Endovascular treatment of ruptured dissecting posterior inferior cerebellar artery aneurysms

Endovascular Embolization with n-Butyl Cyanoacrylate for Ruptured Distal Posterior Inferior Cerebellar Artery Dissecting Aneurysm

Parent artery occlusion is a definitive treatment method for preventing rebleeding of dissecting aneurysms. We herein report a case of a ruptured distal posterior inferior cerebellar artery (PICA) dissecting aneurysm treated with internal trapping using n-butyl-2-cyanoacrylate (NBCA). A 65-year-old man visited our hospital with a complaint of headache and neck pain that began 1 week before his arrival. He had a history of spontaneous subarachnoid hemorrhage of unknown cause. Computed tomography of the brain revealed a small amount of subarachnoid hemorrhage, and distal subtraction angiogram showed a distal PICA dissecting aneurysm. We placed a guiding catheter in the left vertebral artery and an intermediate catheter in the PICA. A microcatheter was guided toward the proximal side of the aneurysm and was wedged into the parent artery. The dissecting aneurysm was treated with parent artery occlusion using 50% NBCA. The postoperative course was uneventful, and the patient was discharged 3 weeks after treatment without any neurological deficit. Parent artery occlusion with internal trapping using NBCA could be a safe and definitive treatment method for distal PICA dissecting aneurysms. Angiographical evaluation of the collateral network in the distal branch of PICA before embolization and wedged microcatheter technique in the parent artery are important for successful embolization using NBCA.

Endovascular treatment of posterior inferior cerebellar artery trunk aneurysm

BACKGROUND

The posterior inferior cerebellar artery (PICA) generally originates from the vertebral artery (VA) and is the most complex cerebellar artery. Aneurysms can occur at any site along the PICA trunk. Although most PICA aneurysms are located at the VA-PICA junction, a small proportion is located at the PICA trunk. Endovascular treatment (EVT) of aneurysms in the PICA trunk may be difficult and complex.

METHODS

We performed a review to expound upon EVT of PICA trunk aneurysms.

RESULTS

The PICA can be divided into five segments (p1-5); the p1-3 segments are proximal segments, and the p4-5 segments are distal segments. Most PICA trunk aneurysms are dissecting aneurysms. Sometimes, the PICA can give rise to flow-related aneurysms in association with cerebellar arteriovenous malformations. Most aneurysms of the PICA trunk require aggressive treatment, especially those that have ruptured. Currently, the EVT mainly includes selective coiling with/without stent assistance and parent artery occlusion. Recently, some new devices, such as flow diversion and Barricade and Kaneka ED coils, can be used to treat PICA trunk aneurysms. The risk of complications with EVT seems to be higher; however, most complications are only transient or mild, and some are even clinically silent. In addition, open surgery is still an important option.

CONCLUSION

For PICA trunk aneurysms, the treatment choice should be assessed on a case-by-case basis. The rate of permanent morbidity of the EVT is low. EVT is an effective method for treating PICA trunk aneurysms.

Unusual Intracranial Manifestation of Infective Endocarditis

Objective:

The mycotic aneurysm is a rare intracranial pathology seen with pre-existing infective endocarditis. It has a high mortality rate due to its risk of rupture and needs early diagnosis and treatment.

Methods:

A 23-year male patient who presented with infective endocarditis subsequently developed a left parietal-temporal intracranial haemorrhage with suspicion of aneurysm after the course of antibiotic treatment as seen on Computed Tomography (CT) scan. Digital Subtraction Angiography (DSA) revealed a ruptured fusosaccular aneurysm in the distal parietal branches of the left Middle Cerebral Artery (MCA), for which glue embolization of the distal parent artery and aneurysm was done.

Result:

The interventional endovascular procedure was done with complete obliteration of the distal parent artery, mycotic aneurysm, and normal filling of the left internal cerebral artery (ICA) branches.

