title: Systematic review for paediatric metachronous contralateral inguinal hernia: a decreasing concern.
abstract: OBJECTIVE
  Controversy still surrounds the treatment of the asymptomatic inguinal region in paediatric patients with a unilateral inguinal hernia. The concern is the development of a future metachronous contralateral inguinal hernia (MCIH) and therefore the need for a second operation. Our aim was to provide a current systematic review of the evidence for routine contralateral exploration, and identify potential at-risk groups.
  
  
  METHODS
  Comprehensive review of the literature utilising broad search terms to identify all relevant publications. Precise inclusion and exclusion criteria to identify studies that included paediatric unilateral inguinal hernia repair without routine contralateral exploration.
  
  
  METHODS
  Chi-square with Yates' correction or a Fisher's exact test as appropriate. Numbers needed to treat (NNT) calculated with 95% confidence intervals.
  
  
  RESULTS
  A total of 7,130 titles and abstracts were screened and 61 studies included with data on 49,568 paediatric patients with a unilateral inguinal hernia fulfilling the inclusion criteria. 2,857 of these patients later developed a MCIH, revealing an overall risk is 5.76% (95% CI: 5.55-5.97%). The NNT for a MCIH is 18 (95% CI: 16.8-18) with 18 contralateral exploration required for the prevention of one MCIH. Patients <6 months at the time of the initial intervention were more likely to develop a MCIH; 183/1,470 (<6/12) versus 144/2,044 (≥6/12), P < 0.0001. As were patients with an original left-sided hernia; 815/6,739 versus 865/12,615, P < 0.0001. The NNTs for both of these groups were 9. There was no association with the gender of the patient; 888/14,480 (♂) versus 268/4,206 (♀), P = 0.37.
  
