An outcome analysis of intraoperative angiography for postmastectomy breast reconstruction

Understanding healing complications in implant-based breast reconstruction using novel metrics for indocyanine green angiography

INTRODUCTION

Indocyanine green (ICG) angiography for the intraoperative evaluation of tissue perfusion is commonly used in implant-based breast reconstruction (IBR). The assessment of ICG images depends on the surgeon's interpretation and is qualitative or semiqualitative in nature. To quantify ICG metrics, this study aimed to apply a novel assessment of fill-rate dynamics to predict wound-healing complications and provide pragmatic assessment tools in IBR.

METHODS

This was a retrospective cohort study of patients who underwent IBR with ICG using the photodynamic eye (PDE-Neo II) qualitative imaging system between April 2021 and September 2023. ICG recordings were reviewed to quantify the relative surface area and fluorescence intensity of visual perfusion deficits using ImageJ. The primary outcome was the incidence of wound-healing complications. t-tests and logistic regression were performed for statistical testing.

RESULTS

A total of 112 patients (201 breasts) were included. The incidence of wound-healing complications was 12.9%. A higher relative surface area of ischemic regions was significantly associated with wound-healing complications (3.3% vs. 0.90%; p = 0.001). The rate of change in the surface area of ischemic regions was significantly associated with wound-healing complications (0.35% per second vs. 1.29% per second; p = 0.003%). On average, the duration of transient ischemic areas was significantly longer in breasts with wound-healing complications (46.0 s vs. 36.0 s, p = 0.01).

CONCLUSION

A transient ischemic area of > 5% of the breast and/or failure to resolve transient ischemic areas after 60 s may predict wound-healing complications and inform surgical reconstructive decision-making in IBR.

Prognostic Prediction of Multiterritory Flap: A Preliminary Clinical Study on the Classification of Priority Developing Artery and Arterial Anastomosis Utilizing Indocyanine Green Angiography

BACKGROUND

Congestion and necrosis are frequent complications in multiterritory flaps. Indocyanine green angiography (ICGA) is a commonly utilized tool for evaluating blood flow and perforator location within the flap; however, there is currently no existing research investigating its potential to predict flap prognosis before surgery.

METHODS

The forehead skin of 50 surgical patients was assessed using preoperative ICGA, enabling observation and classification of the priority developing artery and arterial anastomosis among adjacent arterial perfusion territories during the arterial phase. Subsequently, 5 clinical cases of forehead flap transfer were studied to validate the classification method.

RESULTS

First, the priority developing artery can be classified into 4 types and 5 subtypes, encompassing type Ⅰa: Bilateral ST-As equalization type (9/50), type Ⅰb: unilateral ST-A dominance type (11/50), type II: SOT-As dominance type (14/50), type III: unilateral ST-A plus SOT-A dominance type (6/50), and type IV: bilateral ST-As plus SOT-As equilibrium type (10/50). Second, arterial anastomosis can be divided into 5 types: type I: complete choke anastomosis type (13/50), type II: complete true anastomosis type (7/50), type III: central choke anastomosis type (10/50), type IV: bilateral choke anastomosis type (8/50), and type V: unilateral choke anastomosis type (12/50). Finally, the clinical flap outcomes showed that the ICGA classification could serve as a good prognostic indicator.

CONCLUSIONS

The hemodynamic classification of priority developing artery and arterial anastomosis employed by ICGA has the potential to predict flap prognosis and offer valuable insights for preoperative design and perioperative treatment strategies. More sample size is needed to optimize and validate this classification.

Indocyanine green angiography guidance for vascular preservation in skin and nipple sparing mastectomy

PURPOSE

The skin and/or nipple-sparing approach has become an oncologically sound and desirable choice for women choosing mastectomy. Indocyanine green (ICG) perfusion imaging has been shown to reduce ischemic complications in mastectomy skin flaps. Immediate reconstruction requires a well-vascularized skin flap capable of tolerating full expansion. Identification of the perforating subcutaneous vessels to the skin envelope may allow for better and more consistent blood vessel preservation and flap perfusion.

METHODS

The authors conducted an institutional review board-approved prospective study with 41 patients to assess the feasibility of using ICG perfusion imaging to visualize, cutaneously map, and preserve the vessels that supply the skin flap and nipple-areolar complex. For each patient, the number of vessels initially mapped, the number of vessels preserved, the extent to which each vessel was preserved, and the proportion of the flap with adequate perfusion (as defined by the SPY-Q > 20% threshold) was recorded and analyzed.

RESULTS

Vessels were able to be identified and marked in a high majority of patients (90%). There was a moderate linear relationship between the number of vessels marked and the number preserved. Successful mapping of vessels was associated with lower rates of wound breakdown (p = 0.036). Mapping and preserving at least one vessel led to excellent flap perfusion (> 90%). No increase in complications was observed from utilizing ICG angiography preoperatively.

CONCLUSION

This prospective study using preoperative ICG perfusion mapping demonstrated safety, feasibility, and good prognostic outcomes.

LEVEL OF EVIDENCE

III.

High Rates of Discordant Ureteral Perfusion During Open Ureteral Reconstruction With Indocyanine Green: Does Near-Infrared Fluorescence Imaging Change Management or Stricture Outcomes?

OBJECTIVE

To determine the role of near-infrared fluorescence imaging (NIFI) combined with indocyanine green (ICG) to assess ureteral tissue perfusion in a benign genitourinary reconstruction cohort with a high prevalence of prior abdominopelvic radiation and surgery.

MATERIALS AND METHODS

A prospective, single-surgeon series, between June 2018 and April 2022, of patients who underwent open genitourinary reconstructive surgeries in which NIFI/ICG was utilized to intraoperatively assess ureteral tissue perfusion prior to ureteral anastomosis. Primary outcome was ureteroanastomotic stricture (UAS). Secondary outcomes included impact of NIFI/ICG on surgical decision-making and ureter resection length.

RESULTS

Thirty nine patients, median age 66, underwent 40 multimodality reconstructive surgeries during which NIFI/ICG was utilized in the open setting. Radiation-induced etiology was present in 32 of 40 (80%) patients. UAS occurred in 1 of 57 (1.8%) anastomoses with median follow-up of 23.4 months. Use of NIFI/ICG changed intraoperative decision-making in 63% of cases. Change in intraoperative decision-making was more common in patients with prior abdominopelvic radiation (66%) compared to non-radiated patients (13%), P = .007. Discordance between subjective (white-light) and objective (NIFI/ICG) ureteral perfusion (white-light) occurred in 61% of ureters. Mean length of resected ureter was higher following objective assessment with NIFI/ICG (3.6 cm) versus subjective assessment (white light) conditions (1.8 cm), P = .001.

CONCLUSION

Use of NIFI/ICG was associated with low rates of UAS at 2-year follow-up in a cohort with high prevalence of prior radiation. NIFI/ICG was associated with longer lengths of ureter resection and ureteral perfusion assessment discordance compared to subjective surgeon assessment under white-light conditions.

Perfusion Dynamics during Secondary Flap Debulking with Liposuction

BACKGROUND

 Lower extremity trauma often necessitates reconstruction with flap transfer. One of the reconstructive goals is a thin soft tissue coverage with appropriate contour. Therefore, a secondary debulking of the flap is usually performed.

METHODS

 Debulking through conventional lipectomy is compared with liposuction followed by excision of the defatted flap excess. Demographic data, surgical details, and postoperative outcomes are compared and analyzed. The perfusion dynamics of the flaps undergoing liposuction debulking are studied by means of perioperative indocyanine green fluorescence angiography, as well as postoperative laser Doppler imaging.

RESULTS

 Patients undergoing lipectomy (n = 69; 57.5%) or liposuction (n = 51; 42.5%) debulking had a similar rate of postoperative complications. Partial necrosis was observed in 7.2% (lipectomy) versus 7.8% (liposuction) of flaps. Fluorescence angiography showed a substantial decrease in flap perfusion following the infiltration with an epinephrine-containing tumescent solution (74.3% ± 8.2% prior to infiltration versus 16.8% ± 7.1% after infiltration; p < 0.001), resulting in a dark flap appearance. Laser Doppler imaging confirmed the hypoperfusion on postoperative day 1.

CONCLUSION

 Secondary debulking of a lower extremity flap can be safely and efficiently performed through liposuction combined with peripheral excision of the defatted flap in a single stage. Perfusion studies may show a misleading hypoperfusion of the defatted flap, which does not accurately predict subsequent necrosis or complications.

Use of Ambient Light Compatible Fluorescence-Guided Surgical Technology for Objective Assessment of Flap Perfusion in Autologous Breast Reconstruction

BACKGROUND

 Decreased autologous flap vascular perfusion can lead to secondary procedures. Fluorescence angiography during surgery reduces the probability of repeat surgery but suffers from interpretation variability. Recently, the OnLume Avata System was developed, which evaluates real-time vascular perfusion in ambient light. This study aims to predict complications in autologous breast reconstruction using measures of relative intensity (RI) and relative area (RA).

