✓ A simple wire template is placed on the patient's head during computerized tomography scanning, and the results of the scan are later reproduced on the scalp prior to surgery. Measurements of the distance between the wires and the relationship of the mass provide the key to accurate localization of the mass on the scalp surface.
John I. Moseley, Steven L. Giannotta and Justin W. Renaudin
John G. Frazee, Steven L. Giannotta and W. Eugene Stern
✓ A primate model of chronic cerebral vasoconstriction is presented which closely approximates the human experience following subarachnoid hemorrhage. Treatment of the vasoconstriction with intravenous nitroglycerin produces a modest, but statistically significant, increase in the size of the most constricted vessels (11%, p < 0.02) when compared with a control infusion of normal saline. The significance of these experiments is discussed.
An analysis of 45 cases
Michael L. J. Apuzzo, William R. Dobkin, Chi-Shing Zee, James C. Chan, Steven L. Giannotta and Martin H. Weiss
✓ Infestations of the human brain with the larval stage of Taenia solium, once an infrequent diagnosis in the United States, is now a more frequently encountered clinical entity especially in population centers with high immigrant flux. During a recent 5-year period 45 cases of intraventricular cysticercosis have been evaluated and treated. Modes of involvement included isolated cyst formation, ependymitis, or combinations of both. Evidence of associated parenchymatous involvement was present in 20% of cases. Sites of infestation included the lateral ventricle (five cases), third ventricle (12 cases), Sylvian aqueduct (four cases), and fourth ventricle (24 cases). Mean post-therapy follow-up periods for this series exceed 36 months. This experience indicates that direct excision is the treatment of choice for ventricular cystic lesions, but that management, operative planning, and expectations should be influenced by considerations of: 1) the potential for acute clinical deterioration (38%); 2) the potential for cyst migration; 3) attendant ependymitis, defined by computerized tomography or verified at surgery; 4) the potential for increase in cyst volume with local mass effect; 5) selection and institution of corridors of surgical access that establish alternative routes of cerebrospinal fluid flow; and 6) the possibility of cyst excision by a stereotaxic endoscopic procedure.
Steven L. Giannotta and Dennis R. Maceri
✓ A retrolabyrinthine transsigmoid approach was employed successfully in three patients with vertebrobasilar aneurysms. The major benefits of this technique include a relatively shallow depth of exposure, lack of brain stem retraction, and simplicity as compared to traditional and some recently proposed methods. All three patients have returned to their previous activities.
Howard Tung, Steven L. Giannotta, Parakrama T. Chandrasoma and Chi-Shing Zee
✓ Thirteen patients with recurrent hemorrhages from angiographically occult vascular malformations are presented. Recurrent hemorrhages were indicated by the exacerbation of neurological deficits, the appearance of a new neurological deficit, or the onset of acute severe headache confirmed by evidence of recent hemorrhage on either computerized tomography or magnetic resonance imaging. Persistent neurological deficits correlated with an increased number of recurrent hemorrhages and their location. The median time from initial hemorrhage to the first recurrent hemorrhage was 12 months and the second rebleed generally occurred much earlier, with a median time of 2 months after the first. Eight patients underwent surgery with total excision and favorable results. One patient with a large pontine lesion underwent partial excision and has had a progressing neurological deficit from recurrent hemorrhages. Histopathological review confirmed the excised lesions to be cavernous angiomas. The authors conclude that angiographically occult vascular malformations are not the benign entity they were previously thought to be, and that they are prone to cause recurrent hemorrhages and persistent neurological deficits. Surgery can be effective and relatively safe in removing these lesions even in eloquent areas of the brain, but the necessity of occasional incomplete removal must be recognized in order to avoid creating an unacceptable neurological outcome.
Michael L. Levy and Steven L. Giannotta
✓ The effect of hypervolemic preload enhancement on cardiac performance was systematically analyzed in nine patients following aneurysmal subarachnoid hemorrhage. The patients ranged in age from 34 to 63 years, and none had a history of cardiac disease. Each patient underwent placement of a flow-directed balloon-tipped catheter and the following measurements were taken during hypervolemic therapy: pulmonary artery wedge pressure (PAWP), central venous pressure (CVP), cardiac index (CI), stroke volume index (SVI), and left ventricular stroke work index (LVSWI). After baseline measurements were recorded, hetastarch or plasmanate was infused intravenously at 300 cc/hr. Thermal output determination and pressures were measured every 15 minutes. The PAWP did not correlate in a statistically significant fashion with the CVP in the ranges recorded; however, a statistically significant correlation did exist between PAWP increases and increases in CI, SVI, and LVSWI (p < 0.01). There was no statistical correlation between PAWP increases above 14 mm Hg and improvement in cardiac performance as evidenced by CI, SVI, and LVSWI measurements. It is concluded that CVP is an unreliable index of cardiac performance during hypervolemic therapy and that, in previously healthy individuals, a PAWP of 14 mm Hg is associated with maximum cardiac performance.
Adrian L. Rabinowicz, David L. Ginsburg, Christopher M. DeGiorgio, Peggy S. Gott and Steven L. Giannotta
✓ Twenty-one patients operated on for unruptured intracranial aneurysms were studied retrospectively in order to identify the incidence of postoperative seizures, factors predictive of seizures, and the response to discontinuation of antiepileptic drugs. The overall risk of postoperative seizures in initially seizure-free patients was 15.7%. Although seizures were not uncommon, antiepileptic drugs were successfully tapered in most of the patients before 12 months.
Michael L. Levy, Craig H. Rabb, Vladimir Zelman and Steven L. Giannotta
✓ The use of the beta-agonist dobutamine in combination with hypervolemic preload enhancement of cardiac performance was analyzed in 23 patients who failed to respond to traditional preload enhancement following aneurysmal subarachnoid hemorrhage. The patients ranged in age from 13 to 82 years, and three had a history of cardiac disease. Each patient underwent placement of a flow-directed balloon-tipped catheter and the following measurements were obtained during hyperdynamic therapy: pulmonary artery wedge pressure, central venous pressure, cardiac index, stroke volume index, total peripheral resistance, and left ventricular stroke work index (LVSWI). Mean baseline cardiac function was found to be within normal limits (LVSWI = 47.6 ± 4.2 gm/min/sq m and cardiac index = 3.30 ± 0.22 liter/min/sq m). After baseline measurements were recorded, 5% albumin was infused at 300 cc/hr and dobutamine was initiated at a rate of 5 to 10 µg/kg/hr. This hyperdynamic therapy with dobutamine in the presence of volume loading resulted in a 52% increase in cardiac index, a 15% increase in LVSWI, and a 21% decrease in total peripheral resistance. The clinical reversal of ischemic symptoms due to subarachnoid hemorrhage was evident in 18 (78%) of the 23 patients.