OBJECT The authors report their experience with the use of a minimally invasive hemilaminectomy approach for the excision of intradural extramedullary (IDEM) tumors of the spinal cord. METHODS Included were 164 consecutive patients (167 tumors in total), treated between January 2004 and December 2014, in whom the hemilaminectomy approach for IDEM spinal cord tumors was planned. The clinicoradiological data of patients presenting to Christian Medical College were analyzed retrospectively using a computerized chart-review method. Preoperative MRI localization was used in 51 cases. RESULTS The mean age (± SD) of the patients was 42.6 ± 16.6 years, and the mean duration of symptoms was 20.8 ± 27.8 months. The average tumor size was 2.4 ± 1.7 cm. Forty-four tumors were cervical, 5 were cervicothoracic, 72 were thoracic, 7 were thoracolumbar, and 39 were lumbar. Forty-two tumors were ventrally located, whereas 11 were ventrolateral; the rest were either dorsal or dorsolateral. The most common pathologies were schwannoma (110 cases) and meningioma (31 cases). Total excision was achieved for 93% of the tumors. The average duration of surgery was 1.6 ± 0.6 hours. CONCLUSIONS The hemilaminectomy approach to the removal of intradural tumors was quick and safe and resulted in minimal morbidity and no mortality. Preoperative MRI localization improved accuracy and reduced operating time by eliminating the need for intraoperative fluoroscopy.
Keywords: IDEM = intradural extramedullary; MEP = motor evoked potential; MMEP = myogenic MEP; extramedullary; hemilaminectomy; intradural; spine; tumor.