METHODS

 Patients undergoing autologous breast reconstruction underwent intraoperative tissue perfusion assessment using the OnLume Avata System. Post-hoc image annotation was completed by labeling areas of the flap interpreted to be "Well Perfused," "Questionably Perfused," and "Under Perfused." RIs and RAs were calculated for the marked areas. Primary complications of interest were overall complication rate, fat and mastectomy skin flap necrosis, and surgical revision. Logistic regression was applied to determine the odds of developing a complication based on RI and RA for each image.

RESULTS

 A total of 25 patients (45 flaps) were included. In total, 17 patients (68%) developed at least one complication. Patients who developed any complication (p = 0.02) or underwent a surgical revision for complications (p = 0.02) had statistically lower RI of under-perfused portions of the flap. Patients with greater areas of under-perfused flap had a significantly higher risk of developing fat necrosis (odds ratio [OR]: 5.71, p = 0.03) and required a revision operation (OR: 1.10, p = 0.01).

CONCLUSION

 Image-based interpretation using the OnLume Avata System correlated with the risk of developing postoperative complications that standard fluorescence imaging systems may not appreciate. This information can benefit surgeons to improve perfusion assessment and intraoperative decision-making.

Prediction of pedicled flap survival preoperatively by operating indocyanine green angiography at 1,450 nm wavelength: an animal model study

Background

Predicting flap viability benefits patients by reducing complications and guides flap design by reducing donor areas. Due to varying anatomy, obtaining individual vascular information preoperatively is fundamental for designing safe flaps. Although indocyanine green angiography (ICGA) is a conventional tool in intraoperative assessment and postoperative monitoring, it is rare in preoperative prediction.

Methods

ICGA was performed on 20 male BALB/c mice under five wavelengths (900/1,000/1,100, /1,250/1,450 nm) to assess vascular resolution after ICG perfusion. A "mirrored-L" flap model with three angiosomes was established on another 20 male BALB/c mice, randomly divided into two equal groups. In Group A, a midline between angiosomes II and III was used as a border. In Group B, the points of the minimized choke vessel caliber marked according to the ICG signal at 1,450 nm wavelength (ICG1450) were connected. Necrotic area calculations, pathohistological testing, and statistical analysis were performed.

Results

The vascular structure was clearly observed at 1,450 nm wavelength, while the 900 to 1,100 nm failed to depict vessel morphology. Necrosis was beyond the borderline in 60% of Group A. Conversely, 100% of Group B had necrosis distal to the borderline. The number of choke vessels between angiosomes II and III was positively correlated with the necrotic area (%). The pathohistological findings supported the gross observation and analysis.

Conclusion

ICG1450 can delineate the vessel structure in vivo and predict the viability of pedicled skin flaps using the choke vessel as the border between angiosomes.

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

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 .

Predicting Nipple Necrosis with a "Lights-on" Indocyanine Green Imaging System: A Report of Two Patients

Nipple-areolar complex (NAC) necrosis is a devastating complication in nipple-sparing mastectomies (NSMs) that significantly impacts patient's quality of life. The use of fluorescence angiography for intraoperative assessment of mastectomy skin flap perfusion in NSM has been successfully described and can be utilized to help guide surgical decision-making. Recently, a novel fluorescence-guided surgical imager was developed, OnLume Avata System (OnLume Surgical, Madison, WI), which provides intraoperative evaluation of vascular perfusion in ambient light. In this case report, we describe the use of OnLume fluorescence-guided surgery technology to help aid in clinical decision-making for two breast reconstruction cases with concern for intraoperative nipple hypoperfusion.

Risk Factors for Skin Flap and Nipple-Areolar Necrosis in Patients Undergoing Nipple-Sparing Mastectomy With Deep Inferior Epigastric Perforator Flap Reconstruction

INTRODUCTION

Nipple-sparing mastectomy (NSM) with deep inferior epigastric perforator (DIEP) flap reconstruction is a surgical option for select patients with or at risk of breast cancer. However, post-operative skin flap and nipple-areolar complex (NAC) necrosis remain common complications. This study aimed to identify factors associated with necrosis in patients undergoing NSM with DIEP reconstruction.

METHODS

A retrospective cohort study was performed from 2015 to 2023. 74 variables were analyzed in patients undergoing NSM with DIEP. Patients were stratified into 3 groups based on post-operative skin/NAC necrosis: none, partial thickness, and full thickness. Comparative and descriptive statistics were performed via t-tests, ANOVA, and chi-squared tests.

RESULTS

34 women with 31 breast cancers met inclusion. 44% experienced necrosis: 15% partial thickness and 29% full thickness. The majority were white (85.3%) with mean age of 50 years (SD = 9.11). In patients with immediate DIEP reconstruction, hypoperfused areas identified by SPY angiography increased risk of necrosis (P = .012). Approximately 50% of both partial thickness and full thickness necrosis patients had concerns on SPY angiography. Former smokers in the full thickness necrosis group had more pack years than those without necrosis (9 vs .65 pack years, P = .035).

CONCLUSION

In patients receiving NSM with DIEP flap reconstruction, those with hypoperfusion on SPY angiography and longer smoking history had higher necrosis rates. This supports the continued used of SPY angiography and the role of pre-operative counseling in former smokers with increased pack years on their risk of necrosis and the role of preventative measures in the perioperative setting.

Intraoperative Near-infrared Spectroscopy Can Predict Skin Flap Necrosis

Background

The study aimed to validate the previously identified capacity of near-infrared spectroscopy (NIRS) to detect clinically relevant differences in tissue perfusion intraoperatively.

Methods

Consecutive patients undergoing oncologic resection requiring flap reconstruction were analyzed. Clinicians were blinded to tissue oxygen saturation (StO2) measurements taken intraoperatively. Measurements were taken at (1) control areas not affected by the procedure, (2) areas at risk of necrosis based on distal location, and (3) areas of skin flap necrosis (SFN) identified during the follow-up period. Mean StO2 values were compared using a single-sample t test and analysis of variance (ANOVA) to determine differences in oxygenation.

Results

There were 102 patients included from April 2018 to May 2019. Reconstruction was undertaken following resection for breast cancer (46), melanoma (35), sarcoma (9), and other cutaneous malignancies (12). Breast reconstruction involved 38 alloplastic reconstructions and eight autologous free flaps. Other skin flap reconstruction involved 42 local/regional skin flaps, 13 pedicled flaps, and one free flap. Eighteen patients (17.6%) developed SFN. Mean intraoperative StO2 measurements for control areas, areas at risk, and areas of SFN were 74.8%, 70.9%, and 54.3%, respectively. StO2 values equal to or less than 60% were highly specific (96%) for SFN, whereas StO2 values above 85% were highly sensitive (96%) to rule out SFN.

Conclusion

These results further support the use of NIRS to objectively assess variations in skin flap oxygenation and tissue perfusion that are correlated with the development of postoperative SFN.

Utility of Intraoperative Intrinsic Near-Infrared Imaging for Primary Hyperparathyroidism in Multiple Endocrine Neoplasia Type 1

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder caused by mutations in the tumor suppressor gene MEN1 and is characterized by parathyroid, pancreatic islet, and anterior pituitary tumors. Primary hyperparathyroidism is the most characteristic finding in MEN1, and intraoperative identification and accurate removal of the diseased parathyroid glands are vital since incomplete excision results in recurrence. This case report describes a 59-year-old woman who had pancreatic islet cell tumors and pituitary tumors and underwent selective transsphenoidal adenomectomy. Based on her medical history and examination, the diagnosis of primary hyperparathyroidism in MEN1 was made, and she underwent total parathyroidectomy with autotransplantation with SPY-Elite®️ Fluorescence Imaging (Stryker Corp., Kalamazoo, MI). Intraoperative identification of the parathyroid glands using autofluorescence with real-time intrinsic near-infrared (NIR) imaging made it easier to detect all of the parathyroid hyperplasia. After the surgery, she had hypoparathyroidism and continued with her oral calcium and vitamin D supplementation to maintain normal calcium levels during follow-up. Herein, we would like to advocate that the use of parathyroid gland autofluorescence with real-time intrinsic NIR imaging may be useful for identifying parathyroid tumors in patients with primary hyperparathyroidism in MEN1.

Evolution of Indocyanine Green Fluorescence in Breast and Axilla Surgery: An Australasian Experience

The evolution of indocyanine green (ICG) fluorescence in breast and axilla surgery from an Australasian perspective is discussed in this narrative review with a focus on breast cancer and reconstruction surgery. The authors have nearly a decade of experience with ICG in a high-volume institution, which has resulted in publications and ongoing future research evaluating its use for predicting mastectomy skin flap perfusion for reconstruction, lymphatic mapping for sentinel lymph node (SLN) biopsy, and axillary reverse mapping (ARM) for prevention of lymphoedema. In the authors' experience, routine use of ICG angiography during breast reconstruction postmastectomy was demonstrated to be cost-effective for the reduction of ischemic complications in the Australian setting. A novel tracer combination, ICG-technetium-99m offered a safe and effective substitute to the "gold standard" dual tracer for SLN biopsy, although greater costs were associated with ICG. An ongoing trial will evaluate ARM node identification using ICG fluorescence during axillary lymph node dissection and potential predictive factors of ARM node involvement. These data add to the growing literature on ICG and allow future research to build on this to improve understanding of the potential benefits of fluorescence-guided surgery in breast cancer and reconstruction surgery.

