Giant intracranial aneurysms of the posterior circulation and their relation to the brainstem: analysis of risk factors for neurological deficits

Bibliometric and visual analysis of cerebral revascularization from 1999 to 2022

Background

Cerebral revascularization is a neurosurgical procedure used to restore the cerebral collateral circulation channel. This study examines the countries, institutions, authors, journals, keywords, and references related to the disease in the field of cerebral revascularization from 1999 to 2022 from a bibliometrics perspective, evaluates the changes of knowledge structure clustering and identifies the new hot spots and new research directions in this field.

Methods

The Web of Science Core Collection (WOSCC) database and the PICOS retrieval method were used to conduct a comprehensive search for articles and reviews pertaining to cerebral revascularization. The final filtered data were bibliometrically and visually drawn using Microsoft office 365, CiteSpace (v.6.1.R2), and VOSviewer (v.1.6.18).

Results

From 1999 to 2022, a total of 854 articles pertaining to cerebral revascularization, which originated from 46 nations, 482 institutions, and 686 researchers, were extracted from the WOSCC database, and the number of publications in this field of study was rising. The United States held the highest proportion in the ranking analysis of countries, institutions, authors, and journals. By analyzing co-citations, the scientific organization of this field and the development status of frontier fields were realized. Cerebral revascularization, moyamoya disease, extracranial intracranial bypass, and occlusion are the current research focal points in the field of cerebral revascularization. Hyperperfusion and vascular disorder may also become a new study focus in this discipline in the near future.

Conclusion

Using the method of bibliometrics, this study analyzed and reviewed the articles in the field of cerebral revascularization, which enabled scholars to better comprehend the dynamic process in this field and provided a foundation for future in-depth research.

Pipeline embolization devices for the treatment of nonsaccular aneurysms in pediatric patients

Objective

Pediatric nonsaccular aneurysms are rare but challenging lesions; pipeline embolization devices (PEDs) are their potential treatment option. In this study, we aimed to evaluate the safety and efficacy of PEDs for treatment of these aneurysms.

Methods

We retrospectively selected pediatric patients with nonsaccular aneurysms treated using PEDs between June 2015 and July 2021 from our prospectively maintained database. For each patient, demographics, aneurysm characteristics, procedure details, and clinical and angiographic follow-up data were collected and summarized.

Results

This study included 16 pediatric patients with 16 nonsaccular aneurysms treated with PEDs. A median clinical follow-up time of 1,376 days was achieved in 93.75% of the patients. The complication rate of the included patients was 25%, with two patients developing mass effect, one patient undergoing major ischemic stroke, and one patient experiencing stent foreshortening after the procedure. The complete occlusion rate of aneurysms without any neurologic sequelae was 93.33%, with a median angiographic follow-up period of 246 days. The mortality rate was 6.25%.

Conclusions

The use of PEDs to treat pediatric nonsaccular aneurysms is feasible, with a high rate of complete occlusion of the aneurysm and favorable follow-up outcomes.

Levodopa-responsive Parkinsonism Caused by Recurrence of Large Basilar-tip Aneurysm after Stent-assisted Coil Embolization: A Case Report

Aneurysms of the large basilar artery (BA) occasionally cause cranial nerve palsy and motor disorder through mass effect. Since 1967, five cases of cerebral aneurysm leading to parkinsonism have been reported. Herein, we describe a rare case of progressive parkinsonism caused by the recurrence of a large aneurysm of the basilar tip after stent-assisted coil embolization. A 66-year-old man visited our hospital with an asymptomatic large aneurysm (maximum diameter, 21 mm) of the BA tip. Magnetic resonance imaging (MRI) revealed no perianeurysmal edema. Coil embolization with a Y-configuration stent with cross-placement was performed. Although thrombus formation occurred and the perforator infarction was complicated, complete occlusion was achieved. Three months later, the patient developed progressive and severe parkinsonism. MRI revealed mild enlargement of the aneurysm and perianeurysmal mesencephalic edema with minor neck recurrence. A trial administration of levodopa and additional stent-assisted coil embolization were performed. Levodopa dramatically improved parkinsonism; thus, the patient’s symptoms were controlled by a continuous levodopa regimen. In a large BA-tip aneurysm patient, moderate regrowth and minor neck recurrence occurred after initial treatment, and chronic compression of the midbrain caused secondary parkinsonism. In such cases, it is important to consider levodopa administration and therapeutic strategies to prevent recurrence or regrowth.

