Venous congestion and blood flow in free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps

A series of 240 deep inferior epigastric perforator (DIEP) flaps and 271 fr ee transverse rectus abdominis myocutaneous (TRAM) flaps from two instituti ons was reviewed to determine the incidence of diffuse venous insufficiency that threatened flap survival and required a microvascular anastomosis to drain the superficial inferior epigastric vein. This problem occurred in fi ve DIEP flaps and did not occur in any of the free TRAM flaps. In each of t hese cases, the presence of a superficial inferior epigastric vein that was larger than usual was noted. It is therefore suggested that if an unusuall y large superficial inferior epigastric vein is noted when a DIEP flap is e levated, the vein should be preserved for possible use in flap salvage. Ana tomical studies with Microfil injections of the superficial venous system o f the DIEP or TRAM nap were also performed in 15 cadaver and 3 abdominoplas ty specimens to help determine why venous circulation (and flap survival) i n zone TV of the flaps is so variable. Large lateral branches crossing the midline were found in only 18 percent of cases, whereas 45 percent had indi rect connections through a deeper network of smaller veins and 36 percent h ad no demonstrable crossing branches at all. This absence of crossing branc hes in many patients may explain why survival of the zone TV portion of suc h flaps is so variable and unpredictable.