Is Guy's stone score useful for predicting outcomes in percutaneous nephrolithotomy?

Actas Urol Esp (Engl Ed). 2022 Mar;46(2):92-97. doi: 10.1016/j.acuroe.2021.01.009. Epub 2022 Feb 4.
[Article in English, Spanish]

Abstract

Introduction: Percutaneous Nephrolithotomy (PCNL) is currently the treatment of choice in large kidney stones. Guy's stone score was developed to predict treatment outcomes. The aim of this study was to evaluate the relationship between Guy's score and outcomes in our institution.

Materials and methods: The medical records of patients diagnosed with urolithiasis and treated by PCNL were retrospectively evaluated between January 2017 and December 2018. Analyzed data included: age, sex, Guy's score based on preoperative findings, transfusion, stone-free rate and requirement of auxiliary procedures. Chi-square test was used for the comparison of proportions. Odds ratios (OR) with confidence intervals (CIs) of 95% were calculated by logistic regression.

Results: A total of 386 patients, 53.89% female, mean age of 45.59 ± 15 years were analyzed. Guy's score was as follows: 112 patients (29.04%) were classified as Guy I, 92 patients (23.82%) as Guy II, 94 patients (24.34%) as Guy III, and 88 patients (22.80%) as Guy IV. There were no differences between groups in terms of blood transfusions. Stone-free rate was 96.43% (n = 108) for patients Guy I; 84.78% (n = 72) for Guy II; 76.59% (n = 72) for Guy III and 50% (n = 44) for Guy IV categories (p < 0.0001). Taking as a reference Guy I group, the OR to require new treatment for residual stones were: Guy II 4.85 (CI = 0.95 to 24.60, P = 0.05) to Guy III 8.25 (CI = 1.73 to 39.44, P = 0.008) and Guy IV 27 (CI = 5.84 to 124.70; p < 0.0001).

Conclusion: There was a statistically significant association between Guy's Score and stone-free rates following PCNL. Guy's score was useful to predict results of PCNL in our group.

Keywords: Endourology; Endourología; Lithiasis; Litiasis; Nefrolitotomía percutánea; Percutaneous nephrolithotomy.

MeSH terms

  • Adult
  • Female
  • Humans
  • Kidney Calculi* / surgery
  • Male
  • Middle Aged
  • Nephrolithotomy, Percutaneous*
  • Retrospective Studies
  • Treatment Outcome
  • Urolithiasis*