Can an inflammatory reaction in the meninges, caused by spinal puncture through tattooed skin, evolve into adhesive arachnoiditis? An experimental model in rabbits.

Background And Objectives: As the number of people with tattoos has been increasing, anesthesiologists are more and more faced with the decision to perform a neuraxial blockage through tattooed skin. In this study, we evaluated the possibility of puncture through tattooed skin determines acute inflammatory changes in the meninges and spinal cord and later evolve into adhesive arachnoiditis.

Method: Forty-two male rabbits were randomized into 3 groups of 14: G1, spinal puncture through non-tattooed skin and saline solution injection; G2, spinal puncture through tattooed skin and saline solution injection, captive for 30 days; G3, spinal puncture through tattooed skin and saline solution injection, captive for 360 days. The animals were anesthetized and ultrasound-guided spinal puncture was performed in the intervertebral spaces between S1 - S2. During the period of captivity, the animals were clinically assessed for sensitivity and motor function. After that, they were sacrificed and the lumbosacral portion of the spinal cord was excised for histological analysis.

Results: No histological changes were found on group 1. Eleven animals from group two presented with foci of perivascular lymphocytic inflammatory infiltrate in the pia mater and/or arachnoid. In Group 3, eight rabbits presented with inflammatory changes in the meninges, which were associated with thickening and/or adhesion of the pia mater and arachnoid in some cases and five rabbits presented only thickening of pia-mater.

Conclusions: Spinal puncture through tattooed skin of rabbits can trigger acute inflammatory changes in the meninges and after a prolonged period of observation evolve into adhesive arachnoiditis.