Presentation Authors: Katharine Michel*, Philadelphia, PA, Hiten Patel, Brian Matlaga, Baltimore, MD, Justin Ziemba, Philadelphia, PA
Introduction: Unanticipated revisits after surgical removal of urinary calculi is relatively common. However, these data are largely derived from single institution studies. Therefore, we use state level databases to accurately identify this rate.
Methods: The AHRQ-sponsored databases for NY and FL contain all-payer, encounter-level data for ambulatory surgical procedures, inpatient admissions (IP), and emergency department (ED) visits. From this database, we identified index cases by filtering for a primary CPT code for percutaneous nephrolithotomy (PNL), shock-wave lithotripsy (SWL), or ureteroscopy (URS) with a primary ICD-9 code for calculus for kidney or ureter from 2010-14. For comparison we identified a low-risk control case as a primary CPT code for cystoscopy (CYS) with ICD-9 code for microscopic hematuria. Revisits were defined as a return to either ED or IP within 30 days of the index procedure.
Results: A total of 211,619 cases met our inclusion criteria with CYS, SWL, URS, and PNL representing 18,678 (8.8%), 109,629 (51.8%), 80,128 (37.9%), and 3,184 (1.5%), respectively. Figure 1 shows the percentage of ED and IP revisits for each procedure by year. The median (IQR) days to revisit were 14 (7-22), 8 (3-17), 6 (3-14), and 7 (3-14) for CYS, SWL, URS, and PNL, respectively. There was a significantly higher proportion of ED and IP revisits for each stone procedure compared to control (one-sided z tests; all p < 0.0001). SWL had a significantly lower proportion of ED revisits compared to both URS and PNL (one-sided z; both p < 0.01), but there was no difference in ED revisits between URS and PNL (one-sided z; p=0.47). IP readmissions between stone procedures were all significantly different with PNL having the highest proportion, then URS, then SWL (one-sided z; all p < 0.01). The most common reasons for revisit are displayed in Figure 2.
Conclusions: Revisits after endoscopic stone removal are relatively frequent. Recurrent calculi and infection are the most common reasons.