[Differences between the inpatient complication rate after ureterorenoscopy and the 30-day outcome reported by the patient - results of the German prospective BUSTER study].

Background: Following ureterorenoscopic stone removal (URS), patients are generally discharged after a short hospital stay, so that the estimation of complication rates is based on a narrow timeframe. Data derived from the so-called BUSTER-project (Evaluation of ureterorenoscopic stone management - results in terms of complications, quality of life and stone-free rates) were therefore analysed with respect to complication rates during hospital stay and patient-reported 30-day-complication rates and then correlated with quality of life (QoL) data.

Methods: Data of 307 patients undergoing URS were recorded in 14 German centres 01/2015 - 04/2015. Complications (classified according to the Clavien-Dindo classification, CDG) and data on QoL were additionally assessed 30 days after surgery, using questionnaires which were completed by 169/307 patients. The subgroups were analysed: no increase in CDG 30 days after surgery (n = 128), increase in CDG without any additional intervention (n = 39), and increase in CDG with an additional intervention (n = 2). The correlation between this categorisation and data on QoL were analysed by bivariate correlations according to Spearman's rank correlation coefficient (ρ). The impact of different clinic parameters on the endpoint "increase in CDG 30 days after surgery" was evaluated by a multivariate logistic regression model.

Results: During hospital stay, complications occurred in 13 patients (7.7 %, mostly CDG1). 30 days after surgery, 43 patients (25.4 %) reported complications (16 CDG2 and 2 CDG3). A statistically significant correlation was shown between an increase in CDG and all aspects of QoL, with the strongest correlation concerning pain (ρ = 0.425; p < 0.001). Stone size was the only factor associated with an independent impact on the endpoint "increase in CDG 30 days after surgery" (OR: 1.09; 95 % confidence interval [CI] 1.01 - 1.17; p = 0.040). Postoperative ureteral stenting had no significant impact on this endpoint, despite a remarkable odds ratio (OR: 4.19; 95 % CI 0.64 - 27.32; p = 0.134). This might be explained by a significantly imbalanced distribution of this covariate (86.4 % postoperative stenting).

Conclusions: Assessment of complications should exceed the timeframe of hospital stay, as complications increased within 30 days of surgery and were associated with impairment of QoL. Further studies have to evaluate if lower complication rates and better QoL might be achieved by abstaining from postoperative ureteral stenting.