Short-segment Internal Trapping for Symptomatic Thrombosed Large Fusiform Vertebral Artery Aneurysms (Bird's Nest Trapping): A Technical Note

Internal trapping with coils is an established treatment of symptomatic large non-branching thrombosed fusiform vertebral artery aneurysms (VAA). However, when perforators arise near the aneurysm neck, parent artery occlusion has a high risk of causing medullary infarction. As an alternative treatment, we performed short-segment internal trapping of the artery using n-butyl-2-cyanoacrylate (NBCA) and coils (bird's nest trapping). Before treatment, perianeurysmal perforators are carefully detected using high-resolution three-dimensional rotational angiography (3DRA). Double microcatheters are advanced to the distal portion of the aneurysm through a balloon guiding catheter where coils are deployed without tight packing. Then, NBCA is injected into the coil mass, taking care to preserve perforators and significant branches. The same maneuver is repeated in the proximal portion of the aneurysm. Coil placement is avoided within the middle of the aneurysm; however, if necessary, only a small number of coils are placed to prevent worsening of mass effect. Two quinquagenarian males presented with a large thrombosed fusiform VAA that caused symptoms due to mass effect. In each case, perforators arose from the parent artery and short-segment internal trapping with NBCA and coils was performed. Symptoms improved after treatment and follow-up imaging confirmed aneurysm shrinkage with no long-time recurrence. In symptomatic large fusiform VAAs where the distance from the lesion to important perforators is extremely short, internal trapping using a combination of NBCA and coils can be more useful than conventional internal trapping.

Interhemispheric transcallosal transforaminal approach for decompression of a giant superior cerebellar artery thrombosed aneurysm: Three-dimensional operative video

Background:

Giant brain aneurysms account for approximately 5% of all intracranial aneurysms, often presenting with intraluminal thrombosis that causes a mass effect in surrounding neural structures. Although its exact growing mechanism remains unknown, they have to be treated. Despite the most recent advances in neurosurgical fields, the best treatment modality remains unknown and surgery of giant superior cerebellar artery (SCA) aneurysms still is a challenge even for the most experienced neurosurgeons, due to their deep location, surrounding perforating vessels, and intraluminal thrombosis.

Case Description:

In this video, we present the case of a 65-year-old woman with progressive hemiparesis and paresis of low cranial nerves. The symptoms were caused by a giant aneurysm located in the origin of the SCA. Despite endovascular embolization of the aneurysm and placement of a flow diverter stent, the aneurysm increased in size causing symptoms progression. In that scenario, we decided to perform a microsurgical decompression of the aneurysm thrombus and coagulation of the vasa vasorum, to reduce the mass effect and prevent the aneurysm from keep growing.

Conclusion:

Through an extensive description of the surgical anatomy, we illustrate an interhemispheric transcallosal transforaminal approach, with the removal of anterior thalamic tubercle to widely expose the aneurysm dome. The surgery was successfully performed, and the patient symptoms improved. The patient signed the Institutional Consent Form, which allows the use of her images and videos for any type of medical publications in conferences and/or scientific articles.

Unfavorable Outcomes Related to Endovascular Treatment of Giant Vertebrobasilar Aneurysms

Background: Giant vertebrobasilar aneurysms (GVBAs) have an unfavorable natural history if left untreated and often pose a sizeable challenge to endovascular treatment. The aim of this study was to analyze the angiographic and clinical outcomes of GVBAs treated by various endovascular procedures. Methods: Between January 2010 and September 2018, 27 patients with 27 GVBAs treated endovascularly were enrolled in this consecutive study. The clinical and angiographic features, treatment modalities, and outcomes were analyzed. Results: The patient cohort comprised 21 men (77.8%) and 6 women (22.2%) of mean age 42.7 ± 18.9 years (range, 6-65 years). The most common presenting symptom was compressive symptoms, present in 15 patients (55.6%). None of the GVBAs was ruptured. Of the 27 GVBAs, 23 aneurysms were dissecting aneurysm with intramural hematoma and 4 aneurysms were saccular. Regarding treatment approach, internal trapping was used in 5 aneurysms, stent-assisted coil embolization in 10, sole stenting in 4, and flow diverters in 8. Overall, 12 patients (44.4%) had an unfavorable angiographic or clinical outcome: 3 patients presented with post-operative complications and subsequent death, and 9 with poor prognosis during follow-up. Conclusions: Patients with GVBAs may not benefit from endovascular treatment. Newer-generation devices are necessary to provide more optimal therapy for the management of these complex lesions.

