CASE 11656 Published on 11.03.2014

Compression rupture of abdominal muscles in a child

Section

Paediatric radiology

Case Type

Clinical Cases

Authors

Rafailidis Vasileios¹, Deligianidou Athina², Rafailidis Dimitrios²

1. Department of Radiology,
General Hospital of Katerini,
Katerini, Greece
2. Department of Radiology,
“Gennimatas” General Hospital of Thessaloniki,
Thessaloniki, Greece
Email:billraf@hotmail.com

Patient

7 years, male

Categories

Area of Interest Abdominal wall ; Imaging Technique Ultrasound-Power Doppler, Ultrasound

Procedure Diagnostic procedure ; Special Focus Trauma ;

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Clinical History

The patient presented to the Emergency Department after a bicycle accident. During the accident, the bicycle handlebars hit the patient’s right iliac region. The patient complained of pain in the affected part of the abdomen.

Imaging Findings

The patient was referred for FAST examination and ultrasound of the right iliac region. FAST examination revealed no free intra-abdominal fluid. Ultrasound of the right iliac region with a linear 5-14 MHz probe revealed a compressive partial rupture of the right lateral abdominal muscles and their aponeuroses. (Fig. 1, 2, 3) There was a blood collection between the ends of the ruptured muscles, which extended through the fasciae to the subcutaneous tissue. (Fig. 2) Doppler techniques revealed that there was no rupture of the major blood vessels or vein thrombosis. Increased blood flow was found at the site of the injury. (Fig. 4) The haematoma was caused by the rupture of small blood vessels found along the macerated muscle fibres. After 3 weeks of conservative treatment, a follow-up ultrasound was performed, which revealed an anechoic fluid collection lying internal to the injured abdominal muscles and hyperechogenic tissue representing the scar. (Fig. 5)

Discussion

The anterolateral abdominal muscles include the rectus abdominis, pyramidalis, external oblique, internal oblique and transversus abdominis. [1] Muscular ruptures involve the abdominal wall only in 2% of the cases. They are divided in two types: extrinsic injuries, including compression and penetrating trauma and intrinsic injuries which comprise elongation, partial and complete rupture (type I, II and III respectively).
Direct abdominal injury caused by blunt objects like bicycle handlebars cause focal lesions and sometimes post-traumatic hernias, especially in weak part of the abdominal wall like the area lateral to the rectus abdominis. These injuries rarely affect intra-abdominal organs. [2]
Immediately after trauma, the muscle fibres and their vasculature are disrupted, causing haemorrhage. When the surrounding fasciae are torn, the blood collection may extend outside the muscular belly. Seven days later, the scar begins to form, consisting of fibrous tissue. [3]
In general, the majority of abdominal wall haematomas affect old patients, particularly those under anticoagulant therapy. Oblique muscles are rarely affected and this type of haematomas is poorly described in the literature. [4]
Imaging of such patients comprises MRI or ultrasound. While MRI is excellent in localizing the injury, it has disadvantages like cost and lack of comfort and dynamic imaging. [5] Contrarily, ultrasound is cost-effective, easy to perform even in the acute setting, repeatable and superior to MRI in spatial resolution, cost, convenience, portability and dynamic assessment of the injured muscles. Ultrasound should be performed using a linear high-frequency probe. Extended field-of-view (eFOV) is an ultrasonographic technique producing images which are easy to understand by the clinicians. Colour or Power Doppler techniques can also be used to assess the vascular supply of the injured muscle. [5] Increased blood flow enables us to detect even minor injuries. [6] One of the limitations of ultrasound is operator dependency. Contrast-enhanced ultrasound seems to be superior to unenhanced method in detecting solid organ traumatic lesions and evaluating the extent of muscular rupture during the early post-injury period. The latter may be difficult in cases with great oedema or intramuscular location of the haematoma. [7, 8] Although CT is important in evaluating trauma patients, it can be omitted for radioprotection purposes in children when FAST examination is negative.
Follow-up examination of these patients is necessary and demonstrates a gradual replacement of the haematoma with echogenic scar tissue, starting from the periphery. Complete recovery of the muscular rupture takes 1-4 months and depends on its location and extent. [9]

Differential Diagnosis List

Rupture of the lateral abdominal wall muscles.

