Amniotic Membrane Interposition Graft for Open Fetal Myelomeningocele Repair

Myelomeningocele (MMC) is a congenital anomaly frequently leading to motor deficits, urological dysfunction, and hydrocephalus. Fetal surgical repair improves motor function and reduces the need for cerebrospinal fluid diversion for hydrocephalus. One complication of MMC repair is spinal cord tethering at the site of surgical repair. Surgical techniques to reduce symptomatic tethering and achieve optimal motor function are an area of ongoing research. This study's objective is to evaluate a technique for interposing an amniotic membrane graft between the pia of the closed placode and the overlying dural closure in a prospectively treated cohort of patients with open fetal MMC closure. The theoretical advantage of this technique is that an amniotic membrane barrier may reduce the likelihood of tethering between surgically closed layers.

Under an approved, prospective protocol, open fetal MMC repair with an amniotic membrane interposition graft was performed by a single surgeon at 1 institution over a 1-year period. At the time of surgery, amniotic membrane was harvested from the edges of hysterotomy. This membrane was cleaned, trimmed, and secured over the closed pial surface of the repaired placode. The dura and overlying layers were closed in a standard fashion. Outcomes were obtained by interviews with patients' families.

Open fetal MMC repairs were performed with amniotic membrane graft interposition. One of 8 patients with a 5-year follow-up subsequently underwent spinal cord detethering surgery.

Amniotic patch interposition for fetal MMC repair can be performed safely alongside standard MMC repair techniques. Evidence for effectiveness on rates of subsequent detethering surgeries requires larger studies with longer follow-up.