Faculty Bibliography

Brainstem cavernous malformations (BSCMs) are rare and challenging neurosurgical lesions that demand a sophisticated and nuanced strategy for resection. A key element of surgical planning for BSCM resection is brainstem safe entry zones, a set of neuroanatomically defined locations where a pial resection can be executed with minimal risk to the adjacent central nervous system tracts and nuclei.^1-5 Quadrigeminal BSCMs are particularly unusual and can be accessed via the supra-, inter-, or infracollicular safe entry zones.²

OBJECTIVE:The "weekend effect" is the negative effect on disease course and treatment resulting from being admitted to the hospital during a weekend. Whether the weekend effect is associated with worse outcomes for patients treated for aneurysmal subarachnoid hemorrhage (aSAH) is unknown. We assessed neurologic outcomes of patients with aSAH admitted during the weekend versus during the week. METHODS:A retrospective database was reviewed to identify all patients with aSAH who received open or endovascular treatment from August 1, 2007, to July 31, 2019, at a quaternary center. The primary outcome was a poor neurologic outcome (modified Rankin Scale score >2). Propensity adjustment included age, sex, treatment type, Hunt and Hess grade, and Charlson Comorbidity Index. RESULTS:A total of 1014 patients (women, 703 [69.3%]; men, 311 [30.7%]; mean age, 56 [standard deviation, 14]) met inclusion criteria; 726 (71.6%) had weekday admissions, and 288 (28.4%) had weekend admissions. There was no significant difference between patients with a weekday versus a weekend admission in mean (standard deviation) time to treatment (0.85 [1.29] vs. 0.93 [1.30] days, P = 0.10) or length of stay (19 [9] vs. 19 [9] days, P = 0.04). Total cost and rates of delayed cerebral ischemia and vasospasm were similar between the admission groups, both overall and within the open and endovascular treatment cohorts. After propensity adjustment, weekend admission was not a significant predictor of a modified Rankin Scale score greater than 2 (odds ratio [95% confidence interval]; 1.12 [0.85-1.49]; P = 0.4). CONCLUSION:No difference in neurologic outcomes was associated with weekend admission among this cohort of patients with aSAH.

Endovascular embolization is the primary strategy in the management for vein of Galen malformations (VOGM). However, despite significant advances in endovascular embolization technologies and techniques, VOGMs remain very technically challenging lesions largely due to the high-flow arteriovenous shunts present in these malformations. A variety of advanced flow-control techniques can be implemented to mitigate the risk of venous escape and increase the safety and efficacy of endovascular treatment. These techniques include regionally targeted strategies (transvenous embolization and balloon-assisted transarterial embolization) and global flow-control methods (pharmacologic cardiac arrest and rapid ventricular overdrive pacing). Each of these strategies are associated with unique advantages and disadvantages, highlighting the importance of a patient-specific approach when treating these challenging lesions.

BACKGROUND:Few reports discuss variables associated with improved outcomes after middle meningeal artery (MMA) embolization for chronic subdural hematomas (cSDHs). We analyzed radiographic evidence of cSDH clearance after MMA embolization to elucidate optimal techniques, hematoma clearance rates, and suitable length of follow-up. METHODS:Patients who underwent MMA embolization for cSDH from January 1, 2018 through December 31, 2020 were analyzed. Patient characteristics, demographics, and technical procedural details were examined. Outcomes for cSDHs analyzed included complete or near-complete resolution at 30, 90, and 180 days following embolization. A multivariable logistic regression analysis identified variables predictive of rapid clearance and resolution of hematomas at 90 days. RESULTS:The study cohort comprised 66 patients with 84 treated cSDHs. The mean (SD) cSDH size differed significantly at 30-day (8.8 (4.3) mm), 90-day (3.4 (3.0) mm), and 180-day (1.0 (1.7) mm) follow-up (p<0.001). More cSDHs had complete or near-complete resolution at 180 days (92%, 67/73) than at 90 (63%, 45/72) and 30 days (18%, 15/84) post-embolization (p<0.001). Only distal embolysate penetration was independently associated with rapid clearance (OR 3.9, 95% CI 1.4 to 11.1; p=0.01) and resolution of cSDHs at 90 days (OR 5.0, 95% CI 1.7 to 14.6; p=0.003). CONCLUSION/CONCLUSIONS:Although 63% of cSDHs with MMA embolization had complete or near-complete resolution by 90 days post-procedure, 92% reached this stage by 180 days. Therefore, 90-day follow-up may be insufficient to determine the effectiveness of MMA embolization for cSDHs, particularly compared with surgical evacuation alone. Also, distal MMA penetration may be associated with more rapid hematoma clearance.

