Publications

Endovascular treatment of acutely ruptured wide-necked aneurysms presents well-known challenges because of the desire to avoid intracranial stenting with attendant dual antiplatelet therapy requirements. Balloon-assisted coiling (BAC) has been well described for this purpose, most commonly using a 2-microcatheter technique, with a balloon microcatheter protecting the aneurysm neck and a coiling microcatheter used to embolize the aneurysm.1,2 However, the availability of advanced double-lumen balloon microcatheters with coiling markers allows for the use of a single-microcatheter technique in select instances.3 We present the case of a patient presenting with a ruptured wide-necked posterior communicating artery aneurysm with a large posterior communicating artery arising from the neck. The aneurysm dome had sufficient height to allow BAC using a single balloon microcatheter, which was used to protect the posterior communicating artery at the neck and deploy coils in the aneurysm dome. The aneurysm was intentionally subtotally coiled and the patient was retreated with a flow-diverting stent later during the same hospitalization (Video 1). Partial coiling followed by later flow diversion is a pragmatic strategy in wide-necked ruptured aneurysms,4 and use of a single balloon microcatheter for BAC can be useful in certain situations.

BACKGROUND: We present five patients with remodeling of the adult circle of Willis in response to flow diverter stents (FDSs) at the anterior communicating artery (AComA) and the posterior communicating artery (PComA). The observed changes provide a paradigm of how flow change can institute anatomic changes in the adult circle of Willis vasculature.

CASE DESCRIPTION: In the first two cases, after placement of the FDS covering the AComA, there was an increase in size and flow of the contralateral A1-anterior cerebral artery which had previously been hypoplastic. In one of the cases, this led to the filling of the aneurysm and required placement of coils within the lesion which was curative. In case three, the FDS effect led to asymptomatic occlusion of the PComA and associated aneurysm without change of the ipsilateral P1-segement of posterior-cerebral-artery (P1-PCA) caliber. In the fourth case, the FDS covering an aneurysm with a fetal PCA arising from its neck resulted in significant reduction of the aneurysm size, persistent flow and caliber of the fetal PCA, and the hypoplastic ipsilateral P1-PCA. Finally, in the fifth case, after FDS occlusion of the PComA and aneurysm there was increasement in diameter of the ipsilateral P1-PCA that was previously hypoplastic.

CONCLUSION: The use of FDS can affect vessels covered by the device and other arteries of the circle of Willis adjacent to the FDS. The phenomena illustrated in the hypoplastic branches appear to be a compensatory response to the hemodynamic changes induced by the divertor and to the altered flow in the circle of Willis.

BACKGROUND: By 2030, nonacute subdural hematomas (NASHs) will likely be the most common cranial neurosurgery pathology. Treatment with surgical evacuation may be necessary, but the recurrence rate after surgery is as high as 30%. Minimally invasive middle meningeal artery embolization (MMAE) during the perioperative period has been posited as an adjunctive treatment to decrease the potential for recurrence after surgical evacuation. We evaluated the safety and efficacy of concurrent MMAE in a multi-institutional cohort.

METHODS: Data from 145 patients (median age 73 years) with NASH who underwent surgical evacuation and MMAE in the perioperative period were retrospectively collected from 15 institutions. The primary outcome was the rate of recurrence requiring repeat surgical intervention. We collected clinical, treatment, and radiographic data at initial presentation, after evacuation, and at 90-day follow-up. Outcomes data were also collected.

RESULTS: Preoperatively, the median hematoma width was 18 mm, and subdural membranes were present on imaging in 87.3% of patients. At 90-day follow-up, median NASH width was 6 mm, and 51.4% of patients had at least a 50% decrease of NASH size on imaging. Eight percent of treated NASHs had recurrence that required additional surgical intervention. Of patients with a modified Rankin Scale score at last follow-up, 87.2% had the same or improved mRS score. The total all-cause mortality was 6.0%.

CONCLUSION: This study provides evidence from a multi-institutional cohort that performing MMAE in the perioperative period as an adjunct to surgical evacuation is a safe and effective means to reduce recurrence in patients with NASHs.

