BackgroundAbdomen‐based free flaps represent the gold standard option in the armamentarium of breast reconstruction. The natural evolution to more preservation with less invasive forms of these flaps has been driven by both patient and surgeon satisfaction. Nevertheless, obese patients are challenging due to the increased risk of compromised flap perfusion and donor site morbidity. This challenge is compounded by the prevalence of obesity worldwide, resulting in more free abdominal flaps being performed for breast reconstruction in obese patients. The authors present the outcomes of a modified supra‐arcuate fascial muscle‐sparing transverse rectus abdominus myocutaneous (FMS‐TRAM) technique compared to standard muscle‐sparing transverse rectus abdominus myocutaneous (MS‐TRAM) technique to reduce the donor site morbidity while providing a well‐vascularized large volume of autologous tissue.MethodsA retrospective comparative data analysis was conducted at two centers: Cairo University Hospitals, Egypt, and University Hospitals Birmingham, United Kingdom. Standard MS‐TRAM was performed in 65 patients between 2008 and 2011 (Group 1) versus 275 patients between 2011 and 2020 (Group 2) who underwent FMS‐TRAM. The modified technique involved limiting the fascial incision to above or at the level of the arcuate line to preserve the integrity of the anterior rectus sheath caudally. All patients included were of the obese population (BMI≥30 kg/m2) and underwent unilateral post‐mastectomy reconstruction. Patient demographics, comorbidities, operative details, and outcomes focusing on donor site morbidity and flap complications were recorded and compared between the two groups.ResultsThe median age and BMI for Group 1 were 43 and 32, respectively. While for Group 2, they were 47 and 33, respectively. Flap weight ranged from 560 to 1470 g (Mean 705) for Group 1, while Group 2 ranged from 510 to 1560 (mean 715). The majority (280/340 [82%]) of the patients in both groups received radiotherapy. 7.7% of Group 1 were smokers, while in Group 2 it was 4.7%. The percentage of delayed versus immediate reconstruction in Group 1 was 60%/40%, while in Group 2, it was 43%/56%. The incidence of fat necrosis, partial necrosis, and total necrosis was 7.6%.1.5%, and 3%, respectively, for Group 1 and 8%, 1.4%, and 2.6%, respectively, for Group 2. The two‐tailed p‐value demonstrated a significant statistical difference (p < 0.00001) in donor site morbidity between both groups, with more bulge 20% (13/65) and hernia 1.5% (2/65) occurrence in Group 1 versus 1.9% (5/275) and 0.7% (2/275) in Group 2 respectively, over a follow‐up period ranging from 24 to 60 months (mean 32).ConclusionFMS‐TRAM flaps are safe, robust, and reliable with less donor site morbidity while maintaining optimal flap perfusion for large volume flaps in obese patients with excellent, durable outcomes. It should be considered a valuable tool in the reconstructive armamentarium of breast reconstruction.