We hypothesized that laser surgery for twin-twin transfusion syndrome (TTTS) would result in fetal hemodynamic alterations reflected by changes in cerebral blood flow velocities. The study objective was to compare the middle cerebral artery (MCA) pulsatility index (PI) before and after laser surgery for TTTS.
A prospective observational study of TTTS patients was conducted. MCA Doppler examination was attempted within 24 hours before and after laser surgery for TTTS. Patients were excluded from analysis if MCA PI Doppler measurements were unavailable. The mean (standard deviation) pre- and postoperative MCA PI′s of the recipient and donor fetuses were compared. Demographic and outcome data were analyzed in relation to the MCA PI′s. Student t-tests were used for analysis.
99 patients underwent laser surgery for TTTS during the study period, of which 61 had pre- and postoperative MCA Doppler data on both fetuses, 27 did not have all data recorded, and 11 had postoperative demise precluding Doppler analysis. The mean MCA PI for the recipients increased from 1.35 (0.38) preoperatively to 1.86 (0.86) postoperatively (p<0.001), while the mean MCA PI for the donors decreased from 1.67 (0.65) to 1.48 (0.42, p=0.04). Preoperatively, the recipients had a lower mean MCA PI compared to the donors (p=0.001), while postoperatively the recipients had a higher mean MCA PI compared to the donors (p=0.003). No significant correlations were identified between the MCA PI′s and demographic factors (Quintero Stage, donor growth restriction) or outcomes (gestational age at delivery, survival).
Laser surgery for TTTS resulted in increased recipient and decreased donor MCA pulsatility. These opposing alterations in cerebral blood flow velocities may, in part, be attributable to a decrease in fetal arterial blood pressure and/or systemic and cerebral blood flow in the recipient and a corresponding increase in these parameters in the donor.
© 2008 Mosby, Inc. Published by Elsevier Inc. All rights reserved.