Indications for Intervention in Patients Undergoing Ureteroscopic Therapy for Ureteric Calculus: A Cross-sectional Study

Abstract

Introduction: Urolithiasis is one of the most common urological problems worldwide. The fastest treatment modality to achieve stone clearance of ureteral stones is Ureteroscopic Lithotripsy (URSL). However, it is negated by both the cost burden and potential risk to the patient. Medical Expulsive Therapy (MET) is a treatment option for upto 10 mm stones but has failure rates of 40-60% in the literature. Aim: To analyse the various indications for surgery, whether MET was used or not, if used-its details, operative findings at ureteroscopy including the reason for the failure of MET. Materials and Methods: A cross-sectional study consisting of 72 patients with ureteric calculi undergoing URSL was analysed from June 2017 to December 2018 at Mazumdar Shaw Medical Centre, Bangalore, Karnataka, India. Indications were assessed at the time of admission. During ureteroscopy, factors like impaction, distal obstruction, and unusual findings were studied, which could have contributed to the failure of MET. The Chi-square test was used as a test of significance for categorical data. The Analysis of Variance (ANOVA) test was used as a test of significance to identify the mean difference between continuous variables. The p-value of <0.05 was considered statistically significant. Results: The mean age in the study was 41.65±13.4 years (range 20-69 years), and the mean stone size was 10.03±3.34 mm. Large stone was the most common indication (41, 56.9%, p=0.004), followed by failed MET (35, 48.6%). Even though MET could have been continued for four weeks in 17 patients (23.6%), they were taken up for surgery. The impaction rate was 70.8% (51), with 48.6% (35) being large impacted stones and 22.2% (16) being small impacted stones. The overall stone clearance rate was 68 out of 72 (94.4%). Conclusion: Large stone size (≥10 mm) and failed MET were the main indications for surgery. One reason for the failure of MET was not waiting for a duration of four weeks. During ureteroscopy, impaction of the stone, irrespective of size, was the most common finding and was the reason for the failure of MET. Ureteric stones on MET should not be neglected as there are reasons for the failure of MET, and they will require URSL after four weeks.

Keywords

• failed medical expulsive therapy
• laser lithotripsy
• ureteroscopy