Neck

David V. Feliciano and Gary A. Vercruysse

INTRODUCTION

One of the first reported cases of cervical trauma was in Homer’s Iliad when Achilles delivered a fatal lance blow to Hector’s neck, “where the clavicle marks the boundary between the neck and thorax.” This was portrayed by Peter Paul Rubens in about 1631 and hangs in the Museum Boymans-van Beuningen in Rotterdam, the Netherlands.¹ Treatment was first described by Ambrose Pare in the mid 16th century when he ligated the right carotid artery and jugular vein of a solider who suffered a bayonet wound. The patient survived, but was aphasic and developed a dense, left-sided hemiplegia.² The first successful treatment of a major cervical vascular injury did not occur until 1803 when Fleming aboard the HMS Tonnant ligated the common carotid artery of a sailor after a suicide attempt while at sea. The sailor made a prolonged, but complete recovery.^3,4 A similar case was reported by Eves of Cheltenham, England, in 1849.⁵

ANATOMY

Knowledge of the surface landmarks of the neck is important for optimal evaluation and management of cervical injuries.⁶ The defining borders of the neck encompass the area between the lower margin of the mandible and the superior nuchal line of the occipital bone and the suprasternal notch and the upper borders of the clavicles.

Palpable structures from the upper to lower border of the neck include the symphysis menti, which is where the two halves of the body of the mandible unite in the midline. The submental triangle, located between the symphysis menti and the body of the hyoid bone, is bounded anteriorly by the midline of the neck. Laterally, it is bounded by the anterior belly of the digastric muscle, and the mylohyoid muscle forms the floor. The body of the hyoid bone lies opposite the third cervical vertebra. The area between the hyoid bone and the thyroid cartilage is the thyrohyoid membrane, while the notched upper border of the thyroid cartilage is at the level of the fourth cervical vertebra. The cricothyroid ligament or membrane occupies the space between the thyroid cartilage and the cricoid cartilage, which lies at the level of the sixth cervical vertebra and the junction of the pharynx with the esophagus. The interval between the cricoid cartilage and the first tracheal ring is filled by the cricotracheal ligament. Moving inferiorly, the isthmus of the thyroid gland is at the level of the second, third, and fourth tracheal rings. The suprasternal notch can be palpated between the clavicular heads and lies opposite the lower border of the body of the second thoracic vertebra. The sternocleidomastoid muscles, which divide the sides of the neck into anterior and posterior triangles, can be palpated from sternum and clavicle to the mastoid process. The borders of the posterior triangle are the body of the mandible, the sternocleidomastoid muscle anteriorly, and the border of the trapezius muscle posteriorly, along with the clavicle inferiorly.

Posteriorly, the structures of the neck that can be palpated in the midline are the external occipital protuberance, the nuchal groove, and the spinous process of the seventh cervical vertebra (cervical spines 1–6 are covered by the ligamentum nuchae).

The platysma, a thin muscular sheet, is enclosed by the superficial fascia. Its origin is from the deep fascia that covers the upper part of the pectoralis major and deltoid muscles, and it inserts into the lower margin of the body of the mandible. It is the anatomic landmark that is often cited when determining whether a penetrating wound of the neck is superficial or deep. The potential for injury to a vital structure exists when this structure is penetrated.

Beneath the superficial sternocleidomastoid, strap, and trapezius muscles that envelop much of the neck, there are eight body systems that lie within or pass through the neck. Included among these are the following: (1) skeletal system (seventh cervical vertebra, hyoid bone); (2) nervous system (spinal cord and the glossopharyngeal [IX], vagus [X], spinal accessory [XI], and hypoglossal [XII] cranial nerves); (3) respiratory system (oropharynx, larynx, cervical trachea); (4) gastrointestinal system (oropharynx, cervical esophagus); (5) vascular system (common, internal, and external carotid arteries, vertebral arteries, internal and external jugular veins); (6) lymphatic system (thoracic duct); (7) endocrine system (thyroid and parathyroid glands); and (8) immune system (cervical extensions of the thymus).

