ABSTRACT
Facial nerve (FN) injury is a significant risk during complex cranial reconstruction surgeries, especially in revision cases where normal anatomy is distorted. The authors introduce a technique to mitigate FN injury, including preoperative FN mapping, intraoperative FN mapping, and continuous FN monitoring. Preoperative mapping uses a handheld ball-tip stimulator to elicit compound muscle action potentials (CMAP) in the frontalis muscle. Needle electrodes are placed above the orbital margin to record responses, starting at the stylomastoid foramen and extending until the entire temporal branch is mapped. Intraoperatively, continuous mapping is achieved using an electrified insulated suction device, allowing dynamic mapping during soft tissue dissection. Continuous monitoring involves placing stimulation electrodes near the stylomastoid foramen and recording CMAP responses from the frontalis and orbicularis oculi/orbicularis oris muscles. The authors tested this technique in 5 patients. The authors successfully mapped the temporal branch of the FN with isolated frontalis CMAP recordings in all patients. Intraoperative FN mapping and continuous monitoring were successfully performed in all cases. Two patients experienced complete cessation of FN CMAPs, which resumed upon loosening the tension on the myocutaneous flap held by fishhooks. One patient showed a 39% decrement in frontalis CMAP that did not recover. Despite these issues, all patients had intact FN function postoperatively and at follow-up. Our technique shows promise in mitigating FN injury during complex cranial reconstruction and cranioplasty revision surgery. Further research with a larger cohort is needed to confirm efficacy and statistical significance.
ABSTRACT
STUDY OBJECTIVES: Advances in prenatal repair of myelomeningocele have improved outcomes involving different organ systems. There are limited data on respiratory outcomes following prenatal surgical repair. We hypothesize there is no difference in respiratory outcomes between patients with spina bifida who have undergone prenatal vs postnatal repair. METHODS: We performed a retrospective study of 46 infants < 1 year with spina bifida seen at Children's Hospital Los Angeles from 2004-2022. Demographic data, timing of closure, neonatal course, Chiari II malformation, ventriculoperitoneal shunt, polysomnography results, and need for supplemental oxygen were collected. Unpaired t test and χ2 test were used to analyze results. RESULTS: A total of 31/46 had prenatal repair of myelomeningocele; average age at repair was 27 weeks postconception. Average age at postnatal repair was 37 weeks postconception. There was no difference in age at polysomnography. There was no difference in Chiari II malformation presence (P = .61). Sixty pecent of patients with postnatal repair and 23% in the prenatal group underwent ventriculoperitoneal shunt placement (P = .01). There was no difference in polysomnography findings between the 2 groups: central apnea index (P = .11), obstructive apnea-hypopnea index (P = .64), average oxygen saturation baseline (P = .91), average oxygen saturation nadir (P = .17), average end-tidal carbon dioxide baseline (P = .87), and average end-tidal carbon dioxide maximum (P = .54). There were no significant differences in the proportion of patients on supplemental oxygen (P = .25), central sleep apnea or obstructive sleep apnea between groups. CONCLUSIONS: Patients with spina bifida who have undergone closure of neural tube defect have persistent central apneas, obstructive apneas, and significant hypoxemia. There were no differences in the frequency or severity of sleep-disordered breathing in those with prenatal repair vs postnatal repair. CITATION: Stark KG, Wang RY, Smith KA. Sleep-related breathing disorders in infants with spina bifida repaired prenatally and postnatally. J Clin Sleep Med. 2024;20(10):1579-1583.