Post on 22-Jul-2015
transcript
DR PRIYANKA
Complex network of neurovasuclar & muscular structures supported by various fascial planes.
In the neck multiple vital structures are vulnerable to injury in a small anatomic area and not protected by bone.
Neck InjuriesNeck trauma mechanisms:
blunt
penetrating : 5-10% of all trauma cases
The types of injuries:
airway (laryngotracheal),
digestive tract (pharyngoesophageal),
vascular system
neurologic system
PENETRATING INJURIESStab injuries –Knife, razor blades, glass, etc
•Predictable damage pathway
•Stab vs. Projectile Injury
•Higher incidence of subclavian laceration
•Lower incidence of spinal cord injury
•Projectile
•Handgun
•Rifle
•Shotgun
Three basic types: low velocity (handguns), high velocity (rifles) and shotguns.
Handguns ~ 400ft/lb,
Rifles 3000ft/lb,
Shotgun energy and impact varies with distance
Projectile injury mechanics
Kinetic Injury of Missile: more energy = more damage
•Velocity: higher velocity = more KE,
•Yaw –“tumbling”, deflection of the bullet around the axis of the travel.
•More tumble = more transmitted energy, larger damage path
•Strong metal jacket allows through and through injury
HANDGUNS-
Classified by projectile type, speed and calibre.
Tumbling bullet : deflection of the bullet around the axis of the travel, causes more injury in a wider path
Low velocity bullets(lead shielded) leave a radiographic pathway
RIFLE
Hunting rifle- soft tip bullets create larger cavity, no exit wound, fragments causing injury far away from primary path.
Military rifle- bullets create clean hole, through and through wound without lead track to follow
High velocity missiles tears tissues & transmits energy to surrounding tissue.
Cavity upto 30 times size of missile created & pulsate 5-10ms creating
waves of contraction and expansion of tissues.
Hence the finding of punctured viscus without direct penetration- alerts the surgeon to examine trachea and esophagus even when bullet is 2 inches away.
Bullet Tip
•“Expanding bullet” –hollowpoint, softnose
•More energy transmission and more soft tissue injury
•Entry/Exit wound, pathway through tissue
ZONES IN NECK
Roon & Christensen`s Classification
Zone 1: superiorly from the sternal notch & clavicles to the cricoid cartilage (injury affects both neck & mediastinal structures)
Zone 2: cricoid cartilage to the angle of the mandible
Zone 3: angle of the mandible to the
ZONES OF NECK - CONTENTS Zone I: includes the
vertebral and proximal carotid arteries, major thoracic vessels, superior mediastinum, lungs, esophagus, trachea, thoracic duct, spinal cord
Zone II: involve the carotid and vertebral arteries, jugular veins, esophagus, trachea, larynx, and spinal cord
Zone III: includes the distal carotid and vertebral arteries, pharynx, and spinal cord
ZONE I considerations
Dangerous Area, Mortality –12%
•Close proximity of vasculature to thorax
•Osseous Shield : bony thorax and clavicle
•Protects against injury
•Surgical Access difficult
•Surgical Access
•May require sternotomy or thoracotomy
•Mandatory exploration is NOT recommended
ZONE II considerations
Largest and most commonly involved area ~60-75%
•No Osseous Shield
•Surgical Access “Easy”
•Proximal and Distal control of vasculature “easy”
•Fascial layers may tamponade
•Elective vs Mandatory Exploration
ZONE III considerations
Dangerous Area
•Proximity of vasculature to skull base, high carotid injury
Cranial nerve injury at skull base
•Surgical Access difficult
•Surgical Access
•Mandibulotomy
•Craniotomy
•Mandatory exploration is NOT recommended
•Cranial neuropathies may be indicative of injury to nearby vasculature
•Frequent examination oral cavity
FASCIAL PLANES
Platysma: thin muscle covers the entire anterior triangle and the anteroinferior aspect of the posterior triangle; serves as an important planar landmark when evaluating penetrating neck injuries
Deep cervical fascia: invest deep structures; important due to the pretracheal deep fascia’s communication to the anterior mediastinum (neck trauma can lead to mediastinitis)
SIGNS AND SYMPTOMS AIRWAY :
.Respiratory distress
•Stridor
•Hoarseness
•Hemoptysis
•Tracheal Deviation
•Subcutaneous Emphysema
•Sucking Wound
VASCULAR:
•Hematoma
•Persistent Bleeding
•Absent Carotid Pulse
•Bruit
•Thrill
•Hypovolemic Shock
•Change of Sensorium
•Neurologic Deficit
NEUROLOGIC
•Hemiplegia
•Quadriplegia
•Coma
•Cranial Nerve Deficit
•Change of Sensorium
•Hoarseness
•*Signs of stroke/cerebral ischemia
ESOPHAGEAL INJURIES
•Subcutaneous Emphysema
•Dysphagia
•Odynophagia
•Hematemesis
•Hemoptysis
•Tachycardia
•Fever
•Most commonly missed zone II injury
•SignificantDelayedmorbidity and mortality
Hard Signs
Ongoing hemorrhage
Large or expanding hematoma
Bruit
Massive blood loss at scene
Hemiparesis or hemiplegia
Extensive subcutaneous emphysema
Stridor
INITIAL MANAGEMENT ABC’s
