------------------------------------------------------------------------------ TITLE: PENETRATING NECK TRAUMA SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: September 23, 1992 RESIDENT PHYSICIAN: Eric W. Bridges, M.D. FACULTY: Francis B. Quinn, Jr., M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. ------------------------------------------------------------------------------ "This material was prepared by resident physicians in partial fulfillment of educational requirements established for 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 should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." I. HISTORICAL PERSPECTIVE A. Prior to WWII 1) Ligation of major vessels described as early as 1522 by Ambrose Pare 2) Ligation was prodecure of choice for vascular injury through WWI, associated mortality rates of 11% to 60% 3) Significant neurologic impairment in 30% patients B. Since WWII 1) mandatory exploration of all penetrating neck wounds, through the platysma 2) Fogelman and Stewart reported Parkland Memorial Hospital experience of early, mandatory exploration with mortality of 6% vs. 35% for delayed exploration 3) 40% to 60% rate of negative explorations with mandatory exploration 4) Present mortality for civilian wounds is 4% to 6% II. ANATOMY A. Zone I 1) bound superiorly by the cricoid and inferiorly by the sternum and clavicles 2) contains the subclavian arteries and veins, the dome of the pleura, esophagus, great vessels of the neck, recurrent nerve, trachea 3) signs of significant injury may be hidden from inspection in the mediastinum or chest B. Zone II 1) bound inferiorly by the cricoid and superiorly by the angle of the mandible 2) contains the larynx, pharynx, base of tongue, carotid artery and jugular vein, phrenic, vagus, and hypoglossal nerves 3) injuries here are seldom occult 4) common site of carotid injury C. Zone III 1) lies above the angle of the mandible 2) contains the internal and external carotid arteries, the vertebral artery, and several cranial nerves 3) vascular and cranial nerve injuries common D. Fascial layers 1) Superficial cervical fascia - platysma 2) Deep cervical fascia a. Investing - sternocleidomastoid muscle, trapezius muscle b. Pretracheal - larynx, trachea, thyroid gland, pericardium c. Prevertebral - prevertebral muscles, phrenic nerve, brachial plexus, axillary sheath d. Carotid sheath - carotid artery, internal jugular vein, vagus nerve III. MECHANISM OF INJURY 1) over 95% of penetrating neck wounds are from guns and knives, remainder from motor vehicle, household, and industrial accidents 2) the amount of energy transferred to tissue is difference between the kinetic energy of the projectile when it enters the tissue, and the kinetic energy of any exiting fragments or projectiles 3) the velocity of the projectile is the most significant aspect of energy transfer (K.E. = 1/2 mv^2) 4) muzzle velocity less than approximately 2000 ft/s is considered low velocity 5) .22 and .38 caliber handguns have a velocity of 800 ft/sec 6) .357 magnum and .45 as high as 1500 ft/sec 7) high power rifles: 2200-3000 ft/sec 8) shotguns at less than 20 feet--1200-1500 ft/sec 9) injuries inflicted with high power rifles, shotguns at less than 20 feet, and .357 and .45 caliber handguns can cause extensive damage extending beyond the path of the projectile and should be explored 10) stab wounds do not have this effect 11) beware of the stab wound just over the clavicle--the subclavian vein is at high risk IV. INITIAL STABILIZATION AND EVALUATION A. Establish Airway 1) be prepared to obtain an airway emergently 2) intubation or cricothyrotomy 3) beware of cutting the neck in the region of a hematoma-- disruption thereof may lead to massive bleeding 4) must assume cervical spine injury until proven otherwise B. Breathing 1) Zone I injuries with concomitant thoracic injuries (pneumothorax, hemopneumothorax, tension pneumothorax) may compromise ventilatory mechanics C. Circulation 1. Hemostasis 1) bleeding should be controlled by pressure 2) do not clamp blindly or probe the wound depths 3) the abscence of active visible hemorrhage does not rule out serious vascular injury, especially in zone I where the mediastinum and chest may hide it 2. Volume