Nephro-urolithiasis Flashcards
What is the chance of stone recurrence within 10 yrs? Within a yr?
50% 10% within a yr
What is the commonest cause of urological emergency admission?
Colic
What are the types of stones and their relative incidence?
Calcium oxalate = 45%
Calcium oxalate + phosphate = 25%
‘Triple phosphate’ (infective) = 20%
Calcium phosphate = 3%
Uric acid = 5%
Cystine = 3%
Give 6 symptoms and signs of a stone
- Renal pain (fixed in loin)
- Ureteric colic (radiating to groin)
- Dysuria/haematuria/testicular or vulval pain
- Urinary infection
- Loin tenderness
- Pyrexia
Give 5 non-radiological investigations for stones
- Blood tests - FBC, U+E, Creatinine
- Calcium, albumin, urate
- Parathormone (hyperparathyroidism is number one cause of kidney stones)
- Urine analysis and culture
- 24 hr urine collections
What are the radiological investigations for stones?
KUB - kidney, ureter, bladder (shows up the calcium containing stones - over 90% of stones)
USS
IVU - intravenous urogram
CT KUB
What are the indications for surgical treatment of stones?
Obstruction
Recurent gross haematuria
Recurrent pain and infection
Progressive loss of kidney function
Patient occupation
Give 3 techniques for surgical treatment
- Open surgery (now rare)*
- Endoscopic surgery*
- ESWL*
Why has open stone surgery greatly reduced over the past 3 decades?
Tthe advent of PNCL and ESWL
Advantage of open stone surgery?
Single procedure with the least recurrence rate
Disadvantages of open surgery?
Large scar, long hospital stay, general wound complications, longer recovery
Indications for open stone surgery?
- Non-functioning infected kidney with large stones necessitating nephrectomy
- Cases which for technical reasons cannot be managed by PCNL or ESWL
2 examples of open stone surgery?
Simple pyelolithotomy
Simple radial nephrotomy
When would a simple partial or total nephrectomy be indicated?
Non-functioning kidney with large staghorn stones (upper UT stones that involve renal pelvis and extend into at least 2 calyces) or elderly frail patients with complex stones and normal contralateral kidney
(note: contralateral stone formation in up to 30% after total nephrectomy has been reported)
Indications for PCNL (percutaneous nephrolithotomy)?
- Large stone burden (risk of Steinstrasse)
- Associated PUJ stenosis
- Infundibular stricture
- Calyceal diverticulum
- Morbid obesity or skeletal deformity
- ESWL resistant stones e.g. cystine
- Lack of availability of ESWL
Describe the process of PCNL
With a small 1 centimeter incision in the loin, the percutaneous nephrolithotomy (PCN) needle is passed into the pelvis of the kidney
The position of the needle is confirmed by fluoroscopy (USS or X-ray)
A guide wire is passed through the needle into the pelvis
The needle is then withdrawn with the guide wire still inside the pelvis
Over the guide wire the dilators are passed and a working sheath is introduced
A nephroscope is then passed inside and small stones taken out
Contraindications for PCNL?
- Uncorrected coagulopathy
- Acute UTI
- Obesity or unusual body habitus unsuitable for X-ray tables
- Relative contraindications inc small kidneys and severe perirenal fibrosis
2 local complications of PCNL?
Pseudoaneurysm or AV fistula
UT injury: pelvic tear, ureteral tear, stricture of PUJ
GIve 3 injuries to adjacent organs which can occur in PCNL (rare)
Bowel injury
Pneumothorax
Liver, spleen (v rare)
2 systemic complications of PNCL (rare)?
Fever/sepsis
MI
Describe the process of ESWL (extracorporeal shock wave lithotripsy)
What is the first line treatment for renal and ureteric calculi?
ESWL
(extra - newer gen lithotriptors cause less pain; treatments done on day-case basis with simple analgesia; can be repeated as often as required)
When is ESWL NOT first line treatment?
For stones >2cm
Less effective for lower pole stones
If not effective after 2 treatments then further treatments not justified
Often ineffective for treating cystine stones
Indications for open ureterolithotomy (ureteric stone removal)?
Not suitable for laparoscopic approach
Failed ESWL or ureteroscopy