OBJECTIVE:Liver cirrhosis is associated with an increased risk of aneurysmal subarachnoid hemorrhage (aSAH). However, large studies analyzing the prognosis of cirrhotic patients after aSAH treatment are lacking. This study explores factors associated with inpatient mortality among aSAH patients with cirrhosis. METHODS:All patients who underwent open or endovascular treatment for an aSAH at a large quaternary center between January 1, 2003, and July 31, 2019, were retrospectively reviewed. Patients were grouped into cirrhosis versus noncirrhosis groups. Univariate analysis determined variables associated with inpatient mortality. Variables with P < 0.20 were included in a propensity-adjusted multivariable logistic regression analysis to predict inpatient mortality. RESULTS:A total of 1419 patients were treated for aSAH; 17 (1.2%) had confirmed cirrhosis. Inpatient mortality was significantly higher among cirrhotic patients than noncirrhotic patients (35.3% vs. 6.8%; P < 0.001). In the univariate analysis for inpatient mortality, the variables cirrhosis, age >65 years, Charlson Comorbidity Index >4, aneurysm size ≥10 mm, Hunt and Hess grade >3, Fisher grade 4, delayed cerebral ischemia (DCI), and posterior circulation aneurysm had P < 0.20 and were included in the multivariable analysis. The propensity-adjusted stepwise multivariable logistic regression analysis showed that cirrhosis (odds ratio [OR]: 12.7, 95% confidence interval [CI]: 3.3-48.7), Hunt and Hess grade >3 (OR: 3.9, 95% CI: 2.3-6.4), Fisher grade 4 (OR: 3.7, 95% CI: 1.3-10.7), and DCI (OR: 2.4, 95% CI: 1.5-3.9) were associated with inpatient mortality (P ≤ 0.01). CONCLUSIONS:Cirrhosis was a predictor of inpatient mortality among aSAH patients and was a stronger predictor than DCI or a poor Hunt and Hess grade among patients in this study.

OBJECTIVE:The additional hospital costs associated with delayed cerebral ischemia (DCI) have not been well investigated in prior literature. In this study, the total hospital cost of DCI in aneurysmal subarachnoid hemmorhage (aSAH) patients treated at a single quaternary center was analyzed. METHODS:All patients in the Post-Barrow Ruptured Aneurysm Trial treated for an aSAH between January 1, 2014, and July 31, 2019, were retrospectively analyzed. DCI was defined as cerebral infarction identified on computed tomography, magnetic resonance imaging, or autopsy after exclusion of procedure-related infarctions. The primary outcome was the difference in total cost (including hospital, discharge facility, and all follow-up) using a propensity-adjusted analysis. Propensity score covariate-adjusted linear regression analysis included age, sex, open versus endovascular treatment, Hunt and Hess score, and Charlson Comorbidity Index score. RESULTS:Of the 391 patients included, 144 (37%) had DCI. Patients with DCI had a significantly greater cost compared to patients without DCI (mean standard deviation $112,081 [$54,022] vs. $86,159 [$38,817]; P < 0.001) and a significantly greater length of stay (21 days [11] vs. 18 days [8], P = 0.003, respectively). In propensity-adjusted linear regression analysis, both DCI (odds ratio, $13,871; 95% confidence interval, $7558-$20,185; P < 0.001) and length of stay (odds ratio, $3815 per day; 95% confidence interval, $3480-$4149 per day; P < 0.001) were found to significantly increase the cost. CONCLUSIONS:The significantly higher costs associated with DCI further support the evidence that adverse effects associated with DCI in aSAH pose a significant burden to the health care system.

