Blunt Neck Trauma and Laryngotracheal Injury

TITLE: Blunt Neck= Trauma and Laryngotracheal Injury
SOURCE: Grand Rounds Presentation, University of Texas Medical Branch (UTMB= ),
Dept. of Otolaryngology
DATE: December 17, 2010
RESIDENT PHYSICIAN: Susan Edionwe, MD
FACULTY PHYSICIAN: Farrah Si= ddiqui, MD
DISCUSSANT: Farrah Siddiqui, MD
SERIES EDITOR: Francis B. Quinn, Jr., MD
ARCHIVIST: Melinda Stoner Quinn, M= SICS

"This material was prepared by reside= nt physicians in partial fulfillment of educational requirements established f= or the Postgraduate Training Program of the UTMB Department of Otolaryngology/= Head and Neck Surgery and was not intended for clinical use in its present form.= It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to= its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and sho= uld not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion."

Introduction

Blunt neck trauma and its associated injuries is a clinically important situation that can have devastating results if unrecognized. This serves as a review of blunt neck trauma from its injurie= s to evaluation, management, and prognosis.

Anatomy of the Neck and Larynx

The neck is such that it is bordered posteriorly by = the spine, anteriorly by the larynx/trachea, superiorly by the head, and inferi= orly by the chest. It contains several structures including musculoskeletal structures such the vertebrae, the cervical and strap muscles, various tendons and ligaments, and the hyoid bone. It also contains very impor= tant neurologic structures including the spinal cord, cervical roots including t= hose of the phrenic nerve and brachial plexus, the recurrent laryngeal nerve, and stellate ganglion. The vasculature of the neck is important not only in reg= ards to its purpose but as surgical landmarks. The vasculature of the neck includes the more often noted, carotid arteries and the jugular veins. The vertebral arteries and veins along with the brachiocephalic vasculature, although less mentioned, remain part of the vasculature of the neck. The neck also contains glandular struct= ures like the thyroid, parathyroids, and submandibular glands as well as visceral structures such as the thoracic duct, esophagus, pharynx, and trachea.

Another visceral structure of the neck is the larynx= . The larynx is the narrowest part of the airway; it houses the phonatory apparat= us and protects the airway from aspiration during swallowing. It is protected = by the mandible superiorly, the sternocleidomastoid laterally, cervical spine posteriorly, and the sternum inferiorly. It consists of three cartilages: the thyroid cartilage, cricoid cartilage, and the arytenoids all made of hyaline cartilage. The epiglottis is also part of the lary= nx but is made of fibroelastic cartilage. The thyroid cartilage is suspended between the hyoid bone via the thyrohyoid membrane and the sternum; it is also secured by the extrinsic muscles of the larynx. The thyroid cartilage arti= culates with the cricoid via the cricothyroid joint and the cricothyroid membrane.<= span style=3D'mso-spacerun:yes'> Paired hyaline structures called aryten= oids sit posteriorly on the cricoid. Promin= ences called vocal processes project from the arytenoids and serve as the attachm= ent for the vocal ligaments and assist vocal cord movement. Likewise, the intrinsic muscles of the = larynx alter the position, shape, and tension of the vocal folds.

Zones of the Neck

Although the zones of the neck are used to classify penetrating neck injuries, they should be review when discussing neck anato= my. There are three zones of the neck labeled numerically. Zone three is= the highest zone in the neck and is bordered by the skull base superiorly and the angle= of the mandible inferiorly. Zone two = extends from the angle of the mandible to the cricoid cartilage. Zone one extends from the cricoid carti= lage to the thoracic inlet. Management = and evaluation of penetrating injuries to the neck are mediated by the zone of injury.

Injuries of Blunt Neck Trauma

Blunt neck trauma (BNT) is known to be rare occurring about 5% of time of all neck traumas. There are various sources of blunt ne= ck trauma and each is associated with pattern of injury. The most common mechanism of BNT is mot= or vehicle collisions. These injuries= are associated with rapid acceleration or deceleration and a direct blow of the= anterior neck on the steering column or dashboard; hence it is also known as padded = dash syndrome. This leads to crushing o= f the trachea usually at the cricoid ring as well as possible compression of the = esophagus against the vertebrae.

Clothesline injuries are often associated with major= blunt trauma to the neck. These injuries= occur in typically young adolescent patients who ride motorcycles, all-terrain vehicles, or snow mobiles when they strike a stationary object such as a wi= re fence or tree limb. Clothesline in= juries can also occur in high contact sports. With these injuries, a large amount of energy is transferred to a sm= all neck and this leads to crushed laryngeal cartilage and frequently cricotrac= heal separation. With cricotracheal separation, the injured airway is held together by intervening mucous membranes.

