Neurochirurgie最新文献

Background

Genetic polymorphism of KIAA1217 has been reported to be associated with lumbar disc herniation (LDH) in different populations such as Japanese population and Finnish population. This study aimed to explore whether the genetic polymorphism of KIAA1217 is functionally associated with LDH in Chinese population.

Methods

SNP rs16924573 of KIAA1217 was genotyped in 1272 patients and 1248 healthy controls. The mRNA expression of KIAA1217 in the intervertebral disc was analyzed for 84 patients and 32 controls. The differences of genotype and allele distributions between LDH patients and healthy controls were evaluated using the Chi-square test. One-way ANOVA test was used to compare the relationship between genotypes and tissue expression of KIAA1217.

Results

Patients were found to have significantly higher frequency of genotype GG of rs16924573 than the controls (64.2% vs. 52.8%, p < 0.001). The frequency of allele G was remarkably higher in the patients than in the controls (79.8% vs. 73.2%, p < 0.001), with an OR of 1.45 (95% confidential interval = 1.27–1.66). Compared with the controls, LDH patients were observed to have significantly decreased expression of KIAA1217. Patients with genotype GG had remarkably lower mRNA expression of KIAA1217 than those with genotype AG or AA (p = 0.01).

Conclusions

SNP rs16924573 of KIAA1217 could be functionally associated with LDH in the Chinese population. More in vivo and vitro experiments need to be carried out to further clarify the regulatory mechanism of functional variants in KIAA1217.

Background

Dural arteriovenous fistulas of the marginal sinus (DAVFms) are uncommon and complex, with varied symptoms. Their complexity is heightened by the region's dense anastomotic network, posing risks for endovascular treatment. Surgical intervention can be effective, but this depends on thorough pre-operative understanding and optimal intra-operative visualization of the fistula.

Objective

To review the relevant anatomy, presentation patterns of DAVFms, and provide insights for surgical treatment.

Methods

Recent literature on DAVFms was reviewed, and three surgical cases are discussed to highlight treatment principles.

Results

The symptoms of a DAVFms vary depending on its venous drainage pattern. Drainage may be either ascending towards the cranial compartment or descending towards the spinal canal. Patients suffering from DAVFms may experience hemorrhage, particularly when venous drainage is directed upwards. Congestive symptoms of the spinal cord or brainstem can occur in cases of downward venous drainage. Compared to the endovascular approach, open surgery has a higher success rate in obliterating the fistula and yields better outcomes in cases of perimedullary venous drainage. Achieving surgical success necessitates thorough preoperative evaluation and adequate surgical exposure. Brainstem hyperintensity observed on T2-weighted MRI scans is linked to a poorer prognosis for recovery.

Conclusion

Treating complex DAVFms often requires surgery, as endovascular methods may not be feasible. Successful surgery hinges on a precise understanding of the fistula's venous architecture and its spatial relationships, assessed using digital substraction angiography (DSA), angio-MRI, and angio-CT. Optimal intraoperative exposure is crucial for effective surgery.

Intrinsic pathologies of the vertebral arteries, such as atherosclerosis, dissection, fibromuscular dysplasia, radionecrosis and vasculitis, are important causes of vertebrobasilar insufficiency and cerebrovascular events. This review focuses on non-aneurysmal intrinsic stenosing and occlusive pathologies, covering their epidemiology, diagnosis, and treatment options. It also provides a detailed summary of key clinical presentations and syndromes, including an in-depth examination of lateral medullary syndrome, historically known as Wallenberg's syndrome, which is arguably the most emblematic condition resulting from vertebral artery involvement and is depicted in an illustrative cartoon.

Background

The vertebral arteries (VA) play a critical role by supplying nearly one-third of the brain’s blood flow, predominantly contributing to the posterior circulation. These arteries may need to be exposed in a various cranial and cervical procedures and offers access to investigate or treat vascular lesions by endovascular means related to the posterior circulation. Given its complex anatomy, which is subject to numerous variations, and its role in supplying vital brain regions, a thorough understanding of the VA’s anatomy is paramount for any related procedure.

Objective

To provide a comprehensive overview of vertebral artery anatomy and its relevance in contemporary clinical practice.

Methods

Dissection of the entire vertebral artery length using cadaveric specimen, combined with a comprehensive literature review.

