Endovascular embolization versus surgical clipping in a single surgeon series of basilar artery aneurysms: a complementary approach in the endovascular era

Subtemporal Approach for the Treatment of Ruptured and Unruptured Distal Basilar Artery Aneurysms: Is There a Contemporary Use?

BACKGROUND AND OBJECTIVES

Distal basilar artery aneurysms (DBAs) are high-risk lesions for which endovascular treatment is preferred because of their deep location, yet indications for open clipping nonetheless remain. The subtemporal approach allows for early proximal control and direct visualization of critical posterior perforating arteries, especially for posterior-projecting aneurysms. Our objective was to describe our clinical experience with the subtemporal approach for clipping DBAs in the evolving endovascular era.

METHODS

This was a retrospective, single-institution case series of patients with DBAs treated with microsurgery over a 21-year period (2002-2023). Demographic, clinical, and surgical data were collected for analysis.

RESULTS

Twenty-seven patients underwent clipping of 11 ruptured and 16 unruptured DBAs with a subtemporal approach (24 female; mean age 53 years). Ten patients had expanded craniotomies for treatment of additional aneurysms. The aneurysm occlusion rate was 100%. Good neurological outcomes as defined by the modified Rankin Scale score ≤2 and Glasgow Outcome Scale score ≥4 were achieved in 21/27 patients (78%). Two patients died before hospital discharge, one from vasospasm-induced strokes and another from an intraoperative myocardial infarction.

CONCLUSION

These results demonstrate that microsurgical clip ligation of DBAs using the subtemporal approach remains a viable option for complex lesions not amenable to endovascular management.

Current research status and future of endovascular treatment for basilar artery aneurysms

Aneurysms occurring along the basilar artery (BA) account for <1% of all intracranial aneurysms. Endovascular treatment (EVT) in particular is recommended for large unruptured BA aneurysms and ruptured BA aneurysms. Given that EVT techniques vary, a detailed review of EVT for BA aneurysms is necessary. In this review, the following issues were discussed: the anatomy and anomalies of the BA, the classification of BA aneurysms, the natural history of BA aneurysms, the status of open surgery, the use of EVT for various types of BA aneurysms and the deployment of new devices. According to the findings of this review and based on our experience in treating BA aneurysms, traditional coiling EVT is still the optimal therapy for most BA aneurysms. However, in some BA aneurysms, flow diverter (FD) deployment can be used. In addition, there are also some new devices, such as intrasaccular flow disruptors and stent-like devices that can be used to treat BA aneurysms. In general, EVT can yield good clinical and angiographic outcomes for patients with BA aneurysms. In addition, recent new devices and techniques, such as new-generation FDs generated via surface modification and virtual reality simulation techniques, show promise for EVT for BA aneurysms. These devices and techniques may further improve EVT outcomes for BA aneurysms.

Half-and-Half Approach for Multiple Aneurysms at the Superior Cerebellar and Middle Cerebral Arteries

Aneurysms at the superior cerebellar artery (SCA) are commonly treated endovascularly because of their location around the basilar artery,1,2 but they are not intimately related with thalamoperforators. Therefore in younger patients, those with wide-necked aneurysms, or those with multiple ipsilateral aneurysms, surgery remains a treatment option.3 We present a 52-year-old woman with dizziness in whom multiple, unruptured intracranial aneurysms were identified. Imaging demonstrated a 9-mm right-sided SCA aneurysm and 5-mm right and mirror 3-mm left M1 segment middle cerebral artery aneurysms. The patient gave consent to undergo surgery after counseling regarding her treatment options. A pterional and temporal craniotomy was performed to allow for half-and-half subtemporal and transsylvian approaches (Video 1). Here, we discuss the nuances of the approach related to the anatomy of SCA aneurysms. The challenges of the surgery can be mediated with techniques including division of the tentorium for enhanced exposure and early proximal control with temporary clinping or the use of adenosine (cardiac arrest). Our patient remained neurologically stable postoperatively and in 1-year follow-up. SCA aneurysms are easily visualized by the subtemporal and transsylvian approaches; they are frequently located adjacent to the posterior cerebral artery above and the SCA below. A modified transcavernous approach using the orbitozygomatic craniotomy has been described for access to basilar tip aneurysms.4 While comparable, this case demonstrates the efficient workflow to clip multiple aneurysms using a single, combined approach. In patients with multiple aneurysms presenting ipsilaterally or with comorbid conditions that complicate endovascular embolization, surgery should be considered as a definitive and safe treatment strategy. The patient consented to publication.

