Background: During breast reconstruction, predicting contralateral perfusion of the deep inferior epigastric artery perforator flap can help minimize tissue necrosis. This study aimed to quantify the area of contralateral perfusion and identify the factors affecting it. Methods: A retrospective study was conducted on unilateral breast reconstructions with a single perforator-based deep inferior epigastric artery perforator flap, for the period of 2017 to 2019. Data on the distance between the perforator and the umbilicus, and the grade of the midline crossing-over vessel (G0, no vessel; G1, suspicious vessel; G2, definite vessel), were collected. Contralateral perfusion was estimated using intraoperative indocyanine green angiography, and the degree of contralateral circulation based on perforator location was assessed using a response surface methodology analysis. Results: The study included 143 patients (G0, 62; G1, 45; and G2, 36). The average length of transverse contralateral flap perfusion (contralateral circulation area/vertical height of the flap) increased as the crossing-over vessel grade increased (G0, 62.96 ± 20.33 mm; G1, 71.69 ± 20.66 mm; and G2, 81.1 ± 19.32 mm; P = 0.0002). In the response surface methodology analysis, contralateral perfusion was the least when the perforator was located near the umbilicus (G0, within a 10-mm radius; G1, <10-mm transverse distance and 16- to 22-mm vertical distance; and G2, within a 20-mm radius). Conclusions: The umbilicus can interfere with contralateral perfusion; thus, a definite presence of a midline crossing-over vessel ensures robust contralateral perfusion. The results of this study can help surgeons select the optimal single perforator before surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

This is the first study to report on robotic capsulectomy and compare postoperative outcomes with conventional techniques. Robotic systems can make total capsulectomy technically easier for surgeons while contributing to patient safety and aesthetic outcomes. The expansion of robotic capsule surgery is expected, but weighing pros and cons is necessary in further studies.