Upper urinary tract stone characteristics and outcome of retrograde intra renal surgery with laser lithotripsy in a Nigerian tertiary hospital: a retrospective study.

Abstract

Background: This study is therefore aimed at assessing upper urinary tract stone characteristics, the outcome of retrograde intrarenal surgery with laser lithotripsy, and factors predicting stone-free status.

Methodology: This was a retrospective cross-sectional study carried out on all patients who had retrograde intra-renal surgery with laser lithotripsy for upper urinary tract stones from 2021-2023 at the Urology unit, department of Surgery, University of Benin Teaching Hospital. Electronic medical records were retrieved with data on demographics, serum calcium level, and non-contrast computed tomography scans assessing stone size, location, laterality, multiplicity, density, and renal anatomy.

Results: The data Thirty- three patients were extracted and analysed with a mean age of 43,70+/- 11.44 years, 54.5% of patients were male. The mean duration of admission was 2.4+/-1.5 days. The mean body mass Index was 26.84+/- 4.37 kg/m2. All patients had flank pains; 7(41.2%) patients had bilateral renal stones. The majority of renal stones 8(47.1%) were located in the lower pole of the kidney. A greater proportion of calculus was ureteric 23(69.7%), mean stone size was 13.2+/- 15.2mm, while mean stone density was 817+/- 285.5 HU. Fifteen participants (45.5%) had multiple stones. Stone clearance assessed on imaging was 75.8%. Age, sex, stone size, density and location, and multiplicity of stones were statistically significant determinants of stone clearance (p= 0210, 1.000, 0.220, 0.380. 0.366 and 1.000) respectively, similarly, no statistically significant predictors of stone clearance were found in this study.

Conclusion: The study revealed a predominance of upper urinary tract stones in males, with most patients being overweight. There was a weak correlation between stone density and serum calcium level in this study. Findings in this study revealed no statistically significant determinant or predictors of stone clearance.