To investigate the effect of the upper infundibulopelvic angle (UIPA) on the treatment of mature ampullary upper ureter calculi by ureteroscopic holmium laser lithotripsy.

The clinical data of 58 patients with upper ureteral calculi treated with hard ureteroscope in First Hospital of Shanxi Medical University from January 2019 to January 2021 were retrospectively analyzed. There were 17 males and 41 females, aged 34-71 years, with an average age of (42±11) years. All the included patients had unilateral upper ureteral calculi with a diameter of 0.8 cm-2.1 cm, an average of (1.3±0.8) cm. Preoperative non-enhanced CT and intravenous pyelography were performed to confirm the type of renal pelvis and the UIPA. Among them, 39 cases had UIPA <20°, 15 cases had UIPA between 21° and 30°, and 4 cases had UIPA >30°.

All the 58 patients were mature renal pelvis, and 5 patients was converted to flexible ureteroscopy. All five patients were males. Four had a UIPA of over 30°, and one had a UIPA between 21° and 30°. The success rate of one-time stone fragmentation using rigid ureteroscopy was 91.4% (53/58). The operation time of the 53 patients was (48±21) min. The postoperative hospitalization was (1.4±1.0) days. Double J tubes were removed 1-3 months after the operation, followed up for 1-3 months. During the follow-up, plain films of the urinary system were performed to confirm the stone clearance, and the stone clearance rate was 88.7%(47/53).

UIPA can preliminarily determine whether a rigid ureteroscope can enter the upper calyx and complete the lithotripsy. Combined with preoperative imaging analysis, UIPA can be used for upper ureteral stones to reduce the use of flexible ureteroscopes and the economic burden of patients.