Missile Embolisation Following Shotgun-Inflicted Extremity Trauma
Article Outline
Abstract
Gunshot wounds have the potential to cause harm at a site far removed from the original entry wound through the mechanism of missile embolism. We report a case of shotgun injury to the upper extremity associated with simultaneous embolisation of both the arterial and venous system of the limb with widely different consequences.
Keywords: Shotgun injury, Pellet embolisation, Extremity trauma
Introduction
Shotgun injury to the extremities may cause vascular trauma but intravascular missile embolism is relatively rare. Arterial and venous pellet emboli produce contrasting clinical effects. Thorough assessment aided by appropriate radiographic imaging is the key to successful management.
Case report
A fifteen-year-old boy was brought in as an emergency following an accidental shotgun injury at close range to the lateral aspect of the right upper arm. He was haemodynamically stable on admission. The entry wound site covered an area of 10
sqcm with no obvious exit wound. Examination revealed an ischaemic hand with absent pulses at the wrist despite a good brachial pulse. A hand-held Doppler probe detected triphasic signals over the brachial artery at the elbow and monophasic signals over the arteries at the wrist. No distal neurological deficit was observed. A plain radiograph demonstrated a comminuted proximal humeral fracture with multiple shotgun pellets (3.81mm in diameter) projected over the right shoulder, axilla, upper arm and right side wall of the chest with no intrathoracic injury. CT angiography demonstrated multiple pellets lying inseparable from the axillary artery and proximal brachial artery. The radial artery was patent but small and an embolised pellet was identified in the dominant ulnar artery past which contrast could be seen to flow (Fig. 1).
Figure 1
CT angiogram showing a small calibre radial artery and embolised shotgun pellet in the dominant ulnar artery.
An immediate exploration was performed. The humeral fracture was stabilised by external fixation. The basilic vein was irreparably damaged and ligated. The lacerated brachial artery was successfully repaired using a jump vein graft to revascularise the hand and a fasciotomy was performed. On-table angiography confirmed patency of the brachial, ulnar and radial arteries and revealed distal embolisation of the preoperatively noted intravascular pellet into a digital artery. This was left alone in view of its location and the successful reestablishment of circulation to the hand. Repeat chest radiograph on the following day revealed two pellets, absent on preoperative imaging, projected over the left hemithorax (Fig. 2). In the absence of chest wall trauma the pellets are most likely to have embolised via the venous system of the right arm to the right heart to lodge in the pulmonary vasculature. In the absence of any cardiorespiratory compromise no surgical exploration was considered. Echocardiogram performed with Valsalva manoeuvre ruled out a patent foramen ovale or septal defects. Outpatient follow up at six months demonstrated a fully functional hand with normal pulses and no evidence of further venous embolism.
Figure 2
Plain chest radiograph showing two pellets within the left hemithorax most likely to be in the pulmonary arterial tree.
Discussion
Vascular trauma following shotgun injuries may involve laceration of the vessel wall, pseudoaneurysm, arteriovenous fistula or missile embolism. This report describes a rare case of simultaneous arterial and venous pellet embolism following shotgun-inflicted extremity injury and highlights the potential for such injuries to cause disabling effects far removed from the entry wound. Shotgun pellets are of sufficiently small diameter to embolise along even small arteries and veins. Their kinetic energy is sufficient to penetrate the soft tissues and vessel wall and lodge in the lumen without passing across it completely.1, 2, 3 Arterial and venous missile emboli following extremity trauma produce contrasting clinical effects. The effects of arterial embolism are usually restricted to the injured extremity and apparent soon after the injury. Emergency intervention may be required to prevent limb loss as demonstrated in this patient. Once circulation is restored it is unlikely to pose problems in future. Venous embolism, on the other hand, is unlikely to have a significant effect on the injured limb unless the main venous outflow tract of the limb is completely occluded. It is more likely to produce systemic effects as the missile is carried forward through progressively larger venous channels towards the heart. Its manifestations would depend on the site of final lodgement of the missile and may not be apparent immediately after the injury. Paradoxical embolism across cardiac septal defects has also been reported.4 When dealing with gunshot-inflicted vascular trauma it is important to be aware of the possibility of missile emboli and their potential clinical effects. Conversely evidence of pellet embolism should be considered a sign of major vascular trauma after gunshot injury. Thorough physical assessment and appropriate imaging remains the mainstay of assessment of these patients. Management of pellet emboli requires a selective approach based on site of lodgement of embolus, clinical picture, potential for further embolisation and adequacy of local circulation. Delayed pellet embolisation has also been reported.5 The possibility of missile embolus should be considered in any patient with unexplained clinical features and a prior history of firearm injury with possible missile embolism.
Conflict of Interest
None.
Funding
None.
References
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- . Paradoxical embolism of a shotgun pellet. Ann Thorac Surg. 1998;66:562–564
- . Delayed embolization of a shotgun pellet from the chest to the middle cerebral artery. J Trauma. 1995;39:1006–1009
PII: S1533-3167(09)00019-3
doi:10.1016/j.ejvsextra.2009.04.005
© 2009 Published by Elsevier Inc.
Refers to article:
- Missile Embolisation Following Shotgun-Inflicted Extremity Trauma , 15 June 2009
