Michael J. Harrison, Blake G. Welling and Jeffrey J. Dubois
✓ This technical note describes a simple percutaneous mechanism for placement of the atrial end of ventriculoatrial shunts. The method is fast, efficient, and involves no neck dissection. No special equipment is required. Placement involves the technique of central line insertion familiar to all surgeons. This new method has been used successfully in one adult and one pediatric patient.
Michael J. Harrison, Susan Morgello and Kalmon D. Post
✓ Cystic epithelial lesions of the sellar and parasellar region are classified on the basis of histology and location into Rathke's cleft cysts, epithelial cysts, epidermoid cysts, dermoid cysts, and craniopharyngiomas. A retrospective review of the clinical presentation, radiological findings, and histology was performed on 19 such lesions, and a survey of the literature pertinent to the classification, clinical presentation, and embryology of these lesions was conducted.
Presentation was nonspecific and not predictive of histology. Imaging studies were generally useful in distinguishing these tumors, with the exception of Rathke's cleft cysts, suprasellar epidermoid cysts, and craniopharyngiomas, which frequently could not be differentiated. On microscopic examination, most lesions fit into distinct categories; however, overlap was common among all and some could not be definitively categorized by histological criteria.
Evidence supportive of an ectodermal ancestry for sellar and parasellar epithelial-lined cystic lesions is presented. Based on the current findings and a review of the literature, it is suggested that these lesions represent a continuum of ectodermally derived cystic epithelial lesions.
Michael J. Harrison, Robin J. Mitnick, Bruce R. Rosenblum and Allen S. Rothman
✓ Leptomyelolipoma (lumbosacral lipoma) is a common form of spinal dysraphism. The deficits produced include sensory, motor, bowel, and bladder dysfunction, and vary in incidence between the pediatric and adult populations. Twenty patients treated surgically at the Mount Sinai Hospital between 1972 and 1988 are reviewed. Fifty percent were 12 years of age or less and 50% were older than 18 years of age. The surgical approach was designed to accomplish untethering of the conus medullaris, debulking of the lipomatous mass compressing the cord, reconstruction of the dural canal, and reapproximation of the paraspinal muscles and lumbosacral fascia to prevent future trauma. Postoperatively, no patient experienced deterioration of neurological function. Of the symptomatic patients, 67% displayed dramatic improvement or became asymptomatic and 33% experienced stabilization of their deficits. The symptoms most resistant to surgical correction were orthopedic foot deformities and bowel dysfunction, whereas bladder dysfunction, motor weakness, and radiculopathies were most amenable to surgical therapy. Early surgical repair is recommended in these cases to forestall irreversible neurological damage.
Randall R. McCafferty, Michael J. Harrison, Laszlo B. Tamas and Mark V. Larkins
✓ A retrospective review was conducted on the records and radiographs of six symptomatic patients and one asymptomatic patient with Forestier's disease. No other series of patients with this disease is found in the neurosurgical literature. Forestier's disease, also known as diffuse idiopathic skeletal hyperostosis (DISH), is an idiopathic rheumatological abnormality in which exuberant ossification occurs along ligaments throughout the body, but most notably the anterior longitudinal ligament of the spine. It affects older men predominantly; all of our patients were men older than 60 years of age. The disease is usually asymptomatic; however, dyspnea, dysphagia, spinal cord compression, and peripheral nerve entrapment have all been documented in association with the disorder. Five of the six symptomatic patients presented with dysphagia due to esophageal compression by calcified anterior longitudinal ligaments, and one patient developed recurrent spinal stenosis when scar tissue from a previous decompressive laminectomy became calcified. All patients responded well to surgery. Two of the four patients who underwent removal of cervical osteophytes required several months following surgery for the dysphagia to resolve. This would support the hypothesis that not all cases of dysphagia in Forestier's disease are due to mechanical compression. Dysphagia may result from inflammatory changes that accompany fibrosis in the wall of the esophagus or from esophageal denervation. Evaluation of dysphagia even in the presence of Forestier's disease must rule out occult malignancy. The authors' experience suggests that dysphagia in the setting of Forestier's disease is an underrecognized entity amenable to surgical intervention.
