Blast injury face: An exemplified review of management.

Facial injuries are extremely common due to increased incidence of vehicular and industrial trauma and warfare injuries. But isolated injury to the face due to low voltage cells exploding is rare. In blast injury, the force can cause massive soft tissue injury, along with injury to facial fractures and damage to adnexa. Facial injury is not life threatening unless associated with other injuries of the skull and airway. The major risks to airway in facial trauma are due to anatomic alteration of patient's airway through bony and soft tissue disruption and increased chances of aspiration. The past several decades have seen a rapid growth in the range of procedures available for reconstructive purposes. However, the essential preliminary management is a must and needs to be structured. The patient, a 10-year-old boy, was joining three pencil batteries in series and twisting the wire with his teeth when one battery exploded causing severe injuries to midface and mandibular region. After stabilization, the patient was taken up for surgery. A cap splint with zygomatic suspension was done for the maxilla, and wiring of residual mandibular segments with lining and skin cover provided by a deltopectoral flap was done. Reconstructive surgeries for reconstruction of the upper lip and maintenance of oral continence were planned for the future. The present case stresses the importance of educating the masses about unsafe handling of low voltage devices, management of airway, massive soft tissue injury, along with facial fractures and damage to adnexa.

INTRODUCTION

Today facial injuries are extremely common due to increased incidence of vehicular trauma, industrial trauma, assault (gunshot and knife), terrorist attacks, and warfare injuries. But isolated injury to the face due to low voltage cells exploding is extremely rare in literature.[12]

Low voltage electrical sources like pencil batteries and car batteries are used commonly in homes for daily use appliances and frequently improvised for domestic lighting, musical instruments, etc., In rural India where electric supply is not available round the clock, use of these low voltage sources is common. Low voltage batteries contain high amount of energy. The low internal resistance of such a battery, when short circuited, permits heavy flow of current. Short circuiting of wires instantaneously vaporizes a miniscule portion of the wire at approximately 2000 K, resulting in a blast in a closed cavity causing sudden rise of intraoral pressure which can lead to extensive damage of circumoral structures.[1] The force of that can cause massive soft tissue injury along with facial fractures and damage to salivary gland, ducts, facial nerve, and adnexa. Facial injury is not often life threatening unless it is associated with other injuries of the skull, airway, and other associated injuries.[34] The major risks to airway in patients of facial trauma are due to alteration of patient's airway anatomy through bony disruption, soft tissue disruption, and increased chances of aspiration pneumonitis.[5]

Accidental blast injuries are common in young children who handle these types of activities without proper precaution and can injure themselves severely, even leading to fatalities. Advances in surgery and emergency medicine have shaped the recent management of facial trauma patients. Current management reflects the evolution of both bony and soft tissue reconstruction principles and techniques. The last several decades have seen a rapid growth in the variety and range of procedures available for head and neck region reconstruction purposes. Limited tissue volume, poor adaptability to complex defects, multiple stages of surgery, and the modest vascular supply of local cutaneous and walking-tube type flaps have limited their use in major defect reconstruction to the final cosmetic stages, in which relatively minor contouring is needed.

REVIEW TYPE

A 10-year-old boy, resident of Bahraich in Uttar Pradesh, India, was joining three commonly available pencil batteries in series and twisting the wire with his teeth when one of the batteries exploded causing severe injuries to his midface and mandibular region [Figure 1]. The patient was in a state of shock and fear with severe bleeding from the oral region and breathlessness. He was immediately rushed to our hospital where he had pulse of 120/min, respiratory rate of 36/min, and blood pressure of 86/60 mm of Hg. Proper primary management of maxillofacial injury may avoid the permanent facial disfigurement and serious functional disturbances.

Figure 1

Preoperative photograph

In our case, due to respiratory distress caused by lack of support to the tongue, an emergency tracheostomy was done under local anesthesia and patient's wounds were cleaned thoroughly and dressed. There was no CSF leak present and he was fully conscious. A Ryles tube was inserted for this patient for feeding purposes. Our patient was investigated after stabilization and all routine blood investigations; CT scan of the head with 3D reconstruction was done [Figure 2]. The patient had loss of maxillary alveolar arch and no teeth present in the upper jaw, with fracture and loss of central segment of the mandible carrying all incisors and canines with exposed bilateral mandibular rami and residual body. Soft tissue injuries included loss of the upper and lower lips, skin of the chin region, partial loss of both alae of nose, and loss of the columella with lacerations in the perioral region and abrasions on the chest and right arm and forearm. Debridement of nonviable tissues and daily dressing was done for a week during which patient was given three blood transfusions.

