Daniel D. Cavalcanti, Nikolay L. Martirosyan, Ketan Verma, Sam Safavi-Abbasi, Randall W. Porter, Nicholas Theodore, Volker K. H. Sonntag, Curtis A. Dickman and Robert F. Spetzler
Schwannomas occupying the craniocervical junction (CCJ) are rare and usually originate from the jugular foramen, hypoglossal nerves, and C-1 and C-2 nerves. Although they may have different origins, they may share the same symptoms, surgical approaches, and complications. An extension of these lesions along the posterior fossa cisterns, foramina, and spinal canal—usually involving various cranial nerves (CNs) and the vertebral and cerebellar arteries—poses a surgical challenge. The primary goals of both surgical and radiosurgical management of schwannomas in the CCJ are the preservation and restoration of function of the lower CNs, and of hearing and facial nerve function. The origins of schwannomas in the CCJ and their clinical presentation, surgical management, adjuvant stereotactic radiosurgery, and outcomes in 36 patients treated at Barrow Neurological Institute (BNI) are presented.
Between 1989 and 2009, 36 patients (mean age 43.6 years, range 17–68 years) with craniocervical schwannomas underwent surgical resection at BNI. The records were reviewed retrospectively regarding clinical presentation, radiographic assessment, surgical approaches, adjuvant therapies, and follow-up outcomes.
Headache or neck pain was present in 72.2% of patients. Cranial nerve impairments, mainly involving the vagus nerve, were present in 14 patients (38.9%). Motor deficits were found in 27.8% of the patients. Sixteen tumors were intra- and extradural, 15 were intradural, and 5 were extradural. Gross-total resection was achieved in 25 patients (69.4%). Adjunctive radiosurgery was used in the management of residual tumor in 8 patients; tumor control was ultimately obtained in all cases.
Surgical removal, which is the treatment of choice, is curative when schwannomas in the CCJ are excised completely. The far-lateral approach and its variations are our preferred approaches for managing these lesions. Most common complications involve deficits of the lower CNs, and their early recognition and rehabilitation are needed. Stereotactic radiosurgery, an important tool for the management of these tumors as adjuvant therapy, can help decrease morbidity rates.
Francisco A. Ponce, Brendan D. Killory, Scott D. Wait, Nicholas Theodore and Curtis A. Dickman
Thoracoscopy may be used in place of thoracotomy to resect intrathoracic neoplasms such as paraspinal neurogenic tumors. Although these tumors are rare, they account for the majority of tumors arising in the posterior mediastinum.
A database was maintained of all patients undergoing thoracoscopic surgery for tumors. The authors analyzed the presenting symptoms, pathological diagnoses, and outcomes of 26 patients (7 males and 19 females, mean age 37.2 years) who were treated for intrathoracic tumors via thoracoscopy between January 1995 and May 2009. Fourteen patients were diagnosed incidentally (54%). Five patients (19%) presented with dyspnea or shortness of breath, 4 (15%) with pain, 1 (4%) with pneumonia, 1 (4%) with hoarseness, and 1 (4%) with Horner syndrome.
Pathology demonstrated schwannomas in 20 patients (77%). Other diagnoses included ganglioneurofibroma, paraganglioma, epithelioid angiosarcoma, benign hemangioma, benign granular cell tumor, and infectious granuloma. One patient required conversion to open thoracotomy due to pleural scarring to the tumor. One underwent initial laminectomy due to intraspinal extension of the tumor. Gross-total resection was obtained in 25 cases (96%). The remaining patient underwent biopsy followed by radiation therapy. The mean surgical time was 2.5 hours, and the mean blood loss was 243 ml. The mean duration of chest tube insertion was 1.3 days, and the mean length of hospital stay was 3.0 days. Cases that were treated in the second half of the cohort were more often diagnosed incidentally, performed in less time, and had less blood loss than those in the first half of the cohort. There was 1 case of permanent treatment-related morbidity (mild Horner syndrome). All previously employed patients were able to return to work (mean clinical follow-up 43 months). There were no recurrences (mean imaging follow-up 54 months).
Endoscopic transthoracic approaches can reduce approach-related soft-tissue morbidity and facilitate recovery by preserving the normal tissues of the chest wall, by avoiding rib retraction and muscle transection, and by reducing postoperative pain. This less invasive approach thus shortens hospital stay and recovery time.
