Faculty Bibliography

Calcification of intracranial aneurysms is a well-known phenomenon. Whether microsurgical or endovascular techniques are used, calcifications may increase the difficulty of treatment. However, the implications of calcification on aneurysm biology and stability have received little attention. We review both investigational and clinical methods that are used to detect aneurysmal calcification. We also discuss the pathophysiology of aneurysm calcification, specifically the role that inflammation and smooth muscle cells play. We finally turn our attention to the clinical implications of aneurysm calcification including rupture risk and treatment considerations. Calcification may represent an important feature in the life cycle of an aneurysm and as imaging methods continue to improve, we may yet discover a biomarker for this process.

BACKGROUND:Nationwide study results have suggested varying trends in the incidence of aneurysmal subarachnoid hemorrhage (aSAH) over time. Herein, trends over time for aSAH treated at a quaternary care center are compared with low-volume hospitals. METHODS:Cases were retrospectively reviewed for patients with aSAH treated at our institution. Trend analyses were performed on the number of aSAH hospitalizations, treatment type, Charlson Comorbidity Index (CCI), Hunt and Hess grade, aneurysm location, aneurysm type, and in-hospital mortality. The National Inpatient Sample (NIS) was queried to compare the CCI scores of our patients with those of patients in low-volume hospitals (<20 aSAH/year) in our census division. RESULTS: = 0.220, P = 0.24). Mean (standard deviation) CCI for small-volume hospitals treating aSAH within our division was significantly lower than that of our patient population (1.8 [1.6] vs 2.1 [2.0]) for 2012-2015. CONCLUSIONS:A decreasing number of patients were hospitalized with aSAH throughout the study. Compared with patients with aSAH admitted in 2004, those admitted more recently were sicker in terms of preexisting comorbidity and neurologic complexity. These trends could be attributable to the increasing availability of neurointerventional services at smaller-volume hospitals capable of treating healthier patients.

BACKGROUND:Patients with aneurysmal subarachnoid hemorrhage (aSAH) frequently suffer from vasospasm. We analyzed the association between absence of early angiographic vasospasm and early discharge. METHODS:All aSAH patients treated from August 1, 2007, to July 31, 2019, at a single tertiary center were reviewed. Patients undergoing diagnostic digital subtraction angiography (DSA) on post-aSAH days 5 to 7 were analyzed; cohorts with and without angiographic vasospasm (angiographic reports by attending neurovascular surgeons) were compared. Primary outcome was hospital length of stay; secondary outcomes were intensive care unit length of stay, 30 day return to the emergency department (ED), and poor neurologic outcome, defined as a modified Rankin Scale (mRS) score >2. RESULTS:A total of 298 patients underwent DSA on post-aSAH day 5, 6, or 7. Most patients (n=188, 63%) had angiographic vasospasm; 110 patients (37%) did not. Patients without vasospasm had a significantly lower mean length of hospital stay than vasospasm patients (18.0±7.1 days vs 22.4±8.6 days; p<0.001). The two cohorts did not differ significantly in the proportion of patients with mRS scores >2 at last follow-up or those returning to the ED before 30 days. After adjustment for Hunt and Hess scores, Fisher grade, admission Glasgow Coma Scale score, and age, logistic regression analysis showed that the absence of vasospasm on post-aSAH days 5-7 predicted discharge on or before hospital day 14 (OR 3.4, 95% CI 1.8 to 6.4, p<0.001). CONCLUSION/CONCLUSIONS:Lack of angiographic vasospasm 5 to 7 days after aSAH is associated with shorter hospitalization, with no increase in 30 day ED visits or poor neurologic outcome.

BACKGROUND:levels and adverse cardiovascular outcomes in patients treated with drug-eluting stents. However, omeprazole use among patients treated with flow-diverting stents for intracranial aneurysms has not been evaluated. METHODS:levels, and thorough documentation of administration of other medications, including omeprazole. RESULTS:level >180 PRU in the omeprazole cohort (14 of 16 [88%] vs 24 of 122 [20%]; P<0.001; OR [95% CI], 29 [6-134]). CONCLUSION/CONCLUSIONS:reactivity level among patients with intracranial aneurysms treated with flow-diverting devices who received clopidogrel. However, receipt of omeprazole was not associated with an increased risk of ischemic events or stent stenosis. For neuroendovascular patients who are treated with a flow diverter while receiving clopidogrel, alternative gastrointestinal medication regimens should be considered.

