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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_537_Библиотеки_им_академика_М_И_Перельмана
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Fig. 5 Internal fixation of various craniofacial bones from panfacial fractures using titanium plates
and screws [57]
When necessary, external fixation of the reduced fracture sites can be
performed temporarily for complex injuries prior to final internal fixation.
This technique involves placement of pins through the skin, which are
fastened to internal bone and external scaffolding [56].
3.2.2 Bone Grafting
Bone grafts are utilized in the reconstruction of severe craniofacial bone
defects and can replace lost osseous tissue while providing stability to the
craniofacial skeleton. Autologous bone grafts are harvested directly from
the patient and have been considered as the gold standard for reconstruction
of bony defects [58]. Additional tissue options are listed below [59]:
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Osseous xenografts: composed of organic bone from a different species
(porcine, bovine)
Allogenic grafts: harvested from human cadaver donors
Alloplastic grafts: composed of synthetic materials (bioactive glass,
polymers, tricalcium phosphate)
Bone grafts should be stabilized in place once they are positioned, using
fixation screws or pins. It is recommended to use at least two screws for
each piece of grafted bone. Titanium mesh may be utilized when particulate
grafts are placed (e.g., bone chips), and polytetrafluoroethylene (PTFE) is
placed to protect the graft when primary closure is not
possible/contraindicated [59].
There are various factors to consider when a bone graft is needed,
including size of the defect, reconstructive goal, and tissue availability.
When more than 6–8 cm of bone is lost due to trauma or craniofacial
anomalies, bone flaps should be harvested with their own existing
vasculature to ensure adequate perfusion and long-term survival. In these
cases, it may be beneficial to harvest composite flaps containing bone,
cartilage, and overlying soft tissues. Common donor sites for bone flaps
include the free fibula, iliac crest, and scapular tip [60].
Cancellous or cortical autogenous bone may be harvested, depending on
the reconstructive need and tissue availability. Cancellous grafts contain
large spaces between the trabeculae, allowing for more rapid perfusion with
avascular grafts. Repair of bony gaps is generally repaired with inlay grafts
and indicates the use of cancellous bone [61, 62].
Cortical bone grafts tend to maintain their mechanical strength after
transplantation, although bone revascularization occurs more slowly and
often incompletely [63]. These are typically used to repair volume
deficiency, as with malar augmentation [60].
4 Initial Assessment
Reconstructive surgery is planned around the patient’s condition and their
ability to tolerate anesthesia and recovery. Often, patients presenting with
severe injuries or cancer are cleared by the trauma team and oncologic
specialists, respectively, prior to reconstruction. There are various
indications for initial examination unique to head/neck trauma, burns, and
neoplasms, which are discussed in greater detail throughout the section.
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4.1 Craniofacial Trauma
Patients presenting with life-threatening traumatic injuries should be
assessed for reconstructive surgery after severe blood loss is controlled and
the airway is stabilized. Airway compromise can occur secondary to
hemorrhage, edema, or foreign body entrapment, or may be caused by
direct trauma. Hemorrhage as a direct result of maxillofacial injury is
commonly attributed to sinus vessels transected with upper midfacial or
nasoethmoidal fracture, although other causes should be ruled out at the
initial consultation. After blood loss is controlled with packing or
tamponade (balloon catheter, ligation), additional assessment with
angiography is used to locate the offending vessels when another source of
bleeding is suspected [64].
Cervical spinal injury occurs in to 3–7% of facial trauma cases, and the
general reconstructive timeline will depend on the indicated management of
spinal cord injury or vertebral fractures [65–67]. In a previous study, nearly
80% of patients presenting with facial fractures were found to have related
traumatic brain injury (TBI) [68]. When the extent of injury is unknown,
precautions relevant to TBI and cervical spine injury should be followed
until the patient is stabilized and confirmatory imaging is obtained [69].
Emergent craniofacial fractures do not always occur with superficial
tissue damage, while seemingly innocent isolated lacerations can induce
nerve damage with devastating impacts [70, 71]. It is important to perform
a thorough assessment of the initial trauma, as well as additional maneuvers
relevant to the patient’s injuries. When possible, the skin should be cleaned
of debris and body fluids to allow for improved visibility and accurate
assessment. Upon initial inspection of the face, providers should document
hemorrhage, visible fractures, asymmetry, bruising, and swelling. Any
wounds should be palpated and explored to estimate the depth and extent
[69]. If there are underlying fractures, the resultant asymmetry is not always
detected at first glance, and the face should be palpated diffusely to identify
bony step-offs, instability, and irregular contour. The location and extent of
bone fractures/losses, in addition to dentoalveolar injuries, are noted at this
time [68].
