016. Effect of allograft patch closure upon incidence of spinal inclusion cysts following open fetal myelomeningocele repair

Authors: Sara Hartnett, MD

The formation of spinal inclusion cysts (sIC) is a known sequela of both pre- and post-natal repair of myelomeningocele (MMC). However, studies reporting the incidence of sIC in MMC are relatively scarce. It is unclear if the rates of sIC development and associated neurological findings are significantly different between pre- and post-natal repair, particularly as surgical techniques have evolved since the MOMS trial. The goal of this study was to report our institutional experience in patients who underwent open fetal MMC repair with a focus on elucidating the incidence of sIC formation.Methods: The authors conducted a retrospective review of patients who underwent open fetal MMC repair at our institution between March 2011 and June 2020. Outcomes included symptomatic and asymptomatic sIC formation. included the development of TCS and sIC formation.
Of the 56 patients included, six (11%) developed sIC that appeared to be associated with neurological findings. Six additional asymptomatic patients had evidence of sIC discovered on routine surveillance MRI. The overall incidence of sIC formation was 21%. When compared to patients without sIC development, there was a statistically significant difference in primary closure vs. the use of allograft patch at the level of the dura (p=0.003), while no difference was found at the levels of the fascia (p=0.47) or skin (p=0.51).
Our study is consistent with prior reports of higher incidence of sIC in children with prenatally-repaired MMC. In addition, sIC occurrence appeared to be influenced by use of dural allograft patches. Future investigations evaluating the incidence of sIC following fetoscopic MMC repair, in which dural patches are frequently employed given the technical difficulty of obtaining primary closure endoscopically, will be helpful in clarifying the etiology of sIC development as well as informing prenatal counseling for patients considering fetal intervention.