Duke Samson

Factors related to hydrocephalus after aneurysmal subarachnoid hemorrhage.

OBJECTIVEThe purpose of this study was to identify factors predictive of shunt-dependent hydrocephalus among patients with aneurysmal subarachnoid hemorrhage. The data can be used to predict which patients in this group have a high probability of requiring permanent cerebrospinal fluid diversion. METHODSSeven hundred eighteen patients with aneurysmal subarachnoid hemorrhage who were treated between 1990 and 1999 were retrospectively studied, to identify factors contributing to shunt-dependent hydrocephalus. With these data, a stepwise logistic regression procedure was used to determine the effect of each variable on the development of hydrocephalus and to create a scoring system. RESULTSOverall, 152 of the 718 patients (21.2%) underwent shunting procedures for treatment of hydrocephalus. Four hundred seventy-nine of the patients (66.7%) were female. Of the factors investigated, the following were associated with shunt-dependent hydrocephalus, as determined with a variety of statistical methods: 1) increasing age (P < 0.001), 2) female sex (P = 0.015), 3) poor admission Hunt and Hess grade (P < 0.001), 4) thick subarachnoid hemorrhage on admission computed tomographic scans (P < 0.001), 5) intraventricular hemorrhage (P < 0.001), 6) radiological hydrocephalus at the time of admission (P < 0.001), 7) distal posterior circulation location of the ruptured aneurysm (P = 0.046), 8) clinical vasospasm (P < 0.001), and 9) endovascular treatment (P = 0.013). The presence of intracerebral hematomas, giant aneurysms, or multiple aneurysms did not influence the development of shunt-dependent hydrocephalus. CONCLUSIONThe results of this study can help identify patients with a high risk of developing shunt-dependent hydrocephalus. This may help neurosurgeons expedite treatment, may decrease the cost and length of hospital stays, and may result in improved outcomes.

A current review of brain abscess

Abstract A review of the current status of the incidence, pathogenesis, causative organism, diagnostic methods, and therapy of brain abscess has been done. We leave contrasted our results with those published with regard to mortality and morbidity. From our series, it appears that the greatest danger to the patient with a brain abscess is not infection, but the mass effect of the abscess. Patients with suspected brain abscess should undergo brain scan and cerebral arteriography as the diagnostic and localizing test of choice. Lumbar puncture is hazardous, and yields only suggestive information. A combination of wide spectrum antibiotic therapy and surgical excision of the abscess yields superior results over other methods of treatment.

A Clinical Study of the Parameters and Effects of Temporary Arterial Occlusion in the Management of Intracranial Aneurysms

Temporary occlusion of intracranial arteries has emerged as a valuable technical adjunct in the management of intracranial aneurysms. The current study considered 121 patients (from a group of 234 consecutive aneurysm patients treated during a 2-yr period) who underwent elective temporary arterial occlusion. Twenty-one patients were excluded from further study because of an intraoperative rupture of an aneurysm, the elective sacrifice of afferent or efferent vessels, or the performance of an extracranial-intracranial arterial bypass graft; the remaining 100 patients underwent elective temporary occlusion under a standard neuroanesthetic regimen, including etomidate-induced burst suppression, normotension, normovolemia, and normothermia. In the postoperative period, radiographic evidence of ischemic brain injury in the distribution of the arteries occluded was selected as the end point for the failure of occlusion tolerance. The parameters evaluated with respect to this end point included the duration and nature of the temporary arterial occlusion, the number of the occlusive episodes, the specific vascular territory occluded, patient age, neurological status, presence of subarachnoid hemorrhage, vasospasm, and aneurysm size. Several parameters were found to be related to the postoperative development of ischemic injury. Patients more than 61 years of age and those in poor neurological condition (Hunt and Hess Grades III to IV) did not tolerate temporary occlusion as well as patients who were younger and in better condition. Patients occluded for less than 14 minutes routinely tolerated the iatrogenic ischemia; the 95% confidence level for the toleration of occlusion without the development of infarction occurred at 19 minutes. All patients occluded for more than 31 minutes had both clinical and radiographic evidence of cerebral infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracranial Arteriovenous Malformations Associated with Aneurysms

The presence of intracranial aneurysm in association with arteriovenous malformation has been well documented. Aneurysms have been described in typical proximal sites along the feeding system to the arteriovenous malformation, in abnormal distal locations along feeding vessels, and in sites remote and apparently hemodynamically unrelated to the arteriovenous malformation. Little attention has been focused on the most appropriate medical and surgical care of patients harboring these lesions. Since 1977, 22 patients with this combination of lesions have been evaluated at our institution. Nine patients (41%) presented after intracranial hemorrhage. The remaining 13 patients were investigated because of seizures in 5 patients (23%), headaches in 4 patients (18%), and progressive ischemia in 4 patients (18%). Among the patients suffering intracranial hemorrhage, 78% had bled from an aneurysm, with 22% having hemorrhaged from their arteriovenous malformation. All 7 of the patients who suffered aneurysmal hemorrhage bled from atypical distal aneurysms on major feeding vessels. Our experience and that of others has led us to believe that the safest approach to patients with this combination of lesions is to treat the aneurysm before microsurgical resection of the associated arteriovenous malformation. Hemodynamic changes associated with the abrupt elimination of an arteriovenous malformation may place associated aneurysms at immediate risk.

