J Reconstr Microsurg 2016; 32(07): 520-527
DOI: 10.1055/s-0036-1581078
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A Novel Method to Estimate the Weight of the DIEP Flap in Breast Reconstruction: DIEP-W, a Simple Calculation Formula Using Paraumbilical Flap Thickness

Kyong-Je Woo
1  Department of Plastic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-gu, Seoul, South Korea
,
Eun-Ji Kim
1  Department of Plastic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-gu, Seoul, South Korea
,
Kyeong-Tae Lee
1  Department of Plastic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-gu, Seoul, South Korea
,
Goo-Hyun Mun
1  Department of Plastic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-gu, Seoul, South Korea
› Author Affiliations
Further Information

Publication History

28 October 2015

04 February 2016

Publication Date:
06 April 2016 (online)

Abstract

Background Preoperative estimation of abdominal flap volume is valuable for breast reconstruction, especially in lean patients. The purpose of this study was to develop a formula to estimate the weight of the deep inferior epigastric artery perforator (DIEP) flap using unidimensional parameters.

Methods We retrospectively collected data on 100 consecutive patients who underwent breast reconstruction using the DIEP flap. Multiple linear regression analysis was used to develop a formula to estimate the weight of the flap. Predictor variables included body mass index, height of the flap, width of the flap, and flap thickness on computed tomography angiographic images at three paraumbilical sites: 5 cm right, left, and inferior from the umbilicus. Then we prospectively tested the accuracy of the developed formula in 38 consecutive patients who underwent breast reconstruction with free DIEP flaps.

Results A calculation formula and a smartphone application, DIEP-W was developed from retrospective analysis (R 2 = 92.7%, p < 0.001). In the prospective study, the average estimated weight was 96.3% of the actual weight, giving the formula a mean absolute percentage error of 7.7% (average differences of 45 g). The flap size in the prospective group was significantly smaller (p < 0.001) and donor-site complications were less (p = 0.002) than those of retrospective group.

Conclusion Surgeons can easily calculate the DIEP weight with varying flap dimensions in a real-time fashion using this formula during preoperative planning and intraoperative design. Estimating the flap weight facilitates economical use of the flap, which can lead to reduced donor-site complications.