion: This study shows that thrombosis is prone to occur in the second recipient vein in the 27.5% of the cases with no smooth flow, and therefore, the retrograde IMV may not function as a back-up in these cases.