Conclusion:

Mycotic intracranial aneurysms (MIA) are a rare form of cerebrovascular pathology which needs early diagnosis with endovascular intervention when rupture occurs.

Dissecting Fusiform PICA Aneurysm Repair With Trapping and an Unconventional End-to-Side Reanastomosis: 2-Dimensional Operative Video

Dissecting fusiform posterior inferior cerebellar artery (PICA) aneurysms are rare and challenging.1,2 One common treatment is occlusion of the aneurysm and parent artery via an endovascular approach without revascularization.3 Revascularization of the artery requires an open microsurgical bypass or endovascular placement of a newer-generation flow diverter.4 We present an end-to-side reanastomosis of the PICA for treatment of a dissecting fusiform left PICA aneurysm with anatomy deemed unfavorable for endovascular treatment in a 62-yr-old man with subarachnoid hemorrhage. After discussions regarding risks, benefits, and alternatives to the procedure, the family consented to surgical treatment.  A far-lateral craniotomy was performed, with partial condylectomy to widen the exposure. The cisterna magna was opened, and the dentate ligament was cut to visualize the vertebral artery. The PICA was identified and traced distally to the aneurysmal segment, which was circumferentially diseased. Perforators were noted immediately distal to the aneurysm. The aneurysm was then trapped, and the afferent artery was transected and brought to the sidewall of the distal artery. The recipient site was trapped with temporary clips, and a linear arteriotomy was made. An end-to-side reanastomosis was performed, temporary clips were removed, and hemostasis was achieved. Postoperative angiography confirmed bypass patency and preservation of the PICA perforators.  Conventional reanastomosis of the parent artery after aneurysm excision is achieved by end-to-end reanastomosis. In contrast, we performed an unconventional end-to-side reanastomosis to revascularize the PICA while leaving the efferent artery in situ to protect its medullary perforators. This bypass is an example of a fourth-generation bypass.5,6 Used with permission from the Barrow Neurological Institute, Phoenix, Arizona.

Clinical importance of the posterior meningeal artery: a review of the literature

The posterior meningeal artery, which arises from the vertebral artery, is a critical artery in neurological lesions. However, a comprehensive review of the importance of the posterior meningeal artery is currently lacking. In this study, we used the PubMed database to perform a review of the literature on the posterior meningeal artery to increase our understanding of its role in vascular lesions. The posterior meningeal artery provides the main blood supply to the paramedial and medial portions of the dura covering the cerebellar convexity. The posterior meningeal artery is often involved in dural arteriovenous fistulas occurring near the posterior fossa, and the posterior meningeal artery can be the path for transarterial embolisation or a path through which to monitor the degree of dural arteriovenous fistula embolisation. In posterior circulation ischaemia and moyamoya disease, the posterior meningeal artery can form transdural anastomoses with pial arteries at the surface of the brain, and these can help prevent ischemia. The posterior meningeal artery can also develop aneurysms, most of which are traumatic pseudoaneurysms; patients should therefore be treated in a timely manner or followed up carefully in cases of rebleeding. In addition, during a craniotomy, the posterior meningeal artery should be protected intraoperatively to avoid damaging any transdural anastomosis that may be present. In addition, when the posterior meningeal artery is the main feeding artery of an intracranial tumour, that artery is a satisfactory path for preoperative embolisation. Briefly, the posterior meningeal artery is a very important artery in neurosurgery.

Descending Branch of the Lateral Circumflex Femoral Artery Graft for Posterior Inferior Cerebellar Artery Revascularization

BACKGROUND

Posterior inferior cerebellar artery (PICA) revascularization can be achieved with relative ease when a contralateral PICA is present. However, without a contralateral PICA, identification of a suitable vessel alternative can be challenging due to a size mismatch.

OBJECTIVE

To propose the descending branch of the lateral circumflex femoral artery (DLCFA) to be an acceptable, if not preferred, arterial graft for PICA revascularization.