Strangulation is a form of BNT that consists of homi= cidal strangulation either via ligature suffocation or manual choking, suicidal strangulation (hanging), and postural asphyxiation seen in children when the neck is placed over an object and the body weight produces compression. With strangulation, a steady compressive force is applied to the neck and can be associated with delayed laryngeal edema. Homicidal strangulation injures via carotid artery occlusion or caro= tid sinus reflex death, a disputed mechanism of death in which manual stimulation of = the carotid sinus is believed to cause strong glossopharyngeal nerve impulses leading to terminal cardiac arrest. In suicidal strangulation, there is an association with laryngotracheal separation and neurovascular injuries. The mechanism of action for suicidal strangulation is the following: pr= essure is applied to jugular veins leading to obstruction of venous return from the brain. This results in venous cong= estion in the brain and loss of consciousness ensues. The patient falls with his or her full w= eight against the ligature and the trachea is compressed, restricting airflow to = the lungs. This results in irreversible asphyxiation or death.

Esophageal injuries

In blunt trauma, the mechanism of esophageal injury = is caused by compression of the cornu of the thyroid cartilage or other parts = of the laryngeal cartilage against the cervical spine. This leads to the laceration of the pharyngeal mucosa. This is infrequently associated with BNT and is present 3%-14% of the time with laryngeal fractures. Symptoms of injury include: dysphagia, odynophagia, hematemesis, hemoptysis, bloody saliva, tachycardia, fever. Subcutaneous emphysema can be seen on imaging. A gastrografin study = is recommended as first line. If nega= tive, barium swallow is recommended as it has a greater sensitivity of 90%. Evaluation also includes endoscopy, eit= her rigid &/or flexible endoscopy. Weige= lt et al reported 100% of esophageal injuries were found with BS and rigid endosc= opy and other studies have shown that 100% of perforations were found with a combination of flexible and rigid endoscopy. After the injury has been isolated, treatment ranges from observatio= n, if clinical exam is benign, to surgery. Surgical intervention involves debridement with a two-layered primary closure +/- muscle flap over the suture line to prevent TE fistula and intr= a-operative drain placement.

Cervical Spine Injuries

Cervical spine injury is highly associated with BNT.= This can result from severe hyperextens= ion during rapid acceleration or deceleration in motor injuries. Also, signific= ant cervical spine and spinal cord damage can occur in hangings that involve a = fall from a distance greater than the body height. Cervical spinal disruption subsequent to strangulation is almost uniformly fatal. Symptoms of this kind of injury include = hemiplegia, quadriplegia, CN deficits, changes of sensorium, Horner’s syndrome secondar= y to disturbance of stellate ganglion, and neurogenic shock. Evaluation of this injury includes AP a= nd lateral cervical radiography plain films and CT scan. Management of this injury should includ= e a neurosurgery consult. From the ENT standpoint, cervical stability is important to establish especially in the event of tracheostomy placement or endoscopy. Cervical spine precautions including cervical spine immobilization and supine placement of the patient= on a backboard are necessary.

Vascular Injuries

Vascular injury occurs in 1-3% of all BNT and is associated with 20-30% mortality. = It mostly occurs with motor vehicle collisions. Rapid deceleration causes hyperflexion, hyperextension, and rotation= of the neck. As a result, the vascular structures are stretched over the cervical spine leading to shearing forces= on the vessels and subsequent intimal tears in the vessel wall. “Hard signs” of injury include bruits o= r thrills, expanding or pulsatile hematomas, pulsatile or severe hemorrhage, and pulse deficits. “Soft signs” include hy= potension, shock, stable hematoma, and CNS/PNS ischemia. Of note, often blunt vascular injury initially manifests in the form of acute ischemic stroke and can be delayed in onset. Classic presentation includes a neurologically intact pat= ient who develops hemiparesis after a high-speed MVC. Evaluation by four-vessel angiography remains the gold standard given its sensitivity of 99%. CT angiogram is 68% sensitive and 67% sp= ecific and MRA is 75% and 67% for specificity and sensitivity, resp. These modalities can be used as adjunct= s to evaluation but are not first-line. Duplex US have a sensitivity 90-95% but only with a skilled technici= an. Managing vascular injury depends on the= extent of injury. Grading systems like th= e Denver grading sc= ale for blunt carotid artery injury can provide a prognosis and treatment for this injury. In general, surgical repai= r is preferred over ligation and primary repair is preferred over grafting.