Intraoperative aneurysmal rupture: Incidence, outcome, and suggestions for surgical management

Intraoperative rupture of an intracranial arterial aneurysm can dramatically interrupt a deliberate microsurgical procedure and jeopardize the patients chances for a favorable outcome. Intraoperative rupture occurred in 58 of 307 (19%) consecutive aneurysm procedures done at The University of Texas Health Science Center. Rupture occurred during three specific periods: early or predissection in 7%, dissection in 48%, and clip application in 45%. Outcome after rupture during the predissection interval was poor, with only 1 of 4 patients surviving. Aneurysmal rupture during dissection could be attributed to blunt dissection techniques in 75% of the cases and to sharp subarachnoid dissection in 25%. The outcome was favorable in only 50% of the patients sustaining blunt dissection errors, whereas all patients sustaining intraoperative rupture during sharp dissection recovered well. Rupture during clip application was attributed to incomplete dissection in 65%, poor clip application in 31%, and a mechanical clip failure in 1 case. Eighty-eight per cent of the patients who underwent uneventful operative procedures had favorable outcomes, whereas only 62% of the patients suffering intraoperative rupture recovered well. The use of sharp microsurgical techniques with a systematic contingency plan for dealing with sudden hemorrhage and the judicious use of temporary clips should minimize the adverse effect of intraoperative rupture on overall management morbidity and mortality.

Cerebrovascular hemodynamics in arteriovenous malformation complicated by normal perfusion pressure breakthrough

Catastrophic hyperemic states are known complications after the treatment of certain types of intracranial arteriovenous malformations (AVMs). A case is presented in which a large AVM was preoperatively embolized and later resected. There was clear intra- and postoperative evidence of edema and hemorrhage, which resulted in a fatal outcome. Regional cerebral blood flow (rCBF) data from this patient obtained with single photon emission computed tomography (SPECT) both before and after embolization were compared with data from four patients with similar size supratentorial AVMs treated and studied in a similar protocol who did not develop perfusion breakthrough. Pretreatment hemispheric rCBF was significantly reduced in this patients ipsilateral hemisphere (50 ml/100 g/min) compared to the control group mean (83 +/- 9.5 ml/100 g/min). A similar relative depression was found in the contralateral hemisphere. After therapeutic embolization, the ipsilateral rCBF increased by 33 ml/100 g/min and the contralateral hemispheric rCBF increased by 30 ml/100 g/min; this embolization-induced increase in rCBF was significantly higher than in the control group. Acetazolamide, known to increase rCBF in normal tissue by 35 +/- 3%, resulted in a 56% augmentation of ipsilateral hemispheric flow before embolization in the reported patient vs. a 22 +/- 10% increase for the control group. Postembolization, this hyperresponsiveness to acetazolamide remained unchanged. It is possible that these hemodynamic derangements may indicate a dissociation between the vasoconstrictive and vasodilatory reactivity in chronically hypoperfused territories adjacent to AVMs such that pharmacological or metabolic stimuli may induce further vasodilation, but sudden redistribution of large volumes of flow will not promote protective vasoconstriction.

Evolution of the management of tentorial dural arteriovenous malformations

OBJECTIVETentorial dural arteriovenous malformations (DAVMs) are uncommon lesions associated with an aggressive natural history. Controversy exists regarding their optimal treatment. We present a single-institution series of tentorial DAVMs treated during a 12-year period, address the current controversies, and present the rationale for our current therapeutic strategy. METHODSTwenty-two patients with tentorial DAVMs were treated between 1988 and 2000. Treatment consisted of transarterial or transvenous embolization, surgical resection, disconnection of venous drainage, or a combination of these therapies. The clinical presentations, radiological features, treatment strategies, and results were studied. RESULTSEighteen patients (82%) presented with intracranial hemorrhage or progressive neurological deficits. Retrograde leptomeningeal venous drainage was documented in 22 cases (100%), classifying the lesions as Borden Type III. Angiographic follow-up monitoring was performed for 0 to 120 months and clinical follow-up monitoring for 1 to 120 months. Posttreatment angiography demonstrated obliteration in 22 cases (100%). Two patients experienced neurological decline after endovascular treatment and died. All of the 20 surviving patients exhibited clinical improvement; there were no episodes of rehemorrhage or new neurological deficits. Outcomes were excellent in 17 cases (77%), good in 2 cases (9%), and fair in 1 case (5%), and there were 2 deaths (9%). CONCLUSIONTentorial DAVMs are aggressive lesions that require prompt total angiographic obliteration. Disconnection of the venous drainage from the fistula may be accomplished with transarterial embolization to the venous side, transvenous embolization, or surgical disconnection of the fistula. We think that extensive nidal resections carry more risk and are unnecessary. We do not think there is a role for stereotactic radiosurgery in the treatment of these lesions.

