Proof of concept testing of a vascular closure device for use in fetal surgery.

Abstract

Objective: Prior clinical findings have demonstrated that maternal laparotomy with trans-amniotic trans-uterine suturing of the fetoscopic port site during in utero myelomeningocele repair reduces the risk of membrane rupture. However, due to laparotomy-associated morbidity, we aimed to explore the feasibility of using a vascular closure device for percutaneous trans-amniotic trans-uterine suturing.

Methods: This IRB and IACUC-exempt study utilized 2 strategies for proof-of-concept testing of using the Abbott Perclose^™ ProStyle^™ Device for suture placement; 1. Ultrasound guided application on a high fidelity maternal abdominal uterus model used for fetal procedures and 2. Placement under direct visualization with sheep undergoing cesarean delivery for other research purposes. In the high-fidelity uterus model, the Abbott Perclose^™ ProStyle^™ device was used to place a transuterine/transamniotic stitch with accompanying video recording of the approach (https://go.screenpal.com/watch/cZfhoDVsYvW password: perclose). Regarding the second approach, at the time of a cesarean section, 12 French Checkflo^® cannulas were inserted into the sheep amniotic space via different approaches: (1) Seldinger technique, (2) Seldinger technique insertion of Checkflo^® cannula and subsequent use of the Abbott Perclose^™ ProStyle^™ device to suture the port site after check flow removal, (3) Abbott Perclose^™ ProStyle^™ device utilized in what is described as a "pre-close" technique, where prior to cannula placement, trans-uterine trans-amniotic stitches are placed followed by the insertion of a 12 French Checkflo^® cannula over the same guidewire. Samples of the sutured uterine wall were sent to pathology and H&E staining was performed to assess uterine hole closure and amnion-to-uterus fixation.

Results: The high-fidelity model confirmed that the Perclose^™ ProStyle^™ Device was easily visualized by ultrasound and suture deployment was without complication. In the animal model, the Perclose^™ ProStyle^™ device effectively sutured the amnion to the uterus in both the pre- and post-close approach. The pre-close technique achieved better amnion-to-uterus approximation and more appropriate uterine hole closure. H&E staining revealed that without suturing, amnion separation from the chorion layer occurred, and the uterine hole persisted. The post-close technique showed partial connection between the amnion and chorion, but inadequate uterine hole closure with amnion shift into the defect. Optimal closure, with secure amnion-to-chorion fixation and uterine closure, was achieved through the pre-close technique.

Conclusion: The Abbott Perclose^™ ProStyle^™ Device seems to be a feasible device for use of uterine port closure in maternal-fetal surgery, larger animal studies with mid-pregnancy application are needed to further validate or refute these findings.