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.