Continuing Education Activity

Bladder injury is broadly divided into extraperitoneal and intraperitoneal injuries. Extraperitoneal bladder injuries generally occur with pelvic fractures, while intraperitoneal bladder injuries occur with high-energy impact to an overdistended bladder. Extraperitoneal bladder injury is managed with an indwelling catheter, while intraperitoneal and complex bladder injuries are definitively repaired. This activity reviews the evaluation and management of traumatic bladder injury and highlights the role of the interprofessional health team in improving the care for patients with this condition.

Objectives:

• Describe the pathophysiology of extraperitoneal and intraperitoneal bladder injury.
• Outline the indications for non-operative and operative management of bladder injury.
• Summarize the imaging findings associated with extraperitoneal and intraperitoneal bladder injury.
• Identify interprofessional team strategies for improving care coordination and outcomes in patients with bladder trauma.

Introduction

Bladder trauma is an uncommon injury that can be caused by a direct blow to a distended bladder, high energy injury which disrupts the pelvis, penetrating, and iatrogenic injuries. Bladder traumas are divided into broad categories of extraperitoneal (EP), intraperitoneal (IP), or combined injuries which guide the management plan. There is limited data regarding morbidity and mortality associated with isolated bladder injuries as patients often present with concurrent injuries. Injuries to the bladder occur in up to 10% of abdominal trauma and may be associated with significant morbidity and mortality (10% to 22%).[1][2]

Etiology

Bladder trauma occurs in the setting of motor vehicle collisions (MVC), work-related instances, and violent crimes, but also can be iatrogenic. Two main mechanisms of blunt bladder injury are high energy blow to the lower abdomen while the bladder is distended, which usually results in an IP injury, and trauma causing pelvic fractures, which usually results in an EP bladder injury. As such, bladder trauma commonly occurs with concomitant orthopedic and abdominopelvic visceral injuries. Researchers found traumatic bladder rupture accounts for 1.6% of blunt abdominopelvic trauma cases.[3] There are challenges associated with consistent results regarding bladder trauma. For example, there is evidence that approximately 85% of bladder injuries result from blunt trauma, while incident rates can account for up to 51% of injuries result from penetrating trauma.[4][5] While the national incidence of penetrating injuries in 2015 was less than 10%, the incidence of bladder injuries resulting from penetrating injuries can be much higher.[4][6] Additionally, other less common etiologies of bladder trauma include iatrogenic injuries most commonly during obstetric, gynecologic, or urologic procedures.

Epidemiology

While extraperitoneal (EP) and intraperitoneal bladder (IP) injuries occur with blunt and penetrating traumas, iatrogenic bladder injuries are well-documented as well. EP bladder injuries account for 60% of bladder traumas, while 30% are intraperitoneal, and 10% are combined.[1] Iatrogenic IP bladder injuries are not uncommon. The bladder is the most frequently injured organ in obstetric/gynecologic procedures such as cesarean section and hysterectomies, with an incidence of 13.8 cases per 1000 procedures.[7]

Pathophysiology

The bladder is located in the anterior pelvis in an adult. The dome is covered by the peritoneum, and the bladder neck is fixed to the pelvis by fascia and ligaments. IP bladder rupture occurs on the dome of the bladder and above the peritoneal reflection, while EP bladder rupture occurs below the peritoneal reflection and on the anterior or lateral aspects of the bladder.

Bladder contusion is a partial thickness tear of the bladder and the formation of a hematoma caused by blunt trauma. Patients with bladder contusion can present with gross hematuria. On cystography, there is no extravasation of contrast. This is usually self-limiting, as it is a relatively benign process.EP bladder rupture is most often caused by rapid deceleration. A combination of shearing force and direct penetration by bony spicules of a fractured pelvis is thought to be the underlying mechanism of EP bladder rupture. Complex EP bladder rupture can cause urine leaks into the thighs, penis, perineum, or the anterior abdominal wall. Researchers found that 85% to 100% of bladder injuries are associated with concomitant pelvic fractures.[5]

