Thoracic Vascular Trauma Gan Dunnington MD Stanford University 10/17/05.

Thoracic Vascular Trauma

Gan Dunnington MD

Stanford University

10/17/05

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

Prehospital

• >80% 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

Assessment

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

Assessment

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

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

Assessment

• Imaging– CT scan (CT Angio)

• Probably imaging modality of choice

– Transesophageal Echocardiography

• Descending aorta

• Difficult to image arch

• Operator dependent

Assessment

• Imaging– Arteriography

• “gold standard?”• Beware anatomic

variants– Ductus bump– Ulcerative plaque

• Multiple views required

– MRI/MRA • Not practical in acute

trauma patient

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

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

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%

Thoracic Aorta

• Penetrating trauma – 50% mortality– Ascending –stab wounds– Descending – gunshot wounds

• Blunt trauma– Ascending aorta trauma – 85% mortality

• Cardiopulmonary bypass, cardioplegia

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

Descending Thoracic Aorta

• Proximal control between carotid and subclavian• Know patient’s 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%

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

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

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

Pulmonary vessels

• Uncommon injury• Proximal injuries usually found when

exploring hemopericardium– May be fixed primarily or require CPB

• Distal injuries may require lobectomy/pneumonectomy

• Penetrating lung injury – – Tractotomy and ligation of bleeders air leaks

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

Miscellaneous vessels

• Intercostal injury– May loop rib with heavy absorbable suture

• Mammary artery injury– Clamshell thoracotomy

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

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

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

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

Reference

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