Perforasomes of the DIEP Flap: Vascular Anatomy of the Lateral versus Medial Row Perforators and Clinical Implications

TLDR

The classic Hartrampf zones II and III of DIEP flap perfusion are reversed, with blood flowing ipsilaterally before crossing the midline. The study hypothesizes that perfusion zones and vascular anatomy differ markedly between lateral and medial row perforators and employs 3‑D/4‑D CT angiography to reassess these zones. The authors simulated 36 DIEP flaps (14 lateral, 22 medial), injected each perforator with contrast, performed dynamic CT scanning, and analyzed branching patterns and perfusion flow using TeraRecon software. Medial perforators exhibit larger vascular territories and greater Zone II perfusion, conforming to Hartrampf zones, whereas lateral perforators show greater Zone III perfusion, follow Holm theory with reversed zones, rarely cross the midline, and thus possess distinct stereotypical perfusion zones that influence flap design.

Abstract

Regarding the perfusion of a deep inferior epigastric perforator (DIEP) flap, the classic Hartrampf zones II and III were demonstrated by Holm et al. to be reversed using fluorescent perfusion techniques, implying that blood flow from the pedicle travels to the ipsilateral side before crossing the midline. The authors' hypothesis is that the zones of perfusion and the vascular anatomy differ greatly between lateral row and medial row perforators.Three-dimensional and four-dimensional computed tomographic angiography was utilized to reappraise the zones of vascularity. Thirty-six DIEP flaps were simulated for this study (14 lateral row perforators versus 22 medial row perforators). Individual perforators were injected with contrast and each flap was subjected to dynamic computed tomography scanning. Images were viewed using TeraRecon software, allowing analysis of branching patterns and perfusion flow.The mean vascular territory for a medial perforator DIEP flap injected with contrast was 296 cm, compared with 196 cm for a lateral perforator DIEP flap. Zone II perfusion was greater in a medial perforator compared with a lateral perforator. Zone III had greater perfusion in a lateral perforator compared with a medial perforator. The authors found that medial perforators conform to the Hartrampf zones of perfusion and lateral perforators follow the Holm theory of perfusion (zones II and III should be reversed for lateral perforator DIEP flaps). Injection of a lateral row-based perforator flap gave a vascular territory that rarely crossed the midline.Medial and lateral row perforators offer distinct and stereotypical zones of perfusion that have a significant effect on flap design and harvesting.