"This is how we do it" Maternal and fetal anesthetic management for fetoscopic myelomeningocele repairs: the Texas Children's Fetal Center protocol

Abstract

Prenatal repair of myelomeningocele (MMC) is associated with lower rates of hydrocephalus requiring ventriculoperitoneal shunt and improved motor function when compared with postnatal repair. Efforts aiming to develop less invasive surgical techniques to decrease the risk for the pregnant patient while achieving similar benefits for the fetus have led to the implementation of fetoscopic surgical techniques. While no ideal anesthetic technique for fetoscopic MMC repair has been demonstrated, we present our anesthetic approach for these repairs, including considerations for both the pregnant patient and the fetus. We emphasize the importance of the preoperative consultation to optimize any medical conditions and to set expectations for the perioperative course. Our preferred anesthetic technique for the pregnant patient includes general anesthesia with an epidural for postoperative analgesia. Intraoperative anesthetic considerations for patients undergoing fetoscopic surgery include tocolysis, meticulous control of hemodynamics, judicious fluid administration, and maternal temperature regulation. We also avoid long-acting neuromuscular blocking agents due to significant weakness observed when given in combination with magnesium sulfate. While the maternal anesthetic crosses the placenta, direct administration of anesthesia to the fetus is required to reliably blunt the stress response. Additional considerations for the fetus include monitoring, fetal resuscitation strategies, and the theoretical risk of anesthetic neurotoxicity. Postoperatively, we use a multi-modal, opioid sparing regimen for analgesia. As advances in fetal surgery aiming to minimize risk to the pregnant patient alter the surgical approach, maternal-fetal anesthesiologists must adapt and incorporate the unique considerations of fetoscopy into their anesthetic management.

Keywords: Anesthesia; Fetal surgery; Fetoscopy; Myelomeningocele; Protocol; Spina bifida.