Faculty Bibliography

[Figure: see text].

Giant basilar apex aneurysms are associated with significant therapeutic challenges.1-6 Multiple techniques exist to treat giant basilar apex aneurysms, including direct clipping, stent-assisted coil embolization, and proximal occlusion with bypass revascularization.7-9 Hypothermic circulatory arrest was a useful adjunct for surgical repair of these aneurysms but has been abandoned because of associated risks.10,11 Rapid ventricular pacing can achieve similar aneurysm softening with minimal risks and assist in clip occlusion. This case illustrates clip occlusion of a giant, partially thrombosed, previously stent-coiled basilar apex aneurysm in a 15-yr-old boy with progressive cranial neuropathies and sensorimotor impairment. Although a wire was placed preoperatively for ventricular pacing, it was not needed during the procedure. Patient consent was obtained. A right-sided orbitozygomatic craniotomy transcavernous approach with anterior and posterior clinoidectomies was performed. The basilar quadrification was dissected, and proximal control was obtained. After aneurysm trapping, the aneurysm was incised and thrombectomized using an ultrasonic aspirator. Back-bleeding from the aneurysm was anticipated, and ventricular pacing was ready, but back-bleeding was minimal. With the coil mass left in place, stacked, fenestrated clips were applied in a tandem fashion to occlude the aneurysm neck. Indocyanine green videoangiography confirmed occlusion of the aneurysm and patency of parent and branch arteries. The patient was at a neurological baseline after the operation, with improvement in motor skills and cognition at 3-mo follow-up. This case demonstrates the use of trans-sylvian-transcavernous exposure, rapid ventricular pacing, and thrombectomy amid previous coils and stents to clip a giant, thrombotic basilar apex aneurysm. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

OBJECTIVE:The incidence and severity of stroke are disproportionately greater among Black patients. In this study, the authors sought to examine clinical outcomes among Black versus White patients after mechanical thrombectomy for stroke at a single US institution. METHODS:All patients who underwent mechanical thrombectomy at a single center from January 1, 2014, through March 31, 2020, were retrospectively analyzed. Patients were grouped based on race, and demographic characteristics, preexisting conditions, clinical presentation, treatment, and stroke outcomes were compared. The association of race with mortality was analyzed in multivariable logistic regression analysis adjusted for potential confounders. RESULTS:In total, 401 patients (233 males) with a reported race of Black (n = 28) or White (n = 373) underwent mechanical thrombectomy during the study period. Tobacco use was more prevalent among Black patients (43% vs 24%, p = 0.04), but there were no significant differences between the groups with respect to insurance, coronary artery disease, diabetes, illicit drug use, hypertension, or hyperlipidemia. The mean time from stroke onset to hospital presentation was significantly greater among Black patients (604.6 vs 333.4 minutes) (p = 0.007). There were no differences in fluoroscopy time, procedural success (Thrombolysis in Cerebral Infarction grade 2b or 3), hospital length of stay, or prevalence of hemicraniectomy. In multivariable analysis, Black race was strongly associated with higher mortality (32.1% vs 14.5%, p = 0.01). The disparity in mortality rates resolved after adjusting for the average time from stroke onset to presentation (p = 0.14). CONCLUSIONS:Black race was associated with an increased risk of death after mechanical thrombectomy for stroke. The increased risk may be associated with access-related factors, including delayed presentation to stroke centers.

BACKGROUND:Recently, middle meningeal artery (MMA) embolization has emerged as a potentially safe and effective method of treating chronic subdural hematoma (cSDH). OBJECTIVE:To report a single-center experience with MMA embolization and examines the type of embolic material used, the extent of penetration, and the number of MMA branches embolized. METHODS:A retrospective analysis of all patients with MMA embolization from 2018 through 2019 was performed. A failed outcome was defined as either surgical rescue and/or greater than 10 mm of hematoma residual or reaccumulation following embolization. RESULTS:Of 35 patients, surgery had failed for 9 (26%) and initial conservative treatment had failed for 6 (17%). Of 41 MMA embolizations, including those in six patients with bilateral cSDH who underwent bilateral MMA embolization, 29 (72%) were performed using ethylene vinyl alcohol copolymer (Onyx), 7 (17%) using particles, and 5 (12%) using n-butyl cyanoacrylate. Both the anterior and posterior MMA divisions were embolized in 29 cases (71%); distal penetration of these branches was achieved in 25 embolizations (61%). Twenty-six (63%) cSDHs completely resolved. Complete resolution was seen in 22 of 29 hematomas (76%) in which both anterior and posterior MMA branches were occluded versus 4 of 12 (33%) following single-branch embolization (p=0.014). Embolization of one cSDH (2%) failed. CONCLUSION/CONCLUSIONS:MMA embolization of cSDHs appears to be both safe and efficacious. Furthermore, embolization of both the anterior and posterior MMA branches may be associated with increased odds of complete resolution.