Laryngotracheal injuries

Epidemiology

The incidence of laryngotracheal injuries is such th= at it is rare. According to some sources= it occurs in 1 out every 5,000-47,000 adults and in 0.05% of trauma admissions= in children. The incidence can be as = high as 1 in 445 in major urban trauma centers. Jewett et al found an incidence of 1:137= ,000 in population-based, time series analysis of external laryngeal trauma in 11 states. Although not prevalent, it is second to only intracranial injury as= the most common cause of death among patients with head and neck trauma and is a clinically important injury. In fa= ct, Line et al reported that 112 (65%) of 171 blunt neck trauma patients in the= ir series did not survive. About 60% of all external laryngotracheal traumas a= re due to blunt neck trauma and in this setting there is a concern for these injuries to be overlooked in situations of multitrauma (maxillofacial, cervical, and intracranial injuries). The final common pathway of laryngotracheal injury is compressive force on the larynx. This is modified by the de= gree of laryngeal calcification present.

Clinical Presentation

The most common presenting symptom for laryngotrache= al trauma is hoarseness. Juutilainen = et al found that in a review of 33 cases of external laryngeal trauma, hoarseness= was the presenting symptom in 85% of cases (28 patients). This finding is consistent with other studies. Ot= her presenting symptoms include: dysphagia, pain, dypsnea, hemoptysis, and symp= toms of airway obstruction such as stridor or tachypnea. Other signs include drooling and cervic= al subcutaneous emphysema or crepitation. As for crepitation/subcutaneous emphysema, interestingly, Goudy et al found that of 236 patients admitted w= ith aerodigestive tracheal injury or subcutaneous emphysema, only 8% (19 patien= ts) were identified with cervical emphysema/crepitations thought to be caused by aerodigestive injury, thus indicating that this is a low yield sign of laryngotracheal injury. In additio= n to crepitations, physical examination reveals skin abrasions, bruising, laryng= eal tenderness, and distortion of the anterior neck anatomy.

Examination/Classification

A systematic and concise approach is needed to accur= ately identify the injuries to the laryngotracheal system. The mode of injury should be determined= – either blunt or penetrating. The s= ite should be identified as supraglottic, glottic, or subglottic. The structures injured should be assess= ed such as hyoid bone, thyroid cartilage, cricoid cartilage, or arytenoids injury. As per Cumming’s Otolaryng= ology: Head & Neck Surgery, the systematic approach proposed by the author includes an assessment of the laryngeal framework as stable, unstable, or potentially nonviable and an assessment of the mucosa as intact/minimal injured, injured, or massively injured. The vibratory apparatus is described as intact or injured and the laryngotracheal junction is described as intact or with any degree of separ= ation. A more commonly referenced classificati= on of laryngotracheal injury is the Schaefer-Fuhrman classification which separat= es the extent of injury into five groups. Group one includes minor endolarynge= al hematoma or lacerations, no laryngeal fracture, and is treated with observa= tion and humidified O2. Groups 2, 3, an= d 4 presents with symptoms of airway compromise; however, group 2 involves edema and mucosal disruption and is treated with a tracheostomy to secure the air= way along with panendoscopy. Group 3 injury presents with massive edema and inj= ury that involves cartilage exposure and vocal cord immobility. Management of these patients includes tracheostomy along with exploration and repair. Group 4 injury involves massive edema, exposed cartilage, disruption= of the anterior commissure and unstable fractures. The injury is so severe that stent placement is needed in addition to tracheostomy, exploration, and rep= air. Group 5 presents with cricotracheal separation and requires urgent tracheostomy along with exploration and repair. Other similar classificati= ons exist such as the Lee Eliashar classification and the proposed Legacy Emmanuel Hospital and Health Center laryngeal injury classification that takes into account CT findings.

Evaluation of Laryngotracheal Trauma: Securing an Airway

As these injuries in the setting of trauma, laryngot= racheal injury at times may be addressed during the primary survey of assessing air= way, breathing, and circulation. It is a priority to establish an airway with cervical spine protection as indicated= . Tracheostomy preferred to intubation because intubation can exacerbate laryngeal injury = with the feared outcome being precipitation of total airway obstruction. Further, it is difficult to perform in = the presence of concomitant maxillofacial injuries in patients with immobile ne= cks. However, if it is to be performed such = as in patient with signs of acute or impending respiratory distress, it is recommended it be done by the most experienced medical professional.

