[Relation of venous drainage and inadequate circulation in the rat pedicled TRAM flap model]

To evaluate the circulatory characteristics of the TRAM flap because the vascular supply to lateral portion of the conventional TRAM (zone 4) occasionally may become compromised resulting in necrosis of fat tissue or requiring segmental excision of the poor perfused tissue.

In this study, we designed a rat pedicled TRAM flap model with either inadequate arterial or venous circulation. The skin paddle was photographed and the survival areas were measured on the tenth postoperative day.

The results showed that the group with poor arterial inflow of the flap, which resulted from ligation of the superior deep epigastric artery, exhibited skin necrosis in zone 1 and 2. Venous stasis due to selective ligation of the venous pedicle resulted in necroses of a major area in the lateral part of the flap, especially in zone 4. However, venous stasis may be alleviated by an additional cutaneous venous return system.

Our results demonstrated that conventional rat TRAM flap with poor arterial inflow differs from that with venous stasis in terms of manifestations and extent of inadequate circulation. Necrosis of the lateral portion of human TRAM flaps may therefore be attributed to problems of venous stasis. Such problems might then be ameliorated by creating an additional cutaneous venous return system.