Biological Mesh Closure of the Pelvic Floor After Extralevator Abdomino Perineal Resection for Rectal Cancer

The eAPR procedure will be performed in an identical way as described for the control arm of the study, and this is preferably followed by an omental plasty. The intervention in the experimental arm consists of suturing an acellular biological mesh derived from porcine dermis in the pelvic floor defect (Strattice™, 6x10 cm). The mesh will be sutured at each side of the coccyx or distal sacrum with Prolene or PDS to the discretion of the surgeon. Laterally, the mesh is attached to the remainings of the levator complex and, anteriorly, to the transverse perineal muscle or posterior vaginal wall. A suction drain will be inserted and positioned on top of the mesh. The perineal subcutaneous fat and skin will be subsequently closed in layers similar to primary simple closure as performed in the standard arm.

The perineal phase of the APR will be performed according to the principles of an extralevator APR, which means that the levator muscles will be laterally transected in order to leave a muscular cuff around the tumour. The coccyx will not be routinely resected, but only if indicated based on surgical exposure or oncological principles. The extent of excision of perineal skin and ischioanal fat will be as limited as oncologically justified. Preferably, an omental plasty is positioned in the pelvic cavity following resection. Closure of the perineum in the control arm consists of stitching the perineal subcutaneous fat together using interrupted Vicryl sutures in one or two layers. Subsequently, the skin will be closed using interrupted sutures according to the preference of the surgeon. Placement of a transabdominal or transperineal drain will be at the discretion of the surgeon.