531 Evaluating surgical time in fetoscopic laser ablation. does a longer surgery equal a worse outcome?

Abstract

A longer surgery is often perceived to be more challenging but the impact of increased operative time in outcomes after selective fetoscopic laser photocoagulation (SFLP) is unknown. Our objective is to evaluate pregnancy outcome in relation to surgical time. Retrospective cohort study at a single fetal center of TTTS patients treated with SFLP from April 2010 to June 2019. Data collected was maternal demographic data, pregnancy characteristics and outcomes, surgical characteristics, fetal survival, and postoperative complications. Surgical time (time from skin incision to closure) was normally distributed, and the 75th percentile (82 minutes [min]) was selected as the cut-off for increased surgical time. Primary outcomes were risk of preterm birth (PTD) at < 26, 28, and 32 weeks. Secondary analysis was performed with the 90th percentile (112 min). Data was analyzed using chi2, student’s t-test, multivariate logistic regression, and linear regression as appropriate. 538 pregnancies met inclusion criteria. SFLP mean time was 69 ± 9.8 min (range 9-220 min) and median was 63 min (IQR 49, 82). Amongst groups, baseline characteristics were similar with the exception of race. Surgical time > 82 min had higher laser time (641.9 ± 129.1 vs 340.0 ± 238.7 seconds, p <0.001) and laser energy exposure (12874.2 ± 9105.4 vs 10052.1 ± 6889.7 joules, p<0.001). There was no significant difference in fetal survival (Table). Time ≥ 82 min was not associated with any increased risk of PTD < 26, 28, and 32 weeks (Figure). Comparing surgical time ≥ 112 min (90%tile) to < 112 minutes, there is decreased mean gestational age at delivery (28.9 ± 3.9 vs 30.7 ± 3.9 weeks, p=0.002) , increased risk of PTD at < 26 weeks and nearly 3-fold increased risk of PTD < 32 weeks, even when adjusting for baseline differences (aRR 2.9, 95% CI 1.4-6.0) (Figure). SFLP surgical time >112 minutes was associated with significant decrease in gestational age at delivery and almost 3x increase in rate of PTD <26 and <32 weeks. These are important information in patient counseling and management postoperatively.View Large Image Figure ViewerDownload Hi-res image Download (PPT)