Arterial and Venous Anatomies of the Deep Inferior Epigastric Artery Perforator and Superficial Inferior Epigastric Flaps

Abstract

Sir: We have read with great interest the comments of Dr. Uraloğlu and colleagues on our recently published article, “Arterial and Venous Anatomies of the Deep Inferior Epigastric Artery Perforator and Superficial Inferior Epigastric Flaps.”1 We are very grateful to the authors for giving us the opportunity to further discuss our findings on these flaps using new imaging modalities, and would like to respond to each point in turn. The authors discuss our finding of absent perfusion deep to the Scarpa fascia in zone IV of the deep inferior epigastric perforator (DIEP) flap even if a medial row perforator is used, which is in accord with previous findings by Moon and Taylor,2 and ask whether skin vascularization and survival could be increased by fatty tissue trimming. The relative underperfusion of this region in our study despite maximal flap filling suggests that where zone IV is included in a DIEP flap, this part of the flap should be thinned to the Scarpa fascia. Although this region is a likely source of the fat necrosis seen clinically in certain cases, it is unlikely to cause vascular steal, and we would conclude that it is unlikely that trimming the fatty tissue in this region would increase the skin perfusion. The authors ask whether we found a correlation between the diameter of deep inferior epigastric artery perforators and area of flap perfusion. We investigated the diameters and deep inferior epigastric artery perforator vessel wall thickness histologically and found no significant differences in the diameters of the medial or lateral row perforators, or between perforators in the same row. All flaps investigated were based on the single largest perforator from either the medial or lateral row. We found that flap perfusion was dependent on the branching pattern of the perforator, and that a single medial row perforator with wide subcutaneous branching crossing the midline was capable of perfusing the entire flap. In contrast, a single lateral row perforator preferentially vascularized the ipsilateral hemiabdomen and rarely crossed the midline. Both medial and lateral row perforators were investigated under the same experimental conditions; thus, we would expect similar results clinically. We use the superficial inferior epigastric artery flap for breast reconstruction in selected cases where a DIEP flap is planned but where vessel diameter is found to be suitable to harvest a superficial inferior epigastric artery, to reduce donor-site morbidity.3 We aimed to determine the perfusion mechanism of the superficial inferior epigastric artery and its area of perfusion. We found that the superficial inferior epigastric artery perfused the flap as a lateral row perforator would, and that no perfusion was seen across the midline. We were not suggesting application of superficial inferior epigastric artery flaps together with DIEP flaps, but sought to elucidate the common mechanisms in perfusion of the lower abdominal integument. We are very grateful to the authors for their comments and hope that we have provided further clarity on the mechanisms of DIEP flap perfusion. DISCLOSURE Neither of the authors has a financial interest in the content of this communication or of the article it relates to. Michel Saint-Cyr, M.D. Mark Schaverien, M.R.C.S. Department of Plastic Surgery University of Texas Southwestern Medical Center Dallas, Texas