✓ This report discusses the authors' technique in performing anterior cervical vertebrectomy and interbody fusion for multilevel cervical disease. The technique is performed with a high-speed drill and bone-bank fibular strut graft. After decompression of the cervical canal, ledges are made in the intact vertebral bodies to create a rectangular bed for safe seating of the bone graft. The bone-bank fibular strut graft is a feasible alternative to autograft. The simplified and safe nature of this procedure reduces postoperative morbidity as well as the length of hospital stay.
Deepak Awasthi and Rand M. Voorhies
Arteriovenous fistula with associated aneurysms coexisting with dural arteriovenous malformation of the anterior inferior falx
Case report and review of the literature
John Ratliff and Rand M. Voorhies
✓ This 24-year-old man presented with an unusual case of a high-flow arteriovenous fistula (AVF). This lesion was similar to giant AVFs in children that have been previously described in the literature. In patients in whom abnormalities of the vein of Galen have been excluded and in whom presentation occurs after 20 years of age, a diagnosis of congenital AVF is quite unusual.
The fistula in this case originated in an enlarged callosomarginal artery and drained into the superior sagittal sinus via a saccular vascular abnormality. Two giant aneurysmal dilations of the fistula were present. In an associated finding, a small falcine dural arteriovenous malformation (AVM) was also present. Arterial supply to the AVM arose from both external carotid arteries and the left vertebral artery, with drainage through an aberrant vein in the region of the inferior sagittal sinus into the vein of Galen.
Craniotomy with exposure and trapping of the AVF was performed, with subsequent radiosurgical (linear accelerator) treatment of the dural AVM. Through this combination of microsurgical trapping of the AVF and radiotherapy of the dural AVM, an excellent clinical outcome was achieved.
Francis W. Gamache Jr. and Rand M. Voorhies
✓ Problems associated with osteophytes of the spine are frequently called to the attention of the neurosurgeon. Diffuse idiopathic skeletal hyperostosis (Forestier's disease) is a common disorder of the spine; a small but important number of these patients present with spondylitic dysphagia. Anterior cervical decompression restores esophageal function. A patient with Forestier's disease is reported, and Forestier's disease is compared and contrasted with other disorders of the spine.
H. Carson McKowen and Rand M. Voorhies
✓ The quadrilateral space syndrome is a recently established entity with seemingly consistent pathological and radiographic features. An example of this syndrome is reported. In this patient, entrapment of the axillary nerve by fibrous bands in the quadrilateral space caused shoulder pain with paresthesias in the upper extremity. Subclavian angiography provided the diagnosis by demonstrating that the posterior humeral circumflex artery, which was normal when the arm was in a neutral position, was occluded when the arm was abducted and externally rotated. Axillary neurolysis through a posterior approach resulted in relief of symptoms.
Rand M. Voorhies and Richard A. R. Fraser
✓ A case of air embolism complicating cerebral angiography is presented. The presence of the embolism was confirmed with high-resolution computerized tomography scans using appropriate window settings.
Rand M. Voorhies and Richard A. R. Fraser
✓ A simple method, utilizing a vertically hinged flap of lumbodorsal fascia, is described for closure of lowlying myelomeningocele defects.
An evaluation of preoperative diagnostic tests
Rand M. Voorhies, Narayan Sundaresan and H. Tzvi Thaler
✓ The role of preoperative diagnostic tests was evaluated in 210 adult patients with single supratentorial lesions demonstrated by computerized tomography. At craniotomy, 59.5% of these patients proved to have primary brain tumors, 36.2% had metastatic tumors, and 4.3% had non-neoplastic lesions. In 23 (11%) of these patients, a single brain metastasis was the first manifestation of a systemic cancer. The primary site of cancer was identified in 14 patients (10 in the lung, three in the kidney, and one in the colon), and in nine patients the primary site could not be established. Using simple conditional probability theory, we established that the probability of a metastatic lesion in patients without a history of previously treated cancer is about 7%, if their chest x-ray film and intravenous pyelogram (IVP) are negative. Extensive preoperative testing to try to establish a primary site is unrewarding if the chest x-ray film and IVP are negative, since these are the only sites likely to be identified in these patients. In patients with a history of previously treated cancer, these tests are justified because they have prognostic value in determining treatment.