Mastectomy Skin Flap Stability Prediction Using Indocyanine Green Angiography: A Randomized Prospective Trial

BACKGROUND

The first step in successful breast reconstruction is obtaining a stable skin flap. Indocyanine green (ICG) angiography has recently been studied for its value and usefulness in predicting the stability of skin flaps; however, relevant prospective studies of its clinical efficacy are limited.

OBJECTIVES

The aim of this study was to prospectively investigate the clinical impact on breast reconstruction outcomes of the intraoperative use of ICG angiography.

METHODS

Between March and December 2021, 64 patients who underwent immediate breast reconstruction at the authors' institution were prospectively enrolled. They were classified into an experimental group (n = 39; undergoing ICG angiography) and a control group (n = 25; undergoing gross inspection alone). In the absence of viable skin, debridement was performed at the surgeon's discretion. Skin complications were categorized as skin necrosis (the transition of the skin flap to full-thickness necrosis) or skin erosion (a skin flap that did not deteriorate or become necrotic but lacked intactness).

RESULTS

The 2 groups were matched in terms of basic demographic characteristics and incision line necrosis ratio (P = .354). However, intraoperative debridement was significantly more frequent in the experimental group (51.3% vs 48.0%, P = .006). The authors additionally classified skin flap necrosis into partial- and full-thickness necrosis, with a higher predominance of partial-thickness necrosis in the experimental vs control group (82.8% vs 55.6%; P = .043).

CONCLUSIONS

Intraoperative ICG angiography does not directly minimize skin erosion or necrosis. However, compared to gross examination alone, it enables surgeons to perform a more active debridement during surgery, thereby contributing to a lower incidence of advanced skin necrosis. In breast reconstruction, ICG angiography may be useful for assessing the viability of the postmastectomy skin flap and could contribute to successful reconstruction.

LEVEL OF EVIDENCE

4.

Outcome analysis of free flap reconstruction for head and neck cancer with intraoperative indocyanine green angiography

BACKGROUND

Intraoperative indocyanine green (ICG) angiography is used in free flap surgery to evaluate the patency of vessel anastomosis. This study evaluated the outcomes of intraoperative ICG angiography in free flap surgery for head and neck cancer.

MATERIALS AND METHODS

This was a retrospective study of free flap reconstruction for head and neck cancer performed between 2015 and 2021. The outcomes analyzed were the total flap failure rate, re-exploration rate, and flap salvage rate. Differences in outcomes were compared in patients treated using intraoperative ICG angiography and those treated without.

RESULTS

Of the 520 free flap surgeries in the 486 enrolled patients, 259 cases underwent intraoperative ICG angiography. In this group, there were 10 (3.9%) cases of total flap failure. In the non-ICG group, there were 22 cases (8.4%). There were 35 (13.5%) cases requiring re-exploration in the ICG group and 40 (15.3%) in the non-ICG group. The difference was not statistically significant. The flap salvage rate was 75.8% (25/33) in the ICG group and 51.4% (18/35) in the non-ICG group, which was a significant difference.

CONCLUSION

We found that free flap surgery with intraoperative ICG angiography significantly decreased total flap failure rate and significantly increased salvage rate but did not significantly affect the re-exploration rate.

Prepectoral Versus Subpectoral Implant-Based Reconstruction: How Do We Choose?

Aspects of a patient's lifestyle, their state of health, breast size, and mastectomy skin flap quality are factors that influence the suggested plane of dissection in implant-based breast reconstruction. This article aims to review developments in prosthetic breast reconstruction and provide recommendations to help providers choose whether prepectoral or subpectoral reconstruction in the best approach for each of their patients.

Flap perfusion assessment with indocyanine green angiography in deep inferior epigastric perforator flap breast reconstruction: A systematic review and meta-analysis

BACKGROUND

Indocyanine green angiography (ICG-A) has been widely applied for intraoperative flap assessment in DIEP flap breast reconstruction. However, the beneficial effect of ICG-A in DIEP flap breast reconstruction is still uncertain and no standardized protocol is available. This study aims to analyze the clinical outcome and comprehensively review protocols of this field.

METHODS

A systematic review was conducted in MEDLINE, EMBASE, and Cochrane CENTRAL databases until September 15, 2022. Studies on the utility of intraoperative ICG-A in DIEP breast reconstruction were included. Data reporting reconstruction outcomes were extracted for pooled analysis.

RESULTS

A total of 22 studies were enrolled in the review, among five studies with 1021 patients included in the meta-analysis. The protocols of ICG-A assessment of DIEP flap varied among studies. According to the pooled results, the incidence of postoperative fat necrosis was 10.89% (50 of 459 patients) with ICG-A and 21.53% (121 of 562 patients) with clinical judgment. The risk for postoperative fat necrosis was significantly lower in patients with intraoperative ICG-A than without (RR 0.47 95% CI 0.29-0.78, p = .004, I2  = 51%). Reoperation occurred in 5 of 48 patients (10.42%) in the ICG-A group and in 21 of 64 patients (32.82%) in the control group summarized from reports in two studies. The risk for reoperation was lower in the ICG-A group than in the control group (RR 0.41 95% CI 0.18-0.93, p = .03, I2  = 0%). Other complications, including flap loss, seroma, hematoma, dehiscence, mastectomy skin necrosis, and infection, were comparable between the two groups. Heterogeneities among studies were acceptable. No significant influence of specific studies was identified in sensitivity analysis.

CONCLUSIONS

ICG-A is an accurate and reliable way to identify problematic perfusion of DIEP flaps during breast reconstruction. Protocols of ICG-A differed in current studies. Intraoperative ICG-A significantly decreases the rate of fat necrosis and reoperation in patients undergoing DIEP breast reconstruction. The synthesized results should be interpreted sensibly due to the sample size limitation. RCTs on the outcomes and high-quality studies for an optimized ICG-A protocol are still needed in the future.

Point-of-Care Tissue Oxygenation Assessment with SnapshotNIR for Alloplastic and Autologous Breast Reconstruction

In breast reconstruction, mastectomy and free flaps are susceptible to vascular compromise and tissue necrosis. The SnapshotNIR device (Kent Imaging, Calgary, AB, Canada) utilizes near-infrared spectroscopy to measure tissue oxygen saturation (StO₂) and hemoglobin concentration. Here, we report on the use of this device for StO₂ monitoring among patients receiving alloplastic or autologous breast reconstruction.

Methods

Patients receiving immediate alloplastic reconstruction after mastectomy or autologous reconstruction were enrolled. Preoperative, intraoperative, and postoperative images were taken of the flaps. StO₂ and hemoglobin were measured at the following locations: superior and inferior breast, free flap skin paddle (when applicable), and un-operated control skin. Linear mixed effects model for repeated measurements was used to model measurements to estimate the area effect difference across time, time effect difference across area, and pairwise comparisons between two areas at each time point.

Results

Thirty-two breasts underwent alloplastic reconstruction; 38 breasts underwent autologous reconstruction. No enrollees developed skin necrosis. StO₂ was highest after mastectomy and closure in alloplastic reconstructions. StO₂ was observed to decline at follow-up in autologous reconstructions. Mean preoperative StO₂ was highest in breasts that had previously undergone mastectomy and alloplastic reconstruction.

Conclusions

The SnapshotNIR device detected normal spatial and temporal differences in tissue oxygenation over the operative course of alloplastic and autologous breast reconstruction. A multi-institutional, prospective clinical trial is needed to determine the sensitivity and specificity of this device for detecting skin flap necrosis.

Role of Indocyanine Green Angiography in Free Flap Surgery: A Comparative Outcome Analysis of a Single-Center Large Series of 877 Consecutive Free Flaps

Purpose  This study aims to assess and validate the role and cost-effectiveness of indocyanine green angiography (ICGA) in free flap surgery outcomes. A new intraoperative protocol of whole-body surface warming (WBSW) for all free flap surgeries during the strategic "microbreaks" is also described. Methods  A retrospective analysis of 877 consecutive free flaps, performed over 12 years, is presented. The results of the ICGA group ( n  = 438) were compared with the historical No-ICGA group ( n  = 439), and statistical significance was calculated for three crucial flap-related adverse outcomes and cost-effectiveness. ICGA was also used as a tool to show the effect of WBSW on free flaps. Results  ICGA showed a notably strong statistical significance in decreasing two outcome parameters, namely, partial flap loss and re-exploration rate. It was also cost-effective. ICGA also demonstrated the positive role of WBSW in increasing flap perfusion. Conclusions  Our study shows that the usage of ICGA for intraoperative assessment of flap perfusion can significantly reduce the partial flap loss and re-exploration rate in free flap surgeries in a cost-effective manner. A new protocol of WBSW is also described and recommended to increase flap perfusion in all free flap surgeries.

