Intramedullary Spinal Neoplasms Research Articles

Agreement and differentiation of intradural spinal cord lesions in dogs using magnetic resonance imaging.

BackgroundMagnetic resonance imaging is the method of choice for diagnosing spinal cord neoplasia, but the accuracy of designating the relationship of a neoplasm to the meninges and agreement among observers is unknown.ObjectivesTo determine agreement among observers and accuracy of diagnosis compared with histology when diagnosing lesion location based on relationship to the meninges.AnimalsMagnetic resonance images from 53 dogs with intradural extramedullary and intramedullary spinal neoplasms and 17 dogs with degenerative myelopathy.MethodsSix observers were supplied with 2 sets of 35 images at different time points and asked to designate lesion location. Agreement in each set was analyzed using kappa (κ) statistics. We tabulated total correct allocations and calculated sensitivity, specificity, and likelihood ratios for location designation from images compared with known histologic location for lesions confined to 1 location only.ResultsAgreement in the first set of images was moderate (κ = 0.51; 95% confidence interval [CI], 0.43‐0.58) and in the second, substantial (κ = 0.69; 95% CI, 0.66‐0.79). In the accuracy study, 180 (75%) of the 240 diagnostic calls were correct. Sensitivity and specificity were moderate to high for all compartments, except poor sensitivity was found for intradural extramedullary lesions. Positive likelihood ratios were high for intradural extramedullary lesions and degenerative myelopathy.Conclusions and Clinical ImportanceOverall accuracy in diagnosis was reasonable, and positive diagnostic calls for intradural extramedullary lesions and negative calls for intramedullary lesions are likely to be helpful. Observers exhibited considerable disagreement in designation of lesions relationship to the meninges.

Minimally Invasive Approach for the Resection of Spinal Neoplasm

Retrospective Case Series. To determine if extradural, intradural extramedullary, and intramedullary spinal neoplasms can be safely resected through a minimally invasive corridor. The use of minimally invasive approaches for resection of spinal neoplasms has been described for intradural schwannomas and ependymomas. We demonstrate that this approach can be extended to the resection of a variety of extradural, intradural and intramedullary spinal tumors. We undertook a retrospective review of all patients presenting with clinical and radiographic evidence of spinal neoplasm that subsequently underwent a minimally invasive approach for resection of the tumor using the METRx MAST QUADRANT Retractor System (Medtronics, Memphis, TN). Primary endpoints analyzed include completeness of resection, postoperative neurologic status, operative time, blood loss, postoperative pain, length of hospital stay, and operative complications. Two cervical, seven thoracic and 13 lumbar neoplasms were identified in 20 patients operated on between September 2005 and May 2009. Mean intraoperative time was 210 minutes, blood loss 428 mL and average length of hospital stay was 3 days. Four patients required postoperative patient-controlled analgesia for pain control and an average of 5.8 doses of narcotic were given per patient. Two patients developed postoperative complications. Fifteen of 22 tumors (68%) were completely resected, with only one patient requiring repeat operation for residual tumor. All but one patient were improved from preoperative status at 6 months. Intramedullary, intradural and extradural spinal neoplasms can be resected through a minimally invasive approach without increased risk for adverse neurologic outcome. This technique may be an appropriate alternative to the open approach for well-circumscribed extramedullary lesions spanning one or two spinal levels. With increasing experience, reduced operative time, blood loss, complications, length of hospital stay, postoperative pain, and spinal instability may be seen.