Prospective Clinical Trial for Predicting Mastectomy Skin Flap Necrosis with Indocyanine Green Angiography in Implant-Based Prepectoral Breast Reconstruction

Abstract

Background: Indocyanine green angiography (ICG-A) is a useful tool for evaluating mastectomy skin flap (MSF) perfusion during breast reconstruction. However, a standardized protocol for interpreting and applying MSF perfusion after mastectomy has not been established yet. The purpose of this study is to establish criteria for assessing MSF perfusion in immediate implant-based prepectoral breast reconstruction while correlating ICG-A findings with postoperative outcomes METHODS: This prospective observational study was conducted at a single institution and involved patients with breast cancer who underwent mastectomy and immediate implant-based prepectoral breast reconstruction between August 2021 and August 2023. The terms "hypoperfused flap" and "hypoperfused area" were defined according to ICG-A perfusion. MSF exhibited < 30% perfusion, excluding the nipple and the corresponding region, respectively. Data on the hypoperfused flap, hypoperfused area, and MSF necrosis were collected.

Results: Fifty-three breast cases were analyzed. Eight patients developed MSF necrosis (15.1%, 8/53). Of these, two patients underwent surgical debridement and revision within 3 months (3.8%, 2/53). There were nine cases of a hypoperfused flap, eight of which developed MSF necrosis. The hypoperfused flap was a significant predictor of the occurrence of MSF necrosis (p < 0.001). There was a tendency for increased full-thickness necrosis with a wider hypoperfused area.

Conclusions: The hypoperfused flap enabled the prediction of MSF necrosis with high sensitivity, specificity, positive predictive value, and negative predictive value. Considering the presumed correlation between the extent of the hypoperfused area and the need for revision surgery, caution should be exercised when making intraoperative decisions regarding the reconstruction method.

Level of evidence iii: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Keywords: Indocyanine green; Mastectomy; Necrosis; Skin flap.

Fig. 1

ICG-A images for illustrating the hypoperfused flap. a and b Color and grayscale images obtained through ICG-A. The hypoperfused flap characterized by the presence of perfusion below 30% in the upper lateral area and around the incision, excluding the nipple. c and d Color and grayscale images obtained through ICG-A. In this case, the flap is not considered hypoperfused flap because it demonstrates perfusion below 90% only in the nipple. ICG-A, indocyanine green angiography

Fig. 2

a and b are a color image and grayscale image of ICG-A performed immediately after NSM using sizers in a 48-year-old female patient. The hypoperfused area is around the IMF incision area and the lower pole. The hypoperfused area percent ratio of the total breast area is 6.55%. c The image taken on the 1st day after surgery. There is partial-thickness necrosis of the nipple; in the area around the IMF incision, there is a purplish color change. The patient’s wound improved with dressing without surgical intervention. ICG-A, indocyanine green angiography; NSM, nipple-sparing mastectomy; IMF, inframammary fold

Fig. 3

A 52-year-old female patient underwent nipple-sparing mastectomy and immediate implant insertion. a and b are a color image and grayscale image, respectively. The hypoperfused area extends widely around the nipple. The hypoperfused area percent ratio is 27.71%. c In the image taken on the 1st day after surgery, there is only slight redness around the nipple. d In the image taken on the 5th day after surgery, there is a purplish change in the area corresponding to the hypoperfused area of ICG-A. e In the image taken 1 month after surgery, about 1 × 2-cm full-thickness necrosis is visible around the nipple. After 2 weeks, once demarcation occurred, debridement and implant change were performed. f The image taken 1 month after debridement and implant change. Further MSF full-thickness necrosis is observed around the incision site. Subsequently, the patient underwent a conversion to a tissue expander; eventually, due to ongoing wound problems, the tissue expander had to be removed. ICG-A, indocyanine green angiography