Urolithiasis Flashcards
What is the epidaemiology of stones?
Prevalence in general population = 2-3%
Lifetime risk in males 1:8
M:F = 3:1
Peaks:
- Men = 30
- Women = Bimodal at 35 and 50
Chance of stone recurrence is 50% within 10 years (with 10% within a year)
Give the different stone types
Calcium oxalate = 45%
Calcium oxalate + phosphate = 25%
“Triple phosphate” infective = 20%
Calcium phosphate = 3%
Uric acid = 5%
Cystine = 3%
What are the symptoms and signs of stones?
Renal pain (fixed in loin)
Ureteric colic (radiating to groin)
Dysuria / haematuria / testicular or vulval pain
Urinary infection
Loin tenderness
Pyrexia
What are the investigations for stones?
Not imaging
Blood tests - FBC, U+E, Creatinine
Calcium, Albumin, Urate
-Hypercalcaemia should be excluded
Parathormone
Urine analysis and culture
24 hr urine collections
What radiological investigations can you use in stones?
X-ray KUB
-Can show up to 90% of stones
Ultrasound
-May show hydronephrosis
IVU (intravenous urogram)
CT-KUB
- GOLD STANDARD
- Very sensitive
What are the indications for surgical treatment?
Obstruction
Recurrent gross haematuria
Recurrent pain and infection
Progressive loss of kidney function
Patient occupation
What are the techniques for surgical treatment of stones?
Open surgery (now rare)
Endoscopic surgery
ESWL
Open surgery has become far less common with the advent of PCNL and ESWL
What are the advantages and disadvantages of open stone surgery?
Advantage
-Single procedure with least recurrence rate
Disadvantages
- Large scar
- Long hospital stay
- General wound complications
What are the indications for open surgery?
Non functioning infected kidney with large stones necessitating nephrectomy
Cases which for technical reasons cannot be managed by PCNL or ESWL
What is a simple pyelolithotomy?
What is a simple radial nephrotomy?
Small incision made to renal pelvis to remove stone
Having to cut into actual kidney tissue to get to calyx stone
What are the indications for simple partial and total nephrectomy?
Non functioning kidney with large staghorn stones or elderly frail patients with complex stones and normal contralateral kidney.
How common is contralateral stone formation after a total nephrectomy?
Up to 30%
What does PCNL stand for?
Percutaneous Nephrolithotomy
What type of stone gives the characteristic staghorn stone appearance?
Triple phosphate
Staghorn calculi are the result of recurrent infection and are thus more commonly encountered in women
What are the specific indications for PCNL?
Large stone burden (risk of Steinstrasse)
Associated PUJ stenosis
Infundibular stricture
Calyceal diverticulum
Morbid obestity or skeletal deformity
ESWL resistant stones
e.g. Cystine
Lack of availability of ESWL
What is steinstrasse?
“Stone street”
Break up large stone but all the smaller stones black the ureter
Why is infundibular stricture and calyceal diverticuluman indication for PCNL?
Can be treated in the same operation
May remove stone with other options but your not dealing with the underlying problem
How does PCNL work?
Cystoscopy
Guide wire passed up ureter
Retrograde catheter or balloon catheter
Contrast
Guided by ultrasound or X-ray
What are the contraindications for PCNL?
Uncorrected coagulopathy
Active Urinary Tract infection
Obesity or unusual body habitus unsuitable for X-ray tables
-e.g. spinal abnormalities
Relative contraindications include small kidneys and severe perirenal fibrosis
What are the complications of PCNL?
Serious complications in the 3-8% range
Local complications:
-Pseudoaneurysm or AV fistula 0.5-1%
- UT injury:
- –Pelvic tear 8-15%
- –Ureteral tear 5%
- –Stricture of PUJ 0.1-0.8%
Injury to adjacent organs:
- Bowel injury 0.1%
- Pneumothorax 0.1-0.3%
- Liver spleen (very rare)
Systemic complications
- Fever, sepsis 0.2-0.6%
- MI 0.1-0.4%
What is ESWL?
Extracorporeal Shock Wave Lithotripsy
Shock waves crush stones and smaller pieces pass out of body in urine
Newer generation lithotriptors cause less pain
Treatments are usually done on a day-care basis with simple analgesia
Can be repeated as often as required
ESWL is now commonly used for renal and ureteric calculi as first line treatment.
When is it not such a good idea?
Not used as first line treatment for stones >2cms and less effective for lower pole stones
If not effective after 2 treatments then further treatments not justified
Often ineffective for treating cystine stones
What are the indications for open ureterolithotomy?
Not suitable for laparoscopic approach
Failed ESWL or ureteroscopy
What are the indications for ureteroscopy?
Sever obstruction,
Uncontrollable pain
Persistent haematuria
Lack of progression
Failed ESWL and patient occupation
What is the standard instument for treating lower ureteric stones?
Rigid ureteroscope
-90-100% success rate
For proximal stones the success rate is lower at 60-70%
Apart from rigid ureteroscope what other options do you have for endoscopic ureteric stone surgery?
Flexible ureteroscope
Flexible lithoclast
Holmium laser
What are the complications of ureteroscopy?
Minor:
-Haematuria, fever, small ureteric perforation, minor-ureteric reflux
Major:
-Major ureteric perforation, ureteric avulsion, ureteral necrosis and stricture formation
What are the signs and symptoms of bladder stones?
Suprapubic/ groin/ penile pain
Dysuria, frequency, haematuria
Urinary inefction (persistent)
Sudden interuption of urinary stream
Usually secondary to outflow obstruction
How are bladder stones treated?
Most treated endoscopically
Larger stones can be treated by open excision
What percentage of gallstones are radio-opaque (i.e. visible on non-contrast X-ray)?
About 10 %
