title: Fetal middle cerebral artery Doppler fluctuations after laser surgery for twin-twin transfusion syndrome.
abstract: OBJECTIVE
  The objective of this study was to compare alterations in the middle cerebral artery (MCA) pulsatility index (PI) and mean velocity (V (mean)) after laser surgery for twin-twin transfusion syndrome (TTTS).
  
  
  METHODS
  MCA Doppler studies were conducted 1 day before and after laser surgery for TTTS. The pre- and postoperative mean (standard deviation) of the MCA PI and V (mean) z-scores of the recipient and donor fetuses were calculated and compared. Data were analyzed using paired testing and multivariable linear regression models.
  
  
  RESULTS
  A total of 103 patients met the study criteria. Recipients' MCA PI increased from -1.29 (1.20) preoperatively to 0.14 (1.52) postoperatively (P < 0.0001), whereas the donors' PI did not change significantly (-0.31 (1.67) to -0.67 (1.29); P = 0.12). There was no significant difference between preoperative and postoperative MCA V (mean) in donors (0.39 (0.83) and 0.38 (0.93), respectively; P = 0.5048) or recipients (0.60 (0.74) and 0.63 (0.90), respectively; P = 0.5324).
  
  
  CONCLUSIONS
  Despite the changes in the MCA PI after laser surgery for TTTS, the MCA V (mean) remained constant. These findings may suggest some autoregulatory capacity in the cerebral vessels of the mid-trimester fetus.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Keck School of Medicine, University Southern California, Los Angeles, CA 90027, USA.
authors.forename: P
authors.initials: P
authors.lastname: Aghajanian
authors.forename: S A
authors.initials: SA
authors.lastname: Assaf
authors.forename: L M
authors.initials: LM
authors.lastname: Korst
authors.forename: D A
authors.initials: DA
authors.lastname: Miller
authors.forename: R H
authors.initials: RH
authors.lastname: Chmait
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D005330:Fetofetal Transfusion / Q000503:physiopathology / Q000601:surgery; D005333:Fetus; D006706:Homeostasis; D006801:Humans; D053685:Laser Therapy; D020768:Middle Cerebral Artery / Q000503:physiopathology*; D019990:Perioperative Care; D021041:Placental Circulation; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000503:physiopathology / Q000601:surgery; D011262:Pregnancy Trimester, Second; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal / Q000379:methods*