The Impact of SPY Angiography on Intraoperative Decision Making and Outcomes for Post-Mastectomy Reconstruction

Objective: While the use of intraoperative laser angiography (SPY) is increasing in mastectomy patients, its impact in the operating room to change the type of reconstruction performed has not been well described. The purpose of this study is to investigate whether SPY angiography influences postmastectomy reconstruction decisions and outcomes. Materials and Methods: A retrospective analysis of mastectomy patients with reconstruction at a single institution was performed from 2015–2017. All patients underwent intraoperative SPY after mastectomy but prior to reconstruction. SPY results were defined as ‘good’, ‘questionable’, ‘bad’, or ‘had skin excised’. Complications within 60 days of surgery were compared between those whose SPY results did not change the type of reconstruction done versus those who did. Preoperative and intraoperative variables were entered into multivariable logistic regression models if significant at the univariate level. A p-value <0.05 was considered significant. Results: 267 mastectomies were identified, 42 underwent a change in the type of planned reconstruction due to intraoperative SPY results. Of the 42 breasts that underwent a change in reconstruction, 6 had a ‘good’ SPY result, 10 ‘questionable’, 25 ‘bad’, and 2 ‘had areas excised’ (p<0.01). After multivariable analysis, predictors of skin necrosis included patients with ‘questionable’ SPY results (p<0.01,OR:8.1,95%CI:2.06 – 32.2) and smokers (p<0.01,OR:5.7,95%CI:1.5 – 21.2). Predictors of any complication included a change in reconstruction (p<0.05,OR:4.5,95%CI:1.4–14.9) and ‘questionable’ SPY result (p<0.01,OR:4.4,95%CI:1.6–14.9). Conclusion: SPY angiography results strongly influence intraoperative surgical decisions regarding the type of reconstruction performed. Patients most at risk for flap necrosis and complication post-mastectomy are those with questionable SPY results. Background In recent years, intraoperative laser (SPY) angiography has been shown to be effective in identifying areas of ischemic tissue and predicting skin or nipple areolar necrosis during mastectomies [1–5]. One of the most significant complications following a skin or nipple sparing mastectomy with reconstruction is flap necrosis [6,7]. Consequently, SPY angiography has been found to be a useful adjunct to clinical assessment in identifying and potentially preventing complications such as skin necrosis [2]. While studies have demonstrated the ability of SPY angiography to predict mastectomy flap necrosis, none have investigated the impact of SPY angiography on intraoperative decision making, such as changing the type of reconstruction performed. In order to identify the independent predictive value of SPY angiography for postoperative complications, prior studies have not allowed SPY results to impact intraoperative reconstruction decisions [1]. Other studies have described the usefulness of SPY in identifying areas of flap ischemia intraoperatively so that compromised skin could be excised, resulting in decreased complication rates compared to those who did not use SPY [4]. To date, there are no studies describing whether SPY angiography affects surgical decision making regarding the type of breast reconstruction performed. Nor are there studies evaluating whether SPY angiography results can predict other complications, such as seroma or infection. These complications can result from skin necrosis, but independent predictive values have not been evaluated. Our study aims to describe the impact of SPY angiography on intraoperative decision making regarding type of breast reconstruction. Additionally, we aim to investigate the utility of SPY in predicting other postoperative complications. Materials and Methods Patients After receiving institutional review board approval, a retrospective analysis was performed of a single institution breast care center from 2015–2017. Adult female patients age 18 or older who underwent Nipple Sparing Mastectomy (NSM) or Skin Sparing Mastectomy (SSM), with or without sentinel lymph node biopsy (SLNB) and/ or Axillary Lymph Node Dissection (ALND) were identified. The study included patients with a diagnosis of breast cancer and patients undergoing prophylactic surgery. All mastectomies were performed by Ju T (2019) The Impact of SPY Angiography on Intraoperative Decision Making and Outcomes for Post-Mastectomy Reconstruction Interv Med Clin Imaging, Volume 2(1): 2–5, 2019 one of three breast surgical oncologists at our institution. All patients underwent immediate reconstruction with Tissue Expander (TE) or fixed volume implant during the same procedure by one of three plastic surgeons, and all had intraoperative indocyanine green (ICG, standard dose of 2.5mg/ml with 4ml) SPY angiography using the SPY Elite System to evaluate skin perfusion prior to reconstruction. Variables Preoperative patient variables including age, smoking status (defined as current smoker at the time of surgery), diabetes, obesity (BMI >/= 30kg/m2), breast weight, and exposures (history of chest wall radiation or chemotherapy) along with intraoperative variables including type of surgery (NSM vs SSM) and ALND were compared. SPY results were defined as described by the plastic surgeon in their operative report as ‘good,’ ‘questionable,’ ‘bad ’or‘ areas excised.’ Documentation of planned reconstruction was noted in the preoperative clinic note and the performed reconstruction was identified in the final operative report. A change in intraoperative reconstruction was either placement of an expander rather than implant, minimal expansion of an expander, or no reconstruction at all. Complications assessed included necrosis (full or partial flap or Nipple-Aerola Complex (NAC) necrosis, dehiscence, or those requiring reoperation), infection (abscess, cellulitis or sepsis), seroma (requiring aspiration or surgical intervention), or explantation of implant within 60 days of surgery. These outcomes were compared between those who had SPY results that changed the type of reconstruction performed and those who did not. Statistics Univariate analyses were performed using chi-square tests, Fisher’s exact test, independent sample t-tests, and F-tests in ANOVA for categorical and quantitative variable analysis, respectively. A change in reconstruction was used as the predictor variable with each outcome of interest being the dependent variable tested for significant univariate association. Patient demographics and intraoperative variables were tested for univariate association with our predictor variable to identify possible confounders. These variables were adjusted for in multivariable logistic regression models when the respective univariate p-value was less than 0.1. Covariates in the final multivariable logistic model were considered statistically significant if the p-value was less than 0.05. All statistical analysis was done using SAS version 9.3 (Cary, NC). Results Of the 267 mastectomies identified, 42 breasts from 25 patients (15.7%) underwent a change in the type of reconstruction intraoperatively due to SPY results. Of the 42 changes in reconstruction type, 6 breasts had ‘good’ SPY results, 10 had ‘questionable’ SPY results, 25 had ‘bad’ SPY results, and 2 breasts ‘had areas excised’ (p<0.0001) (Table 1). Of the patients who underwent a change in reconstruction, 39 of 42 breasts (92.8%) had a TE placed instead of implant or a TE placed with lower volume, while 3 breasts (7.1%) did not undergo any reconstruction based on intraoperative assessment. The patient demographics that were statistically significant on univariate analysis in relation to those who had no change versus those who had a change in reconstruction included smoking (p<0.001), obesity (p<0.01), and breast weight (p<0.0001). Age, diabetes, and history of chemotherapy or chest wall radiation were not statistically significant (Table 2). Patients who did not have a change in reconstruction were more likely to have undergone a SSM versus a NSM (p<0.01) and have a ‘good’ SPY result (p<0.0001) compared to those who underwent a change in reconstruction (Table 2). There was a statistically significant increase in complications including necrosis (p<0.01), infection (p<0.01), and seroma (p<0.0001) for patients who had a change in reconstruction based on SPY results compared to those who did not (Table 3). Table 1. SPY results and frequency of intraoperative decision change. All Subjects N=267 Good N=165 (61.8) Questionable N=25 (9.4) Bad N=25 (9.4) Areas excised N=52 (19.5) p-value