Background: One of the most important conditions where there is loss of normal bladder function is spinal cord injury
(SCI). Currently, evaluation of bladder function is limited to periodic invasive urodynamic testing (UDS). The purpose
of this study was to assess the feasibility and usefulness of near-infrared spectroscopy (NIRS) in monitoring bladder
function in patients with SCI during bladder filling and emptying and to investigate the correlations of NIRS measures
with simultaneous UDS parameters. NIRS is a non-invasive optical method to study tissue oxygenation, hemodynamics
and function by monitoring changes in the chromophore concentrations of oxygenated (O2Hb), deoxygenated (HHb) and
total hemoglobin (tHb).
Methods: 10 adult paraplegic patients with neurogenic bladder dysfunction who were referred for regular urodynamic
evaluation were recruited. Changes in O2Hb, HHb and tHb, and tissue saturation index (TSI%) in the detrusor were
monitored and recorded by a wireless NIRS system during the urodynamic evaluation. Time points of urgency and
urinary leakage were marked and patterns of change in NIRS parameters were compared to standard urodynamic
Results: Strong consistency between changes in NIRS-derived tHb and changes in intravesical pressure were observed
during filling across the subjects. During bladder filling a gradual increase in O2Hb and tHb with minimal changes in
HHb was observed. Interestingly, a drop in TSI% was detected seconds before strong urgency and urinary leakage.
Conclusions: Our preliminary data suggest a relationship between noninvasive NIRS measures and UDS parameters
during bladder filling in SCI patients.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.