The treatment options for renal stones 10-20 mm include either extracorporeal shock wave
lithotripsy (SWL) or endourology (retrograde intrarenal surgery (RIRS) and percutaneous
nephrolithotomy (PNL).
SWL is an attractive treatment option for renal stones because it is non-invasive and
more acceptable for the patient and can be done under analgesia, sedation, or minimal
anaesthesia. However, the limitation of SWL includes a relatively lower stone-free rate
(SFR) and the need for repeated sessions and auxiliary procedures. The SFR after SWL is
affected by several factors, including body mass index (BMI), stone size, intrarenal
stone location, skin-to-stone distance (SSD), and stone density.
The EAU guidelines put endourology and SWL as two equal options in medium-sized non-lower
pole renal stones and did not give special attention to the stone density, which is an
important predictor for SWL outcome. Several studies reported that the number of SWL
sessions increased with increased stone attenuation value (SAV) and SFR decreased
significantly in high-density renal stone.
PNL and RIRS have good SFR compared to SWL but might entail a significant risk of
morbidity. The improved fURS instrumentation and lithotripsy technology, and development
of the miniaturized PNL technique, may lower the procedure-related complications and mPNL
and RIRS an alternative and excellent option for medium-sized and even large renal stones
The investigators hypothesize that addressing the stone density factor may give a clear
recommendation for medium-sized, high-density renal stones. They expected the superiority
for either mPNL or RIRS, regarding SFR, without increased morbidity.
The study aims to compare the outcome of mPNL, RIRS, and SWL for treatment of non-lower
pole, high-density renal stones of 10 to 20 mm size.
The study will include adult patients with non-lower pole, high-density (>1000 HU) renal
stones of 10 to 20 mm size.
Pre-operatively, patients will be evaluated by medical history taking, physical
examination. urinalysis, urine culture, complete blood cell count (CBC), liver function
tests, coagulation profile, blood urea nitrogen (BUN), serum creatinine, plain abdominal
X-ray and computed tomography for urinary tract (CT-UT), Eligible patients will be
randomly divided into 3 equal groups. PNL group, in which PNL procedures will be
performed using miniature nephroscope, RIRS group, in which RIRS will be performed using
flexible ureteroscope and SWL group, in which SWL procedures will be performed using
Dornier Lithotripter.
post-operatively, patients will be followed up regularly, for 3 months. The SFR,
complication rate, cost, patients' and surgeon's satisfaction will be evaluated and
compared between the three groups using the appropriate statistical tests and analytical
program.