title: Previous portal hypertension surgery negatively affects results of mesenteric to left portal vein bypass.
abstract: OBJECTIVE
  The mesenteric to left portal vein bypass (MLPVB) has been successfully used to treat extrahepatic portal vein obstruction (EHPVO) in children. We examined the effect of failed prior surgical or radiological procedures intended to treat complications of portal hypertension on the success rate of subsequent MLPVB surgery.
  
  
  METHODS
  Sixty-two patients younger than 18 years with EHPVO underwent MLPVB between 1997 and 2006. Children were divided into 3 groups: those with no prior surgery related to portal hypertension, those with prior portosystemic shunts, and those with either splenectomy or mesenteric vascular embolization procedures. The effect of prior procedures on the patency rate of the MLPVB was then examined.
  
  
  RESULTS
  Of 62 children, 11 (17.7%) had significant procedures to treat symptoms of portal hypertension: 6 had at least 1 portosystemic shunt attempt, 3 had isolated splenectomy, and 2 had embolization of the splenic artery or coronary and peripancreatic varices. Patients with previous portal hypertension surgery were significantly older and larger than those with no surgery. Patients with no prior interventions had a significantly higher MLPVB patency rate (88.2%, 45/51) than those with no prior interventions (63.6%, 7/11). Prior splenectomy alone was not found to adversely affect MLPVB. Patients with prior embolization procedures or unsuccessful shunts had significantly poorer successful outcomes (0% and 66.7%) than those with no prior interventions (88.2%; P < .005).
  
  
  CONCLUSIONS
  The results demonstrate that prior portosystemic shunts or mesenteric embolizations have a deleterious effect on outcome after MLPVB and should be avoided whenever possible. This study suggests that patients with symptomatic EHPVO should undergo MLPVB as a primary intervention rather than as a rescue procedure to optimize MLPVB patency.
authors.affiliation: Division of Pediatric Surgery, Children's Memorial Hospital, Feinberg School of Medicine, Northwestern University, Chicago, IL 60614, USA.
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Chin
authors.forename: Fiona
authors.initials: F
authors.lastname: Thow
authors.forename: Riccardo A
authors.initials: RA
authors.lastname: Superina
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D000714:Anastomosis, Surgical / Q000379:methods; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006975:Hypertension, Portal / Q000175:diagnosis / Q000601:surgery*; D007223:Infant; D008102:Liver Circulation / Q000502:physiology; D008297:Male; D008642:Mesenteric Veins / Q000601:surgery; D017082:Portal Pressure; D011169:Portal Vein / Q000601:surgery; D011170:Portasystemic Shunt, Surgical / Q000009:adverse effects / Q000379:methods*; D011336:Probability; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000379:methods*; D020246:Venous Thrombosis / Q000601:surgery*