5 % of all stones.
Classification
- Migrant
- 3 – 17 % migrate from upper tract
- Primary
- Associated with nutritional deficiency, often in children
- Decreased urine output (dehydration secondary to poor intake and diarrhoea), pH change and other metabolic abnormalities
- Low dietary phosphate and low animal protein -> hypophosphaturia, promoting calcium oxalate and ammonium acid urate
- Usually boys under 10
- Secondary
- Classically men over 60, associated with lower urinary tract obstruction
- BOO associated with 45 – 80 % of secondary bladder stones
- Foreign bodies
- Catheters (2.2 % long term IDC), mesh, IUDs, stents,
- Urinary stasis or incomplete emptying
- Obstruction – BPH, stricture
- Neurogenic bladder (15 – 30 % neuropaths)
- Urinary diversion
- Classically men over 60, associated with lower urinary tract obstruction
EAU – 42 % calcium based, 33 % magnesium ammonium phosphate, 14 % urate, 10 % mixed
Presentation
- Terminal haematuria (most common)
- Varied LUTS
- Urinary retention
- Bladder pain and spasms (classically terminal pain)
- Recurrent UTIs
- In children – pulling at penis and passage of sand
- Incidental
Work-up
- History – including fitness for GA, co-morbidities, previous surgeries, LUTS, excluding of neuropathy
- Examination including scars, obesity, genitals, DRE
- Urine microscopy and culture, haematuria
- Imaging – CT KUB +/- prone, ultrasound, can often be seen on XR
- Flow rate and PVR
- Consider urodynamics
Management
Cystoscopic management (cystolitholapaxy):
- Safe, usually feasible to remove in one operation.
- No incision. Minimal recovery time.
- Stone punch / lithotrite – risks of bladder injury.
- Holmium laser – can use large fibre with continuous flow (23 fr greenlight sheath) – nephroscope use also well described
- Con – potential urethral injury / stricturing
Percutaneous cystolithotripsy:
- Avoid urethra
- Small risk of ongoing urine leak
- Useful if continent diversion, no urethral access
- Allows bigger scopes and instruments cf. urethra
- Techniques – Amplatz sheath, or 2 x laparoscopic ports with a scope in one and grasper or endocatch bag through the other under vision
Open cystolithotomy:
- Can be done extraperitoneal through Pfannenstiel or lower midline
- Need for catheter (+ ?drain) afterwards
- Useful for very large stones
- Can be done in conjunction with transvesical prostatectomy
- Could be offered lap or robot
ESWL – described for patients with prosthetics in attempt to avoid instrumentation. Needs to be done prone.
Chemolysis – not well described or often done – bladder irrigations with potassium citrate, sodium bicarbonate – time consuming and impractical.
Finding stones within neobladders cystoscopically may be tricky – can use II to help. Mucus may need to be washed out or evacuated.
Men with concomitant bladder outlet obstruction and bladder stone
- Classically an indication for surgical management of BOO
- TURP + removal of bladder stone can be combined in same operation – although risk of infection may be higher
- Alternative is medical management with 5-ARIs