Lateral spinal artery aneurysm associated with a posterior inferior cerebellar artery main trunk occlusion

Lateral Spinal Artery Aneurysm Causing Subarachnoid Hemorrhage: Literature Review and Case Report

Ruptured aneurysms of the lateral spinal artery (LSA) causing subarachnoid hemorrhage (SAH) are exceptionally rare. Unlike common aneurysms in the circle of Willis, LSA aneurysms present unique diagnostic and therapeutic challenges due to their complex anatomy. We reviewed the literature, examining case reports detailing LSA aneurysm occurrences, diagnoses, treatments, and complications, and our subsequent analysis highlights the clinical presentations, imaging findings, treatment methods, and anatomical features of the LSA. We identified 10 patients from 7 case reports of LSA aneurysm presenting with SAH, and combined with the present case, this comprised a total of 11 patients. An initial CT angiography identified LSA aneurysm in only 2 of 11 patients, while 5 cases were detected in transfemoral cerebral angiography. Seven patients had stenosis or occlusion of nearby arteries. Among the 10 patients treated, 7 underwent microsurgical clipping, and 3 had endovascular treatment; complications included PICA infarction and subdural hematoma. LSA aneurysms, though rare, should be considered in differential diagnoses of posterior fossa SAH. An accurate diagnosis often requires repeated imaging. It is proposed to individualize treatment strategies based on the unique anatomical structure and hemodynamic conditions of each patient, utilizing both endovascular and surgical approaches. Understanding the vascular anatomy and collateral pathways of the LSA is crucial for improving diagnostic accuracy and treatment outcomes.

Ruptured isolated spinal artery aneurysms: Case series of five patients and a review of the literature on management strategies

BACKGROUND

Aneurysms of the spinal arteries are rare entities, the majority of which are associated with other vascular lesions, such as spinal vascular malformations. Isolated spinal artery aneurysms (SAAs) are even less frequently encountered, and their incidence is largely unknown, as the literature is limited to case reports and small series. The optimal management strategy for SAAs is not well defined.

OBJECTIVE

To review the institutional experience of five patients with isolated SAAs.

METHODS

Five cases of isolated SAAs were identified at our institution, including two cases with multiple simultaneous SAAs. Clinical presentation, imaging, and management strategies for each case were reviewed. A literature review of all SAAs reported between 1950 and 2020 was performed.

RESULTS

A total of five patients with eight isolated SAAs presented to our institution: one aneurysm was lumbar in location, while the remaining seven were thoracic. Two patients were treated with glue embolization followed by laminectomy for hematoma evacuation; one was treated with only surgery; and the other two, which both had multiple lesions, were managed conservatively with interval complete regression of their aneurysms. All five patients had good neurological outcomes. Literature review found 124 patients with at least 137 isolated SAAs and revealed treatment strategies including conservative management, glue or coil embolization, muslin wrapping, and surgical resection or clipping.

CONCLUSION

Multiple management strategies exist for SAAs, and clinical consideration of patient presentation and lesion morphology determine appropriate strategy. Our case series demonstrates three of these treatment paradigms.

Aneurysms Arising from Persistent Arteries in the Vertebrobasilar Paramedian Longitudinal Axis: Two Case Reports

A 50-year-old man and a 69-year-old woman with consciousness disturbance were diagnosed to have suffered from subarachnoid hemorrhage (SAH) involving the posterior fossa. In both cases, the initial 3D CT angiogram failed to reveal the SAH source in the vertebrobasilar system. Delayed 3D rotational angiography revealed aneurysms on unfamiliar aberrant arteries. One was a dissecting aneurysm located between the proximal part of the posterior inferior cerebellar artery and the distal part of the intracranial vertebral artery. It was trapped and resected; the patient subsequently presented with lateral medullary symptoms. The other aneurysm was between the distal posterior and the distal anterior inferior cerebellar artery. It was successfully embolized; there were no complications. We think that the aberrant aneurysm-harboring vessels encountered in these two patients were primitive arteries on or adjacent to the vertebrobasilar paramedian longitudinal axis and that they persisted past the embryologic stage. Such aneurysms arising from unfamiliar persistent arteries beside the brainstem are extremely rare but must be considered when the SAH source is not detected in the trunk of the vertebrobasilar system.

