Urinary bladder trauma

Last revised by Mohammad Salem Amer on 22 Feb 2024

Urinary bladder trauma describes a spectrum of damage that can be caused to the urinary bladder, usually in the context of significant trauma.

Bladder trauma is generally associated with high energy injuries, and is associated with pelvic fractures in the majority of cases 3,6. The affected demographic therefore closely mirrors those affected by high energy trauma, with young males overrepresented.

The signs of bladder trauma are difficult to define as injuries to the bladder usually occur in the setting of multiple injuries. Hematuria, abdominal pain and difficulty passing urine have been described as a triad of symptoms, but bladder trauma is frequently a radiological rather than clinical diagnosis 7.

Imaging of urinary bladder trauma is indicated when there is external trauma causing pelvic fracture with gross or microscopic hematuria, or widening of pubic symphysis or obturator ring of more than 1 cm on pelvic x-ray 9.

Bladder trauma can be categorized into five types depending on the location and extent of the rupture:

This is commonly seen but not classed as true rupture, since it involves an incomplete mucosa tear. It is equivalent to an intramural hematoma.

Also known as interstitial rupture, this is rare. It is caused by a tear in the serosal surface without a complete tear in the bladder wall.

Occurs in approximately ~15% (range 10-20%) of major bladder injuries, typically resulting from a direct blow to the distended bladder. It typically occurs at the dome of the bladder. It can also result from penetrating trauma, or iatrogenic as a consequence of cystoscopy or surgery. Cystography demonstrates intraperitoneal contrast material around bowel loops, between mesenteric folds and the paracolic gutters. Treatment is surgical repair.

The most common type of bladder injury, accounts for ~85% (range 80-90%) of cases. It is usually the result of pelvic fractures or penetrating trauma. Cystography reveals a variable path of extravasated contrast material. Treatment is with an indwelling urinary catheter.

Simultaneous intraperitoneal and extraperitoneal injury. Cystography usually demonstrates extravasation patterns that are typical for both types of injury.

Traditional investigation for suspected bladder rupture was carried out with fluoroscopic cystography 3. However, as this is time-consuming and cannot characterize other pelvic structures its use is being gradually superseded by CT cystography.

CT cystography is performed by instilling water-soluble contrast into the bladder through a urinary catheter. It may be combined with standard CT to evaluate the upper tracts. An extraluminal position of a urinary catheter indicates bladder rupture, although, in an underfilled bladder, the tip of the catheter may falsely appear extraluminal. Caution should be exercised when catheterizing the patient, in case there is also urethral trauma present.

Appearances vary with the site of injury:

Can remain occult, but intramural hematoma may be visible as a focal thickening of the bladder wall or protrusion into the bladder lumen, without contrast in the wall or outside the bladder 4.

Elliptical layering of contrast within the bladder wall deep to the serosal layer. Contrast remains confined to the bladder wall and lumen 4.

Contrast will be present within the peritoneal cavity, in the paracolic gutters and between small bowel loops. Typically a defect will be visible in the bladder dome 4. Because the contrast has a larger potential space to disperse, contrast appears less concentrated than that seen in extraperitoneal rupture.

Contrast will be present in the extraperitoneal spaces surrounding the bladder, usually streaky as it dissects along fascial planes, and denser than seen in intraperitoneal rupture. The typical location is at bladder base anterolaterally. Extraperitoneal rupture is usually associated with pelvic fractures; the mechanism may be from direct puncture of the bladder wall or shearing forces as the pelvis is fractured 3.

In simple extraperitoneal rupture, contrast is confined to the prevesical space (of Retzius). The molar tooth sign describes the shape of contrast outlining this space around the bladder 8.

Complex extraperitoneal rupture describes extension of extraluminal contrast to the thigh, scrotum or perineum 8.

Will demonstrate mixed features of intraperitoneal and extraperitoneal rupture.

Intraperitoneal rupture requires surgical repair while extraperitoneal injuries may be treated conservatively with a urinary catheter. In cases of bony fragments within the urinary bladder, rectal or vaginal lacerations, or bladder neck injury, immediate repair is needed to prevent fistula formation. Bladder may also be repaired in cases of internal fixation for pelvic fractures to prevent urine contamination of orthopedic hardware 9. The presence of other renal tract injuries involving the ureters or urethra may require separate intervention 9.

ADVERTISEMENT: Supporters see fewer/no ads