Angiographic detection and characterization of "cryptic venous anomalies" associated with spinal cord cavernous malformations using flat-panel catheter angiotomography

BACKGROUND:: Spinal cord cavernous malformations (CMs) are associated with 2 types of angiographically occult "cryptic venous anomalies," which differ in location with respect to the spinal cord. The anatomic distinction between superficial and intramedullary is important in that the latter heighten the risks of CM resection. OBJECTIVE:: To report the observations of both types of cryptic venous anomalies documented during spinal digital subtraction angiography enhanced with flat-panel catheter angiotomography (FPCA). METHODS:: Spinal digital subtraction angiography enhanced with FPCA was performed in 2 adult patients with magnetic resonance imaging - documented intramedullary spinal cord CMs and prominent, nonspecific flow voids at the same levels. FPCA was obtained by selective injection of left T4 (case 1) and left T9 (case 2) with 5F Cobra 2 catheters (Terumo, Japan) during a 20-second rotational acquisition. Thirty milliliters of a 75% saline and 25% contrast solution (Omnipaque 300; GE) was administered. The rotational data set was reconstructed on a dedicated workstation (Leonardo; Siemens, Erlangen, Germany) through the use of regular and high-resolution matrixes, 0.4- and 0.1-mm voxel size, respectively. RESULTS:: Spinal digital subtraction angiography was unremarkable in both cases. In case 1, FPCA findings indicated an atypical network of prominent posterior perimedullary veins. In case 2, FPCA identified radially oriented channels forming a caput medusae pattern collecting into an enlarged intramedullary vein. CONCLUSION:: The unique ability of FPCA to image the spinal venous system enables the angiographic detection and characterization of abnormal spinal veins associated with CMs. Differentiating between the types of associated cryptic venous malformations may aid in surgical planning because the intramedullary type is associated with a higher risk of surgical complication.