Experimental studies with total and static urethral pressures in canine urethra and their clinical significance

Abstract

AbstractCanine experiments were conducted in order to determine potential sources of error in measurement of total and static urethral pressures during urodynamic studies. Transmural urethral cannulas were inserted at various urethral sites, downstream and upstream of an elastic constriction, and attempts were made to study 1) the effect of increasing rates of urethral perfusion, 2) the differences in static and total urethral pressures at a urethral site, and 3) the differences between the static pressures recorded through the transmural cannulas and the intraurethral catheter. More than 300 pressure measurements were made in 14 dogs (both male and female). The results suggested that 1) static pressure increases with increasing rates of infusion, 2) when constrictions are applied in the midurethra, the increase of pressure is greater in the proximal (upstream) than the distal (downstream) urethral segments, 3) the total urethral pressures were (4 to 10%) higher than the static pressures, and 4) although statistically not significant, the static pressures recorded through the urethral catheter were lower than those recorded through the extraluminal transmural cannula.