title: Residual vascular communications in twin-twin transfusion syndrome treated with sequential laser surgery: frequency and clinical implications.
abstract: OBJECTIVE
  The goal of fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS) is to ablate all placental vascular communications, thereby separating the fetal circulatory systems. We sought to ascertain the frequency and clinical implications of residual vascular communications (RVC) post preferential sequential selective laser photocoagulation of communicating vessels (SQLPCV).
  
  
  METHODS
  TTTS placentas treated via preferential SQLPCV were examined. Patency of vascular communications was assessed via water and/or milk injections. Cases with intrauterine fetal demise or placental disruption were excluded. Outcomes with and without RVC were compared.
  
  
  RESULTS
  One hundred seventy-four TTTS patients were treated during the study period. Dual survival at birth was 76% (133/174). Of the 133 dual survivors, 105 (79%) submitted an intact placenta. Five of these 105 placentas had RVC (4.8%). Comparison of RVC versus non-RVC cases revealed the following: gestational age at delivery 28.7(6.5) vs. 33.4(3.3) weeks (p=0.178); recipient birth weight 1287(1061) vs. 1973(610) grams (p=0.020); donor birth weight 1429(1369) vs. 1653(715) grams (p=0.518); donor central/eccentric placental cord insertion 80% vs. 17% (p=0.006). One case required a second laser surgery to complete the laser ablation; this placenta did not have RVC after delivery. Otherwise there were no cases of persistent TTTS. One of the 5 RVC cases (20%) exhibited neonatal findings consistent with twin anemia-polycythemia sequence (TAPS), while none of the non-RVC cases had TAPS (p=0.005).
  
  
  CONCLUSIONS
  The rate of RVC was less than 5% among gestations with dual survivors post preferential SQLPCV treatment for TTTS.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Keck School of Medicine, University Southern California, Los Angeles, CA 90027, USA. chmait@usc.edu
authors.forename: R H
authors.initials: RH
authors.lastname: Chmait
authors.forename: S A
authors.initials: SA
authors.lastname: Assaf
authors.forename: K
authors.initials: K
authors.lastname: Benirschke
mesh_terms: D005260:Female; D005330:Fetofetal Transfusion / Q000601:surgery*; D005332:Fetoscopy; D006801:Humans; D007231:Infant, Newborn; D053685:Laser Therapy; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D016896:Treatment Outcome