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

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.