Ruptured basilar artery perforator aneurysm: A two-case correspondence of this rare phenomenon
Year: 2025
Type: article
Study design: Case Report
Abstract: Introduction Aneurysms in perforator arteries from the basilar trunk are an under-recognized cause of subarachnoid hemorrhage (SAH). They still present a challenge to conventional treatment, as excessive treatment may lead to complications due to ischemic events in neighboring perforator arteries, and the exact understanding of this phenomenon’s natural course remains elusive. Therefore, it’s imperative to make clinical decisions with precision and – in the case of surgical approach – use adequate techniques to avoid unwanted outcomes. We report two cases of patients with SAH due to basilar artery perforator aneurysms. Case Report A 69-year-old man was referred to our hospital completely lucid with severe headache, nausea, and vomiting. Computed tomography (CT) demonstrated SAH and hydrocephalus [Figure 1]. Four hours later the patient suddenly presented a decreased level of consciousness and deterioration in ventilation, being submitted to orotracheal intubation and urgently transported to our surgical center. After the placement of the external ventricular drain, a digital subtraction angiography (DSA) was conducted and showed the presence of two BAPAs [Figure 2]. Following the team’s discussion, it was determined that the best approach would be the use of a flow-diverting stent (FDS). The procedure was performed under general anesthesia, a surpass evolve was delivered through a tri-axial support system under fluoroscopic guidance (AXS Infinity Sheath 0.088 inch + AXS Catalyst 5 DAC 0.058 inch + Excelsior XT-27 microcatheter 0.036 inch; Stryker, Fremont, CA). The procedure was carried out successfully without any intercurrences [Figure 2]. Unfortunately, the patient did not regain consciousness following the procedure due to the severity of his brain lesions and succumbed to his injuries the following day.Figure 1: Diagnosis of subarachnoid hemorrhage with associated hydrocephalus. (a-c) Axial noncontrast computed tomography images at different levels, demonstrating a Fisher grade IV acute subarachnoid hemorrhageFigure 2: Diagnosis of aneurysms using digital subtraction angiography with and without 3D reconstruction. (a) Lateral view showing both aneurysms (white arrows). (b) Lateral view without 3D reconstruction showing both aneurysms (white arrow). (c) Postprocedure image showing the flow diverter stent positioning withing the aneurysm (white arrow). (d) Late postprocedure image demonstrating successful aneurysm occlusionThe second patient was a 73-year-old woman who was undergoing an investigation of a suspected cholangiocarcinoma. During the hospital stay, she presented with sudden headaches, vertigo, and mental impairment. CT head scan revealed the presence of acute SAH [Figure 3]. DSA was performed, which initially was normal. Another exam was conducted 15 days later and demonstrated a dissecting BAPA [Figure 3]. After multidisciplinary consultation, it was decided to treat the patient with FDS. However, on the day of the procedure, diagnostic angiography showed spontaneous thrombosis of the aneurysmal formation [Figure 4]. The patient recovered uneventfully from the brain hemorrhage and was neurosurgically discharged to continue with the cancer treatment. Weeks later, the patient passed away due to the progression of her cancer, which made it impossible to continue her outpatient follow-up.Figure 3: (a and b) Axial nonenhanced computed tomography images illustrating a Fisher grade IV acute subarachnoid hemorrhage. (c and d) Diagnostic digital subtraction angiography images, without and with tridimensional reconstruction, respectively, highlighting a basilar perforator aneurysm, (white arrows)Figure 4: Follow-up digital subtraction angiography showing spontaneous thrombosis of the aneurysmal formation, (a) showing an oblique view and (b) showing a lateral view, respectively.Discussion Basilar artery perforator aneurysm was first mentioned in the literature by Ghogawala et al.[1] in 1996. Besides its recognition, the number of published cases describing ruptured BAPAs treated using endovascular techniques remains notably sparse, with only up to 46 cases reported to date.[2] The anatomy of these aneurysms is a serious challenge to diagnostics. They can be easily overlooked in computed tomography and magnetic resonance imaging techniques due to their deep-seated location, small caliber, and partially thrombosed condition.