Intravenous Pyelogram (IVP)-Based Guy’s Stone Score (GSS) Utility for Prediction of Outcomes of Upper Pole Access Percutaneous Nephrolithotomy (PCNL)

Abstract

Background: Renal stone disease is a very common disease, and its lifetime prevalence is 1 - 15%, with a gradual rise in incidence and disease prevalence. There are significant financial implications of its management. Nowadays, for big (typically > 2 cm) renal and upper ureteric stones, PCNL is widely regarded as the first-line treatment. Because most of the intrarenal collecting systems can be accessed by superior calyceal puncture in PCNL, good stone clearance can be achieved. The “Guy’s Stone Score” is a useful technique for categorizing the complexity of PCNL. Objectives: This study aimed to evaluate the role of Guys Stone Score based on KUB and intravenous urography to predict the success rate, grading, and complexity of PCNL, which are performed via the upper pole access. Methods: The present prospective, non-randomized observational study was undertaken in the Department of Urology and Renal transplantation, SCBMCH, Cuttack, from 1st November 2017 to 31st October 2019. A total of 104 patients were enrolled in the study in whom PCNL was performed through superior calyceal puncture, based on preoperative intravenous pyelogram. The Guy's Stone Score was calculated, and the complexity of the procedure was graded using radiological studies, then the outcome was determined accordingly. Results: In this study, 59.6% of the patients had immediate success among them 29.0% had grade 3, and 6.5% had grade 4 GSS. Moreover, 38.4% of the patients had clinically significant residual fragments among them, 75.0% had grade 4, and 20.0% had grade 3 GSS.23% of the patients underwent REDO-PCNL and 11.5% of the patients underwent necessary procedure of ESWL. Conclusions: The present study shows that an intravenous pyelogram-based Guy’s Stone Score (GSS) is an easy-to-use tool in predicting the early success rate and potential difficulties and complications in PCNL performed through superior calyceal puncture.