Original Paper
Urologia Internationalis
Received: June 10, 2014 Accepted after revision: August 22, 2014 Published online: January 20, 2015
Urol Int 2015;95:33–37 DOI: 10.1159/000367811
Is Prolonged Operation Time a Predictor for the Occurrence of Complications in Ureteroscopy? Sophie Knipper Christian Tiburtius Andreas J. Gross Christopher Netsch Department of Urology, Asklepios Hospital Barmbek, Hamburg, Germany
Abstract Objective: To determine the impact of duration of ureteroscopy for urolithiasis on complication rates (CRs) of the procedure. Methods: A retrospective analysis of 2,010 patients, treated between 2006 and 2011, was done. The operation time (OT) and the occurrence of complications were compared. Results: The overall CR was 14.3% [298 complications, minor complications (Clavien I–II) 91.7%]. The median OT was 35 min [interquartile range (IQR) 20–61]. The OT differed significantly between those without complications [34 min (IQR 20–60)] and those with complications [45 min (IQR 25– 76)] (p < 0.0001). The correlation between the OT and the occurrence of complications (r = –0.009648, p < 0.0001) was very weak and passed the level of significance (r = 0.2). The effect size was of minor relevance (Cohen’s d = 0.27972). Conclusions: Longer OT correlates significantly with a higher CR. The effect is however shown to be minor and the overall rate of complications, especially severe ones, is low. © 2015 S. Karger AG, Basel
© 2015 S. Karger AG, Basel 0042–1138/15/0951–0033$39.50/0 E-Mail [email protected] www.karger.com/uin
Introduction
Urolithiasis is a common human affliction with an increasing prevalence and incidence worldwide [1]. Prevalence rates of 4.7% [2] and 8.8% [3] have recently been reported for Germany and the USA, respectively. This leads to increasing utilization of interventional modalities: ureterorenoscopy (URS) has become a popular minimally invasive procedure in the armamentarium of urolithiasis treatment [4–7]. Stone-free rates (SFRs) of up to 97%, depending on stone size and stone location, with low complication rates (CRs) of 3.5–25%, have been reported [4–7]. The occurrence of complications is stated to depend on various factors, such as stone size, stone width in ureteral stones, stone location, ureteral stone impaction and surgeon’s or department’s experience [8–13]. URS has also been successfully applied on larger-sized or multiple calculi of the upper urinary tract [14–18], which otherwise extends the duration of the URS procedure significantly. Longer duration of the URS procedure has however been shown to be strongly associated with ureteral perforation [10]. The aim of our study was therefore to determine the impact of the operative duration of URS for urolithiasis on the CR of the procedure. Dr. med. S. Knipper Department of Urology, Asklepios Hospital Barmbek Rübenkamp 220 DE–22291 Hamburg (Germany) E-Mail s.knipper @ asklepios.com
Downloaded by: Chinese University of Hong Kong 198.143.53.33 - 1/26/2016 10:59:24 PM
Key Words Ureteroscopy · Complications · Urolithiasis
Table 1. Patient characteristics, stone characteristics and surgery outcome after one URS procedure
Patients Age, years BMI, kg/m2 Stone size, mm Stones/patient SFR Gender Male Female Preoperative stents Postoperative stents Holmium laser lithotripsies Scope type Semirigid Flexible Flexible + semirigid Surgeons Consultants Residents OT, min
Total
Without complications
With complications
p value
2,010 52 [41–64] 26.6 [24.1–30] 7 [5–10] 1 [1–2] 1,716 (85.4%)
1,712 52 [51–64] 26.6 [24.1–30.1] 7 [4.5–10] 1 [1–2] 1,500 (87.6%)
298 53.5 [40–67] 27.05 [24.1–30.14] 8 [5–14.08] 1 [1–2] 216 (72.5%)
n.s. n.s.
Urologia Internationalis
Received: June 10, 2014 Accepted after revision: August 22, 2014 Published online: January 20, 2015
Urol Int 2015;95:33–37 DOI: 10.1159/000367811
Is Prolonged Operation Time a Predictor for the Occurrence of Complications in Ureteroscopy? Sophie Knipper Christian Tiburtius Andreas J. Gross Christopher Netsch Department of Urology, Asklepios Hospital Barmbek, Hamburg, Germany
Abstract Objective: To determine the impact of duration of ureteroscopy for urolithiasis on complication rates (CRs) of the procedure. Methods: A retrospective analysis of 2,010 patients, treated between 2006 and 2011, was done. The operation time (OT) and the occurrence of complications were compared. Results: The overall CR was 14.3% [298 complications, minor complications (Clavien I–II) 91.7%]. The median OT was 35 min [interquartile range (IQR) 20–61]. The OT differed significantly between those without complications [34 min (IQR 20–60)] and those with complications [45 min (IQR 25– 76)] (p < 0.0001). The correlation between the OT and the occurrence of complications (r = –0.009648, p < 0.0001) was very weak and passed the level of significance (r = 0.2). The effect size was of minor relevance (Cohen’s d = 0.27972). Conclusions: Longer OT correlates significantly with a higher CR. The effect is however shown to be minor and the overall rate of complications, especially severe ones, is low. © 2015 S. Karger AG, Basel
© 2015 S. Karger AG, Basel 0042–1138/15/0951–0033$39.50/0 E-Mail [email protected] www.karger.com/uin
Introduction
Urolithiasis is a common human affliction with an increasing prevalence and incidence worldwide [1]. Prevalence rates of 4.7% [2] and 8.8% [3] have recently been reported for Germany and the USA, respectively. This leads to increasing utilization of interventional modalities: ureterorenoscopy (URS) has become a popular minimally invasive procedure in the armamentarium of urolithiasis treatment [4–7]. Stone-free rates (SFRs) of up to 97%, depending on stone size and stone location, with low complication rates (CRs) of 3.5–25%, have been reported [4–7]. The occurrence of complications is stated to depend on various factors, such as stone size, stone width in ureteral stones, stone location, ureteral stone impaction and surgeon’s or department’s experience [8–13]. URS has also been successfully applied on larger-sized or multiple calculi of the upper urinary tract [14–18], which otherwise extends the duration of the URS procedure significantly. Longer duration of the URS procedure has however been shown to be strongly associated with ureteral perforation [10]. The aim of our study was therefore to determine the impact of the operative duration of URS for urolithiasis on the CR of the procedure. Dr. med. S. Knipper Department of Urology, Asklepios Hospital Barmbek Rübenkamp 220 DE–22291 Hamburg (Germany) E-Mail s.knipper @ asklepios.com
Downloaded by: Chinese University of Hong Kong 198.143.53.33 - 1/26/2016 10:59:24 PM
Key Words Ureteroscopy · Complications · Urolithiasis
Table 1. Patient characteristics, stone characteristics and surgery outcome after one URS procedure
Patients Age, years BMI, kg/m2 Stone size, mm Stones/patient SFR Gender Male Female Preoperative stents Postoperative stents Holmium laser lithotripsies Scope type Semirigid Flexible Flexible + semirigid Surgeons Consultants Residents OT, min
Total
Without complications
With complications
p value
2,010 52 [41–64] 26.6 [24.1–30] 7 [5–10] 1 [1–2] 1,716 (85.4%)
1,712 52 [51–64] 26.6 [24.1–30.1] 7 [4.5–10] 1 [1–2] 1,500 (87.6%)
298 53.5 [40–67] 27.05 [24.1–30.14] 8 [5–14.08] 1 [1–2] 216 (72.5%)
n.s. n.s.
