UNUSUAL PENETRATING METAL FRAGMENT INJURY TO THE NECK
H.J.Hammawa, S.G. Marshall, E.Ghareeb and W. Holmes
Keyword
Metal fragment, foreign body, bleeding, neck injury.
INTRODUCTION
Penetrating neck injuries pose a diagnostic and therapeutic dilemma to the Accident and Emergency physician as well the trauma surgeon in terms of diagnosis and therapeutic intervention. A thorough knowledge of the anatomy of the neck, physical assessment and recommended available diagnostic adjuvants are necessary for appropriate management. Expeditious decision making is often required to prevent catastrophic sequelae.
The overall mortality of penetrating neck injuries in the three different anatomical areas is at the rate of 9 percent.1 This reflects the difficulties in evaluating the neck in the presence of other associated injuries. In addition, there is lack of consensus among trauma surgeons regarding injuries that mandate surgical exploration and those in which a conservative selective approach can be taken. We report a case in which initial surgical exploration forms part of the essential resuscitative process.
REPORT
A 55 year-old man presented to the Accident and Emergency Department with a history of having sustained an injury to the neck forty minutes earlier. His son said that a piece of flying metal had hit his father’s right lower jaw while he was punching a hole in a steel bar with an industrial drill. Following the injury, he was bleeding profusely from the neck wound and had severe pain.
Rapid primary survey and resuscitation was undertaken. The patient was alert and conscious, his airway was not compromised and his breathing was adequate. There was no evidence of cervical spine injury. The pulse rate was 120/minute, BP was 149/90 mm Hg, respiratory rate was 24/minute and the oxygen saturation was 97% on room air. He had a laceration measuring 6cm x 1cm in the anterior triangle of the right side of his neck which was bleeding profusely. There was also a fullness in that side of the neck and the carotid pulse was palpable. Bleeding was inadequately controlled by digital pressure and further examination in A&E was not possible. It was felt that X-ray of the neck, while desirable, was of secondary importance to urgent stemming of the bleeding, so blood was taken for grouping and cross-matching and the patient was rapidly taken to the operating theatre for neck exploration and control of haemorrhage under general anaesthesia.
Because of the swollen neck, combined with the necessity of heavy pressure on the wound to prevent bleeding, and the fact that the patient was spitting out blood, nasotracheal tubes to intubate nasally prove impossible, although the tubes could pass into the nasopharynx, it could not be advance any further because of obstruction, the nature of which was uncertain. We also felt that oropharyngeal tube would be highly risky, if following administration of muscle relaxant; intubation prove to be difficult or impossible. We decided the safest course of action would be to perform a tracheostomy using the percutaneous technique (Portex).
A submandibular incision was made, and dissection around the submandibular gland and the inner border of the mandible performed. The source of bleeding was found to be the lingual artery deep to the duct. There was also bleeding from a small artery just inferior to the mandible. The bleeding ends of the arteries were isolated and the haemorrhage was controlled effectively by tying them off with 2/0 vicryl sutures. Some residual venous bleeding was controlled with a haemostatic agent (Surgicel). A drain was inserted and the wound was closed in layers. Pharyngeal inspection at the end of surgery, revealed the presence of an enormous lateral wall swelling on the side of injury extending beyond the mid-line. This was obviously the reason why the endotracheal tube could not be passed beyond the nasopharynx.
Following surgery, the patient was stabilised, then a plain X-ray of the neck was done to locate the metal piece in the neck (see x-ray illustration 1, below).
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Illustration 1, X-ray of neck showing the large metal foreign body. |
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At the conclusion of surgery, the patient’s lungs were ventilated for twenty-four hours. There was no further significant bleeding. The neck swelling settled within ten days and two weeks after injury the neck was re-explored to remove the metal fragment. A vertical incision along the anterior border of sternocleidomastoid muscle was made to control the carotid arteries if needed, the anterior jugular vein was ligated, and the muscle was retracted laterally. A large metal fragment shaped like a bullet weighing 43 grams measuring 3cm x 2.5cm with a base diameter of 2cm occupying a large cavity measuring 6cm x 4cm abutting the carotid sheath was found (see picture Illustration 2, below). The cavity was cleaned and a drain inserted. The wound was closed in layers. Post-operatively the patient made a full recovery.
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Illustration 2. Photograph of metal foreign body removed.
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DISCUSSION
The neck is divided into three zones using anatomical landmarks. (Zone I is the horizontal area between the clavicle/suprasternal notch and the cricoid cartilage, encompassing the thoracic outlet structures; Zone II is the area between the cricoid cartilage and the angle of mandible; Zone III is the area that lies between the angle of mandible and base of the skull.) Each of these zones has vital structures that determine how trauma to this area is managed. Penetrating injuries to the neck following assault with knives or bullets are seen commonly. In this case, the injury was due to a flying fragment of metal which hit the mandible and was deflected downwards and laterally in the neck. Similar cases of metal fragment injury have been reported 2,3 but not of this magnitude.
This patient sustained a lower mandibular fracture and penetrating neck injury in anatomic zone II which contains the internal and external carotid arteries, jugular veins, pharynx, larynx, oesophagus, recurrent laryngeal nerve, spinal cord, trachea, thyroid and parathyroid. Injuries to this particular zone are the most frequently occurring, representing about 42% of neck injuries4. Evaluation of patients with penetrating injuries to the neck should always start with the application of Advanced Trauma Life Support (ATLS) principles, a paradigm that begins with a directed primary survey emphasising airways, breathing, and circulation ("ABC"). After the patient is stabilised he can undergo secondary survey that includes the taking of as full a history as possible, and thorough physical examination including relevant investigations, such as X-rays, arteriography, colour duplex and CT scanning, endoscopy and a barium swallow 5,6. This patient presented with life–threatening haemorrhage from the neck wound, so the need to stop the bleeding and stabilise the patient was urgent. The safest and most effective method of dealing with such cases is prompt surgical exploration which has proved to be effective with a mortality rate of about 2% 7.
There is divergence of opinion as regards surgical exploration following penetrating neck injuries without obvious vascular or visceral injury deep to the platysma8,9,10. Some advocate the more conservative policy of observation and extensive investigation that can be very expensive and time-consuming and can over burden available resources, especially in non-trauma dedicated centres; while others would opt for immediate exploration11,12. In this case, prompt surgical exploration was the only viable option.
We present a brief case report of our management strategy, starting with operative exploration to deal with the life threatening haemorrhage followed by a secondary procedure to extract the foreign body two weeks later, having used radiology of the neck to locate and delineate it. A piece of metal of this size should not be left in place because of complications, most notably erosion of the carotid artery, but also compression of the vessel causing narrowing, and late abscess formation.13
SUMMARY
This case demonstrates an unusual traumatic incident in which adherence to the simple ATLS "ABC" teaching has greatly reduced significant mortality. It also shows that immediate neck exploration is an essential part of the initial assessment and resuscitation procedure. The piece of metal removed is the largest foreign body ever reported following penetrating neck injury 12. Non operative management of neck injury should only be done if the patient is stabilised in centres with full investigative and human resources.
REFERENCES