Three-Dimensional Exoscope-Assisted Occlusion of a Foraminal Intradural Left L5-S1 Arteriovenous Fistula-Operative Video

Abstract

Spinal dural arteriovenous fistulas (dAVFs) are a rare type of spinal lesion that can cause severe clinical consequences.¹ Early and accurate diagnosis and treatment are crucial to avoid severe complications such as radicular pain, weakness, sensory deficits, and loss of bowel and bladder control.² Spinal dAVFs are commonly found in the lower thoracic or upper lumbar vertebrae. Spinal dAVFs are the most common spinal vascular malformations, of unknown cause, accounting for 70%-85 % of spinal shunts, with an annual incidence of 5-10 cases/1,000,000.³ Recently, they have been classified into extradural and intradural types, which may be further divided into dorsal and ventral lesions.^4,5 Spine magnetic resonance imaging (MRI) is the most performed imaging study for suspected dAVF diagnosis.¹ Catheter digital subtraction angiography (DSA) represents the gold-standard diagnosing technique. It provides critical information about the anatomy of the lesion, arterial inflow vessels, venous outflow, and endovascular treatment feasibility. DSA may also detect typical structures at risk during treatment.⁶ Surgical interruption of dAVF offers a complete cure, with low complication rates. Endovascular embolization might be safe and efficient, with high success rates, for selected vascular lesions.^7,8 This video presents a rare case of left L5-S1 dAVF, surgically occluded with the aid of a three-dimensional (3D) exoscope (Video 1). There is little evidence about the application of the 3D exoscope in spinal vascular microsurgery, whereas it has been widely used and described in cranial surgery and spinal, degenerative, tumor, and traumatic surgery.⁹ In our experience, the advantages of this operating tool are the sharp color vividness, which allows adequate discrimination of anatomic structures, the distinct depth perception, the educational value for operating room attendants, and the ergonomics for surgeons. Ergonomics for surgeons, especially, is optimally adapted to spinal surgery, given the contraposed placement of surgeons and the disposition of screens during the operating procedure.

Keywords: Dural arteriovenous fistula; Operative video; Spinal surgery; Spinal vascular malformation; Three-dimensional exoscope.