Detachable coil embolization for saccular posterior inferior cerebellar artery aneurysms

Microsurgical and endovascular treatment of posterior inferior cerebellar artery aneurysms: a systematic review and meta-analysis

INTRODUCTION

Posterior inferior cerebellar artery (PICA) aneurysms are uncommon vascular lesions of the posterior fossa. In addition to aneurysmal morphology, structural anatomic considerations may confer additional procedural risk, and as a result there is currently no consensus as to whether a surgical or endovascular approach offers greater safety and efficacy for patients.

EVIDENCE ACQUISITION

We systematically examined peer-reviewed literature describing PICA aneurysm treatment planning from January 2000 to May 2021 using the PRISMA methodology. A meta-analysis of proportions was performed. Certainty of the evidence was assessed using the GRADE approach.

EVIDENCE SYNTHESIS

Fifty-eight studies including 1673 PICA aneurysms were analyzed. Overall treatment occlusion rate was 97% (95% confidence interval [CI]: 93-100%) for surgery and 85% (95% CI: 78-92%) for endovascular therapy. The recurrence rate was 6% in the endovascular group and 1% for surgery. Overall morbidity and mortality were 16% and 7%, respectively. Intraoperative complications occurred in 9% of the surgical patients.

CONCLUSIONS

Despite a large body of literature, analysis indicates that 62% of studies had moderate or serious risk of bias, suggesting very-low certainty results. Therefore, treatment via either approach should be determined on a case-by-case basis and according to institutional experience.

Technical Consideration for Coiling of Ruptured Proximal Posterior Inferior Cerebellar Artery Aneurysm

Objective

Surgical obliteration of ruptured aneurysm of the proximal posterior inferior cerebellar artery (PICA) is challenging because of limited surgical accessibility. In recent years, coil embolization is the first-choice treatment for these lesions. However, coil embolization is not always easy in ruptured PICA aneurysm owing to the variable anatomical diversity of its shapes, its relationship to the parent artery, its low incidence, and accordingly, lesser neurointerventionist experience.

Methods

The parent artery and microcatheter for easier navigation and the embolization technique for stable coiling were identified.

Results

This study aimed to identify the more appropriate approach route, microcatheter, and strategies for an easier and safer, and more durable coil embolization in the treatment of lesions in the proximal PICA.

Conclusion

Coil embolization for aneurysmal subarachnoid hemorrhage due to a ruptured proximal PICA remains a challenge, but with the appropriate coiling plan, it can be treated successfully.

Safety and efficacy of treatment strategies for posterior inferior cerebellar artery aneurysms: a systematic review and meta-analysis

INTRODUCTION

We conducted a systematic review of the literature to evaluate the safety and efficacy of treatment strategies for PICA aneurysms.

METHODS

A systematic search of Medline, EMBASE, Scopus, and Web of Science was done for studies published through November 2015. We included studies that described treatment of PICA aneurysms with ≥10 patients. Random-effects meta-analysis was used to pool the following outcomes: complete occlusion, technical success, periprocedural morbidity/mortality, stroke rates, aneurysm recurrence/rebleed, CN palsies rates, and long-term neurological morbidity/mortality.

RESULTS

We included 29 studies with 796 PICA aneurysms. When considering all ruptured PICA aneurysms, complete occlusion rates were 97.1 % (95 % CI = 94.5-99.0 %) in the surgical group and 84.3 % (95 % CI = 73.8-92.6 %) in the endovascular group. Aneurysm recurrence occurred in 1.4 % (95 % CI = 0.3-3.3 %) after surgery and in 6.9 % (95 % CI = 3.6-10.9 %) after endovascular treatment. Overall neurological morbidity and mortality were 14.4 % (95 % CI = 8.7-21.2 %) and 9.8 % (95 % CI = 5.8-14.8 %) after surgery and 15.1 % (95 % CI = 10.5-20.2 %) and 17.1 % (95 % CI = 11.5-23.7 %) after endovascular treatment, respectively. When considering all unruptured PICA aneurysms, complete occlusion rates were 92.9 % (95 % CI = 79.5-100 %) in the surgical group and 75.7 % (95 % CI = 45.4-97.1 %) in the endovascular group. Overall long-term good neurological outcome rates were 91.5 % (95 % CI = 74.4-100 %) in the surgical series and 93.3 % (95 % CI = 82.7-99.5 %) in the endovascular group.

CONCLUSIONS

Our meta-analysis demonstrated that both treatment modalities are technically feasible with high rates of technical success and effective with sufficient long-term aneurysm occlusion rates. Our data suggest that surgery is associated with superior angiographic outcomes. While endovascular therapy could be a reasonable first-line treatment option for proximal PICA aneurysms, surgery remains a highly effective first-line choice for distal PICA aneurysms. These findings should be considered when deciding the best therapeutic strategy.

Endovascular treatment of posterior inferior cerebellar artery aneurysms: a 7-year single-center experience

Aim

To report our experience with endovascular treatment of posterior inferior cerebellar artery (PICA) aneurysms.

