Initial Evaluation
Primary Survey
The initial presentation of soft tissue injuries can vary significantly in terms of
severity, complexity, and concomitant injuries. The initial assessment should follow
well-established, systematic trauma protocols such as the Advanced Trauma Life Support
(ATLS) program developed by the American College of Surgeons (ACS) Committee on Trauma
(CoT) for the accurate and rapid assessment of a patient's condition and injuries,
resuscitation, and transfer to higher levels of care if necessary.[3]
[4] The primary survey focuses on airway evaluation with cervical spine control, breathing
with adequate oxygenation and ventilation, circulation to ensure adequate tissue perfusion,
disability, and exposure of all injuries.[4]
[5]
[6] At our center, this is a multidisciplinary approach involving emergency medicine,
trauma surgery, anesthesia, and the craniofacial service. Facial soft tissue injuries
can be associated with threats to the airway requiring airway stabilizing maneuvers
or devices, intubation, or surgical airway.[5] Injuries of the head and neck region can be associated with life-threatening blood
loss and ensuring appropriate hemostasis and resuscitation is necessary.[6]
Secondary Survey
Once the patient is stabilized, the secondary survey ensues with a thorough head-to-toe
physical examination to identify all anatomic injuries. This exam is informed by a
thorough history including detailed information about the mechanism of the injury,
symptoms, allergies, medications, past medical and surgical history, and last per
os (PO) intake.[7] Based on the secondary survey, imaging studies including plain film radiographs
and/or cross-sectional imaging are obtained to better elucidate specific injuries.
Other considerations include a tetanus vaccine booster and antibiotic prophylaxis
for bite injuries or gross contamination.
Craniofacial Exam and Imaging
A complete head and neck exam should be performed by the craniofacial surgery team.
This includes an assessment of all soft tissue injuries, cranial nerve exam, and an
evaluation for bony trauma. A more thorough discussion is included below by anatomic
region. Standard imaging at our center includes a maxillofacial computed tomography
(CT) scan with 3-dimensional reconstructions to identify bony injuries.[8]
[9] Plain films in craniofacial injuries are not preferred due to their limited diagnostic
accuracy and utility for surgical planning. While a dental panoramic radiograph is
useful for evaluating the upper and lower jaw, this is not the optimal imaging modality
in the trauma setting.[9] CT angiography of the head and neck are obtained for patients at high risk for or
with symptoms of blunt cerebrovascular injury (BCVI) ([Table 1]).[10]
[11]
[12]
Table 1
Considerations for CT angiography of the head and neck to evaluate for blunt cerebrovascular
injury
|
High risk factors for BCVI
|
|
Lefort II or III Fracture
Mandible fracture with high energy mechanism
All skull base fractures
Any fracture of C1, C2, or C3
Traumatic cervical spine subluxation
Cervical spine fracture extending to transverse foramen
Cervical spine fracture with thoracic or lumbar spine fractures
Great vessel injury in the thorax
|
|
Signs or Symptoms of BCVI
|
|
Arterial hemorrhage from the neck, mouth, nose, or ears
Gunshot wounds to the head, face, or neck
Near hanging resulting in cerebral anoxia
Large or expanding cervical hematoma
Carotid Bruit in a patient < 50 years old
Cerebral infarction on CT or MRI
Unexplained central or lateralizing neurologic deficit, TIA, or Horner's syndrome
Diffuse axonal injury with GCS <6
|
Principles of Early Management
Irrigation and Debridement
Initial management focuses on wound cleaning with irrigation, hemostasis, and debridement
of nonviable tissue. Patient comfort may be improved with local or regional anesthesia
prior to management. Irrigation with normal saline is recommended, with the use of
syringe or pulse lavage for increased pressure when needed.[13] In cases of gross contamination, the use of a dilute soap solution for irrigation
can be considered. Antiseptic solutions such as chlorhexidine and povidone are not
routinely used due to the risk of cellular injury to the traumatized tissue and mucosal
surfaces.[13] At our center, in small wounds without gross contamination, we recommend large volume
irrigation (∼500 cc to 1 L of normal saline) to appropriately cleanse the wound. In
larger or grossly contaminated wounds, large volume irrigations should continue until
the wound appears clean without any evidence of contamination. Manual extraction of
embedded foreign material may be necessary to fully decontaminate the wound. Hemostasis
is initially controlled with direct pressure and/or the addition of epinephrine to
local anesthetic. Electrocautery of injured vessels should be reserved for uncontrollable
bleeding, to spare additional damage to surrounding soft tissue. Arterial bleeding
may accompany cranial nerve transection (such as the facial or trigeminal nerves)
and targeted hemostasis helps prevent further damage to traumatized nerve endings.
