title: Morphology-based investigation of metachronous inguinal hernia after negative laparoscopic evaluation - is it acquired indirect inguinal hernia?
abstract: OBJECTIVE
  Patients who developed apparent metachronous contralateral inguinal hernia (MCIH) after negative laparoscopic diagnosis have been reported. We performed this study to investigate the morphological characteristics and etiology of this phenomenon.
  
  
  METHODS
  A consecutive series of 1,747 patients (858 boys and 889 girls) with symptomatic unilateral inguinal hernia were studied. During laparoscopic percutaneous completely extraperitoneal closure, morphological appearances at the asymptomatic groin were inspected for contralateral patent processus vaginalis (CPPV) with definitive criteria. If positive CPPV was identified, it was closed by the same technique used for the affected side. The patients were reviewed for occurrence of metachronous contralateral hernia.
  
  
  RESULTS
  A total of 755 patients (43.2%) had positive CPPV. Of the 992 patients whose CPPVs were evaluated as true negative, eight (seven boys, one girl) developed MCIH (time taken, three months to five years six months). During second-look operations, morphological appearances of the CPPV that was originally considered as true negative CPPV was found to be wide open.
  
  
  CONCLUSIONS
  Despite a true negative evaluation by laparoscopy, there was a 0.8% chance of developing a MCIH. This phenomenon was male-oriented and may be acquired indirect inguinal hernia without preceding of CPPV.
authors.affiliation: Division of Surgery, Department of Surgical Specialties, National Center for Child Health and Development, Tokyo, Japan; Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan. Electronic address: watanabe-ts@ncchd.go.jp.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Yoshida
authors.affiliation: Division of Surgery, Department of Surgical Specialties, National Center for Child Health and Development, Tokyo, Japan; Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan.
authors.forename: Michinobu
authors.initials: M
authors.lastname: Ohno
authors.affiliation: Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Mori
authors.affiliation: Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tomita
authors.affiliation: Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan; Department of Pediatric Surgery, Kyorin University School of Medicine, Tokyo, Japan.
authors.forename: Etsuji
authors.initials: E
authors.lastname: Ukiyama
authors.affiliation: Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan.
authors.forename: Miwako
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Pediatric Surgery, Saitama City Hospital, Saitama, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Endo
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006552:Hernia, Inguinal / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology / Q000601:surgery; D059685:Herniorrhaphy / Q000379:methods; D006801:Humans; D007223:Infant; D010535:Laparoscopy; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D011446:Prospective Studies
keywords: Children; Contralateral manifestation; False negative laparoscopy; Indirect inguinal hernia; Metachronous inguinal hernia