ZONES

Penetrating wounds to the neck, particularly those that might involve cervical vascular structures, have been grouped into three separate zones since the original description by Monson et al. in 1969⁷ (Fig. 22-1). A minor modification suggested by Roon and Christensen in 1979 is not of clinical significance.⁸ Zone I is inferior to the clavicles and manubrium sterni and encompasses all structures in the thoracic outlet. Structures in this zone include the proximal common carotid arteries, vertebral arteries, right and left extrathoracic subclavian arteries, jugulo-subclavian venous junctions, crossover left innominate vein, thoracic duct, trachea, esophagus, spinal cord, proximal brachial plexus, and the vagus nerve. Operative exposure for injuries in Zone I mandates a median sternotomy with cervical extensions, high anterolateral thoracotomy, or a supraclavicular incision with claviculotomy or partial excision of the clavicle, so strong clinical evidence of vascular or visceral injury must be present prior to operation. Zone II is between the thoracic outlet and the angle of the mandible. Structures in this zone include the common carotid arteries and bifurcations, vertebral arteries, internal jugular veins, larynx and cervical trachea, cervical esophagus, spinal cord, and the vagus, spinal accessory, and hypoglossal nerves. Operative exposure for injuries in Zone II mandates an ipsilateral oblique incision along the anterior border of the sternocleidomastoid muscle or a high anterior cervical incision with oblique extensions for possible bilateral injuries. Zone III is between the angle of the mandible and the base of the skull. Structures in this zone include the internal carotid arteries, vertebral arteries, internal jugular veins, pharynx, spinal cord, and the facial, glossopharyngeal, vagus, spinal accessory, and hypoglossal nerves. Operative exposure for injuries in Zone III mandates subluxation of the temporomandibular joint with interdental wiring or vertical ramus mandibulotomy (to be discussed).

FIGURE 22-1 Zones of the neck. (From Monson DO, Saletta JD, Freeark RJ. Carotid vertebral trauma. J Trauma. 1969;9:987. Used with permission.)

PRESENTATION

Patients with penetrating or blunt trauma to the neck present with overt symptoms and/or signs, moderate or modest symptoms and/or signs, or they are asymptomatic without signs of aerodigestive or vascular injury. The presentation of a patient with overt symptoms or signs will vary depending on the zone of the neck involved. In Zone I a vascular injury from a penetrating wound may cause external hemorrhage from the thoracic outlet or intrapleural exsanguination. A penetrating wound in Zone II or blunt disruption of the cricotracheal junction secondary to a “clothesline” injury may lead to loss of the airway and early asphyxiation. Loss of the airway can occur secondary to the presence of a large hematoma from an injury to the carotid artery, as well. Active hemorrhage from either the carotid artery or internal jugular vein in Zone II can be external and lead to exsanguination or internal bleeding into an associated injury to the trachea, leading to aspiration and asphyxiation. While injures in Zone III are uncommon, exsanguination can occur from an injury to the internal carotid artery at the base of the skull.

Patients with modest or moderate symptoms or signs may present with complaints of hoarseness, dysphagia, or odynophagia and palpable crepitus suggestive of injury to the larynx, trachea, or esophagus. The other presentations in this group are proximity of penetrating wound or blunt contusion to the carotid sheath and/or a stable hematoma suggestive of injury to the carotid artery or internal jugular vein.

An asymptomatic patient will have penetration of the platysma muscle by a gunshot or knife wound or bruising or contusion after blunt trauma, but have no symptoms or signs of injury to the aerodigestive tracts, cervical vessels, the spine, or the spinal cord.

Management of the patient depends on presentation. Overtly symptomatic patients have “A, B, or C” problems on the primary survey as taught in the Advanced Trauma Life Support course, and immediate resuscitation is performed in the emergency center or operating room (see below). Patients with modest or moderate symptoms or signs undergo a diagnostic evaluation referable to the suspected system injured or one that encompasses the aerodigestive and arterial systems. Asymptomatic patients are discharged, admitted for observation, or, in some centers, undergo a limited radiologic evaluation (i.e., cervical computed tomography [CT]).

