Open AccessNew Insights from Immunohistochemistry for the Characterization of Epidural Scar Tissue
Author(s) -
Paulo Pereira,
António Avelino,
Pedro Monteiro,
Ruí Vaz,
Jose Manuel Castro-Lopes
Publication year - 2013
Publication title -
pain physician
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 99
eISSN - 2150-1149
pISSN - 1533-3159
DOI - 10.36076/ppj.2014/17/465
Subject(s) - medicine , biopsy , epidural space , pathology , lumbar , fibrosis , anatomy , surgery
Background: The association between epidural fibrosis and recurrent symptoms afterlumbar spine surgery remains a matter of debate in scientific literature and the underlyingpathophysiological mechanism has not been clearly elucidated.Objective: To investigate the presence of nerve fibers and the expression of osteopontinin epidural fibrous tissue after lumbar surgery in humans.Study Design: Laboratory study of human tissue samples.Methods: Twenty-four patients with persistent or recurrent low back and/or leg pain afterlumbar spine surgery, in whom no relevant findings were present on magnetic resonanceimaging (MRI) besides epidural scar tissue, were submitted to epiduroscopy. Biopsysamples of epidural scar tissue resting in the posterior epidural and periradicular spacewere obtained from 15 patients, using an endoscopic grasping forceps, in locations wherethe stimulation with the tip of a Fogarty consistently reproduced pain. Biopsy sampleswere processed for examination under optical and transmission electron microscopes andunder a fluorescence microscope after incubation in primary antibodies against beta3-tubulin or against osteopontin.Results: Optical and transmission electron microscopy revealed a homogeneous fibroustissue rich in collagen and lacking nerve fibers. No immunofluorescence was present inany of the samples immunoreacted against beta3-tubulin. In the samples immunoreactedagainst osteopontin, a punctate signal was detected around the collagen fibers.Limitations: Being a human study, there was no control group, so it is not possible todetermine the contribution of osteopontin in the formation of epidural fibrosis and itsrelation to the patients’ symptoms. Additional animal studies are needed to investigatethese issues.Conclusion: Rather than direct stimulation of nociceptors in the epidural scar tissue,other factors should relate epidural fibrosis and recurrent symptoms after lumbar spinesurgery. Osteopontin seems to play a role in the formation of epidural fibrosis.Key words: Osteopontin, failed back surgery syndrome, epidural fibrosis,immunofluorescence, beta3-tubulin, epiduroscopy, nerve fibers, lumbar surgery