Claudio E. Tatsui, Ganesh Rao, and Laurence D. Rhines
Ganesh Rao, Adam S. Arthur, and Ronald I. Apfelbaum
✓ Fractures of the craniocervical junction are common in victims of high-speed motor vehicle accidents; indeed, injury to this area is often fatal. The authors present the unusual case of a young woman who sustained a circumferential fracture of the craniocervical junction. Despite significant trauma to this area, she suffered remarkably minor neurological impairment and made an excellent recovery. Her injuries, treatment, and outcome, as well as a review of the literature with regard to injuries at the craniocervical junction, are discussed.
Jonathan G. Thomas, Ganesh Rao, Yvonne Kew, and Sujit S. Prabhu
Glioblastoma (GBM) is the most common and deadly malignant primary brain tumor. Better surgical therapies are needed for newly diagnosed GBMs that are difficult to resect and for GBMs that recur despite standard therapies. The authors reviewed their institutional experience of using laser interstitial thermal therapy (LITT) for the treatment of newly diagnosed or recurrent GBMs.
This study reports on the pre-LITT characteristics and post-LITT outcomes of 8 patients with newly diagnosed GBMs and 13 patients with recurrent GBM who underwent LITT.
Compared with the group with recurrent GBMs, the patients with newly diagnosed GBMs who underwent LITT tended to be older (60.8 vs 48.9 years), harbored larger tumors (22.4 vs 14.6 cm3), and a greater proportion had IDH wild-type GBMs. In the newly diagnosed GBM group, the median progression-free survival and the median survival after the procedure were 2 months and 8 months, respectively, and no patient demonstrated radiographic shrinkage of the tumor on follow-up imaging. In the 13 patients with recurrent GBM, 5 demonstrated a response to LITT, with radiographic shrinkage of the tumor following ablation. The median progression-free survival was 5 months, and the median survival was greater than 7 months.
In carefully selected patients with recurrent GBM, LITT may be an effective alternative to surgery as a salvage treatment. Its role in the treatment of newly diagnosed unresectable GBMs is not established yet and requires further study.
Brian J. Williams, Patrick J. Karas, Ganesh Rao, Laurence D. Rhines, and Claudio E. Tatsui
The authors present the first report of laser interstitial thermal therapy (LITT) ablation of a recurrent chordoma metastasis to the cervical spine. This patient was a 75-year-old woman who was diagnosed and treated for a sacral chordoma, and then developed metastases to the lung and upper thoracic spine. Unfortunately she experienced symptomatic recurrence at the C-7 spinous process. She underwent an uncomplicated LITT to the lesion. The patient convalesced without incident and was discharged on postoperative Day 1. She received stereotactic spinal radiosurgery to the lesion at a dose of 24 Gy in 1 fraction. At the 3-month follow-up evaluation she had radiographic response and improvement in her symptoms.
Benjamin D. Fox, Akash Patel, Dima Suki, and Ganesh Rao
Metastatic sarcoma to the brain is rare and represents a therapeutic challenge due to its relative resistance to radio- and chemotherapy. Resection has traditionally been the mainstay of treatment. The authors reviewed a series of patients with metastatic sarcoma to the brain treated surgically to determine outcomes and identify predictors of survival in these patients.
A retrospective review of prospectively collected data was undertaken on patients undergoing surgery between 1993 and 2005 for metastatic sarcoma to the brain at The University of Texas, M.D. Anderson Cancer Center.
During the study period, 62 patients underwent 84 operations for metastatic sarcoma to the brain. The median postoperative overall and progression-free survival rates were 7.5 and 4.7 months, respectively. Fifty-nine (95%) of 62 patients had a gross-total resection. The 30-day mortality rate was 4.2%. The Karnofsky Performance Scale scores at discharge from the hospital and 3 months postoperatively were the same or improved in 50 (85%) of 59 and 26 (51%) of 51, respectively. Overall postcraniotomy survival was 62% at 6 months, 39% at 1 year, 21% at 2 years, and 8% at 5 years. In multivariate and univariate analysis, control of systemic disease, and sarcomas originating from bone, cartilage, or soft tissue were predictors of survival. Patients with control of systemic disease had survival advantage when compared with those who did not. In patients with alveolar soft-part sarcoma, there was a significantly increased survival advantage compared with all other histological subgroups.