MANAGEMENT OF PATIENTS WITH OVERT SYMPTOMS OR SIGNS

In patients with exsanguinating external hemorrhage from the thoracic outlet or the lower anterior neck, usually from a penetrating wound, blind finger compression of the bleeding vessel through the skin defect is appropriate in the emergency center (Fig. 22-2). If this is unsuccessful, rapid enlargement of the skin defect with or without local anesthesia is performed. Once again, an attempt is made to compress the bleeding vessel with two or three fingers inserted through the enlarged skin defect. An unsuccessful attempt is followed by tight packing of the area using 3- or 4-in gauze and rapid transport to the operating room. The operative incision will depend on the track of the wound, whether or not manual compression or packing has controlled the bleeding, and the patient’s hemodynamic status. For example, a wound thought to involve the proximal common carotid artery at the base of the neck rather than more proximally in the mediastinum is exposed with the standard anterior oblique invasion on the side of injury. An unstable patient with continuing hemorrhage from the outlet or presumed intrapleural exsanguination should undergo a high anterolateral thoracotomy (fourth intercostal space above the male nipple) on the side of the injury to allow for direct proximal clamping or pack compression of the injured vessel in the thoracic outlet. If the wound is on the right side of the thoracic outlet and the patient is profoundly hypotensive, the sternum is divided transversely and a standard (below the nipple) left anterolateral thoracotomy is performed, as well. This will allow for cross-clamping of the descending thoracic aorta to increase perfusion to the coronary and carotid arteries as resuscitation and vascular repair or ligation are accomplished.

FIGURE 22-2 Algorithm for management of patients with overt symptoms or signs.

In Zone II a penetrating wound may cause impending asphyxiation from a major injury to the trachea (suggested by a continuing air leak from the entrance site). The skin defect is rapidly enlarged with or without local anesthesia, and an endotracheal tube is inserted through the enlarged track following the air bubbles into the distal end of the trachea once it is visualized (Fig. 22-3). The aforementioned “clothesline” injury from blunt trauma may cause cricotracheal separation. Even with impending asphyxiation there should only be one attempt at standard rapid sequence endotracheal intubation.^9,10 If this is unsuccessful, a rapid standard tracheostomy is performed between the second and third tracheal rings below the area of injury. Should there be bruising and palpable crepitus over the thyroid cartilage suggestive of an injury to the larynx itself, once again there should only be one attempt at standard endotracheal intubation. Failure to complete this is followed by a rapid standard tracheostomy much as with cricotracheal separation.

FIGURE 22-3 Endotracheal intubation into the distal trachea in a patient with a slash wound to Zone II.

Loss of the airway in Zone II may occur secondary to tracheal deviation or compression from a hematoma resulting from injury to the carotid artery or internal jugular vein, also (Fig. 22-4). With impending asphyxiation, the patient is rapidly moved to the operating room for an attempt at endotracheal intubation over a fiber-optic bronchoscope. If this fails or if the patient is unable to move air when first seen, a cricothyroidotomy is performed rapidly as its high limited central incision (as compared to a standard tracheostomy) avoids the lateral hematoma from the vascular injury.

FIGURE 22-4 Significant Zone II hematoma secondary to gunshot wound of carotid artery. (From Brown MF, Graham JM, Feliciano DV, et al. Carotid artery injuries. Am J Surg. 1982;144: 748–753. Used with permission, © Elsevier.)

With external hemorrhage from a penetrating wound in Zone II, direct compression with a finger or fist on the entrance site is performed in the emergency center and en route to the operating room. The decision on where to make the incision can be made in the operating room after endotracheal intubation has been performed. On rare occasions, there may be internal hemorrhage into the airway when there are adjacent injuries to the carotid artery and trachea. While compression is placed on the carotid artery at the entrance site or at the base of the neck, a cricothyroidotomy is performed. As aspiration is likely to have occurred, fiber-optic bronchoscopy is performed once the injury to the carotid artery has been repaired.

