Quantitative biomechanical analysis of ureteral obstruction and peristalsis

Abstract

Malignant ureteral obstruction may lead to renal function damage, renal colic, and infection. The impact of obstructive development on ureteral peristalsis was rarely studied, which requires further investigation. This study used theoretical biomechanical methods to study the motion characteristics of the ureteral wall and obtained the radial motion equation of the ureteral wall. The motion equation was solved by 4–5th order Runge Kutta method. Analyze the motion equation of the ureteral wall, derive the expression for malignant obstructive ureteral pressure, as well as the analytical expressions for radial displacement and circumferential stress of the ureteral wall. By analyzing the radial motion equation of the ureter, it can be found that peristalsis is influenced by the pressure difference between inside and outside. The analytical solutions for radial displacement and stress contained exponential terms. Under the condition of 50% obstruction, the displacement and stress of the ureter were reduced by 90.53% and 81.10%, respectively. This study established the radial motion equation of the ureter and provided analytical solutions for the radial displacement and stress of the obstructed ureter. Based on the radial motion equation of the ureter, the radial motion characteristics of the ureteral wall were explored, including peristalsis and disappearance of peristalsis. This study provided a quantitative relationship between ureteral obstruction and peristalsis. As the degree of obstruction increased, ureteral peristalsis gradually weakened or even disappeared.