Debridement of obviously nonviable tissue should be completed conservatively to preserve
adequate tissue for repair. When in doubt, the practitioner should err on the side
of tissue preservation. Given the significant vascularity of the face, repaired tissue
may survive or engraft following repair.[13]
Soft Tissue Abrasions and Traumatic Tattoos
Soft tissue abrasions that spare full thickness injury to the dermis do not require
surgical closure but should follow the principles of wound irrigation and debridement.
Soft tissue lacerations disrupting the dermis should ideally undergo primary closure
within 8 hours of the injury.[2] Partial thickness abrasions may be treated conservatively with local wound care.[2] We typically recommend topical petroleum ointment or 3% bismuth tribromophenate
in a petroleum based fine mesh gauze (Xeroform) for initial wound care as it is effective
and simple for patients to learn in the acute setting. Patients should be counseled
that bacitracin ointment can cause a contact dermatitis in 15% of patients and if
used, should be limited to 3–4 days duration.[14] Blast, ballistic, firework, and road rash injuries can all result in particulate
inclusions producing a traumatic tattoo ([Fig. 1]).[15] Early management starts with scrubbing the wound using sponges, surgical scrub brushes,
or wire brushes within 6–72 hours, followed by forceps removal of particles by surgical
loupe vision. Secondary management of long-lasting traumatic tattooing includes dermabrasion
direct excision, or laser treatment. Laser treatment is not recommended for gunpowder
injuries due to the risk of igniting the inclusions and producing significant tissue
damage.[16]
Fig. 1 Traumatic tattooing of the right cheek from embedding of particulate matter (in this
case asphalt) into an open soft tissue injury.
Soft Tissue Avulsions
Avulsion injuries are characterized by the separation and subsequent loss of tissue.[2] Varying degrees of soft tissue loss may be involved with marginal, partial, or complete
necrosis. In the acute setting, the avulsed tissue should be assessed for viability.
This involves evaluating the dimensions of the intact skin bridge as well as visual
inspection of the tissue including capillary refill of the avulsion flap and bleeding
from the wound edges. Tissue that is obviously non-viable should be debrided conservatively.
Otherwise, primary repair should be attempted. Elasticity and edema of avulsed tissue
may cause soft tissue retraction, placing undue tension on the flap with anatomic
repair. In these cases, the tissue should be laid down on the wound with minimal tension
and gently sutured in that position to prevent necrosis of the entire avulsion flap.
The remaining open areas of the wound should be allowed to heal secondarily with local
wound care. Amputation of specialized tissue such as the auricle, nose, and lip may
be amenable to microvascular replantation if an identifiable artery is available for
anastomosis. If venous anastomosis is not available, hirudotherapy, also known as
medicinal leach therapy, may be used to ease venous congestion until neovascularization
occurs. Significant soft tissue loss not amenable to microvascular replantation may
require delayed local rotational flaps, grafts, or free tissue transfer.[17]
High Energy Injuries
High energy injuries such as ballistic or firework injuries often require complex
multidisciplinary care. In the acute phase, establishing a secure airway and enteral
access is important in initial resuscitation. Placement of tracheostomy and gastrostomy
tube may also facilitate future reconstructive needs.[4]
[5] Urgent irrigation and debridement, preliminary skeletal fixation, and soft tissue
repair is recommended as it has been shown to reduce the number of surgical procedures,
shorten hospitalizations, and reduce rates of soft-tissue contracture.[18] Once the patient is physiologically stable, definitive reconstruction can be performed
in a staged fashion. It is important to consider the psychosocial impacts of the injury
and recovery process for the patient and provide adequate counseling and support.