With the rapid advancements in endovascular therapy over previous decades, the treatment of spinal arteriovenous malformations (AVMs) continues to evolve. The decision to use endovascular versus surgical therapy largely depends on the type of lesion and its anatomic location. Recent studies demonstrate that endovascular treatment is effective for extradural arteriovenous fistulas (AVFs), intradural ventral (perimedullary) AVMs, and intramedullary spinal AVMs. Treatment of intradural dorsal (dural) AVFs remains largely surgical because of lower recurrence rates, although recent studies demonstrate equivocal outcomes. Extradural-intradural (juvenile) AVMs and conus AVMs remain difficult-to-treat lesions.

BACKGROUND:Transradial arterial access (TRA) for cerebral diagnostic angiography is associated with fewer access site complications than transfemoral access (TFA). However, concerns about increased procedure time and radiation exposure with TRA may slow its adoption. Our objective was to measure TRA rates of success and fluoroscopy time per vessel after 'radial-first' adoption and to compare these rates to those obtained with TFA. METHODS:We examined 500 consecutive cerebral angiograms on an intent-to-treat basis during the first full year of radial-first adoption, recording patient and procedural characteristics and outcomes. RESULTS:Over a 9-month period at a single center, 457 of 500 angiograms (91.4%) were performed with intent-to-treat via TRA, and 431 cases (86.2%) were ultimately performed via TRA. One patient (0.2%) experienced a temporary neurologic deficit in the TRA group, and none (0%) did in the TFA group (p=0.80). The mean±SD fluoroscopy time per vessel decreased significantly from the first half of the study to the second half for TRA (5.0±3.8 vs 3.4±3.5 min/vessel; p<0.001), while TFA time remained unchanged (3.7±1.8 vs 3.5±1.4 min/vessel; p=0.69). The median fluoroscopy time per vessel for TRA became faster than that for TFA after 150 angiograms. CONCLUSION/CONCLUSIONS:Of 500 consecutive angiograms performed during the first full year of radial-first implementation, 86.2% were performed successfully using TRA. TRA efficiency exceeded that of TFA after 150 angiograms. Concerns about the length of procedure or radiation exposure should not be barriers to TRA adoption.

BACKGROUND:Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence. The safety benefits of TRA at a patient level may be offset at a population level by a paradoxical increase in transfemoral access (TFA) vascular access site complications (VASCs), the so-called "radial paradox." OBJECTIVE:To study the effect of TRA adoption on TFA performance and outcomes in neuroendovascular procedures. METHODS:Data were collected for all procedures performed over a 10-mo period after radial adoption at a single center. RESULTS:Over the study period, 1084 procedures were performed, including 719 (66.3%) with an intent to treat by TRA and 365 (33.7%) with an intent to treat by TFA. Thirty-two cases (4.4%) crossed over from TRA to TFA, and 2 cases (0.5%) crossed over from TFA to TRA. TFA was performed in older patients (mean [standard deviation] TFA, 63 [15] vs TRA, 56 [16] years) using larger sheath sizes (≥7 French; TFA, 56.2% vs TRA, 2.3%) ( P < .001 for both comparisons). Overall, 29 VASCs occurred (2.7%), including 27 minor (TFA, 4.6% [18/395] vs TRA, 1.3% [9/689], P = .002) and 2 major (TFA, 0.3% [1/395] vs TRA, 0.1% [1/689], P > .99) complications. Independent predictors of VASC included TFA (OR 2.8, 95% confidence interval [CI] 1.1-7.4) and use of dual antiplatelet therapy (OR 4.2, 95% CI 1.6-11.1). CONCLUSION:TFA remains an important access route, despite a predominantly radial paradigm, and is disproportionately used in patients at increased risk for VASCs. TFA proficiency may still be achieved in predominantly radial practices without an increase in femoral complications.

