MATERIAL and METHODS: In a tertiary teaching institution, 25 adult cadavers were dissected by standard dissection procedure and spinal cord was removed with meninges. The dorsal aspect was further dissected out and layers of meninges were removed carefully to expose the extrinsic venous system in the dorsal region. The specimens that showed engorged veins were further studied for their extent, pattern, presence of radicular veins, their level and route of exit.

RESULTS: Five specimens showed variant dorsal venous pattern of the extrinsic system of veins in the thoracolumbar region. The main dorsal spinal vein was seen to be engorged, tortuous and more than 2mm with engorged radicular veins. Out of 8 engorged radicular veins observed, 6 exited through the dorsal nerve root foramen and 2 exited through a separate foramen.

CONCLUSION: The variant anatomy of intrathecal extrinsic venous system with engorgement of the thoracolumbar region veins might get injured during lumbar puncture procedure. The exit of radicular veins and the dorsal nerve root through the same foramen also makes the veins susceptible to post procedural spinal hematomas. Keywords : Spinal puncture, Hematoma, Spinal cord, Veins