Faculty Bibliography

BACKGROUND:Cerebral arteriovenous malformations (AVMs) with low Spetzler-Martin grades (I and II) are associated with good neurological outcomes after microsurgical resection; however, the use of preoperative embolization for these lesions is controversial. OBJECTIVE:To compare the neurological outcomes of preoperative embolization with no embolization in patients with low-grade AVMs. METHODS:Patients with a Spetzler-Martin grade I or II AVM who underwent microsurgical resection during January 1, 1997, through December 31, 2019, were analyzed. Patients undergoing preoperative embolization were compared with patients not undergoing embolization. A propensity score was constructed from baseline characteristics and used to match intervention (embolization) and control (nonembolization) groups in a 1:1 ratio. The primary outcome was poor neurological status on last follow-up examination, defined as a modified Rankin Scale score >2 and a modified Rankin Scale score worse at follow-up than at the preoperative examination. RESULTS:Of the 603 patients analyzed, 310 (51.4%) underwent preoperative embolization and 293 (48.6%) did not. Patients in the embolization cohort compared with those in the nonembolization cohort had a higher percentage of Spetzler-Martin grade II AVMs (71.6% vs 52.6%, P < .001) and a lower percentage of hemorrhage (41% vs 55%, P = .001). After propensity score matching, no differences were found between paired cohorts (each N = 203) for baseline characteristics with a significant reduction in absolute standardized mean differences. No significant differences were found in primary outcomes between treatment groups in the matched or unmatched cohorts. CONCLUSION:Preoperative embolization of low-grade Spetzler-Martin AVMs is not associated with improved neurological outcomes after microsurgical resection.

OBJECTIVE:The Barrow Ruptured Aneurysm Trial (BRAT) was a single-center trial that compared endovascular coiling to microsurgical clipping in patients treated for aneurysmal subarachnoid hemorrhage (aSAH). However, because patients in the BRAT were treated more than 15 years ago, and because there have been advances since then-particularly in endovascular techniques-the relevance of the BRAT today remains controversial. Some hypothesize that these technical advances may reduce retreatment rates for endovascular intervention. In this study, the authors analyzed data for the post-BRAT (PBRAT) era to compare microsurgical clipping with endovascular embolization (coiling and flow diverters) in the two time periods and to examine how the results of the original BRAT have influenced the practice of neurosurgeons at the study institution. METHODS:In this retrospective cohort study, the authors evaluated patients with saccular aSAHs who were treated at a single quaternary center from August 1, 2007, to July 31, 2019. The saccular aSAH diagnoses were confirmed by cerebrovascular experts. Patients were separated into two cohorts for comparison on the basis of having undergone microsurgery or endovascular intervention. The primary outcome analyzed for comparison was poor neurological outcome, defined as a modified Rankin Scale (mRS) score > 2. The secondary outcomes that were compared included retreatment rates for both therapies. RESULTS:Of the 1014 patients with aSAH during the study period, 798 (79%) were confirmed to have saccular aneurysms. Neurological outcomes at ≥ 1-year follow-up did not differ between patients treated with microsurgery (n = 451) and those who received endovascular (n = 347) treatment (p = 0.51). The number of retreatments was significantly higher among patients treated endovascularly (32/347, 9%) than among patients treated microsurgically (6/451, 1%) (p < 0.001). The retreatment rate after endovascular treatment was lower in the PBRAT era (9%) than in the BRAT (18%). CONCLUSIONS:Similar to results from the BRAT, results from the PBRAT era showed equivalent neurological outcomes and increased rates of retreatment among patients undergoing endovascular embolization compared with those undergoing microsurgery. However, the rate of retreatment after endovascular intervention was much lower in the PBRAT era than in the BRAT.

BACKGROUND:Patients with intraventricular hemorrhage (IVH) are at higher risk of hydrocephalus requiring an external ventricular drain and long-term ventriculoperitoneal shunt placement. OBJECTIVE:To investigate whether intraventricular tissue plasminogen activator (tPA) administration in patients with ventricular casting due to IVH reduces shunt dependence. METHODS:Patients from the Post-Barrow Ruptured Aneurysm Trial (PBRAT) database treated for aneurysmal subarachnoid hemorrhage (aSAH) from August 1, 2010, to July 31, 2019, were retrospectively reviewed. Patients with and without IVH were compared. A second analysis compared IVH patients with and without ventricular casting. A third analysis compared patients with ventricular casting with and without intraventricular tPA treatment. The primary outcome was chronic hydrocephalus requiring permanent shunt placement. RESULTS:Of 806 patients hospitalized with aSAH, 561 (69.6%) had IVH. IVH was associated with a higher incidence of shunt placement (25.7% vs 4.1%, P < .001). In multivariable logistic regression analysis, IVH was independently associated with increased likelihood of shunt placement (odds ratio [OR]: 7.8, 95% CI: 3.8-16.2, P < .001). Generalized ventricular casting was present in 80 (14.3%) patients with IVH. In a propensity-score adjusted analysis, generalized ventricular casting was an independent predictor of shunt placement (OR: 3.0, 95% CI: 1.8-4.9, P < .001) in patients with IVH. Twenty-one patients with ventricular casting received intraventricular tPA. These patients were significantly less likely to require a shunt (OR: 0.30, 95% CI: 0.010-0.93, P = .04). CONCLUSION:Ventricular casting in aSAH patients was associated with an increased risk of chronic hydrocephalus and shunt dependency. However, this risk decreased with the administration of intraventricular tPA.

