Detailed analysis of cystic lesions in patients after open fetal repair and postnatal myelomeningocele closure.

Purpose: We sought to evaluate the incidence, natural history, and management of cystic spinal lesions following myelomeningocele/myeloschisis closure.

Methods: We performed a single-center retrospective review of all patients who underwent myelomeningocele/myeloschisis closure from 2013 to 2018 with follow-up to 5 years old.

Results: We analyzed 100 fetal repairs and 81 postnatal closures from 305 total surgeries. Patients within this cohort systematically underwent serial MRI scans of the lumbar spine and had clinical follow-up until at least 5 years of age. Ninety-three (51.2%) developed radiographic evidence of cystic lesions with 28 (30.1%) requiring surgical intervention. Presence of cysts was higher in fetal repair (67/100, 67%) compared with postnatal (26/81, 32.1%; p < 0.01). Of the 93 patients with radiographic cysts, 28 (30.1%) underwent surgical resection at a median age of 27.6 months old ([Q1, Q3], [13.0, 48.6 months]). Fetal repair patients had a higher rate (26/67, 38.8%) of cysts requiring surgical resection compared with postnatal closure (2/26, 7.7%, p value < 0.01). Pathology demonstrated 18 of resected cysts were dermoid, 8 were epidermoid, and 2 were fibrous tissue. Post-operatively, no patients experienced a worsened ambulation status. Bladder compliance showed a non-significant trend toward improvement.

Conclusions: Cystic lesions in myelomeningocele/myeloschisis patients are common findings that result in nerve root tethering. We propose regular screening in both symptomatic and asymptomatic patients to circumvent nerve injury. Most cystic lesions do not require surgical resection though fetal repair is associated with a higher incidence of operative cysts. However, these lesions can be safely surgically resected with maintenance of ambulation and urologic function.