Predictors and consequences of intraoperative microvascular problems in autologous breast reconstruction

Risk-Stratified Anticoagulation Protocol Increases Success of Lower Extremity Free Tissue Transfer in the Setting of Thrombophilia

BACKGROUND

Optimal perioperative thromboprophylaxis is crucial to avoid flap thrombosis and achieve high rates of microsurgical success. At the authors' institution, implementation of a risk-stratified anticoagulation (AC) protocol preliminarily showed a reduction in postoperative thrombotic events and flap loss. The authors present an updated analysis of surgical outcomes using risk-stratified AC in thrombophilic patients who underwent free tissue transfer (FTT) reconstruction for nontraumatic lower extremity (LE) wounds.

METHODS

The authors retrospectively reviewed patients who underwent FTT to an LE from 2012 to 2021. Their risk-stratification AC protocol was implemented in July of 2015. Low-risk and moderate-risk patients received subcutaneous heparin. High-risk patients received heparin infusion titrated to a goal partial thromboplastin time of 50 to 70 seconds. Before July of 2015, nonstratified patients were treated with either subcutaneous heparin or low-dose heparin infusion (500 U/hour). Patients were divided into two cohorts (nonstratified and risk-stratified) based on date of FTT reconstruction. Primary outcomes included rates of postoperative complications, flap salvage, and flap success.

RESULTS

Two hundred nineteen hypercoagulable patients who underwent FTT to an LE were treated with nonstratified ( n = 26) or risk-stratified ( n = 193) thromboprophylaxis. The overall flap success rate was 96.8% ( n = 212). Flap loss was lower among risk-stratified patients (1.6% versus 15.4%; P = 0.004), which paralleled a significant reduction in postoperative thrombotic events (2.6% versus 15.4%; P = 0.013). Flap salvage was accomplished more often in the risk-stratified cohort (80% versus 0%; P = 0.048). Intraoperative anastomotic revision (OR, 6.10; P = 0.035) and nonrisk stratification (OR, 9.50; P = 0.006) were independently associated with flap failure.

CONCLUSIONS

Hypercoagulability can significantly affect microsurgical outcomes. Implementation of a risk-stratified AC protocol can significantly improve flap outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Intraoperative vasopressor use does not increase complications in microvascular post-mastectomy breast reconstruction: Experience in 1729 DIEP flaps at a single center

INTRODUCTION

Vasopressors are traditionally avoided in microsurgery due to concerns about their effect on free flap survival. We examine the impact of intraoperative vasopressors on microsurgical outcomes in a large series of DIEP flap breast reconstructions.

METHODS

A retrospective chart review was performed of patients who underwent DIEP breast reconstruction between January 2010 and May 2020. Intraoperative and postoperative microsurgical outcomes were compared in patients who received vasopressors and those who did not.

RESULTS

The study included 1102 women who underwent 1729 DIEP. 878 patients (79.7%) received intraoperative phenylephrine, ephedrine, or a combination of both. There was no significant difference in overall complications, intraoperative microvascular events, takebacks for microvascular complications, or partial or total flap loss between groups. Outcomes were not affected by vasopressor type, dose, or timing of administration. The vasopressor group received significantly lower intraoperative fluid volumes. Multivariate logistic regression found a significant association between overall complications and excessive fluids (OR 2.03, 99% CI 0.98-5.18, p = 0.03) but not vasopressor use (OR 0.79, 99% CI 0.64-3.16, p = 0.7) CONCLUSION: This study demonstrates that vasopressors do not adversely affect clinical outcomes after DIEP breast reconstruction. Withholding vasopressors results in excessive intravenous fluid administration and increased postoperative complications.

Preoperative Assessment of the Breast Reconstruction Patient

Through a multidisciplinary approach, as well as, a nuanced appreciation of patient goals and setting appropriate expectations, breast reconstruction can significantly improve the quality of life following mastectomy. A thorough review of the patient medical and surgical history in addition to oncologic treatments will facilitate discussion and recommendations for an individualized shared decision-making reconstructive process. Alloplastic reconstruction, although a highly popular modality, has important limitations. On the contrary, autologous reconstruction is more flexible but requires more thorough consideration.