Methods

Between January 2007 and December 2014, 40 patients with 42 PICA aneurysms were treated with endovascular embolization at our institution. Twenty-eight patients had 29 saccular aneurysms and 12 patients had 13 fusiform/dissecting aneurysms. The endovascular modalities were: (1) selective occlusion of the aneurysm with or without stent assistance (n=19); (2) occlusion of the aneurysm and the parent artery (n=22); and (3) occlusion of the aneurysm including the vertebral artery and PICA origin (n=1). Specifically, selective embolization was performed in 93.3% of aneurysms (14/15) proximal to the telovelotonsillary segment.

Results

Immediate angiographic results included 31 complete occlusions (74%), 3 nearly complete occlusions (7%), and 8 incomplete occlusions (19%). Mean follow-up of 20 months in 31 aneurysms showed 27 stable results, 3 further thromoboses, and 1 recurrence. Final results included 27 complete occlusions (87.1%) and 4 incomplete occlusions (12.9%). There were 5 overall procedural-related complications (12.5%), including 1 infarction (2.5%) and 4 intraprocedural ruptures (10.0%). Procedure-related morbidity and morbidity was 5.0% (2/40) and 2.5% (1/40), respectively. Clinical outcome was excellent (Glasgow Outcome Scale 5 in 31 of 33 patients at long-term follow-up).

Conclusions

PICA aneurysms may be effectively treated by different endovascular approaches with favorable clinical and radiologic outcomes. Further studies are required to compare the safety and efficacy of endovascular treatment with open surgery.

Coil embolization of ruptured thrombosed distal superior cerebellar artery aneurysm: a case report

Distal thrombosed aneurysm of the superior cerebellar artery (SCA) is extremely rare and is often associated with cerebellar infarction or subarachnoid hemorrhage. We report herein on a case involving a patient with a ruptured thrombosed distal SCA aneurysm which was treated successfully through the endovascular approach.

Bilateral Approach for Stent-assisted Coiling of Posterior Inferior Cerebellar Artery Aneurysms - Two Cases

Aneurysms of the posterior inferior cerebellar artery (PICA) are rarely encountered. In particular, due to frequent anatomic complexity and the presence of nearby critical structures, PICA origin aneurysms are difficult to treat. However, recent reports of anecdotal cases using advanced endovascular instruments and skills have made the results of endovascular treatment rather outstanding. PICA preservation is the key to a successful endovascular treatment, based on the premise that a PICA origin aneurysm is well occluded. To secure PICA flow, stenting into the PICA would be the best method, however, it is nearly impossible technically via the ipsilateral vertebral artery (VA) if the PICA arose at an acute angle from the sac. In such a case, a bilateral approach for stent-assisted coiling can be a creative method for achievement of two goals of both aneurysm occlusion and PICA preservation: ipsilateral approach for coil delivery and contralateral cross-over approach for stent delivery via a retrograde smooth path into the PICA.

A case of lateral medullary infarction after endovascular trapping of the vertebral artery dissecting aneurysm

We report an unusual case of lateral medullary infarction after successful embolization of the vertebral artery dissecting aneurysm (VADA). A 49-year-old man who had no noteworthy previous medical history was admitted to our hospital with a severe headache. Computed tomography (CT) revealed a subarachnoid hemorrhage, located in the basal cistern and posterior fossa. Cerebral angiography showed a VADA, that did not involve the origin of the posterior inferior cerebellar artery (PICA). We treated this aneurysm via endovascular trapping of the vertebral artery distal to the PICA. After operation, CT revealed post-hemorrhagic hydrocephalus, which we resolved with a permanent ventriculoperitoneal shunt procedure. Postoperatively, the patient experienced transient mild hoarsness and dysphagia. Magnetic resonance image (MRI) showed a small infarction in the right side of the medulla. The patient recovered well, though he still had some residual symptom of dysphagia at discharge. Such an event is uncommon but can be a major clinical concern. Further investigation to reveal risk factors and/or causative mechanisms for the medullary infarction after successful endovascular trapping of the VADA are sorely needed, to minimize such a complication.

Endoscopic endonasal clipping of a ruptured vertebral-posterior inferior cerebellar artery aneurysm: technical case report

BACKGROUND AND IMPORTANCE

Aneurysms arising from the vertebral and posterior inferior cerebellar artery complex account for only 0.5 to 3% of all aneurysms. Surgery for these aneurysms is technically challenging because of the deep location and intimate relation with the medulla and lower cranial nerves. The authors report the case of a patient with a right vertebral-posterior inferior cerebellar artery complex (VA-PICA) aneurysm that was successfully clipped via an extended endoscopic endonasal transclival approach.

CLINICAL PRESENTATION

A 74-year-old woman with the sudden onset of severe headache, nausea, and vomiting was admitted to our hospital. A computed tomography (CT) of the brain revealed diffuse subarachnoid hemorrhage associated with intraventricular hemorrhage and incipient hydrocephalus. Cerebral angiography revealed a 1.2-mm aneurysm arising at the origin of the right PICA. The aneurysm was considered unsuitable for selective coil embolization, so neck clipping was performed. With the use of an extended endoscopic endonasal transclival approach, the aneurysm was accurately reached endoscopically and successfully clipped from the parent artery. The patient was discharged neurologically intact.

CONCLUSION

To the best of the authors' knowledge, this is the first report of a successfully treated VA-PICA ruptured aneurysm using a pure endoscopic endonasal transclival approach. Endoscopic surgery may be added to the armamentarium of procedures for the treatment of posterior circulation aneurysms.