Predicting Mastectomy Skin Flap Necrosis: A Systematic Review of Preoperative and Intraoperative Assessment Techniques

Mastectomy skin-flap necrosis (MSFN) is one of the most feared complications of immediate implant-based breast reconstruction (IIBR). Traditionally, mastectomy skin-flap viability was based only on surgeons' clinical experience. Even though numerous studies have already addressed the patients' risk factors for MSFN, few works have focused on assessing quality of breast envelope. This review investigates mastectomy's flap viability-assessment methods, both preoperative (PMFA) and intraoperative (IMFA), to predict MSFN and its sequalae. Between June and November 2022, we conducted a systematic review of Pubmed/MEDLINE and Cochrane electronic databases. Only English studies regarding PMFA and IMFA applied to IIBR were selected. The use of digital mammography, ultrasound, magnetic resonance imaging, and a combination of several methods before surgery was shown to be advantageous by several authors. Indocyanine performed better than other IMFA, however both thermal imaging and spectroscopy demonstrated novel and promising results. Anyway, the best prediction comes when preoperative and intraoperative values are combined. Particularly in prepectoral reconstruction, when mastectomy flaps are essential to determine a successful breast reconstruction, surgeons' clinical judgment is insufficient in assessing the risk of MSFN. Preoperative and intraoperative assessment techniques play an emerging key role in MSFN prediction. However, although there are several approaches to back up the surgeon's processing choice, there is still a dearth of pertinent literature on the subject, and more research is required.

Indocyanine Green Angiography Overpredicts Postoperative Necrosis Compared to Multispectral Reflectance Imaging

BACKGROUND

Sufficient perfusion is foundational to successful reconstructive surgery. Various technologies have been developed to help determine whether tissue is adequately perfused, or whether it will be prone to necrosis postoperatively. Indocyanine green (ICG) angiography is one such method that uses fluorescence and analyzes tissue perfusion. Multispectral reflectance imaging (MSRI) is an alternative technology that analyzes optical properties of oxygenated and deoxygenated hemoglobin to determine tissue viability. Because tissue in low-perfusion states may still survive because of sufficient oxygenation, the authors hypothesized that compared to MSRI, ICG angiography overpredicts necrosis, potentially resulting in unnecessary resection of viable tissue. This study expands on preliminary work to investigate this hypothesis.

METHODS

This was a prospective cohort of patients undergoing prepectoral direct implant reconstruction at a single institution. Each patient was examined intraoperatively with both ICG angiography and MSRI. Decisions to resect tissue were made in conjunction with MSRI and ICG images collected purely for data analysis. Patients were followed postoperatively for at least 2 months for signs of postoperative necrosis.

RESULTS

Fifty-three cases were included. ICG angiography accurately predicted viability in 40 of 40 patients (100%) and incorrectly predicted necrosis in 11 of 13 patients (84.6%). Simultaneously, MSRI predicted necrosis in zero patients and accurately predicted viability in 51 of 53 patients (96.2%). There was no statistically significant difference in demographic data among patients predicted to experience necrosis by means of ICG angiography versus those predicted to have entirely viable tissue.

CONCLUSION

This study suggests that ICG angiography is prone to overpredicting postoperative necrosis in comparison to MSRI.

CLINICAL RELEVANCE STATEMENT

This study suggests that multispectral reflectance imaging may benefit practicing plastic surgeons in determining the likelihood of postoperative necrosis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, II.

Characterizing Outcomes of Medial and Lateral Perforators in Deep Inferior Epigastric Perforator Flaps

BACKGROUND

 Perforators are typically found in rows in the deep inferior epigastric perforator (DIEP) flap. As methods to assess flap perfusion continue to improve, surgeons may be more likely to select perforators traditionally avoided. The purpose of this article is to describe clinical outcomes based on row and number of perforators to reevaluate flap and abdominal donor site morbidity.

METHODS

 A retrospective analysis was performed on patients who underwent breast reconstruction with DIEP flaps by four microsurgeons from 2013 to 2020. The row and number of perforators were determined from operative reports. Chi-square and t-test or nonparametric Fisher's exact test and Wilcoxon two-sample test were used for discrete and continuous variable, respectively, as applicable. Logistic regression was used for multivariable analyses.

RESULTS

 Of 628 flaps, 305 were medial row (58.7%), 159 were lateral row (30.6%), and 55 had both rows (10.6%). Partial flap loss was higher in both rows (p = 0.003). Fat necrosis was higher with medial (p = 0.03) and both rows (p = 0.01) when compared with lateral using multivariable analysis. Hernia or bulge was higher in lateral row flaps (lateral: 8/157, 5.1%; medial, 5/299, 1.7%; both, 0/55; p = 0.05); however, mesh was more commonly used in both row flaps (p = 0.05). There was no difference in fat necrosis or abdominal morbidity between single and multiple perforators.

CONCLUSION

 There was no difference in fat necrosis based on the number or row of perforators. The lateral row provides adequate perfusion but may be associated with an elevated risk of hernia or bulge. Patients may benefit from mesh, especially when both rows are dissected.

Trends in outcomes with adoption of indocyanine green angiography in postmastectomy reconstruction

BACKGROUND

Indocyanine green angiography (ICGA) aims to reduce ischaemic complications by supplementing intraoperative perfusion assessment of mastectomy flaps. Learning curves for this technology have not been analysed. We evaluated changes in patient outcomes with increasing case volume after ICGA adoption in postmastectomy reconstruction.

METHODS

Single-institution retrospective analysis of 320 implant-based reconstructions following mastectomy using ICGA from 2015, when it was introduced, to 2021. Cases chronologically divided into tertiles and complications amongst groups evaluated. Trends in ischaemic complications plotted using weighted moving average. CUSUM analysis determined after how many cases plateau was reached. Number of ischaemic complications prior to plateau calculated with AUC analysis.

RESULTS

Ischaemic complications decreased over time (Group 1, 15.1%; Group 2, 11.2%; Group 3, 4.7%, P = 0.034). Cases of delayed reconstruction increased over time (Group 1, 6.6%; Group 2, 28%; Group 3, 22.4%; P < 0.001). Our institution reached plateau of 10% ischaemic complications after 160 cases. Mean incidence of ischaemic complications decreased from 16.9% during the first 160 cases to 3.8% after plateau was reached (P < 0.001). Eleven extra breasts (6.9%) experienced ischaemic complications, that may have been avoided if operated by surgeons after the first 160 cases.

CONCLUSIONS

There was increased tendency towards a conservative approach of delaying reconstruction and decreased rates of ischaemic complications with increasing case volume after ICGA implementation. A significant number of cases were needed to reach plateau of minimal ischaemic complications. This data could encourage development of standardized protocols for this technology to shorten learning curves for improved patient outcomes.

Intraoperative Fluorescence Angiography in Implant-Based Breast Reconstruction: Identifying Risk Factors and Outcomes

BACKGROUND

Intraoperative fluorescence angiography (FA) has been described as a useful adjunct to physical examination in predicting mastectomy skin flap viability for immediate breast reconstruction. Its use has been described as a screening tool for mastectomy skin flap viability as well as a test used only for patients at high risk for mastectomy skin flap loss. We performed a national database review of implant-based breast reconstruction surgeries to determine the practice patterns of FA in this patient cohort and to determine if this technology impacted clinical outcomes.

METHODS

A national insurance claims database was reviewed to select patients having undergone direct-to-implant (DTI) and immediate tissue expander (TE) placement with and without intraoperative FA as well as patients who had FA at the time of mastectomy without reconstruction. Patient characteristics that prompted FA and postoperative outcomes with and without FA were evaluated to determine its clinical impact in the observed practice pattern.

RESULTS

Of the 48,464 patients identified, 836 had FA. More than twice as many patients undergoing DTI had FA than patients undergoing immediate TE placement (10.4% vs 5%, P < 0.0001). Twelve percent of patients receiving FA at the time of mastectomy had reconstruction delayed. Fluorescence angiography was associated with a trend toward lower overall complication rates in DTI patients (8.0% vs 11.9% without FA) but a significantly higher overall complication rate with immediate TE placement (13.8% vs 10.5% without FA, P = 0.018) and was associated with higher reoperation (12.0% vs 8.3% without FA, P = 0.037) in the TE group. There was no difference in other individual complications, readmission, or explantation for either clinical group with and without FA. Regression analysis identified obesity (odds ratio, 1.32; P < 0.001) and younger age (odds ratio, 1.74; P < 0.001) to be associated with performing FA, whereas obesity, diabetes, and tobacco use were associated with higher complication rates.

CONCLUSIONS

Younger and otherwise healthier obese patients were more likely to have FA. A greater proportion of DTI patients had FA than TE patients with improved outcomes in the former group and worse outcomes in the latter group. Obesity, tobacco use, and diabetes were associated with worse outcomes, whereas only obesity was associated with FA use.

