Prospective double-blind randomized controlled study comparing heavy- and lightweight polypropylene mesh in totally extraperitoneal repair of inguinal hernia: early results

Success of totally extraperitoneal (TEP) inguinal herniorrhaphy depends upon strengthening of the weakened native tissue by inflammation resulting in mesh-aponeurosis scar tissue (MAST) complex formation. The inflammatory response attributable to polypropylene (PP) content of the mesh is linked to weight of PP and pore size of the mesh. Continuation of the inflammatory process beyond MAST complex formation can entrap contiguous structures, leading to adverse outcome such as groin pain. Reduction of PP content has been shown to be beneficial in animal studies. Paucity of randomized controlled trials (RCTs) on human beings has left choice of mesh to surgeon preference or cost. We carried out a double-blind RCT comparing heavy- and lightweight PP-based meshes in TEP. Consecutive, married, sexually active male candidates for bilateral TEP herniorrhaphy were enrolled without any exclusion, with ethical and informed consent protocol. Standard TEP technique was followed for day-care surgery. Heavy- and lightweight meshes were implanted in each patient, one in either groin after randomization. Surgeon and patient were blinded to side of groin and type of mesh. An independent doctor (AID) evaluated the patients for groin pain, discomfort, sexual dysfunction, and clinical recurrence. A nonmedical secretary/AID transferred prospective data for both sides of groin collected by AID to Microsoft Excel. Twenty-five bilateral TEPs implanting 25 heavy- and 25 lightweight PP meshes, one of each type in each patient, were performed from December 2005 to July 2007 without difficulty or complication. Lightweight PP mesh was associated with significantly better pain scores, patient comfort, and sexual function. There was no infection or recurrence with either type of mesh. Lightweight PP mesh is associated with significantly better outcomes in TEP inguinal herniorrhaphy as compared with heavyweight PP mesh.