Current results of the surgical management of aneurysms of the basilar apex.

OBJECTIVE To provide current information regarding the expected clinical outcomes and sources of morbidity and mortality in the modern surgical management of basilar apex aneurysms. METHOD A retrospective review was conducted of 303 cases of such aneurysms that were treated surgically during 18 years at one institution. Postoperative angiography was performed in 81% of the cases. Clinical grading using the Glasgow Outcome Scale was conducted at the time of hospital discharge and for 91% of the surviving patients at 6 months after surgery. The preoperative parameters that were linked statistically to poor clinical outcome were identified through the use of single and multivariate analyses. RESULTS More than 80% of the patients were operated on using some modification of the trans-sylvian exposure, and temporary arterial occlusion was used routinely. Good outcomes (Glasgow Outcome Scale scores of 4 or 5) were achieved in 76% of the patients at the time of discharge and in 81% of the patients at 6 months after surgery. There was no incidence of postoperative subarachnoid hemorrhage. Residual aneurysm was revealed by postoperative angiography in 6% of the cases. Factors found to be statistically linked to poor outcome included poor admission grade (Hunt and Hess Grades IV and V), patient age older than 65 years, computed tomographic demonstration of thick basal cistern clot, aneurysm size greater than 20 mm, and symptoms attributable to brain stem compression. CONCLUSION Direct microsurgical repair of basilar apex aneurysms should result in good clinical outcomes in 80 to 85% of cases, with reliable prevention of subarachnoid bleeding and routine elimination/reduction of symptoms secondary to mass effect. Those patients who are at high risk for poor outcomes can be identified by the presence of certain clinical, radiographic, and demographic features before undergoing surgery and can be considered for alternative or adjunctive modes of therapy if long-term efficacy of such treatment is demonstrated.

Posteroinferior cerebellar artery aneurysms: Surgical results for 38 patients

OBJECTIVE Posteroinferior cerebellar artery aneurysms have an incidence of approximately 0.49%. Reports in the literature are sparse concerning outcomes in this patient population. We report our results for 38 consecutive patients who were treated during the last 6.5 years. METHODS All patients (n = 38) with posteroinferior cerebellar artery aneurysms that were surgically treated at Zale-Lipshy University Hospital between January 1990 and May 1997 were retrospectively reviewed. Data were collected and analyzed relating to demographics, condition at presentation, lesion characteristics, associated medical problems, postsurgical complications, and outcome. RESULTS Sixty-six percent of the patients (n = 25) experienced neurological sequelae, which included symptomatic vasospasm, hydrocephalus, dysarthria, paresis, diplopia, ataxia, and facial paralysis. Many, however, showed significant improvement during their hospitalization and during the course of the ensuing year. Seventy-four percent of the patients had a Glasgow Outcome Scale score of 1 or 2 at the time of discharge, 91% at 6 months after surgery, and 89% at 1 year after surgery. CONCLUSION This review summarizes the presentations and outcomes of 38 consecutive surgical cases during a 6.5-year period and concludes that posteroinferior cerebellar artery aneurysms are not benign entities. The study does, however, also demonstrate that patients have significant recuperative potential after the treatment of these lesions.

Microsurgical evaluation of the pterional approach to aneurysms of the distal basilar circulation.

The microsurgical correlates the pterional approach to the distal basilar circulation were evaluated in 20 cases of posterior circulation aneurysms, 50 human cadaver dissections, and a variety of other intracranial surgical lesions. The pterional approach permitted successful clipping of the aneurysm in 13 of 15 basilar bifurcation aneurysms, 1 of 2 basilar-posterior cerebral aneurysms, and 2 of 3 basilar-superior cerebellar aneurysms. In each of the failed attempts via the pterional approach, the subtemporal route ultimately resulted in proper clip application. The interposition of the posterior clinoid process was the impediment to successful clipping in three of the four cases that could not be managed via the pterional approach. All 3 of these patients had a basilar bifurcation that was below the level of the posterior clinoid on angiography, whereas none of the remaining 17 aneurysm patients demonstrated a low-lying bifurcation. Posterior displacement of the basilar artery away from the posterior clinoid exceeded 1 cm in only 13% of our cases and was not an impediment to successful clipping of the aneurysm via the pterional route. We conclude that, when the anatomical situation is appropriate, the pterional approach offers the advantages of less brain retraction and better visualization of the parent arteries and important perforating branches when compared to the subtemporal approach.