Objectives To examine the utility of standardised volumetric spinal cord measurement as an indicator of successful disconnection of a Type 1 spinal dural arteriovenous fistula.

Design Retrospective analysis at a tertiary neuroscience centre.

Subjects Patients with symptomatic Type 1 spinal dAVFs presenting to the senior author and neurovascular MDT (June 2009 – December 2017). Inclusion based on availability of appropriate cross-sectional imaging. DAVFs arising below T12 excluded: 18 patients with a total 19 dAVFs identified.

Methods Type 1 fistulation demonstrated on TRICKS MR angiography and spinal catheter angiography. Sagittal volumes evaluated using Horos (Purview, Annapolis, USA) and wireframe models created. Measurement arbitrarily standardised at ±2 levels from the origin of the fistulous draining vein. Pre- and post-operative clinical outcomes assessed using the Aminoff-Logue Scale. Wilcoxon test employed for between-group comparisons and Spearman’s rank test for clinico-radiological correlation (Prism 7, GraphPad Software, Inc. California).

Results Cord volumes reduced by a mean of 0.854 cm3 (p=0.0181; 95% CI=−1.55,–0.16; SD=1.44). Volume change was not related to gait (r=0.037, p=0.8812, 95% CI=−0.44, 0.49) or micturition scores (r=−0.24, p=0.3165, 95% CI=−0.64, 0.25).

Conclusions Surgical disconnection of type 1 dAVF resulted in a reduction in spinal cord volume. This was not predictive of change in clinical indices in this small series but perhaps merits investigation of this as a surrogate marker in a larger series.