Imaging

High resolution computed tomography is performed in = all patients with laryngotracheal injuries once their airway is secure. Given advances with CT, such as multide= tector row CT (MDCT), high resolution can be obtained in shorter scan times. Cut thickness for imaging in patients w= ith concerns for laryngotracheal trauma should not exceed 1mm in thickness. Robinson et al in their review of MDCT = also recommend obtaining multiplanar reconstructions as it allows for confirmati= on of fractures lines and fragments as well as suspected dislocation on transv= erse scans. Further, horizontal fractur= es are difficult to appreciate on as the run parallel to the acquisition plan of t= he CT scan and would be missed without review of coronal and sagittal reconstructions. It is necessary to review the image under soft tissue windows to evaluate for mucosal or vocal cord asymmetry and swelling and bone windows. IV contrast is not necessary unless there are concerns for vascular injury.

The thyroid cartilage is most commonly affected in laryngeal fractures. Robinson et al found that of the 41 scans they reviewed, 33 thyroid fractures were found, = 23 of which were isolated fractures. = 19 cricoid fractures were present and only 1 arytenoid fracture was identified. They also discuss that horizontal fractures often cross the midline and usu= ally occur with supraglottic soft tissue injury. Isolated fractures of the upper and lower horns of the thyroid were uncommon. Further, they discuss th= at, as expected, visualization of a fracture is easier in ossified cartilages and = with displaced fractures. Of note, the= y did find that cricoid fractures are typically bilateral and cause airway collap= se should the mobile fragment of cricoid retropulse into the airway.

As discussed by Robinson et al, radiographically, fractures can be classified by the Schafer-Fuhrman classification but the limitation is the scheme requires endoscopic evaluation. In their series, they classified their patients into 8 with Schafer grade 2 classifications, 26 with grade 3 classifications, and 7 with grade 4 classifications. They do discuss the purely radiologic classification proposed by Ogura et al which is recommended in radiologic text. This classification has five levels. Level A includes soft tiss= ue injuries with or without non-displaced fractures. Level B involves supraglottic fracture = and injuries. Level C involves glottic injuries which includes midline vertical thyroid fractures or cricoid fract= ures and injury of the vocal cords. Level D is cricoid fractures with varying degrees of airway obstruction and level E involves tracheal fractures to complete transaction injuries.

Flexible fiberoptic nasolaryngoscopy

There is a role for fiberoptic nasolaryngoscopy for a preliminary assessment of the extent of trauma and vocal cord mobility in stable patients. Care should be ta= ken during this exam to not exacerbate compromise to the airway. Clinical findings seen on endoscopy inc= lude deformities of the larynx, swelling, lacerations, exposed cartilage, complete or partial vocal cord fixation indicative of RLN injury or dislocation of the cricoarytenoid joint, and hematoma. Of note, prior to any manipulation of the neck for positioning, the examiner should be aware of c-spine injury and this should be ruled out.

Conservative management

Conservative management is indicated in patients tha= t fall under group 1 and some in group 2 of Schafer’s classification and involves = observation. Specifically, observable conditions inc= lude: edema, small hematomas with intact mucosal coverage, small glottic or supraglottic lacerations without exposed cartilage, and single non-displaced thyroid cartilage fractures in a stable larynx. The following should be implemented: admission to the ICU for strict monitoring and some sources recommend serial flexible nasolaryngoscopy examinations. Humidified oxygen should be at the bedside and serves to help prevent crust formation in the presence of mucosal damage and transient cil= iary paralysis. The patient’s head of b= ed should be elevated to reduce swelling in addition to steroids. Anti-reflux precautions are always recommended as they serve to prevent scar formation = in the setting of mucosal injury. Prophylactic broad spectrum antibiotics shou= ld be given if laryngeal mucosa injury has occurred.

Surgical options for laryngotracheal repair

Situations requiring surgical repair include: lacera= tions involving the free margin of the vocal fold, large mucosal lacerations, exp= osed cartilage, multiple and displaced cartilage fractures, avulsed or dislocated arytenoids cartilages, and vocal fold immobility. The ultimate long-term goal is to resto= re laryngeal function including phonation, protection from aspiration, ventilation, and deglutition to as near baseline as possible. It is recommended that all surgical pat= ients receive panendoscopy intraoperatively for a detailed examination of the injury befo= re surgical repair. Direct laryngosco= py, bronchoscopy, and esophagoscopy are integral in diagnosing aerodigestive in= jury and should be done after an airway is secured, specifically once the tracheostomy is done.

