Traumatic Abdominal Wall Hernia

Published on 19/07/2015 by admin

Filed under Radiology

Last modified 22/04/2025

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 High-energy injuries: Motor vehicle accidents constitute ∼ 50% of cases, with seat belts increasing risk

– “High-riding” seat belt incorrectly placed over abdomen increases risk (muscle avulsion from iliac crest)
– Other traumatic injuries are common (∼ 80%), with up to 50% of patients suffering other abdominal injuries requiring surgery
image Low-energy injuries (most common in children): Impact by small blunt object (such as bicycle handlebar, i.e., handlebar hernia)

– Hernias can develop after minor trauma in children

CLINICAL ISSUES

• May be overlooked clinically at time of injury and often diagnosed due to hernia-related complications

image Only 22% of patients in 1 series had TAWH diagnosed clinically, making CT essential to diagnosis
image Complications: Incarceration; bowel strangulation, perforation, and ischemia
• Peak incidence in children < 10 years of age due to handlebar injuries

image 2nd most common age group is 20-50 years due to motor vehicle accidents
• Treatment: Delayed repair of hernia usually performed 6-8 weeks following high-energy injuries to allow primary tissue damage to subside
image
(Left) Axial CECT demonstrates small bowel and colon image herniating through a traumatic abdominal wall defect. At surgery, several segments of small bowel had serosal tears and avulsions, requiring resection.

image
(Right) Axial CECT demonstrates a traumatic lumbar hernia, with herniated abdominal fat covered only by the latissimus dorsi muscle image. Also noted is infiltration of the intraabdominal fat image adjacent to the hernia. At surgery, a serosal tear of the descending colon was identified.
image
(Left) Axial CECT demonstrates a large amount of hypoenhancing small bowel image herniated through a traumatic hernia of the right abdominal wall. Active arterial bleeding image is evident. Much of the herniated bowel was not viable at the time of surgery.

image
(Right) Axial CECT shows disruption of the abdominal wall muscles image in the left lower quadrant, with the muscles avulsed from their attachment to the iliac crest. Note the presence of adjacent subcutaneous hematoma image. This is a typical example of a seat belt injury.

TERMINOLOGY

Abbreviations

• Traumatic abdominal wall hernia (TAWH)

Definitions

• Traumatic disruption of musculature and fascia of anterior abdominal wall due to blunt trauma (in absence of penetrating injury) ± herniation of bowel or visceral organs into subcutaneous space
• Handlebar hernia: Localized abdominal wall hernia caused by handlebar (or similar) injury

IMAGING

General Features

• Best diagnostic clue

image Development of new abdominal wall hernia in patient with recent blunt trauma (without penetrating injury)
• Location

image Roughly 75% occur in lower abdomen

– May reflect inherent weakness of lower abdomen due to natural orifices (such as inguinal canals) and susceptibility to increased intraabdominal pressures
image Equally common in right and left sides of abdomen
image Common locations include

– Region of iliac crest in seat belt injury (site of lap and shoulder strap junction)
– Focal hernias often occur in lower abdomen lateral to rectus sheath or inguinal region
– Larger, diffuse abdominal wall defects most often sustained in motor vehicle accidents
– Rarely, hernias may occur through tear in retroperitoneum
• Size

image Anatomical defects vary from small defects (few centimeters) to large disruptions
• Morphology

image Differing patterns of muscular and fascial disruption in each case due to different types of forces involved and tensile properties of various areas in abdominal wall
image All layers of muscle and fascia are usually involved, while skin remains intact

CT Findings

• Best modality to demonstrate size of defect, contents of hernia, and concomitant visceral organ injuries

DIFFERENTIAL DIAGNOSIS

Other Nontraumatic Hernias

• Post-traumatic hernias may have identical appearance to multiple other types of nontraumatic hernias, and key to distinction is clinical history of trauma

PATHOLOGY

General Features

• Etiology

image Most hernias develop due to combination of sudden increase in intraabdominal pressure, direct force of traumatic impact, acceleration-deceleration shear injury, and compressive force of seat belt

– Force is insufficient to penetrate skin but strong enough to disrupt muscle and fascia
image High-energy injuries: ∼ 50% of cases result from motor vehicle accidents, with seat belts increasing risk

– Shearing force applied across bony prominences (e.g., iliac crest)
– “High-riding” seat belt incorrectly placed over abdomen (rather than bony pelvis) increases risk of TAWH (particularly muscle avulsion from iliac crest)

image Obese patients at higher risk for this mechanism
image Low-energy injuries: Impact by small blunt object

– e.g., impaction of bicycle handlebar on abdominal wall (handlebar hernia)
– Hernias can develop after relatively minor trauma in children
image Persistent and severe cough (internal trauma)

– Weak abdominal wall is subjected to stress due to repetitive muscular contractions
• Associated abnormalities

image Other traumatic injuries are common (∼ 80% of cases), with up to 50% of patients suffering other intraabdominal injuries requiring surgery and 1/3 of patients suffering bone injuries