Intraoperative Optical and Fluorescence Imaging of Blood Flow Distributions in Mastectomy Skin Flaps for Identifying Ischemic Tissues

SUMMARY

Insufficient blood flow causes mastectomy skin flap necrosis in 5 to 30 percent of cases. Fluorescence angiography with the injection of indocyanine green dye has shown high sensitivities (90 to 100 percent) but moderate specificities (72 to 50 percent) in predicting mastectomy skin flap necrosis. However, a number of challenging issues limit its wide acceptance in clinical settings, including allergic reaction, short time-window for observation, and high cost for equipment and supplies. An emerging inexpensive speckle contrast diffuse correlation tomography technology enables noninvasive, noncontact, and continuous three-dimensional imaging of blood flow distributions in deep tissues. This preliminary study tested the hypothesis that speckle contrast diffuse correlation tomography and indocyanine green-fluorescence angiography measurements of blood flow distributions in mastectomy skin flaps are consistent. Eleven female patients undergoing skin-sparing or nipple-sparing mastectomies were imaged sequentially by the dye-free speckle contrast diffuse correlation tomography and dye-based commercial fluorescence angiography (SPY-PHI). Resulting images from these two imaging modalities were co-registered based on the ischemic areas with the lowest blood flow values. Because the ischemic areas have irregular shapes, a novel contour-based algorithm was used to compare three-dimensional images of blood flow distribution and two-dimensional maps of indocyanine green perfusion. Significant correlations were observed between the two measurements in all contours from a selected area of 10 × 10 mm 2 with the lowest blood flow ( r ≥ 0.78; p < 0.004), suggesting that speckle contrast diffuse correlation tomography provides the information for identifying ischemic tissues in mastectomy skin flaps. With further optimization and validation in large populations, speckle contrast diffuse correlation tomography may ultimately be used as a noninvasive and inexpensive imaging tool for intraoperative assessment of skin flap viability to predict mastectomy skin flap necrosis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, II.

Tissue Expander-Based Breast Reconstruction at a Major Safety-Net Hospital: Managing the Outsized Risk of Infection

Background

Immediate tissue expander (TE) breast reconstruction is reported to have the highest rate of postoperative infection among reconstructive modalities. The risk of infection is higher among patients treated at safety-net hospitals.

Objectives

The goal of this study was to identify significant contributing factors to the elevated infection risk at our major safety-net institution.

Methods

A retrospective chart review was conducted on all TE-based reconstruction patients with a diagnosis of postoperative infection between 2015 and 2019. Preoperative, perioperative, and postoperative risk factors for infection were determined and compared across patient and procedure demographics.

Results

Two hundred forty-three patients, for a total of 412 breast reconstructions, were included in our study. Significant preoperative selection factors were identified to contribute to the elevated risk of infection, including the following: older age, higher BMI, and diabetes. Significant intraoperative and postoperative contributing factors included greater mastectomy weight, larger TE's and intraoperative fill volume, and longer drain duration. Doxycycline treatment for infected patients resulted in a significantly higher rate of resolution.

Conclusions

Safety-net hospital population patients undergoing TE breast reconstruction are at higher risk for postoperative infection. Personal and procedural risk factors are identified. Balancing the benefits of immediate breast reconstruction with TEs with the elevated risk of postoperative infection remains challenging. Implementation of more stringent eligibility criteria may help mitigate the risk of infection.

Level of Evidence 4

Defining Mastectomy Skin Flap Necrosis: A Systematic Review of the Literature and a Call for Standardization

BACKGROUND

Mastectomy skin flap necrosis following breast reconstruction may lead to wound dehiscence, infection, implant exposure, and reconstructive failure. The absence of a standardized definition for it has led to variation in estimated incidence, from as low as 2 percent to greater than 40 percent. The authors systematically reviewed the literature on mastectomy skin flap necrosis to characterize existing definitions and provide a framework for future classification.

METHODS

A systematic review of the PubMed and Cochrane databases identified studies reporting a discrete definition of mastectomy skin flap necrosis and corresponding outcomes in breast reconstruction. Provided definitions were extracted, categorized, and comparatively analyzed.

RESULTS

Fifty-nine studies met inclusion criteria, with a combined total of 14,368 patients and 18,920 breasts. Thirty-four studies (57.6 percent) reported mastectomy skin flap necrosis solely as a function of total breasts, and 11 (18.6 percent) reported mastectomy skin flap necrosis solely as a function of total patients. Only 14 studies (23.7 percent) provided two separate rates. The overall rate of mastectomy skin flap necrosis was 10.4 percent (range, 2.3 to 41.2 percent) and 15.3 percent (range, 4.7 to 39.0 percent), when reported per breast or per patient, respectively. Studies were categorized by mastectomy skin flap necrosis definition, including intervention (n = 33), depth (n = 20), area (n = 4), and timing (n = 2). Mastectomy skin flap necrosis rates were highest in studies defining necrosis by depth (15.1 percent), followed by intervention (9.6 percent), timing (6.4 percent), and area (6.3 percent). Necrosis rates among studies defining mastectomy skin flap necrosis by intervention, depth, and area were found to be statistically different (p < 0.001).

CONCLUSIONS

Reported mastectomy skin flap necrosis definitions and outcomes vary significantly in the existing literature. For accurate characterization and quantification, a clear, simplified, consensus definition must be adopted.

Cost-effectiveness of indocyanine green angiography in postmastectomy breast reconstruction

BACKGROUND

Mastectomy skin flap necrosis is a major complication of skin- or nipple-sparing mastectomy. Indocyanine green angiography (ICGA) is a novel technology that can identify flaps at risk of necrosis, but there is paucity of cost-effectiveness data particularly in the Australian context. We evaluated its cost-effectiveness in breast reconstruction surgery.

METHODS

Single-institution retrospective study of 295 implant-based breast reconstructions using ICGA compared with 228 reconstructions without ICGA from 2015 to 2020. Costs were calculated using Medicare item numbers and micro-costing analysis. Break-even point analysis determined the number needed to break-even. Cost-utility analysis compared probabilities of ischaemic complications and utility estimates derived from surveys of surgeons to fit into a decision model.

RESULTS

There were 295 breast reconstructions using ICGA with a total cost of AU$164,657. The average cost of treating an ischaemic complication was AU$21,375. Use of ICGA reduced the ischaemic complication rate from 14.9% to 8.8%. Ischaemic complications were prevented in 18 breasts resulting in gross cost savings of AU$384,745 and net savings of AU$220,088. Three hundred eighteen cases using ICGA are needed to break-even. The decision model demonstrated a baseline cost difference of AU$1,179, a quality-adjusted life-years (QALY) difference of 1.77, and an incremental cost-utility ratio (ICUR) of AU$656 per QALY favouring ICGA.

CONCLUSIONS

Routine use of ICGA during implant-based breast reconstruction is a cost-effective intervention for the reduction of ischaemic complications in the Australian setting. ICGA use was associated with a gain of 1.77 additional years of perfect health at a cost of AU$656 more per year.

Assessment of wound perfusion with near-infrared angiography: A prospective feasibility study

•

There are no validated technologies for skin perfusion assessment at time of laparotomy closure.

•

This prospective non-randomized study failed to demonstrate feasibility of skin perfusion measurement using NIR angiography.

•

Successful subjective perfusion assessment with NIR angiography suggests an ongoing role for investigation of this technology.

Objective

To assess the feasibility of quantitatively measuring skin perfusion before and after suture or staple skin closure of vertical laparotomies using indocyanine green (ICG) uptake with near-infrared angiography.

Methods

This was a prospective, non-randomized feasibility study of patients undergoing surgery with a gynecologic oncology service from 2/2018–8/2019. Feasibility was defined as the ability to quantitatively measure ICG uptake adjacent to the wound at the time of skin closure in ≥ 80% of patients. Patients were assigned suture or staple skin closure in a sequential, non-randomized fashion. Skin perfusion was recorded using a near-infrared imaging system after ICG injection and measured by video analysis at predefined points before and after skin closure. Clinicodemographic, pre- and intraoperative details, and surgical secondary events were recorded.

Results

Of 20 participants, 10 were assigned staple closure and 10 suture closure. Two patients (10%) achieved objective quantification of ICG fluorescence before and after laparotomy closure, failing the predefined feasibility threshold of ≥ 80%. Reasons for failed quantification included overexposure (12), insufficient ICG signal uptake (6), and insufficient video quality (2). Near-infrared angiography wound perfusion was subjectively appreciated intraoperatively in 85% (17/20) of patients before and after wound closure.

Conclusions

Objective assessment of laparotomy skin closure with near-infrared angiography–measured perfusion did not meet the pre-specified feasibility threshold. Adjustments to the protocol to minimize overexposure may be warranted. The ability to subjectively appreciate ICG perfusion with near-infrared angiography suggests a possible role for near-infrared angiography in the real-time intraoperative assessment of wound perfusion, particularly in high-risk patients.

Perioperative Hyperspectral Imaging to Assess Mastectomy Skin Flap and DIEP Flap Perfusion in Immediate Autologous Breast Reconstruction: A Pilot Study

Mastectomy skin flap necrosis (MSFN) and partial DIEP (deep inferior epigastric artery perforator) flap loss represent two frequently reported complications in immediate autologous breast reconstruction. These complications could be prevented when areas of insufficient tissue perfusion are detected intraoperatively. Hyperspectral imaging (HSI) is a relatively novel, non-invasive imaging technique, which could be used to objectively assess tissue perfusion through analysis of tissue oxygenation patterns (StO₂%), near-infrared (NIR%), tissue hemoglobin (THI%), and tissue water (TWI%) perfusion indices. This prospective clinical pilot study aimed to evaluate the efficacy of HSI for tissue perfusion assessment and to identify a cut-off value for flap necrosis. Ten patients with a mean age of 55.4 years underwent immediate unilateral autologous breast reconstruction. Prior, during and up to 72 h after surgery, a total of 19 hyperspectral images per patient were acquired. MSFN was observed in 3 out of 10 patients. No DIEP flap necrosis was observed. In all MSFN cases, an increased THI% and decreased StO₂%, NIR%, and TWI% were observed when compared to the vital group. StO₂% was found to be the most sensitive parameter to detect MSFN with a statistically significant lower mean StO₂% (51% in the vital group versus 32% in the necrosis group, p < 0.0001) and a cut-off value of 36.29% for flap necrosis. HSI has the potential to accurately assess mastectomy skin flap perfusion and discriminate between vital and necrotic skin flap during the early postoperative period prior to clinical observation. Although the results should be confirmed in future studies, including DIEP flap necrosis specifically, these findings suggest that HSI can aid clinicians in postoperative mastectomy skin flap and DIEP flap monitoring.

