Complications of preoperative embolization of cerebral arteriovenous malformations.

OBJECT: Preoperative embolization is viewed by the authors as a useful adjunct in the surgical management of cerebral arteriovenous malformations (AVMs). This study was performed to determine the rate of significant complication in patients undergoing this procedure. METHODS: Demographic, anatomical, and procedure data were collected prospectively. The treating physician reported complications. In addition, a review of medical records including procedure reports, operative reports, and discharge summaries was performed. Univariate statistical analysis was performed to determine if any of the variables was predictive of a poor outcome of embolization (death or permanent neurological deficit). Endovascular procedures for embolization were performed 339 times in 201 patients during an 11-year period. Female patients comprised 53.7% of the study group and 85.6% of the AVMs were supratentorial. Embolization was performed using polyvinyl alcohol particles, N-butyl cyanoacrylate, detachable coils, and/or the liquid polymer Onyx. Analyzed by procedure, a poor result of embolization occurred in 7.7%. Analyzed by patient, 11% died or had a permanent neurological deficit as a result of the embolization. None of the demographic, anatomical, or procedure variables identified were predictive of a poor outcome. CONCLUSIONS: Preoperative embolization may gradually reduce flow to an AVM, reduce intraoperative blood loss, and reduce operative time. The risks of this procedure, however, are not insignificant and must be considered in planning treatment for patients with AVMs.

Outcome after subarachnoid hemorrhage from a very small aneurysm: a case-control series.

OBJECT: A case-control analysis of patients with SAH was performed to compare risk factors and outcomes at 6 months posthemorrhage in patients with a very small aneurysm compared with those with a larger aneurysm. METHODS: All patients with SAH who were treated between January 1998 and December 1999 were studied. A very small aneurysm was defined as "equal to or less than 5 mm in diameter." Clinical data and treatment summaries were maintained in an electronic database. The Glasgow Outcome Scale (GOS) score was determined by an independent registrar. One hundred twenty-seven patients were treated. A very small aneurysm was the cause of SAH in 42 patients (33%), whereas 85 (67%) had aneurysms larger than 5 mm (mean diameter 11 mm). There were no differences in demographic variables or medical comorbidities between the two groups. Thick SAH (Fisher Grade 3 or 4) was more common in patients with a very small aneurysm than in those with a larger aneurysm (p = 0.028). One hundred eight patients underwent microsurgery (85%), 15 underwent coil embolization (12%), and four (3%) required both procedures. Vasospasm occurred in nine patients (21%) with very small aneurysms compared with 14 (16%) with larger aneurysms (p = 0.62). Shunt-dependent hydrocephalus occurred in nine patients (21%) with very small aneurysms and in 19 (22%) with larger aneurysms (p = 1). The mean GOS score for both groups was 4 (moderately disabled) at 6 months. CONCLUSIONS: Small aneurysms produce thick SAH more often than larger aneurysms. There is no difference in outcome after SAH between patients with a very small aneurysm and those with a larger aneurysm.

Treatment and outcome in 30 patients with posterior cerebral artery aneurysms.

OBJECT: The records of 30 patients with posterior cerebral artery (PCA) aneurysms treated during a 12-year period were reviewed to determine outcome and the risk of visual field deficit associated with PCA sacrifice. METHODS: Clinical data and treatment summaries for all patients were maintained in an electronic database. The Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores were determined by an independent registrar. Visual field changes were determined by review of medical records. Twenty-eight patients were treated with open surgery, one of them after an attempt at detachable coil embolization failed. Two patients underwent successful endovascular PCA sacrifice. The mean GOS and mRS scores in 18 patients with unruptured aneurysms were 4 and 2, respectively, at discharge. Subarachnoid hemorrhage (SAH) from other aneurysms and neurological deficits caused by the PCA lesion or underlying disease contributed to poor outcomes in this group. The mean GOS and mRS scores in 12 patients with ruptured aneurysms were 4 and 4, respectively, at discharge. One patient died of severe vasospasm. Neurological deficits secondary to SAH and, in one patient, treatment of a concomitant arteriovenous malformation contributed to poor outcomes in the patients with ruptured aneurysms. Seven patients with normal visual function preoperatively underwent PCA occlusion. One patient (14%) developed a new visual field deficit. CONCLUSIONS: Optimal treatment of PCA aneurysms is performed via one of several surgical approaches or by endovascular therapy. The approach is determined, in part, by the anatomical location and size of the aneurysm and the presence of underlying disease and neurological deficits.

Factors related to hydrocephalus after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: The 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. METHODS: Seven 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. RESULTS: Overall, 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. CONCLUSION: The 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.