PERFUSION OF THE DIEP FLAPS: A SYSTEMATIC REVIEW WITH META-ANALYSIS

Purpose: Perfusion zones of the deep inferior epigastric perforator (DIEP) flap aid surgeons in estimating approximate tissue territory with reliable perfusion. Since the Hartrampf perfusion zone was developed, it has been modified continuously; however controversies remain regarding whether the recent perfusion models can satisfy current anatomical and clinical evidence. We conducted a comprehensive review of previous studies to synthesize relevant knowledge and critically reappraise current perfusion models. Methods: All anatomical and clinical studies that investigated perfusion of DIEP flaps were searched, yielding 21 studies suitable for review. A meta-analysis was conducted when sufficient data were provided. Results: The perforators had unpredictable subcutaneous courses and were preferentially directed laterally. The medial and lateral perforators showed different characteristics in terms of branching pattern, orientation, and linking vessels between them. Ex-vivo perfusion findings suggested that medial perforators favored Hartrampf zone II rather than zone III and perfused the entire abdomen frequently, whereas the lateral perforators favored zone III and their perfusion territories were limited primarily to the hemi-abdomen. In the meta-analysis based on the clinical perfusion studies, zone III had significantly higher perfusion than zone II (P = 0.04) and these tendencies remained in both medial and lateral perforator-based flaps. Conclusions: Considerable discrepancies were found between findings of ex-vivo and clinical perfusion studies. A thorough review of existing knowledge based on the perforasome concept explained these discrepancies satisfactorily and revealed unsolved issues of the current perfusion models. Flap perfusion clearly varies widely individually; however, this review will help with surgical planning and decision making. (C) 2016 Wiley Periodicals, Inc.