Diaphragmatic injuries

Diaphragmatic injury is a penetrating or blunt thoracoabdominal and flank injury in which the continuity of the diaphragm is compromised (e.g., via a tear, perforation, or rupture), resulting in herniation of abdominal contents into the thoracic cavity. While diaphragmatic injuries are often asymptomatic, clinical features range from thoracoabdominal pain and decreased breath sounds to acute respiratory distress. Diagnosis is typically based on CT findings, but diagnostic laparoscopy or thoracoscopy may be required if CT scan is normal and there is a high level of clinical suspicion. Most diaphragmatic injuries require operative repair; nonoperative management may be sufficient for selected patients. Delayed complications of diaphragmatic injuries commonly result from diaphragmatic hernias (e.g., bowel obstruction, strangulated hernia).

• Diaphragmatic injury: a penetrating or blunt thoracoabdominal injury in which the continuity of the diaphragm is compromised (e.g., via a tear, perforation, or rupture)
• Diaphragmatic hernia: the protrusion of intra-abdominal contents through a congenital or acquired defect of the diaphragm, into the thoracic cavity

Traumatic diaphragmatic injuries may initially be occult and later present as diaphragmatic hernias, sometimes months to years after the initial injury. ^[1]

Diaphragmatic injuries are rare.

• Incidence among trauma patients: approx 0.5% ^[1]
• Iatrogenic injury: reported after select invasive procedures (e.g., thoracocentesis) and thoracoabdominal surgeries (e.g., hepatectomy, upper abdominal laparoscopic surgery) ^{[2][3] [4][5]}

Epidemiological data refers to the US, unless otherwise specified.

Penetrating injury ^[6][7]

• Epidemiology: 67% of diaphragmatic injuries ^[1]
• Mechanism: direct laceration or puncture of the diaphragm by a penetrating object
• Causes
  • Gunshot wounds
  • Stab injuries
  • Rarely, iatrogenic injury (e.g., thoracoabdominal surgery, thoracentesis, ablative procedures) ^[2][8]
• Characteristics ^[7]
  • Injuries tend to be small (80% are < 2 cm).
  • Often missed on initial evaluation

Blunt abdominal trauma ^[6][7]

• Epidemiology: 33% of diaphragmatic injuries ^[1]
• Mechanism: sudden increase in intra-abdominal pressure causing diaphragmatic rupture
• Causes: motor vehicle collision, falls, crush injuries
• Characteristics
  • Defects are usually large radial tears.
  • Most common on the left side

Other than hiatal hernias, other spontaneously acquired diaphragmatic hernias (e.g., after weightlifting, valsalva maneuver, or childbirth) without a clear history of trauma are very rare. ^[9]

While patients are often symptomatic, symptoms vary based on injury size and the presence of complications (e.g., diaphragmatic hernia).

Acute presentation ^[10]

• Diaphragmatic injury ^[11]
  • Thoracoabdominal pain
  • Thoracoabdominal contusions
  • Referred shoulder pain
  • Decreased breath sounds
• Diaphragmatic hernia ^[11][12]
  • Bowel sounds in the chest
  • Respiratory distress
  • Symptoms of bowel obstruction
  • Symptoms of strangulated hernia (e.g., peritonitis)
• Associated injuries (Isolated diaphragmatic injuries are rare.) ^[7]
  • Signs of penetrating thoracoabdominal and flank trauma
  • Signs of blunt abdominal trauma

Delayed presentation

Delayed symptoms most often result from herniation of abdominal contents through an initially unrecognized diaphragmatic defect, rather than from the injury itself.

• Nonspecific abdominal pain
• Retrosternal pain and pressure
• Cardiopulmonary symptoms (e.g., dyspnea, tachycardia, arrhythmias)
• Complications of diaphragmatic injury

Approach ^[1][7][13]

• Acute presentation
  • Obtain portable chest x-ray and FAST as adjuncts to the primary survey. ^[14]
  • Blunt thoracoabdominal trauma: CT scan for diaphragmatic injury
  • Penetrating thoracoabdominal and flank trauma
    • Right-sided: CT scan for diaphragmatic injury
    • Left-sided: CT scan for diaphragmatic injury or diagnostic laparoscopy
• Delayed presentation: CT scan for diaphragmatic injury

Begin urgent management if indications for emergency exploratory laparotomy are identified during the primary survey.

