Shinji Yamamoto, Hideaki Kanaya and Phyo Kim
Spinal digital subtraction angiography (DSA) is indispensable for the precise diagnosis of spinal vascular lesions and the assessment of blood supply to the spinal cord. However, comprehensive spinal DSA covering multiple segments requires repetition of selective catheterization into small segmental arteries, which is time consuming, sometimes difficult, and hazardous. The authors investigated the usefulness of CT angiography with intraarterial contrast injection (IA-CTA) as a preliminary study preceding spinal DSA. With the advent of multidetector CT, it is feasible to obtain images of the spinal cord vasculature instantaneously overa number of segments.
A total of 56 patients with lesions involving the spinal vasculature underwent IA-CTA with 64- or 320-row detector CT in advance of comprehensive spinal DSA. Contrast material was injected via a pigtail catheter placed at the aorta in proximity to the segments of interest. Scanning was repeated twice to obtain arterial- and venous-phase images to differentiate between the arterial and venous components. The spinal arteries were identified by paging the various multiplanar reconstruction images and tracing the vessels from the aorta. Spinal DSA was subsequently performed by guiding selective catheterization to the feeding segments in reference to the IA-CTA findings. Visualization of the segmental arteries, normal spinal arteries, and abnormal vessels during IA-CTA was investigated and compared with that obtained during spinal DSA.
In all 56 patients, spinal IA-CTA successfully enabled visualization of the spinal vessels, including the radicular arteries and the anterior spinal artery. Below the aortic arch, all segmental arteries were identified clearly. The segmental arteries, radiculomedullary arteries, spinal arteries, and abnormal vessels were traced from the aorta, which would be the target of selective catheterization. In 3 (6.8%) patients, IA-CTA revealed severe aortic atherosclerosis and occlusion of some segmental arteries. The information obtained was useful for directing selective catheterization studies. The findings of IA-CTA corresponded well with those of spinal DSA.
IA-CTA is a useful adjunct to spinal DSA for surveying the vasculature surrounding the spinal cord and for orienting selective catheterization. IA-CTA can complement spinal DSA, curtail unnecessary segmental injections, and thus reduce procedural complications.
Keisuke Takai, Toshiki Endo, Takao Yasuhara, Toshitaka Seki, Kei Watanabe, Yuki Tanaka, Ryu Kurokawa, Hideaki Kanaya, Fumiaki Honda, Takashi Itabashi, Osamu Ishikawa, Hidetoshi Murata, Takahiro Tanaka, Yusuke Nishimura, Kaoru Eguchi, Toshihiro Takami, Yusuke Watanabe, Takeo Nishida, Masafumi Hiramatsu, Tatsuya Ohtonari, Satoshi Yamaguchi, Takafumi Mitsuhara, Seishi Matsui, Hisaaki Uchikado, Gohsuke Hattori, Nobutaka Horie, Hitoshi Yamahata and Makoto Taniguchi
Spinal arteriovenous shunts are rare vascular lesions and are classified into 4 types (types I–IV). Due to rapid advances in neuroimaging, spinal epidural AVFs (edAVFs), which are similar to type I spinal dural AVFs (dAVFs), have recently been increasingly reported. These 2 entities have several important differences that influence the treatment strategy selected. The purposes of the present study were to compare angiographic and clinical differences between edAVFs and dAVFs and to provide treatment strategies for edAVFs based on a multicenter cohort.
A total of 280 consecutive patients with thoracic and lumbosacral spinal dural arteriovenous fistulas (dAVFs) and edAVFs with intradural venous drainage were collected from 19 centers. After angiographic and clinical comparisons, the treatment failure rate by procedure, risk factors for treatment failure, and neurological outcomes were statistically analyzed in edAVF cases.
Final diagnoses after an angiographic review included 199 dAVFs and 81 edAVFs. At individual centers, 29 patients (36%) with edAVFs were misdiagnosed with dAVFs. Spinal edAVFs were commonly fed by multiple feeding arteries (54%) shunted into a single or multiple intradural vein(s) (91% and 9%) through a dilated epidural venous plexus. Preoperative modified Rankin Scale (mRS) and Aminoff-Logue gait and micturition grades were worse in patients with edAVFs than in those with dAVFs. Among the microsurgical (n = 42), endovascular (n = 36), and combined (n = 3) treatment groups of edAVFs, the treatment failure rate was significantly higher in the index endovascular treatment group (7.5%, 31%, and 0%, respectively). Endovascular treatment was found to be associated with significantly higher odds of initial treatment failure (OR 5.72, 95% CI 1.45–22.6). In edAVFs, the independent risk factor for treatment failure after microsurgery was the number of intradural draining veins (OR 17.9, 95% CI 1.56–207), while that for treatment failure after the endovascular treatment was the number of feeders (OR 4.11, 95% CI 1.23–13.8). Postoperatively, mRS score and Aminoff-Logue gait and micturition grades significantly improved in edAVFs with a median follow-up of 31 months.
Spinal epidural AVFs with intradural venous drainage are a distinct entity and may be classified as type V spinal vascular malformations. Based on the largest multicenter cohort, this study showed that primary microsurgery was superior to endovascular treatment for initial treatment success in patients with spinal edAVFs.