The Role of ICG Angiography in Decision Making About Skin-Sparing in Pediatric Acute Trauma

BACKGROUND

Indocyanine green (ICG) angiography has proven useful in assessing skin flap perfusion in plastic and reconstructive surgeries. This research aimed to explore its role in decision making about skin-sparing in children's acute trauma.

METHODS

A total of 19 patients suffering with acute trauma from January 2019 to September 2021 were retrospectively assessed. Both ICG angiography and clinical judgment were performed to evaluate skin tissue viability. The intraoperative decisions for each case depended on the specific condition of the traumatic wound, including tissue perfusion, skin defect area, and location of the wound. Postoperative vascular imaging software was used to quantify the tissue perfusion, and the duration of postoperative follow-up was from 6 to 18 months.

RESULTS

Among them, 18 (94.7%) patients experienced treatments according to ICG angiography and did not develop postoperative necrosis. One case with right forearm trauma suffered from partial necrosis. Hypertrophic scar and local infection were the independent complications, which were managed by symptomatic treatment.

CONCLUSION

ICG angiography may reduce the risk of postoperative necrosis and renders a promising adjunctive technique for surgeons to make reasonable decisions in skin sparing in acute pediatric trauma.

Study protocol for a 10-year prospective observational study, examining lymphoedema and patient-reported outcome after breast reconstruction

INTRODUCTION

Over the last decades, treatment of breast cancer has become increasingly more effective. Consequently, an increasing number of women are living with late effects of breast cancer treatment, including disfiguring scars, deformity or asymmetry of the breast, secondary lymphoedema and other physical and psychosocial late effects. Data from this study will provide knowledge on how to guide breast reconstruction in the future towards outcomes with fewer complications, higher long-term quality of life (QoL) and satisfaction with the aesthetic outcome. The development of secondary lymphoedema, for which the effect of breast reconstruction has yet to be established, will be thoroughly examined.

METHODS AND ANALYSIS

Women receiving breast reconstruction (autologous and implant based) at the Department of Plastic Surgery and Burns Treatment, Rigshospitalet, will be invited to participate. The patients will be followed for 10 years postoperatively. Demographic, health-related, oncological characteristics and treatment data will be registered. Validated assessment tools, such as the BREAST-Q and Beck Depression Inventory, will be used to measure an extensive range of clinical outcomes, including QoL, life and aesthetic satisfaction and depression. Arm range of motion will be measured with a goniometer and lymphoedema by bioimpedance spectroscopy, compared with circular arm measurements.

ETHICS AND DISSEMINATION

This study will be conducted according to the 5th version of the Helsinki Declaration. The regional ethical committee for Capital Region Denmark did not find the study notifiable, according to the law of the committee § 1, part 4. All data will be anonymised before its publication. This study will be conducted according to the Danish data protection regulation and is catalogued and approved by the Capital Region Head of Knowledge Centre. According to the Danish health law § 46, part 2, this study does not need the Danish Patient Safety Authority's approval. The findings of this study will be submitted to international peer-reviewed journals.

Comparison of Various Modalities Utilized for Preoperative Planning in Microsurgical Reconstructive Surgery

BACKGROUND

 The benefits of preoperative perforator imaging for microsurgical reconstruction have been well established in the literature.

METHODS

 An extensive literature review was performed to determine the most commonly used modalities, and their applicability, advantages and disadvantages.

RESULTS

 The review demonstrated varioius findings including decreases in operative time and cost with the use of CT angiography to identification of perforators for inclusion in flap design with hand-held Doppler ultrasound. Modalities like MR angiography offer alternatives for patients with contrast allergies or renal dysfunction while maintaining a high level of clarity and fidelity. Although the use of conventional angiography has decreased due to the availability of less invasive alternatives, it continues to serve a role in the preoperative evaluation of patients for lower extremity reconstruction. Duplex ultrasonography has been of great interest recently as an inexpensive, risk free, and extraordinarily accurate diagnostic tool. Emerging technologies such as indocyanine green fluorescence angiography and dynamic infrared thermography provide real-time information about tissue vascularity and perfusion without requiring radiation exposure.

CONCLUSION

 This article presents an in-depth review of the various imaging modalities available to reconstructive surgeons and includes hand held Doppler ultrasound, CT angiography, MR angiography, conventional angiography, duplex ultrasonography, Indocyanine Green Fluorescence Angiography and Dynamic Infrared Thermography.

Understanding the Evidence and Improving Outcomes with Implant-Based Prepectoral Breast Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the risks, benefits, and safety profile of prepectoral breast reconstruction. 2. Have knowledge of primary immediate and delayed prepectoral breast reconstruction techniques and secondary procedures required. 3. Describe data on outcomes of prepectoral breast reconstruction.

SUMMARY

Once considered to have an unacceptable complication profile, prepectoral breast reconstruction is increasing in popularity because of decreased surgical invasiveness and postoperative pain and the absence of animation deformity. Short-term outcomes studies comparing prepectoral breast reconstruction to partially submuscular techniques demonstrate similarly acceptable rates of postoperative complications. Aesthetic outcomes demonstrate similar rates of capsular contracture but increased rippling and implant palpability of the upper pole. Postoperative functional data are limited but overall show decreased pain and more rapid return of function but equivalent satisfaction on the BREAST-Q. Long-term aesthetic data and rates of revision are lacking.

Periorbital and Perioral Defect Reconstruction Using the Split Pre-Expanded Medial Arm Flap Aided by Using Indocyanine Green Angiography

ABSTRACT

The pre-expanded medial arm flap provides suitable skin for the resurfacing of a periorbital or perioral defect. However, the flap must be intraoperatively split to imitate the appearance of the oral or ophthalmic fissure, which can compromise flap perfusion. This study aimed to evaluate the safety and effectiveness of splitting pre-expanded medial arm flaps with the aid of indocyanine green angiography. All 8 patients underwent periorbital or perioral soft tissue reconstruction using a split pre-expanded medial arm flap. Flap splitting was aided by indocyanine green angiography. It was used during 2 stages of the procedure, tissue expander placement and flap transfer. The pedicle was divided 3 weeks later, and the flaps were used to resurface the defect. The distal portion of the flap was split into a fishmouth pattern in 5 patients and a window pattern in 3 patients. The donor sites were closed directly or by using a latissimus dorsi myocutaneous flap. There were no perioperative complications or flap necrosis. A pre-expanded split medial arm flap could be an option for the reconstruction of periorbital and perioral defects. With the assistance of indocyanine green angiography, vessel distribution and distal flap perfusion can be reliably evaluated, facilitating the safe splitting of the flap for the reconstruction of defects.

Indocyanine Green Fluorescence in Colorectal Cancer

Fluorescence vision using indocyanine green is a surgical tool with increasing applications in colorectal cancer surgery. This tool has received acceptance in several disciplines as a potential method to improve visualization of the surgical field, improve lymph node resection and decrease the incidence of anastomotic leaks (ALs). In colorectal surgery specifically, some studies have shown that intraoperative fluorescence imaging is a safe and feasible method to evaluate anastomotic perfusion, and its use could affect the incidence of anastomotic leaks. Currently, controlled trials are carried out to validate these conclusions, as well as new indications for indocyanine green such as detection and guidance in the management of hepatic colorectal metastases, visualization of ureters and even as tumor marking and improvement the lymph node harvest of early tumors. These advances could offer great value to surgeons and patients, by improving the accuracy and results of cancer resections.

Safety Profile and Predictors of Aesthetic Outcomes After Prepectoral Breast Reconstruction With Meshed Acellular Dermal Matrix

INTRODUCTION

Prepectoral acellular dermal matrix (ADM)-assisted breast reconstruction has demonstrated improved pain scores, faster return to full range of motion, and an appropriate postoperative safety profile when compared with cohorts with submuscular implant placement; however, there are limited data on aesthetic outcomes. Basic science biointegration research has previously demonstrated faster ADM incorporation with fenestrated compared with confluent ADM. We report the safety profile of anterior support meshed ADM prepectoral breast reconstruction and analyze predictive factors for aesthetic outcomes after gel implant placement.

METHODS

All consecutive immediate staged prepectoral expander-to-implant breast reconstructions with more than 6 months of follow-up were compared with a partially submuscular cohort for demographics, comorbidities, and postoperative complications. All patients 1 to 3.5 years after gel implant placement were evaluated for the impact of clinical characteristics on aesthetic outcomes.

