Yucatan micropigs have brain and spinal cord dimensions similar to humans and are useful for certain spinal cord injury (SCI) translational studies. Micropigs are readily trained in behavioral tasks, allowing consistent testing of locomotor loss and recovery. However, there has been little description of their motor and sensory pathway neurophysiology. We established methods to assess motor and sensory cortical evoked potentials in the anesthetized, uninjured state. We also evaluated epidurally evoked motor and sensory stimuli from the T6 and T9 levels, spanning the intended contusion injury epicenter. Response detection frequency, mean latency and amplitude values, and variability of evoked potentials were determined. Somatosensory evoked potentials were reliable and best detected during stimulation of peripheral nerve and epidural stimulation by referencing the lateral cortex to midline Fz. The most reliable hindlimb motor evoked potential (MEP) occurred in tibialis anterior. We found MEPs in forelimb muscles in response to thoracic epidural stimulation likely generated from propriospinal pathways. Cranially stimulated MEPs were easier to evoke in the upper limbs than in the hindlimbs. Autopsy studies revealed substantial variations in cortical morphology between animals. This electrophysiological study establishes that neurophysiological measures can be reliably obtained in micropigs in a time frame compatible with other experimental procedures, such as SCI and transplantation. It underscores the need to better understand the motor control pathways, including the corticospinal tract, to determine which therapeutics are suitable for testing in the pig model.

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Surgical site infection rates remain a common postoperative problem that continues to affect patients undergoing urologic surgery. Our study seeks to evaluate the difference in surgical site infection rates in patients undergoing open radical cystectomy when comparing the Bookwalter vs. the Alexis wound retractors. After institutional review board approval, we performed a retrospective chart review from February 2010 through August 2017 of patients undergoing open radical cystectomy with urinary diversion for bladder cancer. We then stratified the groups according to whether or not the surgery was performed with the Alexis or standard Bookwalter retractor. Baseline characteristics and operative outcomes were then compared between the two groups, with the main measure being incidence of surgical site infection as defined by the CDC. We evaluated those presenting with surgical site infections within or greater than 30 postoperatively. Of 237 patients who underwent radical cystectomy with either the Alexis or Bookwalter retractor, 168 patients were eligible to be included in our analysis. There was no statistical difference noted regarding surgical site infections (SSIs) between the two groups; however, the trend was in favor of the Alexis (3%) vs. the Bookwalter (11%) at less than 30 days surgery. The Alexis wound retractor likely poses an advantage in reducing the incidence in surgical site infections in patients undergoing radical cystectomy; however, multicenter studies with larger sample sizes are suggested for further elucidation.

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