Venous Congestion and Blood Flow in Free Transverse Rectus Abdominis Myocutaneous and Deep Inferior Epigastric Perforator Flaps

TLDR

The authors recommend preserving an unusually large superficial inferior epigastric vein during DIEP flap elevation for potential flap salvage. They reviewed 511 DIEP and TRAM flaps to assess diffuse venous insufficiency and performed Microfil injections in 15 cadavers and 3 abdominoplasty specimens to map superficial venous anatomy and explain zone IV variability. Venous insufficiency threatened five DIEP flaps but none of the TRAM flaps, with all affected cases showing an enlarged superficial vein; anatomical analysis revealed that only 18 % had lateral branch crossings, 45 % had indirect deeper connections, and 36 % lacked crossings, accounting for unpredictable zone IV survival.

Abstract

A series of 240 deep inferior epigastric perforator (DIEP) flaps and 271 free transverse rectus abdominis myocutaneous (TRAM) flaps from two institutions 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 five DIEP flaps and did not occur in any of the free TRAM flaps. In each of these cases, the presence of a superficial inferior epigastric vein that was larger than usual was noted. It is therefore suggested that if an unusually large superficial inferior epigastric vein is noted when a DIEP flap is elevated, the vein should be preserved for possible use in flap salvage. Anatomical studies with Microfil injections of the superficial venous system of the DIEP or TRAM flap were also performed in 15 cadaver and 3 abdominoplasty specimens to help determine why venous circulation (and flap survival) in zone IV of the flaps is so variable. Large lateral branches crossing the midline were found in only 18 percent of cases, whereas 45 percent had indirect connections through a deeper network of smaller veins and 36 percent had no demonstrable crossing branches at all. This absence of crossing branches in many patients may explain why survival of the zone IV portion of such flaps is so variable and unpredictable.