Always be ready for Intubation, Cricothyroidotomy, Tracheostomy (multibleintubation attempts might enlarge a pyriformsinus laceration/ tracheal tear may be exaceratedby neck extensions)
Extension of neck should be avoided until a cervical spine injury is ruled out
Direct pressure for bleeding
AP and Lateral neck and chest x-rays( chest tube insertion in pneumothorax)
Look for vascular injury(pulse deficit,activebleeding,hypotension, expanding hematoma) in high volume trauma
Acute spinal injury- hypotension without tachycardia
Look for Cranial Nerve injury, in cases with 12th nerve injury suspect carotid artery injury
Horners Syndrome- injury to sympathetic chain or carotid atery
DIAGNOSTIC EVALUATION
.Angiography
•Carotid Ultrasound
•CT Angiography
•MRI/MRA
•Direct laryngoscopy, rigid bronchoscopy, rigid esophagoscopy
•Flexible endoscopy
•Gastrograffin/Barium swallow
CT ANGIOGRAPHY
Advantages
•Superior image quality
•Readily available, quick
•Limited interuservariability
•Safe
•Shows surrounding structures
Limitations
Poor timing of contrast load
Patient movement
Metallic artifact
• Not therapeutic
Angiography
In zone I and zone III : routinely
When b/l neck involved, 4 vessel angiography : b/lcarotid and vertebral arteries
Zone II injuries : easily accesible, low risk for exploration
Angiography : stable pts with persistent hemorrhage / neurologic deficits
MANAGEMENT
Zone 1 dangerous area- vascular strusture close to neck, osseous shield makes surgical exploration difficult.
Right side approached through median sternotomy, left side by left anterior thoracotomy.
High fatality rate.
Zone 2 –common 60-75%
Mandatory or selective exploration depending on signs, symptoms, haemodynamic stability, diagnostic radiographic , endoscopic techniques, angiography
Zone 3- protected by skeletal structures and difficult to explore. May need to displace or divide mandible.
Injury to cranial nerves exiting skull base indicate injuries To great vessels in their proximity(may necessitate craniotomy for exploration)
MANDATORY VS SELECTIVE MANAGEMENT
Mandatory immediate surgical exploration
Massive bleeding, expanding hematoma, non expanding hematoma with haemodynamicinstability, haemomediastinum, hemothorax, hypovolemic shock
Selective exploration
Hemodynamically stable, non life threatening injuries, Can undergo imaging investigations.
SELECTIVE VS MANADATORY NECK EXPLORATION
Exploration of Neckgeneral principles GA Airway- nasotracheal/orotracheal intubation;
cricothyroidotomy/traecheotomy Position- supine, neck extended, turned to opposite
side(if no C spine injury) Exposure-chest & face for zone 1 & 3 injuries Approach- localised injury :horizontal skin crease
insicion, subplatysmal flaps;wider exploration: lond incision along anterior border
of sternocleidomastoid. Additional exposure:zone 1 divide omohyoid muscle,
for bilateral exploration :apron flap; zone 3 –anterior dislocation of mandible.
Active bleeding should be controlled with digital
pressure until direct vascular control is achieved
Wounds should not be probed, cannulated or locally
explored
these can dislodge clot and lead to uncontrolled
hemorrhage or embolism
• Zone I - SCM incision + sternotomy
• Zone II - SCM incision
• Zone III - post-auricular extension with SCM incision + mandibular subluxation
Operative Approach
• Provides exposure of the carotid sheath, pharynx and cervical esophagus
• Can be lengthened to provide more extensive proximal or distal exposure
• If bilateral exploration is necessary, separate incisions can be done
SCM Incision
• Neck trauma damages cervical vessels in 25% of cases
• Penetrating trauma predominates
− 30% have associated injuries in the neck and thorax
• Blunt trauma accounts for < 10% of injuries
− mortality rate = 10 – 30%
Cervical Vascular Injuries
VASCULAR PENETRATION Zone I : Thoracic surgery
low cervical incision : sufficient exposure
Zone II : Injuries at skull base may require mandibulotomy for exposure
ICA injury : fogarty catheter through PruitT Inahara shunt
All veins can be safely ligated, if both ijv ‘s injured : one side repaired.
Common carotid/ ICA in zone II : exploration is mandatory
If the artery is not pulsating : external carotid branches may be followed retrograde from facial artery at submandibular/ superiro thyroid artery
Vascular injuries : end to end anastomosis
autovenous grafting ligation for irreparable injuries
• Injuries to the ICA are more problematic
• Simple injuries with no interruption of flow should be repaired
• Injuries to CCA or ICA with interrupted flow in the vessel, repair creates a theoretical disadvantage
Management
• Interruption of flow may lead to focal brain ischemia and partial disruption of blood-brain barrier
• Sudden restoration of blood flow may cause hemorrhage in the area of ischemia and worsen the extent of brain injury
• Converted an ischemic infarct into a hemorrhagic infarct
Disadvantage