METHODS

Data from patients who underwent PICA revascularization with DLCFA grafts were obtained from an institutional review board-approved prospectively maintained database with informed consent from the patients.

RESULTS

Three patients, all presenting with ruptured aneurysms, were treated with PICA revascularization using the DLCFA. All cases achieved bypass patency and no ischemic events occurred during the bypass procedures. Graft spasm occurred in 2 patients. Two patients that presented with neurological deficits achieved excellent neurological outcomes and 1 suffered an anterior spinal artery stroke during a repeat endovascular treatment 1 wk after revascularization.

CONCLUSION

The DLCFA is favorable for PICA revascularization when a contralateral PICA is not a viable option.

Intracranial Bypass of Posterior Inferior Cerebellar Artery Aneurysms: Indications, Technical Aspects, and Clinical Outcomes

BACKGROUND: For some posterior inferior cerebellar artery (PICA) aneurysms, there is no constructive endovascular or direct surgical clipping option. Intracranial bypass is an alternative to a deconstructive technique.

OBJECTIVE: To evaluate the clinical features, surgical techniques, and outcome of PICA aneurysms treated with bypass and obliteration of the diseased segment.

METHODS: Retrospective review of PICA aneurysms treated via intracranial bypass was performed. Outcome measurements included postoperative stroke, cranial nerve deficits, gastrostomy/tracheostomy requirement, bypass patency, modified Rankin scale (mRS) at discharge, and mRS at 6 mo.

RESULTS: Seven patients with PICA aneurysms treated with intracranial bypass were identified. Five had fusiform aneurysms (4 ruptured, 1 unruptured), 1 had a giant partially thrombosed saccular aneurysm (unruptured), and 1 had a dissecting traumatic aneurysm (ruptured). Two aneurysms were at the anteromedullary segment, 4 at the lateral medullary segment, and 1 at the tonsillomedullary segment. Three patients underwent PICA-to-PICA side to side anastomoses, 2 PICA-to-PICA reanastomosis, 1 vertebral artery-to-PICA bypass, and 1 occipital artery-PICA bypass. Six out of 7 aneurysms were obliterated surgically and 1 with additional endovascular occlusion after the bypass. All bypasses were patent intraoperatively; 2 were later demonstrated occluded without radiological signs or symptoms of stroke. No patients had new cranial nerve deficit postoperatively. With the exception of 1 death due to pulmonary emboli 3 mo postoperatively, all others remain at a mRS ≤ 2.

CONCLUSION: Constructive bypass and aneurysm obliteration remains a viable alternative for treatment of PICA aneurysms not amenable to direct surgical clipping or to a vessel-preserving endovascular option.

Treatment Strategy for Isolated Posterior Inferior Cerebellar Artery Dissection

OBJECTIVE

Isolated dissections that develop on the posterior inferior cerebellar artery (PICA) require intensive treatment because of their potential fatality. However, because of the rarity of these dissections, the optimal treatment has not yet been established.

METHODS

We retrospectively reviewed the clinical records of all patients who underwent any PICA dissection treatment in our institute over the last 4 years. Ten patients were enrolled, including 7 patients with subarachnoid hemorrhage (SAH) and 3 with PICA territory infarction. Dissection was seen at the proximal portion in 8 patients, whereas the remaining 2 patients showed distal PICA dissecting aneurysms.

RESULTS

Among the 7 patients with hemorrhage, 5 were actively treated (trapping and bypass, 2 patients; surgical clipping, 1 patient; coil embolization, 2 patients). Conservative management was performed in the other 2 patients. Among the 3 patients with infarction, 2 received conservative treatment. Endovascular treatment was performed in 1 patient, who showed rapid progression, aneurysm formation, and conversion to massive SAH within 10 days after the initial attack. Although 7 patients showed relatively good outcomes (modified Rankin Scale score, ≤2) after 30 days of follow-up, 1 patient had a final modified Rankin Scale score of 3. In addition, the other 2 patients (1 in each group) died as a result of major SAH.

