The Impact of Different Surgical Factors on the Extended Hospital Stay and Development of New Neurologic Deficits Following Resection of Intradural Intramedullary Spinal Cord Tumors

Introduction: Intramedullary spinal cord tumors(IMSCTs) are rare neoplasms whose treatment is often challenging. Given the low volume seen at most centers and the broad surgical expertise, it is still unknown if surgical factors engender more extended hospital stays(HS) and postoperative neurologic deficits. We aimed to present our institutional series of IMSCTs, focusing on clinical presentation and perioperative outcomes. We also investigated surgical factors impacting the upper quartile(Q3-HS) and postoperative neurologic deficit.

Methods: We retrospectively identified all patients operated on for primary IMSCTs at our center between January 2017 and September 2022. Data was collected on patient demographics, tumor histology,location,grade,symptoms and operative characteristics. Perioperative outcomes included postoperative neurologic deficit,Q3-HS,early( < 30 days)readmission and reoperation. Logistic regression and Random Forest classifiers were trained and tested to predict Q3-HS(≥6 days) and postoperative neurologic deficit using 80/20 data split. Minimal depth using was calculated to classify surgical factors by importance in predicting both outcomes.

Results: One hundred forty-five patients were included in the study (mean age 42.68 ±7.4years,87.6% white,50.3% males). The most common tumors were ependymomas(44.8%),hemangioblastomas(30.3%) and astrocytomas(24.8%). The majority of tumors were grade II(43%) localized in the cervical (40.3%) and thoracic cord(30.6%). Most patients had sensory changes(88.3%) and lower extremity weakness(66.2%). Most patients had 3-4 bony levels removed(44.8%) and 15.9% underwent fusion. Multivariable regression shows that laminectomy of 1-2 levels was more likely to decrease the risk of Q3-HS. Minimal depth analysis showed that Q3-HS was significantly affected by the number of laminectomy levels; fusion levels; type of resection and duraplasty. Postoperative neurologic deficit was affected by the number of laminectomy levels, type of resection, location of surgery, duraplasty, and fusion levels.

Conclusion : Multiple surgical factors affect the longer hospital stay (≥6 days) and the development of a novel postoperative neurologic deficit with the extension of laminectomy levels being the top factor influencing the risk of both outcomes.