Incidence and clinical characteristics of spinal arteriovenous shunts: hospital-based surveillance in Okayama, Japan

OBJECTIVE There have been no accurate surveillance data regarding the incidence rate of spinal arteriovenous shunts (SAVSs). Here, the authors investigate the epidemiology and clinical characteristics of SAVSs. METHODS The authors conducted multicenter hospital-based surveillance as an inventory survey at 8 core hospitals in Okayama Prefecture between April 1, 2009, and March 31, 2019. Consecutive patients who lived in Okayama and were diagnosed with SAVSs on angiographic studies were enrolled. The clinical characteristics and the incidence rates of each form of SAVS and the differences between SAVSs at different spinal levels were analyzed. RESULTS The authors identified a total of 45 patients with SAVSs, including 2 cases of spinal arteriovenous malformation, 5 cases of perimedullary arteriovenous fistula (AVF), 31 cases of spinal dural AVF (SDAVF), and 7 cases of spinal epidural AVF (SEAVF). The crude incidence rate was 0.234 per 100,000 person-years for all SAVSs including those at the craniocervical junction (CCJ) level. The incidence rate of SDAVF and SEAVF combined increased with advancing age in men only. In a comparative analysis between upper and lower spinal SDAVF/SEAVF, hemorrhage occurred in 7/14 cases (50%) at the CCJ/cervical level and in 0/24 cases (0%) at the thoracolumbar level (p = 0.0003). Venous congestion appeared in 1/14 cases (7%) at the CCJ/cervical level and in 23/24 cases (96%) at the thoracolumbar level (p < 0.0001). CONCLUSIONS The authors reported detailed incidence rates of SAVSs in Japan. There were some differences in clinical characteristics of SAVSs in the upper spinal levels and those in the lower spinal levels.

Spinal dural arteriovenous fistula masquerading as subdural hematoma

Background: This case highlights an angiographically occult spinal dural AVF presenting with a spinal subdural hematoma. While rare, it is important that clinicians be aware of this potential etiology of subdural hematomas before evacuation. Case Description: A 79-year-old female presented with acute lumbar pain, paraparesis, and a T10 sensory level loss. The MRI showed lower cord displacement due to curvilinear/triangular enhancement along the right side of the canal at the T12-L1 level. The lumbar MRA, craniospinal CTA, and multivessel spinal angiogram were unremarkable. A decompressive exploratory laminectomy revealed a subdural hematoma that contained blood products of different ages, and a large arterialized vein exiting near the right L1 nerve root sheath. The fistula was coagulated and sectioned. Postoperatively, the patient regained normal function. Conclusion: Symptomatic subdural thoracolumbar hemorrhages from SDAVF are very rare. Here, we report a patient with an acute paraparesis and T10 sensory level attributed to an SDAVF and subdural hematoma. Despite negative diagnostic studies, even including spinal angiography, the patient underwent surgical intervention and successful occlusion of the SDAVF.

P.050 Minimally invasive disconnection of spinal dural arteriovenous fistulas in a hybrid neurovascular operating room

Background: Hybrid neurovascular operating rooms offer significant advantages for vascular neurosurgery. In 2008, we installed North America’s first robotic intraoperative rotational 2D/3D angiography unit in a neurosurgery operating room. To date, 200 procedures have been performed. Methods: In selected cases of spinal dural arteriovenous fistula (dAVF)requiring surgical disconnection, intraoperative spinal angiographic roadmapping, angiographic image overlay onto the skin and surgically exposed spine, and laser cross-hair image guidance were utilized to accurately determine the location and trajectory of the draining vein. Results: In four cases of spinal dAVF, a minimally invasive approach was employed, via either single-level (N=2) or two-level (N=1) hemilaminectomy. Techniques used included: angiographic roadmap / image overlay and intraoperative fluoroscopic with laser light guidance. These provided sub-centimeter accuracy in localizing the path of the draining vein. Surgical incision lengths ranged between 4 to 5 cm, with the shortest incision measuring only 4.2 cm. Complete cure was obtained in all cases, with no untoward complications. Conclusions: Hybrid neurovascular operating room technology can facilitate the use of minimally invasive approaches to spinal dural AVF disconnection.

Spinal Dural Arteriovenous Fistula and Cecal Arteriovenous Malformation in a Boy

Concurrent spinal dural arteriovenous fistula (AVF) and cecal arteriovenous malformation (AVM) are very rare. A 6-year old boy presented with lower limb paresis after trauma. On imaging work-up spinal dural AVF was found. It was managed with endovascular glue embolization. After two years, the boy presented with severe anemia and occult gastrointestinal tract (GIT) bleed. Cecal AVM was diagnosed and managed with embolization.

Metachronous Multiplicity of Spinal Cord Arteriovenous Fistula and Spinal Dural AVF in a Patient with Hereditary Haemorrhagic Telangiectasia

HHT (Hereditary Haemorrhagic Telangiectasia or Rendu Osler Weber disease) is a known autosomal dominant dysplasia. The first clinical presentation of HHT in a child may be a cerebral or spinal AVM. We present the case of a young boy with HHT who had a previous spinal cord AVF treated by surgical obliteration and then presented with a spinal dural AVF nine months later. This patient had surgical obliteration of a spinal cord perimedullary AVF and subsequently developed a new spinal dural AVF at a different level. The diagnosis was made by spinal MR imaging and spinal angiography

Successful management of spinal dural arteriovenous fistulas undetected by arteriography

✓ Spinal dural arteriovenous fistulas (AVFs) frequently cause progressive myelopathy. When they are localized by imaging studies, surgery can be safely performed by simply interrupting the vein draining the fistula intradurally, and the results will be excellent and lasting. In some patients with clinical features of a spinal dural AVF and in whom magnetic resonance imaging and/or myelography findings are consistent with a diagnosis of a spinal dural AVF, however, spinal arteriography demonstrates no such results. The authors used a simple strategy based on knowledge of the epidemiology, pathophysiology, and anatomy of spinal dural AVFs to manage these cases successfully. In two patients, atherosclerotic occlusion was the primary cause for the failure of arteriography to visualize the dural AVF. The presence of an aortic aneurysm was an additional contributing factor preventing arteriographic visualization in one of these patients. In a third patient, massive obesity, and aortic atheroslerosis and tortuosity contributed to the absence of findings on three spinal arteriograms before surgical exploration lead to a more focused arteriographic examination that was successful.