Evaluation and Management by Anatomic Region
Scalp
Evaluation and Special Considerations
A careful examination of the scalp must be performed in patients with facial trauma
as lacerations can be hidden by the hair. Injuries to the scalp are associated with
heavy bleeding due to the rich vascular supply of the region. Hemostasis is critical
for limiting blood loss and improving visualization for repair. Electrocautery should
be used precisely to limit injury to hair follicles and prevent alopecia[2]; direct pressure is effective but careful ligation of injured vessels may be required.
Routinely shaving the scalp prior to repair is not necessary and can be associated
with an increased risk of infection.[19] However, in some cases removing surrounding matted hair may be necessary for sufficient
wound cleansing and visualization. Care should be taken to prevent stray hair from
entering the wound.[12] Using a local anesthetic containing epinephrine can help with hemostasis to facilitate
repair. The addition of 8.4% bicarbonate solution to 1–2% lidocaine in a 1:10 ratio
improves discomfort associated with injection of local anesthetic by neutralizing
the acidity of lidocaine.
Management
The goals of managing scalp injuries are to achieve a tension-free closure, restore
the structure of the scalp, and protect the cranium.[2] Lacerations can usually be repaired with primary closure[20]; a layered repair is recommended including periosteum, galea, and dermis. Undermining
tissue or scoring the galea can be considered to facilitate the closure in areas of
high tension. Surgical staples are preferred for superficial layer of closure in scalp
lacerations. Injuries with large areas of dead space may require placement of a drain
and a pressure wrap to reduce the risk of hematoma, seroma, and secondary complications.
In cases of complete scalp avulsion, replantation should be considered if the scalp
has been preserved appropriately and microsurgical capabilities are available.[21]
Forehead
Evaluation and Special Considerations
Initial examination of the forehead includes an evaluation of the facial musculature.
The frontal branch of the facial nerve innervates the frontalis, orbicularis oculi,
and corrugator supercilli muscles. This nerve can be found along Pitanguy's Line,
which is defined as a line connecting 0.5 cm below the tragus to 1.5 cm above the
lateral eyebrow.[22] For any injuries in this area, the function of this nerve must be assessed and documented
prior to injecting local anesthetic or attempting repair.[22] The sensory innervation of the forehead is derived from the supraorbital and supratrochlear
nerves, which can be blocked directly via injection of local anesthetic along the
medial third of the supraorbital rim.[23] The addition of epinephrine and bicarbonate to local anesthetics can help with hemostasis
and enhance comfort, respectively.[24]
Management
Management should focus on reapproximating the soft tissue with careful consideration
to the brow margins, existing forehead rhytids, and hairline of the forehead. Primary
repair is often possible, particularly without substantial tissue loss. Undermining
the surrounding tissue can relieve tension. Smaller defects may benefit from elevation
of a subcutaneous flap while larger defects may benefit from elevation of a subgaleal
flap.[25] The level of tissue elevation may also be determined by the depth of the injury
or avulsion of existing tissue. Relaxing incisions in the galeal (also known as galeotomies)
perpendicular to the vector of maximal tension allows for additional tissue advancement.
While staples are appropriate on the scalp, they should be avoided on facial skin
due to the associated risk of scar formation at the penetration site.[25] If the eyebrows are involved, they should not be shaved but rather used as important
landmarks for repair.[19] If additional skin incisions are necessary to facilitate closure, designing the
incision in the horizontally oriented relaxed skin tension lines is preferred.[25] Healing by secondary intention can result in adequate cosmesis and secondary scar
revision could result in a lower overall scar burden than the use of local flaps or
skin grafts in the acute setting.
