MRI-guided frameless stereotactic percutaneous cordotomy

Background: Use of intraoperative myelography as a radiologic guidance for percutaneous cervical cordotomy (PCC) has been superseded by more modern imaging. The only significant advancement in cordotomy techniques over the last 30 years has been CT-guided PCC. The goal of this study was to demonstrate the feasibility of an MRI-guided frameless technique in high cervical cordotomy.

Methods: We describe 6 patients with intractable pain treated using a frameless, MRI-guided, stereotactic, PCC technique in combination with standard physiological localization procedures. Results were compared with those from 32 patients who underwent PCC in the last 5 years using physiological localizing techniques only.

Results: Six patients (100%) who underwent the frameless technique had excellent pain relief postoperatively. Patients in the non-stereotactic group, on average, required a higher number of lesions (2.5 vs. 1.2, p < 0.005), and 7 (22%) of these patients had unsatisfactory pain relief following PCC (p = 0.21). Five patients in the non-stereotactic group had weakness postoperatively and 1 had changes in bladder function. Postoperative weakness occurred in 1 patient undergoing the frameless technique. At an average of 6 months of follow-up (range 5-11), excellent pain relief was achieved in 83% (5/6) of MRI frameless PCC patients and 55% (16/29) of standard PCC patients (p = 0.20).

Conclusions: Intraoperative frameless stereotaxy provides surgeons with accurate information that helps to guide the operative approach and precisely tailor the trajectory and depth of the electrode, potentially increasing the safety and efficacy of the operation.