Fusiform aneurysm of the superior cerebellar artery: short review article

Management of saccular superior cerebellar artery aneurysms: The Buffalo experience case series and systematic review

BACKGROUND

Results of the management of superior cerebellar artery (SCA) aneurysms are typically reported in combination with those for all posterior circulation aneurysms. We report our experience with the management of SCA aneurysms and a systematic review of the endovascular management of these rare aneurysms.

METHODS

Patients with saccular SCA aneurysms that were not associated with arteriovenous malformations and who presented to our institute between 2000 and 2017 were identified. Patient demographics, aneurysm characteristics, interventions, and follow-up data were collected, compared, and analyzed. For the review, data including number of aneurysm treated, outcomes, follow-up, and occlusion rates were collected.

RESULTS

Mean age of the 31 identified patients was 57.4 ± 12.3 years; 19.4% were men. Mean aneurysm size was 5.1 ± 2.9 mm. Seven of 21 patients with unruptured aneurysms were managed conservatively. Ten patients (32.3%) presented with ruptured aneurysms (mean aneurysm size, 6.2 ± 3.2 mm). Treatment was successfully completed in 22 patients: 13-primary coiling, 7-stent-assisted coiling, and 2-microsurgical clipping. Complete angiographic aneurysm occlusion after primary treatments was achieved in 19 (86.4%) patients. The total complication rate among treated patients was 4.2% (1 of 24 treated aneurysms). No minor complications occurred. However, in 2 patients, coil embolization was attempted but aborted due to coil protrusion into the parent artery. Clinical and angiographic follow-up data were available for 26 observed or treated patients. Mean follow-up duration was 5.3 ± 4.5 years. Six articles met our review inclusion criteria and demonstrated similar mean treated aneurysm sizes ranging from 4.6-7.7 mm, and follow-up from these articles ranged from 15.3-50 months.

CONCLUSIONS

Endovascularly treated patients with ruptured and unruptured SCA aneurysms, of which most were <7 mm, had good clinical outcomes with minimal complications.

Tentorial Branch of the Superior Cerebellar Artery with Retrograde Flow to Partially Thrombosed Large Superior Cerebellar Artery Aneurysm

BACKGROUND

Although the tentorial branch of the superior cerebellar artery (SCA) was reported to be a frequent finding in living subjects in 1 study, its clinical relevance, especially in surgery for aneurysms, has not been elucidated. We present our experience with the tentorial branch of the SCA identified during surgical intervention of a distal SCA aneurysm and discuss its clinical relevance.

CASE DESCRIPTION

A 71-year-old woman presented with cerebral infarction in the SCA area, and a partially thrombosed, large, fusiform aneurysm was found in the lateral pontomesencephalic segment of the SCA. Despite trapping of the aneurysm, arterial flow was observed on postprocedural Doppler flow examination and indocyanine green angiography. Careful inspection of the area led to the identification of a small tentorial branch of the SCA as a retrograde feeder. Coagulation of the artery led to the successful completion of the trapping. Postoperatively, the patient did not develop new neurologic deficits.

CONCLUSIONS

This is the first report to our knowledge of a clinical association of the tentorial branch of the SCA with a distal SCA aneurysm, which played an important role in achieving complete obliteration of the aneurysm. The recognition of this small artery is potentially important for successful cure of distal SCA aneurysms.

Distal Parent Vessel Occlusion of 2 Superior Cerebellar Artery Fusiform Aneurysms: Report of 2 Cases and Literature Review

Background

Fusiform superior cerebellar artery (SCA) aneurysms are rare, and their management represents a technical challenge. In complex aneurysms, endovascular parent vessel occlusion of the SCA may be a treatment option. Here, we present 2 cases of fusiform SCA aneurysms, 1 ruptured and 1 unruptured, as well as our institution's management with parent vessel occlusion. We also provide a review of the literature.

Cases Description

Case 1: A 42-year-old male was transferred from an outside hospital with subarachnoid hemorrhage. On admission, the patient had a Glasgow Coma Scale score of 8, a Hunt and Hess grade 4, and a Fisher grade 4. A diagnostic angiogram demonstrated a right SCA fusiform lesion with proximal and distal dilatations of 1.45 mm and 5.35 mm long, respectively, likely representing a single dissecting pseudoaneurysm. The distal dilatation was coiled, resulting in parent vessel occlusion. The patient recovered clinically and was discharged in stable condition.

Case 2: A 27-year-old female was transferred from an outside hospital due to a brainstem stroke. A diagnostic angiogram revealed an S2/S3 segment left SCA fusiform lesion, likely representing a dissecting aneurysm. The patient was neurologically intact at admission and managed conservatively. At the 2-month follow-up angiogram, the dissection had extended along the length of the SCA. Consequently, the patient underwent coil embolization of the distal left SCA. At the 6-month follow-up, the vessel remained obliterated and the patient's neurologic status had improved.

