Urological trauma Flashcards
What are the risk factors for renal injuries?
- pre-existing renal abnormalities
- > transplant kidney
- > horseshoe kidney
- > ectopic kidney
- > renal tumor & cyst
- > hydronephrosis
- pediatric kidney
- geriatric population
What are the mechanisms of injury to the kidney?
- blunt trauma (90-95%) -> RTA, falls, contact sports, & assault
- penetrating injuries -> gunshot & stab wounds
- > more severe & less predictable
- > potential for greater parenchymal destruction/multiorgan injuries
What is the pathophysiology of kidney injury?
covered by fat & Gerota’s fascia in the retroperitoneum
- deceleration forces -> renal injury like rupture or thrombosis
- acceleration forces -> collision of kidney into surrounding element (ribs, spine) -> parenchymal injury
How is renal injury graded?
American Association for the Surgery of Trauma (AAST) Classification
LOW GRADE
- I -> subcapsular non expanding hematoma &/or parenchymal contusion
- II -> nonexpanding perirenal hematoma confined to Gerota’s fascia -> renal laceration < or = 1cm depth
- III -> renal laceration > or = 1cm in depth
HIGH GRADE
IV -> renal laceration with urinary extravasation -> renal vascular injury (bleeding confined by perineum/retroperitoneum)
V -> shattered kidney with loss of identifiable renal anatomy -> renal vascular injury (devascularized kidney, avulsion of renal hilum)
What are the clinical features of renal injury?
- pain
- bruising
- hematoma on the affected side
- hematuria
- possible accompanying injuries (rib fractures)
- shock
- ureteral injuries -> palpable flank mass, flank pain, & fever
What is the general approach to genitourinary trauma?
- patient history
- physical examination
- urinalysis
- > macroscopic or microscopic hematuria
- > color of urine doesn’t correlate with severity
- microscopic hematuria after significant nonurethral trauma is common
- blood analysis -> CBC, BUN, creatinine
What imaging techniques should be used to diagnose renal injury?
- CT with IV contrast of abdomen/pelvis -> asses renal injuries or intraabdominal fluid retention
- delayed CT -> if injury to renal pelvis & ureters is suspected
- IV pyelography -> assess for contrast extravasation if delayed CT images are nondiagnostic
- urethrocystography -> if CT is unavailable
How should renal injury be treated?
HEMODYNAMICALLY STABLE PATIENTS WITH MINOR TRAUMA
- keep under observation
- foley catheter placement -> if hematuria &/or oliguria
HEMODYNAMICALLY UNSTABLE PATIENTS
- immediate surgical intervention for other injuries prior to definitive treatment of genitourinary injuries
LOW GRADE RENAL INJURY
- observation & vital sign monitoring with bed rest
- antibiotic prophylaxis
- monitor for hematuria
- angioembolization -> for expanding renal hematomas (grade III)
HIGH GRADE RENAL (stable hemodynamics)
conservative measures
- admission to ICU for supportive care
- close hemodynamic monitoring
- serial lab studies & imaging
- angioembolization for expanding hematomas
- ensure adequate urine flow with double JJ ueteral stent
HIGH GRADE RENAL (unstable hemodynamics)
- emergent exploration with surgical defect repair
- possible nephrectomy to prevent threatening bleeding
how should an uncomplicated ureteral injury be treated?
RETROGRADE (cystoscopic) URETERAL STENT PLACEMENT
in -> contusion/hematoma of ureter
-> ureteral laceration with incomplete transection
how should complicated ureteral injury be treated?
- surgical repair
- ureteral ligation -> delayed reconstruction if repair is not possible during primary surgery due to concomitant injuries
- urinary diversion -> percutaneous nephrostomy, stent placement
caused by
- urinoma
- ureteral laceration with complete transsection
- ureteral avulsion
What are the causes of bladder injuries?
- blunt abdominal trauma -> rupture of bladder dome -> intraperitoneal accumulation of urine -> increased BUN & creatinine
- pelvic bone fractured fragments -> extraperitoneal rupture of anterior anterolateral wall of the bladder -> retropubic urine accumulation
- penetrating trauma
- contusion
- iatrogenic -> transurethral or pelvic surgery
What are the clinical features of bladder injury?