BACKGROUND: Patients presenting with chronic subdural hematomas (cSDHs) and on antiplatelet medications for various medical conditions often complicate surgical decision making.

OBJECTIVE: To evaluate risks of preprocedural and postprocedural antiplatelet use in patients with cSDHs.

METHODS: Patients with cSDH who were treated between January 2006 and February 2022 at a single institution with surgical intervention were identified. A propensity score matching analysis was then performed analyzing length of hospitalization, periprocedural complications, reintervention rate, rebleeding risk, and reintervention rates.

RESULTS: Preintervention, 178 patients were on long-term antiplatelet medication and 298 were not on any form of antiplatelet. Sixty matched pairs were included in the propensity score analysis. Postintervention, 88 patients were resumed on antiplatelet medication, whereas 388 patients did not have resumption of antiplatelets. Fifty-five pairs of matched patients were included in the postintervention propensity score analysis. No significant differences were found in length of hospitalization (7.8 ± 4.2 vs 6.8 ± 5.4, P = .25), procedural complications (3.3% vs 6.7%, P = .68), or reintervention during the same admission (3.3% vs 5%, P = 1). No significant differences were seen in recurrence rate (9.1% vs 10.9%, P = 1) or reintervention rate after discharge (7.3% vs 9.1%, P = 1) in the postintervention group.

CONCLUSION: Preintervention antiplatelet medications before cSDH treatment do not affect length of hospitalization, periprocedural complications, or reintervention. Resumption of antiplatelet medication after cSDH procedures does not increase the rebleeding risk or reintervention rate.

OBJECTIVE: In the absence of clear guidelines and consistent natural history data, the decision to treat unruptured intracranial aneurysms (UIAs) is a matter of some controversy. Currently, decisions are often guided by a consensus of cerebrovascular specialist teams and patient preferences. It is unclear how paradigm-shifting developments in the detection and treatment of UIAs have affected the size of the UIAs that are selected for treatment. Herein, the authors aimed to study potential changes in the average size of the UIAs that were treated over time. They hypothesized that the average size of UIAs that are treated is decreasing over time.

METHODS: A systematic search of the literature was performed to identify all studies describing the size of UIAs that were treated using any modality. Scatter diagrams with trend lines were used to plot the size of the aneurysms treated over time and assess for the presence of a potentially significant trend via statistical correlation tests. Subgroup analyses based on type of treatment, country of study, and specialty of the authors were performed.

RESULTS: A total of 240 studies including 35,150 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. The mean age of patients was 55.5 years, and 70.7% of the patients were females. There was a significant decrease in the size of treated UIAs over time (Spearman's r = -0.186, p < 0.001), with a 0.71-mm decrease in the average size of treated UIAs every 5 years since 1987 and an annual mean dropping below 7 mm in 2012. This decreasing trend was present in surgically and endovascularly treated UIAs (p < 0.001 for both), in more developed and developing countries (p < 0.001 for both), within neurosurgical and non-neurosurgical specialties (p < 0.001 for both), most prominently in the US (Spearman's r = -0.482, p < 0.001), and less prominently in Europe (Spearman's r = -0.221, p < 0.001) and was not detected in East Asia.

CONCLUSIONS: The present study indicates that based on the treated UIA size data published in the literature over the past 35 years, smaller UIAs are being treated over time. This trend is likely driven by safer treatments. However, future studies should elucidate the cost-effectiveness of treating smaller UIAs as well as the possible real-world contribution of this trend in preventing aneurysmal subarachnoid hemorrhage.