  
  CONCLUSIONS
  There is insufficient evidence to support the routine contralateral inguinal exploration in all paediatric patients presenting with a unilateral inguinal hernia. However, with patients presenting with an originally left-sided hernia or who are less than 6 months old, a parental discussion should occur about the possible benefits and risks of contralateral exploration.
authors: Department of Paediatric Surgery, Royal Alexandra Hospital for Sick Children, Brighton, UK. nataraja@doctors.org.uk
authors: Ramesh M
authors: RM
authors: Nataraja
authors: Anies A
authors: AA
authors: Mahomed
references: Pediatr Surg Int. 2010 Jul;26(7):703-6
references: 20454795
references: AMA J Dis Child. 1956 Sep;92(3):266-71
references: 13354157
references: Hernia. 2009 Dec;13(6):613-5
references: 19641844
references: Acta Chir Belg. 1996 Feb;96(1):28-30
references: 8629384
references: Stanford Med Bull. 1957 May;15(2):83-9
references: 13433076
references: J Pediatr Surg. 1984 Dec;19(6):832-7
references: 6520682
references: J Pediatr Surg. 1993 Aug;28(8):1026-7
references: 8229590
references: Am Surg. 1986 Feb;52(2):70-1
references: 3946938
references: J Laparoendosc Adv Surg Tech A. 2010 Apr;20(3):305-9
references: 20374016
references: Mayo Clin Proc. 1967 Mar;42(3):129-36
references: 6019159
references: J Pediatr Surg. 1998 Jul;33(7):1099-102; discussion 1102-3
references: 9694102
references: Postgrad Med. 1957 Aug;22(2):122-31
references: 13465540
references: Am J Surg. 1962 Apr;103:453-6
references: 14476417
references: J Pediatr Surg. 1998 Jun;33(6):874-9
references: 9660219
references: J Pediatr Surg. 2000 Dec;35(12):1746-8
references: 11101728
references: Br J Surg. 1985 Jun;72(6):485-7
references: 4016518
references: Va Med Mon (1918). 1959 Jun;86(6):314-8
references: 13659836
references: Surg Endosc. 2010 Jan;24(1):21-4
references: 19690916
references: JAMA. 1961 Apr 15;176:110-3
references: 13746403
references: Am J Surg. 1997 Dec;174(6):741-4
references: 9409609
references: Br J Surg. 2001 May;88(5):720-3
references: 11350448
references: Hernia. 2008 Apr;12(2):113-5
references: 18060351
references: Pediatr Surg Int. 2009 Mar;25(3):229-33
references: 19139909
references: Pediatr Surg Int. 2010 Apr;26(4):387-92
references: 20143077
references: Curr Opin Pediatr. 2007 Jun;19(3):344-8
references: 17505198
references: J Pediatr Surg. 2004 Mar;39(3):480-2; discussion 480-2
references: 15017573
references: J Pediatr Surg. 1997 Mar;32(3):445-7
references: 9094014
references: Surg Gynecol Obstet. 1953 Nov;97(5):603-7
references: 13113540
references: Pediatr Surg Int. 2002 Sep;18(5-6):470-1
references: 12415383
references: Arch Surg. 1963 Jun;86:1072-4
references: 14026218
references: J Pediatr Surg. 1992 Oct;27(10):1322-4
references: 1403513
references: J Pediatr Surg. 1999 May;34(5):684-7; discussion 687-8
references: 10359164
references: J Pediatr Surg. 1989 Oct;24(10):963-5
references: 2809965
references: J Pediatr Surg. 1980 Jun;15(3):313-7
references: 7381667
references: J Pediatr Surg. 2010 Apr;45(4):789-92
references: 20385288
references: Br J Surg. 2007 Jul;94(7):804-11
references: 17571299
references: J Pediatr Surg. 2005 Jul;40(7):1163-6
references: 16034763
references: East Afr Med J. 2004 Nov;81(11):574-6
references: 15868966
references: Eur J Pediatr Surg. 1995 Jun;5(3):152-5
references: 7547801
references: Surg Endosc. 2005 Jul;19(7):927-32
references: 15920685
references: Aust Paediatr J. 1982 Mar;18(1):55-7
references: 7103881
references: Pediatr Surg Int. 2003 Apr;19(1-2):68-70
references: 12721728
references: J Laparoendosc Adv Surg Tech A. 2006 Dec;16(6):650-3
references: 17243890
references: Ir J Med Sci. 2003 Jan-Mar;172(1):18-9
references: 12760457
references: J Am Med Assoc. 1959 Sep 19;171:287-90
references: 14409009
references: J Pediatr Surg. 2010 Apr;45(4):793-5
references: 20385289
references: Surgery. 1958 Oct;44(4):735-40
references: 13592622
references: Surg Clin North Am. 2008 Feb;88(1):27-43, vii-viii
references: 18267160
references: J Pediatr Surg. 2005 Jan;40(1):75-80
references: 15868562
references: J Pediatr Surg. 2005 Jun;40(6):1009-14
references: 15991187
references: Pediatr Surg Int. 2009 Jan;25(1):69-71
references: 18989679
references: Acta Chir Scand. 1970;136(8):707-9
references: 5518148
references: J Pediatr Surg. 1995 Dec;30(12):1684-6
references: 8749924
references: J Pediatr Surg. 2006 May;41(5):980-6
references: 16677897
references: J Pediatr Surg. 2005 Jun;40(6):1058-9; author reply 1059-60
references: 15991196
references: J Pediatr Surg. 1994 Nov;29(11):1496-8
references: 7844731
references: Surg Endosc. 2004 Jun;18(6):957-60
references: 15095082
references: J Pediatr Surg. 2002 May;37(5):745-51
references: 11987092
references: Surgery. 1949 Feb;25(2):307-28
references: 18124118
references: Am Surg. 1960 Jul;26:470-5
references: 13814430
references: Am J Surg. 1962 Jul;104:52-3
references: 13904248
references: Ann Surg. 1958 Nov;148(5):819-22
references: 13595542
references: Pediatr Surg Int. 2009 Sep;25(9):759-62
references: 19652984
references: J Chir (Paris). 1987 Jun-Jul;124(6-7):391-3
references: 3624332
references: J Pediatr Surg. 2003 May;38(5):756-7
references: 12720187
references: Hernia. 2006 Mar;10(1):74-8
references: 16362231
references: N C Med J. 1970 Jun;31(6):222-4
references: 5269714
references: Hernia. 2008 Dec;12(6):631-4
references: 18594755
references: Hernia. 2009 Feb;13(1):41-3
references: 18636222
references: Am Surg. 1961 Mar;27:182-5
references: 13767413
references: Surgery. 1962 Mar;51:393-406
references: 13915570
references: J Pediatr Surg. 2006 Dec;41(12):2004-7
references: 17161192
references: Surgery. 1955 Jun;37(6):947-50
references: 14373316
references: Semin Pediatr Surg. 2007 Feb;16(1):50-7
references: 17210483