Multicentre, randomised trial comparing acellular porcine collagen implant versus gluteus maximus myocutaneous flap for reconstruction of the pelvic floor after extended abdominoperineal excision of rectum : study protocol for the Nordic Extended Abdominoperineal Excision (NEAPE) study

Introduction: Different surgical techniques are used to cover the defect in the floor of the lesser pelvis after an ‘extralevator’ or ‘extended’ abdominoperineal excision for advanced rectal cancer. However, these operations are potentially mutilating, and the reconstruction method of the pelvic floor has been studied only sparsely. We aim to study whether a porcine-collagen implant is superior or equally beneficial to a gluteus maximus myocutaneous flap as a reconstruction method. Methods and analysis: This is a multicentre non-blinded randomised controlled trial with the experimental arm using a porcine-collagen implant and the control arm using a gluteus maximus muscle and skin rotation flap. Considered for inclusion are patients with rectal cancer, who are operated on with a wide abdominoperineal rectal excision including most of the levator muscles and where the muscle remnants cannot be closed in the midline with sutures. Patients with a primary or recurrent rectal cancer with an estimated survival of more than a year are eligible. The randomisation is computer generated with a concealed sequence and stratified by participating hospital and preoperative radiotherapy regimen. The main outcome is physical performance 6 months after surgery measured with the timed-stands test. Secondary outcomes are perineal wound healing, surgical complications, quality of life, ability to sit and other outcomes measured at 3, 6 and 12 months after surgery. To be able to state experimental arm non-inferiority with a 10% margin of the primary outcome with 90% statistical power and assuming 10% attrition, we aim to enrol 85 patients from May 2011 onwards. Ethics and dissemination: The study has been approved by the Regional Ethical Review board at Umeå University (protocol no: NEAPE-2010-335-31M). The results will be disseminated through patient associations and conventional scientific channels