Clinical utility of multidetector row computed tomography for diagnosing spinal dural arteriovenous fistulas undiagnosed by magnetic resonance imaging

Spinal Dorsal Intradural Arteriovenous Fistulas: Natural History, Imaging, and Management

In this review, we describe the pathophysiology, diagnosis, and treatment of spinal dorsal intradural arteriovenous fistulas (DI-AVFs), focusing on novel research areas. DI-AVFs compose the most common subgroup of spinal arteriovenous lesions and most commonly involve the thoracic spine, followed by lumbar and sacral segments. The pathogenesis underlying DI-AVFs is an area of emerging understanding, thought to be attributable to venous congestion and hypertension that precipitate ascending myelopathy. Patients with DI-AVFs typically present with motor, sensory, or urinary dysfunction, although a wide swath of other less common symptoms has been reported. DI-AVFs can be subdivided by spinal region, which in turn is associated with 4 distinct clinical phenotypes: craniocervical junction (CCJ), subaxial cervical, thoracic, and lumbosacral. Patients with CCJ and lumbosacral DI-AVFs have particularly interesting presentations and treatment considerations. High-value diagnostic findings on MRI include flow voids, missing-piece sign, and T2-weighted intramedullary hyperintensity. However, digital subtraction angiography is the gold standard for diagnosis and localization of DI-AVFs and for definitive treatment planning. Surgical disconnection of DI-AVFs is almost universally curative and frontline treatment, especially for CCJ and lumbosacral DI-AVFs. Endovascular techniques evolve in promising ways, such as improved visualization, distal access, and liquid embolic techniques. The pathophysiology of DI-AVFs is better understood using newly identified radiologic diagnostic markers. Despite new techniques and devices introduced in the endovascular field, surgery remains the gold-standard treatment for DI-AVFs.

ACR Appropriateness Criteria® Myelopathy: 2021 Update

Myelopathy is a clinical diagnosis with localization of the neurological findings to the spinal cord, rather than the brain or the peripheral nervous system, and then to a particular segment of the spinal cord. Myelopathy can be the result of primary intrinsic disorders of the spinal cord or from secondary conditions, which result in extrinsic compression of the spinal cord. While the causes of myelopathy may be multiple, the acuity of presentation and symptom onset frame a practical approach to the differential diagnosis. Imaging plays a crucial role in the evaluation of myelopathy with MRI the preferred modality. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The current status and recent advances in high-resolution imaging of spinal vascular malformations

The management of spinal vascular malformations (SVM) has improved over the last four decades with the evolution of imaging, anesthesia, microsurgery, and endovascular techniques. Commonly used high-resolution imaging techniques include CT angiography, magnetic resonance angiography, and digital subtraction angiography. We review the advances that have been made in these imaging modalities and discuss their present role for imaging SVM, with the goal of assisting neurosurgeons in making judicious use of current imaging techniques to develop the most effective management strategies for these complex lesions.

Clinical outcome of treatments for spinal dural arteriovenous fistulas: results of multivariate analysis and review of the literature

STUDY DESIGN

This study was a case series study using a prospective single-institute database for the treatment of spinal dural arteriovenous fistulas (SDAVFs).

OBJECTIVE

To evaluate clinical factors that influence the neurological outcomes of treatment for SDAVFs, which were obtained from the analysis of 21 patients treated in our institution, and to provide management recommendations based on the review of former major clinical studies including our own reported over the past 2 decades.

SUMMARY OF BACKGROUND DATA

Since 1977, when Kendall and Logue described the etiology of SDAVFs as hyperpressure of intrathecal veins due to an abnormal shunting from the arteries, treatment strategies have improved dramatically along with developments in neuroimaging, endovascular techniques and materials, and microsurgery based on the underlying pathophysiological process. However, therapeutic guidelines remain controversial.

METHODS

Patients treated for SDAVFs from 2000 to 2008 were eligible. Age, sex, level of shunting, initial symptom, duration of symptom, the treatment method, and clinical symptoms before and 6 months after treatment were investigated.

RESULTS

There were a total of 30 patients (18 male and 12 female), with a mean age of 59 years; 21 of them underwent treatment for the first time. We conducted a univariate analysis using a logistic regression model, on age, sex, the level of SDAVFs, duration of symptoms, symptom (sensory or paralysis), and gait function and micturition before treatment, and the intervention method were set as variables to investigate the risk factors for motor deficit 6 months after the treatment. Only gait function before treatment was correlated with the motor deficit 6 months after treatment (odds ratio = 10.0; 95% confidence interval = 1.28-78.11, P = 0.03).From these results, intervention at an early stage would be the key to a preferable outcome of the treatment for SDAVFs.

CONCLUSION

The clinical status before treatment significantly influenced the clinical outcome after the treatment.