IP bladder rupture occurs most commonly on the dome of the bladder as it is the only portion covered by the peritoneum; thus, it is the least protected area of the bladder. Contrary to EP bladder rupture, IP bladder rupture is usually caused by a direct blow to a distended bladder, although it can also be associated with deceleration injuries. Urine drains into the abdomen and is absorbed by the peritoneal cavity, manifesting as elevated blood urea nitrogen and creatinine, electrolyte and metabolic derangements, and decreased urine output. Combined EP and IP bladder rupture are less common, accounting for 5% to 8% of bladder injuries associated with pelvic fractures.[3]

History and Physical

Evaluation of a patient with trauma starts with the primary survey, which consists of the airway, breathing, circulation, disability, and exposure. The secondary survey includes a head-to-toe exam. Findings in the secondary survey may suggest bladder trauma includes pelvic instability, blood at the meatus, significant abdominal and pelvic pain, suprapubic tenderness, high riding prostate, and gross hematuria. An unstable pelvic fracture is associated with a high prevalence of massive internal bleeding into the pelvis and should be stabilized with a pelvic binder before surgical intervention. Peritoneal signs such as rigidity, guarding, and rebound tenderness should raise the suspicion not only for perforated viscus in the abdomen but also intraperitoneal bladder injury. The focused assessment with sonography in trauma (FAST) exam can be used to quickly assess for pericardial, intra-abdominal, and pelvic free fluid; however, FAST exams cannot distinguish between blood and urine. Evaluation of the genitals may reveal blood at the urethral meatus, in which case urethral injury needs to be ruled out before inserting an indwelling catheter. A high riding prostate on a rectal exam is also a concern for urethral injury. Gross hematuria is seen in 67% to 95% of cases and is the most classical symptom associated with bladder trauma.[8]

Evaluation

Basic labs such as complete blood count, metabolic panel, coagulation panel, and urinalysis should be obtained as part of the trauma work-up. Retrograde cystography, either computed tomography (CT) or conventional X-ray, is indicated for hemodynamically stable patients with gross hematuria, blood at the meatus, inability to void, pelvic fracture with microscopic hematuria, or penetrating injury to the pelvis, buttock, or lower abdomen. Conventional X-ray and CT cystography have similar sensitivity and specificity. Intravenous contrast CT scan with a delayed phase is less sensitive and specific than retrograde cystography in detecting bladder trauma.[9] According to the European Association of Urology guidelines for urogenital trauma, CT cystography is preferred over traditional X-ray cystography due to rapid turnover time and convenience. Another advantage of CT cystography over conventional cystography is that it is superior in detecting other intra-abdominal processes and bony fragments within the bladder.[10] Imaging findings associated with EP bladder trauma are extravasation of contrast around the base of the bladder confined to the perivesical space and extravasation into the thighs, penis, perineum, or anterior abdominal wall if the urogenital fascia is violated in a complex injury. In IP bladder trauma, contrast extravasates into the peritoneal cavity, outlining the loops of the bowel and filling paracolic gutters. Methylene blue or indigo carmine helps assess suspected bladder injury or evaluate bladder repair intraoperatively.[9]

Treatment / Management

According to the American urological association (AUA) guidelines for bladder rupture, IP bladder rupture is repaired surgically while uncomplicated EP bladder rupture may be treated with catheter drainage. If a retrograde urethrogram shows urethral injury, a suprapubic catheter is placed either via a percutaneous or an open approach.

Surgical intervention is indicated for IP bladder injury due to the risk of intra-abdominal sepsis. In hemodynamically stable patients with isolated IP bladder injury, diagnostic laparoscopy with repair can be considered. Intramural bladder hematoma is left undisturbed as releasing the tamponade effect can lead to significant hemorrhage. The bladder lumen is inspected, any foreign body is removed, and nonviable tissue is debrided. An indwelling catheter is placed before repair. The bladder is classically repaired in two layers with running absorbable suture. Watertight closure is ensured with irrigation by filling the bladder in a retrograde fashion through a urinary catheter. The bladder can also be filled in a retrograde fashion with methylene blue to identify leaks. A pelvic drain may be also be placed in the perivesical space. The abdominal wall layers and skin are closed. Postoperatively, the patient should be placed on broad-spectrum intravenous antibiotics for 24-hours in cases of penetrating injury. The pelvic drain may be removed if it has low output. The indwelling catheter can be removed after 10 to 14 days, and a cystogram is performed before removal, as described earlier.