BACKGROUND:Transradial artery (TRA) catheterization for neuroendovascular procedures is associated with a lower risk of complications than transfemoral artery (TFA) procedures. However, the majority of literature on TRA access pertains to diagnostic procedures rather than interventional treatments. OBJECTIVE:To compare TRA and TFA approaches for cerebrovascular interventions. METHODS:All patients with an endovascular intervention performed at a single center from October 1, 2018 to December 31, 2019 were retrospectively analyzed. Patients were grouped into 2 cohorts on the basis of whether TRA or TFA access was used. Outcomes included complications, fluoroscopy times, and total contrast administered. RESULTS:A total 579 interventional treatments were performed during the 15-mo study period. TFA procedures (n = 417) were associated with a significantly higher complication rate than TRA (n = 162) procedures (43 cases [10%] vs 5 cases [3%]; P = .008). After excluding patients who underwent thrombectomy and performing a propensity adjustment (including age, sex, pathology, procedure, sheath size, and catheter size), TRA catheterization was associated with decreased odds of a complication (odds ratio, 0.25; 95% CI 0.085-0.72; P = .01), but no significant difference in the amount of contrast administered (6.7-mL increase; 95% CI, -7.2 to 20.6; P = .34) or duration of fluoroscopy (2.1-min increase; 95% CI, -2.5 to 6.7; P = .37) compared with TFA catheterization. CONCLUSION/CONCLUSIONS:Neurointerventional procedures and treatments for a variety of pathologies can be performed successfully using the TRA approach, which is associated with a lower risk of complications and no difference in fluoroscopy duration compared with the TFA approach.

A man in his 50s presented 1 month after an automobile accident with worsening headaches and an enlarging chronic left subdural haematoma (SDH). He underwent left middle meningeal artery (MMA) embolisation. Due to tortuosity at its origin, we were unable to catheterise the MMA distally. Only proximal coil occlusion at the origin was performed. Follow-up interval head CT showed an increase in the size of the SDH with new haemorrhage, worsening mass effect and midline shift. However, he remained neurologically intact. Contralateral embolisation of the right MMA was performed with a liquid embolic agent. His headaches improved, and a follow-up head CT 3 months later showed near-complete resolution of the SDH.

BACKGROUND:Spetzler-Martin (SM) grade III arteriovenous malformations (AVMs) are at the boundary of safe operability, and preoperative embolization may reduce surgical risks. OBJECTIVE:To evaluate the benefits of preoperative AVM embolization by comparing neurological outcomes in patients with grade III AVMs treated with or without preoperative embolization. METHODS:All microsurgically treated grade III AVMs were identified from 2011 to 2018 at 2 medical centers. Neurological outcomes, measured as final modified Rankin Scale scores (mRS) and changes in mRS from preoperative baseline to last follow-up evaluation, were compared in patients with and without preoperative embolization. RESULTS:Of the 102 patients with grade III AVMs who were treated microsurgically, 57 (56%) underwent preoperative embolization. Significant differences were found between the patients with and without embolization in AVM eloquence (74% vs 93%, P = .02), size ≥ 3 cm (47% vs 73%, P = .01), diffuseness (7% vs 22%, P = .04), and mean final mRS (1.1 vs 2.0, P = .005). Poor outcomes were more frequent in patients without embolization (38%) than with embolization (7%) (final mRS > 2; P < .001). Propensity-adjusted analysis revealed AVM resection without embolization was a risk factor for poor outcome (mRS score > 2; odds ratio, 4.2; 95% CI, 1.1-16; P = .03). CONCLUSION:Nonembolization of SM grade III AVMs is associated with an increased risk of poor neurological outcomes after microsurgical resection. Preoperative embolization of intermediate-grade AVMs selected because of large AVM size, surgical inaccessibility of feeding arteries, and high flow should be employed more often than anticipated, even in the context of increasing microsurgical experience with AVMs.

