Learning curve analysis for competency assessment in fetoscopic laser photocoagulation for twin-twin transfusion
Vajiheh Marsoosi1, Laleh Eslamian1, Sotoudeh Mohammadi1
1Department of Obstetrics and Gynecology Shariati Hospital Tehran University of Medical Sciences Tehran Iran.
Objective:
To evaluate the learning curve (LC) and skill acquisition for selective fetoscopic laser photocoagulation (sFLP) using cumulative analysis for twin-twin transfusion syndrome (TTTS) treatment in middle-resource settings.
Method:
Two novices with prior expertise in maternal-fetal medicine and minimally invasive procedures underwent a four-phase training program for sFLP. The program included literature reviews, observational fellowships, hands-on simulator training, and surgeries performed under direct supervision at a large tertiary referral center in Iran. Between October 2018 and May 2023, they independently managed and performed sFLP on 230 patients with TTTS. Performance was evaluated using cumulative sum (CUSUM) and learning curve CUSUM (LC-CUSUM) analyses.
Results:
At birth, among the 228 pregnancies included in the birth survival analysis, 81.5% had at least one surviving twin, including 109 patients (47.8%) with survival of both twins, whereas 42 pregnancies (18.5%) resulted in double fetal demise. The learning curve analysis estimated an overall failure probability of 0.18 (95% confidence interval [CI], 0.13-0.23), with a survival probability of 0.82 (95% CI, 0.77-0.87). For outcomes with at least one survivor, the predefined competency threshold was achieved after the 80th patient, after which acceptable performance was maintained throughout the remainder of the study. For double-twin survival, the probability of failure was 0.52 (95% CI, 0.41-0.54). The predefined competency threshold was achieved after the 110th procedure, after which acceptable performance was similarly maintained throughout the remainder of the study. These findings demonstrate progressive skill acquisition and operational consistency through structured training and continuous quality control.
Conclusion:
Structured training enabled acquisition of procedural competency after 80 procedures for outcomes with at least one survivor and 110 procedures for double-twin survival. LC-CUSUM and CUSUM analyses provide an objective framework for monitoring implementation of new fetal therapy programs and may support safe expansion of fetoscopic laser photocoagulation in resource-constrained settings.
