Successfully Treated Isolated Posterior Spinal Artery Aneurysm Causing Intracranial Subarachnoid Hemorrhage: Case Report

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.

Repeated Retching and Vomiting in the Pathophysiology of Isolated Spinal Aneurysms

BACKGROUND

Rupture of spinal aneurysms is a rare cause of subarachnoid hemorrhage. These aneurysms are often associated with a variety of vascular malformations that increase blood flow in the spinal circulation or with disorders that compromise the vessel wall. However, spinal aneurysms may be isolated, not associated with any known predisposing condition. The objective of this study is to explore the possible mechanisms associated with the formation and rupture of isolated spinal aneurysms (ISAs).

METHODS

We conducted a retrospective review of a series of consecutive patients admitted for a ruptured ISA. In all cases, spinal angiography confirmed the presence of a spinal aneurysm responsible for the bleeding. Particular attention was paid to medical history and symptoms before bleeding, for potential factors predisposing to their formation and rupture.

RESULTS

Between 2008 and 2020, ten cases of spinal aneurysms were seen at our institution including 4 cases of ISA. All patients with ISA were female, and in 3 cases the aneurysm involved the territory of the posterior spinal artery. In 3 of these 4 (75%) ISA cases, there was a strikingly similar history of retching and vomiting preceding the thunderclap headache. In 1 patient, the aneurysm was surgically resected; pathologic analysis revealed a fusiform dissecting aneurysm. All 4 patients had a favorable outcome.

CONCLUSIONS

We suggest that the straining during prolonged retching and vomiting plays a role in the formation and rupture of some ISAs, possibly because of pressure spikes, increased transmural arterial pressure, and increased wall shear stress during straining.

An isolated ruptured spinal aneurysm presents with a thalamic Infarct: case report

BACKGROUND

Isolated spinal artery aneurysms are extremely rare, and their pathogenesis, clinical presentation, and treatment strategies are poorly established. We report only the second case of a patient with an isolated posterior spinal aneurysm and concurrent left thalamic infarct and review the literature to help clarify treatment strategies of isolated spinal aneurysms.

CASE PRESENTATION

A 49-year-old patient presented with acute onset walking difficulty followed by diaphoresis, back and abdominal pain, and paraplegia. Imaging was notable for a hemorrhagic spinal lesion with compression at T12 through L4 and an acute left thalamic infarct. Surgical exploration revealed an isolated posterior spinal artery aneurysm. The aneurysm was surgically resected and the patient had partial recovery six months post-operatively.

CONCLUSIONS

Isolated posterior spinal artery aneurysms of the thoracolumbar region are rare lesions that commonly present with abdominal pain, radiating back pain, and lower extremity weakness. Imaging may not provide a definitive diagnosis. The three primary treatment strategies are conservative management, endovascular treatment, or surgical resection. In patients with symptomatic cord compression, immediate surgical intervention is indicated to preserve neurologic function. In all other cases, the artery size, distal flow, morphology, and location may guide management.

Anatomical Study of the Posterior Spinal Artery Branches to the Medulla Oblongata

BACKGROUND

The posterior spinal arteries (PSAs), branches of the intracranial segment of the vertebral artery or posterior inferior cerebellar artery, run bilaterally along the spinal cord and are integral to the blood supply primarily to the posterior one third of this structure. However, a less well-described distribution of the PSAs is their supply to the posterior medulla. The purpose of this study is to examine the medullary branches of the PSA anatomically.

METHODS

We conducted a cadaveric study to evaluate for branches of the PSA supplying the medulla oblongata.

RESULTS

All 14 sides had medullary branches arising from the PSAs. The average number of branches supplying the medulla oblongata on each side was 6. Most of these branches traveled laterally to anastomose with medullary branches arising from the anterior spinal artery. Additionally, lateral and ascending branches were noted.

CONCLUSIONS

Physicians who interpret imaging of the craniocervical junction, in particular arteriograms, should be aware of ascending medullary branches arising from the anterior spinal artery. Additionally, neurosurgeons operating this region must be careful in dissecting over the posterior medulla and manipulating the cerebellar tonsils, as in telovelar approaches to the fourth ventricle, in order to avoid iatrogenic injury to these vessels. Additionally, variable stroke patterns involving the vertebral artery or posterior inferior cerebellar artery might include ischemia to the medulla oblongata via PSA branches, and this anatomy should be kept in mind by interventionalists, radiologists, and neurologists alike.

Ruptured Spinal Aneurysms: Diagnosis and Management Paradigms

BACKGROUND

Spinal aneurysms (SA) are rare neurovascular pathologies with an unclear natural history and management strategy. We review the clinical and radiologic manifestations, management, and outcome of patients who presented with spinal subarachnoid hemorrhage (SAH) secondary to ruptured spinal aneurysms over a 10-year period. We provide a literature review about this condition and its management.

