543 Does the time of laser usage during surgery for twin-twin transfusion syndrome impact pregnancy outcomes?

Abstract

Selective fetoscopic laser photocoagulation (SFLP) performed in twin-twin transfusion syndrome (TTTS) results in placental perfusion changes. Our objective is to evaluate pregnancy outcome in relation to the time of laser firing during surgery. Retrospective cohort study at a single fetal center of all TTTS patients treated with SFLP from April 2010 to June 2019. At the time of surgery, the time of laser firing was documented. Data collected was maternal demographic data, pregnancy characteristics and outcomes, surgical characteristics, fetal survival, and postoperative complications. Laser time was not normally distributed, thus the upper quartile (7.6 minutes (mins)) was selected as the cut-off for increased laser time. Primary outcomes were pregnancy outcomes, including survival and risk of preterm birth (PTB) at ≤26, 28, and 32 weeks. Data was analyzed using chi2, student’s t-test, multivariate logistic regression, and linear regression as appropriate. 580 patients met inclusion criteria. Median laser time was 4.9 min (range 0.2-22 min). Baseline characteristics were similar amongst groups (table). Surgery laser time >7.6 min was significantly associated with increase in number of total vessels ablated, higher rate of microseptostomy (39% vs 26%, p < 0.001), higher laser energy level (17298 vs 8608 joule, p < 0.001), and lower donor survival (71% vs 82% p = 0.004) as compared to time <7.6min respectively. Laser time <7.6min was also associated with higher rates of double survival (81.7% vs 70.1%, respectively, p = 0.034). Surgery laser time was not associated with any increased risk of PTB prior to 26, 28, and 32 weeks. Longer surgery laser time >7.6 min was associated with significant decrease in donor and double fetal survival rate. Surgery laser time did not impact gestational age at delivery. This information becomes important in surgical training for SFLP and patient counseling.View Large Image Figure ViewerDownload Hi-res image Download (PPT)