EXTRAPERITONEAL/INTRAPERITONEAL INJURY
- gross hematuria
- inability to void
- pain in lower abdomen
INTRAPERITONEAL INJURY
- peritoneal irritation
- rise in serum creatinine through peritoneal resorption of urinary creatinine
What radiological investigation is used for suspected bladder injury?
Retrograde cystography or retrograde CT cystography
- to assess bladder rupture in patients with gross hematuria or microscopic hematuria & pelvic fracture
- DO NOT perform in severe pelvic vascular injury is suspected
How should bladder injury be managed?
KEEP BLADDER DECOMPRESSED -> minimize bladder wall tension to facilitate healing
NO urethral injury:
- place Foley’s catheter
- irrigate bladder to clear clots
- adequate analgesics
- observe patient
- repeat cystogram -> if normal -> discharge
Extraperitoneal injury without bladder neck involvement
- insertion of transurethral indwelling catheter
- suprapubic urinary diversion
Intraperitoneal injury, extraperitoneal injury involving bladder neck, or associated rectal/vagical injury
- open surgical repair
What are the causes of anterior urethral injuries?
- direct trauma to perineum (direct blow, straddle injury) -> BULBOUS URETHRA most common -> scrotal hematoma
- in conjunction with penile fracture
- iatrogenic (instrumentation of urethra)
What are the causes of posterior urethral injuries?
- significant pelvic fracture (vehicle collision)
- BULBOMEMBRANOUS JUNCTION is commonly injured
What is the difference in findings between anterior & posterior urethral injuries?
ANTERIOR POSTERIOR
- blood at urethral meatus, initial hematuria & difficulty voiding
- scrotal hematoma - high riding prostate
- normal prostate - inability to void despite urge
- perineal tenderness & hematoma - palpable distended bladder
- suprapubic pain
What’s the difference in urine extravasation between anterior & posterior urethral injury?
ANTERIOR POSTERIOR
- superficial perineal space - deep perineal space
(with Buck fascia rupture)
- scrotum - retropubic space
- around penis - around bladder & prostate
- lower abdominal wall
Where is the superficial perineal space located?
between Colle’s fascia & the inferior fascia of the urogenital diaphragm
where is the deep perineal space located?
between the superior & inferior fascia of the urogenital diaphragm
What is the best imaging technique to diagnose urethral injury?
RETROGRADE URETHROGRAM
- first diagnostic step BEFORE catheterization
findings -> contrast extravasation from urethra at point of injury
- if some contrast enters bladder -> partial injury
- if no contrast enters bladder -> complete injury (more likely in posterior urethra)
What is the role of Foley’s catheter in urethral injury?
CONTRAINDICATED -> could worsen injury
- in gross hematuria without clinical signs of injury -> ONE ATTEMPT AT CATHETER PLACEMENT ONLY
- successful catheterization without resistance -> no injury
How is urethral injury managed?
MAINTAIN URINARY CONTINENCE & SEXUAL FUNCTION
- place suprapubic catheter to decompress bladder
ANTERIOR INJURY
- partial -> place Foley catheter -> healing by secondary intention
- penetrating injury -> surgical exploration with debridement & defect repair -> direct anastomosis over a catheter
POSTERIOR INJURY
- endoscopic -> early realignment (within 1 week) + transurethral & percutaneous transvesical approach
- surgical -> suprapubic catheter -> delayed urethroplasty 6-12 weeks after initial injury
What are the early complications of uretheral injury?
- bleeding
- infection, abscess
- urinary extravasation
- urinoma
- renal hypertension
What are the delayed complications of urethral injury?
- bleeding
- hydronephrosis
- calculus formation
- chronic pyelonephritis
- hypertension
- arteriovenous fistula
- urethral STRICTURE
- urinary incontinence
- sexual dysfunction
- loss of function in affected kidney due to hydronephrosis or renal artery stenosis
