title: Unexpected metachronous hernia development in children following laparoscopic unilateral hernia repair with negative evaluation for contralateral patent processus vaginalis.
abstract: BACKGROUND
  Metachronous hernia has been reported to develop unexpectedly in children after negative evaluation for contralateral patent processus vaginalis (CPPV) by transinguinal laparoscopy. Scarce data exist regarding such phenomena following laparoscopic unilateral hernia repair and negative findings for CPPV in transumbilical laparoscopy.
  
  
  METHODS
  A retrospective study was performed to investigate metachronous hernia development in a cohort of consecutive children who had undergone laparoscopic unilateral hernia repair with negative findings of CPPV by transumbilical laparoscopy 5 or more years ago.
  
  
  RESULTS
  Study subjects included 293 children 1 month to 15 years old at the time of laparoscopic unilateral hernia repair (left, n=116; right, n=177). There were 246 boys and 47 girls. Nine children (3.1%), all boys, developed metachronous hernia at a median of 24 months (range, 6-42 months) from the time of negative laparoscopic evaluation for CPPV. There was no statistical difference between the genders and laterality of the initial hernia in the development of metachronous hernia.
  
  
  CONCLUSIONS
  False-negative CPPV evaluation by transumbilical laparoscopy during laparoscopic unilateral hernia repair can occur and result in unexpected metachronous hernia development. Further prospective studies are warranted to develop effective maneuvers in addition to inspection alone to reduce false-negative laparoscopic assessment.
authors: Division of Paediatric Surgery & Paediatric Urology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China. pyhtam@surgery.cuhk.edu.hk
authors: Yuk Him
authors: YH
authors: Tam
authors: Yuen Shan
authors: YS
authors: Wong
authors: Kristine Kit Yi
authors: KK
authors: Pang
authors: Siu Yan
authors: SY
authors: Tsui
authors: Jennifer Wai Cheung
authors: JW
authors: Mou
authors: Christopherus Heinrich
authors: CH
authors: Houben
authors: Kin Wai
authors: KW
authors: Chan
authors: Kim Hung
authors: KH
authors: Lee
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005188:False Negative Reactions; D005260:Female; D006552:Hernia, Inguinal / Q000175:diagnosis* / Q000601:surgery*; D059685:Herniorrhaphy / Q000379:methods*; D006801:Humans; D007223:Infant; D010535:Laparoscopy; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis*; D012189:Retrospective Studies; D013997:Time Factors