BACKGROUND:Outcomes for octogenarians and nonagenarians after an aneurysmal subarachnoid hemorrhage (aSAH) are particularly ominous, with mortality rates well above 50%. The present analysis examines the neurologic outcomes of patients ≥ 80 years of age treated for aSAH. METHOD:A retrospective review was performed of all aSAH patients treated at Barrow Neurological Institute from January 1, 2003, to July 31, 2019. Patients were placed in 2 groups by age, < 80 vs ≥ 80 years. The ≥ 80-year-old group of octogenarians and nonagenarians was subsequently analyzed to compare treatment modalities. Poor neurologic outcome was defined as a modified Rankin Scale (mRS) score of > 2. RESULTS: = 0.929, p < 0.001). Forty-three patients ≥ 80 years old were significantly more likely to be managed endovascularly than with open microsurgery (67% [n = 29] vs 33% [n = 14], p < 0.001). Compared with younger patients, those ≥ 80 years old had an increased risk of mortality and poor neurologic outcomes at follow-up. In the ≥ 80-year-old group, only 4 patients had good outcomes; none of the 4 had preexisting comorbidities, and all 4 were treated endovascularly. CONCLUSIONS:Age is a significant prognostic indicator of functional outcomes and mortality after aSAH. Most octogenarians and nonagenarians with aSAH will become severely disabled or die.

OBJECTIVE:Ophthalmic artery (OA) aneurysms are surgically challenging lesions that are now mostly treated using endovascular procedures. However, in specialized tertiary care centers with experienced neurosurgeons, controversy remains regarding the optimal treatment of these lesions. This study used propensity adjustment to compare microsurgical and endovascular treatment of unruptured OA aneurysms in experienced tertiary and quaternary settings. METHODS:The authors retrospectively reviewed the medical records of all patients who underwent microsurgical treatment of an unruptured OA aneurysm at the University of California, San Francisco, from 1997 to 2017 and either microsurgical or endovascular treatment at Barrow Neurological Institute from 2011 to 2019. Patients were categorized into two cohorts for comparison: those who underwent open microsurgical clipping, and those who underwent endovascular flow diversion or coil embolization. Outcomes included neurological or visual outcomes, residual or recurrent aneurysms, retreatment, and severe complications. RESULTS:A total of 345 procedures were analyzed: 247 open microsurgical clipping procedures (72%) and 98 endovascular procedures (28%). Of the 98 endovascular procedures, 16 (16%) were treated with primary coil embolization and 82 (84%) with flow diversion. After propensity adjustment, microsurgical treatment was associated with higher odds of a visual deficit (OR 8.5, 95% CI 1.1-64.9, p = 0.04) but lower odds of residual aneurysm (OR 0.06, 95% CI 0.01-0.28, p < 0.001) or retreatment (OR 0.12, 95% CI 0.02-0.58, p = 0.008) than endovascular therapy. No difference was found between the two cohorts with regard to worse modified Rankin Scale score, modified Rankin Scale score greater than 2, or severe complications. CONCLUSIONS:Compared with endovascular therapy, microsurgical clipping of unruptured OA aneurysms is associated with a higher rate of visual deficits but a lower rate of residual and recurrent aneurysms. In centers experienced with both open microsurgical and endovascular treatment of these lesions, the treatment choice should be based on patient preference and aneurysm morphology.

BACKGROUND:Owing to prolonged hospitalization and the complexity of care required for patients with aneurysmal subarachnoid hemorrhage (aSAH), these patients have a high risk of complications. The risk for wound infection after microsurgical treatment for aSAH was analyzed. METHODS:All patients who underwent microsurgical treatment for aSAH between August 1, 2007, and July 31, 2019, and were recorded in the Post-Barrow Ruptured Aneurysm Trial database were retrospectively reviewed. The patients were analyzed for risk factors for wound infection after treatment. RESULTS:Of 594 patients who underwent microsurgical treatment for aSAH, 23 (3.9%) had wound infections. There was no significant difference in age between patients with wound infection and patients without infection (mean, 52.6 ± 12.2 years vs. 54.2 ± 4.0 years; P = 0.45). The presence of multiple comorbidities (including diabetes, tobacco use, and obesity), external ventricular drain, ventriculoperitoneal shunt, pneumonia, or urinary tract infection was not associated with an increased risk for wound infection. Furthermore, there was no significant difference in mean operative time between patients with wound infection and those without infection (280 ± 112 minutes vs. 260 ± 92 minutes; P = 0.38). Patients who required decompressive craniectomy (DC) were at increased risk of wound infection (odds ratio, 5.0; 95% confidence interval, 1.8-14.1; P = 0.002). Among the 23 total infections, 9 were diagnosed following cranioplasty after DC. CONCLUSIONS:Microsurgical treatment for aSAH is associated with a relatively low risk of wound infection. However, patients undergoing DC may be at an increased risk for infection. Additional attention and comprehensive wound care are warranted for these patients.