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 3 rd 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 France –76 pts admitted 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:.