Volume 24, Issue 1 , Pages 75-77, January 2003
Unusual primary and secondary facial blast injuries
Article Outline
Abstract
Purpose: To discuss unusual facial injuries resulting from a bomb blast. Materials and Methods: In March 1997, a bomb consisting of a bag of nails was detonated in a coffee shop in Tel Aviv. Two of the wounded were brought to our level 1 Trauma Center with unique facial injuries. Computed tomography (CT) scan and CT angiogram were performed. Results: The blast occurred to the immediate right of the victims who were sitting in an open cafe. Both had tympanic perforation. The first patient showed indirect damage to the facial nerve from a piece of shrapnel located anterior to the carotid artery and medial to the right mandibular angle. The second had a piece of shrapnel lodged in the parapharyngeal space that was initially missed and discovered only on reexamination 3 days later after the patient complained of pain in the temporomandibular joint; there was no facial nerve deficit. The port of entry was probably a small wound in the anterior wall of the external ear canal. Conclusions: The wounds are probably attributable to the spalling effect of the shrapnel passing through the parotid gland, which has mixed-density tissue. These cases show that nerves are susceptible to damage even in the absence of direct engagement and that the emergency room physician should be alert to even small skin imperfections in blast victims to avoid missing penetrating wounds. (Am J Otolaryngol 2003;24:75-77. Copyright 2003, Elsevier Science (USA). All rights reserved.)
(Editorial Comment: The authors show that patients subjected to blast injuries may sustain neural damage even in the absence of direct contact with the nerves.)
The growing use of explosives against the civilian population has raised the number of peacetime blast injuries seen in the emergency department (ED).1, 2, 3 The head and neck area is particularly susceptible because of both its prominent unprotected position and vital contents.2 Primary blast injury to the head and neck is usually manifested as tympanic perforation3, 4 caused by pressure changes in the middle ear.5 The combination of small-size, high velocity of the shrapnel makes secondary penetration injuries potentially dangerous and of great concern to the ED physician because they may lead to sometimes unsuspected structural damage.
Patients and history
On March 23, 1997, a bomb consisting of a bag of nails was detonated in a coffee shop in the center of Tel Aviv, killing 3 people and wounding 30. Two of the wounded, a mother and daughter, were sitting a few meters away from the site of the explosion, with the right side of their bodies facing the blast (Fig 1).
Fig. 1.
Explosion site. The wounded women are sitting with the right side of their bodies facing the explosion.
Case reports
Case 1
The first patient, a 23-year-old woman, complained of pain and discomfort in the right side of the face. Examination of the head and neck area revealed swelling above and around the right parotid gland with good excretion from the Stensen duct. There was a tympanic membrane perforation central on the right and a penetrating wound in the right submandibular region surrounded by superficial lacerations. There were also many superficial lacerations to the back, buttock and right leg and second degree burns on the back and buttock (15% total body surface area). Neurological examination showed partial peripheral facial nerve palsy (mandibular branch).
Computed tomography (CT) scan and CT angiogram showed a piece of shrapnel, 2.0 × 2.5 cm, located anterior to the carotid artery and medial to the right mandibular angle.
At surgery, the neck was explored through an extended parotid excision. The submandibular gland was rotated and through a submandibular approach the infratemporal space was explored and shrapnel removed from within the lateral pterygoid muscle on that side. A hematoma around the shrapnel was evacuated and a drain left in situ. The large vessels were identified and found intact, as were the vagus, hypoglossus, and mandibular branch of the facial nerve. The facial nerve was not explored.
The postoperative period was uneventful, and the patient was discharged 9 days after admission. Complete recovery of the facial nerve was seen 4 weeks after discharge.
Case 2
The second casualty was a 49-year-old woman, who presented with shrapnel wounds, all over her body including the head and neck area. She complained of pain in the right side of the face. Careful examination showed a laceration of the right earlobe, swelling around the right parotid area with no evidence of deficit to facial nerve function on that side, and central perforation of the right tympanic membrane. There were also small superficial shrapnel wounds on the right torso, abdominal wall, right thigh, and ankle. The earlobe was sutured, and the patient was admitted for observation. On the third day of hospitalization, she complained of increased pain and swelling above the right temporomandibular joint and difficulty chewing. Examination showed trismus of 20 mm with local sensitivity exaggerated on lateral movement of the jaw. There was no evidence of facial nerve deficit.
A Water's view radiograph revealed 2-cm shrapnel lateral to the condyle of the right mandible (Fig 2) similar to the one removed from her daughter.
Fig. 2.
Water's view of shrapnel site.
Fig. 3.
CT scan (axial plane). Shrapnel is shown posterolateral to the parotid gland.
Careful reexamination to determine the port of entry of the shrapnel was noncontributory. A small wound in the external canal that went unnoticed in the previous examination was now identified as the possible site of penetration. Response to treatment was good. At 7 days after admission, the pain and trismus were completely alleviated, and the patient was discharged.
Discussion
We describe unique injuries to the facial area in 2 patients exposed to a bomb blast. In addition to tympanic perforation, both had penetrating facial wounds from the high-velocity, upward-directed shrapnel. There were tenderness and swelling over the right parotid gland region (the side facing the explosion), probably a result of the spalling effect of the shrapnel passing through the parotid, a superficial organ with mixed-density tissue.6 The daughter, who was sitting closer to the bomb (Fig 1), also had palsy of the mandibular branch of the facial nerve. Neither the route of the shrapnel nor its final lodging place were closely associated with the route of the nerve. We assume that here, too, the spalling effect, with the possible addition of a thermal effect, explains the damage to the facial nerve.
In the case of the mother, the penetrating wound was initially missed by the attending physician and noted only 3 days later on radiograph after the patient complained of pain in the temporomandibular joint. Reexamination showed evidence of the probable site of penetration in the posteroanterior wall of the external auditory canal. The wound may have been seen on the initial examination but ignored. This case is also interesting because no facial function deficit was observed and because a similar injury in the daughter did indeed cause facial palsy.
These 2 unusual cases show that nerves are susceptible to damage even in the absence of direct or intimate engagement. The lesson to be learned from the second case is that a thorough examination should be performed in every case of blast injury to the head and neck area because even a small skin imperfection can indicate a penetrating shrapnel wound.
References
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- . Tympanic membrane perforation in survivors of a Scud missile explosion. Otolaryngol Head Neck Surg. 1994;110:211–221
- . Blast injuries of the ear in military operations. Ann Otol Rhinol Laryngol Suppl. 1989;140:3–4
- Blast injuries: characteristics of explosion and damage. Harefuah. 1997;132:591–593
PII: S0196-0709(02)32406-2
doi:10.1053/ajot.2003.4
© 2003 Published by Elsevier Inc.
Volume 24, Issue 1 , Pages 75-77, January 2003