Uncomplicated EP bladder injury without urethral injury is managed non-operatively with an indwelling catheter for 10 to 14 days and antibiotic prophylaxis. Before removal of the catheter, a repeat retrograde cystography is performed to ensure healing of the injury. If extravasation continues greater than three months after the traumatic event, the injury should be surgically repaired. Indications for operative management EP bladder injury include concomitant vaginal or rectal injury, foreign body in the bladder wall, or orthopedic repair involving hardware.[11]

Differential Diagnosis

When assessing a patient with bladder trauma following differentials should be kept in mind.

• Penile trauma
• Testicular trauma
• Vaginal trauma
• Urethral trauma
• Pelvic fractures – acetabular, open book, straddle, or pelvic avulsion
• Retroperitoneal hemorrhage
• Renal trauma
• Ureteral trauma

Prognosis

Patients with bladder injuries may also present with a wide variety of concurrent traumatic injuries. A single-center retrospective study at a level I trauma center found a mortality rate of 10.8% among patients with bladder rupture undergoing laparotomy for trauma.[2] Untreated bladder rupture can lead to complications such as peritonitis, severe sepsis, and fistulas. Successful management requires timely evaluation, accurate diagnosis, and proper management based on the location and severity of the rupture. Most patients recover normal bladder function. Severe trauma involving the neck of the bladder, the urethra, or pelvic floor muscles may lead to urinary incontinence that may or may not be amenable to surgery.

Complications

Complications can occur either due to bladder trauma itself or due to surgery for bladder repair. Following complications can occur:

• Urinary incontinence
• Wound dehiscence; drainage from wound site should not be confused with urine leak
• Decreased bladder capacity from over-debridement
• Persistent urinary extravasation
• Hemorrhage can occur with violation of pelvic hemorrhage
• A pelvic abscess can develop from an infected hematoma
• Intraabdominal infection
• Fistula
• Urinary tract infection
• Urinary urgency

Postoperative and Rehabilitation Care

Patients should follow up with their surgeon for a wound check and staple removal seven to ten days post-operatively. Indwelling catheters are typically removed 10 to 14 days after the surgery if there is no leak detected on repeat cytogram, and the patient passes a voiding trial. Eastern association of surgery for trauma (EAST) management of blunt force bladder injuries guideline does not recommend routine follow-up cystography in the absence of signs and symptoms that suggest a urine leak for patients who underwent operative repair for simple EP and IP bladder injury.[11] Follow-up cystography is recommended for patients at high risk for urine leak (e.g., non-operative management of an EP bladder rupture, malnutrition, steroid use).[11] The persistent leak usually resolves with extended catheter drainage.

Consultations

The management of bladder trauma is multidisciplinary teamwork. Following specialties are involved in the management of bladder trauma to improve outcomes.

• Trauma surgery
• Orthopedic surgery
• Urology
• Radiology

Deterrence and Patient Education

As previously discussed, bladder injuries may be the result of blunt (e.g., MVCs, and traffic-related accidents) and penetrating (e.g., gunshot and stab wounds) traumas, with the opportunity for injury prevention to deter bladder injuries from occurring. Though scarce, there is research to support injury prevention programs.[12][13][14][15] There are three different types of injury prevention programs discussed: penetrating injuries related to violent crimes, driving, and alcohol/substance use.[16][12][17][13][14][15]

