Intermittent gross hematuria after lithotripsy: ureteral stent or residual stone?

PurposeTo explore the role of stone fragment and ureteric stent in process of intermittent gross hematuria (IGH), discuss the definition of ureteral stent related symptoms (USS) in a setting of lithotripsy and clinical outcomes of IGH. MethodsBetween January 2018 and July 2019, patients with completed one month follow up after lithotripsy were collected. Based on whether occurrence of IGH, demographics, stent information and clinical outcomes were mainly analyzed. ResultsA total of 258 consecutive patients were eventually analyzed, among which 97 patients (37.6%) suffered from IGH. Compared to patients without symptom of IGH, preoperative potassium level (3.89{+/-}0.43mmol/L vs. 4.02{+/-}0.42mmol/L, p=0.01), initial stone free rate (SFR, 50.52% vs. 68.32%, p=0.007) and potassium citrate application (11.34% vs. 4.55%, p=0.04) were found statistically different in univariate analysis. In multivariate logistic analysis, preoperative potassium level (OR: 0.39, CI: 0.19-0.76, p=0.007), potassium citrate (OR: 2.96, CI: 1.07-8.73, p=0.04), initial SFR (OR: 0.42, CI: 0.24-0.74, p<0.001), and hospital stay (OR: 0.94, CI: 0.89-0.99, p=0.045) were independent risk factors, rather than stent size and stent position. Hemoglobin change, stone area reduction and SFR in one-month follow-up were similar between groups, but more outpatient consultations were found in hematuria group (20 vs. 3, p<0.001), among which 2 patients were readmitted for severe ongoing hematuria. ConclusionsStone fragment, rather the size or length of ureteral stent, is the independent risk factors of IGH. Definition of USS is not suitable for IGH after lithotripsy, and a comprehensive inform and enough rest would reduce the unnecessary medical consultations.