Periorbita and Eyelids
Evaluation and Special Considerations
Trauma to the periorbital region should raise concern for associated orbital or globe
injury. It is important to perform a thorough examination including visual acuity,
extra-ocular movements, intraocular pressure (IOP) measurements, and fluorescein eye
stain test.[26] Additionally, physical examination should include an assessment for the presence
of bony step-offs, enophthalmos, or vertical dystopia, which are suggestive of orbital
bone injury.[26] Telecanthus suggests an underlying bony injury or avulsion of the medial canthal
tendon.[27] Any evidence of fat herniation into the laceration should raise concern for violation
of the orbital septum, which necessitates operative exploration. Lacerations near
the middle third of the eye should raise concern for a lacrimal apparatus injury,
especially when associated with epiphora, which will require interrogation of the
canaliculi.[28] Early ophthalmology consultation is recommended for globe or lacrimal apparatus
injury.
Severe orbital pain, difficulty opening the eyes, proptosis, or loss of vision with
elevated IOPs are suggesting of retrobulbar hematoma or orbital compartment syndrome.[4]
[7] This is a vision-threatening emergency and requires immediate lateral canthotomy
and cantholysis for decompression; patients should also be counseled that this could
develop in a delayed fashion and be given strict return precautions.
The innervation of the eyelids is complex and includes territories of the supratrochlear,
supraorbital, lacrimal, zygomaticofacial, infraorbital, and infratrochlear nerves.[23] While specific nerve blocks could allow for anesthesia without affecting the motor
function of the orbicularis oculi muscle, local infiltration is typically necessary
for complete anesthesia.
Management
As discussed above, the management of periorbital injuries may require multidisciplinary
care between craniofacial surgery and ophthalmology; in some hospital systems, oculoplastic
subspecialists may primarily manage these injuries. Once again, primary repair is
preferred when possible. Eyelid anatomy is divided into anterior lamella (skin and
orbicularis oculi) and posterior lamella (tarsus and conjunctiva). The surgeon should
identify the level of injury and repair the lamella individually.[27] Care must be taken not to injure the globe, obstruct the lacrimal apparatus, or
cause a retrobulbar hematoma. Sutures should be placed at the gray line and lash line
in an everted fashion to restore the contour of the eyelid margin followed by repair
of the tarsal plate with resorbable sutures. When repairing the anterior lamella,
care should be taken to only incorporate skin into the suture. Reapproximating the
orbicularis oculi muscle is not necessary and the incorporation of deeper tissues
in the repair can cause scarring of the eyelid skin to the orbital septum, cause tethering
of the eyelid ([Fig. 2]). Small injuries to the conjunctiva can heal secondarily while larger injuries require
repair with a fine resorbable suture to prevent entropion. Injuries with less than
25% full thickness loss can be closed primarily[27] while larger defects require more complex reconstructions such as lid-switch flaps,
Tenzel semicircular advancement flaps, and grafting.[29] Any shortening or deficiency in the lamella as well as scarring can result in entropion
or ectropion; scar massage and observation can often result in resolution of ectropion
over time while shortening of the lamella and severe scarring will require secondary
grafting.
Fig. 2 Upper lid Lagophthalmos following left upper eyelid laceration repair with deepening
of left upper eyelid fold with the eye open (left) and medial lagophthalmos with eye
closure (right) due to tethering of the upper eyelid to the orbital septum.
Cannalicular injuries require interrogation by an ophthalmologist or other provider
experienced in treating these injuries. The canaliculi appear as thin white tubular
structures in the medial third of the eyelids and are better visualized under loupe
magnification. Once injuries are identified, they are usually repaired over a silastic
lacrimal stent, which is left in place for 2–3 months.[28]
Ears
Evaluation and Special Considerations
The ears are unique that the anterior skin is tightly adherent to the underlying auricular
fibrocartilage that gives shape to the external ear while the posterior skin is thicker
and more mobile with a less complex topography.[30] They are prone to injury because they are thin, exposed on two sides, and prominent.