Resuscitation 1) start two large bore IVs 2) at least one should be in the lower extremity--be careful of an IV in the arm on the same side as a possible subclavian injury D. History 1) Obtain from EMS personnel, witnesses, patient 2) Mechanism of injury - stab wound, gunshot wound, high-energy, low-energy, possible trajectory of stab 3) Estimate of blood loss at scene 4) Any associated thoracic, abdominal, extremity injuries 5) Neurologic history E. Physical Examination 1) thorough head and neck exam using palpation and the stethescope to search for thrills and bruits 2) neurologic exam to include mental status, cranial nerves, and spinal column 3) examine the chest, abdomen, and extremities 4) be sure to examine the back of the patient as unsuspected stab or gunshot wounds have been missed here 5) Don't blindly explore wound or clamp vessels F. Radiographs 1) CXR - inspiratory/expiratory films to assess for phrenic nerve injury, look for pneumothorax 2) cervical spine film to rule out fractures 3) soft tissue neck films both anterior and lateral 4) arteriograms, constrast studies as indicated G. Preoperative preparation 1) surgeon and staff ready for emergent/urgent tracheotomy 2) gentle cleansing of wound, betadine paint only 3) prepare vein donor site for possible vascular, prepare chest for possible thoracotomy 4) avoid nasogastric tube until airway secure, patient anesthetized V. TYPES OF INJURY AND ASSOCIATED FINDINGS A. Findings suggestive of airway injury 1) hemoptysis 2) hoarseness 3) soft tissue crepitus 4) sucking type wounds B. Pharyngeal-esophageal injury 1) dysphagia 2) soft tissue crepitus 3) enlarged retropharyngeal space 4) tachycardia and fever C. Vascular injury 1) expanding hematoma 2) CNS deficit 3) pulse deficit 4) thrills and bruits 5) hypovolemic shock 6) persistent hemorrhage D. Neurologic injury 1) hoarseness 2) cranial nerve deficits 3) coma 4) hemiplegia VII. EXPLORATION VERSUS OBSERVATION 1) many experts have adopted a policy of selective exploration 2) decreased number of negative explorations, increased number of positive explorations 3) decreased cost of medical care, maybe 4) no increase in morbidity and mortality especially when adjunctive diagnostic studies are used when indicated 5) observed patients can be taken to the operating room if clinical conditions change, only 2% of patients initially observed in most studies A. The clinical evaluation 1) any unstable patient or patient with clinical evidence of significant injury must be explored 2) studies have shown that the clinical evaluation is of highly reliable at detecting significant injury, positive predicative value of 47%, negative predicative of 86% 3) patients selected for observation will have 5% or less incidence of subsequent exploration for repair of unsuspected injury 4) remember that esophageal injury rarely manifests early--grave consequences may arise when there is delay in diagnosis B. Site of injury 1) zone I a) adequate exposure for exploration and repair may require sternotomy, clavicle resection, or thoracotomy b) because of the high attendant morbidity of exploration, suspicion of injury must be great or demonstrated by adjunctive diagnostic studies before taking the patient to the operating room c) cardiothoracic surgery consultation a must 2) zone II a) few injuries will escape clinical examination b) most carotid injuries occur here c) adjunctive studies, except barium swallow and esophagoscopy where indicated, are not necessary d) clinically negative zone II injuries can generally be safely managed by observation 3) zone III a) high rate of vascular injury, often multiple b) often difficult if not impossible to obtain proximal and distal control of bleeding vessels c) exploration has high attendant rate of injury to cranial nerves d) adequate exposure may require mandibular subluxation or mandibulotomy e) angiography indicated to delineate site and accessibility of injury f) embolization techniques of greatest value here C. The clinical setting 1) observation requires admission to an intensive care unit where serial examination can be performed by a surgeon 2) adjunctive studies must be available at all times and at a moments notice 3) absence of these dictates