Breast Reconstruction: Necessity for Further Standardization of the Current Surgical Techniques Attempting to Facilitate Scientific Evaluation and Select Tailored Individualized Procedures Optimizing Patient Satisfaction

Background

Various breast cancer reconstruction methods and novel surgical techniques include autologous or allogenic procedures, which can increase patient's quality of life and provide options when dealing with patients seen as challenging clinical scenarios.

Summary

Our aim was to review the current literature and present published evidence on innovative standards in whole breast reconstruction. Advances in flap monitoring or newly published data regarding neurotization in breast reconstruction, arm lymphedema management, breast implant-associated anaplastic large cell lymphoma reconstruction treatment, and robotic surgery with regard to radiotherapy define innovative standards in the breast reconstruction setting. The role of meshes/acellular dermal matrix and fat grafting as well as optimal sequencing of postmastectomy radiotherapy in autologous and alloplastic breast reconstruction appear highly debatable also in expert panel meetings rendering further clinical research including RCTs imperative.

Key Messages

There is an abundance of novel available techniques, which mandate further standardization, facilitating scientific evaluation in an attempt to help surgeons select tailored procedures for each patient with the goal to promote informed decision-making in breast reconstruction.

Uni-vs. bilateral DIEP flap reconstruction - A multicenter outcome analysis

OBJECTIVE

Over the past decade numbers of bilateral mastectomy have increased steadily. As a result, bilateral breast reconstruction is gaining popularity. The presented study compares complications and outcomes of unilateral and bilateral DIEP free-flap breast reconstructions using the largest database available in Europe.

METHODS

Female breast cancer patients (n = 3926) receiving DIEP flap breast reconstructions (n = 4577 free flaps) at 22 different centers were included in this study. Free flaps were stratified into two groups: a unilateral- (UL) and a bilateral- (BL) breast reconstruction group. Groups were compared with regard to surgical complications and free flap outcome.

RESULTS

Mean operative time was significantly longer in the BL group (UL: 285.2 ± 107.7 vs. BL: 399.1 ± 136.8 min; p < 0.001). Mean ischemia time was comparable between groups (p = 0.741). There was no significant difference with regard to total (UL 1.8% vs. BL 2.6%, p = 0.081) or partial flap loss (UL 1.2% vs. BL 0.9%, p = 0.45) between both groups. Rates of venous or arterial thrombosis were comparable between both groups (venous: UL 2.9% vs. BL 2.2%, p = 0.189; arterial: UL 1.8% vs. BL 1.2%, p = 0.182). However, significantly higher rates of hematoma at the donor and recipient site were observed in the UL group (donor site: UL 1.1% vs. BL 0.1%, p = 0.001; recipient site UL 3.9% vs. BL 1.7%, p < 0.001).

CONCLUSIONS

The data underline the feasibility of bilateral DIEP flap reconstruction, when performed in a setting of specialized centers.

Latest Advancements in Autologous Breast Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the available donor sites for autologous breast reconstruction. 2. Describe the advantages and limitations of each donor site. 3. Provide a rational, algorithmic preoperative evaluation and approach for patients seeking autologous breast reconstruction. 4. Develop an effective postoperative monitoring system to minimize complications and maximize salvage of microvascular thromboses.

SUMMARY

Breast reconstruction remains at the heart of the field of plastic and reconstructive surgery, and it is continuously evolving. Tremendous advances in breast implant technology and supplemental products, particularly acellular dermal matrices, have revolutionized breast reconstruction in the modern era. However, microvascular free flap breast reconstruction has also witnessed profound advancements with exceptionally high success rates, with the ability to provide the most durable and natural breast reconstruction. Although the pendulum oscillates between prosthesis-based reconstruction and autologous tissue, the present synopsis will focus on autologous free flap breast reconstruction from an historical perspective, recent advancements in microsurgery, and the future of autologous breast reconstruction.

Predicting risk factors that lead to free flap failure and vascular compromise: A single unit experience with 565 free tissue transfers

BACKGROUND

Even though the benefit of free tissue transfer is uncontested in complex reconstructive cases, vascular compromise and/or flap failure remain a challenge for the surgeon and identification of possible risk factors can aid in the preoperative planning. The aim of this study was to identify the individual risk factors leading to flap failure and/or vascular compromise in free tissue transfers in a single institution over a period of 10 years and to create an index predicting these problems, as well as finding predictors of other postoperative complications.

