Image Merge Tailored Access Resection (IMTAR) for Intradural Extramedullary Tumors: A Retrospective Series of Eight Cases

Introduction: Posterolateral approaches are the standard surgical procedures for intradural extramedullary tumors (IDEM). These approaches carry a significant risk of developing postoperative deformity and they allow a limited access to ventrally located lesions. In the present series, we report our experience of eight patients using the image merge tailored access resection (IMTAR) technique, which integrates preoperative MRI data and intraoperative three-dimensional (3D) fluoroscopic images for minimally invasive spine surgery (MISS) of IDEM. Methods: Patients operated for IDEM tumors using IMTAR were selected. Preoperative MRI and intraoperative 3D fluoroscopic data were manually merged. Skin incision was planned according to the chosen entry point and the transmuscular trajectory was optimized for tumor access. Tailored bone resection and lesion removal were performed with standard microsurgical techniques. Results: From December 2012 to September 2014, eight patients were treated for IDEM tumors with IMTAR, five males and three females. MISS was integrated with Image Merged guidance. The median age was 49.1 years (range: 19–68). There was no neurologic deterioration in postoperative period. The postoperative follow-up ranged from 7 to 15 months (average 10.7 months). Neurological examination was normal with complete resolution of preoperative symptoms in six out of the eight patients. Postoperative MRI in all cases confirmed GTR. Conclusions: IMTAR is a novel MISS technique for patients with intradural extramedullary tumors. This technique permits tailored surgical approach with less neural structures manipulation and minimal bone removal while achieving complete tumor resection.