Results

The vertebral artery can be subdivided into four segments. Each of these segments has its own unique topographic anatomy with its variations, anastomoses, and significance in surgery.

Conclusion

As surgical and endovascular techniques continue to evolve with technological improvements, we are now more equipped than ever to manage complex lesions involving the VA. However, with its increasingly complexity comes the necessity for a deeper and more comprehensive understanding of the VA. Possessing the detailed knowledge of the VA is vital for the successful execution of any procedure involving it.

The vertebral arteries (VAs) constitute most of the arterial supply to the posterior cerebral vascular circulation. They have anatomical specificities and may have variants that are critical for neurointerventionists to recognize in order to design open or endovascular surgical treatment. This review addresses each segment of the VA including its origin and discusses the branches and relevant anatomical features for neurointerventions.

Background

Rotational vertebral artery syndrome, also referred to as Bow Hunter’s syndrome (BHS), manifests when the vertebral artery (VA) is compressed following head rotation. This compression is often caused by an osteophyte and may lead to symptoms of a posterior stroke. This systematic review aims to shed light on the current management strategies for BHS resulting from osteophytes. Additionally, we present two illustrative cases where the VA compression by an osteophyte was effectively resolved by complete resection of the problematic bone spur.

Methods

A literature search was conducted across Embase, PubMed and Medline in September 2023. Keywords related to vertebral artery [MESH], vertebrobasilar insufficiency [MESH] and osteophyte [MESH] were the focus of this review. Risk of bias in retained studies was assessed using the Joanna Briggs Institute Critical Appraisal tools for Qualitative Research. A narrative synthesis of our findings is presented.

Results

A total of 30 studies were included in this review. Vertigo was the most reported symptom by patients (n = 16). On imaging, the VA was often compressed at C4−5 (n = 10) and C5−6 (n = 10) with no evident side predominance observed. Anterior cervical discectomy and fusion (ACDF, n = 13) followed by anterior decompression without fusion (n = 8) were the most performed surgical procedures to manage BHS.

Conclusion

Surgical decompression of the VA is a safe and effective intervention for patients experiencing symptomatic osteophytic compression during head rotation. This procedure restores normal vascular function and reduces the risk of ischemic events. This review highlights the importance of timely diagnosis and intervention in such cases.

Background and Objectives

The pathophysiology of spontaneous vertebral artery dissecting aneurysms (SVADA) is poorly understood. Our goal is to investigate the hemodynamic factors contributing to their formation using computational fluid dynamics (CFD) and deep learning algorithms.

Methods

We have developed software that can use patient imagery as input to recreate the vertebrobasilar arterial system, both with and without SVADA, which we used in a series of three patients. To obtain the kinematic blood flow data before and after the aneurysm forms, we utilized numerical methods to solve the complex Navier-Stokes partial differential equations. This was accomplished through the application of a finite volume solver (OpenFoam/Helyx OS). Additionally, we trained a neural ordinary differential equation (NODE) to learn and replicate the dynamical streamlines obtained from the computational fluid dynamics (CFD) simulations.

Results

In all three cases, we observed that the equilibrium of blood pressure distributions across the VAs, at a specific vertical level, accurately predicted the future SVADA location. In the two cases where there was a dominant VA, the dissection occurred on the dominant artery where blood pressure was lower compared to the contralateral side. The SVADA sac was characterized by reduced wall shear stress (WSS) and decreased velocity magnitude related to increased turbulence. The presence of a high WSS gradient at the boundary of the SVADA may explain its extension. Streamlines generated by CFD were learned with a neural ordinary differential equation (NODE) capable of capturing the system’s dynamics to output meaningful predictions of the flow vector field upon aneurysm formation.

Conclusion

In our series, asymmetry in the vertebrobasilar blood pressure distributions at and proximal to the site of the future SVADA accurately predicted its location in all patients. Deep learning algorithms can be trained to model blood flow patterns within biological systems, offering an alternative to the computationally intensive CFD. This technology has the potential to find practical applications in clinical settings.

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.

The vertebral arteries represent in the adult the main blood supply of the posterior cranial fossa, even if they appear relatively late during the embryological life.

We reviewed all the most important steps of the vertebral artery’s embryological development and the most common variants that can occur in the adult.

The aim of this review is to summarize the main events of the development of this artery and to give an embryological explication for the most common variants of this artery.