BACKGROUND:The ideal treatment for unruptured vertebral artery dissecting aneurysms (VADAs) and ruptured dominant VADAs remains controversial. We report our experience in the management and endovascular treatment of patients with VADAs. METHODS:Patients treated endovascularly for intradural VADAs at a single institution from January 1, 1999, to December 31, 2019, were retrospectively reviewed. Primary neurological outcomes were assessed using modified Rankin Scale (mRS) scores, with mRS >2 considered a poor neurological outcome. Additionally, any worsening (increase) in the mRS score from the preoperative neurological examination was considered a poor outcome. RESULTS:Ninety-one patients of mean (SD) age 53 (11.6) years (48 (53%) men) underwent endovascular treatment for VADAs. Fifty-four patients (59%) presented with ruptured VADAs and 44 VADAs (48%) involved the dominant vertebral artery. Forty-seven patients (51%) were treated with vessel sacrifice of the parent artery, 29 (32%) with flow diversion devices (FDDs), and 15 (17%) with stent-assisted coil embolization (stent/coil). Rates of procedural complications and retreatment were significantly higher with stent/coil treatment (complications 4/15; retreatment 6/15) than with vessel sacrifice (complications 1/47; retreatment 2/47) or FDD (complications 2/29; retreatment 4/29) (p=0.008 and p=0.002, respectively). Of 37 patients with unruptured VADAs treated, only two (5%) had mRS scores >2 on follow-up. CONCLUSION/CONCLUSIONS:Endovascular FDD treatment of VADAs appears to be associated with lower retreatment and complication rates than stenting/coiling, although further study is required for confirmation. Endovascular treatment of unruptured VADAs was safe and was associated with favorable angiographic and neurological outcomes.

BACKGROUND:The middle meningeal artery (MMA) has been implicated in chronic headaches, but no studies have examined the relationship between MMA embolization and headaches. METHODS:Patients treated with MMA embolization for a chronic subdural hematoma (cSDH) between January 1, 2018, and December 31, 2020, were retrospectively assessed. Patients with a Glasgow Coma Scale (GCS) score of 15 at discharge received a follow-up telephone call to assess their history of chronic headache, defined as a headache ≥2 years before the cSDH and symptoms ≥2 days/month. A Headache Impact Test (HIT-6) was performed during the follow-up telephone call. The primary outcome was resolution or improvement of headaches after embolization. RESULTS:Of 76 patients undergoing MMA embolization for a cSDH during the study period, 56 (74%) had a discharge GCS score of 15. Of these 56 patients, 46 (82%) responded to a follow-up telephone call and were analyzed (mean [SD] age 68 [11] years; 36 [78%] men and 10 [22%] women). Nine (20%) reported chronic headaches before embolization. With a mean (SD) follow-up of 489 (173) days, eight of the nine patients reported improvement of chronic headaches, with seven having complete resolution. For these nine patients, the mean (SD) HIT-6 score was significantly higher before embolization than after embolization (64 [7.1] vs 40 [9.1], p<0.001). CONCLUSION/CONCLUSIONS:In patients with chronic headaches who underwent MMA embolization for a cSDH, the majority reported improvement of headaches after the procedure. Future prospective studies are warranted to assess the usefulness of MMA embolization to treat chronic headaches.

Despite advances in endovascular techniques, microsurgery continues to play an important role in the treatment of cerebral aneurysms. This article reviews the history of surgical treatment of intracranial aneurysms and the evolving role of microsurgery in the endovascular era. Although endovascular tools and techniques have changed significantly since the placement of the first Guglielmi coils in 1990, with the development of endoluminal flow-diverting stents and now endosaccular flow-diverting devices, microsurgical treatment of aneurysms has also continued to evolve. Since the first treatment with Hunterian ligation by Horsley in the 1800s, surgical treatment of intracranial aneurysms has advanced significantly beginning with the introduction of the microscope and microsurgical techniques in the 1950s. More recent advances in microsurgical treatment of aneurysms include microsurgical adjuncts, such as indocyanine green angiography, adenosine, and the exoscope, as well as tailored craniotomies, retractorless surgery, and novel bypass constructs for complex aneurysms. Microsurgery continues to play an important role in the endovascular era.