Outcomes of soft-tissue reconstruction for isolated type III internal hemipelvectomy

Aims: A type III internal hemipelvectomy includes resection of the pubic rami. Although bony reconstruction is not necessary, the integrity of the abdominal wall is deficient following resection. The aim of this study was to report the outcome of soft-tissue reconstruction following these resections. Methods: We retrospectively reviewed all isolated type III internal hemipelvectomies which were undertaken at the Mayo Clinic (Rochester, USA) between January 2002 and December 2022. The group included 25 patients, of whom 14 (56%) were male. Their median age was 45 years (IQR 61 to 31) at the time of surgery. Most patients (n = 18; 72%) underwent resection for a sarcoma. Soft-tissue flaps were used in 21 patients (84%) and nine also had a mesh reconstruction. Results: The five-year disease-specific survival was 65% following surgery, with significantly worse survival in patients with locally advanced tumour (35% (95% CI 12 to 100) vs 76% (95% CI 59 to 99); p = 0.036). Complications were common, with 21 patients (84%) having at least one complication, and 12 (48%) having several complications. Most commonly, this included seroma or haematoma (44%), wound dehiscence (40%), and infection (40%). The use of a soft-tissue flap did not significantly reduce the risk of infection (hazard ratio (HR) 0.68 (95% CI 0.14 to 3.28); p = 0.638) or seroma or haematoma (HR 0.31 (95% CI 0.30 to 4.14); p = 0.088), but patients who did not have a soft-tissue flap were significantly more likely to develop a hernia (odds ratio 9.0 (95% CI 1.14 to 71.03); p = 0.027). A total of three of 21 patients (14%) whose reconstruction involved a flap had donor site complications. Conclusion: Soft-tissue reconstruction following a type III internal hemipelvectomy reduces the risk of postoperative hernia formation, with a low rate of donor site complications. This additional procedure should be considered for all patients undergoing this type of resection.