Cranial nerves are assessed to the best possible extent, although this can
be difficult in patients who are not fully conscious and/or have diffuse facial
lacerations. Ocular examination is always performed to assess pupillary
reflexes and examine the anterior chamber. In conscious patients, additional
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information can be obtained from the ocular exam, such as visual acuity,
visual field testing, light perception, and extraocular movements. Whenever
injury to the eye or surrounding structures is suspected, an ophthalmologic
consultation should be obtained [53, 69]. If there are indications of
neurological deficits and/or TBI, the patient should be admitted and
assessed using serial neurological examinations, and facial reconstruction is
contraindicated until the patient is stabilized [72]. However, it should be
noted that fractured bone is best repaired within a 2-week window for
optimal outcomes [73].
High-resolution computerized tomography (CT) is the favored imaging
technique for craniofacial injury, as it allows for three-dimensional
formatting and surgical planning. Photographs should be taken with patient
consent to compare and assess the postsurgical appearance [72].
Generally, isolated soft tissue wound repair should be performed as
soon as possible to allow for optimal postoperative results. If the wound
repair is delayed due to the prioritized treatment of additional severe injury,
the risk of infection is increased as with all open wounds. In addition, facial
swelling can increase in the days following initial trauma and may impede
accurate estimation and closure of the wound borders [73, 74]. Repair of the
underlying osseous structures and more superficial tissues are ideally
combined in one surgery, although this does not usually work for gunshot or
high-velocity blast injuries due to the required tertiary healing and
debridement [75–77].
The respective order of facial trauma repair follows the general
guidelines listed below [53, 69, 78]:
1.
Wound debridement and primary closure of tension-free wounds.
2. Fixation and reconstruction of the osseous craniofacial skeleton.
(a)
Open reduction internal fixation (ORIF) to augment and stabilize
intact fractured bone with minimal deficits.
(b) Bone reconstruction with non-vascularized or vascularized bone
grafts to repair bony gaps or large deficits.
(i)
Note: Temporary bridging of large osseous deficits is
performed as a last resort when bone reconstruction is not
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feasible.
3.
Soft tissue reconstruction using flaps or advanced skin repair
performed to cover exposed subcutaneous tissues.
(a)
May be performed prior to future skeletal augmentation surgeries
to promote optimal wound healing and aesthetic outcome.
4.2 Craniofacial Burns
Patients who present with burn injuries to the face and scalp should be
assessed thoroughly, especially when smoke inhalation or airway
compromise is indicated. The nature of the burn should lead the
consultation, as the various etiologies impose different risks to patients.
Thermal burns are most common (e.g., fire), and other causes include
exposure to electrical energy, radiation, and chemicals. Primary
interventions are usually performed by EMS or trained bystanders, who
ensure scene safety and limit further injury by removing the patient and/or
source of the burn. When the victim’s clothing can be safely removed
without taking skin with it, providers should remove as many layers as
possible [12, 79].
In the emergency department, the physician will evaluate the airway, as
well as the patient’s breathing capabilities. Mucosal edema in the airway
occurs shortly after the injury is sustained and can progress in severe cases
to airway obstruction. The ATLS (Advanced Trauma Lift Support)
guidelines list indications for intubation with severe burn trauma, although
some facilities observe variations of these guidelines to avoid unnecessary
intubation [79, 80] (Table 1).
Table 1 Indications for intubation from the ATLS and Denver criteria
ATLS indications for intubation Denver criteria
Airway obstruction: hoarseness, stridor, sternal
retraction, accessory respiratory muscle use
Stridor
Respiratory compromise: diminished/decreased
ventilation, low tissue oxygenation, inability to
clear mucus/secretions in the respiratory tract
Respiratory distress, hypoxia, and/or
hypercarbia
Deep facial damage and/or damage to oral cavity Upper airway trauma observed with
laryngoscopy
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ATLS indications for intubation Denver criteria
Injury to 40–50% of total body surface area Full-thickness facial burn injury
Diminished/loss of consciousness Changes in mentation (cognition, mood,
behavior)
Presence of mucosal edema in the airway and/or
difficulty swallowing
Swelling observed with laryngoscopy
Required patient transfer to specialized facility
when airway compromise is suspected and/or
intubation cannot be safely performed en route
Additional indications: singed facial hair,
hemodynamic instability (unstable/abnormal
blood pressure), suspected smoke inhalation
Additional studies highlight the emphasis of using flexible
laryngoscopy and bronchoscopy as an improved diagnostic tool for airway
damage, and this technique should be incorporated into the workup when
inhalation injury is suspected [81, 82]. In the absence of observed airway
damage (seen most frequently with thermal injury or particulate matter),
respiratory distress and/or hypoxia may be indicative of poisonous gas
inhalation [83].
