Category: Clinical Stones: SWL

MP31-19 - Can we Predict the Ancillary Treatments after Extracorporeal Shockwave Lithotripsy for Renal and Upper Ureteral Stones?

Sun, Sep 23
2:00 PM - 4:00 PM

Introduction & Objective :

Ancillary treatments such as ureteroscopy and hospital readmission for pain or fever are frequently encountered after extracorporeal shockwave lithotripsy (SWL). These ancillary treatments have put an undue burden on urological treatment waiting lists. However, the predictors for these procedures are still under investigated. Therefore, the aim of the present study was to investigate the predictors for the ancillary treatments after (SWL) for renal and upper ureteral stones.


Methods :

From January 2013 to January 2016, patients undergoing SWL using electromagnetic lithotripter machine (Compact Delta; Dornier MedTech GmbH, Wessling, Germany) for renal and upper ureteral stones ≤ 20 mm were retrospectively reviewed. All patients underwent CT urography prior to SWL. The cohort was subdivided into three groups according to stone attenuation values (HU). Group I; HU ˂500 (n=20), group II; HU between 500-1000 (n=51) and group III; HU ≥ 1000 (n=180). The parameters included in the multivariate analysis were stone size, location, multiplicity, stone attenuation value, number of shocks and stone clearance rate at the end of 3 months. The ancillary treatments were ureteroscopy (URS), ureteral stenting and hospital readmission for pain or fever.


Results :

A total of 251 patients were included in the study. The overall SWL success rate was 92.4%, the mean stone size was 10.9±2.1, 11.6± 3 and 11.4±3.6 mm and the mean stone attenuation values were 364±125, 811±154 and 1285±171 for group I, II, III respectively. The stone clearance rate was 96%, 92%, 88.4% for group I, II, III respectively. On subgroup analysis, group III required URS and ureteral stenting in 10 cases (50%), and hospital readmission for persistent renal colic in 4 cases (20%) whereas group I, II, did not require any ancillary treatments. On multivariate analysis, stone multiplicity, stone location (lower calyceal stones) and HU were independent significant predictors for the treatments after SWL (p values


Conclusions : Patients withstone attenuation value (HU) >1000, multiple stones and/or lower calyceal stones have higher risk to necessitate ancillary treatments after SWL. Those patients could be offered an endoscopic lithotripsy as a first line therapy for treating symptomatic renal or upper ureteral stones. Future prospective studies are definitely warranted

Ahmed I.M. Ibrahim

Endourology Fellow
McGill University Health Centre
Montreal, Quebec, Canada

Dr. Ahmed Ibrahim is an Endourology clinical research fellow at McGill University Health Centre, Montreal, QC, Canada. He graduated from Al-Azhar medical school, Cairo, Egypt where he completed his urology residency training program in 2016.

His Current research interests include role of virtual reality simulators in surgical educations, minimally invasive treatment of urinary tract stones and role of different lasers in management of bladder outlet obstruction.

Adel Elatreisy

Urology Department, Al-Azhar University, Cairo
Cairo, Al Qahirah, Egypt

Ahmad Al-hadi

Head of the department
Military Hospital, Khamis Mushait
Khamis Mushait, Asir, Saudi Arabia

Ismail Khalaf

Urology Department, Al-Azhar University, Cairo
Cairo, Al Qahirah, Egypt

Serge Carrier

McGill University Health Centre
Montreal, Quebec, Canada

Arvind Ganpule

Vice Chairman
Muljibhai Patel Urological Hospital
Nadiad, Gujarat, India

Mahesh Desai

Consultant Urologist and Managing Trustee
Muljibhai Patel Urological Hospital
Nadiad, Gujarat, India