Spontaneous thrombosis of giant aneurysms is a well-reported phenomenon. However, reports of complete occlusion of the aneurysm and parent vessel are scarce. Here, we describe the case of a patient with spontaneous thrombosis of a giant cavernous internal carotid artery (ICA) aneurysm and occlusion of the ICA. A 59-year-old female initially presented with frequent headaches and was otherwise completely neurologically intact. Magnetic resonance angiography (MRA) demonstrated a giant, partially thrombosed right cavernous ICA aneurysm. She was also found to have a contralateral left-sided intracavernous aneurysm. Cerebral angiogram revealed a giant, partially thrombosed right cavernous segment ICA aneurysm measuring 27.1 x 32.4 mm with slow, turbulent flow within the lesion. The patient was started on aspirin 325 mg and a dexamethasone taper with plans for follow-up flow diversion for treatment of the right cavernous ICA aneurysm. The patient presented three months later with worsening headaches, and on examination was found to have anisocoria (right > left) with a nonreactive right pupil as well as cranial nerve III/IV palsies, and facial edema. There was no evidence of intracranial hemorrhage or ischemia seen on head computed tomography (HCT). The diagnostic cerebral angiogram demonstrated complete occlusion of the right ICA at the carotid bifurcation with no filling of the giant right cavernous ICA aneurysm and a stable left cavernous ICA aneurysm. Although the exact mechanism of simultaneous thrombosis of the aneurysm and its parent artery remains unclear, it is likely due to stagnant flow. The presence of cranial nerve palsies was most likely secondary to acute edema of the lesion after thrombus formation. There was no evidence of ischemic symptoms due to collateral flow across a patent anterior communicating artery.

Background Knowledge regarding predictors of clinical and radiographic failures of middle meningeal artery (MMA) embolization (MMAE) treatment for chronic subdural hematoma (CSDH) is limited. Purpose To identify predictors of MMAE treatment failure for CSDH. Materials and Methods In this retrospective study, consecutive patients who underwent MMAE for CSDH from February 2018 to April 2022 at 13 U.S. centers were included. Clinical failure was defined as hematoma reaccumulation and/or neurologic deterioration requiring rescue surgery. Radiographic failure was defined as a maximal hematoma thickness reduction less than 50% at last imaging (minimum 2 weeks of head CT follow-up). Multivariable logistic regression models were constructed to identify independent failure predictors, controlling for age, sex, concurrent surgical evacuation, midline shift, hematoma thickness, and pretreatment baseline antiplatelet and anticoagulation therapy. Results Overall, 530 patients (mean age, 71.9 years ± 12.8 [SD]; 386 men; 106 with bilateral lesions) underwent 636 MMAE procedures. At presentation, the median CSDH thickness was 15 mm and 31.3% (166 of 530) and 21.7% (115 of 530) of patients were receiving antiplatelet and anticoagulation medications, respectively. Clinical failure occurred in 36 of 530 patients (6.8%, over a median follow-up of 4.1 months) and radiographic failure occurred in 26.3% (137 of 522) of procedures. At multivariable analysis, independent predictors of clinical failure were pretreatment anticoagulation therapy (odds ratio [OR], 3.23; P = .007) and an MMA diameter less than 1.5 mm (OR, 2.52; P = .027), while liquid embolic agents were associated with nonfailure (OR, 0.32; P = .011). For radiographic failure, female sex (OR, 0.36; P = .001), concurrent surgical evacuation (OR, 0.43; P = .009), and a longer imaging follow-up time were associated with nonfailure. Conversely, MMA diameter less than 1.5 mm (OR, 1.7; P = .044), midline shift (OR, 1.1; P = .02), and superselective MMA catheterization (without targeting the main MMA trunk) (OR, 2; P = .029) were associated with radiographic failure. Sensitivity analyses retained these associations. Conclusion Multiple independent predictors of failure of MMAE treatment for chronic subdural hematomas were identified, with small diameter (<1.5 mm) being the only factor independently associated with both clinical and radiographic failures. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Chaudhary and Gemmete in this issue.