METHODS

Data from all the patients undergoing free tissue transfers between 2009 and 2018 were retrospectively analyzed (demographics, comorbidities, flap failure, vascular compromise, and other complications). The results from the univariate and multivariate analyses were used to create an index.

RESULTS

A predictability index with three classes (low, moderate, and high risk) was calculated for each patient, based on defect etiology and the presence of coronary heart disease, diabetes, smoking, peripheral arterial vascular disease, and arterial hypertension. A patient with moderate-risk index had 9.3 times higher chances of developing vascular compromise than those in the low-risk group, while a high-risk index had 18.6 higher odds (p=0.001). American Society of Anesthesiologists (ASA) classification was found to be a predictor of complications in free tissue transfer (p=0.001).

CONCLUSION

If patients at a high risk of vascular compromise could be identified preoperatively through this predictability index, patient counseling could be improved and the surgeon might adapt the reconstructive plan and choose an alternative reconstructive strategy.

Development and Evaluation of a Machine Learning Prediction Model for Flap Failure in Microvascular Breast Reconstruction

BACKGROUND

Despite high success rates, flap failure remains an inherent risk in microvascular breast reconstruction. Identifying patients who are at high risk for flap failure would enable us to recommend alternative reconstructive techniques. However, as flap failure is a rare event, identification of risk factors is statistically challenging. Machine learning is a form of artificial intelligence that automates analytical model building. It has been proposed that machine learning can build superior prediction models when the outcome of interest is rare.

METHODS

In this study we evaluate machine learning resampling and decision-tree classification models for the prediction of flap failure in a large retrospective cohort of microvascular breast reconstructions.

RESULTS

A total of 1012 patients were included in the study. Twelve patients (1.1%) experienced flap failure. The ROSE informed oversampling technique and decision-tree classification resulted in a strong prediction model (AUC 0.95) with high sensitivity and specificity. In the testing cohort, the model maintained acceptable specificity and predictive power (AUC 0.67), but sensitivity was reduced. The model identified four high-risk patient groups. Obesity, comorbidities and smoking were found to contribute to flap loss. The flap failure rate in high-risk patients was 7.8% compared with 0.44% in the low-risk cohort (p = 0.001).

CONCLUSIONS

This machine-learning risk prediction model suggests that flap failure may not be a random event. The algorithm indicates that flap failure is multifactorial and identifies a number of potential contributing factors that warrant further investigation.

Synergistic Interaction Increases Complication Rates following Microvascular Breast Reconstruction

BACKGROUND

Microvascular breast reconstruction is a complex procedure that can be associated with high complication rates. Although a number of individual predictors of perioperative complications have been identified, few studies have explored interaction between risk factors. Understanding the synergistic effects of multiple risk factors is central to accurate and personalized preoperative risk prediction.

METHODS

The authors conducted a retrospective cohort study of patients who underwent microvascular breast reconstruction at their institution between 2009 and 2017. All intraoperative and postoperative complications were recorded. A multivariable logistic regression exploratory model identified independent predictors of complications. Interactions between individual variables were then assessed using the relative excess risk index (RERI) and the synergy index (SI).

RESULTS

Nine hundred twelve patients were included in the study and 26.1 percent experienced at least one perioperative complication. Obesity (OR, 1.54; p = 0.009), immediate reconstruction (OR, 1.49; p = 0.028), and comorbidities (OR, 1.43; p = 0.033) were identified as independent predictors of complications. Obesity and comorbidities had significant synergistic interactions with immediate reconstruction (RERI, 0.86; SI, 2.35; p = 0.0002; and RERI, 0.54; SI, 1.78; p = 0.001), bilateral reconstruction (RERI, 0.12; SI, 1.15; p = 0.002; and RERI, 0.59; SI, 3.16; p = 0.005), and previous radiotherapy (RERI, 0.62; SI, 4.43; p = 0.01; and RERI, 0.11; SI, 1.23; p = 0.040). Patients undergoing immediate breast reconstruction who were both obese and smokers had a 12-fold increase in complication rates (OR, 12.68; 95 percent CI, 1.36 to 118.46; p = 0.026) with a very strong synergistic interaction between variables (RERI, 10.55; SI, 10.33).