– Bowel, mesenteric, pancreatic, and other visceral injuries are very common

Staging, Grading, & Classification

• Woods et al classification of TAWH types

image Type I: TAWH due to high-energy injuries with common association with other intraabdominal injuries
image Type II: TAWH due to low energy injuries (i.e., handlebar hernia)
image Type III: TAWH due to deceleration injuries with frequent association with internal hernias

CLINICAL ISSUES

Presentation

• Abdominal skin ecchymosis or abrasions (“seat belt” ecchymosis)
• Reducible swelling or cough impulse

Demographics

• Age

image Peak incidence < 10 years due to handlebar injuries
image 2nd most common 20-50 years due to motor vehicle accidents
• Epidemiology

image TAWH uncommon (< 1% of blunt abdominal trauma)

Natural History & Prognosis

• May be overlooked at time of injury due to attention focused on concomitant injuries, and often diagnosed due to development of hernia-related complications

image Only 22% of TAWH patients in 1 series were diagnosed clinically, making CT essential to diagnosis
• Complications: Incarceration, bowel strangulation, bowel perforation, and bowel ischemia

Treatment

• High-energy injuries: Immediate exploratory laparotomy to treat visceral injuries

image Delayed repair of hernia can be performed 6-8 weeks following injury to allow primary tissue damage to subside
image In rare cases, stable patients with only mild intraabdominal injuries may undergo simultaneous repair of hernia during initial exploratory laparotomy
• Low-energy injuries: Surgical options include local exploration, incision overlying defect, laparoscopic repair, and open repair

image Use of mesh now recommended for all TAWH repairs

DIAGNOSTIC CHECKLIST

Consider

• TAWH can be easily missed both on clinical examination and imaging due to presence of concomitant major injuries
• Carefully search for associated intraabdominal injuries
image
Axial CECT shows traumatic avulsion of abdominal wall muscles from a pelvic insertion image.

image
Axial CECT in a patient with a traumatic abdominal wall hernia shows renal laceration and fractured ribs.
image
Axial CECT shows traumatic avulsion of the muscles from the pelvis image.
image
Axial CECT shows pelvic fractures and mesenteric bleeding in a patient with a traumatic abdominal wall hernia.
image
Axial CECT in a 52-year-old man injured in a motor vehicle crash shows the abdominal wall muscles are avulsed from their insertion on the iliac crest, with hemorrhage and herniation of the ascending colon and fat image.
image
Axial CECT in the same patient shows the avulsion of the abdominal muscles from their insertion on the iliac crest, with herniation of the ascending colon image.
image
Axial CECT in a 74-year-old woman involved in a motor vehicle crash shows active extravasation of blood image from mesenteric or retroperitoneal arteries. Several segments of small bowel image show mural hemorrhage, and bleeding is present between bowel loops.

SELECTED REFERENCES

1. Gutteridge, I, et al. Traumatic abdominal wall herniation: case series review and discussion. ANZ J Surg. 2014; 84(3):160–165.

 

Persano, G, et al. Traumatic Abdominal Wall Hernia. Indian J Pediatr. 2014. [ePub].

Griffin, LA, et al. Traumatic abdominal wall hernia from a handlebar injury. Am Surg. 2013; 79(5):E192–E193.

Kulvatunyou, N, et al. Traumatic abdominal wall hernia classification. J Trauma Acute Care Surg. 2013; 75(3):536.

Liasis, L, et al. Traumatic abdominal wall hernia: Is the treatment strategy a real problem? J Trauma Acute Care Surg. 2013; 74(4):1156–1162.

Dennis, RW, et al. Abdominal wall injuries occurring after blunt trauma: incidence and grading system. Am J Surg. 2009; 197(3):413–417.

Netto, FA, et al. Traumatic abdominal wall hernia: epidemiology and clinical implications. J Trauma. 2006; 61(5):1058–1061.

Aguirre, DA, et al. Abdominal wall hernias: imaging features, complications, and diagnostic pitfalls at multi-detector row CT. Radiographics. 2005; 25(6):1501–1520.

Belgers, HJ, et al. Traumatic abdominal wall hernia: delayed presentation in two cases and a review of the literature. Hernia. 2005; 9(4):388–391.

Mahajna, A, et al. Traumatic abdominal hernia associated with large bowel strangulation: case report and review of the literature. Hernia. 2004; 8(1):80–82.

Losanoff, JE, et al. Handlebar hernia: ultrasonography-aided diagnosis. Hernia. 2002; 6(1):36–38.

Vasquez, JC, et al. Traumatic abdominal wall hernia caused by persistent cough. South Med J. 1999; 92(9):907–908.

Damschen, DD, et al. Acute traumatic abdominal hernia: case reports. J Trauma. 1994; 36(2):273–276.

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