RESULTS

Two hundred twenty-four prepectoral tissue expander placements were compared with 535 partially submuscular tissue expanders with no significant differences in demographics. There was increased wound dehiscence repaired in clinic and insignificantly decreased seromas with prepectoral expander placement. One hundred sixty breasts were reconstructed with gel implants, and 12 underwent autologous reconstruction during the conduct of the study. The remaining 21 patients were continuing expansion, and 3 succumbed to disease progression. Regression analysis of 86 breast reconstructions showed that a body mass index of greater than 30, fat grafting, and highly cohesive anatomic implants decreased rippling, whereas radiation increased capsular contracture (P < 0.05).

CONCLUSIONS

Prepectoral meshed ADM breast reconstruction has an equivalent safety profile to partially submuscular ADM-assisted reconstruction and early aesthetic ratings comparable with other published accounts of implant-based reconstruction. Radiated skin envelopes carry higher capsular contracture rates. Thin patients have a higher risk of visible rippling, whereas fat grafting and higher cohesivity implants are associated with less rippling.

A Systematic Review of the Utility of Indocyanine Angiography in Autologous Breast Reconstruction

BACKGROUND

In the last decade, a number of studies have demonstrated the utility of indocyanine green (ICG) angiography in predicting mastectomy skin flap necrosis for immediate breast reconstruction. However, data are limited to investigate this technique for autologous breast reconstruction. Although it may have the potential to improve free flap outcomes, there has not been a large multicenter study to date that specifically addresses this application.

METHODS

A thorough literature review based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines was conducted. All studies that examined the use of intraoperative ICG angiography or SPY to assess perfusion of abdominally based free flaps for breast reconstruction from January 1, 2000, to January 1, 2020, were included. Free flap postoperative complications including total flap loss, partial flap loss, and fat necrosis were extracted from selected studies.

RESULTS

Nine relevant articles were identified, which included 355 patients and 824 free flaps. A total of 472 free flaps underwent clinical assessment of perfusion intraoperatively, whereas 352 free flaps were assessed with ICG angiography. Follow-up was from 3 months to 1 year. The use of ICG angiography was associated with a statistically significant decrease in flap fat necrosis in the follow-up period (odds ratio = 0.31, P = 0.02). There was no statistically significant difference for total or partial flap loss.

CONCLUSIONS

From this systematic review, it can be concluded that ICG angiography may be an effective and efficient way to reduce fat necrosis in free flap breast reconstruction and may be a more sensitive predictor of flap perfusion than clinical assessment alone. Future prospective studies are required to further determine whether ICG angiography may be superior to clinical assessment in predicting free flap outcomes.

Use of Indocyanine Green Angiography decreases the risk of complications in autologous- and implant-based breast reconstruction: A systematic review and meta-analysis

INTRODUCTION

Indocyanine Green Angiography (ICG-A) is an imaging technique used to visualize tissue perfusion in real time. The aim of this systematic review and meta-analysis is to evaluate all published papers on breast reconstruction using ICG-A, which provides information on complication rates and to investigate whether the use of this peroperative method decreases the risk of complications.

MATERIALS AND METHODS

MEDLINE/PubMed, EMBASE, Cochrane, and UpToDate were searched using relevant terms. The literature was assessed using the PRISMA guidelines. Inclusion criteria were: original articles written in English assessing ICG-angiography in breast reconstruction. The individual studies were evaluated according to Cochrane guidelines.

RESULTS

The search yielded 243 papers on ICG-A and breast reconstruction. Twenty-six of these were included for analysis. The risk of overall major complications ([OR] = 0.53, 95% confidence interval (CI) = 0.43-0.66, p = 0.00001) and overall loss of reconstruction ([OR] = 0.58, 95% CI = 0.37-0.92, and p = 0.020) was significantly lower when peroperative ICG-A was used. When using ICG-A to evaluate mastectomy flaps, a statistically lower risk of major complications ([OR] = 0.56 and p = 0.0001) and the loss of reconstruction was found ([OR] = 0.46, p = 0.006). ICG-A used in autologous breast reconstruction significantly reduced the risk of minor ([OR] = 0.62 and p = 0.001) and major complications ([OR] = 0.53 and p = 0.0028).

CONCLUSIONS

This is the first systematic review to analyze the use of ICG-A on both mastectomy flaps and autologous reconstruction. The results obtained in the current study indicate that the use of ICG-A in breast reconstructive procedures reduces the complications as well as the loss of reconstruction.

Use of Indocyanine Green Angiography for Real-Time Assessment of a Sternocleidomastoid Muscle Flap During Complex Facial Reconstruction

Indocyanine green (ICG) angiography is a procedure that uses a fluorescent dye for a variety of medical diagnostics, including the real-time examination of blood flow in tissue. Herein, we report a case in which ICG angiography was used to assess the viability of a sternocleidomastoid (SCM) muscle flap during post-parotidectomy facial reconstruction. To our knowledge, this is the first report documenting the intraoperative use of ICG for the evaluation of SCM flap perfusion. ICG angiography may prove beneficial for cases involving complex reconstructions and suspected organ hypoperfusion.

Alternative flaps in autologous breast reconstruction

The gold standard for autologous reconstruction in the post-mastectomy patient remains the deep inferior epigastric artery perforator flap, although many women may not be candidates for abdominally based free tissue transfer. In this scenario, there are several other donor site options based from the thigh (transverse and diagonal upper gracilis flaps, profunda artery perforator flap, lateral thigh flap) and trunk (lumbar artery perforator flap, superior and inferior gluteal artery perforator flaps). This study will review the history, relevant anatomy, surgical technique and outcomes for alternative flaps in autologous reconstruction. Additionally, preoperative imaging (CTA, MRA) and novel applications (stacking flaps, neurotization) in breast reconstructive microsurgery will be discussed.

Indocyanine Green Angiography Predicts Tissue Necrosis More Accurately Than Thermal Imaging and Near-Infrared Spectroscopy in a Rat Perforator Flap Model

BACKGROUND

Clinical examination alone is neither sensitive nor specific for predicting flap necrosis, so several technologies, including indocyanine green angiography, thermal imaging (using the FLIR ONE), and near-infrared spectroscopy, have been developed to supplement perfusion assessment. This study aims to compare the accuracy of these three methods for intraoperatively predicting clinical flap necrosis in a rat perforator flap model. The authors hypothesized that near-infrared spectroscopy, assessing oxygenation rather than direct perfusion, would yield significantly different predictions.

METHODS

A 10 × 3-cm epigastric perforator flap was elevated in 14 adult male rats weighing 250 ± 50 g. Flap perfusion was assessed immediately after flap elevation using thermal imaging, near-infrared spectroscopy, and indocyanine green angiography. Measurements were correlated to the clinical endpoint and gold standard of flap necrosis on postoperative day 7.

RESULTS

All three technologies detected significant differences in perfusion along flap length (all p < 0.001), and were associated with significant differences in the odds of developing flap necrosis (all p < 0.001). The areas under the receiver operating characteristic curves were 0.948 for indocyanine green angiography as an absolute value, 0.873 for relative changes with thermal imaging, and 0.792 for tissue oxygenation. The sensitivity, specificity, and accuracy for indocyanine green angiography measured as an absolute value were the highest at 97.8, 87.5, and 92 percent, respectively.

CONCLUSIONS

Indocyanine green angiography most accurately predicted flap necrosis in this study; however, tissue oximetry and thermal imaging were also capable of predicting necrosis and represented potentially less expensive or more readily available alternatives for objective perfusion assessment. Additional research can further delineate their roles and cost-efficacy in clinical practice.

Optimizing the Mastectomy Flap to Improve Aesthetic Outcomes

The aesthetics of breast reconstruction inherently rely on both the ablative and reconstructive procedures. Mastectomy flap quality remains one of the most critical factors in determining the success of a reconstruction and its aesthetic outcome. Maintaining the segmental perfusion to the nipple and skin envelope during mastectomy requires preserving the subcutaneous tissue superficial to the breast capsule. Because this layer of tissue varies in thickness among different patients and within each breast, anatomic dissection along the appropriate planes is required rather than a "one-size-fits-all" mentality. A team-based approach between the breast surgeon and plastic surgeon will optimize both the ablative and reconstructive procedures while engaging in a process of shared decision-making with the patient. Preoperative clinical analysis and utilization of imaging to assess individual breast anatomy will help guide mastectomies as well as decisions on reconstructive modalities. Critical assessment of mastectomy flaps is paramount and requires flexibility to adapt reconstructive paradigms intraoperatively to minimize the risk of complications and provide the best aesthetic result.

Intraoperative fluorescence perfusion assessment should be corrected by a measured subject-specific arterial input function

SIGNIFICANCE

The effects of varying the indocyanine green injection dose, injection rate, physiologic dispersion of dye, and intravenous tubing volume propagate into the shape and magnitude of the arterial input function (AIF) during intraoperative fluorescence perfusion assessment, thereby altering the observed kinetics of the fluorescence images in vivo.

AIM

Numerical simulations are used to demonstrate the effect of AIF on metrics derived from tissue concentration curves such as peak fluorescence, time-to-peak (TTP), and egress slope.

APPROACH

Forward models of tissue concentration were produced by convolving simulated AIFs with the adiabatic approximation to the tissue homogeneity model using input parameters representing six different tissue examples (normal brain, glioma, normal skin, ischemic skin, normal bone, and osteonecrosis).