Figure 2

3D CT scan of patient

After stabilization, the patient was taken up for surgery under general anesthesia. A cap splint with zygomatic suspension was done for the maxilla, wiring of the residual mandibular segments done and for lining as well as skin cover right-sided deltopectoral flap was done. The donor site at the deltopectoral flap site was split skin grafted [Figure 3].

Figure 3

Post fixation and DP flap cover

Patient recovery postoperatively was uneventful and he was started back on Ryles tube feeds on the same evening. The flap was delayed on the 18th postoperative day and detached on the 21st postoperative day [Figure 4]. After healing of the stitch line, the stitches were removed on the 8th postoperative day and cap splint removed after 2 months under general anesthesia. Tracheostomy removal was tried, but the patient had tongue fall and so was unsuccessful in the first attempt. The patient is currently undergoing another trial of weaning of the tracheostomy.

Figure 4

Post flap detachment

Patient at present is on Ryles tube feeds and awaiting further reconstructive surgeries for reconstruction of the upper lip and maintenance of oral continence. He has been discharged and we plan to take him up for further reconstructive procedures after 6 months, allowing for local tissues to recover sufficient strength to bear further surgical procedures, an outline of which has been described.

DISCUSSION

The initial evaluation

Airway management

Discipline is needed when dealing with a severe facial injury to ensure that the ABCs of trauma management are undertaken in the emergency room. The ultimate aim of this process is to ensure that airway is secured, the patient's breathing is stabilized, bleeding is controlled with direct pressure, and the cervical spine is cleared for absence of any damage. Craniofacial injury should be suspected in a patient with any facial injury who has been unconscious or who demonstrates neurological deficit, abnormal reflexes, convulsion, or delirium. Appropriate neurologic or neurosurgical consultation is mandatory in all cases of suspected head injuries.[6] In those cases in which extensive laceration has occurred and larger vessels have been damaged, clamping the bleeding vessel with hemostats may be the only means of controlling bleeding in the emergency setting. This should, however, be done carefully to avoid injuring important nerves and their branches.[6] Sometimes packing with large gauge piece are required to control bleeding, the source of which cannot be located.

For patients with facial trauma undergoing operations, patient safety, functional outcome, and aesthetic result are the issues that plastic surgeons need to think about. Several case reports talk about the intracranial malpositioning of the nasopharyngeal airway or the intracranial migration of Foley catheter and nasogastric tube in facial trauma patients, associated with skull base fractures. Blind nasotracheal intubation and even fiberoptic nasotracheal intubation routes carry risk of complications for the skull base fracture patients. Tracheostomy and submental intubations are the alternative routes for maintaining an airway during surgery. However, these two methods need additional surgical procedures to create the tunnel for tubing. Scarring at the incision site is a drawback, and there are associated complications. Bleeding and tracheal stenosis may occur in tracheotomy patients. The reported incidences of significant complications of tracheotomies are between 5% and 40%, with the agreed risk approximated at 15%. Reported submental intubation complications were superficial wound infection, hemorrhage, salivary fistula, and risk of abscess in the submental tunnel. Bonfils firstly reported the retromolar route in 1983. The retromolar route is a less-invasive procedure in comparison with tracheotomy or submental intubation. An effective alternative is an emergency needle cricothyroidotomy which has an advantage of virtually no scar, but it is contraindicated in growing children and needs special jet ventilators.

After attending to the airway if multisystem trauma is evident, all of the systemic injuries should be evaluated by the appropriate services before moving the patient from the emergency room to the operating room for initial management of the facial wound. An accurate visual evaluation is crucial in shaping the management of the patient. The visual status of the eyes (or remaining eye, if one is obviously nonfunctional) is crucial information to have before the first trip to the operating room. If open intracranial injuries are present, neurosurgical management figures prominently into the planning of the first procedure. Severe facial trauma defects present with a variety of different structural peculiarities that the surgeon needs to explore and understand. The degree of bone and soft tissue destruction and avulsion is an unknown when the surgeon enters the operating room for the first time with a severe trauma patient.