BACKGROUND:Recurrent intracranial tumors frequently require re-resection. Dural adhesions to the cortex increase the morbidity and duration of these revision craniotomies. OBJECTIVE:To describe the use of commercially available sterile gelatin film to prevent meningocerebral adhesions and decrease the rate of surgically induced ischemia from revision craniotomy. METHODS:This retrospective cohort study examined patients with recurrent glioma, meningioma, and metastasis who underwent re-resection at least 30 d following their initial tumor resection. Cortical surface tissue ischemia after re-resection on diffusion-weighted magnetic resonance imaging was compared for patients with (gelatin film group) and without (nongelatin film group) a history of gelatin film placement at the conclusion of their initial tumor resection. RESULTS:A total of 84 patients in the gelatin film group were compared to 86 patients in the nongelatin film group. Patient age, sex, tumor pathology, tumor volume, tumor eloquence, laterality of surgical approach, history of radiotherapy, and time interval between resections did not differ between groups. Radiographic evidence of cortical ischemia following reoperation was less prevalent in the gelatin film group (13.1% vs 32.6%; P < .01). In multivariate logistic regression analysis, no gelatin film (P < .01) and larger tumor size (P = .02) predicted cortical surface ischemia following revision craniotomy. Postoperative complications in the gelatin film and nongelatin film group otherwise did not differ. CONCLUSION:Routine placement of commercially available sterile gelatin film on the cortex prior to dural closure is associated with decreased surgically induced tissue ischemia at the time of revision tumor craniotomy.

OBJECTIVE:Middle meningeal artery (MMA) embolization is a promising treatment strategy for chronic subdural hematomas (cSDHs). However, studies comparing MMA embolization and conventional therapy (surgical intervention and conservative management) are limited. The authors aimed to compare MMA embolization versus conventional therapy for cSDHs using a propensity-adjusted analysis. METHODS:A retrospective study of all patients with cSDH who presented to a large tertiary center over a 2-year period was performed. MMA embolization was compared with surgical intervention and conservative management. Neurological outcome was assessed using the modified Rankin Scale (mRS). A propensity-adjusted analysis compared MMA embolization versus surgery and conservative management for all individual cSDHs. Primary outcomes included change in hematoma diameter, treatment failure, and complete resolution at last follow-up. RESULTS:A total of 231 patients with cSDH met the inclusion criteria. Of these, 35 (15%) were treated using MMA embolization, and 196 (85%) were treated with conventional treatment. On the latest follow-up, there were no statistically significant differences between groups in the percentage of patients with worsening mRS scores. Of the 323 total cSDHs found in 231 patients, 41 (13%) were treated with MMA embolization, 159 (49%) were treated conservatively, and 123 (38%) were treated with surgical evacuation. After propensity adjustment, both surgery (OR 12, 95% CI 1.5-90; p = 0.02) and conservative therapy (OR 13, 95% CI 1.7-99; p = 0.01) were predictors of treatment failure and incomplete resolution on follow-up imaging (OR 6.1, 95% CI 2.8-13; p < 0.001 and OR 5.4, 95% CI 2.5-12; p < 0.001, respectively) when compared with MMA embolization. Additionally, MMA embolization was associated with a significant decrease in cSDH diameter on follow-up relative to conservative management (mean -8.3 mm, 95% CI -10.4 to -6.3 mm, p < 0.001). CONCLUSIONS:This propensity-adjusted analysis suggests that MMA embolization for cSDH is associated with a greater extent of hematoma volume reduction with fewer treatment failures than conventional therapy.

BACKGROUND:Use of the far lateral transcondylar (FL) approach and vagoaccessory triangle is the standard exposure for clipping most posterior inferior cerebellar artery (PICA) aneurysms. However, a distal PICA origin or high-lying vertebrobasilar junction can position the aneurysm beyond the vagoaccessory triangle, making the conventional FL approach inappropriate. OBJECTIVE:To demonstrate the utility of the extended retrosigmoid (eRS) approach and a lateral trajectory through the glossopharyngo-cochlear triangle as the surgical corridor for these cases. METHODS:High-riding PICA aneurysms treated by microsurgery were retrospectively reviewed, comparing exposure through the eRS and FL approaches. Clinical, surgical, and outcome measures were evaluated. Distances from the aneurysm neck to the internal auditory canal (IAC), jugular foramen, and foramen magnum were measured. RESULTS:Six patients with PICA aneurysms underwent clipping using the eRS approach; 5 had high-riding PICA aneurysms based on measurements from preoperative computed tomography angiography (CTA). Mean distances of the aneurysm neck above the foramen magnum, below the IAC, and above the jugular foramen were 27.0 mm, 3.7 mm, and 8.2 mm, respectively. Distances were all significantly lower versus the comparison group of 9 patients with normal or low-riding PICA aneurysms treated using an FL approach (P < .01). All 6 aneurysms treated using eRS were completely occluded without operative complications. CONCLUSION:The eRS approach is an important alternative to the FL approach for high-riding PICA aneurysms, identified as having necks more than 23 mm above the foramen magnum on CTA. The glossopharyngo-cochlear triangle is another important anatomic triangle that facilitates microsurgical dissection.