exploration of all patients VI. MANAGEMENT OF SPECIFIC ORGAN INJURIES A. Esophageal and pharyngeal injuries 1) invert the mucosal edges and close with absorbable sutures 2) augment exploration with esophagoscopy 3) drain the neck but do not place the drain over the line of closure B. Airway 1) direct laryngoscopy where laryngeal injury is suspected 2) damage is then inspected through a laryngofissure 3) mucosal lacerations are closed with absorbable sutures 4) cover raw surfaces with flaps from surrounding mucosa or with nasal or buccal mucosa 5) a keel or soft stent is placed when denuded areas are apposed 6) tracheotomy one ring below injury when high tracheal injury 7) suprahyoid muscle release for primary closure of segmental defect C. Vascular 1) the subclavian and internal jugular veins can be ligated without adverse effect 2) major arteries should be repaired where possible except the vertebral which can be ligated 3) partial lacerations can be closed primarily--vein patches will help prevent subsequent stenosis 4) high velocity wound produce a surrounding area of contusion which may be thrombogenic and which must be resected; if the resected area allows closure without tension, the ends can be mobilized and closed primarily 5) when tension is required, vein grafts from the saphenous or internal jugular are interposed 6) in central neurologic deficits: a) repair the artery when there are minimal deficits b) when there are gross deficits, restoration of flow can convert ischemic infarcts into hemorrhagic ones--the artery should be ligated c) a deterioration in neurologic status dictates arteriography and reexploration d) EC-IC bypass may be beneficial when there are progressing neurologic deficits with irreparable injury to the internal carotid artery VII. Conclusions 1) Maintain a healthy respect for apparently minor neck wounds because of potential fatal outcome for initially injuries 2) Do not try to infer trajectories of gunshot wounds from clinical or radiographic studies 3) Careful history and complete physical examination with appropriate ancillary studies will avoid missed injuries 4) Arteriography for zone I and zone III injuries, may not be required for low-energy zone II wounds 5) Vascular injuries most immediately life-threatening, missed esophageal injury causes late mortality ----------------------------------------------------------------------------- BIBLIOGRAPHY 1) Sclafani, Salvatore and Alan Goldstein;" The Management of Arterial Injuries Caused by Penetration of Zone III of the Neck"; The Journal of Trauma, vol. 25, no.9 Sept.1985. 2) Ordog, Gary J., Albin, David et al: "110 Bullet Wounds to the Neck"; The Journal of Trauma: vol25,no 3;March 1985. 3) North, Charles M, Ahmadi, Jamshid et al;" Penetrating Vascular Injuries of the Face and Neck; American Journal of Radiology"; vol.147 pp.995-999; November 1986. 4) Panetta, Thomas, Sclafani, Salvatore et al:"Percutaneous Transcatheter Embolization for Arterial Trauma"; Journal of Vascular Trauma;vol 2, no 1,pp.55-62, January 1985. 5) Richardson, David, Flint, Lewis et al;"Penetrating Arterial Trauma"; Archives of Surgery: vol 122 pp. 678-683, June 1987. 6) Ordog, Gary; "Penetrating Neck Trauma"; The Journal of Trauma: vol 27, no 5;pp.543-550, May 1987. 7) Meyer, Joseph P., Barrett, John: "Mandatory vs Selective Exploration for Penetrating Neck Trauma; A Prospective Assessment"; Archives of Surgery: vol 122,pp.592-600,May 1987. 8) Carducci, B., Lowe, RA, Dalsey W.: "Penetrating Neck Trauma: Consensus and Controversies"; Annals of Emergency Medicine; vol 15,no 2;pp. 208-215, Feb. 1986. 9) Jurkivich, Gregorio, Zingarelli, William: "Penetrating Neck Trauma: Diagnostic Studies in the Asymptomatic Patient"; Journal of Trauma; vol.25,no.9,pp. 819-825,May 1985. 10) Glatterer, Milton, Toon, Richard, et al;"Management of Blunt and Penetrating External Esophageal Trauma"; The Journal of Trauma; vol 25, no 2;pp.784-791, July 1985. 11) The Otolaryngology Clinics of North America, Aug. 1983. 12) Merion, RM et al: "Selective Management of Penetrating Neck Trauma: Cost Implications"; Archives of Surgery; vol.116,pp. 691-696, 1981. 13) Thal, ER, Meyer, DM: Penetrating Neck Trauma. 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