Conclusions

Endovascular coil embolization of fusiform SCA aneurysms offers a reasonable and safe treatment approach.

Ruptured Distal Superior Cerebellar Artery Dissecting Aneurysm Treated with a Flow-diverting Device: Case Report and Review of Literature

Distal fusiform aneurysms of the superior cerebellar artery (SCA) are rare and present several challenges to clinicians, especially when ruptured. While several treatment options are available, including surgical clipping and endovascular coiling, numerous challenges still remain due to the presence of vital neighboring neurovascular structures. In addition, the complications that arise due to the compromise of brainstem perforators make these aneurysms difficult to treat.

This case report demonstrates the successful treatment of a ruptured fusiform aneurysm of the SCA with a flow-diverting device. We also conducted a literature review of the use of flow-diverting devices for treating such aneurysms.

When choosing a treatment modality for a ruptured aneurysm, clinicians must consider both the patient-specific variables as well as aneurysm morphology. Treatment options including microsurgical clipping, endovascular coiling, and flow diversion carry risks. Therefore, the clinician must decide which option best fits each situation. 

Revascularization of the upper posterior circulation with the anterior temporal artery: an anatomical feasibility study

OBJECTIVE In various disease processes, including unclippable aneurysms, a bypass to the upper posterior circulation (UPC) including the superior cerebellar artery (SCA) and posterior cerebral artery (PCA) may be needed. Various revascularization options exist, but the role of intracranial (IC) donors has not been scrutinized. The objective of this study was to evaluate the anatomical feasibility of utilizing the anterior temporal artery (ATA) for revascularization of the UPC. METHODS ATA-SCA and ATA-PCA bypasses were performed on 14 cadaver specimens. After performing an orbitozygomatic craniotomy and opening the basal cisterns, the ATA was divided at the M₃-M₄ junction and mobilized to the crural cistern to complete an end-to-side bypass to the SCA and PCA. The length of the recipient artery between the anastomosis and origin was measured. RESULTS Seventeen ATAs were found. Successful anastomosis was performed in 14 (82%) of the ATAs. The anastomosis point on the PCA was 14.2 mm from its origin on the basilar artery. The SCA anastomosis point was 10.1 mm from its origin. Three ATAs did not reach the UPC region due to a common opercular origin with the middle temporal artery. The ATA-SCA bypass was also applied to the management of an incompletely coiled SCA aneurysm. CONCLUSIONS The ATA is a promising IC donor for UPC revascularization. The ATA is exposed en route to the proximal SCA and PCA through the pterional-orbitozygomatic approach. Also, the end-to-side anastomosis provides an efficient and straightforward bypass without the need to harvest a graft or perform multiple or difficult anastomoses.

Subarachnoid Hemorrhage Because of Distal Superior Cerebellar Artery Dissection in Neurofibromatosis Type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) is a rare disease with an incidence of 1 in every 3000 births. Numerous studies have focused on the main function of NF1 as a tumor suppressor, whereas few have examined the cerebrovascular abnormalities observed in patients with NF1. It is worth noting that intracranial aneurysms are uncommon in this condition.

CASE DESCRIPTION

We report a case of NF1 with a dissection of the distal segment of the superior cerebellar artery. A 36-year-old woman presented with a distal superior cerebellar artery (SCA) dissection causing subarachnoid hemorrhage. Subsequently, because of the rich collateral blood flow distal to the dissection, N-butyl cyanoacrylate (NBCA) glue embolization was unsuccessful. Therefore, direct trapping of the artery was necessary. The patient was discharged after an uneventful postoperative period, and has remained without complications.

CONCLUSIONS

In the treatment of subarachnoid hemorrhage because of a distal SCA dissection in patients with NF1, NBCA glue embolization may be a safer option than microsurgery or coil embolization, in the acute phase, considering the possible vulnerability of the vessel wall, accessibility, morphology of the lesions, and the risk of developing unpredictable infarcts in the case of parent artery occlusion. However, regular reevaluation of the blood flow is necessary to monitor recurrence, given the rich collateral circulation.

Fusiform superior cerebellar artery aneurysm treated with STA-SCA bypass and trapping

BACKGROUND

Fusiform aneurysms of cerebellar arteries are rare. Different surgical techniques to address these challenging lesions have been described, and their application depends on whether the goal is to maintain the flow in the parent vessel or to occlude it.

CASE DESCRIPTION

The authors reported a case of a fusiform aneurysm located in the lateral pontomesencephalic segment of the superior cerebellar artery (SCA) in a 32-year-old man who presented with subarachnoid hemorrhage. The patient was subjected to aneurysm trapping followed by a bypass between the superficial temporal artery (STA) and SCA and had an uneventful recovery.

