Surgical management of spinal dural arteriovenous fistula - A single centre experience

Introduction: Spinal dural arteriovenous fistulas (sdAVF) are vascular malformations occurring in the spine which are commonly seen in elderly men in the sixth and seventh decade of life [1]. Patients initially present with nonspecific symptoms, eventually progressing to motor, sensory, and autonomic disturbances. Due to delayed presentation and non- specific symptoms, sdAVF are often undiagnosed, leading to delay in treatment. Aim: We report 4 cases of sdAVF who underwent microsurgical treatment. Methods: All the patients presented with insidious onset, gradually progressive bilateral lower limb weakness, paraesthesia, and urinary incontinence. MRI revealed subarachnoid flow voids and spinal cord T2 signal hyper-intensities in all 4 patients. Spinal angiogram showed fistula at T10,11 level in one patient, Ll level in two patients and at L5 in one patient. In these patients the artery supplying the AV fistula share a common pedicle with either artery of Adamkiewicz, Anterior spinal artery (ASA) or posterior spinal artery(PSA). Hence, the use of embolic agent in these patients to occlude the fistula carries a high risk of cord ischemia. In all these patients microsurgical procedure was carried out with successful outcomes. Results: All the 4 patients improved neurologically after surgery. Lower limb weakness and sensations improved early, but improvement of bladder function was delayed. Functional outcome was reassessed 6 months after the procedure using Modified Aminoff and Logue's scale, which was compared to pre-operative functional status of the individual. Conclusion: Timely intervention of sdAVF is challenging because of its nonspecific presentation. MRI offers a clue to the diagnosis while spinal angiography confirms the diagnosis and angio-architecture will decide the suitable mode of treatment. Though endovascular treatment is a viable option surgery is the gold standard [14].