There are two options when exsanguinating hemorrhage occurs from a penetrating wound to the internal carotid artery at the base of the skull in Zone III.¹¹ Finger compression is often only partially successful in this location as the internal carotid artery is deep to the mandible. The quickest option is to maintain manual compression as the patient is moved rapidly to the operating room. Once the patient is intubated and the neck is draped, a #3 or #4 Fogarty balloon catheter is inserted into the wound, advanced 2 cm, and the balloon is inflated^12,13 (Fig. 22-5). If hemorrhage continues, the balloon is deflated and advanced 1 cm at a time and inflated till balloon tamponade controls the hemorrhage. The catheter is then sutured to the skin and the balloon left inflated for 24 hours. When external passage of the balloon catheter is partially successful or unsuccessful, a Foley balloon catheter is passed as it has a larger balloon. If this is unsuccessful, as well, the catheter is removed and manual compression is applied once again. A standard oblique cervical incision on the anterior border of the sternocleidomastoid muscle is made, the internal carotid artery is exposed, and a small arteriotomy is made in the middle of a 6-0 polypropylene purse-string suture. Once again, a #3 or #4 Fogarty balloon catheter is passed through the arteriotomy and inflated sequentially until balloon tamponade is successful. On rare occasions, it may be necessary to pass balloon catheters through the entrance site and through the internal carotid artery simultaneously. A baseline EEG is performed at this time. This is followed by a contralateral carotid arteriogram to evaluate the extent of crossover flow to the side of the brain that has been rendered possibly ischemic by balloon occlusion of the internal carotid artery. Even in the patient with adequate crossover flow, every attempt should be made to keep the patient normotensive with a 100% oxygen saturation level. An intracranial pressure monitor is appropriate, as well, so that treatment can be initiated when ischemic edema occurs. When the baseline EEG is abnormal and the contralateral carotid arteriogram documents inadequate crossover flow, cerebral ischemia is occurring. This is expected in patients who have had a period of significant hypotension secondary to exsanguination prior to inflation of the balloon. In the past, it was recommended that a patient with ipsilateral cerebral ischemia undergo a saphenous vein bypass from the cervical internal carotid artery to the petrous portion through a small temporal craniotomy.¹⁴ Currently, deflation of the balloon(s) and rapid insertion of an endovascular stent into the high internal carotid artery would be the procedure of choice.^15,16

FIGURE 22-5 A Fogarty balloon catheter was inserted into a high cervical stab wound to control exsanguinating hemorrhage. Deflation of the balloon and removal of the catheter were performed on the fourth day after insertion. (From Feliciano DV. Management of penetrating injuries to carotid artery. World J Surg. 2001;25:1028–1035. Used with permission.)

EVALUATION OF PATIENTS WITH MODEST OR MODERATE SYMPTOMS OR SIGNS OR ASYMPTOMATIC PATIENTS (FIG. 22-6)

Zone I

Hemodynamically stable patients with penetrating wounds in proximity to the thoracic outlet should undergo surgeon-performed ultrasound and a chest x-ray. The ultrasound will rule out an associated cardiac injury and document the presence of a hemothorax or pneumothorax. The chest x-ray will aid in tracking the course of the missile and in documenting the presence of a hematoma in the superior mediastinum, base of the neck, or supraclavicular area. There have been several retrospective studies that have documented that a normal physical examination and chest x-ray virtually exclude a vascular injury at the thoracic outlet.^17,18 Even so, certain trauma centers will use a screening CT as an added study to determine the track of a penetrating wound in this area.¹⁹ When the track of a missile or knife wound is in proximity to vessels at the thoracic outlet and there is an adjacent hematoma on the chest x-ray, digital subtraction arteriography (DSA) of the carotid, vertebral, and subclavian arteries or a CT arteriogram (CTA) is performed. This will document the presence and location of a vascular injury and allow for the choice of an appropriate operative incision.

FIGURE 22-6 Evaluation of patients with modest or moderate symptoms or signs or an asymptomatic patient.

There are symptoms (hoarseness, dysphagia, odynophagia), signs (palpable crepitus, continuing air leak through the wound), or findings on a cervical or chest x-ray (cervical or mediastinal air) that suggest a possible injury to the trachea or esophagus. The diagnostic workup is described in Section “Zone II.”

Zone II

The approach to possible injuries in this zone has varied considerably over the past 55 years. Based on the report by Fogelman and Stewart²⁰ at Parkland Memorial Hospital in 1956, mandatory exploration for wounds penetrating the platysma muscle was recommended. This recommendation was based on a mortality rate of 6% in patients undergoing early operation versus 35% in those undergoing delayed operation.

