Can extracorporeal shock wave lithotripsy (SWL) session intervals affect success in the treatment of upper ureteral stone?

By: Turan T., Danacıoğlu Y.O., Efiloğlu Ö., Günaydın B., Atış R.G., Yıldırım A., Çaşkurlu T.
Institutes: Istanbul Medeniyet University, Dept. of Urology, Istanbul, Turkey

Introduction & Objectives

Management of the upper ureteral stones with SWL has been performed for many years. EAU guidelines recommend SWL as a first line therapy for ureteral stone smaller than 10 mm. But, no conclusive data is found out on the intervals required between repeated SWL sessions. In this study, we aim to determine optimizing the extracorporeal shock wave lithotripsy intervals in repeated SWL sessions.

Material & Methods

Between 2015, September and 2016, December, 80 patients (54 men, 26 women) undergoing elective outpatient lithotripsy who required repeat SWL sessions for ureteral stones were evaluated. The study is designed as a prospective and randomized trial. Patients were categorized into two groups according to SWL session interval. SWL repeat sessions for the first group (n: 40) has one day and the second group (n: 40) has one week interval. Data recording during SWL includes visual analog scale (VAS), total number of shocks, used total energy and the number of sessions. Plain Xray of the urinary tract and pelviabdominal ultrasound are repeated to confirm stone clearance after SWL sessions. We compare stone clearance rate, number of urinary tract infection, complications rate and VAS between two groups. Statistical analysis is performed using SPSS version 21.


All patients’ clinical outcomes of SWL therapy are showed in Table 1. The mean age and body mass index, mean Hounsfield Unit are similar in both groups. The stone clearance rate for Group 1 was 70% and Group 2 was 72,5%, respectively (p=0,805). And also, the number of urinary tract infection, complications rate and VAS are similar in both groups. In Group 1, 3 patients have steinstrasse, 2 patients have severe renal colic, 1 patient has urinary tract infection and in Group 2, 3 patients have steinstrasse, 2 patients have severe renal colic occurred during the study. All patients with SWL failure undergo with endoscopic surgery.

  Group 1 (n:40) Group 2 (n:40) P
Age (Mean ±SD) 41,4±12,9 44,7±16,3 0,394
M/F ratio 28/12 26/14 0,613
BMI (kg/m2) 27±3,5 28,6±6,3 0,234
Stone Size (mm) 10,2±2,82 10,23±2,87 0,964
Left /Right side 14/26 28/12 0,002
Hounsfield U. (Mean ±SD) 869,16±266,3 869,3±251,1 0,998
Average total energy  (j) 92,2±24,4 89,97±33,4 0,496
VAS (1. Sessions) 4,2±1,1 4,2±1,2 0,918
VAS (2. Sessions) 4,23±1,1 4,4±1,2 0,599
VAS (3. Sessions) 4,27±1,6 (n:19) 4,6±1,4 (n:16) 0,601
Minor complications n (%) 6 (15%) 5 (12,5%) 0,688
Stone clearance n (%) 28 (%70) 29 (%72,5) 0,805


Short interval SWL sessions are safe and effective for upper ureteral stones. Short interval SWL sessions do not increase the rate of complication.  So, if early result is expected from SWL, short interval sessions can be recommended as an indicated active therapy for ureteral stones.

  • Event: 4th Meeting of the EAU Section of Urolithiasis (EULIS)
  • Type: Abstract
  • Date: 01-01-1970
  • Views: 19
  • Nr: 85