Abstract
Ballistic traumas among civilians are usually from low velocity, low calibre weapons such as soft air guns. The facial skeleton is an area of high aesthetic/functional value, and therefore, this is a showcase for technical description of a minimally invasive endoscopic approach for the removal of a bullet from the pterygopalatine fossae.
Keywords: Ballistic trauma, Maxillofacial trauma, Gunshot injury, Pterygopalatine fossa
Introduction
Ballistic trauma of the maxillofacial region includes all injuries sustained by firearms and explosive devices. Gunshot injuries in the maxillofacial area mainly occur in war scenarios, while ballistic traumas among civilians are rare and are usually caused by low velocity, low calibre weapons such as handguns, IED (Improvised Explosive Devices) and soft air guns. These are areas of high aesthetic and functional value; therefore, any surgical approach must consider a proper balance between aesthetic and functional result. Today the minimally invasive endoscopic procedures allow to reach the cranial base through the natural cavities of the facial district, reducing the aesthetic sequelae and maximizing the functional result.
Case Report
We report the case of a 19-year-old guy who came to our attention 15 h after being accidentally hit in the face by a shot from a soft air gun. The bullet entered from the left suborbital region, making a small hole and causing periorbital swelling, without limitation of the ocular motility. The patient complained hypoesthesia of the left hemipalate and anaesthesia of the left upper lip and upper nose (second branch of the left trigeminal nerve, V2).
The CT scans showed a foreign body of presumed metallic nature located posterior to the left maxillary sinus, associated with ipsilateral orbital floor fracture. Clinical evaluation and images analysis suggested the path of the bullet: after entering through the left periorbital tissue the bullet crossed the orbital floor and pierced the posterior wall of the maxillary sinus stopping right into the pterygopalatine fossa, just close to the round foramen and the descending palatine canal. (Fig. 1a, b, c).
Fig. 1.
a, b, c: Pre-operative picture of the patient and CT scan
The patient underwent surgery approximately 72 hours after suffering the trauma; under general anaesthesia, the authors opted for a trans-nasal minimally invasive endoscopic approach. A Hopkins 0 degree rod lens endoscope (Karl Storz) was inserted transnasally. After performing a left maxillary antrotomy, the posterior wall of the maxillary sinus was exposed to locate the bullet. Using angled Vaile forceps the projectile was gently and atraumatically removed from the pterygopalatine fossa without any bleeding.
The surgical exploration of the left orbit floor confirmed no need for treatment. After performing a correct intraoperative haemostasis, the insertion of nasal swabs was not necessary. Two hours after the surgical procedure the patient shows a partial recovery from the dysesthesia in V2 and hemipalate, and after 24 h, the patient was discharged and subjected to a regular clinical follow-up. The clinical examination one month after the surgery has shown a total recovery of the sensitivity in the affected areas, and without any aesthetic and functional sequelae, the CT scan performed at the time showed the complete removal of the bullet. (Fig. 2a, b, c).
Fig. 2.
a, b, c: Post-operative picture of the patient and CT scan
Discussion
Ballistic traumas in the maxillofacial district are rare, and their surgical treatment has always been a challenge for the maxillofacial surgeon due to the high aesthetic and functional value of these areas. The splanchnocranium contains the sense organs, and its integrity is crucial for social interactions.
Several factors take part in determining the extent of injury: the calibre, the mass and the velocity of the bullet striking the target, called the impact velocity.
In conflict-free urban areas, trauma from low-speed, low calibre weaponry prevails [1] and the maxillofacial district is particularly susceptible for these types of trauma, compared to other body areas, due to the bony pneumatisation and to the low degree of soft tissue thickness in this area [2–5].
According to Mark A. Cohen et al. [6], bullets fired from low velocity and low calibre gunshot easily cross the soft facial tissues and thin pneumatized bone structures that absorb most of the kinetic energy. For this reason, the bullets often stop at the base of the skull, where the compact bone is not passed through. This explains why most of the symptoms are related to direct or indirect compression of the neuro-vascular structures that cross the skull base.
In war zones, high-speed injuries prevail which often cause damage with large tissue depletion or even the death. In high velocity, high calibre ballistic trauma, the bullet penetrations fractures and comminute the bone, carrying fragments into the soft tissues, resulting in gross destruction [7].
Xiaoshan Wu et al. [8] reported several cases of transfacial approaches in maxillofacial traumas. These approaches allow direct visualization of the cranial base and open removal of the bullet; however, it has the disadvantages of aesthetic and functional sequelae due to surgical incisions in exposed areas and to the osteotomies needed to gain access to the cranial base.
Today there is a growing focus on minimally invasive approaches in surgery, and the introduction of endoscopic tools in the operating rooms has revolutionized the surgical approaches for the cranial base [9]. Using the angled endoscopic tools, inserted in the natural cavities, the trained endoscopic surgeon gain access to the cranial base preserving the aesthetics and functionality of the face.
To our knowledge, this is the first described case of minimally invasive endoscopic approach to the pterygopalatine fossae for the removal of a soft air bullet. The reported case is particularly interesting for the symptomatology complained by the patient due to the compression, carried out by the bullet, on the trunk of the second branch of the trigeminum nerve just at the emergency of the round foramen. The atraumatic removal of the bullet performed through a trans-nasal endoscopic approach allowed a complete recovery of nerve conduction and total recovery of the sensitivity of the areas.
In conclusion, the reported case suggests that the minimally invasive endoscopic approach for the removal of low-intensity projectiles represents a valuable alternative to the traditional transfacial approaches in the head and neck district. The magnification of the endoscope and the accuracy of the angled instruments allow to perform atraumatic and safe removals preserving the aesthetics and function of the face.
Funding
The authors did not receive support from any organization for the submitted work.
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Declarations
Conflict of interest
The authors have no conflict of interest to declare that are relevant to the content of this article.
Ethical Approval
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Informed Consent
Verbal informed consent was obtained prior to the interview. Patients signed informed consent regarding publishing their data and photographs.
Human Participants and/or Animals
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Patients signed informed consent regarding publishing their data and photographs.
Footnotes
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