Philip Tsitsopoulos, Ana Maria B. Malbouisson and Michael J. G. Harrison
✓ A study of technical problems in the performance of microvascular anastomosis has been carried out in the rat. A comparison of two types of suture material suggested that handling characteristics had a significant effect on the time taken to complete the anastomosis, and on the accuracy of apposition of the vessel walls. Technical difficulties encountered intraoperatively proved predictive of subsequent compromise of the lumen, shown angiographically and histologically. The optimum conditions are discussed, and it is argued that postoperative antithrombotic medication is indicated when technical problems are encountered.
Michael J. Harrison, David E. Wolfe, Tai-Shing Lau, Robin J. Mitnick and Ved P. Sachdev
✓ From the records of The Mount Sinai Hospital, seven cases which met established criteria for radiation-induced meningiomas were identified. This represents the largest series of radiogenic meningiomas documented in North America and includes both intracranial and intraspinal tumors. The records and pathological specimens were reviewed and these data analyzed with other cases retrieved from the world literature. This study reveals that radiation-induced meningiomas can be categorized into three groups based on the amount of radiation administered: 1) low dose; 2) moderate dose and miscellaneous; and 3) high dose. The overwhelming majority of cases had received low-dose irradiation (800 rad) to the scalp for tinea capitis and the second largest group resulted from high-dose irradiation for primary brain tumors (> 2000 rad).
The unique features distinguishing radiation-induced meningiomas from other meningiomas are reviewed. Although histologically atypical tumors were common in this series, overt malignancy was not encountered. The preoperative management of these lesions should include angiography to evaluate for large-vessel occlusive vasculopathy, a known association of meningiomas induced by high-dose irradiation. Given the propensity these tumors possess for recurrence, a wide bony and dural margin is recommended at surgical resection.
Ossama Al-Mefty, Cahide Topsakal, Svetlana Pravdenkova, Jeffrey R. Sawyer and Michael J. Harrison
Object. Radiation-induced meningiomas are known to occur after high- and low-dose cranial radiation therapy. The goal of this study was to discern the distinguishing findings and characteristics of radiation-induced meningiomas.
Methods. The records of 16 patients (seven men and nine women) who fulfilled the criteria for radiation-induced meningiomas were retrospectively reviewed. Clinical, histopathological, cytokinetic, and cytogenetic findings as well as the patients' outcome were analyzed.
The mean age of the patients was 38.8 years and the mean tumor latency was 26.5 years. Five patients had multiple meningiomas in the irradiated field. The recurrence rate was 100% after the initial resection; 62% of patients had a second recurrence and 17% had a third recurrence. Thirty-eight percent of patients had atypical or malignant histopathological findings. The presence of progesterone receptors and low proliferation indices in these patients did not correlate with benign tumor behavior. Cytogenetic analysis showed multiple clonal aberrations in all tumors studied. The most frequent aberrations were found on chromosomes 1p, 6q, and 22. Derivative, lost, or additional chromosome 1p was found in 89% of cases and loss or deletion on chromosome 6 was found in 67%.
Conclusions. The age of patients at presentation with meningioma and the latency period of radiation-induced meningiomas are dose related. These tumors are more aggressive and are certain to recur, have a higher histopathological grade, and are associated with complex cytogenetic aberrations particularly involving 1p and 6q.
Linda M. Luxon and Michael J. G. Harrison
✓ An unusual case of a cervical neurilemmoma is presented. A 67-year-old man developed papilledema on two occasions in association with the symptoms and signs of a subarachnoid hemorrhage (SAH). He proved to have an otherwise asymptomatic cervical neurilemmoma. It is suggested that both acute and subclinical bleeding from such tumors may sometimes underlie the development of raised intracranial pressure occasionally encountered. The clinical clue to the spinal origin of the SAH was an acute onset with root pain. This case is discussed with reference to similar cases in the literature.