Clinical and Histologic Evaluation of the Hysterotomy Site and Fetal Membranes after Open Fetal Surgery for Fetal Spina Bifida Repair

Abstract

Introduction: Among the risks associated with open fetal surgery, myometrium and fetal membrane issues are vexing problems since they may lead to uterine dehiscence or preterm premature rupture of membranes resulting in uterine rupture or preterm birth or both. The aim of this study was to examine whether stapled and sutured hysterotomy scars demonstrate partial or complete healing. Methods: Hysterotomy sites after open fetal surgery were clinically evaluated in 36 women during Caesarean section, classified into the categories intact, thin, and partially or completely dehiscent, then completely excised and histologically analyzed in 25 cases. The histological examination focused on wound healing of myometrium and fetal membranes. Results: The myometrium was intact, thin, and partially or completely dehiscent in 33, 58, and 9%, respectively. The interval between myelomeningocele repair and delivery did not correlate with the healing process. The myometrium showed a reparative zone (scar) with adjacent avital myometrium tissue, fibrosis, and inflammation with foreign body reaction. The intact myometrium was below 1 mm thickness in 56%. All fetal membranes showed complete dehiscence; in 41% they were completely avital. Conclusion: Our study provides evidence that the myometrium shows scarring with substantial thinning or dehiscence. Fetal membranes do not heal spontaneously. In order to prevent uterine rupture in subsequent pregnancies, we recommend the hysterotomy site to be completely excised after birth.

Fetal Surgery in the Primate 4.0: A New Technique 30 Years Later

“…The degree of histological inflammation and fibrosis of the hysterotomy scar observed in this study was similar to that produced with the stapler in both ovine and human studies [9,16]. The fibrosis was moderate and multifocal as seen with use of the AutoSuture Premium Poly CS*-57 stapler in the ovine model [9].…”

“…In this single animal, the fibrosis was more multifocal than the mild fibrosis that was largely limited to the region surrounding suture material in the ovine model [9]. Adhesions from adipose tissue on the serosa were visualized similarly to those seen with human stapled hysterotomy [16].…”

Systematic classification of maternal and fetal intervention‐related complications following open fetal myelomeningocele repair – results from a large prospective cohort

“…Despite the unequivocal benefits of open fMMC repair, there are specific intervention‐related maternal and fetal risks. These include oligohydramnios, chorioamniotic membrane separation, prelabour premature rupture of membranes (PPROM) and uterine scar dehiscence or rupture 1,3–6 . The latter leading to preterm delivery and eventual prematurity associated pathologies and intraoperative or postoperative bleeding 1 .…”

“…These include oligohydramnios, chorioamniotic membrane separation, prelabour premature rupture of membranes (PPROM) and uterine scar dehiscence or rupture. 1,[3][4][5][6] The latter leading to preterm delivery and eventual prematurity associated pathologies and intraoperative or postoperative bleeding. 1 Therefore, parental counselling must highlight the delicate balance between potential outcome benefits and risks for mother and fetus following open fMMC repair.…”

Prenatal regenerative fetoscopic interventions for congenital anomalies

“…Maternal risks included approximately 6% risk of pulmonary edema (attributed to use of tocolytics), 9% risk of blood transfusion at delivery, and need for a caesarean section for all future pregnancies, irrespective of other obstetric indications 163. Other studies have also found evidence of myometrium scarring and substantial thinning or dehiscence of the hysterotomy after open MMC repair 172. Tocolytics have been used preoperatively and postoperatively to minimize the risk of preterm birth after open MMC repairs 173…”