CONCLUSIONS

Although only a few cases of fusiform aneurysms in the supracerebellar artery have been reported in the literature, the treatment strategies adopted were diverse. In selected cases of patients in good neurological condition with ruptured fusiform aneurysms at the proximal segments of SCA and who have poor evidence of collateral supply, the possibility of a STA-SCA bypass with aneurysm trapping must be considered. A review of the current treatment modalities of this pathology is also presented.

Unexpected ruptured aneurysm during posterior fossa surgery

BACKGROUND AND IMPORTANCE

Surgery is the recommended treatment for unique significant cerebellar metastasis, particularly in cases of hydrocephalus. Complications of posterior fossa surgery are associated with high risk of morbidity and mortality. We present a unique case of unexpected peroperative rupture of a cerebellar superior artery aneurysm during posterior fossa surgery.

CLINICAL PRESENTATION

During posterior cranial fossa surgery, severe arterial bleeding occurred in front of the medulla oblongata. Immediate postoperative computed tomographic (CT) angiography revealed a fusiform aneurysm from a distal branch of the left superior cerebellar artery.

CONCLUSION

To our knowledge, this is the first reported operative case of unexpected infratentorial ruptured aneurysm during posterior fossa 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.

Endovascular management of fusiform superior cerebellar artery aneurysms: a series of three cases with review of literature

Distal superior cerebellar artery (SCA) aneurysms are rare. Fusiform aneurysms of SCA are rarer and more challenging to treat. Parent artery occlusion by endovascular coiling is the treatment option for these cases. Presence of good collateral circulation and paucity of perforators from S1 and S2 segments makes this a feasible option. From 2007 to 2010, we treated three patients (two men and one woman between the ages of 42 to 64 years) with distal fusiform SCA aneurysms using endovascular coiling. All the patients presented with symptoms of rupture and were treated in the acute phase. Informed and written high-risk consent was given by all patients prior to the procedure. Successful angiographic and clinical outcome was achieved in all three patients. Endovascular treatment of fusiform SCA aneurysms with coils is a safe and feasible option in the management of this rare entity.

Long-term follow-up of ruptured intracranial aneurysms treated by microsurgical wrapping with autologous muscle

The purpose of this study is to describe our series of nine unclippable and uncoilable ruptured aneurysms in eight patients treated by microsurgical wrapping with autologous muscle. Records were retrospectively reviewed for rebleeding rate, morbidity and mortality, changes in size or the aneurysm's configurations, and inflammatory reaction. We conducted a Medline search in the post-microsurgical era, excluding patients in whom wrapping was part of the aneurysm treatment in combination with clipping or coiling. The surgically related morbidity was 12.5%. Global mortality rate was 25% due to vasospasm (one case) and rebleeding (one case). Six patients are still alive. Rebleeding rate was 14.3% within 6 months; then, it was zero. Glasgow outcome scale (GOS) score at discharge was 1 and 4 in one patient, respectively, and 5 in the remaining six. Mean clinical follow-up was 126 months. GOS at last follow-up was 4 and 5 in 50% of patients, respectively. Mean mRS score was 0.8 at 2 months, and 2.4 at 12 months. Follow-up MR demonstrated persistence of the aneurysm's sac, without changes in size and configuration. Patients did not describe or exhibit symptoms attributable to complications inherent to the use of muscle. Microsurgical muscle-wrapping of ruptured intracranial aneurysm is safe, is associated with a low rate of acute and delayed postoperative complications and rebleeding, and could be a valid alternative for unclippable and non-amenable to endovascular procedure ruptured aneurysms.

Neonatal ruptured intracranial aneurysms: case report and literature review

INTRODUCTION

Intracranial aneurysms are exceptional in neonatal patients: There are only 16 cases previously reported. We describe the first case of neonatal posterior inferior cerebellar artery (PICA) aneurysm and review the literature.

CASE REPORT

A 7-day-old girl presented with irritability, anorexia, fever and abnormally enlarging head circumference. Computed tomography (CT) and magnetic resonance (MR) imaging demonstrated intraventricular haemorrhage, secondary hydrocephalus and a pontine cistern haematoma. A PICA aneurysm was suspected on the CT angiogram (CTA) and the diagnosis was confirmed by conventional cerebral angiography. She was successfully treated by surgical clipping of the parent vessel and excision of the aneurysm. Postoperatively, she experienced transient swallowing difficulties and required a ventriculo-peritoneal shunt for hydrocephalus. Histopathological evaluation demonstrated a calcified arterial wall with thrombosis, signs of prior haemorrhage and the absence of the internal elastic lamina.

CONCLUSION

Neonatal intracranial aneurysms are rare. Clinical presentation of subarachnoid haemorrhage in this age group is often non-specific. First-line investigation should start with transfontanelle cranial ultrasound, followed by MR angiography then CTA if necessary. Posterior circulation aneurysms and large or giant aneurysms are more frequent in neonates and children than in adults. Early diagnosis and treatment are important for improved outcome. Surgery is better tolerated than in adults.