The use of gluteus maximus to restore the function of the pelvic diaphragm in the reconstruction of the pelvic outlet after abdomino-perineal resection: a case series

Background Challenges encountered during reconstruction of perineal defects following abdomino-perineal resection (AP resection) include the large volume of dead space, the risk of herniation and high rates of wound complications. There are various methods of flap reconstruction, such as the vertical rectus abdominis muscle flap. This article describes an alternative method for pelvic outlet reconstruction based on a single, pedicled, gluteus maximus muscle. This may act as a dynamic sling and restore the function of the pelvic diaphragm to support the intra-abdominal contents, to reduce the formation of a hernia. Methods A case series presenting four patients undergoing reconstruction following AP resection, between 2013 and 2018, was performed, in a tertiary centre with an established service providing abdominal and perineal reconstruction. Results A total of four patients underwent gluteal muscle flap reconstruction, following primary AP resection for rectal malignancy. Primary reconstruction was performed in two patients. The other two patients underwent delayed (or secondary) reconstruction, to improve symptomatic herniation. All four patients had initial dehiscence of their perineal wound within 4 weeks post-operatively, though no patients required surgical management for infection or exposed mesh. The two patients who underwent delayed reconstruction had complete resolution of their herniation symptoms. Conclusions The pedicled gluteus muscle flap provides an option for local reconstruction of large perineal defects, as it creates an innervated muscle sling to restore the support function of the pelvic diaphragm, reducing the risk of long-term hernia formation. Level of evidence Level V, Therapeutic