title: Influence of experience, case load, and stage distribution on outcome of endoscopic laser surgery for TTTS--a review.
abstract: OBJECTIVE
  Survival (> or =1 twin) after laser surgery for patients with twin-to-twin transfusion syndrome (TTTS) ranges from 65 to 93%. However, most studies are noncontrolled and retrospective, and have included a limited number of patients. The aim of this study was to perform a systematic review of outcomes after laser surgery in patients with TTTS.
  
  
  METHODS
  We conducted database and manual searches of reference lists and pertinent journals published between 1995 and 2009 that report outcomes of laser surgery in patients with TTTS. Two authors performed the search independently of each other. There exist only two randomized controlled trials, each with fewer than 80 patients having undergone laser surgery. Uncontrolled and retrospective series were therefore considered as well. Studies had to report sufficient information on inclusive dates, stage distribution, overall neonatal survival, and neonatal survival of at least one twin. Of the 486 studies identified, we considered 19 studies.
  
  
  RESULTS
  For each series, 95% confidence intervals (CI) were calculated. Survival was plotted against the date of publication, number of patients/series, gestational age at delivery, and proportion of advanced cases. Univariate analysis was performed to detect significant differences. Our meta-analysis, which included 1484 patients, shows 81.2% survival of at least one twin (CI: 79.1-83.2%). The average survival of at least one twin for the entire population remained within the CI of all but one series. Neither case load, nor stage distribution, nor chronological date of the study affected the survival.
  
  
  CONCLUSIONS
  A systematic review of endoscopic laser surgery performed in patients with TTTS failed to show a significant impact of high caseloads, disease severity distribution, or improvements in technique.
authors.affiliation: Program in Fetal Medicine, Alpert Medical School of Brown University, Providence, RI, USA.
authors.forename: Shair
authors.initials: S
authors.lastname: Ahmed
authors.forename: Francois I
authors.initials: FI
authors.lastname: Luks
authors.forename: Barbara M
authors.initials: BM
authors.lastname: O'Brien
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Muratore
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Carr
mesh_terms: D005260:Female; D005330:Fetofetal Transfusion / Q000601:surgery*; D005332:Fetoscopy; D006801:Humans; D053685:Laser Therapy; D011247:Pregnancy; D016896:Treatment Outcome