Intraoperative recurrent laryngeal nerve monitoring during video-assisted throracoscopic surgery for patent ductus arteriosus.

OBJECTIVE: To develop a technique to identify and localize the recurrent laryngeal nerve (RLN) during video-assisted thoracoscopic surgery (VATS) for patent ductus arteriosus. DESIGN: Prospective clinical study. SETTING: Children's hospital. PARTICIPANTS: Sixty infants and children scheduled for elective closure of patent ductus arteriosus. INTERVENTIONS: With parental informed consent, 60 infants and children undergoing elective VATS for patent ductus arteriosus were studied. A thin, pencil-point, Teflon-coated, stimulating probe allowed direct stimulation (<2 mA, 100-msec pulse width) of the left RLN inside the thorax. A commercially available 4-channel neurologic monitor recorded compound evoked electromyograms (EMGs) from the left RLN and right RLN (as control) by needle electrodes placed percutaneously in the neck. Hoarseness, stridor, feeding difficulties, and voice changes were assessed postoperatively. MEASUREMENTS AND MAIN RESULTS: Left RLN EMGs were easily obtained in 59 of the 60 patients. The surgeon correctly identified the RLN visually once in the first 7 patients; this ability subsequently improved. EMG localization of the location or course of the RLN altered dissection, clip size, or clip position in 37 of 59 patients. CONCLUSION: Intraoperative EMG to identify location and route of the RLN was easy to perform, was effective in identifying RLN position, and appeared to facilitate dissection and clipping of the ductus.

SSEP monitoring during pelvic and acetabular fracture surgery.

Forty-one consecutive patients requiring surgery for pelvic or acetabular fractures were reviewed to compare the 20 patients (20 fractures) who had SSEP monitoring to the twenty-one patients (22 fractures) in whom monitoring was not available. In the unmonitored group, five patients had a preoperative neurologic deficit (three major/two minor), whereas in the monitored group there were nine patients with deficits (two major/seven minor). Intraoperatively, significant somatosensory evoked potential (SSEP) changes occurred in six of the monitored patients. In five patients the changes resolved on correction of the offending action and there was no postoperative deficit. In the remaining case, SSEP changes did not resolve and the patient awoke with a peroneal palsy. This one monitored patient with a new deficit compares with five patients with postoperative new deficits (or deteriorations) in the unmonitored group. The majority of intraoperative SSEP changes and iatrogenic deficits occurred during surgery through the ilioinguinal approach. During follow-up, the great majority of deficits resolved completely or had significant improvement.

Somatosensory evoked potential monitoring during Cotrel-Dubousset instrumentation. Report of a case.

Somatosensory evoked potentials produced by electrical stimulation of the posterior tibial nerve were recorded from surface electrodes at the scalp and cervical spine of a patient with scoliosis undergoing posterior spinal fusion with Cotrel-Dubousset instrumentation. During spinal derotation when hypotension and anemia were also present, the cortical and subcortical somatosensory evoked potentials disappeared. During a wake-up test, the patient demonstrated weakness of the left lower extremity, and derotation was stopped. The patient was given pharmacologic hypertensive agents and blood transfusions to increase blood pressure. Forty minutes later, somatosensory evoked potentials returned and a second wake-up test demonstrated normal function in both lower extremities. This report demonstrates the accuracy and usefulness of somatosensory evoked potential monitoring during spinal fusion with Cotrel-Dubousset instrumentation. To the authors knowledge, this is the first report demonstrating a correlation between abnormal SEP responses and intraoperative neurologic deficit during the derotation maneuver with Cotrel-Dubousset instrumentation and corrected by transfusion and restoration of normotension.

Comparison and correlation of surface and sphenoidal electrodes with simultaneous intracranial recording: an interictal study.

We prospectively compared and correlated interictal spikes recorded with simultaneous surface, sphenoidal, depth and subdural electrodes in 21 patients. Although the amplitude of sphenoidal spikes was often larger than that of surface spikes in patients with mesial basal temporal ictal and interictal foci, only 1 patient had exclusively sphenoidal spikes. Spikes with maximal amplitude at the sphenoidal electrode arose from mesial temporal, temporal neocortical and orbital frontal foci. An inferior vertical temporal dipole (hippocampal positive and inferior temporal neocortex negative) was associated with surface and sphenoidal spikes.