Nephro-urolithiasis

Question 1

Which gender is more commonly affected by stones?

Answer 1

Males

M:F ratio of 3:1

Peak age in men is 30

Chance of stone recurrence is 50% within 10 years, 10% within a year

Question 2

What are the types of stones and their incidence?

Answer 2

¨Calcium oxalate 45%

¨Calcium oxalate + phosphate 25%

¨‘Triple phosphate’ (infective) 20%

¨Calcium phosphate 3%

¨Uric acid 5%

¨Cystine 3%

Question 3

What are the symptoms and signs?

Answer 3

Renal pain (fixed in loin)

Ureteric colic (radiating to groin)

Dysuria / haematuria /testicular or vulval pain

Urinary infection

Loin tenderness

Pyrexia

Question 4

What are initial investigations for kidney stones?

Answer 4

Blood tests - FBC, U&E, Creatinine

Calcium, Albumin, Urate

Parathormone

Urine analysis and culture

24hr urine collections

MIght show low citrate - citrate can help prevent crystal formation

Question 5

What are the readiological investigations for stones?

Answer 5

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

U/Sound

IVU - intravenous urogram

CT KUB

Question 6

What are indications for surgial treatment?

Answer 6

Obstruction.

Recurrent gross haematuria.

Recurrent pain and infection.

Progressive loss of kidney function.

Patient occupation.

Question 7

What are the techniques for surgical treatment?

Answer 7

Open Surgery (now rare)

Endoscopic Surgery

ESWL - extra corporeal shockwave therapy

Renal stones

Ureteric stones

Bladder stones

Question 8

What are the advantages and disadvantages of open stone surgery?

Answer 8

The advantage of open surgery is:

Single procedure with the least recurrence rate.

The disadvantages of open surgery are:

arge scar, long hospital stay, general wound complications, longer recovery.

Question 9

What are indications for open surgical stone treatment?

Answer 9

Non-functioning infected kidney with large stones necessitating nehrectomy

Cases which for technical reasons cannot be managed by PCNL or ESWL.

PCNL - Percutaneous Nephrolithotomy

Question 10

When is there a need for simple partial and total nephrectomy?

Answer 10

Non functioning kidney with large staghorn stones 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 11

What are indications for PCNL?

Answer 11

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 12

What are contraindications for PCNL?

Answer 12

Uncorrected coagulopathy.

Active Urinary Tract Infection.

Obesity or unusual body habitus unsuitable for X-ray tables.

Relative contraindications include small kidneys and severe perirenal fibrosis.

Question 13

What are the local complications of PCNL?

Answer 13

Pseudoaneurysm or AV fistula 0.5-1%

UT injury: Pelvic tear 8-15%

Ureteral tear 5%

Stricture of PUJ 0.1-0.8%

Question 14

What injury to adjacent organs can occur as a result of PCNL?

Answer 14

Adjacent organs:

Bowel injury 0.1%

Pneumothorax 0.1 - 0.3%

Liver, Spleen (very rare)

Question 15

What are the systemic complications of PCNL?

Answer 15

Fever, sepsis - 0.2-0.6%

Myocardial infarction - 0.1-0.4%

Question 16

Mechanism of ESWL

Answer 16

Question 17

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

Answer 17

ESWL

¨Treatments are usually done on a on a day-case basis with simple analgesia

Can be repeated as often as required

Question 18

When is ESWL not effective?

Answer 18

Not used as first line treatment for stones > 2cms and less effective for lower pole stones

If not effective after two treatments then further treatments not justified

Often ineffective for treating cystine stones

Question 19

What are the common places for a stone to get lodged?

Answer 19

Question 20

What is IVU?

Answer 20

The IVU is a special diagnostic test that follows the time course of excretion of a radiopaque contrast dye through the kidneys, ureters (the tubes that carry urine from the kidneys to the bladder) and bladder after it is injected into a vein in your arm.

The discovery of X-rays and the use of contrast material in 1906 allowed accurate diagnosis and localisation of ureteric stones.

The introduction of the IVU revolutionised the diagnosis of ureteric stones.

Question 21

Indications for open ureterolithotomy - open surgery for ureteric stones

Answer 21

Not suitable for laparoscopic approach.

Failed ESWL or ureteroscopy.

Question 22

Indications for ureteroscopy (endoscopic surgery)

Answer 22

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

Lower ureteric stones have a higher success rate when compared with proximal stones

Question 23

What are the minor and major complications of ureteroscpy?

Answer 23

Minor complications: 0-30%

Haematuria, fever, small ureteric perforation, minor vesico-ureteric reflux.

Major complications:

Major ureteric perforation, ureteric avulsion, ureteral necrosis and stricture formation.

Question 24

What are the presenting features of bladder stones?

Answer 24

Suprapubic / groin / penile pain

Dysuria, frequency, haematuria

Urinary infection (persistent)

Sudden interruption of urinary stream

Usually secondary to outflow obstruction

Question 25

How are bladder stones usually treated?

Answer 25

Most treated endoscopically

Larger stones can be treated

by open excision