Nephro-urolithiasis

Question 1

What is the chance of stone recurrence within 10 yrs? Within a yr?

Answer 1

50% 10% within a yr

Question 2

What is the commonest cause of urological emergency admission?

Answer 2

Colic

Question 3

What are the types of stones and their relative incidence?

Answer 3

Calcium oxalate = 45%

Calcium oxalate + phosphate = 25%

‘Triple phosphate’ (infective) = 20%

Calcium phosphate = 3%

Uric acid = 5%

Cystine = 3%

Question 4

Give 6 symptoms and signs of a stone

Answer 4

• Renal pain (fixed in loin)
• Ureteric colic (radiating to groin)
• Dysuria/haematuria/testicular or vulval pain
• Urinary infection
• Loin tenderness
• Pyrexia

Question 5

Give 5 non-radiological investigations for stones

Answer 5

• 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

Question 6

What are the radiological investigations for stones?

Answer 6

KUB - kidney, ureter, bladder (shows up the calcium containing stones - over 90% of stones)

USS

IVU - intravenous urogram

CT KUB

Question 7

What are the indications for surgical treatment of stones?

Answer 7

Obstruction

Recurent gross haematuria

Recurrent pain and infection

Progressive loss of kidney function

Patient occupation

Question 8

Give 3 techniques for surgical treatment

Answer 8

• Open surgery (now rare)*
• Endoscopic surgery*
• ESWL*

Question 9

Why has open stone surgery greatly reduced over the past 3 decades?

Answer 9

Tthe advent of PNCL and ESWL

Question 10

Advantage of open stone surgery?

Answer 10

Single procedure with the least recurrence rate

Question 11

Disadvantages of open surgery?

Answer 11

Large scar, long hospital stay, general wound complications, longer recovery

Question 12

Indications for open stone surgery?

Answer 12

• Non-functioning infected kidney with large stones necessitating nephrectomy
• Cases which for technical reasons cannot be managed by PCNL or ESWL

Question 13

2 examples of open stone surgery?

Answer 13

Simple pyelolithotomy

Simple radial nephrotomy

Question 14

When would a simple partial or total nephrectomy be indicated?

Answer 14

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)

Question 15

Indications for PCNL (percutaneous nephrolithotomy)?

Answer 15

• 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

Question 16

Describe the process of PCNL

Answer 16

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

Question 17

Contraindications for PCNL?

Answer 17

• Uncorrected coagulopathy
• Acute UTI
• Obesity or unusual body habitus unsuitable for X-ray tables
• Relative contraindications inc small kidneys and severe perirenal fibrosis

Question 18

2 local complications of PCNL?

Answer 18

Pseudoaneurysm or AV fistula

UT injury: pelvic tear, ureteral tear, stricture of PUJ

Question 19

GIve 3 injuries to adjacent organs which can occur in PCNL (rare)

Answer 19

Bowel injury

Pneumothorax

Liver, spleen (v rare)

Question 20

2 systemic complications of PNCL (rare)?

Answer 20

Fever/sepsis

MI

Question 21

Describe the process of ESWL (extracorporeal shock wave lithotripsy)

Answer 21

Question 22

What is the first line treatment for renal and ureteric calculi?

Answer 22

ESWL

(extra - newer gen lithotriptors cause less pain; treatments done on day-case basis with simple analgesia; can be repeated as often as required)

Question 23

When is ESWL NOT first line treatment?

Answer 23

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

Question 24

Indications for open ureterolithotomy (ureteric stone removal)?

Answer 24

Not suitable for laparoscopic approach

Failed ESWL or ureteroscopy

Question 25

Surgery for ureteric stones

Answer 25

Question 26

Indications for ureteroscopy?

Answer 26

Severe obstruction, uncontrollable pain, persistent haematuria, lack of progression, failed ESWL and patient occupation

Question 27

What is the standard instrument for treating lower ureteric stones?

Answer 27

Rigid uteroscope

(lower ureteric stones = 90-100% success rate; proximal stones = 60-70%)

Question 28

Name the 3 methods of surgery for ureteric/renal stones

Answer 28

• Flexible ureteroscopes
• Flexible lithoclast
• Holmium laser

Question 29

Minor complications of ureteroscopy?

Answer 29

Haematuria

Ffever

Small ureteric perforation

Minor vesico-ureteric reflux

Question 30

Major complications of ureteroscopy?

Answer 30

Major ureteric perforation

Ureteric avulsion

Ureteral necrosis

Stricture formation

Question 31

Presenting features of bladder stones?

Answer 31

• Suprapubic/groin/penile pain
• Dysuria, frequency, haematuria
• Persistent urinary infection
• Sudden interruption of urinary stream

Question 32

What are bladder stones usually secondary to?

Answer 32

Outflow obstruction

Question 33

How are most bladder stones treated?

Answer 33

Endoscopically

Question 34

How are larger bladder stones treated?

Answer 34

By open excision