Intraoperative neuromonitoring: lessons learned from 32 case events in 2095 spine cases

摘要

>Study type: Restrospective chart review>Introduction: Intraoperative neuromonitoring is becoming the standard of care for many more spinal surgeries, especially with deformity correction and instrumentation. We reviewed our institution's neuromonitored spine cases over the past 4 years to see the immediate intraoperative and postoperative clinical findings when an intraoperative neuromonitoring event was noted.>Objective: The main question addressed in this review is how multimodality intraoperative neuromonitoring has affected our ability to avoid potential neurological injury during spine surgery.>Methods: We retrospectively reviewed 2,095 neuromonitored spine cases at one institution performed over a period of 4 years. Data from the single neuromonitoring provider (Impulse Monitoring, Inc.) at our institution was collected and any cases with possible intraoperative events were isolated. The intraoperative and immediate postoperative clinical documentation of these 32 cases were reviewed ().>Table 1>Summary of each case event with the type of procedure, intraoperative findings, intraoperative intervention, and postoperative findings rules="all" class="rendered small default_table">>CaseProcedureIntraoperative findingsIntraoperative interventionPostoperative findings> valign="top" align="left" rowspan="1" colspan="1">1 valign="top" align="left" rowspan="1" colspan="1">Posterior cervical decopression valign="top" align="left" rowspan="1" colspan="1">Loss of MEP valign="top" align="left" rowspan="1" colspan="1">Increased blood preasure valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">2 valign="top" align="left" rowspan="1" colspan="1">Cervicothoracic spinal cord lesion biopsy valign="top" align="left" rowspan="1" colspan="1">Loss of MEP in lower extremities valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Bilateral lower extremity paresis> valign="top" align="left" rowspan="1" colspan="1">3 valign="top" align="left" rowspan="1" colspan="1">Thoracic spinal cord tumor debulking valign="top" align="left" rowspan="1" colspan="1">Loss of MEP in right lower extremity valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Right lower extremity paralysis> valign="top" align="left" rowspan="1" colspan="1">4 valign="top" align="left" rowspan="1" colspan="1">Posterior lumbosacral decompression/fusion TLIF valign="top" align="left" rowspan="1" colspan="1">Low S1 screw threshold valign="top" align="left" rowspan="1" colspan="1">Screw checked, repositioned valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">5 valign="top" align="left" rowspan="1" colspan="1">Posterior lumbar decompression/fusion valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Foot drop, medial L4 screw breach> valign="top" align="left" rowspan="1" colspan="1">6 valign="top" align="left" rowspan="1" colspan="1">Cervicomedullary spinal cord tumor resection valign="top" align="left" rowspan="1" colspan="1">Loss of left upper extremity SSEP valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Left upper extremity sensory deficit> valign="top" align="left" rowspan="1" colspan="1">7 valign="top" align="left" rowspan="1" colspan="1">Anterior thoracic discectomies/partial corpectomies valign="top" align="left" rowspan="1" colspan="1">Left upper extremity decreased SSEP valign="top" align="left" rowspan="1" colspan="1">Carm pressing on arm, removed valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">8 valign="top" align="left" rowspan="1" colspan="1">Posterior lumbosacral decompression/fusion TLIF valign="top" align="left" rowspan="1" colspan="1">Right upper extremity decreased SSEP valign="top" align="left" rowspan="1" colspan="1">Arm repositioned valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">9 valign="top" align="left" rowspan="1" colspan="1">C7–T1 anterior decompression/fusion valign="top" align="left" rowspan="1" colspan="1">Right lower extremity decreased MEP valign="top" align="left" rowspan="1" colspan="1">Increased blood preasure valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">10 valign="top" align="left" rowspan="1" colspan="1">T11–L5 anterior discectomy/fusion valign="top" align="left" rowspan="1" colspan="1">Right lower extremity decreased SSEP, MEP valign="top" align="left" rowspan="1" colspan="1">Increased blood preasure valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">11 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar decompression/fusion TLIF valign="top" align="left" rowspan="1" colspan="1">Left lower extremity decreased SSEP valign="top" align="left" rowspan="1" colspan="1">Increased blood preasure valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">12 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar decompression/fusion costotransversectomy T11, T12, L1 partial vertebrectomies valign="top" align="left" rowspan="1" colspan="1">Right lower extremity decreased SSEP, MEP valign="top" align="left" rowspan="1" colspan="1">Stopped procedure, stage 1 of 2 valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">13 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar decompression/fusion TLIF valign="top" align="left" rowspan="1" colspan="1">Variable SSEP, MEP valign="top" align="left" rowspan="1" colspan="1">Labile blood preasure valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">14 valign="top" align="left" rowspan="1" colspan="1">Posterior occipitocervical decompression/fusion valign="top" align="left" rowspan="1" colspan="1">Right upper extremity decreased SSEP valign="top" align="left" rowspan="1" colspan="1">Positioning effect, arm tucked valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">15 valign="top" align="left" rowspan="1" colspan="1">Anterior thoracic osteotomies valign="top" align="left" rowspan="1" colspan="1">Right lower extremity loss of SSEP after graft placement valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">16 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar