Preoperative Ultrasound Prediction of Essential Landmarks for Successful Fetoscopic Laser Treatment of Twin-Twin Transfusion Syndrome

Abstract

Introduction: The insertion site of the fetoscope for laser occlusion (FLOC) treatment of twin-twin transfusion syndrome (TTTS) determines the likelihood of treatment success. We assessed a standardized preoperative ultrasound approach for its ability to identify critical landmarks for successful FLOC. Methods: Three surgeons independently performed preoperative ultrasound and deduced the likely orientation of the intertwin membrane (ITM) and vascular equator (VE) based on the sites of the cord insertion, the lie of the donor, and the size discordance between twins. At FLOC, these landmarks were visually verified and compared to preoperative assessments. Results: Fifty consecutive FLOC surgeries had 127 preoperative assessments. Basic ITM and VE orientation were accurately predicted in 115 (90.6%), 109 (85.8%), and 105 (82.7%) assessments. Predictions were anatomically correct in 96 (75.6%), 70 (55.1%), and 58 (45.7%) assessments with no differences in accuracy between operators of different training level. The ITM/VE relationship was most poorly predicted in stage-3 TTTS (χ², p = 0.016). Conclusion: In TTTS, preoperative ultrasound identification of placental cord insertion sites, lie of the donor twin, and size discordance enables preoperative prediction of key landmarks for successful FLOC.

Twin to twin transfusion syndrome

“…The procedure is typically performed between 16-26 weeks gestation using local anesthesia with intravenous sedation as needed, epidural or occasionally with general anesthesia (61,62). Preoperative ultrasound mapping of the placental cord insertions, intertwin membrane and consideration of fetal size discordance is used to estimate the location and orientation of the vascular equator (63). Using ultrasound guidance, the sac of the recipient fetus is entered with a fetoscope that has an outer trocar diameter of <4 mm.…”

Computer‐assisted fetal laser surgery in the treatment of twin‐to‐twin transfusion syndrome: Recent trends and prospects

“…Table 1 summarizes the purpose, anatomical structures of interest, and requirements in the preoperative and intraoperative phases 4,5 . Furthermore, the studies are categorized by the different steps in these phases; (1) imaging, (2) classification, (3) segmentation, (4) reconstruction, and (5) simulation 6 .…”

“…Table 1 summarizes the purpose, anatomical structures of interest, and requirements in the preoperative and intraoperative phases. 4,5 Furthermore, the studies are categorized by the different steps in these phases; (1) imaging, (2) classification, (3) segmentation, (4) reconstruction, and (5) simulation. 6 In this review, image segmentation refers to the technical process of (semi)automatical extraction of a region of interest by dividing the image into segments based on a specified description, such as vasculature detection.…”

Development of Robot-assisted Ultrasound System for Fetoscopic Tracking in Twin to Twin Transfusion Syndrome Surgery

“…To improve instrument localization, external 2D ultrasound (US) is employed [3]. However, a dedicated and experienced clinician is needed to manipulate the US pose.…”