Reasons for early readmission after percutaneous nephrolithotomy and retrograde intrarenal surgery

Introduction: Hospital readmissions are frequent and costly. In many countries health governors focus on unplanned postsurgical hospital readmissions as an objective metric for quality of care. Aim: To investigate the rate of readmissions after retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) operations, classify these factors, define the higher risk patients for readmission and develop prevention strategies. Material and methods: A historical cohort study was conducted for a period of 36 months, between 2013 and 2016. A total of 471 consecutive patients, of whom 177 had PCNL (37.6%) and the remaining 294 had RIRS (62.4%), were included. The two groups were compared in terms of stone burden, previous stone treatments, initial symptoms, ASA class, intra-operative complications, post-operative stenting, and drugs prescribed at discharge, so as to find the factors influencing the readmission rate for both groups. Results: The PCNL operation was found to have a significantly higher risk for readmission when compared to RIRS (27.1% vs. 20.4%, respectively, p = 0.0041). Perioperative complications (p = 0.002 for PCNL and p = 0.001 for RIRS), residual stone(s) or fragments after the operation (p = 0.002 for PCNL and p = 0.001 for RIRS) significantly increased the readmission rate in both groups. The readmission rates were individually affected by postoperative JJ stent placement in the PCNL group (p = 0.001) and previous stone treatments for the RIRS group (p = 0.001). Conclusions: Readmission rates were higher in the PCNL group, but the influencing factors were similar for both groups. The presence of multiple stones preoperatively and residual stones or fragments postoperatively are the most important risk factors for early re-admission after PCNL and RIRS.