Managing oropharyngeal penetrating metallic foreign body into parapharyngeal space in a child: A case report

1. Introduction 

Penetrating oropharyngeal foreign bodies into the parapharyngeal space are rare and their removal challenges the skills of both clinician and the anesthetist. Penetrating oropharyngeal foreign bodies are encountered in children of all ages but commonly seen in the age group of 3–5 years. The most frequent penetrating foreign bodies of oropharynx are long objects with pointed tip like metal sticks, ball point pens, plastic toys, forks, etc. [1]. Common areas of injury in the oropharynx are the area superior to tonsils and the posterior pharyngeal wall.

Foreign body in parapharyngeal area is one of the real emergencies having considerable mortality and morbidity [2]. Due to its close proximity with various vital structures like aero-digestive tract, great vessels, and nerves, any penetrating injury of this region is highly dangerous. Injury to internal carotid artery can present with torrential bleeding, rapidly enlarging hematoma in the neck and neurologic damage. Approximately 10% of these cases can also present with upper airway obstruction and its management tests the skills of even the most experienced anesthetist [3].

We present a case of penetrating oropharyngeal injury by a bow shaped metallic foreign body in a six-year-old child. The foreign body pierced through the retromolar trigone region into the parapharyngeal space. The wound was explored and foreign body removed successfully without any complications. We highlight our experience and difficulties encountered in managing such patients.

2. Case report 

A six-year-old male child presented to our emergency department with history of iron rod protruding from the oral cavity. This incident occurred 2h before, when the child fell from a height (approximately 12ft) on a grilled gate following which a piece of iron rod was stuck in the oral cavity. The rod had injured the upper and lower incisors and got stuck in the retromolar area. The child had history of bleeding from the mouth but there was no active oral bleed at the time of admission. He also had difficulty in opening the mouth. He had no respiratory distress. On physical examination, child was alert and awake and his vital parameters were stable. On examination the mouth opening was restricted and after suctioning the blood clots, we found the end of the rod impacted in the retromolar trigone area, going medial to the angle of mandible and the other end of the rod could be palpated near the mastoid tip. There was no oropharyngeal bulge. The carotid and superficial temporal arterial pulse palpable on the injured side. The superficial temporal arterial pulse on both sides were palpable, equal and was of good volume. There was tenderness over the body of mandible on left side. Immediate tetanus prophylaxis and massive doses of antibiotics were administered.

Lateral neck radiograph showed a well-defined, radio opaque, arrow shaped foreign body extending from the oral cavity region till the mastoid tip traversing the neck. Computed tomography scan showed a radio-dense shadow piercing the retromolar area and entering into the parapharyngeal space. Due to metallic artifacts and scattering effects, great vessels of the neck were obscured by the metallic foreign body. A CT angiogram of the neck was done to find out the relation of the rod to the vessels. However due to the scattering effect of the iron rod the radiologist could not give any conclusive opinion. The rod appeared to lie posterior to great vessels and the great vessels appeared normal above and below the rod Fig. 2.

The patient was taken to the operation theatre for foreign body removal and wound exploration under general anesthesia. We anticipated a difficult intubation and hence experienced anesthetist was consulted. Fibreoptic intubation was considered as back up in case of difficult intubation. More over there was danger of foreign body getting dislodged with danger of catastrophic bleed. Rapid sequence induction and oral intubation was done successfully. During intubation mild pressure was applied over the tip of metallic foreign body to prevent it from dislodging during intubation.

Since we had a limited knowledge regarding the proximity of the vessels to the rod we decided to use cervical transpharyngeal approach with lip split. This approach allowed us a control over the major vessels of the neck and also facilitated head on vision to the foreign body. The rod was stuck in the left retromolar trigone where it had injured the mucosa Fig. 1b and c. The oral wound was explored and the foreign body was held firmly, dislodged slowly and forward force applied to extract the foreign body few millimeters at a time. The procedure was repeated until the impacted foreign body was removed. The foreign body was lying posterior to ICA in the parapharyngeal space. The iron was arrow shaped measuring 9cm×4cm Fig. 3. Betadine irrigation of the wound was done, oral mucosa was sutured using 3.0 vicryl. Hair line fracture of the ramus of the mandible was also noted and since it was undisplaced fracture, a conservative approach was adopted after consulting with oral and maxillofacial surgeon Fig. 1d. After achieving hemostasis, the wound was closed in layers and a corrugated drain was put. A nasogastric tube was also put to facilitate healing of the oral wound.

View Large Image Download to PowerPoint

Fig. 1. (a) Preoperative—showing tip of metallic foreign body in situ at presentation. (b) Intraoperative—showing cervical transpharyngeal approach giving head on view of metallic foreign body. (c and d) Showing hair line fracture of body of mandible.

