PMC8422537_01
Sagittal T2-weighted image of the thoracolumbar spine shows abnormal hyperintense T2 signal representing spinal cord congestion extending from the conus medullaris to the level of T7 and intradural flow void from the level of L5 to T12 along anterior surface of the lower spinal cord.
SNI-12-405-g001.jpg
PMC8422537_01_SNI-12-405-g001.jpg
F1
T2 signal, representing spinal cord congestion, extending from the conus medullaris to the level of T7. There was abnormal tortuous and dilated flow void, running from the level of L5 to T12 along anterior surface of the spinal cord [Figure 1].
Anteroposterior views of the left L1 segmental artery angiography in (a) early, (b) middle, and (c) late phases demonstrate filling of the posterior spinal artery supplying the fistula (arrow), located at the level of L2 below the arterial basket of the conus medullaris forming from the bilateral posterior spinal arteries (arrowheads), with cranial drainage into perimedullary veins. (d) Anteroposterior view of flush aortography including lower aorta and bilateral iliac arteries reveals no more supply to the fistula.
SNI-12-405-g002.jpg
PMC8422537_01_SNI-12-405-g002.jpg
F2
Without selective catheterization into both internal iliac arteries, lower aorta and bilateral common iliac arteries angiography reveals no more supply to the fistula [Figure 2].
Intraoperative photograph during surgery on prone position after opening the dura. (a) Normal vessels on the filum terminale (black arrows). (b) The fistula is located on the left cauda equina nerve root (asterisk) supplied by the feeding artery (black arrowhead) with cranial drainage through the dilated radicular vein (white arrow) (c) another enlarged arterialized radicular vein (white arrowhead) running parallel to the cauda equina nerve root is observed with unknown origin.
SNI-12-405-g003.jpg
PMC8422537_01_SNI-12-405-g003.jpg
F3
Another enlarged arterialized radicular vein running parallel to another cauda equina nerve root is observed with unknown origin [Figure 3].
(a) Sagittal T2-weighted image of the thoracolumbar spine obtained 3 weeks after the operation reveals mild regression of spinal cord congestion and remaining of intradural flow void from L5 to L2. (b) Coronal magnetic resonance myelography of the lumbosacral spine demonstrates abnormal flow void running from the left sacral nerve root to the left-sided conus medullaris, probably representing a dilated radicular vein.
SNI-12-405-g004.jpg
PMC8422537_01_SNI-12-405-g004.jpg
F4
Another SDAVF was found at left S1 neural foramen supplied by the left lateral sacral artery (LSA) originating from the left internal iliac artery with venous drainage into perimedullary veins through the dilated and tortuous radicular vein, probably corresponding with another dilated arterialized radicular vein found during the operation [Figures 4 and 5].
(a-c) Sequential contrast-enhanced T1-weighted MRI coronal images show early enhanced tortuous and dilated intradural vessel, representing a radicular vein, draining cranially from the left sacral nerve root reaching the conus medullaris.
SNI-12-405-g005.jpg
PMC8422537_01_SNI-12-405-g005.jpg
F5
Another SDAVF was found at left S1 neural foramen supplied by the left lateral sacral artery (LSA) originating from the left internal iliac artery with venous drainage into perimedullary veins through the dilated and tortuous radicular vein, probably corresponding with another dilated arterialized radicular vein found during the operation [Figures 4 and 5].
Comparing between anteroposterior view of (a) preoperative the left L1 segmental artery angiography in late venous phase and (b) postoperative contrast-enhanced magnetic resonance angiography demonstrates the same venous drainage pattern (arrowheads), representing sharing the common medullary venous channel. The feeder from the left lateral sacral artery (arrows) is noted.
SNI-12-405-g006.jpg
PMC8422537_01_SNI-12-405-g006.jpg
F6
Comparing between preoperative the left L1 segmental artery angiography and postoperative contrast-enhanced MRA, there was the same venous drainage pattern, representing sharing the common medullary venous channel [Figure 6].