URINARY
STONE DISEASE
DEPARTMENT OF UROLOGY IAŞI – 2013
INTRODUCTION


3rd most common condition of the urinary tract (1 – UTIs, 2 –
prostate diseases)
stone recurrence rates – 50% within 5 years !
RENAL & URETERAL





ETIOLOGY
composition = crystals + organic matrix (2-10%)
supersaturated urine  stone formation
 urinary pH
 ionic strength (concentration of monovalent ions)
 solute concentration (concentration of 2 ions, solubility
product, formation product)
 complexation (Na – oxalate, sulfate – Ca)
inhibitors (magnesium, citrate, pyrophosphate, trace metals)
nucleation theory – crystals or foreign bodies immersed in
supersaturated urine
crystal inhibitor theory – absence or low concentration of natural
stone inhibitors
RENAL & URETERAL
nucleation (heterogeneous – epitaxy !), growth & aggregation 
stone formation
 retention in the upper urinary tract (nephrocalcinosis !)
 mass precipitation theory (intranephronic calculosis)
 fixed particle theory – Randall plaques, Carr corpuscles
 matrix calculi – previous kidney surgery & chronic UTIs
STONE VARIETIES
Calcium Calculi (80-85%)
 absorptive hypercalciuria –  Ca absorption   Ca filtered
(glomerulus)   PTH   tubular reabsorption of Ca   Ca ur
 resorptive hypercalciuria – primary hyperparathyroidism
(parathyroid adenoma)   P ur,  P sr   Ca sr,  Ca ur 
renal damage   Ca ur

RENAL & URETERAL
renal hypercalciuria – intrinsic renal tubular defect in calcium
excretion   Ca ur   Ca sr   PTH (secondary)   Ca
resorbtion (bone) & absorption (gut)   Ca ur
 hyperuricosuria
 hyperoxaluria – primary or enteric (inflammatory bowel disease)
 hypocitraturia – metabolic acidosis, hypokalemia (thiazide
therapy), fasting, hypomagnesemia, androgens, UTI
Noncalcium Calculi
 struvite – magnesium, ammonium and phosphate
 uric acid
 cystine – autosomal recessive
 xanthine, indinavir, silicate, triamterene

RENAL & URETERAL
SYMPTOMS & SIGNS AT PRESENTATION
Pain
 renal colic
 noncolicky renal pain
Hematuria
Infection – pyonephrosis, xanthogranulomatous pyelonephritis
Fever, Anuria !, Nausea and Vomiting
EVALUATION
Risk Factors – crystalluria, socioeconomic factors, diet, occupation,
climate, family history, medications
Physical Examination
Imaging Investigations – US, KUB film, IVU, CT (noncontrast spiral),
retrograde pyelography, nuclear scintigraphy
RENAL & URETERAL
Differential Diagnosis – acute appendicitis, ectopic pregnancies,
twisted ovarian cysts, diverticular disease, bowel obstruction,
biliary stones, peptic ulcer disease, acute renal artery embolism,
abdominal aortic aneurysm etc.
INTERVENTION
Conservative Observation – spontaneous passage!
Dissolution Agents – oral alkalinizing agents (sodium or potassium
bicarbonate and potassium citrate), i.v. alkalinization (sodium
lactate), intrarenal alkalinization (sodium bicarbonate)
– acidification – hemiacidrin (Renacidin)
Relief of Obstruction – JJ ureteral stent, PNS
RENAL & URETERAL
ESWL (Extracorporeal Shock Wave Lithotripsy)
 electrohydraulic, piezoceramic, electromagnetic
 approximately 75% of patients with renal calculi (< 1.5-2 cm)
treated with ESWL become stone-free in 3 months
RENAL & URETERAL
Ureteroscopic Stone Extraction
 highly efficacious for lower ureteral
calculi
 stone-free rates range from 66-100%
 lithotrites – electrohydraulic, ultrasonic,
laser, pneumatic
RENAL & URETERAL
Percutaneous Nephrolithotomy
 choice for large (> 2 cm) calculi, those
resistant to ESWL, select lower pole
calyceal stones and instances with
evidence of obstruction
 Remaining calculi can be retrieved
with flexible endoscopes, additional
percutaneous puncture access,
follow-up irrigations, ESWL, or
additional percutaneous sessions
RENAL & URETERAL
Open Stone Surgery
 pyelolithotomy
 anatrophic nephrolithotomy
 radial nephrotomy
 nephrectomy
 ureterolithotomy
BLADDER





manifestation of an underlying pathologic
condition, including voiding dysfunction
(urethral stricture, BPH, bladder neck
contracture, neurogenic bladder) or a
foreign body
irritative voiding symptoms, intermittent
urinary stream, urinary tract infections,
hematuria, or pelvic pain
US
electrohydraulic, ultrasonic, laser,
pneumatic and mechanical lithotrites
cystolithotomy