As per Cummings Otolaryngology: H= ead & Neck Surgery, the indications for open laryngeal repair are as follow= s: injuries involving unstable fractures or comminuted fractures, cricotracheal separation, detachment of the anterior commissure, and mucosal disruption. = Other indications include fractures of t= he median or paramedian parts of the thyroid alae, cricoid fractures, and inju= ry involving vocal cord paralysis. The more conventional approach is an open procedure. Closed endoscopic reduc= tions are possible for injuries such as arytenoids dislocation or minimally displ= aced laryngeal fractures +/- stenting. However, there is limited experience with closed reductions; thus, m= ost procedures are done open. Thyrotomy or an anterior vertical laryngofissure = is the approach to open procedures involving intralaryngeal repair such as reapproximation/repair of fixed vocal cords or repairing endolaryngeal soft tissue lacerations or avulsions. T= his approach is begun by a horizontal skin incision made at the level of the cr= icothyroid membrane. Subplatysmal flaps are elevated superiorly to hyoid and inferiorly to the cricoid. The straps are separated at midline and retract laterally. The thyroid car= tilage is incised vertically at its midline. It is very important to enter at = midline rather than on either side of the anterior commissure as this adversely aff= ects repair. This is done by incising a= t the cricothyroid membrane and incising the mucosa superiorly under direct visualization. Of note, if a verti= cal fracture already exists near midline, this can be utilized as opposed to creating a vertical incision. The = endolarynx is entered through cricothyroid membrane and incision is extended superiorly through the anterior commissure to the thyroid membrane.

For procedures not involving intralaryngeal repair s= uch as plating a fracture, after splitting the strap muscles and exposing the thyr= oid cartilage and the cricoid, the perichondrium is incised at the midline and perichondrial flaps are raised on both sides of the fracture. Fractures can= be re-approximated using suture, wire, and plating. As opposed to suture and wire, plating = helps to not only approximate but helps to stabilize the fracture. This is beneficial as it is known that = motion of fracture fragments increases bleeding, hematoma formation, inflammation, and, thus, the likelihood or infection or scar. When plating, Ballenger’s Otolaryngology: Head and Neck suggests that paramedian fractures be plated using a four hole “box-type” plate around the fracture aka four point fixation. For midline fractures, consideration must be made for the curvature of the thyroid cartilage anteriorly. Four point fixation is= still recommended. As for the cricoid, i= ts height will not allow for four point fixation, thus, a single horizontal plate is adequate to re-establish the integrity of the cricoid. The success of plating as been document= ed in literature. Sasaki et al evaluated= the efficacy of both MacroPore and Leibinger resorbable reconstruction plates i= n 3 adult male patients and found both plates to be equally easy to use. In addition, adequate skeletal stabilization was achieved, which allowed for e= arly phonation and respiratory function without long-term stenting. In Brazil, de Mello-Filho et al performed a retrospective study on the efficacy of adaptation plate fixation (APF) to repair the larynx. This group had no complications with the use of APF, and 19 out of 20 patients recovered their voices.

Cricotracheal Separation

Separation of the airway most often occurs between t= he cricoid and the trachea and at times between the rings of the upper trachea= . This condition is highly associated with clothesline injuries. As blunt neck trauma rarely yields clean cuts, cricot= racheal separation is usually associated with cricoid fractures and avulsion of the mucosa from the anterior surface of the posterior cricoid plate. This situa= tion can be grave given the possibility of a precarious airway and subsequent asphyxiation and is associated with a high mortality. When managing cricotracheal separation,= the airway is secured by tracheostomy. As the inferior portion of the trachea retracts substernally, it is mobilized into the surgical field with a crico= id hook or the like, a tracheostomy is performed, and a small ET tube is placed through the tracheostomy for ventilation during surgery. Primary re-anastamosis proceeds from pos= terior to anterior with a combination of 3-0 absorbable and non-absorbable suture. If the cricoid is intact a= fter the injury, only the mucous membrane needs to be repaired primarily with absorbable suture. Tension should = be distributed away from the anastamosis by placing non-absorbable sutures from the superior cricoid to the inferior portion of the first or second tracheal ring. If the cricoid is fractured, internal fixation of the cricoid cartila= ge should occur first as the strength of the repair is limited by stability of= the cricoid cartilage. Stenting may be considered given the extent of injury. Avascular and damaged tissue should = be resected. Of note, cricotracheal separation is highly associated with recur= rent laryngeal nerve injury. If fact, i= n a study by Couraud et al where 19 laryngotracheal disruption patients were studied, it was found that 14 of the patients have bilateral RLN injury and= 4 had unilateral RLN injury. Mucosa = was retracted in all patients to expose cricoid cartilage.

