O2132: Analysis of 5317 Consecutive Pediatric Spinal Deformity Intraoperative Neuromonitoring (IONM) Alerts: Importance of Normotension at Correction and IONM Recovery

Background: Spinal cord dysfunction after pediatric spinal deformity is a potentially devastating complication. Use of intraoperative multimodal neuromonitoring (IONM) to monitor sensory and motor tracts decreases the frequency of postoperative spinal cord dysfunction by facilitating corrective actions and is considered standard of care. However, there is little information regarding the timing of alerts during surgery or on the specific maneuvers used to recover IONM data to baseline. The purpose of this study is to identify the chronology of IONM alerts during pediatric spinal deformity surgery, corrective maneuvers, and the short-term and final neurological outcomes.

Methods: An institutional neuromonitoring database was reviewed (11/1992 to 4/2024) to identify all consecutive patients (0–18 yrs) undergoing pediatric spine deformity surgery at one of our three tertiary-care hospitals, with at least one IONM alert.

Results: A total of 223 patients (4.2%) were identified out of 5317 consecutive cases, whose chronology are detailed in Figure 1. There were 347 corrective actions. Correction of hypotension was the most common action, used in 93 cases (42%), followed by adjustment of deformity correction. Among all alerts, 74 had documentation of MAP at the time of the alert (66.5+/-13.4 mmHg) and 61 had documentation at resolution (86.3+/-12.5 mmHg). Postoperative neurologic change was observed in 34 patients (15.2%). Worst-case scenario, persistent neurologic change, occurred in 5.8% (13/223). 160 patients had data recovery intraoperatively: 150 (94%) awoke w/ normal exam, and 157 (98%) had no change from preoperative neurological status at final follow-up. 63 patients did not have data recovery: 39 (62%) awoke with normal exam, and 53 (84%) had no change from preoperative neurological status at final follow-up. A significant association existed between both immediate and final neurologic outcomes and the return of data before surgery completion (p < 0.001). Overall, at wake-up, 0.6% had neurologic change and worst-case scenario was 0.24% (13/5317) at final neurologic exam.

Conclusion: In this largest single-center experience with IONM of 5317 consecutive pediatric spinal deformity surgeries, IONM alerts occurred in 4.2% of cases, of which 15.2% had neurological change from baseline at conclusion of surgery. The most common time for alerts was associated with correction (42%, n=99) and most common corrective action was correction of hypotension (42%, n=93). Intraoperative corrective actions after an IONM alert potentially decreased spinal cord dysfunction from 4.2% intraoperatively, to 0.6% at wake-up, to 0.24% (13/5317) at final exam. This study supports the use of an IONM alert protocol to optimize outcomes and enable optimal preoperative shared-decision making.