10. Diagnosis of urinary stones; Injuries to the bladder, urethra and male genitalia Flashcards
Urinary stones risk factors
Urinary stones are the most common urological disease
Risk factors:
• Anatomical abnormalities (stasis of urine)
- Genetic factors, normocalcemic hypercalciuria
- Hyperparathyroidism
- Renal tubular acidosis
- Malabsorption (Crohn´s disease)
- Calcium and vitamin D supplements
- Ureter or Kidney malformations due to urinary stasis.
- Crohns disease or malabsorption, decreased fat absorption causes FAs to bind Ca, preventing oxalate absorption, increased oxalate absorption.
- Hypocitraturia.
Urinary stone types
Composition of urinary stones:
- Calcium-oxalate stones: Normally seen in urinary sediment, since they can sometime crystalize in normal pH range.
- Calcium-phosphate stones - Increased pH, alkaline urine
- Ammonium magnesium phosphate - (struvite): Grow in alkaline urine produced by gram negative bacteria with urease enzyme (E.coli), increased pH, alkaline urine.
• Uric acid stones: Seen in acidic urine
• Cysteine stones: Seen in children with autosomal recessive defect of tubular reabsorption of cysteine, and acidic urine.
Transporter defect of Cystine, Ornithine, Lysine, Arginine.
Urinary stone formation
• Step 1: Supersaturation of the content of the stone in the urine
• Step 2: Crystallization:
o Homogenous: Nucleus of stone is made of the same material as the rest of the stone
o Heterogenous: Nucleus can be a blood clot, damaged renal papilla, or foreign body.
- Step 3: Retention of the stone in the urinary system (it doesn’t pass spontaneously with the urine)
- Step 4: Phase of growing
Stones usually form in the renal pelvis.
Urinary bladder stone occur in BPH, neurological patients and permanent catheters.
Urinary stone symptoms
When the stone is in the kidney it is usually asymptomatic.
Renal colic appears when the
stone gets into the ureter, causing strong pain and nausea and vomiting.
Pain radiates to the testicle, labia, and inner thigh.
If the stone gets close to the bladder the patient may feel an urgency, but can only produce a few drops of urine.
If the stone passes to the urinary bladder, all symptoms disappear and the patient will pass the stone.
It rarely will get cuaght in the urethra, typically in the meatus, where it is very painful.
Diagnosing urinary stones
The four cornerstones of basic urological investigation:
- Previous history
- Physical examination
- Ultrasound examination
- Urinalysis
Follow up with an IV-urography. Iodine contrast will be excreted in the kidneys after 10min.
If the urinary tract is normal, all the contrast is seen in the bladder after 20min.
If there is a stone the contrast will stop at the level of the stone (in severe cases the kidney can work slowly on the affected side due to the obstruction, which will require that the pictures are taken later).
Retrograde urography can be done if the non-invasive methods fail.
Types of injuries to the bladder
Bladder lesions are relatively rare due to its position deep within the pelvis. However, a full bladder rise above the pelvic entrance and is more likely to be damaged than an empty one.
Iatrogenic injuries can occur during any pelvic surgery, especially gynecological.
- Blunt bladder injury
- Penetrating bladder injury
- Iatrogenic bladder injury
- Blunt bladder injury:
- Bladder contusion: Injury to mucosa. No treatment necessary.
- Extraperitoneal rupture: The most common type, ~85%, Often due to pelvic fractures or penetrating trauma.
• Intraperitoneal rupture: Typically is the result of a direct blow to the already distended bladder. Due to rise in intravesical pressure (seatbelt). Bowel sounds may be absent due to urinary ascites.
- Symptoms: Bruising, abdominal distensison,
hematuria and lower abdominal pain.
Diagnosis: With CT-cystography
Treatment: Open surgery with closure of the bladder wall.
- Penetrating bladder injury:
External cause of bladder trauma. Always presents with hematuria.
- Iatrogenic bladder injury:
- Urological: During transurethral resection of the bladder
* Gynecological: During hysterectomy, ovarian cyst resection, prolapse surgery and caesarean section.
Trauma to the urethra, types, causes, symptoms, treatment.
Anterior urethral trauma (most common in men) is usually caused by iatrogenic instrumentation.
Non-iatrogenic causes can be from a fall on a bicycle crossbar. This can
cause a urethral stricture, which may become symptomatic 10 years later.
Posterior urethral damage is associated with fracture of the pelvis.
Symptoms:
• Butterfly perineal hematoma
• High-riding prostate on DRE
• Bleeding from meatus with inability to urinate
Diagnosis is done with urethrography.
Treatment: Minor injuries are treated with urethral catheterization for 1 week or longer.
If this fails a suprapubic catheter is placed and surgery is done when the conditions are favorable (endoscopy).
Penile trauma types
Penile fracture - the most common type, due to excessive bending during sexual intercourse.
Amputation - Can be repaired with microsurgery if amputated segment is cleaned and put on ice early enough.
Strangulation - must remove necrotic sections, skin necrosis may still have viable deeper tissues.
Repairing a penis fracture
Injury to the tunica albuginea of the cavernosal bodies and occasionally spongiosal body, with or w/o urthral rupture.
Patients describe a popping sound. The penis deviates to the opposite side of the tunical tear.
Treatment: The fracture must be explored and repaired by absorbable sutures.
The urethra is sutured over a catheter.
Give antibiotics and sustain from sexual intercourse for 6 weeks.
Scrotal trauma
The majority of testicular trauma are due to blunt injury (sports related),
The minority are due to penetrating injuries.
Scrotal hemorrhage and heamtocele are present in most cases.
US is mandatory to assess the integrity of tunica albuginea and blood supply.
Surgical exploration of the testicle is done with tunica albuginea reconstruction and bleeding control.
Give antibiotics.