Pseudoaneurysms are rare but devastating complications of penetrating head traumas. They require rapid surgical or endovascular intervention due to their high risk of rupture; however, complex presentations may limit treatment options. Our objective is to report a case of severe vasospasm, flow diversion, and in-stent stenosis complicating the treatment of a middle cerebral artery pseudoaneurysm following a gunshot wound. A 33-year-old woman presented with multiple calvarial and bullet fragments within the right frontotemporal lobes and a large right frontotemporal intraparenchymal hemorrhage with significant cerebral edema. She underwent an emergent right hemicraniectomy for decompression, removal of bullet fragments, and evacuation of hemorrhage. Once stable enough for diagnostic cerebral angiography, she was found to have an M1 pseudoaneurysm with severe vasospasm that precluded endovascular treatment until the vasospasm resolved. The pseudoaneurysm was treated with flow diversion and in-stent stenosis was found at 4-month follow-up angiography that resolved by 8 months post-embolization. We report the successful flow diversion of an middle cerebral artery (MCA) pseudoaneurysm complicated by severe vasospasm and later in-stent stenosis. The presence of asymptomatic stenosis is believed to be reversible intimal hyperplasia and a normal aspect of endothelial healing. We suggest careful observation and dual-antiplatelet therapy as a justified approach.

BACKGROUND AND OBJECTIVES: Studies have shown that use of statin can improve radiographic and clinical outcomes in patients receiving treatment for coronary artery or peripheral vascular stenosis. Statins are thought to be effective by reducing arterial wall inflammation. The same mechanism may have an influence on the efficacy of pipeline embolization device (PED) for intracranial aneurysm treatment. Although this question has been of interest, there is a lack of well-controlled data in the literature. The objective of this study is to analyze the effect of statins on outcomes of aneurysms treated with pipeline embolization through propensity score matching.

METHODS: Patients who underwent PED for unruptured intracranial aneurysms at our institution between 2013 and 2020 were identified. Patients on statin treatment vs those who were not were matched through propensity score by controlling for confounding factors including age, sex, current smoking status, diabetes, aneurysm morphology, volume, neck size, location of aneurysm, history of treatment for the same aneurysm, type of antiplatelet therapy, and elapsed time at last follow-up. Occlusion status at first follow up and last follow-up, and incidence of in-stent stenosis and ischemic complications during the follow-up period were extracted for comparison.

RESULTS: In total, 492 patients with PED were identified, of whom 146 were on statin therapy and 346 were not. After one-to-one nearest neighbor matching, 49 cases in each group were compared. At last follow-up, 79.6%, 10.2%, and 10.2% of cases in the statin therapy group and 67.4%, 16.3%, and 16.3% in the nonstatin group were noted to have Raymond-Roy 1, 2, and 3 occlusions, respectively ( P = .45). No significant difference was observed in immediate procedural thrombosis ( P > .99), long-term in-stent stenosis ( P > .99), ischemic stroke ( P = .62), or retreatment ( P = .49).

CONCLUSION: Statin use does not affect occlusion rate or clinical outcomes in patients treated with PED treatment for unruptured intracranial aneurysms.

BACKGROUND AND OBJECTIVES: Endovascular treatment of unruptured intracranial aneurysms (UIAs) in patients receiving anticoagulant medications has not been well studied. Whether long-term anticoagulation (AC) use affects aneurysmal obliteration rates and treatment-related complications is unclear.

METHODS: Patients with endovascular treatment for UIA from 4 academic centers were identified and divided into AC and non-AC groups. Periprocedural complications, radiographic and clinical outcomes, and retreatment rates were compared between the 2 groups before and after propensity score matching.

RESULTS: The initial cohort consisted of 70 patients in the AC group and 355 in the non-AC group. After one-to-one nearest neighbor propensity matching, 38 pairs of patients were compared for periprocedural complications. The total number of complications were higher in the AC group yet not significant (18.4% vs 5.3%, P = .15). After adding imaging follow-up duration to matched variables, 36 pairs were obtained. There was no significant difference in Raymond-Roy occlusion rate between the 2 groups ( P = .74). However, retreatment rate trended higher in the AC group compared with the non-AC group (22.2% vs 5.6%, P = .09). When clinical follow-up duration was added among matched variables, 26 pairs of cases were obtained for long-term clinical outcomes. There was no significant difference in modified Rankin Scale score between the 2 groups ( P = .61). One-to-many nearest neighbor propensities matched analysis with bigger sample sizes yielded similar results.

CONCLUSION: The use of anticoagulants does not affect occlusion rates or long-term outcomes in endovascular treatment of UIAs. Retreatment rates were higher in the AC group; however, this was not statistically significant.