Visual examination of the ears is usually sufficient for diagnosis and treatment.
Any skin loss or damage to the underlying cartilage should be identified. The external
auditory canal (EAC) also should be examined with an otoscope to evaluate for foreign
bodies, hemotympanum, tympanic membrane perforation, and lacerations. Skull base fractures
can be associated with mastoid ecchymoses (Battle sign),[31] CSF otorrhea, or otorrhagia. Lacerations of the anterior EAC may be associated with
mandible fractures due to close proximity with the temporomandibular joint. It is
important to ensure that the patient does not have an auricular hematoma, a subperichondrial
collection of blood due to shear forces that separate the attachments of the soft
tissue to the perichondrium.[30]
[32] This can take hours to develop following blunt trauma and presents as a painful
swelling that obliterates the normal topography of the ear. If untreated, the blood
will clot and organize into a fibrotic mass that can calcify and result in a deformity
known as a “cauliflower ear”[32].
The sensory innervation of the ear is also complex. The upper two-thirds of the anterior
surface is innervated by the auriculotemporal nerve and the posterior surface is innervated
by the lesser occipital nerve. The great auricular nerve provides sensation to the
lower third of the ear.[23] These nerves can be blocked by injecting local anesthetic in a diamond pattern around
the ear.[33] However, the concha and EAC are innervated by the auricular branch of the vagus
nerve, Arnold's nerve, which requires direct infiltration for anesthesia.
Management
The majority of ear lacerations can be repaired primarily. The blood supply to the
ear is robust and the cartilage will survive if one surface remains in contact with
well vascularized tissue. Sutures should be placed to approximate the skin at known
anatomic landmarks to prevent distortion of the ear then the rest of the skin repaired.
The cartilage does not need to be routinely repaired if the soft tissue envelope repair
restores the normal contours.[34] Soft tissue injuries around the EAC can result in stenosis or occlusion of the canal
so stenting with an ear wick and instillation of antibiotic ear drops such as ciprofloxacin
may be necessary.[35] The data are unclear on the use of antibiotics to prevent chondritis and routine
use is not indicated. Some authors recommend antibiotic use in the setting of grossly
contaminated, degloved or exposed cartilage. Efforts should be made with local advancement
of the soft tissues to provide coverage for the entirety of the cartilage but if some
remain exposed, local wound care can be performed with mafenide acetate, which has
good penetration into the cartilage
Amputations of the ear provide unique challenges with vascularity. Incomplete amputations
should be primarily repaired, and success has been reported even in millimeter thin
pedicle remnants. Those with marginal pedicles may have inadequate venous outflow
so the ear should be monitored following repair for the early initiation of hirudotherapy/medicinal
leech therapy if there is evidence of venous congestion. For complete amputations,
microsurgical replantation can be considered whenever feasible as this will result
in the best cosmesis if there is an adequate vascular pedicle.[36] Case Reports have shown survival after replantation based on a single artery with
the use of leeches for venous outflow.[37] For complete amputations of partial ears, there are many reported strategies including
subcutaneous banking of the cartilage or coverage with local and regional flaps. However,
the denuded cartilage does not retain its shape and often becomes fibrotic and shapeless,
resulting in a suboptimal outcome. Therefore, our center usually recommends local
advancement of the skin for primary closure and staged secondary reconstruction ([Fig. 3]).[36] Preserving the postauricular skin and blood supply to temporoparietal fascia during
primary repair aids in secondary reconstructive options.
Fig. 3 A significant soft tissue and cartilage amputation from bilateral ears following
a dog attack (left, center). The amputated parts were available (right) but given
the mechanism and extent of the injury with no identifiable blood vessels for replantation,
the decision was made to stabilize the soft tissues and plan for a staged reconstruction.
