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Purpose: Buccal mucosal grafts have a well-established role in urology regarding the management of ureteric stricture disease. Despite its established use as a graft material there is a lack of data on the mechanical properties of buccal mucosa. We aim to compare the passive mechanical properties of porcine buccal mucosa with the ureter. Materials and methods: Buccal mucosa (n = 20) and ureteric specimens (n = 21) were harvested from 19 domestic pigs at the time of euthanasia. Mechanical testing was performed using a uniaxial tensometer to generate stress-strain curves. From these curves, ultimate tensile strength and elastic modulus were calculated. Data was analysed, and one-way ANOVA testing was used to assess for significance variation in mechanical response due to direction of testing, and between tissue types. Results and conclusions: Porcine ureteric specimens displayed mechanical anisotropy, with a significant difference in the elastic modulus depending on the direction of testing (p = 0.005), and a higher mean ultimate tensile strength in the longitudinal (498.09 kPa) compared to the transverse (263.99 kPa) direction (p = 0.0005). Buccal mucosa was isotropic with no significant difference in elastic modulus or ultimate tensile strength according to direction of testing. Comparison of tissue types showed a significantly greater mean ultimate tensile strength in the longitudinal direction (p = 0.002) in ureter compared to buccal mucosa. We present the first comparison of the mechanical properties of buccal mucosa with ureter, and demonstrate significant variation in elastic modulus and ultimate tensile strength between the tissue types. These findings have important clinical implications for physiological function and in the design of alternative approaches for reconstruction in buccal mucosa grafted ureters. [ABSTRACT FROM AUTHOR]

Purpose: There are no prospective data describing the incidence and spectrum of long-term complications associated with traumatic urethral catheterisation (UC). We prospectively monitored the long-term clinical outcomes and complications of patients with traumatic UC injuries. Methods: A prospective study at two tertiary university hospitals was performed to record all referrals for iatrogenic urethral injuries caused by UC. Long-term follow-up was prospectively maintained by regular outpatient department visits and by monitoring all urological interventions and their outcomes from urinary catheter-related injuries. Results: The incidence of traumatic UC was 13.4 per 1000 catheters inserted in male patients and 37 iatrogenic urethral injuries were recorded. The mean age was 74 ± 12 years and the mean length of follow-up was 37 ± 3.7 months. Urethral injuries were caused by inflating the catheter anchoring balloon in the urethra (n = 26) or by creating a false passage with the catheter tip (n = 11). In total, 29 patients (78%) developed urethral stricture disease during their follow-up; of which 11 have required at least one urethral dilation and two have required one urethrotomy. Three patients required long-term indwelling suprapubic catheter placement and seven patients opted for a long-term indwelling urethral catheter. There were eight patient mortalities; one of which was due to severe urosepsis resulting from catheter balloon inflation in the urethra. Conclusion: Catheter-related injuries are associated with significant long-term complications in this vulnerable patient cohort. In future, such injuries may be preventable if the safety profile of the urinary catheter is modified. [ABSTRACT FROM AUTHOR]

Ammonium urate nephrolithiasis frequently develops in common bottlenose dolphins (Tursiops truncatus) managed under human care but is rare in free-ranging common bottlenose dolphins. In other species, the dietary cation-anion difference (DCAD) can affect ammonium urate urolith formation by increasing proton excretion as ammonium ions. Therefore, differences in diet between the 2 dolphin populations could affect urolith formation, but the DCAD of most species consumed by free-ranging and managed dolphins is unknown. To compare the nutrient composition of diets consumed by free-ranging and managed bottlenose dolphins, samples (n = 5) of the 8 species of fish commonly consumed by free-ranging bottlenose dolphins in Sarasota Bay, FL, and the 7 species of fish and squid commonly fed to managed bottlenose dolphins were analyzed for nutrient content. Metabolizable energy was calculated using Atwater factors; the DCAD was calculated using 4 equations commonly used in people and animals that use different absorption coefficients. The nutrient composition of individual species was used to predict the DCAD of 2 model diets typically fed to managed common bottlenose dolphins and a model diet typically consumed by common bottlenose dolphins in Sarasota Bay. To mimic differences in postmortem handling of fish for the 2 populations of bottlenose dolphins, "free-ranging" samples were immediately frozen at -80°C and minimally thawed before analysis, whereas "managed" samples were frozen for 6 to 9 mo at -18°C and completely thawed. "Free- ranging" species contained more Ca and P and less Na and Cl than "managed" fish and squid species. As a consequence, the DCAD of both model managed dolphin diets obtained using 3 of the 4 equations was much more negative than the DCAD of the model free-ranging bottlenose dolphin diet (P < 0.05). The results imply that managed bottlenose dolphins must excrete more protons in urine than free-ranging bottlenose dolphins, which will promote nephrolith formation. The nutrient composition of the free-ranging bottlenose dolphin diet, determined for the first time here, can be used as a guide for feeding managed bottlenose dolphins, but research in vivo is warranted to determine whether adding more cations to the diet will prevent urolith formation in managed dolphins. [ABSTRACT FROM AUTHOR]