title: The Impact of Entry Technique and Access Diameter on Prelabour Rupture of Membranes Following Primary Fetoscopic Laser Treatment for Twin-Twin Transfusion Syndrome.
abstract: OBJECTIVE
  To evaluate the impact of entry method and access diameter at fetoscopic surgery for twin-twin transfusion syndrome in twin pregnancies with at least one survivor. The outcomes evaluated were prelabour rupture of membranes (PROM) and birth <4 weeks, preterm birth (PTB) <28 weeks, and latency to birth.
  
  
  METHODS
  A retrospective analysis of prospectively collected data of consecutive laser procedures from 6 centers was performed. Three entry methods (sheath + trocar; cannula + trocar; cannula + Seldinger) and 6 access diameters (2.3, 3.0, 3.3, 3.5, 3.8, 4.0 mm) were used. Exclusion criteria were subsequent invasive interventions, termination of pregnancy or double fetal death after laser. Multivariate analysis was performed to determine risk factors for the study outcomes.
  
  
  RESULTS
  Six hundred seventy three fetoscopic laser cases were analyzed. The use of different entry methods and access diameters did not affect PROM or birth <4 weeks, or latency from laser to birth. Access diameter was associated with PTB <28 weeks. Cervical length was associated with PROM and birth <4 weeks, and latency from laser to birth.
  
  
  CONCLUSIONS
  Instrument choice at fetoscopic laser procedures did not affect outcomes <4 weeks. Access diameter may affect the likelihood for PTB <28 weeks. Cervical length is critically associated with obstetrical outcomes following laser surgery.
authors.affiliation: Mater Mothers' Hospital, University of Western Australia, Perth, Australia.
authors.forename: Scott G
authors.initials: SG
authors.lastname: Petersen
authors.forename: Kristen S
authors.initials: KS
authors.lastname: Gibbons
authors.forename: Francois I
authors.initials: FI
authors.lastname: Luks
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Lewi
authors.forename: Anke
authors.initials: A
authors.lastname: Diemert
authors.forename: Kurt
authors.initials: K
authors.lastname: Hecher
authors.forename: Jan E
authors.initials: JE
authors.lastname: Dickinson
authors.forename: Julien J
authors.initials: JJ
authors.lastname: Stirnemann
authors.forename: Yves
authors.initials: Y
authors.lastname: Ville
authors.forename: Roland
authors.initials: R
authors.lastname: Devlieger
authors.forename: Glenn
authors.initials: G
authors.lastname: Gardener
authors.forename: Jan A
authors.initials: JA
authors.lastname: Deprest
mesh_terms: D005260:Female; D005330:Fetofetal Transfusion / Q000601:surgery*; D005332:Fetoscopy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D015999:Multivariate Analysis; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome