Rezoning Free Muscle-Sparing Transverse Rectus Abdominis Myocutaneous Flaps Based on Perforasome Groupings and a New Understanding of the Vascular Architecture of the Deep Inferior Epigastric Artery-Based Flaps

Abstract

Background: We compare the vascular territory of free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps, deep inferior epigastric perforator (DIEP) flaps, and crossover anastomosis (CA) flaps using intraoperative ex vivo angiography. We also use ex vivo angiography to analyze the vascular architecture of the MS-TRAM flap.

Methods: Our study includes 84 lower abdominal free flaps: MS-TRAM, DIEP-1 (1 perforator), DIEP-2 (2 perforators), and CA. We compare the arterial perfusion area and vascular territory pattern in each group. We also analyze the vascular architecture in MS-TRAM flaps and determine the number and location of their dominant perforators and the direction of the axial arteries connecting them.

Results: The CA's arterial perfusion area is the largest, and the DIEP-1's, the smallest of our groups; there is no statistically significant difference between MS-TRAM and DIEP-2. In all groups, average arterial perfusion area in the vascular pedicle's ipsilateral side is larger than in its contralateral side. The MS-TRAM and DIEP-2 flaps have homologous perfusion patterns and the same arterial perfusion areas. The DIEP-1 perfusion pattern varies with perforator location. Ex vivo angiograms show the MS-TRAM flap's axial arteries heading laterally to be larger and longer than those heading medially.

Conclusions: Two dominant perforators are preferable in DIEP flap breast reconstruction. Lateral perforators play a more important role in flap perfusion than do medial ones. Crossover anastomosis is an effective technology for increasing arterial perfusion areas. Our rezoning shows which areas are better for surgery and which have a high risk of complications-valuable information for a surgeon designing a flap for breast reconstruction.