Exposed cartilage

Covering exposed cartilage – mucous membrane, dermis, STSG; responsible for granulation tissue and scar formation. Unfortunately, this graft wound heals be secondary intent and the risk of scar formation is greater than primary clo= sure of innate lacerated mucosa over the exposed area. Mucous membranes closely = resemble the normal endolaryngeal epithelium but use of the graft is associated with high donor site morbidity and the need to enter the mouth to harvest graft.=

Endolaryngeal stenting

Endolaryngeal stenti= ng is indicated when extensive lacerations involving the anterior commissure are present as it is used to prevent webbing of the anterior commissure in case= s of bilateral vocal cord epithelial loss. It is also indicated with multiple cartilaginous fractures that cannot be stabilized adequately with open reduction. However, it is controversial given it can be a source of mucosal inj= ury and its placement is associated with an increased risk of infection and granulation tissue formation. Its purpose aside from prevent webbing, is to stabilize the internal configurat= ion of the larynx. It should be fixed = in a fashion that it moves with the larynx during swallowing and can be accessed endoscopically. Securing this appa= ratus is described as passing a suture through the stent and larynx at level of laryngeal ventricle and at cricothyroid membrane and tying it over buttons = over the skin. The stent is usually lef= t in place for 10-14 days and removed early to avoid granulation tissue formatio= n.

Post op care

The guidelines for post op care are very similar to = that of conservative management. The pa= tient should be instructed to voice rest for 48-72hrs and anti-reflux and prophylactic antibiotic precautions should be given to prevent scar formati= on from irritation or infection. The = head of bed should be elevated to aid swelling and early ambulation should be encouraged. If stents have been pl= aced, it is recommended they be removed in 10-14 days so as to not contribute to mucosal irritation/injury with subsequent scar formation. Regular endoscopic exams should be perf= ormed to assess recovery. Of note, in patients with cricotracheal separation, neck flexion for 7 days in is recommended to prevent traction on the anastamosis. As for diet, it is recommended a nasogastric tube be placed intraoperatively until PO intake is safe. Tracheal care is always necessary given tracheostomy placement.

Complications and Long-term Management

Granulation tissue is the most common complication o= f not only laryngotracheal injury but surgery. The best mode of cure is prevention when possible by meticulous prim= ary closure and covering exposed cartilage. Endolaryngeal stent use should be limited to groups 4 and 5 of the Schafer classification and should be removed as soon as indicated. Other complications include laryngeal a= nd tracheal stenosis which can be treated with surgical repair or dilatation.<= span style=3D'mso-spacerun:yes'> Anterior and posterior glottic webbing = may also occur from injury or surgery and can also be managed surgically. Persistent vocal cord immobility may re= sults from RLN injury or cricoarytenoid joint separation. Endoscopic evaluation, either rigid or flexible, should be employed and vocal cord immobility should be managed according to etiology.

Follow-up after injury and surgery is recommended fo= r at least 1 year to evaluate for a combination of laryngeal stenosis, dysphonia, aspiration, both structural and neurovascular injuries, and monitoring for recovery of vocal cord paralysis. = Of note, procedures to correct vocal cord immobility can be done after 9-12mos= of observation with the possibility of full recovery. In the study by de Mello-Filho et al, af= ter 3-108 months of follow-up with 20 patients, ranging from grade III-V of the Schafer’s classification for laryngotracheal trauma, 19/20 reported good ai= rway and 18/20 reported fair to good voice outcome. All patients with tracheostomy placement were decannulated. As this and others studies have demonst= rated, outcome of patients with laryngeal trauma who receive prompt treatment is favorable.

Special Considerations: Pediatric Laryngotracheal Trauma

Although blunt neck trauma is not co= mmon in children, laryngotracheal injury is most commonly related to BNT when it does occur in children. As opposed= to adults, the most common cause of BNT and subsequent laryngotracheal injury = is bicycle accidents and falls. Anato= mically, the larynx in children is situated high in the neck and protected by the mandible. In neonates, it lies at = level C3 and starts to descend during the first 3 years of life to its final adult position at level C6. The high rid= ing larynx in children serves as protection. Further, the pediatric larynx has a higher amount of elasticity comp= ared to adults and is, thus, less susceptible to laryngeal fractures. In addition, the cricothyroid membrane = is narrower in children and less likely to have laryngotracheal separation. Conversely, as the submucosal tissues a= re loosely attached to the perichondrium in children. This increased the likelihood of soft t= issue damage, edema, and hematoma with possible airway obstruction.

Securing an airway in the setting of laryngotracheal trauma in the pediatric population is controversial. In children it is usually not possible = to perform an awake tracheostomy. Ho= wever, there is a fear of worsening laryngotracheal injury with intubation. The current recommendation, however, is= rapid sequence intubation followed by prompt tracheostomy.