It quickly became obvious, however, that cervical explorations in all patients (overtly symptomatic, modestly or moderately symptomatic, asymptomatic) with penetration of the platysma muscle in Zone II resulted in a “negative” exploration rate of approximately 50%.²¹ A more selective approach to operation based on symptoms and signs as described above was then adopted by many centers. One review article in 1991 comparing the two approaches noted that mandatory cervical exploration for platysma penetration had a mortality rate of 5.8% versus 3.7% for a selective approach.²² Of interest, a negative or nontherapeutic cervical operation occurred in 46.2% of patients treated with mandatory exploration. When patients with modest or moderate symptoms or signs or those who are asymptomatic are managed with a selective approach, only 55–65% eventually come to operation. Numerous large studies subsequently verified the safety of a selective approach in the 1980s and 1990s.^23–33

Physical Examination

Physical examination alone is highly accurate in evaluating an asymptomatic patient with a penetrating (through the platysma muscle) stab wound in Zone II. This is true for patients with gunshot wounds in Zone II, as well, as long as the track is tangential or away from the vascular (lateral) or aerodigestive tract (central).^33–35 With platysma penetration, but without further evaluation by CT, CT angiography, duplex ultrasonography, or endoscopy, serial examinations of the patient’s neck every 6–8 hours for 24–36 hours are appropriate.

Computed Tomography

CT has been used as an adjunct to physical examination over the past decade in selected centers.^19,36,37 In asymptomatic patients with a normal physical examination after a penetrating wound in Zone II, it “contributes minimally” to the sensitivity of physical examination.³⁷ When patients have no “hard signs” of vascular injury in Zone II, but are “at risk for injury to vital structures within the neck,” CT can demonstrate a trajectory away from these structures.¹⁹ With such a trajectomy, “invasive studies can often be eliminated from the diagnostic algorithm.”¹⁹ A more recent study using multislice helical computed tomography/angiography (MCTA) documented a “100% sensitivity and 95.5% specificity in detecting all vascular and aerodigestive injuries sustained.”³⁸

Arteriography, Duplex Ultrasonography, Color Flow Doppler, CTA

Patients with “hard” signs of a vascular injury in Zone II present with external bleeding, bleeding into the trachea or esophagus, an expanding or stable large hematoma, and/or an audible bruit/palpable thrill. Patients with bleeding or an expanding or large stable hematoma undergo an emergency cervical exploration. A patient with a likely arteriovenous fistula should have some type of vascular diagnostic study performed. Should a fistula between the internal carotid artery and jugular vein be present, an endovascular stent rather than cervical exploration may be chosen.

In patients with “soft” signs (modest or moderate signs) of a vascular injury in Zone II such as a history of bleeding at the scene, proximity of a stab, missile, or pellet track, or a small nonexpanding hematoma, the role of arterial diagnostic studies remains controversial. As noted above, physical examination alone is highly accurate in ruling out an arterial injury in the asymptomatic patient. Much as in evaluating possible peripheral arterial injuries, however, there is at least a 3–5% chance of a surgically reparable arterial lesion in a patient who presents with a cervical vascular “soft sign.” And it is likely that a combination of “soft signs” (i.e., proximity of wound and small hematoma) will increase the need for surgical intervention. Therefore, some type of diagnostic study is performed in patients with “soft signs” in most centers (Fig. 22-7).

FIGURE 22-7 Pellet wound in an asymptomatic patient caused 30% transection of left common carotid artery in Zone II. Arteriogram performed secondary to traverse of missile through Zone II.

Four-vessel cerebral arteriography was the longtime standard of care for evaluating the carotid and vertebral arteries. The technique is highly accurate in diagnosing arterial injuries, eliminating nontherapeutic explorations, and allowing for transcatheter embolization when indicated.^39,40 The disadvantages include the time required to allow the interventional radiology team to return to the hospital at night, the dye load required, and the low yield when all asymptomatic or modestly symptomatic patients are studied.⁴¹

Duplex ultrasonography, a combination of real-time brightness (B)–mode imaging and pulsed Doppler velocimetry, has been used in the diagnosis of atherosclerotic occlusive decrease of the carotid artery for 35 years.^41–43 Basically, the technology produces images that define anatomy and a spectral profile that documents flow through the vessel. Numerous reports during the 1990s documented the ease and accuracy of the technique when applied to patients with penetrating wounds in Zone II.^44–47 It was suggested that duplex replace conventional arteriography because of ease of performance and the significant cost-savings that would result.^46–48 This did not happen over time in most trauma centers as the technique can be performed only by a registered vascular technologist or experienced vascular surgeon trained in duplex.

