A 33-year-old male presented with a 2-year history of pain in the lumbosacral spine with progressive lower-limb weakness, urinary frequency, and incontinence. Symptoms intensified after exercise and prolonged standing. Lumbar spine MRI demonstrated a tethered cord at the L3 level, a filum terminale lipoma, and edema in the spinal cord. It also showed tortuous veins on the posterior surface of the spinal cord (Figures ).\nThe neurological examination revealed bilateral hip-joint flexion weakness (grade 4 according to modified Medical Research Council system), plantar flexion weakness (grade 3 according to modified Medical Research Council system), and reduced sensation in the S2–S3 dermatomes. The Babinski and Rossolimo signs were present bilaterally. Based on the clinical and radiological signs, a SDAVF was suspected. A DSA confirmed the SDAVF at the S2-S3 level, in the dura supplied by lateral sacral arteries and branches from the internal iliac arteries. Tortuous draining veins were present on the posterior surface of the entire spinal cord and terminated intracranially (Figures ).\nThe patient underwent three endovascular embolizations, each with a different agent. First, embolization was performed with Onyx™ 18, administered in two microcatheters. This treatment resulted in an occlusion of the fistula. The patient significantly improved, but due to poor penetration of the draining vein, after a few weeks, the fistula recanalized and symptoms returned.\nA second embolization was performed 4 months later. The vascular access to the fistula was more complicated. A 25% Phil™ injection was feasible only through the small sacral branches of the left internal iliac artery. This procedure achieved a significant reduction of flow through the fistula. Eighteen months later embolization of the fistula was attempted with diluted glue. Despite good occlusion of the fistula observed in a DSA, the tortuous vessels remained visible in the follow-up MRI (Figures ). The symptoms persisted, and the patient was qualified for surgical treatment.\nThe goal of surgery was to occlude the draining vein and the arterial feeder and to reduce the lipoma. With a median incision, the sacral canal was opened on the right side. The dura was thick, and there were multiple vessels filled with embolic agents. There was one large, bright-red vessel extradurally and one intradurally at the S2-S3 level. A clip was placed upon the arterialized vein intradurally for a couple of minutes. After that, the vessel changed color and the tension decreased. Both intra- and extradural vessels were coagulated. Afterwards, the lipoma was visualized and partially removed. The dura was sutured in a watertight fashion, and the wound was closed in layers.\nThe postoperative course was uneventful, and a few days later, the patient was discharged. After 6 months, a follow up MRI showed the absence of tortuous vessels on the posterior surface of the spinal cord and a significant reduction in the myelopathic changes (Figure ). On follow-up, the patient considerably improved, with no incontinence, some urinary frequency and mild weakness (grade 4 according to modified Medical Research Council system).
A 58-year-old woman was referred for neurosurgical evaluation because of a 2-year history of rapid decline in bilateral motor functioning. Ten years earlier, she underwent an L4 and L5 laminectomy for cord detethering at an outside facility but had no meaningful improvement. Since then, she had experienced a gradual deterioration in her ambulation. Magnetic resonance imaging (MRI) demonstrated persistent evidence of cord tethering, with an L4/L5 lipomyelomeningocele extending to the sacral hiatus. Notably, prominent flow voids were also seen within the ventral subarachnoid space, with the most caudal draining vessel extending below the S2 sacral body. She had 3/5 strength in her left leg, 4/5 strength in her right, globally diminished sensation to light touch, and pin prick, as well as some bladder urgency. The patient did endorse some lower back pain but also has a history of chronic lower back pain. A diagnostic spinal angiogram showed evidence of a DAVF with arterial feeders from the bilateral lateral sacral arteries and right internal iliac artery with venous drainage to a dilated perimedullary vein. The patient underwent Onyx embolization of both feeding right and left lateral sacral arteries.\nThree months later, the patient exhibited marked improvement in her leg strength and sensation, improved 4-5/5 strength throughout her lower extremities, improved walking with assistance, and marked improvement in balance. At her 6-month follow-up, however, she reported stagnant functional capacity, with worsening of her left leg function that began after a ground-level fall. Physical examination revealed stable to improved right leg strength with subtle worsening of left leg strength (3-4/5). MRI revealed decreased flow voids compared with those seen on the prior study with no evidence of a new abnormality; however, one month later, evaluation revealed globally decreased lower extremity strength (3/5). Repeat spinal angiogram and lumbar MRI revealed new collateralized supply from the right internal iliac artery and lateral sacral branches. The DAVF now extended into the lipomyelomeningocele with dilated draining veins rostrally and spinal canal involvement.\nThe findings of redeveloping DAVF and the patient's clinical condition prompted us to recommend lipomyelomeningocele exploration/resection, DAVF ligation, and cord detethering. A standard midline approach was utilized, and a grossly abnormal fatty myelomeningocele was circumferentially dissected (). Intradural exploration demonstrated diffuse blood supply tracking through the lipomyelomeningocele with a large draining vein ventral to a tethered filum. The filum was sectioned, and the DAVF was clipped and ligated well into the arterialized vein. The remaining lipomyelomeningocele was mobilized and resected ().\nSix months after surgery, the patient regained full motor function of her proximal lower extremities with 5/5 strength throughout and 5/5 and 4/5 strength in her distal right and left lower extremities, respectively. MRI of the thoracic spine demonstrated marked improvement in the appearance of the spinal DAVF, with the tortuous vessels no longer evident. Follow-up spinal angiogram showed no evidence of residual DAVF or early draining vein ().