Ruptured aneurysm arising at anterior spinal artery as the collateral circulation with bulbar artery supply to posterior inferior cerebellar artery treated by proximal occlusion and occipital artery-posterior inferior cerebellar artery bypass: a case report and literature review

The cases of aneurysms arising from collateral vessels that supply the posterior inferior cerebellar artery (PICA) are so exceptionally rare that there is no consensus on the optimal treatment. In this report, a patient was presented with subarachnoid hemorrhage caused by a fusiform aneurysm on the right anterior spinal artery, which formed an anastomosis network with bulbar artery and the vessels supplying to the right PICA. We chose to perform proximal occlusion on the anterior spinal and bulbar arteries, using occipital artery-PICA bypass. Our case was the first where proximal occlusion was used concurrently with vascular reconstruction to treat a ruptured aneurysm of collateral vessels supplying to PICA.

Clipping of Ruptured Aneurysm of Lateral Spinal Artery Associated with Anastomosis to Distal Posterior Inferior Cerebellar Artery: A Case Report

BACKGROUND

Arteries that anastomose with the posterior inferior cerebellar artery (PICA) can harbor aneurysms.

CASE DESCRIPTION

We present a case of a patient who suffered a subarachnoid hemorrhage as a result from an aneurysm on the left lateral spinal artery (LSA) that anastomosed to the PICA. The aneurysm was treated surgically, and the flow between the LSA and PICA was disrupted. The activated anastomotic network created a new anastomosis between the LSA and PICA, which was seen at 6 months' follow-up.

CONCLUSIONS

Careful follow-up is warranted in patients who have an activated anastomotic network because they can potentially develop aneurysms on newly created anastomoses.

Spinal aneurysms: clinicoradiological features and management paradigms

Object

Spinal aneurysms (SAs) are rare lesions. The clinicoradiological features and the exact degree of their association with comorbid conditions such as arteriovenous malformations (AVMs) and coarctation of the aorta have not been definitively described. The ideal management paradigm has not been established. The authors reviewed literature to determine the clinical patterns of presentation, management, and outcome of spinal aneurysms.

Methods

A systematic review of literature was performed using 23 separate strings. A total of 10,190 papers were screened to identify 87 papers that met the inclusion criteria. A total of 123 SAs could be included for analysis.

Results

The mean age of patients at presentation was 38 years; 10% of patients were aged less than 10 years and nearly 50% were greater than 38 years. Spinal aneurysms can be divided into 2 groups: those associated with AVMs (SA-AVMs, or Type 1 SAs) and those with isolated aneurysms (iSAs, or Type 2 SAs). Patients with Type 2 SAs were older and more likely to present with bleeding than those with Type 1 SAs. The acute syndromes can be divided into 3 groups of patients: those with spinal syndrome, those with cranial/craniospinal syndrome, and those with nonspecific presentation. Overall, 32.6% presented with angiography-negative cranial subarachnoid hemorrhage (SAH). Presentation with evidence of cord dysfunction (myelopathy/weakness/sensory loss/bladder involvement) correlated with poor outcome, as did presentation with hemorrhage and association with other comorbid conditions. Surgery and endovascular therapy both led to comparable rates of complete aneurysm obliteration for Type 2 SAs, whereas for the AVM-associated Type 1 SAs, surgery led to better rates of lesion obliteration. The authors propose a classification scheme for spinal aneurysms based on whether the lesion is solitary or is associated with a coexistent spinal AVM; this would also imply that the ideal therapy for the aneurysm would differ based on this association.

Conclusions

The clinical and radiological patterns that influence outcome are distinct for Type 1 and Type 2 SAs. The ideal treatment for Type 1 SAs appears to be excision, whereas surgery and endovascular therapy were equally effective for Type 2 SAs.