Further, there is a very high association with cervi= cal spine injury and laryngotracheal trauma. It is quoted that this association can be as high as 50% of children with laryngotracheal trauma. As a result, it is important to have a low threshold of suspicion for cervical s= pine injury in this population and appropriate cervical spine stability and management should follow identification of injury.

Conclusion

Overall, blunt neck trauma is a medical situation th= at is uncommon but associated with very clinically important. It is important for otolaryngologists t= o stay aware of the evaluation and management of this situation

*****

Discussant’s Remarks – Dr. Siddiqui on Laryngotr= acheal Injuries, Dec 16, 2010

Tha= t was a very good presentation, Dr. Edionwe, a very complete review of laryngotracheal trauma and blunt neck injury. You were very correct in highlighting the fact that in children you = have to worry about C-spine injuries. In fact, in neck trauma the C-spine is more commonly injured than the airway because the airway is in a more protected location. In any case, with all the subcutaneous swelling at times you do have to intubate children being very careful not to hyperextend the neck and cause even more injury to the C-spine.

In children with a high C-spine injury, they may have a vascular injury as well and it may not present itself as clearly as in an adult. The signs and symptoms may not be appar= ent if the patient is already in shock. = For this reason it’s important to get a CTA and to look at their neck vasculatu= re,

In adults, we have a very good algorithm that you presented that classifies all the different grades of injury allowing one to move towards more conservati= ve management, doing an emergency tracheotomy, or taking the patient to the O.R. In the patient with laryngotr= acheal injuries one should always go the = O.R. for a direct look. If you are plan= ning a tracheotomy, you always need to do a pan-endoscopy even if you have a CT scan. The CT scan will help you ou= t, but taking a good look yourself is always the best for it will show mobility of= the fragments, whether something needs to be plated or fixed or watched. It gives you a much, much better inform= ation about what’s going on.

*******

Discussant’s Remarks: Francis B. Quinn, Jr., MD

Doctor Siddiqui has given an excel= lent and up-to-date summary of the diagnosis and treatment of penetrating injuri= es of the neck, with emphasis on the wide range of approaches made possible by newer imaging techniques. She has pointed out that the earlier "zone" protocol may be soon overwhel= med by the more modern "selective" management strategies.<= /span>

The question of evaluating various series of cases is made complicated by the several mechanisms of injury as drawn from different cultures and environments. We note that 75% of South African pati= ents present with incised wounds, 50% of U.S. urban patients seek treatment for gunshot wounds, and our military casualties suffer wounds from low-velocity shell fragments, as well as high velocity small caliber rifle bullets, often accompanied by substantial loss of tissue.

Thus, reports of treatment results= should allow us to picture the biomechanics of injury, for as has been shown in previous Grand Rounds, the high velocity projectile creates instantaneous a= nd extensive tissue expansion with shearing stress leading to delayed devitalization and unanticipated late complications. (See References below.)

&nb= sp;

Further,= even low velocity (800 fps) bullets are known to tumble and fragment, causing ti= ssue injury far from the missile track. In contrast, stabbing or cutting injury causes tissue injury limited to the tr= ack of the weapon.

&nb= sp;

Doctor Siddiqui's presentation has shown us that the newer treatment methods have = laid upon faculty of resident training institutions the requirement to distill t= he reports of these methods into a doctrine suitable for the instruction of th= ose aspiring young surgeons under our direction, a doctrine which takes into account the local weapons culture as well as the technical and imaging supp= ort available.

REFERENCES<= /span>

<= span style=3D'font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-fa= mily: Symbol;mso-bidi-font-weight:bold'>· = http://www.utmb.edu/otoref/Grnds/GrndsInd= ex.html

<= span style=3D'font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-fa= mily: Symbol;mso-bidi-font-weight:bold'>· = Management of Penetrating Neck Trauma [Sep 5, 2002]

<= span style=3D'font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-fa= mily: Symbol;mso-bidi-font-weight:bold'>· = Penetrating Neck Trauma [Jan 27, 19= 99]

TITLE: Penetrating Neck Trauma=
SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds Presentation
DATE: January 26, 1999
RESIDENT: Herve’ J. LeBoeuf, M.D.
FACULTY: Francis B. Quinn, Jr., M.D.
SERIES EDITOR: Francis B. Quinn, Jr., M.D.