Traumatic muscular rupture

Traumatic muscle contusion

Haematoma formation

Final Diagnosis

Rupture of the lateral abdominal wall muscles.

References

[1] Stranding S. (2005) Grays Anatomy. The anatomical Basis of clinical practice. 39th Ed. Edinburgh: Elsevier, Churchill Livingstone p. 1104-11.

[2] Ganchi PA, Orgill DP. (1996) Autopenetrating hernia: a novel form of traumatic abdominal wall hernia--case report and review of the literature. J Trauma 41:1064-6. (PMID: 8970567)

[3] Bianchi S. Martinoli C (2007) Ultrasound of the Musculosceletal System. Berlin: Springer p 54-8.

[4] Shimodaira M, Kitano T, Kibata M, Shirahata K. (2013) An oblique muscle hematoma as a rare cause of severe abdominal pain: a case report. BMC Res Notes 6:18. (PMID: 23327472)

[5] Lee JC, Mitchell AWM, Healy JC. (2012) Olympic Special Feature. Imaging of muscle injury in the elite athlete. Br J Radiol 85:1173-85.

[6] Guillodo Y, Bouttier R, Saraux A. (2011) Value of sonography combined with clinical assessment to evaluate muscle injury severity in athletes. J Athl Train 46:500-4. (PMID: 22488137)

[7] Valentino M, Serra C, Pavlica P, Barozzi L. (2007) Contrast-enhanced ultrasound for blunt abdominal trauma. Semin Ultrasound CT MR 28:130-40. (PMID: 17432767)

[8] Serafin-Król M, Król R, Jedrzejczyk M, Ziólkowski M, Mlosek R, Jakubowski W, Deszczyński J. (2008) Potential value of contrast-enhanced gray-scale ultrasonography in diagnosis of acute muscle injury--preliminary results. Ortop Traumatol Rehabil 10:131-6. (PMID: 18449123)

[9] Van Holsbeeck MT, Introcaso JH. (2001) Musculoskeletal Ultrasound. 2nd Ed. St. Louis: Mosby p 40.

Case information

URL:	https://www.eurorad.org/case/11656
DOI:	10.1594/EURORAD/CASE.11656
ISSN:	1563-4086

Figure 1

Transverse panoramic grey scale ultrasound of the anterolateral abdominal muscles

The applied force resulted in diffuse injury in the right iliac region (arrow). Note the disruption of the normal muscle fibrillar pattern and external oblique aponeurosis and compare it with the normal side.

This ultrasound image demonstrates the ruptured abdominal muscles along with an hypoechogenic fluid collection with irregular borders, which represents a haematoma. Of note is the rounded edge of the lacerated lateral abdominal muscles (arrows).

Figure 2

Transverse ultrasound over the closed contusion trauma

We can see rupture of the muscles, filled with anechoic haematoma. The haematoma is seen extending through the aponeurosis, to the subcutaneous tissue.

Figure 3

Obliquely oriented extended field-of-view sonogram

Image oriented along the fibres of the abdominal wall muscles few hours after the blunt trauma. An anechoic haematoma is seen within the muscular fibres.

Figure 4

Power Doppler imaging at the site of trauma

The haematoma is seen having irregular borders. There is also a disruption of the superficial aponeurosis. Power Doppler technique revealed increased blood flow at the injury site.

Figure 5

Follow-up examination 3 weeks after the injury

We can see the superficial fascia slightly elevated at the site of trauma. There is also a hyperechogenic scar formed (arrow). Residual haematoma is seen behind the ipsilateral rectus abdominis (asterisk).