Urolithiasis - Kidney stones

Question 1

What is urolithiasis?

Answer 1

Urinary tract stones

Question 2

Relative incidence of stones

Answer 2

M:F ratio 3:1

Peak age in men is 30

Question 3

What is the most common cause of urological emergency admission?

Answer 3

Intermittent pain (renal colic) when a stone gets lodged in your urinary tract

Severe

Question 4

Types of kidney stones

Answer 4

Calcium oxalate - 45%

Calcium oxalate + phosphate

Triple phosphate (infective)

Uric acid

Calcium phosphate - 3%

Cystine

Question 5

Symptoms and signs of kidney stones (6)

Answer 5

Renal pain (fixed in loin)

Ureteric colic (radiating
to groin)

Dysuria / haematuria /
testicular or vulval pain

Urinary infection

Loin tenderness

Pyrexia

Question 6

Investigations carried out for stones

Answer 6

Blood tests - FBC, U&E,
Creatinine

Calcium, Albumin, Urate

Parathormone (parathyroid hormone)

Urine analysis and culture

24hr urine collections

Question 7

Which radiological techniques are used to look at stones? (5)

Answer 7

KUB Radiograph - x ray (Kidney/Ureter/Bladder)

USS

IVU (IV urogram)

CT KUB

CT KUB/Urogram - 3D reconstruction

Question 8

Indications for surgical treatment of stones (5)

Answer 8

Obstruction

Recurrent gross haematuria

Recurrent pain and infection

Progressive loss of kidney function

Patient occupation

Question 9

Within urology, what types of stones can you get?

Answer 9

Renal stones
Ureteric stones
Bladder stones

Question 10

What are some surgical techniques? (4)

Answer 10

Open surgery - now very rare

Endoscopic surgery

ESWL - Extracorporeal shock wave lithotripsy - shocks the stones into smaller pieces - common

Percutaneous nephrolithotomy - PCNL - keyhole surgery

Question 11

Indications for open surgery for stone treatment?

Answer 11

Non-functioning infected kidney with large stones necessitating nephrectomy

Cases which cannot be managed by PCNL or ESWL

Question 12

Indications for Percutaneous nephrolithotomy

Answer 12

Large stone burden (risk of Steinstrasse)

Associated PUJ stenosis.

Infundibular stricture.

Calyceal diverticulum - a urine containing outpouching of a calyx into the renal parenchyma

Morbid obesity or skeletal deformity.

ESWL resistant stones e.g. Cystine or lack of availability of ESWL.

Question 13

How is PCNL carried out?

Answer 13

Guide wire inserted into urinary tract

Retrograde catheter or balloon catheter inserted into the kidney through the ureter

Contrast given

Question 14

Contraindications for PCNL

Answer 14

Uncorrected coagulopathy.

Active UTI.

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

Relative contraindications include small kidneys and severe perirenal fibrosis.

Question 15

Local Complications of PCNL

Answer 15

Pseudoaneurysm or AV fistula

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

Injury to adjacent organs - bowel injury, pneumothorax

Systemic - fever, sepsis, MI (rare)

Question 16

What is first line treatment for renal and ureteric calculi?

Answer 16

Extracorporeal Shock Wave Lithotripsy = ESWL - simple analgesia and can be repeated as often required

Question 17

When is ESWL not used?

Answer 17

If stone is >2cm

It is also less effective for stones in the lower pole (bottom end of the kidney)

Often ineffective for treating cystine stones

Question 18

Indications for Open surgery for ureteric stones

Answer 18

If not suitable for laparoscopic approach.

Failed ESWL or ureteroscopy.

Question 19

Indications for ureteroscopy (endoscopic surgery)

Answer 19

Severe obstruction

Uncontrollable pain

Persistent haematuria

Lack of progression

Failed ESWL

Patient occupation.

Question 20

How successful is ureteroscopy?

Answer 20

The rigid ureteroscope is the standard instrument for treating lower ureteric stones with a 90-100% success rate.

The success rate for proximal stones is lower at 60-70%.

Question 21

Surgical options for ureteric or renal stones?

Answer 21

Flexible ureteroscopes

Flexible lithoclast - combination of ultrasound and pneumatic lithotripsy

Holmium laser

Question 22

Complications of Ureteroscopy: Minor and Major

Answer 22

Minor (0-30%) - haematuria, fever, small ureteric perforation, minor vesico-ureteric reflux

Major - major ureteric perforation, ureteric avulsion, ureteral necrosis and stricture formation

Question 23

What is ureteric avulsion?

Answer 23

Damage to the ureter almost always related to the use of an ureteroscope too large to be readily accommodated by the ureter

Question 24

Presentation 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

Most treated endoscopically

Larger stones can be treated by open excision