TITLE: Management of Penetrating N= eck Trauma
SOURCE: Grand Rounds Presentation, UTMB, Dept. of Otolaryngology
DATE: September 6, 2002
RESIDENT PHYSICIAN: Shashidhar S. Reddy, MD
FACULTY PHYSICIAN: Shawn Newlands, MD, PhD

SERIES EDITOR: Francis B. Quinn, Jr.,= M.D.

*****

Bibliography

1.&n= bsp; Rathlev NK et al. Evaluation and management = of neck trauma. Emerg Med Clin North Am. 2007 Aug;25(3):679-94, viii.=

2.&n= bsp; Quesnel AM and Hartnick CJ. A contemporary review of voice and airway after larynge= al trauma in children. The Laryngoscope. <= span style=3D'font-size:12.0pt;font-family:"Cambria","serif";mso-fareast-font-fa= mily: "Times New Roman";mso-bidi-font-family:Arial;color:windowtext;mso-bidi-font= -weight: bold;text-decoration:none;text-underline:none'>Volume 119, Issue= 11, pages 2226–2230, Nov= ember 2009

3.&n= bsp; Losek et al. Blunt laryngeal trauma in children: case report and review of initial airway management. Pediatr Emerg Care. 2008 Jun; 24(6):370-3.

4.&n= bsp; Srirompotong S et al. Total pharyngo-supraglottic separation following blunt neck trauma= : a case report. J Med Assoc Thai. 2009 Jul; 92(7):990-3.

5.&n= bsp; Goudy SL, Miller FB, Bumpous JM. Neck crepitance: evaluation and management of suspected upper aerodigestive tract injury. Laryngoscope. 2002 May;112(5):791-5.

6.&n= bsp; Aouad R, Moutran H, Rassi S. Laryngotracheal disruption after blunt neck trauma. = Am J Emerg Med. 2007 Nov;25(9):1084.e1-2.

7.&n= bsp; Levy DB, Gruber BS. Neck Trauma. Emedicine. http://emedicine.medscape.com/ artic= le/827223-overview

8.&n= bsp; Myers, et. al. Operative Otolaryngology, Laryngeal Trauma, 2^nd edition.= p 349-356.

9.&n= bsp; Bailey, B.J. Head and Neck Surgery-Otolaryngology. Laryngeal Trauma, J.B. Lippincot= t; Philadelphia. Ch = 68 vol. 1. 1998

10.&= nbsp; Sandhu GS, Reza No= uraei SA et al. Laryngeal and esophageal trauma. Cummings Otolaryngology Head and Neck Surgery.; 5^th edition. New York: Mosby Elsevier, 2010.Ch 70: 933-942

11.&= nbsp; Bell B, Verschuere= n E, Dierks E. Management of laryngeal trauma. Oral Maxillofacial Surg Clin N Am. 2008; 20:415-430

12.&= nbsp; Robinson s, Juutil= ainen M, Suomalainen A, et al. Multidetector row computed tomography of the injur= ed larynx after trauma. Semin Ultrasound CT MRI. 20009; 30:188-194

13.&= nbsp; Juutilainen M et a= l. Laryngeal fractures: clinical findings and considerations on suboptimal outcome. Acta Otolaryngol. 2008; 128:213-218

14.&= nbsp; Schaefer, S. D., T= he acute management of External Laryngeal trauma, a 27 year experience, Archiv= es of Otolaryngology Head and Neck Surgery., Vol 118, June 1992, 598-604.=

15.&= nbsp; Stierman K, Quinn, FB. Laryngeal Trauma, UTMB Dept. of Otolaryngology Grand Rounds Archive, October 06, 1999.

16.&= nbsp; Jewett BS, William SW, Rutledge= R. External Laryngeal Trauma Analysis of 392 Patients. Arch Otolaryngol Head N= eck Surg. 1999;125:877-880

17.&= nbsp; Line WS Jr, Stanley RB, Choi JH: Strangulation: A full spectrum of bl= unt neck trauma. Ann Otol Rhinol Laryngol 4:542-546, 1989.=

18.&= nbsp; de Mello-Filho FV, Carrau RL. The Management of Laryngeal Fractures Using Internal Fixation. Laryngoscope 110: December 200= 0=

19.&= nbsp; Sasaki CT et al. Efficacy of resorbable plates for reduction and stabilization of laryngeal fractures. Ann Otol Rhinol Laryngol. 2003 Sep;11= 2(9 Pt 1):745-50.

20.&= nbsp; Couraud L, Velly JF, Martigne C and N'Diaye M. = Post traumatic disruption of the laryngo-tracheal junction. European Journal of Cardio-Thoracic Surgery, Vol 3, 441-444.