Risk factors for medullary infarction after endovascular trapping of vertebral artery dissecting aneurysms

Ruptured Vertebral Artery Dissection Treated with Endovascular Intervention

OBJECTIVE

A retrospective study of cases of endovascular treatment of dissection of the vertebral artery with subarachnoid hemorrhage was conducted.

MATERIAL AND METHODS

Data were 11 cases of vertebral artery dissecting aneurysm (VADA) among 291 consecutive subarachnoid hemorrhage patients who underwent clipping or endovascular treatment at Ota Memorial Hospital. Classified into 4 patterns based on the location of the dissection and posterior inferior cerebellar artery (PICA): pre-PICA, post-PICA, involved PICA, and non-PICA. And one of the cases had bilateral vertebral artery dissection, and computational fluid dynamics analysis was included in the study.

RESULTS

Ruptured VADA occurred in 11 of the 291 patients (3.8%). Endovascular treatment was performed in 8 of these 11 patients. Postoperative diffusion-weighted imaging detected no high-intensity lesions and no postoperative ischemic complications or rebleeding occurred in any patient. In a case of bilateral VADA, computational fluid dynamics analysis of very low or high wall shear stress at the dissection, low aneurysm formation indicator, and high oscillatory shear index may be considered rupture factors.

CONCLUSIONS

Treatment strategies for each branching pattern of PICA can prevent rupture and avoid ischemic complications. And prediction of the rupture side is important in patients with bilateral dissection to consider the appropriate treatment and timing.

Spontaneous intracranial vertebral artery dissections presenting with subarachnoid hemorrhage

BACKGROUND

Vertebral artery dissection (VAD) is an infrequent source of subarachnoid hemorrhage (SAH), with a high mortality rate, primarily due to the risk of rebleeding both before and after medical intervention. This paper provides a comprehensive analysis of the anatomy, pathophysiology, clinical presentation, treatment strategies, and outcomes of intracranial vertebral artery dissections that result in subarachnoid hemorrhage.

METHODS

Comprehensive five-year literature review (2018-2022) and a retrospective analysis of patient records from our institution between 2016 and 2022. We included studies with a minimum of 5 patients.

RESULTS

The study incorporated ten series from the literature and 22 cases from CHUM. Key anatomical factors increasing the risk of VAD include the vertebral artery's origin from the aortic arch, asymmetry of the vertebral artery, and its tortuosity. Patients may display specific collagen and genetic abnormalities. The occurrence of VAD appears to be more prevalent in men. Those with a ruptured intracranial VAD typically show prodromal symptoms and present with severe SAH. Rebleeding within the first 24 h is frequent. While standard imaging methods are usually adequate for VAD diagnosis, they may not provide detailed information about the perforator anatomy. Treatment approaches include both deconstructive and reconstructive methods.

CONCLUSION

Ruptured VAD is a critical, life-threatening condition. Many patients have a poor neurological status at presentation, and rebleeding prior to treatment is a significant concern. Deconstructive techniques are most effective in preventing rebleeding, whereas the efficacy of reconstructive techniques needs more investigation.

Endovascular Treatment for Intracranial Artery Dissections in Posterior Circulation

Intracranial artery dissections (IADs), although uncommon, are an important cause of cerebral infarction and subarachnoid hemorrhage (SAH). Some IADs can heal spontaneously after reconstitution of the vessel lumen with excellent prognosis. Meanwhile, others can progress to stroke that requires treatment. The incidence of IAD in the posterior circulation is higher than that in the anterior circulation. Anterior circulation dissections are more likely to develop into ischemia and posterior circulation lesions into hemorrhage. The mortality rate after IAD among patients with SAH is 19%-83%. Further, the mortality rate of IAD without SAH is 0%-3%. Patients with SAH commonly undergo surgery or receive neuroendovascular treatment (EVT) to prevent rebleeding. However, the treatment of IADs is empirical in the absence of data from randomized controlled trials. Recently, EVT has emerged and is considered for IADs because of its less invasiveness and perceived low rates of procedure-related morbidity with good efficacy. EVT strategies can be classified into deconstructive (involving sacrifice of the parent artery) and reconstructive (preserving blood flow via the parent vessel) techniques. In particular, the number of reports on reconstructive techniques is increasing. However, a reconstructive technique for ruptured IADs has not yet been established. This review aimed to provide an overview of IADs in the posterior circulation managed with EVT by performing a literature search.

Flow diverters in the treatment of unruptured vertebral artery dissecting aneurysm: A single-center experience

Objective

To evaluate the efficacy and safety of flow diverters (FD) in the treatment of vertebral artery dissecting aneurysm (VADA).

Methods

A total of 16 patients with 17 unruptured VADAs treated with FD from January 2017 to May 2021 were included. Data of clinical outcomes and radiographic examination were collected and assessed by the modified Rankin Scale (mRS) and O'Kelly-Marotta (OKM) grading scale.

Results

All patients were treated with a single FD. No perioperative complications occurred. The mean age was 55.1 years old. The mean size of the aneurysm was 10.4 mm. All patients had a favorable occlusion (OKM D + C3) result and the complete occlusion rate in the 6th month was 66.7% (OKM D). The mean clinical follow-up time was 7.8 months, and all patients had a good clinical outcome (mRS = 0). No procedure-related complication occurred at the last follow-up time.

Conclusion

FD is an effective and safe tool for treating unruptured VADA. Long-term prospective studies with a large sample are still needed to confirm these findings in the future.

Severe Complications After Endovascular Trapping of Vertebral Artery Dissecting Aneurysm: Simultaneous Occurrence of Medullary and Cervical Spinal Cord Infarction

Endovascular trapping of vertebral artery dissecting aneurysm (VADA) can lead to ischemic complications, including medullary infarction due to obstruction of perforating arteries, and cervical spinal cord infarction caused by ischemia of spinal arteries branching from the affected vertebral artery (VA). This report describes a rare case of concomitant medullary and spinal cord infarction following internal trapping of ruptured VADA.

A 47-year-old male presented with severe subarachnoid hemorrhage and neurological pulmonary edema, and a vertebral angiogram demonstrated VADA. A small-sized posterior inferior cerebellar artery (PICA) was found proximal to the affected vessel. The anterior spinal artery (ASA) branched distal to a dilated portion. Perforating arteries were insufficiently visualized due to image quality. Internal trapping was performed, and complete occlusion of VADA was achieved, preserving the origin of ASA. Postoperative magnetic resonance imaging (MRI) revealed ischemic lesions in the lateral medulla oblongata and upper cervical spinal cord. The patient presented with severe neurological symptoms, including lower cranial neuropathy due to medulla infarction, respiratory dysfunction, and tetraparesis due to cervical spinal cord infarction. The modified Rankin scale at three months was grade 5.

Various factors, including perforating artery ischemia, unstable general condition, and insufficient antithrombotic therapy, were considered the cause. Therefore, evaluating the tiny perforating and spinal arteries branching from the VA should be especially considered to avoid these complications. Furthermore, advances in angiographic apparatus and workstations should provide a high-resolution radiological image and adequate treatment strategy.