The management of auricular hematomas requires drainage of the hematoma, hemostasis,
and application of a bolster to prevent reaccumulation of the blood.[32] Simple aspiration is insufficient since it will remove the hematoma but not prevent
the reaccumulation into the subperichondrial space. Drainage can be accomplished through
an incision over the hematoma, typically parallel to the antihelix or helix. The skin
and perichondrial flap are elevated and suction is used to remove the hematoma. After
irrigation, hemostasis must be achieved. At our center, we form a bolster using Xeroform
and/or dental rolls, mold it to the contours of the ear, and secure it in place with
through-and-through sutures. A headwrap is applied and the bolsters are removed in
5–7 days.[29]
Nose
Evaluation and Special Considerations
The prominence of the nose on the central face predisposes it to injury. Nasal bone
fractures are the most common facial fractures and usually occur without any soft
tissue injuries. The nose consists of three components including the external covering,
support structures, and nasal lining. Examination of the nose involves an assessment
of the soft tissues and bony/cartilaginous framework as well as the external and internal
anatomy. Any external lacerations and tissue loss as well as asymmetries and deviations
of the nasal dorsum should be identified and associated with any palpable fractures
or crepitus of the nasal bones and cartilages. An internal nasal exam should be performed
with a nasal speculum, adequate light, and suction to evaluate for bleeding, mucosal
lacerations, exposed cartilage or bone, septal injuries, and septal hematoma.[38] Airflow through the nose should be assessed and the patient should be asked about
previous nasal injuries and surgeries as well as breathing problems.
Nasal hemorrhage can cause significant blood loss, distress, and airway compromise.[4]
[6]
[39] Initial management includes head of bed elevation, external pressure, application
of nasal decongestant, and placement of nasal packing to apply direct pressure on
the nasal mucosa for hemostasis.[39] A variety of strategies exist for nasal packing and to achieve hemostasis, including
the use of vasoconstrictive agents including oxymetazoline, phenylephrine, or cocaine
and hemostatic agents such as topical tranexamic acid, oxidized cellulose polymer
(Surgicel), and fibrin sealant (Tisseal).[40] Direct nasoendoscopy may be required for targeted cautery, particularly in the posterior
nasal cavity. If there is continued hemorrhage with placement of anterior nasal packing,
posterior nasal packing can be performed with the passage of a Foley catheter through
the nares, inflation of the balloons, and pulling back of the cathethers to apply
pressure to the posterior mucosa.[4] Placement of a posterior pack requires continuous hemodynamic monitoring in an intensive
care unit. If hemorrhage is uncontrollable, either IR embolization or surgical exploration
may be necessary.[39]
Nasal septal hematomas appear as a central swelling of the septal mucosa often causing
complete occlusion of bilateral nasal cavities. These occur from blood accumulation
between the perichondrium and the septal cartilage. This results in cartilage necrosis
and must be identified and managed acutely to prevent the development of septal perforation,
septal abscess, and saddle nose deformity.[38]
Given the complex innervation of the nose, multiple injections of local anesthetic
are required for a combination of nerve blocks and local infiltration. The infraorbital
nerve blocks can provide anesthesia to the lateral nasal side walls.[41] A nasal block can be performed with the injection of anesthetic along the superior,
lateral, and inferior aspect of the nose to numb the nasal dorsum, side wall, and
tip.[23] However, contributions from the anterior ethmoid nerve is difficult to inject intranasally
with local anesthetic. Mucosal anesthesia can be achieved with nasal packing using
cottonoids soaked in an anesthetic solution.[41] Major nasal injuries may benefit from general anesthesia.
Management
The goal of nasal repair is to restore normal appearance without secondary nasal obstruction.
