A Classification System for Partial and Complete DIEP Flap Necrosis Based on a Review of 17,096 DIEP Flaps in 693 Articles Including Analysis of 152 Total Flap Failures

BACKGROUND: In a comprehensive review of 17,096 deep inferior epigastric perforator (DIEP) flaps in 693 articles published between the first description of the DIEP flap in 1989 and August of 2011, the authors found that the methods used to categorize partial necrosis and fat necrosis were inconsistent. As a result, these surgical outcomes cannot be meaningfully compared among series and centers. In contrast, complete flap failure is an unambiguous and universally reported outcome that represents only a portion of the entire spectrum of flap necrosis. METHODS: The authors created a database of every article with data on DIEP flaps by searching PubMed and Embase for the terms "DIEP," "DIEAP," "epigastric AND perforator," "perforator," and "flap AND reconstruction" and manually reviewing the 14,480 citations the search generated. The authors then reviewed 693 articles with data on DIEP flaps for incidence and other clinical details of flap loss, partial necrosis, and fat necrosis. RESULTS: The authors found a broad range of definitions of partial and fat necrosis based on different parameters (e.g., percentage of flap lost, area of flap lost, necessity of reoperation) that were not directly comparable. Of 152 documented DIEP flap losses, 67 had reported causes: 40 percent (27 of 67) involved venous problems, 28 percent (19 of 67) arterial, and 21 percent (14 of 67) mechanical (pedicle kinking, hematoma). CONCLUSIONS: At present, there is no consensus on the reporting of partial necrosis and flap necrosis. The authors propose a new flap necrosis classification system that prevents ambiguity and allows direct objective comparison of surgical outcomes among centers.