Intravesical aminophylline instillation as an alternative for balloon dilatation prior to semi-rigid ureteroscopic management of distal ureteral stones

PURPOSE: In a randomized controlled trial, we evaluated the effect of intravesical aminophylline instillation (IVAI) on intraureteral pressure of lower ureter and its use as an alternative to balloon dilatation after failure of advancing semi-rigid ureteroscope through the ureteric orifice without endodilatation. METHODS: Our study included 83 patients with juxta-vesical distal ureteral calculi requiring endodilatation after unsuccessfully introducing the semi-rigid ureteroscope through the ureteric orifice. Patients were randomized into two groups: group A (study group) included 41 patients, where IVAI was used to dilate the ureter and facilitate ureteroscopy (the intraureteral pressure was measured using a pressure transducer connected to an invasive pressure monitor before and 5 min after IVAI), whereas group B (control group) included 42 patients, where balloon dilatation was used prior to ureteroscopy. Perioperative surgical outcomes of ureteroscopy were evaluated in both groups. RESULTS: A statistically significant decrease in mean intraureteral pressure of intravesical ureter was found after IVAI from 12.34 mmHg ± 1.94 before injection to 8.46 mmHg ± 1.94 after injection (P < 0.001). Ureteral injuries, postoperative pain and hematuria were statistically significantly less among the study group compared to the control group (P < 0.05). We did not find statistically significant differences in operative time, need for DJ ureteral stenting or stone-free rate between both groups and no perioperative side effects were associated with IVAI. CONCLUSION: In ureteroscopic management of distal ureteral stones, intravesical aminophylline instillation is safe, inexpensive and effective in reducing intraureteral pressure and achieves comparable outcomes to balloon dilatation with less ureteral injuries, postoperative pain and hematuria.