Single Component Polymers, Polymer Blends, and Polymer Composites for Interventional Endovascular Embolization of Intracranial Aneurysms

Intracranial aneurysm is the abnormal focal dilation in brain arteries. When untreated, it can enlarge to rupture points and account for subarachnoid hemorrhage cases. Intracranial aneurysms can be treated by blocking the flow of blood to the aneurysm sac with clipping of the aneurysm neck or endovascular embolization with embolics to promote the formation of the thrombus. Coils or an embolic device are inserted endovascularly into the aneurysm via a micro-catheter to fill the aneurysm. Many embolization materials have been developed. An embolization coil made of soft and thin platinum wire called the "Guglielmi detachable coil" (GDC) enables safer treatment for brain aneurysms. However, patients may experience aneurysm recurrence because of incomplete coil filling or compaction over time. Unsatisfactory recanalization rates and incomplete occlusion are the drawbacks of endovascular embolization. So, the fabrication of new medical devices with less invasive surgical techniques is mandatory to enhance the long-term therapeutic performance of existing endovascular procedures. For this aim, the current article reviews polymeric materials including blends and composites employed for embolization of intracranial aneurysms. Polymeric materials used in embolic agents, their advantages and challenges, results of the strategies used to overcome treatment, and results of clinical experiences are summarized and discussed.

A review of the top 100 most influential articles on basilar artery aneurysms

Basilar artery aneurysms account for approximately 5% of all intracranial aneurysms. This bibliometric analysis summarizes the most-cited articles on basilar artery aneurysms and highlights the contributing articles to today's evidence-based practice. In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until August 2022. The keyword "basilar artery aneurysm" or "basilar aneurysm" was used. Our results were arranged in descending order based on the article's citation count. The 100 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact Per Paper (SNIP), and Hirsch index. The keyword-based search showed that 699 articles were published between 1888 and 2022. The top 100 articles were published between 1961 and 2019. The top 100 most cited articles collected a total of 8869 citations with an average of 89 citations per paper. The rate of self-citations accounted for an average of 4.85% of the total number of citations. The bibliometric analysis provides a quantitative overview of how medical topics and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in basilar artery aneurysms by finding the top 100 most cited papers.

Focused selection of open cerebrovascular cases for residents interested in cerebrovascular neurosurgery

INTRODUCTION

National and international trends continue to show greater emphasis on endovascular techniques for the treatment of cerebrovascular disease. The cerebrovascular neurosurgeon however must be adequately equipped to treat these patients via both open and endovascular techniques.

METHODS

The decline in open cerebrovascular cases for aneurysm clipping has forced many trainees to pursue open cerebrovascular fellowships to increase case volume. An alternative strategy has been employed at our institution, which is early identification of subspecialty focus with resident driven self-selection of open cerebrovascular cases.

RESULTS

This has allowed recent graduates to obtain enfolded endovascular training and a significant number of open cerebrovascular cases in order to obtain competence and exposure.

DISCUSSION

We advocate for further self-selection paradigms supplemented with simulation training in order to obviate the need for extended post-residency fellowships.

Partial Clipping and Multilayered Wrapping Using Collagen Matrix for Partially Thrombosed Basilar Trunk Aneurysm: A Technical Case Report

Treatment of basilar artery trunk aneurysms is still challenging today, although numerous approaches and modalities of treatment exist. The authors present a case of a patient with a partially thrombosed, ruptured basilar trunk artery aneurysm successfully treated by clipping occlusion of the rupture point and multilayered wrapping of the aneurysmal dome. A 49-year-old man presented to our emergency room with a chief complaint of altered mental status. The patient was diagnosed with subarachnoid hemorrhage (SAH). No apparent bleeding point was identified on initial 3-dimension computerized tomography (CT) angiography and digital subtraction angiography (DSA). Follow-up DSA revealed a partially thrombosed saccular aneurysm emerging from the basilar trunk. We decided to treat the aneurysm surgically with partial clipping including the bleb and wrapping via the anterior transpetrosal approach. The surgery was performed successfully without any complications, and the residual blood flow within the aneurysm diminished remarkably over time. Although direct clipping and wrapping for basilar trunk artery aneurysms is one of the most challenging operations, it is a highly effective treatment for complex aneurysms, especially if other treatments are not available.