Salivary duct, facial nerve, ear, and eyelid injuries are not life threatening, but cause severe functional impairment to the patient.

Salivary duct injuries

Parotid duct injuries in cases of blast injuries of the midface and oral cavity are relatively unheard of. Even if these structures are damaged, the management includes ligation of the duct or marsupialization of the damaged duct into the oral mucosa, and giving antisecretory agents. This leads to gradual decrease in the size of the gland and amount of secretions.

Facial nerve injury

Injuries of the facial nerve and its branches in cases of blast injury of the face are multilevel injuries with varying degrees of severity involving part of the facial nerve exiting the parotid gland. There are commonly devitalized segments of nerve present which are nonsalvageable. As in these cases primary nerve repair in the acute setting is not advisable, the management includes tagging the nerve ends and definitive repair at a later date using nerve grafts; transfer of muscles such as temporalis and masseter may be used in cases where nerve regeneration does not occur.

Ear injury

Injuries to the pinna in blast injuries of the face commonly involve lacerations or avulsions of the pinna. Any laceration should be repaired as early as possible in the acute setting to prevent the exposed cartilage from getting devitalized. Avulsion injuries, especially those which lead to part of the pinna being devitalized, need individualized management including judicious debridement and secondary reconstruction at a later date by using autologous cartilage or synthetic implants covered by temporalis fascia flap.

Injuries to the eye

Injuries to the eye and surrounding adnexae are relatively common feature of blast injuries involving upper face. Prior to definitive management, ophthalmologist's evaluation of the visual status is mandatory keeping in mind the high incidence of retinal detachment and vitreous hemorrhage. After ophthalmic evaluation, surgical repair of the eyelid is done in three layers, that is, skin, tarsal plate, and the conjunctiva. Any entropion or ectropion resulting as sequelae may be treated later.

Vascular injuries in the facial region

The face is an extremely well-vascularized region with extensive collateralization between the vessels. Due to this, extensive collateralization damage to a single named vessel in the face requires no specific management other than ligation or clipping of the bleeding vessel to ensure hemostasis. Damage to multiple vessels leading to devitalization of entire subunits of the face is uncommon, and in this eventuality, debridement of the devitalized structure and reconstruction using the subunit principle is used.

Wound management

Studies point out the importance of early initial debridement of necrotic tissues from severe facial injuries and the importance of beginning antibiotic treatment as soon as possible. This aspect of facial trauma previously dictated that reconstruction begin with soft tissue closure, despite underlying bone loss. Only after complete soft tissue healing occurred could the underlying bone loss be reconstructed in a sterile wound. The scar contracture that formed during the soft tissue healing in these wounds frequently rendered an optimal final bony and soft tissue repair impossible. With regard to this critically important aspect of facial reconstruction, free tissue transfer has dramatically advanced the management of the severe open facial trauma patient. Once the patient is stabilized and cleared for general anesthetic, the initial operative management should take place as soon as possible. The goals of the initial procedure are to address intracranial injuries, debride all foreign material and obviously nonviable tissue, establish and stabilize occlusal relationships in remaining tooth-bearing segments, and perform satisfactory bony reconstruction to maintain the facial soft tissue envelope. During wound debridement, if there is a question about the viability of tissue, it is retained to declare itself within 24-72 h. This is particularly true of skin margins and the tissues of the nose, palate, lips, and medial canthal areas, where the survival of tissues may significantly influence the choice of flap reconstruction or how a particular flap is used for definitive reconstruction. In most cases, occlusion can be established acutely with maxillomandibular fixation. In cases with significant or palatal or mandibular comminution, the acute fabrication of dental splints may serve to minimize lingual rotation of mandibular segments when maxillomandibular fixation is applied, assist in establishing the horizontal arch dimension, assist in fracture stabilization, and function as a tension band.

Effort should be undertaken at the initial steps to perform enough underlying bone reconstruction to prevent contracture of the facial soft tissues.