decompression/fusion TLIF valign="top" align="left" rowspan="1" colspan="1">Right lower extremity loss MEP, SSEP stable valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">17 valign="top" align="left" rowspan="1" colspan="1">Anterior cervical corpectomy and fusion valign="top" align="left" rowspan="1" colspan="1">No baseline SSEPs valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Improved SSEPs> valign="top" align="left" rowspan="1" colspan="1">18 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar decompression/fusion PSO valign="top" align="left" rowspan="1" colspan="1">Bilateral lower extremity SSEPs decreased with rod placement valign="top" align="left" rowspan="1" colspan="1">Rods placed, baseline SSEPs returned valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">19 valign="top" align="left" rowspan="1" colspan="1">T7 spinal cord tumor resection valign="top" align="left" rowspan="1" colspan="1">Loss of bilateral lower SSEPs (no MEPs present at baseline) valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">No change from preoperative function> valign="top" align="left" rowspan="1" colspan="1">20 valign="top" align="left" rowspan="1" colspan="1">Posterior then anterior cervicothoracic fusion valign="top" align="left" rowspan="1" colspan="1">Decreased SSEPs post flip valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">21 valign="top" align="left" rowspan="1" colspan="1">Anterior thoracolumbar decompression/fusion valign="top" align="left" rowspan="1" colspan="1">Thoracotomy, left upper extremity (down arm) loss SSEPs valign="top" align="left" rowspan="1" colspan="1">Repositioned, large pt, procedure shortened valign="top" align="left" rowspan="1" colspan="1">Transient sensory changes> valign="top" align="left" rowspan="1" colspan="1">22 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar decompression/fusion TLIF valign="top" align="left" rowspan="1" colspan="1">Right lower extremity loss of MEP valign="top" align="left" rowspan="1" colspan="1">Needle repositioned, signals reacquired valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">23 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracic fusion valign="top" align="left" rowspan="1" colspan="1">Bilateral lower extremity loss of MEP with distraction valign="top" align="left" rowspan="1" colspan="1">Variable signal changes, returned to baseline valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">24 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar deformity correction with fusion valign="top" align="left" rowspan="1" colspan="1">Left lower extremity decreased SSEP, loss of MEP during correction valign="top" align="left" rowspan="1" colspan="1">Correction held, increased blood pressure valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">25 valign="top" align="left" rowspan="1" colspan="1">Posterior cervicothoracic deformity correction with fusion valign="top" align="left" rowspan="1" colspan="1">Bilateral lower extremity loss of MEP, deacreased SSEPs valign="top" align="left" rowspan="1" colspan="1">Correction decreased valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">26 valign="top" align="left" rowspan="1" colspan="1">Posterior lumbosacral decompression/fusion valign="top" align="left" rowspan="1" colspan="1">Low screw threshould valign="top" align="left" rowspan="1" colspan="1">No breach, screw replaced valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">27 valign="top" align="left" rowspan="1" colspan="1">Posterior lumbosacral decompression/fusion TLIF valign="top" align="left" rowspan="1" colspan="1">None, spontaneous EMG only valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Screw in canal> valign="top" align="left" rowspan="1" colspan="1">28 valign="top" align="left" rowspan="1" colspan="1">Posterior lumbar decompression/fusion valign="top" align="left" rowspan="1" colspan="1">None, spontaneous EMG only valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Foot drop, medial left L4screw breach> valign="top" align="left" rowspan="1" colspan="1">29 valign="top" align="left" rowspan="1" colspan="1">Posterior thoracolumbar deformity correction with fusion valign="top" align="left" rowspan="1" colspan="1">Bilateral lower extremity loss of MEP valign="top" align="left" rowspan="1" colspan="1">Decreased correction valign="top" align="left" rowspan="1" colspan="1">No deficit> valign="top" align="left" rowspan="1" colspan="1">30 valign="top" align="left" rowspan="1" colspan="1">Anterior cervical corpectomy and fusion valign="top" align="left" rowspan="1" colspan="1">Improved MEP after decompression valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Improved function> valign="top" align="left" rowspan="1" colspan="1">31 valign="top" align="left" rowspan="1" colspan="1">Anterior thoracic discectomy and fusion valign="top" align="left" rowspan="1" colspan="1">Improved MEP after decompression valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Improved function> valign="top" align="left" rowspan="1" colspan="1">32 valign="top" align="left" rowspan="1" colspan="1">Anterior cervical corpectomy and fusion valign="top" align="left" rowspan="1" colspan="1">Improved MEP after decompression valign="top" align="left" rowspan="1" colspan="1">None valign="top" align="left" rowspan="1" colspan="1">Improved function>Results: There were 17 cases where changes noted on EMG, SSEP, and/or MEPs affected the course of the surgery, and prevented possible postoperative neurological deficits. Of these 17, five were related to hypotension, seven due to deformity correction, one screw had a low triggered EMG threshold and was repositioned, and four cases had changes related to patient positioning and external pressure (ie, brachial plexus stretch). None of the 17 cases had postoperative motor or sensory deficits (). During the insertion of the convex rod: decrease of the MEP amplitude in left foot by 80% amplitude (yellow arrow). The baseline recording is in blue, the current recording in purple. The right side (non represented) will remain normal.