METHODS

All patients diagnosed with nontraumatic spinal SAH were collected from a single-center prospectively maintained database of patients with SAH between January 2010 and January 2020. Patients diagnosed with spinal aneurysms were reviewed. For each patient, demographic data, clinical presentation, imaging findings, management strategies, and outcomes are reviewed and discussed.

RESULTS

Between January 2010 and January 2020, ten patients were diagnosed with nontraumatic spinal SAH (3 patients presented with isolated spinal SAH and 7 patients with concomitant spinal and posterior fossa SAH). Among those, 4 patients were found to have a spinal aneurysm as the cause of SAH. The aneurysms were located in the cervical regions in 3 patients (75%) and at the thoracic level in 1 patient. Two aneurysms (50%) involved the anterior spinal artery, and 2 aneurysms (50%) involved a radiculomedullary artery. One aneurysm was a flow-related aneurysm of the anterior spinal artery in the setting of bilateral vertebral artery occlusion and was treated by surgical clipping with good outcome. Three aneurysms were idiopathic pseudoaneurysms with a negative diagnostic evaluation for secondary causes. These pseudoaneurysms were treated conservatively; 2 patients did well and 1 patient passed away from severe intracranial vasospasm. Two aneurysms resolved on diagnostic angiogram, and 1 aneurysm was absent on initial angiogram and appeared on follow-up diagnostic imaging 3 months later.

CONCLUSIONS

Spinal aneurysms are rare neurovascular pathologies that should be considered in the setting of spinal and/or posterior fossa subarachnoid hemorrhage. Conservative treatment may be a potential safe alternative to interventional treatment. Before the initiation of surgical or endovascular treatment, spinal angiography should be repeated because of the potential for spontaneous resolution.

Spontaneous Spinal Subarachnoid Hemorrhage from a Ruptured Radiculopial Artery Aneurysm

BACKGROUND

Spontaneous spinal subarachnoid hemorrhage is an uncommon entity and is even rarer when secondary to intraspinal ruptured aneurysm. The clinical presentation of these cases usually includes back pain and headache; however, we report a unique case in which the patient became acutely paraplegic.

CASE DESCRIPTION

A 54-year-old woman initially presented with thunderclap headache and interscapular pain. There was no evidence of subarachnoid hemorrhage on noncontrast computed tomography of the head, but lumbar puncture revealed xanthochromia-positive cerebrospinal fluid. Subsequent computed tomography angiography identified a small right superior hypophyseal aneurysm. The patient then became acutely paraplegic during neurosurgical assessment in the emergency department. Urgent magnetic resonance imaging revealed extensive intradural hemorrhage in the cervicothoracic region, prompting emergent surgical decompression. At surgery, this hemorrhage was noted in a subarachnoid location, but no specific source was identified. Postoperative spinal digital subtraction angiography revealed an intraspinal aneurysm of the posterior spinal circulation involving the left T2 radiculopial artery, which was resected in a subsequent uneventful operation within the same hospital admission.

CONCLUSIONS

This unique clinical case highlights a rare cause of spontaneous acute paralysis and further demonstrates the safety of obliterating an intraspinal aneurysm via operative resection.

Intracranial subarachnoid hemorrhage resulting from non-cervical spinal arteriovenous lesions: Analysis of possible cause of bleeding and literature review

Subarachnoid hemorrhage (SAH) or intraventricle hemorrhage (IVH) with negative cerebral digital subtraction angiography (DSA) results, which are due to non-cervical spinal arteriovenous lesions, are uncommon. In this article we presented three cases from our hospital and nineteen cases from prior published literature and discussed clinical features, possible mechanisms underlying the hemorrhage and therapeutic strategies for managing this unusual entity. Our analysis revealed that headache was the most common initial symptom. Almost 60% of patients had symptoms related to the spinal cord at admission. Intramedullary arteriovenous malformations (AVM) were the most common type of malformation, and the thoracic segment was the most common location of the non-cervical spinal arteriovenous lesions. More than half of the patients had additional aneurysms. Surgery was chosen as the primary treatment modality in this series. Therefore, we speculate that thoracolumbar spinal arteriovenous lesions are an unusual cause of intracranial SAH with negative cerebral DSA results. If non-cervical spinal AVMs were associated with DSA-negative SAH, the pattern of hemorrhage could be manifested as the blood in supratentorial cisterns, the fourth ventricle or no copious blood around the foramen magnum as well (somewhat paradoxically), it depends on the timing of detection and image evaluation. The formation and the rupture of associated aneurysms were the most likely immediate cause of the intracranial SAH. If non-cervical spinal AVMs were not associated with DSA-negative SAH and all cases were genuine cases of 'SAH-of-unknown origin', the spinal AVM could be considered as incidental finding. Magnetic resonance imaging (MRI) of the complete spinal neuraxis is recommended to either exclude or identify a spinal lesion in these patients. Catheter-based spinal angiography remains the gold standard for the diagnosis of spinal vascular diseases. The decision regarding a therapeutic strategy is based on the angioarchitecture and on the type of spinal arteriovenous lesions.