Eric M. Horn, Iman Feiz-Erfan, Gregory P. Lekovic, Curtis A. Dickman, Volker K. H. Sonntag and Nicholas Theodore
Although rare, traumatic occipitoatlantal dislocation (OAD) injuries are associated with a high mortality rate. The authors evaluated the imaging and clinical factors that determined treatment and were predictive of outcomes, respectively, in survivors of this injury.
The medical records and imaging studies obtained in 33 patients with OAD were reviewed retrospectively. Clinical factors that predicted outcomes, especially neurological injury at presentation and imaging findings, were evaluated.
The most sensitive method for the diagnosis of OAD was the measurement of basion axial–basion dens interval on computed tomography (CT) scanning. Five patients with severe traumatic brain injuries (TBIs) were not treated and subsequently died. Of the 28 patients in whom treatment was performed, 23 underwent fusion and five were fitted with an external orthosis. Abnormal findings of the occipitoatlantal ligaments on magnetic resonance (MR) imaging, associated with no or questionable abnormalities on CT scanning, provided the rationale for nonoperative treatment. Of the 28 patients treated for their injuries, perioperative death occurred in five, three of whom had presented with severe neurological injuries. The mortality rate was highest in patients with a TBI at presentation. The mortality rate was lower in patients presenting with a spinal cord injury, but in this group there was a higher rate of persistent neurological deficits.
The spines in patients with CT-documented OAD are most likely unstable and need surgical fixation. In patients for whom CT findings are normal and MR imaging findings suggest marginal abnormalities, nonoperative treatment should be considered. The best predictors of outcome were severe brain or upper cervical injuries at initial presentation.
Eric M. Horn, Nicholas Theodore, Iman Feiz-Erfan, Gregory P. Lekovic, Curtis A. Dickman and Volker K. H. Sonntag
The risk factors of halo fixation in elderly patients have never been analyzed. The authors therefore retrospectively reviewed data obtained in the treatment of such cases.
A discharge database was searched for patients 70 years of age or older who had undergone placement of a halo device. In a search of cases managed between April 1999 and February 2005, data pertaining to 53 patients (mean age 79.9 years [range 70–97 years]) met these criteria. Forty-one patients were treated for traumatic injuries. Ten patients had deficits ranging from radiculopathy to quadriparesis, and 43 had no neurological deficit. Adequate follow-up material was available in 42 patients (mean treatment duration 91 days). Halo immobilization was the only treatment in 21 patients, and adjunctive surgical fixation was undertaken in the other 21 patients. There were 31 complications in 22 patients: respiratory distress in four patients, dysphagia in six, and pin-related complications in 10. Eight patients died; in two of these cases, the cause of death was clearly unrelated to the halo brace. The other six patients died of respiratory failure and cardiovascular collapse (perioperative mortality rate 14%). Three patients who died had sustained acute trauma and three had undergone surgical stabilization.
External halo fixation can be used safely to treat cervical instability in elderly patients. The high complication rate in this population may reflect the significant incidence of underlying disease processes.
Geun Sung Song, Nicholas Theodore, Curtis A. Dickman and Volker K. H. Sonntag
✓ Bilateral posterior C1–2 transfacet screw placement with associated posterior bone graft wiring is the accepted treatment for patients with atlantoaxial instability. This technique was modified to treat 19 patients with atlantoaxial instability and unilateral anomalies that prevented placement of a screw across the C1–2 facet. In these cases, a single contralateral transarticular screw was placed in conjunction with interspinous bone graft wiring to avoid neural or vertebral artery injury and to provide C1–2 stability. Postoperatively, all 19 patients were placed in Philadelphia collars (mean immobilization 8 weeks, range 6–12 weeks). Unilateral C1–2 facet screw fixation was needed for the following reasons: a high-riding transverse foramen of the C-2 vertebra present in 13 patients (left side in eight, right side in five), poor screw purchase in two (left side in both), screw malposition in one (left side), severe degenerative arthritis in one (right side), neurofibroma in one (right side), and fracture of the C-1 lateral mass in one (left side). Six weeks postsurgery, one patient presented with a broken screw and required occipitocervical fusion with a Steinmann pin and wire cable from the occiput to C-3 to achieve solid fusion. Solid fusions were achieved in the other 18 patients (mean follow-up period 31 months, range 14–54 months); there was no delayed screw breakage, wire breakage, or spinal instability. There were no operative or postoperative neurological or vascular complications. The authors' experience demonstrates that unilateral C1–2 facet screw fixation with interspinous bone graft wiring is an excellent alternative in the treatment of atlantoaxial instability when bilateral screw fixation is contraindicated.