Lacerations should be repaired in layers from the inside out. The nasal lining is
repaired first with resorbable sutures with the goal of prevent intranasal cartilage
exposure. Lacerations of the upper and lower lateral cartilages should be repaired
to restore the structural framework of the nose. When repairing the skin, sutures
should be placed to align the nasal landmarks to ensure an appropriate shape and contour
of the nose. In particular, eversion of skin along the nostril margin may help prevent
future notching from scar contracture. In general, loss of nasal soft tissue should
be treated with local flaps and grafting within weeks of the injury as there is significant
potential for contracture and collapse with secondary healing.[42] Severe injuries often require delayed nasal reconstruction or rhinoplasty,[42] which can make future reconstruction and rhinoplasty challenging.
If a nasal septal hematoma is identified, it should be evacuated to prevent long term
complications and deformities.[38] A small incision is made at the caudal aspect of the hematoma, which is then drained
using suction and irrigated with saline. Once this is complete, hemostasis is ensured
and the perichondrium is replaced over the septum. Multiple through-and-through resorbable
sutures are placed through the septum to bolster the perichondrium and prevent reaccumulation
of blood. Doyle splints or nasal packing may be applied for additional pressure to
prevent reaccumulation of blood.
Cheek
Evaluation and Special Considerations
Evaluation of cheek lacerations requires a thorough assessment of facial nerve and
parotid duct injury as these must be identified and addressed immediately.
The facial nerve exits the skull base through the stylomastoid foramen and divides
into its five main branches within the parotid gland.[43] The zygomatic and buccal branches are at the highest risk for injury with cheek
lacerations due to their location.[44] The zygomatic branch runs inferior to the zygomatic arch while the buccal branch
travels over the masseter muscle parallel to the parotid duct. Multiple branches and
communicating branches exist, particularly medial to a vertical line from the lateral
canthus. Injury to zygomaticobuccal branches medial to the lateral canthus in the
midface do not typically require nerve exploration due to expected redundancy and
compensation. A thorough examination of facial nerve function should be performed
prior to injection of local anesthetic to assess for signs of facial paralysis.
The parotid duct, also known as Stenson's duct, follows a line from the tragus to
the midpoint of the philtrum. The duct exits the superficial part of the parotid gland
anteriorly and passes over the masseter muscle prior to entering the oral cavity through
the buccinator muscle. The duct can be identified intra-orally via a papilla across
from the maxillary second molar.[45] An injury in the medial third of this line raises concern for an injury of Stensen's
duct; injuries laterally can be associated with a direct injury to the parotid gland.
Given the association of the buccal branch of the facial nerve to the parotid duct,
injuries to the facial nerve should raise concern for a parotid duct injury. Massage
of the parotid gland from lateral to medial allows for assessment of salivary fluid
exiting the duct or the wound. The majority of saliva produced by the parotid occurs
during eating and delayed salivary leak may occur once the patient resumes a diet.
Management
Cheek lacerations without significant soft tissue loss should be repaired primarily
with a layered closure to approximate the mucosa, muscle, and skin. Relative laxity
of the skin in the cheek also facilitates primary closure. The vector of tension should
run parallel to the margin of the eyelid to avoid causing retraction or ectropion
of the lower eyelid. The critical aspects of cheek lacerations are the identification
and appropriate management of facial nerve and parotid gland/duct injuries.
Facial nerve transections should be repaired primarily. Early surgical exploration
should be performed within 72 hours from the time of injury as this will allow for
the use of a nerve stimulator to help identify the distal nerve endings ([Fig. 4]).[44]
[46] Beyond 72 hours, Wallerian degeneration, or distal nerve demyelination, prevents
stimulation of distal nerve endings. If the proximal nerve ends cannot be identified,
the facial nerve trunk can be identified either in the parotid gland or in the mastoid
bone and followed distally. The nerves should be repaired primarily using standard
microsurgical techniques, taking care to avoid tension at the coaptation. If necessary,
nerve grafts can be used to bridge gaps and prevent tension. If surgical exploration
is not possible within 72 hours, delayed exploration may be considered after reduction
of tissue edema and inflammation. Secondary reconstructive procedures such as cross-face
nerve graft, cranial nerve transfers, temporalis tendon transfer, and free functional
muscle transfers can be performed in a delayed fashion.[46]
Fig. 4 Initial midface soft tissue injury requiring operative exploration and zygomaticobuccal
nerve repair (left), immediate post-operative facial function with right midface weakness
(middle), and 8 month post-operative photograph (right) with improvement of facial
function.
