title: Does Spinal Block Through Tattooed Skin Cause Histological Changes in Nervous Tissue and Meninges?: An Experimental Model in Rabbits.
abstract: OBJECTIVE
  Although there is no documented evidence that tattoo pigments can cause neurological complications, the implications of performing neuraxial anesthesia through tattooed skin are unknown. In this study, we aimed to assess whether spinal puncture performed through tattooed skin of rabbits determines changes over the spinal cord and meninges. In addition, we sought to evaluate the presence of ink fragments entrapped in spinal needles.
  
  
  METHODS
  Thirty-six young male adult rabbits, each weighing between 3400 and 3900 g and having a spine length between 38.5 and 39 cm, were divided by lot into 3 groups as follows: GI, spinal puncture through tattooed skin; GII, spinal puncture through tattooed skin and saline injection; and GIII, spinal puncture through skin free of tattoo and saline injection. After intravenous anesthesia with ketamine and xylazine, the subarachnoid space was punctured at S1-S2 under ultrasound guidance with a 22-gauge 2½ Quincke needle. Animals in GII and GIII received 5 μL/cm of spinal length (0.2 mL) of saline intrathecally. In GI, the needle tip was placed into the yellow ligament, and no solution was injected into the intrathecal space; after tattooed skin puncture, 1 mL of saline was injected through the needle over a histological slide to prepare a smear that was dyed by the Giemsa method to enable tissue identification if present. All animals remained in captivity for 21 days under medical observation and were killed by decapitation. The lumbosacral spinal cord portion was removed for histological analysis using hematoxylin-eosin stain.
  
  
  RESULTS
  None of the animals had impaired motor function or decreased nociception during the period of clinical observation. None of the animals from the control group (GIII) showed signs of injuries to meninges. In GII, however, 4 animals presented with signs of meningeal injury. The main histological changes observed were focal areas of perivascular lymphoplasmacyte infiltration in the pia mater and arachnoid. There was no signal of injury in neural tissue in any animal of both groups. Tissue coring containing ink pigments was noted in all GI smears from the spinal needles used to puncture the tattooed skin.
  
  
  CONCLUSIONS
  On the basis of the present results, intrathecal injection of saline through a needle inserted through tattooed skin is capable of producing histological changes over the meninges of rabbits. Ink fragments were entrapped inside the spinal needles, despite the presence of a stylet.
authors.affiliation: From Botucatu Medical School, University of São Paulo State, UNESP, Botucatu, São Paulo, Brazil.
authors.forename: Isabela Leite
authors.initials: IL
authors.lastname: Ferraz
authors.forename: Guilherme Antônio Moreira de
authors.initials: GA
authors.lastname: Barros
authors.forename: Patrícia Gomes
authors.initials: PG
authors.lastname: Ferreira Neto
authors.forename: Daneshivari
authors.initials: D
authors.lastname: Solanki
authors.forename: Mariângela Alencar
authors.initials: MA
authors.lastname: Marques
authors.forename: Vânia Maria de Vasconcelos
authors.initials: VM
authors.lastname: Machado
authors.forename: Lucas Wynne
authors.initials: LW
authors.lastname: Cabral
authors.forename: Rodrigo Moreira E
authors.initials: RM
authors.lastname: Lima
authors.forename: Pedro Thadeu Galvão
authors.initials: PT
authors.lastname: Vianna
authors.forename: Lais Helena Camacho
authors.initials: LH
authors.lastname: Navarro
authors.forename: Eliana Marisa
authors.initials: EM
authors.lastname: Ganen
mesh_terms: D000775:Anesthesia, Spinal / Q000009:adverse effects* / Q000295:instrumentation; D000818:Animals; D007278:Injections, Spinal / Q000009:adverse effects / Q000295:instrumentation; D008297:Male; D008578:Meninges / Q000473:pathology*; D023421:Models, Animal; D011817:Rabbits; D012867:Skin / Q000187:drug effects / Q000473:pathology*; D013116:Spinal Cord / Q000473:pathology*; D013653:Tattooing / Q000009:adverse effects*