View Large Image Download to PowerPoint

Fig. 2. (a and b) Plain X-ray showing trajectory of foreign body. (c) Computed tomographic scan of neck-axial view with metallic foreign body. (d) Carotid angiography of neck—showing normal caliber of great vessels above and below the foreign body.

View Large Image Download to PowerPoint

Fig. 3. Removed foreign body.

The patient was put on IV antibiotics and analgesics. Oral feeds were started on the third post-operative day. Sutures were removed on the seventh day and patient discharged. Patient is on regular follow up and is doing fine.

3. Discussion 

Although wide ranging reports and reviews are available on penetrating neck injuries, reports on oropharyngeal foreign body penetrating into the parapharyngeal space of neck with foreign body still in situ, at time of presentation are very rare and management of such conditions is extremely challenging. Extensive literature reviews of penetrating oropharyngeal foreign bodies into the parapharyngeal space are very rare and five cases have been reported till date. The first case report was by Caldwell (1936), described a case of 16-year-old who sustained a oropharyngeal injury by falling onto a hedge with his mouth open. He became drowsy and dysphasic within few hours and hemiplegic after 10h and the child died after 6 days [4]. The second case was reported by Abrol et al. (1972), describing a large foreign body (wooden splinter) of 3cm in diameter, transfixing the neck and was removed successfully without any morbidity [5]. The third case report is by Enomoto et al. (2009) and describes a glass piece entering the space after an accidental blast injury in the laboratory [6] and the fourth report by Bora et al. (2003) describing, a bullet in the parapharyngeal space with an entry wound in the right cheek [7]. There has also been a case reported of a needle entering the parapharyngeal space through the soft palate [1]. All these cases were in adults; we report a unique case of child with metallic foreign body piercing the retromolar trigone area in oral cavity and crossing parapharyngeal space of neck.

Penetrating oropharyngeal injuries must first be evaluated and stabilized by securing airway, controlling active bleed, cervical spine precautions should be followed and addressing any life threatening complications. Most common of injury in the oropharynx is area superior to tonsils and posterior pharyngeal wall. The penetrating oropharyngeal injuries by foreign body into the parapharyngeal space can cause ICA laceration or tear. Common findings in ICA laceration includes rapidly expanding lateral neck hematoma, ipsilateral Horner's syndrome, progressive limb paresis in an alert and oriented patient, a lucid interval with development of neurologic deficit, transient ischaemic attacks. Deep neck abcess, pneumoencephalocele, pseudoaneurysm, and ICA thrombosis have also been reported as complications of orpharyngeal penetrating injuries [8]. Injuries to other structures including injury to tongue, teeth, fracture of mandible, neural and lymphatic structures of neck should be ruled out.

Penetrating oropharyngeal injury with foreign body still in situ may mask the underlying injury by temponade effect and any attempts to remove them in emergency department may lead to catastrophic consequences and should be avoided. Patients may present with respiratory distress at presentation may present with a challenging situation. Attempts at oral intubation may be difficult because of protruding foreign body and also carries risk of dislodging the foreign body leading to catastrophe and further increase the respiratory obstruction. Tracheostomy is a safer option in such cases. Mandatory neck exploration is advised based on hard signs such as rapidly expanding hematoma, pulsatile active bleed, shock unresponsive to fluids, presence of bruit and thrill and diminished distal pulses [9].

If the patient is hemodynamically stable, radiograph can give an idea about the trajectory of metallic foreign body in the neck. CT angiography and color flow Doppler have been considered as safe and effective in the evaluation of penetrating neck injury. However metallic foreign bodies can produce artifacts and can make conclusive opinion difficult on CT angiography, as was seen in our case [10]. Color flow Doppler is a safe and cost effective alternative option [11].

The surgical principal in managing in situ foreign bodies of neck include wide exposure of wound tract and exploration and removal of foreign body, through debridement of the wound, meticulous closure of the pharyngeal wound [12]. In case of suspected great vessel injury, ligature control of the vessels in the neck can prevent massive blood loss during removal of foreign body. Cervical transpharyngeal approach for removing penetrating oropharyngeal foreign body into the parapharyngeal space is safe and can be used in select cases with preoperative suspicion of injury to great vessels of neck.

4. Conclusion 

In conclusion, we have reported our experience with a unique case of an iron rod foreign body lodged in the parapharyngeal space after penetrating through the retromolar trigone. These cases need to be managed cautiously with proper radiology and timely surgical exploration.

Conflict of interest 

There is no conflict of interest or financial disclosure to be made.