Compare 3 methods of nucleus pulposus (NP) volume measurement using the rabbit lumbar spines as a preclinical model to determine the effectiveness of prophylactic intervertebral disk fenestration in dogs.
Twelve 9-month-old, skeletally mature female entire New Zealand White rabbits weighing between 3.5 to 4.5 kg.
NP volume measurements of dissected rabbit lumber spines between L1 and L6 were made and compared using gross measurements, reconstructed MRI images, and water volumetry based on Archimedes’ principle. Water volumetry was used as the true gold standard volume measurement in this study.
The true volume (mean ± SD) of the nucleus pulposus NP as measured by water volumetry increased caudally from L1/L2 (16.26 ± 3.32 mm3) to L5/L6 (22.73 ± 6.09 mm3). Volume estimates made by MRI were significantly higher than those made using water volumetry at all sites (L1/L2 [P = .044], L2/L3 [P = .012], L3/L4 [P = .015], L4/L5 [P < .001], and L5/L6 [P < .001]). Gross measurements also significantly overestimated volume when compared to water volumetry at all sites; L1/L2 (P = .021), L2/L3 (P = .025), L3/L4 (P = .001), L4/L5 (P < .001), and L5/L6 (P < .001). MRI and gross volume estimates were significantly different at L4/L5 (P = .035) and L5/L6 (P = .030).
The findings of this preclinical model might be relevant to veterinary surgeons who perform prophylactic fenestration for which there is no reliable method to determine the amount of NP to be removed. Preclinical ex vivo and in vivo fenestration studies with pre- and postoperative NP volume assessment are required.
To determine the effect of a mobile UV-C disinfection device on the environmental bacterial bioburden in veterinary facilities.
40 swab samples of surfaces from the operating theaters of 3 veterinary hospitals and 1 necropsy laboratory.
Various surfaces were swabbed, and collected material was eluted from the swabs in PBSS. Then, an aliquot of the sample fluid was processed with a bacteria-specific rapid metabolic assay to quantify bacterial bioburden. Each site was then treated with UV-C light with an automated disinfection device for approximately 45 minutes. The same surfaces were swabbed following UV-C treatment, and bioburden was quantified. The bioburden at additional time points, including after a second UV-C treatment, was determined for the small animal operating theater.
All surfaces at all sites had a persistent viable bacterial population following manual cleaning. Disinfection with UV-C achieved a mean bioburden reduction of 94% (SD, 5.2%; range, 91% to 95%) for all surfaces, compared with manual disinfection alone. Repeated UV-C treatment of the small animal operating theater reduced mean bioburden by 99% (SD, 0.8%), including no detectable bacteria on 4 of 10 surfaces.
CONCLUSIONS AND CLINICAL RELEVANCE
Disinfection with UV-C light may be a beneficial adjunct method for terminal disinfection of veterinary operating theaters to reduce environmental bioburden.