This goal is addressed at the initial procedure in several ways:

Definitive bone grafting in all areas with adequate soft tissue coverage

Temporary bone grafting in areas with unsatisfactory soft tissue coverage for interim stenting of the surrounding soft tissues

Locking reconstruction plate fixation of segmental mandibular defects with anticipated definitive bone reconstruction during future surgery.

Significant systemic injuries that potentially hinder return to the operating room for future surgery should be managed as quickly as possible during this period. Finally, the provision of both psychiatric and social service consultation should be undertaken as necessary.

This critical initial phase of managing a patient has been summarized in Table 1.

Table 1

The initial management of blast face victims

Definitive reconstruction

Once the patient has been resuscitated, a thorough evaluation of the actual tissue deficit as done. This is done by a thorough clinical examination and confirmed by radiology. A 3D reconstruction CT scan happens to be of an immense value in this assessment. Exact bony and soft tissue deficit is measured and an attempt is made to replace like with like. Priority, however, in this stage lies upon providing tissue cover to the wounds which are unlikely to heal, or are likely to heal with residual deformities. Any exposed bone is provided a flap cover. If possible, first priority is always to be given to local tissues. If local options are not available or fall short, then a choice has to be made between a regional and a free flap cover.

The available options for definitive reconstruction are tabulated in Table 2.

Table 2

The definitive phase of reconstruction

Secondary improvement in function and cosmesis

This stage is the final remodeling stage and involves rehabilitating the patient for general acceptance in the society. The primary concern of this phase is usually debulking and “shaping” excess soft tissue. The first debulking procedure can be performed as early as 6 weeks following the initial flap procedure. This allows enough time roughly gauging how much viable vascularized adipose tissue remains. If the flap has been performed for maxillary or mandibular reconstruction, the debulking often centers on commisuroplasties in conjunction with dental rehabilitation. If osseointegrated implants are to be placed, this is done at the time of the commisuroplasty. Both tissue-borne dentures and osseointegrated implants require a soft tissue cover over the bone, which is thin and immobile. If a skin paddle has been used to cover bone intraorally, some form of debulking is often required. If additional vestibular depth and satisfactory implant-bearing surface area is required, commisuroplasties are performed. When adequate soft tissue contour is not attained with the first debulking procedure, additional debulking is performed.

If a flap has been used for external soft tissue replacement, the debulking should be done very conservatively, waiting up to 6 months before the second debulking. Cutaneous skin paddles continue to lose bulk over 1 year after placement, and some skin paddle contracture also continues over this long time span. The forces of scar contracture in the severe trauma bed are extremely tenacious; what looked like adequate soft tissue contour at 3-6 months can become distorted at 1 year. If this is the case, it is useful to have some bulk remaining for additional surgical manipulation.

The variability in volume loss within the different vascularized soft tissues available for transfer to the head and neck is considerable. If the soft tissue component of a flap is to be used for internal volume replacement, it is crucial that vascularized adipose tissue be included either as a component of a de-epithelialized fasciocutaneous skin paddle or as subcutaneous adipose tissue transferred with a myofascial flap carrier. If the adipose tissue is transferred with muscle, the bulk of the muscle reliably decreases markedly over 6-8 months. When the flap is being placed under native skin, the muscle should be inset lateral to the adipose tissue and skin grafted, and a tight closure to accommodate the muscle and adipose tissue should be avoided. The area that is skin grafted can be excised in several months, and the scar revised. If the vascularized adipose tissue is trimmed to obtain wound closure without skin grafting, when the muscle atrophies, the volume replacement is likely deficient. The vascularized adipose tissue often not only retains its volume following transfer, but also increases in volume if the patient undergoes weight gain. In general, if bulk is required for contouring or filling a soft tissue defect, the most reliable and predictable tissue to use is vascularized adipose. The final volume adjustments should always be conservative and performed no sooner than 8-12 months following surgery.

Unlike many cancer patients, most facial trauma patients have remaining dentition following the major reconstructive procedure. With the use of these dental abutments for retention and stabilization, a trial with a tissue-borne denture is justified before subjecting the patient to the time and expense of an implant retained or implant-borne denture rehabilitation. Interim denture prosthesis can be easily fabricated for trial purposes. If it seems to function satisfactorily, a permanent tissue-borne denture is made. If not, then dental rehabilitation with implants can be started.

