A practical pressure measuring method for the upper urinary tract during ureteroscopy

Abstract

Purpose: The purpose of this study was to develop and test a method for measuring pressure in the upper urinary tract during ureteroscopic operations and to evaluate its efficacy and clinical significance. Methods: A total of 44 patients, each with a ureteral calculus in the proximal ureteral segment, were enrolled in the study group: 21 patients with an acute and 23 with a chronic obstruction. The ureteroscope was passed forward to the upper segment of the obstructed ureter immediately after the calculus was broken and the intraluminal ureteral pressure was then transmitted along with the irrigant flow (0.9% sodium chloride). Results: The mean ureteral pressures of the acute obstruction subgroup, the chronic obstruction subgroup and the control group were 74.5 mmHg (22-180 mmHg), 32.5 mmHg (9-53 mmHg) and 10.2 mmHg (8-13 mmHg), respectively. A significant correlation was found between ureteral pressure and the following indexes: the duration of the obstruction (r=0.985), the diameter of the ureter above the calculus (r=0.878) and the depth of the hydronephrosis of the renal pelvis (r=0.862). No associations were observed between the pressure and the serum creatinine level (r=0.214) or the urinary leukocyte count (r=0.047). The intraluminal pressure correlated with the glomerular flow rate (GFR) of the affected kidney (r =0.975, P =0.001). Conclusions: This new method is non-invasive, practical and reproducible. Measuring the intraluminal pressure of the ureter can provide a valuable index to quantify the severity of the obstruction of the upper urinary tract, which is helpful for the prediction of the affected renal function prognosis.