title: Chronic pain after laparoscopic transabdominal preperitoneal hernia repair: a randomized comparison of light and extralight titanized polypropylene mesh.
abstract: BACKGROUND
  The aim of this prospective, randomized, single-blinded clinical trial was to compare the incidence of chronic pain after laparoscopic transabdominal preperitoneal hernia repair (TAPP) using a 35-g/m2 titanized polypropylene mesh and a 16-g/m2 titanized polypropylene mesh. The reported incidence of chronic pain in patients who underwent laparoscopic hernia repair is a serious problem. The techniques of dissection, mesh fixation, and the mesh material used have all been identified as being part of the problem. Excellent biocompatibility through a unique combination of a lightweight open porous polypropylene mesh covered with a covalent-bonded titanium layer has been claimed. The aim of this study was to find out whether the titanium surface alone or the difference in material load between the two available meshes influences clinical outcomes.
  
  
  METHODS
  Three hundred eighty patients with 466 inguinal hernias were operated on between 2002 and 2006 with the laparoscopic transabdominal preperitoneal (TAPP) technique. Mesh fixation with staples was carried out routinely. After the dissection was completed just prior to the implantation of the mesh, patients were randomized into two groups. In Group A, 250 (53.6%) inguinal hernias were repaired with a 35-g/m2 titanized polypropylene mesh, and in Group B, 216 (46.4%) inguinal hernias were repaired with a 16-g/m2 titanized polypropylene mesh. The primary outcome was chronic pain 3 years after surgery. The degree of pain was determined using a visual analog scale (VAS) with a range from 0 to 10. The secondary outcome was the rate of recurrence.
  
  
  RESULTS
  The postoperative period of observation was at least 3 years for every patient. In both groups, 90% of the patients could be questioned and examined clinically: in Group A (Light), 5.3% of the patients and in Group B (Extralight), 1.5% of the patients suffered from chronic pain. Chronic pain was significantly more common in Group A than in Group B (p=0.037). There was no difference with respect to the rate of recurrence: for Group A it was 3.1% and for Group B it was 2.6% (p=0.724).
  
  
  CONCLUSIONS
  Chronic pain is not very common in patients who have had their inguinal hernias repaired with titanium-covered polypropylene mesh. Reducing the material load from 35 to 16 g/m2 seems to further improve the biocompatibility of these meshes, thus improving the clinical outcome by reducing chronic pain to a rare event. The role of staples in causing chronic pain following inguinal hernia repair may be overestimated. There was no evidence supporting the notion that the use of the 16-g/m2 titanized meshes is associated with increased recurrence rates.
authors.affiliation: Department of General, Visceral and Vascular Surgery, Agatharied Academic Teaching Hospital of the Ludwig-Maximilians-University Munich, St. Agathastr. 1, 83734, Hausham/Oberbayern, Germany. sallerschopf@aol.com
authors.forename: Stefan
authors.initials: S
authors.lastname: Schopf
authors.forename: Thomas
authors.initials: T
authors.lastname: von Ahnen
authors.forename: Martin
authors.initials: M
authors.lastname: von Ahnen
authors.forename: Hans
authors.initials: H
authors.lastname: Schardey
mesh_terms: D002908:Chronic Disease; D003663:Decision Trees; D004867:Equipment Design; D005260:Female; D059685:Herniorrhaphy; D006801:Humans; D015994:Incidence; D010535:Laparoscopy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000453:epidemiology / Q000209:etiology*; D010537:Peritoneum; D011126:Polypropylenes; D011446:Prospective Studies; D016037:Single-Blind Method; D013526:Surgical Mesh; D011795:Surveys and Questionnaires; D014025:Titanium
chemical_list: D011126:Polypropylenes; D014025:Titanium