The major problem encountered with implant placement in the patient population with severe perioral trauma is the dynamic nature of the perioral healing and contracture, resulting in implant placement that is too close to the final position of the lips. This problem is complicated by the necessary delay in final oral stoma reconstruction (so that adequate exposure to work in the oral cavity is maintained until after most of the dental rehabilitation is done). In addition, the scarred, reconstructed oral stoma is considerably more rigid than the normal lip aperture, and nearly all patients who have had significant loss of lip and perioral soft tissue have some degree of microstomia after the final oral stoma reconstruction to prevent drooling. If this problem is anticipated, the surgeon should place the implants on a slightly more lingual position than is normally used. Generous vestibuloplasties also help to bring the lips forward away from the implant-bearing surface of the bone.

Refinement of the nasal reconstruction is performed at this time. Attaining a normal nasal structure in these patients can be extremely challenging. The surrounding contracture forces distort all, but the most stable underlying bone or cartilage framework. Dorsal bone grafts should be rigidly fixed to the glabellar area with miniplates of at least 1.5 mm. When cartilage grafts are used in reconstruction of the nasal ala, they should be obtained from the costal margin. Auricular and septal cartilages are too weak to withstand the surrounding scar contracture in these severe injuries and may not maintain a satisfactory contour. If color match is poor in a transplanted skin paddle, the use of medical tattooing may be used to soften the color differences with the surrounding tissues. This should be done in a very conservative and staged fashion, initially starting in an area that is least visible. If a facial prosthesis (for the nose or other structures) or an ocular prosthesis is to be used, these should be fabricated at this time.

For an ocular prosthesis to be retained and have a natural appearance, an adequate conjunctival pocket is required. When a substantial amount of the conjunctiva has been destroyed in the trauma, mucosal grafting is used to restore this depth. If possible, the patient should be referred to a professional cosmetologist or counseled regarding hairstyle, makeup, and adjunctive measures, such as shaded glasses, that enhance the positive aspects and camouflage the negative aspects of the final reconstruction results.

The key aspects have been summarized in Table 3.

Table 3

The Final stage of management

The present case under our care stresses the importance of educating the masses, especially school-going children, about the dangers of unsafe handling of even these low voltage devices like pencil batteries, car batteries, inverter cells, etc.

The plastic surgeon, when dealing with such patients with severe facial trauma with soft tissue and bony defect secondary to blast injury, must carefully consider the available methods of soft tissue reconstruction and bony fixation.[7] The choice of procedure in these cases depends mainly on the likelihood of success, donor site morbidity, and potential for complication.

Length limitations of the vascular pedicle, unreliability of bone transfer, and poor contourability of these relatively bulky flaps into complex and often composite defects, however, remain problematic. Local or regional flaps have also been used for the reconstruction of these defects, but the bulkiness of these flaps and increased numbers of surgeries required are the shortcomings of these types of flaps. Free tissue transfer has made it possible to bring well-vascularized bone and soft tissue into a hostile wound environment with excellent survival of the flap tissues or free-bone grafts invested by the vascularized flap. This has allowed for simultaneous reconstruction of the bony facial skeleton and the overlying soft tissue soon after injury. With this reconstructive technique, there has been a shift away from delayed bony and soft tissue reconstruction toward definitive reconstruction as soon as possible following injury to minimize the scar contracture of the facial soft tissues.

CONCLUSION

Although there are indications for all of these techniques, free tissue transfer has dramatically expanded the armamentarium of the reconstructive surgeon. However, the presence of microvascular expertise is required for these techniques, which is a shortcoming in most centers in the rural areas. So, a staged approach to the reconstruction of the severe facial trauma patient is recommended. Having a checklist of goals allows a systematic and structured approach and prevents oversight. The management of these patients can be broken into three steps defined by specific reconstructive, rehabilitative, and global patient management goals. The steps are not defined by time and may overlap with each other or may require more time at a particular phase so that all of the goals are met.

We chose the deltopectoral flap due to its ruggedness and ability to be used for both lining and external cover. Also, in children, the skin of this region is thin, and hence a good replacement for tissues of the facial region. As can be seen in this case, good results can be achieved by using simple and time-tested techniques.