Thoracic Vascular Trauma

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Thoracic Vascular Trauma

• Gan Dunnington MD
• Stanford University
• 10/17/05

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Thoracic Vascular Trauma

• Thoracic Injuries account for 25 of death due to
  trauma
• Majority of penetrating chest trauma managed by
  tube thoracostomy
• Thoracic vascular injuries have high mortality in
  pre-hospital setting
• Trauma center data (Mattox et al. 1989)
• Of 5760 civilian vascular injuries over 30 yrs
• 168 subclavian art, 190 carotid, 39 innominate,
  144 thoracic aorta
• 90 due to penetrating trauma

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Prehospital

• gt80 blunt aortic injury die at scene
• Prevention seatbelts, airbags, driving habits
• EMS
• IVF, intubation, defibrillation, cardiac drugs,
  EKG effective for cardiac arrest
• Immediate transport necessary
• Assessment of mechanism of injury

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Assessment

• History
• Steering wheel impact
• Automobile deformation
• Fall from significant height
• Aircraft accident
• Death of another passenger in same vehicle
• Ejection

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Assessment

• Physical
• Intrascapular murmur
• Pulse/pressure defecit
• T-spine fracture
• Sternum/clavicle/scapula fracture
• Hematoma of thoracic outlet

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Assessment

• Imaging
• CXR
• Hemothorax, tracheal displacement, fractures of
  sternum/clavicle/scapula, loss of aortic knob,
  mediastinal widening, thoracic outlet hematoma,
  deviation of left mainstem bronchus or NG tube,
  foreign bodies, out of focus foreign body

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Assessment

• Imaging
• CT scan (CT Angio)
• Probably imaging modality of choice
• Transesophageal Echocardiography
• Descending aorta
• Difficult to image arch
• Operator dependent

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Assessment

• Imaging
• Arteriography
• gold standard?
• Beware anatomic variants
• Ductus bump
• Ulcerative plaque
• Multiple views required
• MRI/MRA
• Not practical in acute trauma patient

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Preop

• Type and Cross in trauma bay
• Cell-saver
• IV access contralateral to injury, above and
  below diaphragm
• Avoid Right IJ in descending aorta injury?
• Double lumen endotracheal tube
• Permissive hypotension before vascular control
  achieved

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Operative Therapy

• Incisions
• ER thoracotomy
• Left anterolateral ?clamshell
• Sternotomy
• Ascending aorta, arch, innominate, right
  subclavian, left common carotid
• May be extended into left/right neck
• High 3rd interspace anterior thoracotomy
• Left subclavian proximal control
• Supraclavicular incision
• Posterolateral thoracotomy
• Descending aorta

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Operative Therapy

• Communication with anesthesia and perfusionists
  is essential
• Graft selection
• Knitted vs woven, Dacron vs. PTFE
• Shunting
• Clamp-and-sew vs. mechanical perfusion
• Paraplegia with clamp-and-sew approx 15
• Cardiopulmonary bypass requires full
  anticoagulation
• Atrial-femoral bypass with centrifugal pump
• Decreases paraplegia rate to 3

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Thoracic Aorta

• Penetrating trauma
• 50 mortality
• Ascending stab wounds
• Descending gunshot wounds
• Blunt trauma
• Ascending aorta trauma 85 mortality
• Cardiopulmonary bypass, cardioplegia

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Thoracic Aorta

• Arch
• Usually involve takeoff of innominate artery
• Can be managed with Ao-innominate graft, oversew
  arch using side-biting clamps
• Mortality 26

Shin et al. J trauma 2000
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Descending Thoracic Aorta

• Proximal control between carotid and subclavian
• Know patients arch anatomy
• Do not debride aorta
• Do not sacrifice intercostals
• Move clamps closer to injury when identified
• Use fine suture and a soft graft
• 85 repairs require interposition graft
• If less than 50 circumference, may fix primarily
• Mortality of managing blunt descending trauma
  approximately 30

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Descending Thoracic Aorta

• Mattox and Wall classification
• Category 1
• Massive injuries, exsanguination at scene,
  surgical repair futile
• Category 2
• Present to ER with unstable hemodynamics and
  transient response may be time for imaging
• Category 3
• HD stable, contained hematoma, injury found with
  screening, may be transferred to aortic centers

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Descending Thoracic Aorta

• If delay
• Afterload reduction, dP/dT reduction
• Betablockers, SNP
• Keep MAP below preinjury level
• Mediastinal hematoma must be stable on serial
  imaging
• Patient informed of risks
• Supervised by a surgeon
• Optimal to perform surgery within 72 hrs of injury

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Brachiocephalic Vessels

• Incision dictated by injury
• Sternotomy, clamshell, left thoracotomy,
  supraclavicular
• Left subclavian can be ligated
• Follow with carotid-subclavian bypass if needed
• Subclavian vessels well collateralized and
  usually require graft due to soft vessel

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Pulmonary vessels

• Uncommon injury
• Proximal injuries usually found when exploring
  hemopericardium
• May be fixed primarily or require CPB
• Distal injuries may require lobectomy/pneumonectom
  y
• Penetrating lung injury
• Tractotomy and ligation of bleeders air leaks

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Vena Cavae

• Intrathoracic Cavae rarely injured short
• Pericardial tamponade usually found
• Lateral venorrhaphy
• Short inflow occlusion may be used
• Interposition grafts for extensive injury
• CPB can be necessary at times
• Azygous injury mortality similar to caval injury
• May be ligated/oversewn

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Miscellaneous vessels

• Intercostal injury
• May loop rib with heavy absorbable suture
• Mammary artery injury
• Clamshell thoracotomy

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Post-op care

• Most require ICU care
• Rewarming, correction of coagulopathy
• Minimize crystalloid infusions if possible to
  limit pulmonary edema
• Thoracic epidurals for pain management

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Endovascular care

• Numerous series retrospective with trends
  towards efficacy
• Rousseau et al. JTCVS. 2005. France
• 76 pts admitted 1981-2003 with traumatic aortic
  injury
• 35 treated surgically, 7 delayed (avg. 66 days)
• Mortality/paraplegia 21/7
• No death or paraplegia in delay group
• 29 stent grafted at isthmus
• No major morbidity, no mortality in stent graft
  group at 46 months follow up

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Endovascular care

• Under investigation
• Allows avoidance of morbid thoracic incisions
• May allow delayed repair
• May cover left subclavian artery with stent-graft
• Results are equal to open surgery in short-term
  follow up

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Summary

• Injuries to thoracic aorta often fatal at scene
• Hemodynamically unstable patients require
  emergent thoracotomy
• Careful consideration needs to be given to
  incision
• Adjuncts of shunts, grafts, CPB often necessary
  for surgical repair
• Emerging role for endovascular therapy

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Reference

• Wall M, Huh J, Mattox K. Thoracic Vascular
  Trauma. Vascular Surgery 2005 71 .