Category: Clinical Stones: SWL

MP9-15 - To Investigate the Effect Of Power Ramping On Treatment Outcome In Extracorporeal Shockwave Lithotripsy Of Renal Calculi

Fri, Sep 21
2:00 PM - 4:00 PM

Introduction & Objective :

To assess the effects of voltage escalation in patients receiving SWL for renal stones, particularly on treatment success and degree of renal injury, in term of post-SWL haematoma and also change in urinary level of acute renal injury markers.


Methods :

During Februray 2016 and March 201, 277 patients with renal stones were prospectively randomised to receive shockwave delivered at either power ramping (Group-1) or constant voltage (Group-2) in a single institute using Modulith SLX-F2 for maximum 3000 shocks at 1.5Hz. Primary outcome was successful treatment at 12-weeks after one session of lithotripsy, as defined as stone free or stone fragment < 4mm on computerized tomography. Secondary outcome measures included stone free rate, incidence of perinephric haematoma, as access by post-treatment imaging, and also changes in urinary level of acute renal injury markers. 


Results :

There were 277 patients, 139 patients in Group-1 & 138 patients in Group-2, were recruited during the study period and completed 12-week follow-up. The mean stone size for Group-1 and -2 were 9.0mm and 9.2 mm respectively. There was no difference between the other baseline parameters of the twogroups.Group-1 has received lower energy shockwaves (pp=0.045).Both groups had similar unplanned hospital admission rate.There was a statistically significant rise in urinary N-acetyl-beta-D-glucosaminidase, interleukin-18, KIM-1 and albumin level in both groups after SWL. However, there was no between-group difference in the urinary markers level. All markers level returned to baseline level at 6 weeks after SWL. 


Conclusions :

When compared to constant voltage SWL, power ramping could provide similar stone free and treatment successful rate for renal stone less than 15mm. However, it could significantly decrease the incidence of post-SWL perinephric haematoma. (The project is supported by Hong Kong General Research Fund Project number 14113515)

Chi-Fai Ng

Director and Professor
S.H. Ho Urology Centre, Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China.
Hong Kong, Not Applicable, Hong Kong

Dr NG Chi Fai, Anthony graduated in the Chinese university of Hong Kong in 1993. He then joined Department of Surgery, Prince of Wales Hospital, as surgical trainee. After his basic training, he decided to become an urologist and became a specialist in 2001. Attracted by the rapid development in endourology, he spent one year in Scotland, worked under Mr David Tolley, and gained extensive experience in endo-laparoscopic surgery and stone management.

After completion of his training, Dr Ng decided to join the Chinese University of Hong Kong in 2006 and is currently Director and Professor of the S.H. Ho Urology Centre, Department of Surgery, the Chinese University of Hong Kong. He is also the Course Director of the Robotic Surgery Training Programme, CUHK Hong Kong Jockey Club Minimally Invasive Surgical Skill Centre. He has a wide range of interest, in particular in prostate diseases, urolithiasis, and promotion of men’s health. He was also honored with the Outstanding Young Urologist Award in 2010 by the Asian Congress of Urology, the International Guest Scholar 2012 of the American College of Surgeons, the World Chinese Urology Association Award 2014 and the Outstanding Contribution Award 2017 of the International Alliance of Urolithiasis, as recognitions to his work in the field.

Chi-Hang Yee

S.H. Ho Urology Centre, Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China.
Hong Kong, Not Applicable, Hong Kong

Jeremy Yuen-Chun Teoh

S.H. Ho Urology Centre, Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China.
Hong Kong, Hong Kong

Steven Leung

Hong Kong, Not Applicable, Hong Kong

Becky Lau

Hong Kong, Not Applicable, Hong Kong

Chiu Wing Chu

Hong Kong, Not Applicable, Hong Kong

Ka Tak Wong

Hong Kong, Not Applicable, Hong Kong