A shotgun injury to the buttocks; getting to the heart of the matter.

Editor,

CASE

A 19-year-old male presented with a shotgun injury to the buttocks. Entry wounds were visible on both buttocks. There were no other wounds. A pelvic radiograph revealed multiple pellets projected over the right hemi-pelvis (Figure 1). A chest radiograph demonstrated two small foreign bodies in the region of the right heart (Figures 2 and 3). Subsequent computed tomography showed extensive shrapnel in the right transgluteal and perineal regions and two pellets embedded in the right atrium. This embolisation is attributable to entry into the circulation via the pelvic venous system. The patient underwent debridement of the buttock wounds. An echocardiogram excluded a patent foramen ovale. No attempt was made to retrieve the embolised pellets and the patient has remained asymptomatic.

Fig 1

Fig 2

Fig 3

DISCUSSION

Foreign body embolisation is a rare complication of penetrating trauma from firearms. The incidence of bullet embolisation after penetrating injury is estimated to be 0.3-1% (1). Patients may be asymptomatic, however the development of complications such as distal limb ischaemia, endocarditis, pulmonary embolism or stroke should prompt consideration of emboli. The diagnosis of bullet embolisation should also be considered when there is a discrepancy between the number of penetrating wounds and the foreign bodies identified, the location of the bullet does not match that which would be expected by the trajectory or when migration of bullets are demonstrated on serial radiographs.

The most common destination of venous emboli is the right ventricle followed by the pulmonary artery. Embolisation to the right atrium represents less than 5% of the final destination of all such emboli (2). The most common destination of bullet emboli within the arterial system is the femoral artery. The main risk associated with venous emboli is pulmonary embolism, however arterial complications may still occur from right heart emboli if a patent foramen ovale is present. The incidence of patent foramen ovale in the general population is estimated at 25% (3). Emboli in the arterial system are symptomatic in 80% of cases compared to 33% of venous system cases (4).

Foreign bodies that embolise to and remain within the heart have been managed both conservatively and surgically in the literature (5). There may be a role for percutaneous intervention in some cases, however this has not been explored in detail. The presence of complications including endocarditis or arrhythmias may be an indication for intervention. Intra-cardiac emboli may be entrapped within endocardial trabeculations and with time can become encapsulated within fibrous tissue. The long-term risks of endocarditis or mural thrombus formation are not known.

CONCLUSION

Foreign body embolisation should be considered in patients presenting with unexpected symptoms, signs or radiological findings following firearms injury. An echocardiogram should be performed for right heart emboli to exclude a patent foramen ovale due to the risk of arterial embolisation.