The total body surface area (TBSA) is measured to assess how much
surface area has been damaged, using the patient’s hand and fingers to
represent 1% TBSA or the rule of nines. Providers may refer to the Lund
and Browder chart for a more accurate assessment, although computeraided models provide greater reliability and accuracy [84] (Figs. 6 and 7).
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Fig. 6 Rule of nines [85]
Fig. 7 The Lund and Browder chart provides a more detailed assessment of TBSA [85]
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Depth of injury, appearance, and level of pain can indicate whether the
patient has sustained superficial, partial-thickness (superficial or deep), or
full-thickness burns. Superficial burns incurring epidermal damage do not
usually require significant reconstruction or fluid replacement. Penetration
of injury to the dermis and sub-dermal tissues (as seen with partial- or fullthickness burns) results in fluid loss and life-threatening dehydration in
severe cases. The TBSA of partial- and full-thickness burn injuries is
calculated to determine recommended volume for fluid resuscitation [86].
Especially with facial burn trauma, a thorough assessment of the eyes,
periorbital area, and ears is indicated. Fluorescein slit-lamp examination is
performed to examine the corneal integrity after removal of contact lenses
and thorough rinsing of the eye. When any orbital or periorbital trauma is
noted, an ophthalmologic consult should be obtained. Otoscopy is
performed to assess the integrity of the tympanic membranes (ear), and the
structural cartilaginous involvement is documented. Patients who have
sustained multi-factorial traumatic injury, life-threatening tissue damage, or
airway damage are indicated for more invasive imaging (e.g., CT scan) and
laboratory assessment at initial presentation [12].
In the case of electrical burns, the outward appearance is not a good
indicator of potential internal damage, although it is important to locate the
current entry and exit wounds. Depending on the current path through
internal tissues and organs, patients may have underlying fractures, cardiac
arrhythmias, rhabdomyolysis, and/or compartment syndrome. This
necessitates additional diagnostic assessment with X-ray, ECG, continued
cardiac monitoring, and baseline laboratory samples at admission [87, 88].
The variable presentation of electrical burns is shown in Figs. 8 and 9.
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Fig. 8 An illustration of full-thickness tissue damage with evisceration and bowel trauma secondary
to severe electrical burn injury [90]
Fig. 9 The entry and exit wounds in a patient who experienced a low-voltage electrical burn [89]
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Patients who have undergone severe electrical burns may have
underlying muscular necrosis, indicating fasciotomy (removal of the
superficial muscular connective tissues) to reveal the integrity of the tissues
below. When this is not performed in a timely manner, patients are at
increased risk of acute kidney failure, limb loss, and severe infection [80].
When patients present with burns secondary to chemical exposure, the
airway integrity should be confirmed as with other burn etiologies, although
special consideration should be given to the potential inhalation of
aerosolized chemicals. Patients with extensive chemical burns may
experience severe metabolic disturbances with a devastating impact on
circulation and tissue perfusion, necessitating a thorough physical exam and
baseline laboratory testing. It is important to obtain a thorough history of
the present trauma, which should include the chemical composition,
mechanism of injury, quantity and concentration, and duration of exposure
[91].
Patients should be treated immediately to reduce the extent of damage,
beginning with chemical removal (ideally at the scene of injury). Thorough
irrigation with water should be performed as soon as possible to reduce
severity of tissue damage and maintain a cutaneous pH of 5–11, which may
require 2h of continuous tissue rinsing [92–94]. These burns may present
as superficial despite extensive deep tissue necrosis, although assessment of
microcirculation and comparison of unaffected and affected skin
temperature can assist with depth assessment. Serial depth assessment is
indicated to assess the progression of damage, although deep trauma is
assumed with inability to confirm depth of injury. Necrotic tissues should
be debrided and/or surgically excised as soon as possible, and patients are
referred to specialized trauma centers to stabilize severe metabolic
disturbances and correct extensive tissue losses with reconstructive surgery
[94–96].
The chief concerns of local wound management secondary to severe
burns are infection and tissue dessication. A few hours after the injury, the
wound is generally considered sterile with minimal bacterial colonization.
Over the course of several days, damaged skin is susceptible to greatly
increased bacterial number and virulence, which can incur damage and
infection to adjacent healthy tissue. This is attributed to damaged
vasculature and resultant limitation in the immune system
response/signaling and delivery of systemic antibiotics [97–99].
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