Predicting Percutaneous Nephrolithotomy Outcomes and Complications in Elderly Patients Using Guy's Scoring System and Charlson Comorbidity Index

Background: This study compared the operative outcomes of percutaneous nephrolithotomy in elderly patients with different comorbidity status and different stone complexity. Methods: A retrospective review of medical records was performed of 113 patients aged 65 years or older with large renal stones who underwent percutaneous nephrolithotomy between 2007 and 2016. Patients were stratified by comorbidity status using the Charlson comorbidity index and by stone complexity using the Guy's score. The demographic data, stone parameters, stone-free rates, and complication rates were compared. Factors associated with complications and stone free rate were analyzed using logistic regression. Results: Patients with higher Charlson comorbidity index were older, used more anticoagulant medications, had higher ASA score, had longer operative times, and had longer hospital stay. Patients with higher Guy's score had higher stone burden, longer operative times, and a more significant decrease in GFR postoperatively. Logistic regression found that pre-operative pyuria and higher Charlson comorbidity index increased the risk of overall complications, and higher stone burden and higher Guy's score were associated with decreased stone free rates. Conclusion: This study supported the use of the Charlson comorbidity index in predicting post-operative complications and the Guy's score in predicting stone-free status in elderly patients with large renal stones undergoing percutaneous nephrolithotomy.