CONCLUSION

Patient- and treatment-related variables interact in a synergistic manner to increase the risk of complications following microvascular breast reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

[Surgical revision in case of DIEP failure in breast reconstruction]

INTRODUCTION

Immediate or delayed breast reconstruction by deep inferior epigastric perforant flap (DIEP) is a frequent and widespread autologous breast reconstruction technique that presents a risk of failure inherent in its microsurgical nature. The main objective was to evaluate the interest of surgical revision in case of DIEP failure, the secondary objective was to evaluate the consequences of surgical revision on the subsequent management.

MATERIALS AND METHODS

This is a retrospective monocentric and single-operator analytical study of 167 unilateral DIEPs carried out from 2008 to 2016. Two groups were compared: success of DIEP without revision versus DIEP requiring a revision that resulted in success or failure. After analyzing the failure and recovery rates of DIEP, we compared the transfusion rate, total operating time, hospitalization time, and final breast reconstruction in the two groups.

RESULTS

One hundred and sixty-seven DIEPs were performed from 2008 to 2016 in 167 women, 18 revisions were reported (10.7%), 12 revisions were successfully reported (7.2%) 6 failures were reported after revision (3.6%). Surgical revision allows the flap to be rescued in 67% of cases. Revision increases the risk of blood transfusion by a factor of 12 (OR=12.24 [95% CI=3.74-43.17] P<0.05). Revision or failure doubles the total operating time (281.8min [170-570] vs. 577.8min [285-860] P<0.05) and increases hospitalization time by 2.5days compared to DIEP's initial success (5.74days [4-9] vs. 8.33days [5-17] P<0.05). Fifty percent of patients choose another type of breast reconstruction after DIEP failure.

CONCLUSION

DIEP is a reliable microsurgical breast reconstruction technique, failure can be prevented in two thirds of cases by monitoring and early reoperation.

Predicting complications in immediate microvascular breast reconstruction: Validity of the breast reconstruction assessment (BRA) surgical risk calculator

BACKGROUND

The Breast Reconstruction Assessment (BRA)-score is a disease-specific risk calculator that estimates the likelihood of postoperative complications in an individual patient. The tool has not been previously externally validated in microvascular breast reconstruction. The purpose of this study was to evaluate the efficacy of the calculator in patients who underwent microvascular reconstruction at a single specialist institution.

METHODS

Data from 415 patients who had immediate microvascular breast reconstruction were entered into the calculator. The predicted and observed rates of surgical complications, medical complications, reoperation, and total or partial flap failure were compared. The accuracy of the calculator was assessed using statistical measures of calibration and discrimination.

RESULTS

The calculator accurately predicted the proportion of patients who would experience surgical complications and reoperations but overestimated the rates of medical complications and flap failures. The C-statistics were low for all four prediction models (0.49-0.59), suggesting weak discriminatory power, and the Brier scores were relatively high (0.09-0.44), indicating poor correlation between predicted and actual probability of complications.

CONCLUSION

These results suggest that the BRA score cannot accurately identify patients at risk for complications following immediate microvascular breast reconstruction at our institution.

Design, implementation, and evaluation of an intervention to improve referral to smoking cessation services in breast cancer patients

PURPOSE

Smoking is a risk factor for poor outcomes following breast reconstructive surgery. This project aimed to design and implement an intervention to consistently refer all breast cancer patients to tobacco treatment services.

METHODS

In formative work, a set of processes for providers to consistently refer patients to a tobacco treatment specialist at the Nicotine Dependence Center (NDC) was designed. Elements included consistent documentation of smoking status, provider advice specific to the benefits of quitting to cancer care, referral to NDC using an "opt-out" strategy that emphasized smoking cessation as a standard part of breast cancer treatment, and reinforcement of the importance of the referral by multiple personnel. The number of referrals to the NDC and number of patients who attended their scheduled NDC appointment were measured before and 1 year after implementation. Qualitative evaluation was performed using semi-structured interviews with participating providers and patients regarding acceptability.

RESULTS

The proportion of smoking patients referred to the NDC increased from 29% (22/75) before the intervention to 74% (20/27) afterward. Among those referred, attendance at the consultation increased from 41% (9/22) to 75% (15/20). This occurred despite provider interviews revealing knowledge gaps about the referral process and evidence of provider adaptation to accommodate personal practice. Feasibility and acceptability of the intervention were high.

CONCLUSION

These findings suggest that similar referral interventions for all cancer patients should be pursued with the aim of embedding tobacco dependence treatment seamlessly and consistently into the cancer treatment plan of every patient who smokes cigarettes.