CONCLUSIONS

Given the dynamic clinical course and potential fatality of PICA dissection, meticulous evaluation, intensive treatment with a diverse range of modalities, and proper follow-up are required for patients with PICA dissection to achieve favorable outcomes.

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.

Endovascular Treatment of Dissecting Aneurysms of the Posterior Inferior Cerebellar Artery and Predictors of Outcome

BACKGROUND

Isolated dissecting aneurysms of the posterior inferior cerebellar artery (PICA) are rare lesions, which carry high risk of rebleeding and mortality. However, the existing literature concerning predictors of outcome after endovascular treatment is limited and controversial. Our present study retrospectively reviewed and analyzed the clinical outcome of endovascular treatment-ruptured PICA-dissecting aneurysms and explored the predictors of outcome.

METHODS

We retrospectively reviewed 17 consecutive patients with ruptured PICA dissecting aneurysms that underwent endovascular treatment from January 2003 to January 2014. Nine patients underwent selective coiling, whereas 7 patients underwent parent artery occlusion and 1 patient underwent stent-assisted coiling. Follow-up outcomes were evaluated using the modified Rankin Scale. The clinical outcomes of patients were categorized as favorable (modified Rankin Scale [mRS] score 0-1) or unfavorable (mRS score 2-6).

RESULTS

Favorable outcomes (mRS score 0-1) were obtained in 13 of 17 patients. Post-treatment recurrence occurred in 1 patient with selective coiling in the 15-month follow-up, and the patient received stent-assisted coiling. The only patients with stent-assisted coiling developed PICA occlusion during follow-up. Aneurysm located in distal segment usually presented with intraventricular hemorrhage (P = .015). Hypertension, coexisting hydrocephalus, and time to operation (latter than 2 weeks) were associated with unfavorable outcome.

CONCLUSIONS

Endovascular treatment of isolated dissecting aneurysm of PICA had excellent clinical outcomes, hypertension, coexisting hydrocephalus, and time to operation (latter than 2 weeks), which were associated with unfavorable outcome. Long-term follow-ups are necessary to provide stronger conclusions.

Onyx embolization in distal dissecting posterior inferior cerebellar artery aneurysms

BACKGROUND

Dissecting aneurysms located along the distal segments of the posterior inferior cerebellar artery (PICA) are extremely rare, accounting for only 0.5-0.7% of all intracranial aneurysms. Treatment of these aneurysms is challenging, both surgically and endovascularly. We present our preliminary experience and clinical data utilizing Onyx as an embolization agent in the treatment of these lesions with proximal parent artery preservation.

METHODS

7 consecutive ruptured peripheral PICA aneurysms, in 7 patients, were treated with superselective Onyx embolization at our institutions. According to the anatomical classification of Lister et al, these aneurysms were located in the lateral medullary segment (n=1), tonsillomedullary segment (n=1), and the telovelotonsillary segment (n=5) of the PICA. Technical feasibility, procedure related complications, angiographic results, follow-up diagnostic imaging, and clinical outcome were evaluated.

RESULTS

In all cases, endovascular treatment was successful, with complete occlusion of the aneurysm with proximal parent artery preservation at the final postprocedural angiogram. Procedure related complications were not observed. One patient with a poor clinical condition at admission died during the initial hospital stay due to extensive subarachnoid and intraventricular hemorrhage. No rebleeding or recanalization was noted during follow-up. Two patients had a residual moderate to severe disability at follow-up. Favorable outcomes, with no or mild disability, were observed in four of the surviving patients.

CONCLUSIONS

Angiographic, diagnostic imaging, and clinical results of our small series indicate that Onyx embolization of dissecting distal PICA aneurysms with parent artery preservation is an effective option with acceptable morbidity and mortality rate, in those cases in which surgical clipping or endovascular coiling of the aneurysmal sac is not suitable.