A related technique of “color flow Doppler” has been used to evaluate the carotid arteries after penetrating trauma to Zone II, as well.^49,50 In this technique, flow to and from the point of the Doppler examination is represented on a color scale. Several studies in the 1990s documented that the combination of a careful physical examination and color flow Doppler was a safe alternative to routine contrast angiography.^49,50

For the past 15 years there have been ongoing studies to determine the accuracy of CTA, particularly in patients with possible blunt cerebrovascular injuries (BCVI; to be discussed). Penetrating cervical injuries have been studied, as well, with early reports coming from the Hospital Universitario San Vicente de Paul in Medellin, Colombia.^51,52 Based on the ease and speed of obtaining accurate images reconstructed at 1-mm intervals, the authors from this well-known trauma center concluded that “helical CT can replace conventional angiography in this setting” (penetrating injuries to the neck).⁵² Another early report from 2005, before the current generation of 32- and 64-slice detectors, documented that the use of CTA significantly decreased the number of conventional arteriograms required and negative cervical explorations performed.⁵³ The enthusiasm for using CTA is tempered, of course, by continuing concerns about its accuracy in evaluating possible BCVI.⁵⁴ But the aforementioned 2006 study with a 100% sensitivity in evaluating patients with penetrating cervical wounds is certainly reassuring.³⁸ Based on available data, it appears that multidetector helical CTA is slowly replacing conventional arteriography as a rapid screening modality to evaluate possible arterial injuries in Zone II after penetrating trauma. An equivocal screening study or one in which the anatomic area of interest is obscured by artifacts created by adjacent metallic fragments should be followed by a conventional arteriogram.

Esophagogram/Esophagoscopy/CT

Patients with modest or moderate symptoms of an esophageal injury present with complaints of deep cervical pain, dysphagia, odynophagia, or hematemesis. On examination, palpable crepitus and deep cervical tenderness may be present. An x-ray of the neck will usually demonstrate retropharyngeal or retroesophageal air in the soft tissues, while a pneumomediastinum will be present on a chest x-ray if there has been a delay in the patient’s arrival in the trauma center.

Historically, the time-honored “sip test” was performed in such patients in centers with limited resources.³⁰ A patient who was able to swallow a mouthful of water without severe discomfort was felt to have only a small injury or no injury of the cervical esophagus and was admitted for observation only. The patient who had severe pain with swallowing would then undergo standard diagnostic testing to evaluate for the presence of an esophageal injury.

While CT has now been widely applied in the diagnostic evaluation of patients with penetrating and blunt cervical trauma as previously noted, its accuracy in detecting an injury of the cervical esophagus is unclear. This is because several of the reports in which CT has been evaluated do not include any patients with esophageal injuries.^36,38 For this reason, asymptomatic patients with air in the soft tissues of the neck after trauma, those with a positive “sip” test, or those with a combination of modest/moderate symptoms and signs of an esophageal injury undergo the standard diagnostic evaluation using a contrast esophagogram and endoscopy.^55–57

While there is a risk of secondary necrotizing pneumonitis and pulmonary edema if the contrast agent Gastrografin (meglumine sodium) is aspirated, it remains the initial contrast agent of choice for esophagograms in most centers.⁵⁶ The accuracy of detecting an injury to the cervical esophagus with this agent is 57–80%.^57–60 A “thin” barium study follows a negative Gastrografin swallow or has been used as the primary contrast agent in some centers.^56,57

As contrast esophagograms with either Gastrografin or thin barium have a less than 100% sensitivity in diagnosis, flexible esophagoscopy is next performed in the at-risk patient with a negative contrast study. It has long been known that the combination of a contrast study and esophagoscopy has an accuracy of nearly 100% in patients with esophageal injuries in Zone II.⁶¹ In two studies describing the results of flexible esophagoscopy specifically over the past 16 years, sensitivity was 98.5–100%, specificity 96–100%, and accuracy 97–99.3%.^62,63

Laryngoscopy/Fiber-Optic Bronchoscopy/CT

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