Parotid duct injuries can be identified by cannulation of the duct papilla. A 22-gauge
catheter is inserted into Stensen's duct intra-orally and a small quantity of saline,
methylene blue, or Propofol can be injected.[45]
[47] If the fluid is seen in the base of the wound, a parotid duct injury can be confirmed.
Duct injuries can undergo primary microsurgical repair over a silastic catheter or
angiocath. The stent is secured distally and left in place for 10–14 days while the
duct heals.[47] Distal injuries can be diverted into the oral cavity more proximally by passing
the distal end of the duct through the buccinator muscle and securing it to the oral
mucosa.[47] Injuries that are too proximal for primary repair or diversion can be managed with
ligation of the parotid duct.[47] This obstruction will eventually atrophy; pressure dressing, antisialogogues such
as anticholinergic medications, and/or botulinum toxin can be used to help reduce
salivary gland function during this time. Direct parotid gland injuries can be managed
with the placement of a drain for 5–7 days in addition to reducing salivary function.
Sialocele formation can be managed with serial aspirations, pressure dressings, and
antisialogogues.
Lips
Evaluation and Special Considerations
The oral cavity must be carefully examined. The occlusion should be assessed and any
loose or missing teeth should be identified; missing teeth must be accounted for or
imaging obtained to ensure they have not been aspirated. Evaluating depth and anatomical
involvement of lip lacerations is important for restoring form and function of the
lips; care must be taken not to miss intra-oral lacerations and injuries. The anatomy
of the lips consists of three layers of tissue: mucosa, muscle, and skin. Landmarks
include philtrum, cupid's bow, oral commissures, and the vermillion cutaneous border
which is the most important landmark.[2] Retraction of the orbicularis oris muscle often splays open lip injuries making
them appear larger than they are.
Marking anatomical landmarks, such as the vermillion, is important prior to injecting
local anesthesia that may obscure such landmark.[2]
[48] The upper lip receives sensory innervation from the infraorbital nerve, found at
the buccal mucosa above the canine tooth. The lower lip receives sensory innervation
from the mental nerve, located at the apex of the second premolar. The use of infraorbital
blocks and mental blocks will help prevent distortion of the tissue and facilitate
anatomic repair.[23] However, local infiltration of anesthetic may be required in the lateral lip and
commissures.
Management
Goals of repair include maintaining oral competence, optimizing aesthetic outcome,
and preventing microstomia.[48] Repair of full thickness lip lacerations requires the careful approximation of all
anatomic structures. Often, a small length of the orbicularis muscle needs to be dissected
to facilitate muscle repair; failure to repair the orbicularis can result in a whistle
deformity, similar to what is seen in inadequate cleft lip repairs. Once the muscle
is approximated, tension is offloaded from the rest of the tissues. This allows for
anatomic approximation of the philtrum, cupid's bow, vermillion, and white roll.[19] Vermillion discrepancies as little as 1 mm may be visible from speaking distance
so care must be taken to be as accurate as possible. Once the critical landmarks are
approximated, the skin and the mucosa can be repaired.
Some partial thickness lip injuries can be treated with local wound care and possible
secondary scar revision while in other cases, it is favorable to convert a partial
thickness injury to a full thickness defect with excision of the remaining tissue.
Full thickness defects encompassing less than 30% of the lip can be closed primarily.[20] The patient should be warned that their lips might feel tight but will relax over
time. Soft tissue loss greater than 30% of the lip may require local flap reconstruction.