Trends and Outcomes of Endovascular Embolization and Surgical Clipping for Ruptured Intracranial Aneurysms: A Propensity-Matched Study of 1332 Patients in the United States

OBJECTIVE

To describe recent trends in treatment and outcomes of endovascular coil embolization and microsurgical clipping treatment strategies for ruptured intracranial aneurysms.

METHODS

Using International Classification of Diseases, Tenth Revision, codes, 1332 propensity-matched patients >18 years old who underwent coiling or clipping were identified. Patient demographics, baseline characteristics, comorbidities, and clinical outcomes were evaluated within 1 year postoperatively. Pooled and individual studies of the International Classification of Diseases codes investigated differences in clinical outcomes owing to aneurysm location. Outcomes were mortality, intensive care, surgical complications, hydrocephalus, and vasospasm.

RESULTS

After propensity matching for baseline characteristics and comorbidities, 666 patients were included in the coiling and clipping cohorts. There was no significant difference in 1-year mortality between cohorts. However, incidence of intensive care, surgical/medical complications, and vasospasm was significantly lower in the pooled coiling cohort (P = 0.02, P = 0.03, and P = 0.014) compared with the clipping cohort within 1 year postoperatively. Additionally, individual International Classification of Diseases code analysis revealed that coiling of anterior communicating artery aneurysms was associated with significantly fewer surgical/medical complications and hydrocephalus (P = 0.0008 and P = 0.015) and coiling of posterior communicating artery aneurysms was associated with substantially less vasospasm treatment (P = 0.034) compared with the respective clipping cohorts.

CONCLUSIONS

Analysis revealed no difference in 1-year mortality between coiling and clipping. Clinical outcomes, including intensive care, surgical complications, and vasospasm, favored coiling regardless of aneurysm location. Patients with coiling of anterior communicating artery aneurysms had significantly less hydrocephalus and patients with coiling of posterior communicating artery aneurysms had substantially less vasospasm treatment within 1 year compared with the clipping cohort.

Unstable ventricular tachycardia requiring defibrillation from rapid ventricular pacing during basilar apex aneurysm clipping

BACKGROUND

Controlled hypotension is an important tool in the open treatment of complex intracranial aneurysms. Of the available methodologies, rapid ventricular pacing (RVP) provides titratable, sustained hypotension with a relatively safe profile.

METHOD

We report the case of a 63-year-old woman who underwent a combined subfrontal and subtemporal approach for clipping of anterior communicating artery and basilar apex aneurysms. RVP was used during initial dissection of the basilar apex aneurysm and perforators but caused uncontrolled ventricular tachycardia requiring synchronized defibrillation. After restoration of hemodynamic stability, the aneurysm was uneventfully clipped.

CONCLUSION

Preparation for unstable cardiac arrhythmias is needed with RVP.

Combined subtemporal and pterional approach for clipping of multiple aneurysms

Background:

Despite ongoing improvements in endovascular techniques, open surgical management of basilar apex aneurysms is occasionally necessary.[2] Critical dissection of perforating vessels from the aneurysm is facilitated by the lateral trajectory of the subtemporal approach.[1] Incorporation of additional trajectories can facilitate treatment of multiple aneurysms within the same procedure.

Case Description:

A 48-year-old woman presented with a Hunt and Hess 1 and Fisher Grade 3 subarachnoid hemorrhage from a small and broad-necked basilar apex aneurysm that was not amenable to endovascular management. An unruptured left A1-A2 anterior cerebral artery aneurysm was also noted on vascular imaging. The patient underwent a combined right subtemporal and pterional approach for sequential clipping of the basilar and anterior communicating artery aneurysms. The third nerve, running between the posterior cerebral artery and the superior cerebellar artery, guided dissection to the basilar artery in the subtemporal approach. A temporary clip was placed on a vessel-free zone of the basilar trunk during dissection of perforators off the posterior aspect of the aneurysm dome. A fenestrated clip around the right P1 segment was used to ensure complete occlusion of the aneurysm. Indocyanine green angiography was used to confirm successful clipping and patency of parent and perforating vessels. The unruptured A1-A2 aneurysm was clipped without difficulty from the pterional trajectory. The patient had an uneventful postoperative recovery with the exception of transient right third nerve palsy.

Conclusion:

As highlighted by this case, maintenance of open surgical skills for the treatment of complex aneurysms unamenable to endovascular therapies is critical.