The authors' results suggest that in selected patients, resection of metastatic sarcoma to the brain is associated with a relatively low risk of operative death and results in improvement in neurological function. Patients with systemic control of their primary disease and certain histological subtypes (specifically alveolar soft-part sarcoma) have improved overall and progression-free survival.
Ganesh Rao, Darrel S. Brodke, Matthew Rondina, and Andrew T. Dailey
Object. To validate computerized tomography (CT) scanning as a tool to assess the accuracy of thoracic pedicle screw placement, the authors compared its accuracy with that of direct visualization in instrumented cadaveric spine specimens.
Methods. A grading scale was devised to score the placement of the pedicle screw. The grades ranged from 0 to 3 depending on the extent to which the pedicle had been violated. One hundred fifty-five pedicles were fitted with instrumentation in eight cadaveric spines. A single observer graded the appearance of the screw based on CT scans (3-mm axial sections with 1-mm overlap) and direct visualization of the specimen. The authors arrived at a Kappa value of 0.51, which suggested only moderate agreement between the two measurement techniques. Whereas CT had a positive predictive value of 95%, it had a negative predictive value of 62%.
Conclusions. The authors thus conclude that although CT scanning is the most valid tool to assess the accuracy of thoracic pedicle screw placement, it tends to overestimate the number of misplaced screws.
Report of two cases and review of the literature
Ganesh Rao, Richard C. E. Anderson, Neil A. Feldstein, and Douglas L. Brockmeyer
✓Arachnoid cysts are intracranial, space-occupying lesions that typically remain stable in size on serial imaging. The authors describe two cases of rapidly enlarging arachnoid cysts, including one located in the anterior fossa.
In the first case a 7-month-old boy presented with increasing head circumference and a rapidly enlarging arachnoid cyst in the left middle fossa, which had been documented by serial imaging over the preceding 6 months. In the second case a 4-year-old girl presented with an arachnoid cyst compressing the right frontal lobe. The cyst had not been present on imaging studies performed during the perinatal period. In both cases, a craniotomy for open fenestration of the cyst was performed with successful resolution of the mass effect.
Rare cases of expansion of arachnoid cysts have been reported in the literature. In this article the authors report the dramatic enlargement of two arachnoid cysts, including the first description of enlargement of an arachnoid cyst located in the anterior fossa.
Case report and classification scheme
Paul Klimo Jr., Ganesh Rao, Richard H. Schmidt, and Meic H. Schmidt
Nerve sheath tumors that involve the sacrum are rare. Delayed presentation is common because of their slow-growing nature, the permissive surrounding anatomical environment, and nonspecific symptoms. Consequently, these tumors are usually of considerable size at the time of diagnosis.
The authors discuss a case of a sacral nerve sheath tumor. They also propose a classification scheme for these tumors based on their location with respect to the sacrum into three types (Types I–III). Type I tumors are confined to the sacrum; Type II originate within the sacrum but then locally metastasize through the anterior and posterior sacral walls into the presacral and subcutaneous spaces, respectively; and Type III are located primarily in the presacral/retroperitoneal area. The overwhelming majority of sacral nerve sheath tumors are schwannomas. Neurofibromas and malignant nerve sheath tumors are exceedingly rare. Regardless of their histological features, the goal of treatment is complete excision. Adjuvant radiotherapy may be used in patients in whom resection was subtotal. Approaches to the sacrum can generally be classified as anterior or posterior. Type I tumors may be resected via a posterior approach alone, Type III may require an anterior approach, and Type II tumors usually require combined anterior–posterior surgery.
Oren N. Gottfried, Ganesh Rao, Richard C. E. Anderson, Gary L. Hedlund, and Douglas L. Brockmeyer
Ganesh Rao, Robert Bohinski, Iman Feiz-Erfan, and Laurence D. Rhines
✓The retroperitoneal surgical approach has gained acceptance as a way to access the ventral aspect of the lumbar spine. Visualization is often limited, however, by the psoas muscle, which lies along the posterolateral aspect of the spine. Improved visualization is often attempted by retracting the muscle from the wound, which generally pulls the muscle laterally from the spine but not posteriorly, which is desirable for a better exposure of the spine, particularly the neural elements. In this paper, the authors describe a simple, atraumatic technique for retraction of the psoas muscle that allows excellent visualization of the spine.