Case Presentation
An 18-year-old Caucasian boy presented to Middlemore Hospital due to a gunshot injury to his neck. The injury was caused by an air rifle. Despite the injury, his condition remained stable, and his GCS was 15/15. The wound’s entry point was to the right of the neck midline, and doctors found no exit wounds. Initial observations revealed a slight amount of active bleeding, along with subcutaneous emphysema and a moderate hematoma that displaced the trachea to the left. Aside from these findings, the examination didn’t reveal any significant results, and the doctors heard no abnormal sounds.
Investigations
Blood investigations for the patient came back normal, showing no abnormalities and raising no major concerns. Doctors also ordered a computed tomography angiography (CTA) of the patient. This was done on the carotid arteries after intravenous injection of 80 ml of Omnipaque 350. The scan unveiled a metal pellet, approximately 6.57 mm in length, lodged about 1.2 cm behind the midpoint of the right common carotid artery (CCA) and roughly 3.5 cm before the carotid artery split. This was situated in front of the transverse process of the C6 vertebra. The pellet seemed to have passed through the upper right thyroid lobe.
Surgery
Based on the critical situation, doctors initiated immediate medical intervention upon the patient’s arrival at the emergency department. Subsequently, the patient went through urgent neck exploration, Common Carotid Artery (CCA) repair, pellet removal, and wound cleansing in the operating room. The patient was positioned supine under general anesthesia, with the head turned to the left and the upper portion of the table elevated by 20 degrees. Doctors administered a dose of 2 grams of Cefazolin at the start.
Using a duplex scan, doctors carefully examined the right carotid artery, which revealed two discoloured areas in the front and back that confirmed the presence of the pseudoaneurysm. The integrity of the common, internal, and external carotid arteries was also confirmed. They marked the location of the carotid bifurcation and the arterial damage on the skin. Additionally, they assessed the right Great Saphenous Vein (GSV) and marked it for potential grafting. After preparation and draping, they made a 12 cm incision along the anterior border of the sternocleidomastoid muscle.
However, the dissection was complicated by the distorted tissue planes caused by the hematoma. Above the anterior belly of the omohyoid muscle, the doctors exposed the proximal CCA and encircled it with a vessel loop. Similarly, they exposed and encircled the proximal internal and external carotid arteries. To prevent clotting, the patient received 5000 IU of Heparin intravenously. After three minutes of circulation, the doctors explored the CCA below the pseudoaneurysm. Throughout the procedure, the vagus nerve was protected. The CCA was then clamped both distally and proximally using DeBakey clamps.
Post-surgical Care and Hematoma Management
Monitoring the cerebral oximetry parameters for three minutes revealed no deviations from the baseline readings, allowing the procedure to continue without shunting. They accessed the area of injury through the overlying hematoma. The pellet’s trajectory was observed to have been through the front medial wall and exited through the back wall of the carotid artery. Both entry and exit points were sealed by clots, with no active bleeding observed. They removed the clots, revealing wounds approximately 3 mm in size with healthy arterial edges. The artery’s lumen was clearly visible through both wounds, with no clots or foreign objects obstructing it. Adequate inflow and outflow were evident, demonstrating a strong and pulsating flow.
They flushed the artery with heparinized saline, and they repaired the wounds using continuous 6/0 Prolene sutures in a horizontal direction, thus avoiding tension. The doctors also flushed the repairs before finalizing them. Standard sequential unclamping techniques were used to restore circulation to the artery. Two additional 6/0 Prolene rescue sutures were needed to ensure hemostasis. The pellet lodged deeper behind the carotid artery and in front of the transverse process of the 6th vertebra, was successfully removed.
Based on the trajectory of the pellet and the findings during the operation, the likelihood of an injury to the gastrointestinal tract was deemed low.
The surgeons irrigated the neck hematoma with Normal Saline. They made a horizontal incision at the small skin entry wound, explored it, washed it with normal saline, and then closed it. Following that, they inserted a 10 Fr Redivac drain and infused the wound with 0.5% Marcain with adrenaline. The surgery caused minimal blood loss.
Conclusion
The patient regained consciousness in the operating room without any issues. He was transferred to the High Dependency Unit and, the next day, to the surgical ward. He began a regimen of 100 mg of oral Aspirin and continued it for three months. A 10-day course of Augmentin was also completed. The drain was removed on the second day after surgery, and he was discharged the same day. The discharge instructions included recommendations for light work and a follow-up with his family doctor in 10 days for a wound assessment. Six weeks post-surgery, he reported feeling well and ready to resume full work duties.
Duplex ultrasound of his right carotid vessels indicated a slight remaining hypoechoic thickening at the mid-common carotid artery to the carotid bifurcation. Despite having normal thyroid function, he missed a scheduled thyroid ultrasound. At a three-month postoperative review, he had no symptoms. His antiplatelet medication was stopped, and a repeat duplex revealed the complete resolution of the previously noted thickening, displaying strong triphasic flows throughout the carotid artery. As a result, the doctors discharged him without requiring further follow-up.