[3,4] Therefore, it’s of utmost importance to include cerebral angiography in SAH cases where no lesion is found under the usual imaging. Although not yet fully understood, the physiopathology of these entities could be clarified by one theory: Dissection. The occurrence of these aneurysms at nonbranching points, the inclination to grow on acute-to-subacute stage, paired to high rates of spontaneous thrombosis and low incidence of rebleeding, suggest that dissection could be a key factor.[5] Despite being highly associated with trauma, intracranial dissections could be spontaneously caused by many predisposing factors such as atherosclerosis and hypertension. Furthermore, in light of limited evidence and a small number of BAPA case reports, there is no consensus in the treatment of this pathology. According to Kaldas et al.,[5] most of these aneurysms naturally tend to thrombose during conservative therapy, however, in cases that aneurysm growth is observed, it is prudent to not leave these cases untreated. Endovascular techniques, such as coiling and glue-based thrombotic materials, are extremely difficult to perform given the harsh anatomy of BAPAs, making the safe placement of these devices particularly challenging. Another remarkable off-label treatment possibility is the placement of FDS, which are designed to reduce enough blood flow to occlude these aneurysms prone to thrombosis, without restricting blood flow to neighboring vessels. Nevertheless, a multicenter series published by Elsheikh et al.[6] demonstrated the occurrence of ischemic events in 28% of FDS procedures, with similar high rates of ischemic complications in other endovascular techniques like stent-in-stent (20%),[7] further reinforcing the strategy of limiting the treatment only for BAPAs increase in size throughout follow-up. It is important to emphasize that we have presented two distinct cases in our study, whereas one of these featured multiple BAPAs. Faced with the challenge of managing dual BAPAs, we opted for FDS therapy despite the risks of ischemic events as demonstrated by Elsheikh et al.[6-8] We opted to intervene in this case because there are currently no documented cases in the literature concerning the treatment of multiple BAPAs, emphasizing the need for a tailored, case-by-case approach to ensure optimal patient outcomes. Conclusion Despite significant advancement in diagnostic imaging technology, basilar artery perforator aneurysms remain an under-recognized and often overlooked cause of SAH, primarily due to their complex and inaccessible anatomy. Although many BAPAs spontaneously thrombose, cases that exhibit growth are prudent to intervene. Endovascular approaches, including the use of FDS and stent-in-stent techniques, offer promise, especially in cases involving two BAPAs. However, these methods are associated with significant risks, particularly ischemic complications which often arise from the potential overtreatment. Therefore, further research into refining endovascular techniques, paired to careful monitoring and judicious treatment is essential to improve patient outcomes. The analysis of these treatment alternatives is key to developing more effective, safe approaches to managing this rare but serious condition. Author contributions Each author made significant individual contributions to this manuscript. Scaravonatto SL: Development and writing of the article; approval of the final version of the manuscript. Martio AE: Development and writing of the article; approval of the final version of the manuscript. Vanzin JR: Main physician responsible for the patient’s surgical care and main surgeon; review of the manuscript’s intellectual content; approval of the final version of the manuscript. Manzato LB: Physician responsible for the patient’s care, auxiliary surgeon; writing of the article; approval of the final version of the manuscript. Perini F: Physician responsible for the patient’s care, auxiliary surgeon; writing of the article; approval of the final version of the manuscript. Ethical policy and institutional review board statement The study was conducted in accordance with the Declaration of Helsinki. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed. Data availability statement All data generated or analyzed during this study are included in this published article. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Source: Brain Circulation
DOI: 10.4103/bc.bc_127_24
Authors: Samuel Luís Scaravonatto Baldo Cunha, Artur Eduardo Martio, Luciano Bambini Manzato, Felipe Perini, José Ricardo Vanzin
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4411141183