Benign Urological Disease

Question 1

What is a renal calculus?

Answer 1

Renal calculus is a stone in the kidneys and ureter that is a common cause of haematuria and typically occurs due to reduced urine output or change in metabolism of calcium, oxolate and cystine where there is increased excretion through the urine.
Citrate is a component in the urine that inhibits stone formation. When this is deficient, this increases the incidence of stone formation.

Question 2

What increases the risk of stone formation?

Answer 2

->Hypercalciuria:
-> Hyperoxaluria:
-> Hyperuricosuria:
-> hypocitraturia:

Question 3

What is the most common types of renal calculus?

Answer 3

The most common type of renal calculus is calcium stones which are associated with hyperthyroidism/hyperparathyoridism and split into calcium isolate and calcium phosphate.

Question 4

What are the features of calcium oxolate stones?

Answer 4

Calcium oxolate stones are the most common types of renal stones formed in acidic urine, increased by:
loop diuretics
Oxolate rich foods like rhubarb and beet
Hyperparathyroidism due to greater calcium
glucocorticoids and Vitamin D supplements.

Question 5

What increases formation of calcium phosphate?

Answer 5

Calcium phosphate stones occur in alkaline urine and are associated with hyperparathyroidism and renal tubular acidosis type 1. Patients are advised to to avoid dairy products due to being rich in phosphate.

Question 6

What are struvite crystals?

Answer 6

Ammonium-magnesium phosphate crystals/struvite occur following a respiratory infection where gram negative bacteria produce urate and result in staghorn coffin-lid like crystals and urine with a strong ammonium smell. Bacteria assoicated with this is pseudomonas, kliebsella and proteus. Staghorn calcium is usually caused by proteus miribalis.

Question 7

What are uric acid stones?

Answer 7

Uric acid crystals is the most common bladder stone that occur due to conditions associated with cell lysis such as cancer, gout or meats where there is a high amount of purines. Thiazide diuretics increase the risk due to dehydration and increase urate reabsorption in the tubules. The crystals are not able to be seen on X-ray so should be imaged with ultrasound.

Question 8

When do cysteine stones form?

Answer 8

Cystine stones occur due to a dysfunction in cysteine metabolism associated with genetic conditions or absorption in the renal tubules.

Question 9

What are the risk factors for nephrolithiasis?

Answer 9

High dietary intake of animal meat protein and low intake of vegetables and fruit
* Urinary acidity due to gout, chronic diarrhoea and metabolic acidosis
* Metabolic syndrome, obesity and diabetes
* Malabsorption syndromes such as Crohn’s disease
* Low urinary volume
* Parathyroid issues
* Cancer- paraneoplastic syndrome
* Gout

Question 10

What is the clinical presentation of kidney stones?

Answer 10

Presentation of stones is pain which is worse on urination, renal colic pain radiating to the groin, with nausea, vomiting, polyuria and haematuria.

Question 11

What prevents formation of kidney stones?

Answer 11

Urinary stones are inhibited from forming by Citrate, water, tamas-horsfall protein and glycosaminoglycans

Question 12

What is the investigation of urinary stones?

Answer 12

Urinalysis using urine dipstick for leukocytes and nitrites and haematuria
Ultrasound to image the kidneys to assess for obstruction, which is ideal for pregnancy and imaging urate stones, however it is not ideal for imaging small stones
FBCs for U&Es for hypercalcaemia and hyperuracaemia and assessing renal disease with creatinine levels
Midstream urine specimen for presence of bacteria, WBCs and RBCs

Question 13

What is the management of urinary stones?

Answer 13

conservative management for smaller stones with fluids, Course of antibiotics for infection, Extracorpereal shockwave therapy to break stones in the kidney and upper ureter, preferred for pregnancy where a
Nephrolithotomy to surgically remove stones too large to pass through, by making an incision on the back to access the kidneys, typically for staghorn calculus.

Question 14

What are the complications of renal stones?

Answer 14

Abscess, renal failure, hydroneephorsis, renal colic and sepsis.

Question 15

What is the treatment of larger urinary stones?

Answer 15

Tamsulosin, an alpha blocker which reduces the smooth muscle contraction of the bladder and prostate to aid in the passage of stones.

Question 16

What is the treatment of kidney stones?

Answer 16

First. Line treatment is lithotripsy, to destroy hardened kidney stones. Second line ureteroscopy is a laser to break up the stones.

Question 17

What is the clinical presentation of a UTI?

Answer 17

Dysuria, haematuria, suprapubic pain and back and flank pain.

Question 18

What is the treatment of UTI?

Answer 18

Treatment for pregnant women for UTI should use oral amoxicillin and nitrofurantoin. THey should avoid the use of trimethoprim due to its teratogenic effect. If it is the 1st and 2nd trimester, nitrofurantoin can be used but 3rd trimester would cause haemolytic disease of the newborn. Nitrofurantoin is also contraindicated in patients with CKD.

Question 19

What is neurogenic bladder?

Answer 19

Neurogenic bladder is associated with loss of parasympathetic sensory innervation, resulting in majority of input from the pudendal nerves causing overfilling of the bladder and stretching of the sphincter muscle, with maintained closure of the urinary sphincter.

Question 20

What are the causes of neurogenic bladder?

Answer 20

This can occur due to damage to the peripheral nerves from diabetes, alcoholism, B12 deficiency and nerve damage.
Damage to the CNS from B12 deficiency and cauda equine syndrome, where there is damage to the spinal root, causing lower back pain, numbness in the saddle area of S2-S4 and loss of bladder control.

Question 21

What is spastic neurogenic bladder?

Answer 21

Spastic neurogenic bladder occurs due to UMN lesion where there is normal bladder volume but involuntary contractions that causes frequent leakage.

Question 22

What is flaccid neurogenic bladder?

Answer 22

Flaccid neurogenic bladder occurs due to peripheral nerve or spinal cord damage with overflow incontinence, where there is a large bladder volume with absent contractions that causes frequency, nostril, urgency and leakage.

Question 23

What is management of neurogenic bladder?

Answer 23

Neurogenic bladder is managed with anticholinergic medications, Botox to reduce destructor muscle contraction, and electrical stimulation of the sacral nerve.