title: Risk factors of postoperative morbidity in patients with uncomplicated liver hydatid cyst.
abstract: OBJECTIVE
  To determine postoperative morbidity (POM) in patients undergoing surgery for uncomplicated hepatic echinococcosis (HE) and determine associations with the variable POM looking for possible risk factors for POM.
  
  
  METHODS
  Nested case-control study. We included patients undergoing surgery for uncomplicated HE in two hospitals in Temuco between 2000 and 2012. The main outcome variable was development of POM. Other variables of interest were hospital stay, mortality and recurrence. Surgical techniques used were pericystectomy and liver resection. Descriptive statistics and analytical statistics were applied using T-test, ANOVA and Kruskal-Wallis test to compare continuous variables; Chi(2) and Fisher's exact test for categorical variables, and logistic regression models were used, estimating OR.
  
  
  RESULTS
  126 patients, median age 41 years, 61% female. The incidence of POM was 10.3%, with 76.9% Clavien grade I or II. The etiology was 6.5% and 4.1% of medical and surgical complications, respectively. There was no mortality and with a median follow-up of 83 months, recurrence incidence was 0.8%. Association was found between cases and controls and the variables age, alkaline phosphatase, cyst location and hospital stay. Applying regression models age (p = 0.002 and OR 1.07) and cyst location (p = 0.003 and OR 3.94) were found to be risk factors.
  
  
  CONCLUSIONS
  Observed POM is lower and of less severity than those previously published. Risk factors were determined.
authors.affiliation: Department of Surgery, Faculty of Medicine, Universidad de La Frontera, Manuel Montt 112, Office 408, Temuco, Chile; Center for Biomedical Research, Universidad de Autónoma, Chile. Electronic address: carlos.manterola@ufrontera.cl.
authors.forename: Carlos
authors.initials: C
authors.lastname: Manterola
authors.affiliation: PhD Program in Medical Sciences, Universidad de La Frontera, Temuco, Chile; Department of Psychology, Universidad Autónoma, Temuco, Chile.
authors.forename: Tamara
authors.initials: T
authors.lastname: Otzen
authors.affiliation: Department of Surgery, Faculty of Medicine, Universidad de La Frontera, Manuel Montt 112, Office 408, Temuco, Chile.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Urrutia
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002677:Chile / Q000453:epidemiology; D015897:Comorbidity; D004444:Echinococcosis, Hepatic / Q000453:epidemiology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D011184:Postoperative Period; D012307:Risk Factors; D055815:Young Adult
keywords: Cohort studies; Echinococcosis; Hepatic; Hepatic hydatid cyst; Morbidity; Operative; Surgical procedures