The Effects of Ureteral Mobilization and Transection on Ureteral Oxygenation

ObjectivesTo determine the impact of ureteral transection with and without prior ureteral mobilization on ureteral oxygen partial pressure (puO2).MethodsSixteen pigs underwent general anesthesia with laparoscopic transperitoneal access to the right ureter. With no dissection and minimal manipulation, a tissue oxygen probe (Licox, Kiel, Germany) was introduced via a trocar and inserted into the ureter. The probes were placed at the ureteropelvic junction (UPJ, n = 8) and ureterovesical junction (UVJ, n = 8). Baseline puO2 was measured. Subsequently, half of the animals at each level (n = 4) underwent complete ureteral transection proximal to UPJ probes and distal to UVJ probes with or without prior mobilization. puO2 levels were measured after ureteral mobilization and transection.ResultsOf the ureters transected at the UPJ without mobilization, the mean puO2 level declined by 13 mm Hg relative to baseline (P = 0.07). The baseline UPJ puO2 level declined by 5 mm Hg after ureteral mobilization alone and subsequently by 31 mm Hg after transection (P <0.01). Of the ureters transected at the UVJ without mobilization, the puO2 level decreased by 4 mm Hg relative to baseline (P = 0.08). The baseline UVJ puO2 level decreased by 15 mm Hg after ureteral mobilization alone and subsequently by 39 mm Hg after transection (P <0.01). At both the UPJ and UVJ, the transected-only puO2 level was statistically higher than the mobilized and transected level (P = 0.03, respectively).ConclusionsDuring ureteral surgery, mobilization alone exposes the distal ureter to more ischemia than the proximal ureter, and efforts to minimize ureteral mobilization when transection is necessary are crucial in maintaining tissue oxygenation.