Chest x-ray

• Poor sensitivity for evaluating diaphragmatic injuries
• Findings ^[15]
  • Abnormal diaphragm contour
  • Elevated hemidiaphragm
  • Bowel in thorax (e.g., air-fluid levels)
  • Nasogastric tube in thorax

Chest x-ray findings of diaphragmatic injury may be misinterpreted as an elevated hemidiaphragm, loculated pneumothorax, or subpulmonic hematoma. ^[7]

CT scan for diaphragmatic injury ^[15]

The choice of CT imaging varies based on suspected concomitant injuries (see "CT scan in trauma") and suspected complications of diaphragmatic injuries (e.g., strangulated hernia).

• Protocols
  • CT chest with IV contrast
  • CT abdomen and pelvis with IV contrast
  • CT chest, abdomen, and pelvis with IV contrast
• Findings
  • Discontinuity of diaphragm
  • Abdominal viscera in thorax
  • Nasogastric tube in thorax
  • Collar sign: band-like constriction of herniated abdominal organs at the level of the diaphragmatic defect

Positive pressure ventilation can temporarily reduce herniated contents, causing diaphragmatic injuries to be missed on imaging. Maintain a high level of suspicion in ventilated patients with thoracoabdominal trauma, even if CT scan is negative. ^[16]

Laparoscopy or thoracoscopy

Laparoscopy or thoracoscopy is used for diagnostic confirmation and therapeutic intervention.

• Indications
  • High clinical suspicion despite negative CT imaging
  • Suspected associated injuries requiring surgical exploration
  • Alternative to CT scan for left thoracoabdominal penetrating trauma
• Findings
  • Discontinuity of diaphragm
  • Abdominal organs in thorax

• Pneumothorax
• Hiatal hernia
• Congenital diaphragmatic hernia
• Phrenic nerve palsy

The differential diagnoses listed here are not exhaustive.

Management of diaphragmatic injuries is guided by hemodynamic stability, the side of the injury (left vs. right), and the mechanism of injury. ^[1]

Approach ^[1]

• Acute presentation
  • Initial management
    • Follow ATLS protocols (see "Management of trauma patients").
    • Identify indications for emergency exploratory laparotomy.
    • Obtain early trauma or surgical consultation for all suspected diaphragmatic injuries.
  • Blunt trauma: operative repair
  • Left-sided penetrating trauma: operative repair
  • Right-sided penetrating trauma: nonoperative or operative repair ^[1]
• Delayed presentation
  • Uncomplicated hernias: elective operative repair
  • Complicated hernias (e.g., strangulated hernia): urgent operative repair with bowel resection if needed

Exercise caution when inserting a chest tube in patients with suspected diaphragm injuries to prevent injuring herniated abdominal contents. ^[7]

Operative management ^[1]

• Surgical approaches
  • Abdominal: (e.g., laparoscopy, laparotomy)
  • Thoracic: (e.g., thoracoscopy, thoracotomy)
• The choice of surgical approach depends on associated injuries.
  • Abdominal approach is preferred over thoracic approach. ^[1]
  • Laparoscopic repair is preferred over open repair for isolated penetrating diaphragmatic injuries. ^[1]

Nonoperative management ^[1]

• May be considered if all of the following criteria are met:
  • Right-sided thoracoabdominal penetrating trauma
  • Patient is hemodynamically stable
  • No diaphragmatic hernia
  • No peritonitis
• Management typically includes:
  • Monitoring (e.g., vital signs, serial abdominal examinations)
  • Supportive care (e.g., antiemetics, analgesia)
  • Outpatient surgical follow-up

Acute complications ^[7]

• Respiratory compromise
• Hemothorax
• Cardiac tamponade ^[17]
• Diaphragm paralysis

Delayed complications

• Herniation with visceral complications, e.g.:
  • Bowel obstruction
  • Bowel perforation
  • Strangulated hernia
  • Gastric volvulus
• Progressive enlargement of the defect

We list the most important complications. The selection is not exhaustive.