The Role of Spectral Tissue Sensing During Lumbar Transforaminal Epidural Injection

Abstract

Spectral tissue sensing (STS) exploits the scattering and absorption of light by tissue. The main objective of the present study was to determine whether STS can discriminate between correct and incorrect placement of the needle tip during lumbar transforaminal epidural injection. This was a single-blind prospective observational study in 30 patients with lumbar radicular pain scheduled for lumbar transforaminal epidural injection. Spectral tissue sensing data from the needle tip were acquired along the needle trajectory at 4 predefined measurement points and compared with ultrasound, fluoroscopy, and digital subtraction angiography images. Spectral tissue sensing data contained the full spectra. The lipid and hemoglobin content at the different measurement points was also calculated, and partial least-squares discriminant analysis was used to estimate the sensitivity and specificity of STS. Spectral tissue sensing identified correct needle placement with a sensitivity of 57% and a specificity of 82%, and intraforaminal versus extraforaminal locations were identified with a sensitivity of 80% and a specificity of 71%.

Optical signature of nerve tissue—Exploratory ex vivo study comparing optical, histological, and molecular characteristics of different adipose and nerve tissues

“…Previous studies have shown that DRS can differentiate between adipose tissue, muscle, and blood . Our previous ex vivo DRS study demonstrated a sensitivity and specificity of 90% in discriminating whole nerve tissue compared to surrounding tissue .…”

“…Tissues that contain different amounts of these absorbers can be discriminated from each other . In an earlier in vivo study on optical detection of peripheral nerves, we concluded that differentiation between nerves in a fatty surrounding was difficult . In a more recent study in human cadavers, we found a sensitivity and specificity of 90% for discrimination of whole nerve tissue from surrounding tissues .…”

Eyes of the needle

“…45 In an earlier in vivo study on optical detection of peripheral nerves, we concluded that differentiation between nerves in a fatty surrounding was difficult. 41,42,46 In a more recent study in human cadavers, we found a sensitivity and specificity of 90% for discrimination of whole nerve tissue from surrounding tissues. 33 In both of these studies, the nerve was considered as one entity, and we did not account for the various structures that make up the nerve bundle.…”

“…Aspiration identifies the intravascular needle position in 25% to 47% of cases. 46 Injection of contrast fluid during live fluoroscopy detects the intravascular needle position in 60% to 71% of cases compared with digital subtraction angiography (DSA). [46][47][48] Currently, DSA is recommended to exclude intravascular needle placements during pain interventions.…”

“…46 Injection of contrast fluid during live fluoroscopy detects the intravascular needle position in 60% to 71% of cases compared with digital subtraction angiography (DSA). [46][47][48] Currently, DSA is recommended to exclude intravascular needle placements during pain interventions. 48,49 Despite the use of DSA, case reports of intravascular injection have been reported.…”