Thomas R. Donner, Rand M. Voorhies and David G. Kline
✓ Over a 22-year period, operations were performed on 263 patients for 288 primary benign tumors of major peripheral nerves. The tumors included 85 schwannomas, 197 neurofibromas, and six plexiform neurofibromas. Total removal was achieved in 83 of the 85 schwannomas, and 76 of these patients were available for follow-up evaluation. Motor function either improved or was unchanged in 87% of these patients and 85% of those with pain in the distribution of the involved nerve had either total or partial resolution of their symptoms. Of the neurofibromas, 123 occurred in 121 patients without von Recklinghausen's disease. All tumors within this group were completely excised using a fascicular approach to the tumor. Of the 99 patients available for follow-up evaluation, 90% had either improved or unchanged motor function and 88% had partial or complete resolution of pain syndromes. Fifty-nine patients with von Recklinghausen's disease had 80 tumors removed: 74 fusiform tumors (58 of which were completely removed) and six plexiform tumors. Forty-eight of the 58 patients with gross total removal of fusiform tumors were available for follow-up evaluation, of whom 83% had improved or unchanged motor function and 74% had partial or complete resolution of pain syndromes. All six patients with plexiform tumors had progression of symptoms postoperatively. One brachial plexus schwannoma recurred and was re-excised without subsequent recurrence at the 5-year follow-up evaluation. Several incompletely excised plexiform neurofibromas have recurred with a symptomatic presentation.
Case report and review of the literature
Gregory C. Dowd, Timothy B. Molony and Rand M. Voorhies
✓ Pneumocephalus is commonly seen in clinical neurosurgical practice. Typical causes include trauma, tumor, and infection. Pneumocephalus may also occur iatrogenically at the time of intracranial surgery; it is not pathological and may be seen routinely on postoperative neuroimaging. Pneumocephalus is rarely encountered in the absence of the aforementioned entities. The authors report on an elderly woman in whom spontaneous intraventricular pneumocephalus occurred because of a congenital defect in the left tegmen tympani. Eustachian tube closure and middle ear exclusion were used to obliterate the fistulous connection. This case illustrates both an unusual cause and a unique treatment for spontaneous otogenic pneumocephalus.
Gabriel C. Tender, Richard V. Baratta and Rand M. Voorhies
Object. Lumbar radiculopathy secondary to foraminal entrapment can be treated by unilateral removal of the overlying pars interarticularis. The authors prospectively evaluated the outcome after this procedure.
Methods. Thirty-six consecutive patients underwent unilateral resection of the pars interarticularis between August 1999 and July 2002. In 18 patients acute foraminal disc herniations compressed the nerve root against the superior pedicle; in the other 18 foraminal stenosis was secondary to degenerative changes. All patients, at each visit, completed the following questionnaires: visual analog scale for overall, leg, and back pain; the Prolo Functional Economic Rating scale; and the Pain Rating Index (PRI) of the Short-Form McGill Pain Questionnaire.
At 1 year, leg pain improved in 33 patients (91%). Low-back pain appeared or worsened in eight patients (22%; one in the acute herniation group and seven in the chronic degenerative group). Only one patient required lumbar fusion for pain. The Prolo economic and function scores improved in 21 (58%) and 27 (75%) patients, respectively. The PRI scores improved in 30 cases (83%). No spondylolisthesis was observed at any level at which resection had been performed.
Conclusions. Unilateral removal of the pars interarticularis is effective in relieving lumbar radicular symptoms in patients with intraforaminal entrapment. The incidence of low-back pain in patients with acute foraminal disc herniations does not increase as a result of this procedure. In patients with degenerative foraminal stenosis, unilateral resection of the pars interarticularis may be a better alternative to facetectomy and segmental fusion. This procedure may be a useful tool in spine surgery.