Impact of Body Mass Index (BMI) on perioperative outcomes following minimally invasive retromuscular abdominal wall reconstruction: a comparative analysis

Background: Morbidity and recurrence rates are higher in obese patients undergoing open abdominal wall reconstruction (AWR). Historically, body mass index (BMI) ≥ 40 has served as a relative contraindication to open AWR. The purpose of this study is to evaluate the impact of minimally invasive surgery (MIS) on outcomes after AWR for higher versus lower BMI patients. Methods: A retrospective review of a prospectively maintained database was conducted of all patients who underwent MIS AWR between September 2015 and April 2019 at our institution. Patients were subdivided into two groups based on their BMI: BMI ≤ 35 kg/m² and BMI > 35 kg/m². Patient demographics and perioperative data were evaluated using univariate and multivariate analysis. Results: 461 patients were identified and divided into two groups: BMI ≤ 35 (n = 310) and BMI > 35 (n = 151). The two groups were similar in age (BMI ≤ 35: 56.3 ± 14.1 years vs. BMI > 35: 54.4 ± 11.9, p =.154). BMI > 35 group had more patients with ASA score of 3 (81% vs. 32%, p <.001) and comorbid conditions such as hypertension (70% vs. 45%, p <.001), diabetes mellitus (32% vs. 15%, p <.001), and history of recurrent abdominal wall hernia (34% vs. 23%, p =.008). BMI > 35 group underwent a robotic approach at higher rates (74% vs. 45%, p <.001). Patients who underwent a Rives–Stoppa repair from the higher BMI cohort also had a larger defect size (5.6 ± 2.4 cm vs. 6.7 ± 2.4 cm, p =.004). However, there were no differences in defect size in patients who underwent a transversus abdominus release (BMI ≤ 35: 9.7 ± 4.9 cm vs. BMI > 35: 11.1 ± 4.6 cm, p =.069). Both groups benefited similarly from a short length of stay, similar hospital charges, and lower postoperative complications. Conclusion: Initial findings of our data support the benefits of elective MIS approach to AWR for patients with higher BMI. These patients derive similar benefits, such as faster recovery with low recurrence rates, when compared to lower BMI patients, while avoiding preoperative hernia incarceration, postoperative wound complications, and hernia recurrences. Future follow-up is required to establish long-term perioperative and quality of life outcomes in this patient cohort.