Delayed extensive brain edema caused by the growth of a giant basilar apex aneurysm treated with basilar artery obliteration: a case report

Background

Partially thrombosed giant aneurysms at the basilar apex (BA) artery are challenging lesions with a poor prognosis if left untreated. Here we describe a rare case of extensive brain edema after growth of a surgically treated and thrombosed giant basilar apex aneurysm.

Case presentation

We performed a proximal surgical basilar artery occlusion on a 64-year-old female with a partially thrombosed giant BA aneurysm. MRI showed no ischemic lesions but showed marked edema adjacent to the aneurysm. She had a good recovery, but 3 months after surgical occlusion, her gait deteriorated together with urinary incontinence and worsening right hemiparesis. MRI showed that the aneurysm had grown and developed intramural hemorrhage, which caused extensive brain edema and obstructive hydrocephalus. She was treated by a ventriculoperitoneal shunt placement. Follow-up MRI showed progressive brain edema resolution, complete thrombosis of the lumen and shrinkage of the aneurysm. At 5 years follow-up the patient had an excellent functional outcome.

Conclusions

Delayed growth of a surgically treated and thrombosed giant aneurysm from wall dissection demonstrates that discontinuity with the initial parent artery does not always prevent progressive enlargement. The development of transmural vascular connections between the intraluminal thrombus and adventitial neovascularization by the vasa vasorum on the apex of the BA seems to be a key event in delayed aneurysm growth. Extensive brain edema might translate an inflammatory edematous reaction to an abrupt enlargement of the aneurysm.

An autopsy report of basilar artery aneurysm flow diversion complicated by postoperative day 3 hemorrhage from vessel rupture

A middle-aged patient presented with posterior circulation symptoms attributable to a large eccentric basilar trunk aneurysm. The planned treatment was flow diversion with loose coil packing which was successfully performed using a Pipeline Flex device deployed from the basilar to the left posterior cerebral artery. The complete procedure including live biplane fluoroscopy was digitally recorded. The patient had symptomatic improvement postoperatively and was discharged on day 1. The patient suffered a cardiac arrest on postoperative day 3 secondary to massive intraventricular and subarachnoid hemorrhage. An aneurysm rupture was suspected; however, postmortem examination showed an intact aneurysm sac. The hemorrhage was attributed to a small focal rent in the distal basilar artery next to an atheromatous plaque. The Pipeline device was visible through the rent. This is an autopsy report documenting an injury to the parent artery and not the aneurysm as a source of fatal delayed subarachnoid hemorrhage following flow diversion.

An autopsy report of basilar artery aneurysm flow diversion complicated by postoperative day 3 hemorrhage from vessel rupture

A middle-aged patient presented with posterior circulation symptoms attributable to a large eccentric basilar trunk aneurysm. The planned treatment was flow diversion with loose coil packing which was successfully performed using a Pipeline Flex device deployed from the basilar to the left posterior cerebral artery. The complete procedure including live biplane fluoroscopy was digitally recorded. The patient had symptomatic improvement postoperatively and was discharged on day 1. The patient suffered a cardiac arrest on postoperative day 3 secondary to massive intraventricular and subarachnoid hemorrhage. An aneurysm rupture was suspected; however, postmortem examination showed an intact aneurysm sac. The hemorrhage was attributed to a small focal rent in the distal basilar artery next to an atheromatous plaque. The Pipeline device was visible through the rent. This is an autopsy report documenting an injury to the parent artery and not the aneurysm as a source of fatal delayed subarachnoid hemorrhage following flow diversion.