RESULTS

The results show that AIF perturbations result in variations in estimates of total intensity of up to 80% and TTP error of up to 200%, with the errors more dominant in brain, less in skin, and less in bone. Interestingly, error in ingress slope was as high as 60% across all tissue types. These are key observable parameters used in fluorescence imaging either implicitly by viewing the image or explicitly through intensity fitting algorithms. Correcting by deconvolving the image with a measured subject-specific AIF provides an intuitive means of visualizing the data while also removing the source of variance and allowing intra- and intersubject comparisons.

CONCLUSIONS

These results suggest that intraoperative fluorescence perfusion assessment should be corrected by patient-specific AIFs measured by pulse dye densitometry.

Snapshot Multispectral Imaging Is Not Inferior to SPY Laser Fluorescence Imaging When Predicting Murine Flap Necrosis

BACKGROUND

Objective assessment of tissue viability is critical to improve outcomes of cosmetic and reconstructive procedures. A widely used method to predict tissue viability is indocyanine green angiography. The authors present an alternative method that determines the relative proportions of oxyhemoglobin to deoxyhemoglobin through multispectral reflectance imaging. This affordable, hand-held device is noninvasive and may be used in clinic settings. The authors hypothesize that multispectral reflectance imaging is not inferior to indocyanine green angiography in predicting flap necrosis in the murine model.

METHODS

Reverse McFarlane skin flaps measuring 10 × 3 cm were raised on 300- to 400-g male Sprague-Dawley rats. Indocyanine green angiography and multispectral reflectance imaging was performed before surgery, immediately after surgery, and 30 minutes after surgery. Clinical outcome images acquired 72 hours after surgery were evaluated by three independent plastic surgeons. Objective data obtained immediately after surgery were compared to postsurgical clinical outcomes to determine which method more accurately predicted flap necrosis.

RESULTS

Nine reverse McFarlane skin flaps were evaluated 72 hours after flap elevation. Data analysis demonstrated that the 95 percent confidence intervals for the sensitivity of postoperative multispectral reflectance imaging and indocyanine green angiography imaging to predict 72-hour tissue viability at a fixed specificity of 90 percent for predicting tissue necrosis were 86.3 to 91.0 and 79.1 to 86.9, respectively.

CONCLUSIONS

In this experimental animal model, multispectral reflectance imaging does not appear to be inferior to indocyanine green angiography in detecting compromised tissue viability. With the advantages of noninvasiveness, portability, affordability, and lack of disposables, multispectral reflectance imaging has an exciting potential for widespread use in cosmetic and reconstructive procedures.

Intraoperative indocyanine green fluorescence imaging in breast surgery

Background

Since postoperative complications after reconstructive breast surgery are often related to drastic increases of patient suffering and treatment costs, several devices were developed in order to avoid them. In this respect, the intraoperative fluorescence angiography with indocyanine green (ICG) provides promising results by detecting ischemic skin intraoperatively.

Methods

Women who underwent reconstructive breast surgery at the breast center at Charité between April and December 2017 were included in the analysis. General patient characteristics, medical history, type of surgery, as well as postoperative parameters, complications and patient reported outcomes were compared between patients operated using ICG fluorescence angiography and conventionally operated patients.

Results

Among 68 patients with breast reconstruction 36 (52.9%) were operated with the ICG angiography device and 32 (47.1%) without. No significant differences regarding patient demographics, medical history, and surgical procedure were found. Wound healing disorders occurred in 11.1% of the ICG group and in 9.4% of the control group. About 11% of both groups developed major complications which required revision surgery. Complication rates and patient reported outcome did not differ significantly. Across both groups, only the risk factor resection weight (≥ 500 g) was significantly associated with wound healing disorders (RR = 6.80; 95%CI 1.93–23.81; p = 0.022).

Conclusion

The purchase of a device for intraoperative ICG angiography might not be reasonable for every breast center. Further research in a larger cohort and prospective manner should be done to determine if the addition of ICG to breast reconstructive surgery in the German setting really leads to improved patient care.

Indocyanine green angiography for preventing postoperative mastectomy skin flap necrosis in immediate breast reconstruction

BACKGROUND

Breast cancer will affect one in eight women during their lifetime. The opportunity to restore the removed tissue and cosmetic appearance is provided by reconstructive breast surgery following skin-sparing mastectomy (SSM). Mastectomy skin flap necrosis (MSFN) is a common complication following SSM breast reconstruction. This postoperative complication can be prevented by intraoperative assessment of mastectomy skin flap viability and intervention when tissue perfusion is compromised. Indocyanine green fluorescence angiography is presumed to be a better predictor of MSFN compared to clinical evaluation alone.

OBJECTIVES

To assess the effects of indocyanine green fluorescence angiography (ICGA) for preventing mastectomy skin flap necrosis in women undergoing immediate breast reconstruction following skin-sparing mastectomy. To summarise the different ICGA protocols available for assessment of mastectomy skin flap perfusion in women undergoing immediate breast reconstructions following skin-sparing mastectomy.

SEARCH METHODS

We searched the Cochrane Breast Cancer Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL; Issue 3, 2019), MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform (ICTRP) and Clinicaltrials.gov in April 2019. In addition, we searched reference lists of published studies.

SELECTION CRITERIA

We included studies that compared the use of ICGA to clinical evaluation to assess mastectomy skin vascularisation and recruited women undergoing immediate autologous or prosthetic reconstructive surgery following SSM for confirmed breast malignancy or high risk of developing breast cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias of the included nonrandomised studies and extracted data on postoperative outcomes, including postoperative MSFN, reoperation, autologous flap necrosis, dehiscence, infection, haematoma and seroma, and patient-related outcomes. The quality of the evidence was assessed using the GRADE approach and we constructed two 'Summary of finding's tables: one for the comparison of ICGA to clinical evaluation on a per patient basis and one on a per breast basis.

MAIN RESULTS

Nine nonrandomised cohort studies met the inclusion criteria and involved a total of 1589 women with 2199 breast reconstructions. We included seven retrospective and two prospective cohort studies. Six studies reported the number of MSFN on a per breast basis for a total of 1435 breasts and three studies reported the number of MSFN on a per patient basis for a total of 573 women. Five studies reported the number of other complications on a per breast basis for a total of 1370 breasts and four studies reported the number on a per patient basis for a total of 613 patients. Therefore, we decided to pool data separately. Risk of bias for each included nonrandomised study was assessed using the Newcastle-Ottawa Scale for cohort studies. There was serious concern with risk of bias due to the nonrandomised study design of all included studies and the low comparability of cohorts in most studies. The quality of the evidence was found to be very low, after downgrading the quality of evidence twice for imprecision based on the small sample sizes and low number of events in the included studies. Postoperative complications on a per patient basis We are uncertain about the effect of ICGA on MSFN (RR 0.79, 95% CI 0.40 to 1.56; three studies, 573 participants: very low quality of evidence), infection rates (RR 0.91, 95% CI 0.60 to 1.40; four studies, 613 participants: very low quality of evidence), haematoma rates (RR 0.87, 95% CI 0.30 to 2.53; two studies, 459 participants: very low quality of evidence) and seroma rates (RR 1.68, 95% CI 0.41 to 6.80; two studies, 408 participants: very low quality of evidence) compared to the clinical group. We found evidence that ICGA may reduce reoperation rates (RR 0.50, 95% CI 0.35 to 0.72; four studies, 613 participants: very low quality of evidence). One study considered dehiscence as an outcome. In this single study, dehiscence was observed in 2.2% of participants (4/184) in the ICGA group compared to 0.5% of participants (1/184) in the clinical group (P = 0.372). The RR was 4.00 (95% CI 0.45 to 35.45; one study; 368 participants; very low quality of evidence). Postoperative complications on a per breast basis We found evidence that ICGA may reduce MSFN (RR 0.62, 95% CI 0.48 to 0.82; six studies, 1435 breasts: very low quality of evidence), may reduce reoperation rates (RR 0.65, 95% CI 0.47 to 0.92; five studies, 1370 breasts: very low quality of evidence) and may reduce infection rates (RR 0.65, 95% CI 0.44 to 0.97; five studies, 1370 breasts: very low quality of evidence) compared to the clinical group. We are uncertain about the effect of ICGA on haematoma rates (RR 1.53, CI 95% 0.47 to 4.95; four studies, 1042 breasts: very low quality of evidence) and seroma rates (RR 0.71, 95% CI 0.37 to 1.35; two studies, 528 breasts: very low quality of evidence). None of the studies reported patient-related outcomes. ICGA protocols: eight studies used the SPY System and one study used the Photodynamic Eye imaging system (PDE) to assess MSFN. ICGA protocols in the included studies were not extensively described in most studies.

AUTHORS' CONCLUSIONS

Although mastectomy skin flap perfusion is performed more frequently using ICGA as a helpful tool, there is a lack of high-quality evidence in the context of randomised controlled trials. The quality of evidence in this review is very low, since only nonrandomised cohort studies have been included. With the results from this review, no conclusions can be drawn about what method of assessment is best to use during breast reconstructive surgery. High-quality randomised controlled studies that compare the use of ICGA to assess MSFN compared to clinical evaluation are needed.