Penetrating injuries accounted for a small percentage of trauma patients (8.34%) seen at trauma centers based on 2015 data from the American College of Surgeons national trauma data bank annual report. However, researchers found 3.5% of penetrating trauma patients experienced reinjuries; interestingly, 30% of these patients presented to different hospitals.[18] Furthermore, self-inflicted injuries were the highest risk group of reinjured patients (odds ratio 2.66 and p less than 0.05), and the patients who sought care at a different hospital for readmission significantly increased their risk of mortality (odds ratio 1.62 and p less than 0.05).[18] Additionally, evidence supported gun-related injury prevention for urban children; the community experienced a close to 50% decrease in gun-related injuries post-intervention compared to a neighboring community (without injury prevention intervention), which experienced an increase in gun-related injuries.[17]

MVCs are a large source of blunt abdominopelvic injuries seen at trauma centers, which can have a variety of causes. Teens have been identified as a high-risk group for distracted driving. Teens who completed a distracted driving program provided positive feedback; 93% of teens reported the program was comprehensive, 89% reported it was relevant to teen driving issues, and 81% of teens reported texting while driving as the most common injury cause for teens compared to other driving risk factors.[12] 

Alcohol use has been a focus of trauma centers since the 2006 mandate from the American College of Surgeons Committee on trauma for all level I trauma centers to screen for alcohol upon trauma patient admission. There is evidence to support numerous high-risk behaviors of trauma patients who acutely or chronically use alcohol 77% reported high-risk driving, 40% reported violent behaviors, and 19% disclosed suicidal ideation within the past 12-months.[19] While patients may arrive at a trauma center with alcohol or other substances in their system, many times, this is the beginning of multiple conversations required to inspire a patient to change. Researchers found 29% of patients who received a “readiness-to-change” interview reported an absolute willingness to address their alcohol or substance use; upon follow-up, no patients attended an appointment based on the resources they were provided upon discharge.[13] Interestingly, other researchers found that there were no significant differences between two brief motivational interviewing interventions compared to brief advice for trauma patients with a history of alcohol or substance use in the past 30 days; however, all three interventions resulted in a significant reduction in substance use at three, six, and 12-months post-discharge.[15] Proper community education and outreach can lead to a reduction in both MVC and penetrating injuries related to violent crimes.

Pearls and Other Issues

As bladder injuries are relatively uncommon, they can be missed due to inappropriate imaging. A common strategy for performing cystography is to clamp the Foley catheter and allow the bladder to fill passively before a CT scan. This practice is discouraged by the EAST guideline on bladder trauma because the bladder may not reliably distend with variation in urine production.[11] The standard protocol, according to the American College of Radiology, is to actively distend the bladder with 300 to 400 mL of contrast material via the Foley catheter prior to the CT scan.[20] A retrospective study found that only 59% of patients with bladder injuries received appropriate bladder imaging on the initial presentation.[21] Another study at a level I trauma center found that among patients with bladder trauma who underwent standard CT without a cystography component, 13% were misdiagnosed and inappropriately underwent surgical exploration.[22] Therefore, it is important to follow proper imaging protocols with consultation from experts to avoid serious morbidity and mortality of a missed or misdiagnosed bladder injury. In a trauma setting, the primary repair of EP bladder injury while the patient is undergoing an operation for a different indication has been associated with reduced ICU stay, the overall length of stay, and complication rates.[23]

Enhancing Healthcare Team Outcomes

Effective management of trauma patients with bladder injury requires an interprofessional team approach, including trauma surgeons, urologists, radiologists, other specialists such as orthopedic surgeons, and nursing staff. Trauma to the genitourinary system can present with similar signs and symptoms but are managed differently based on the affected organ. Therefore, it is imperative to communicate physical exam findings to the entire team to coordinate patient care. For instance, if a male patient is found to have blood at the meatus, there needs to be clear communication among first responders, providers, and nursing staff to first rule out urethral injury before Foley catheter placement to avoid disrupting the urethra and causing serious morbidity. In addition, proper imaging techniques for cystography should be followed with the guidance of radiologists to avoid misdiagnosing or missing a bladder injury. While simple EP and IP bladder rupture can be managed by trauma surgeons, complex injuries warrant consultation.[24] [Level 3]