Pellet (air gun), is a non-spherical projectile metallic mass designed to be shot from an air gun. Air gun pellets differ from bullet sand shots used in firearms in terms of the pressures encountered: air guns operate at pressures as low as 50 atmospheres, while firearms operate at thousands of atmospheres.
At first sight, air guns and air rifles may appear relatively harmless but they are in fact potentially lethal weapons. They use the expanding force of compressed air (or gas) to propel a projectile mass down a barrel. The projectiles are usually led to pellets or ball bearings. Technological refinements have increased the muzzle velocity and hence the penetrating power of these weapons [1, 2]. Injuries from air weapons can be serious and even fatal [3]. Air weapon injuries commonly involve teenage boys. Most are reported to occur in public places or at home. They are predominantly a result of accidental shooting by a friend, relative, or the victim himself, usually in the absence of adult supervision [4].
Several case reports have highlighted the dangers, focusing on injuries to the eye or brain [5, 6].
Approximately one-third of injuries involve the head or neck. It can result in permanent neurological injuries, including epilepsy, cognitive deficits, hydrocephalus, diplopia, visual field cut and blindness [7].
Air weapon injuries in children should be managed in the same way as any low-velocity gunshot injuries. Subcutaneous pellets are best removed. Urgent specialist referral is indicated for cranial, ocular, chest, abdominal or vascular injuries as they may require emergency surgery. Cardiac injuries may be rapidly fatal. The risk of lead intoxication from a retained air gun pellet is extremely small [8].
Retained cardiac missiles may be found free in a cardiac chamber, in the pericardial space, or partially or completely embedded in the myocardium. The initial evaluation should include chest X-ray, 12 lead ECG, 2-dimensional echocardiography and contrast-enhanced CT. The combination of two-dimensional echocardiography and contrast-enhanced CT allows accurate evaluation of the missile location, the extent of vascular and structural heart injury, and the presence and degree of pericardial effusion.
The pellet might lead to pericardial effusion and cardiac tamponade, valvular injury, intracardiac shunts, conduction defects, and/or pulmonary or systemic embolus. Patients with a missile retained in the pericardium or pericardial space may present with pericarditis. Case reports and studies have suggested that missiles completely embedded in the myocardium or pericardium/pericardial space are well tolerated and relatively safe.
The management of thoracic/cardiac pellet gun injuries should be based on the presentation and stability of the patient and the location of the retained pellet. Expectant, non-operative management may be considered for the stable, asymptomatic patient with intramyocardial or pericardial pellets or bullets. In contrast, intracavitary missiles, missiles with valvular injuries or those partially embedded in the myocardium should be removed to prevent embolization or thrombosis. A low threshold for surgical intervention should be used in symptomatic patients. Careful observation and imaging must contribute to the management decisions for any patient presenting with a cardiac missile. Pericardial effusion might need pericardiocentesis and/or cardiac surgery to prevent cardiac tamponade [9, 10].
There are reports of patients, who required surgical intervention for penetrating injuries to the heart, including window pericardiotomy for hemopericardium, exclusion of the cardiac apex for a traumatic ventricular septal defect, and RV injury leading to pericardial effusion and cardiac tamponade requiring pericardial window [11, 12].
Most of the reported injuries to the heart or chest were treated surgically with surgical removal of the pellet [13].
There is a case report of a 15-year-old boy who sustained air pellet injury to the heart leading to pericardial effusion and tamponade. The bullet was in the right ventricle. The patient was taken to the OR and evacuation of pericardial tamponade was done. After the tamponade was relieved, a trans-oesophageal echocardiogram was performed to locate the bullet, which could not be found in the ventricle. Chest and abdominal radiography confirmed that the bullet had migrated retrogradely down into the inferior vena cava. The chest was closed and the patient was transferred from the operating theatre to the interventional radiology department. Under fluoroscopy, the bullet was pulled down into the right common femoral vein and extracted by venorrhaphy [14].
If the pellet is in the left ventricle, there is a potential for embolization and the pellet should be removed, most probably through surgical exploration [15].
In our case, the patient was taken directly to the cath lab and the pellet was snared successfully with no need for surgical exploration or venorrhaphy. We did not find a report of similar intervention for such cases.
In Saudi Arabia, civilian possession of guns is regulated by law. Most conventional air weapons in the KSA require a license, and children under 14 years are not allowed to use an air weapon if not supervised by a person aged 21 years or more [https://www.gunpolicy.org/firearms/region/saudi-arabia].
