title: Spectrum of anorectal anomalies in pygopagus twins.
abstract: OBJECTIVE
  The literature lacks a concise description of the anorectal anomalies encountered in pygopagus twins.
  
  
  METHODS
  This is a retrospective literature review of 34 pygopagus twins highlighting their anorectal malformations.
  
  
  RESULTS
  Overall pygopagus twins represent 17% of all conjoined twins. Live-birth pygopagus twins are more commonly female (86%), whereas stillborns are commonly male (80%). Half of the twins had nonfused rectums, and half had fused rectums. The nonfused had 2 rectums (80%) or one rectum and one rectovaginal fistula (20%). The fused had high (46%) or low (54%) rectal junctions. All reported living male pygopagus twins have had nonfused rectums. All can be managed applying the principles of posterior sagittal anorectoplasty.
  
  
  CONCLUSIONS
  In general, live-born male pygopagus twins are likely to survive with a nonfused rectum and good bowel function, whereas live-born female pygopagus twins have a good chance of surviving with a fused rectum (high or low), which requires appropriate operative reconstruction.
authors.affiliation: Department of Pediatric Surgery, The Children's Hospital/University of Colorado Health Sciences Center, Denver, CO 80218, USA.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Janik
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Hendrickson
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Janik
authors.forename: Denis D
authors.initials: DD
authors.lastname: Bensard
authors.forename: David A
authors.initials: DA
authors.lastname: Partrick
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Karrer
mesh_terms: D000015:Abnormalities, Multiple / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery; D001003:Anal Canal / Q000002:abnormalities* / Q000601:surgery; D004200:Diseases in Twins / Q000453:epidemiology*; D005260:Female; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012006:Rectovaginal Fistula / Q000209:etiology; D012007:Rectum / Q000002:abnormalities* / Q000601:surgery; D012189:Retrospective Studies; D012737:Sex Factors; D013131:Spine / Q000002:abnormalities; D016019:Survival Analysis; D014428:Twins, Conjoined / Q000473:pathology*; D014621:Vagina / Q000002:abnormalities / Q000601:surgery