BACKGROUND:Ruptured anterior communicating artery (ACoA) aneurysms can be challenging to treat via an endovascular procedure. This study analyzed retreatment rates and neurological outcomes associated with ruptured ACoA aneurysms treated via endovascular coiling. METHODS:All patients with a ruptured ACoA aneurysm treated with endovascular coiling from 2003 to 2019 were retrospectively analyzed at a single center. Two comparisons were performed: no retreatment versus retreatment and coil embolization versus balloon-assisted coil embolization. Outcomes included retreatment and neurological outcome assessed via modified Rankin Scale (mRS). RESULTS:During the study period, 186 patients with ruptured ACoA aneurysms underwent coil embolization. Treatment included standard coil embolization (68.3%, n=127), balloon-assisted coiling (28.5%, n=53), and stent-assisted embolization (2.7%, n=5). Angiographic outcomes were as follows: class I, 65.1% (n=121); class II, 28.5% (n=53); and class III, 6.5% (n=12). There were no aneurysm reruptures after the index procedure. The mean (SD) mRS score was 2.7 (2.0) at last follow-up (mortality, 19 (10%)). Retreatment occurred in 9.7% (n=18). Patients with retreatment were younger with lower-grade subarachnoid hemorrhage and more favorable functional status at discharge. Patients with aneurysms >7 mm (n=36) were significantly more likely to have recurrence (22.2% vs 6.7%, P=0.005). CONCLUSIONS:Endovascular treatment of ruptured ACoA aneurysms is safe and is associated with low mortality and retreatment rates. Younger patients with favorable functional status and larger aneurysm size are more likely to be retreated. Ruptured aneurysms <4 mm, although prevalent in the study (29%), never required retreatment.

BACKGROUND:Middle meningeal artery (MMA) embolization results in fewer treatment failures than surgical evacuation for chronic subdural hematomas (cSDHs). We compared the total 1-year hospital cost for MMA embolization versus surgical evacuation for patients with cSDH. METHODS:Data for patients who presented with cSDHs from January 1, 2018, through May 31, 2020, were retrospectively reviewed. Patients were grouped by initial treatment (surgery vs MMA embolization), and total hospital cost was obtained. A propensity-adjusted analysis was performed. The primary outcome was difference in mean hospital cost between treatments. RESULTS:Of 170 patients, 48 (28%) underwent embolization and 122 (72%) underwent surgery. cSDHs were larger in the surgical (20.5 (6.7) mm) than in the embolization group (16.9 (4.6) mm; P<0.001); and index hospital length of stay was longer in the surgical group (9.8 (7.0) days) than in the embolization group (5.7 (2.4) days; P<0.001). More patients required additional hematoma treatment in the surgical cohort (16%) than in the embolization cohort (4%; P=0.03), and more required readmission in the surgical cohort (28%) than in the embolization cohort (13%; P=0.04). After propensity adjustment, MMA embolization was associated with a lower total hospital cost compared to surgery (mean difference -$32 776; 95% CI -$52 766 to -$12 787; P<0.001). A propensity-adjusted linear regression analysis found that unexpected additional treatment was the only significant contributor to total hospital cost (mean difference $96 357; 95% CI $73 886 to $118 827; P<0.001). CONCLUSIONS:MMA embolization is associated with decreased total hospital cost compared with surgery for cSDHs. This lower cost is directly related to the decreased need for additional treatment interventions.