1. Cardiac Trauma Peter I. Tsai, MD, FACS Professor of Surgery
Chief, Division of Cardiothoracic Surgery
University of Hawaii, Manoa
Medical Director, Queen’s Heart
Honolulu

2. Learning Objectives
Identify regions of the heart most likely injured from trauma
Identify aortic injury and treatment
Identify valvular injury and treatment
Identify coronary injury and treatment

3. Cardiac Trauma Background
The heart is encased in the chest cavity:
Manubrium
Sternum
Rib cage
Injury can come from penetrating vs non- penetrating forces

4. Background Penetrating trauma Non-penetrating trauma
Right ventricle is most commonly injured
VSD is the most common intracardiac injury
Non-penetrating trauma
Blunt cardiac injury (myocardial contusion)
Coronary artery injury
Atrial/ventricular rupture

5. Blunt Cardiac Injury Historical perspective
1st recorded cardiac chamber rupture reported by Borch (1679) and Akenside (1764)
Fischer (1868) described 7 myocardial contusions and 69 traumatic ruptures

6. Blunt Cardiac Injury
Beck and Bright (autopsies and animal experiments)
Demonstrated sequentially more severe forces are responsible for an entire range of cardiac trauma
Enormous force required to rupture the heart

7. Blunt Cardiac Injury
Parmley (1958) reviewing autopsy cases in Armed Forces Institute of Pathology
Blunt cardiac injury had 0.1% incidence
Majority isolated to chamber ruptures
Right then left ventricle
Right then left atrium
Blunt cardiac injury (myocardial contusion) being most common

8. Blunt Cardiac Injury Mechanism, pathophysiology and incidence
Kinetic energy (blast effect), direct crushing, traction/torsion from deceleration forces, or sudden rise in blood pressure
Commotio cordis
True incidence difficult to measure—majority go on to recover

9. Blunt Cardiac Injury Clinical presentation:
Acute tampanade usually fatal
Myocardial contusion induces arrythmia and failure that improve with time
Coronary artery injury leads to MI
Valvular tears, symptomatic aortic/mitral insufficiency (immediate), tricuspid insufficiency (late)

10. Blunt Cardiac Injury Diagnosis H&P EKG
Cardiac enzymes/troponins (cTnI)
TTE/TEE
Radionucleide scans

11. Blunt Cardiac Injury Assessment and Management
Pericardial injury (resulting in cardiac herniation)
Valvular, papillary muscle/chordae tendinae and septal injury
Chamber rupture
Coronary artery injury--MI

13. Cardiac Herniation

14. Cardiac Herniation

15. Blunt Cardiac Injury Assessment and Management Myocardial contusion
Should be eliminated (Mattox)
Blunt cardiac injury with
Cardiac failure
Complex arrythmia
Enzyme abnormality

16. Blunt Cardiac Injury Conclusion:
Blunt cardiac injury should always be suspected from a good H&P, prompting further diagnostic testing with EKG monitoring, serial enzyme measurements if clinically indicated. Sonographic exam can elucidate presence of pericardial fluid or cardiac or valvular dysfunction that may require prompt surgical intervention

17. Penetrating Cardiac Injury
Historical Perspective
Always met with death as described in death of Sarpedon from an impalement of a lance to the heart in Iliad
Hippocrates, Aristotle, Galen, Fabricius and Boerhaave, all described such wounds as futile

18. Penetrating Cardiac Injury
Historical Perspective
Morgagni (1761) described compressive effects of blood on the heart
Larrey pioneered technique of pericardial window
Duval described first sternotomy
Spangaro (1906) described first left anterolateral thoracotomy

19. Penetrating Cardiac Injury
Historical Perspective
Beck (1926) described Triad physiology of cardiac tamponade, and repair technique of placing mattress sutures under the coronary to spare ligation

20. Penetrating Cardiac Injury
Historical Perspective
Harken (1946) described removal of foreign bodies adjacent to the heart and great vessels
Beal described 1st emergency department thoracotomy
Cooley described potential benefits of CPB in management of selected cardiac injuries

21. Penetrating Cardiac Injury
Historical Perspective
Mattox further refined and protocolized emergency department thoracotomy and cardiorrhaphy including emergency CPB

22. Penetrating Cardiac Injury
Incidence
Uncommon and seen in busy urban trauma centers
Feliciano described 48 cardiac injuries in one year at Ben Taub
Mattox (1989) described 30 yr experience of 539 cardiac injuries

23. Penetrating Cardiac Injury
Etiology
Gun Shot Wounds (63%)
Stab Wounds (36%)
Shotgun and impalement injuries (1%)

24. Penetrating Cardiac Injury
Clinical Presentation
Related to the trajectory of stab wounds, but not so with gun shot wounds (“magic bullet”)
Frank exsanguination
Tampanade (Beck’s triad present in 10%)
Moreno described 77% survival (vs 11%) in patients presenting with tampanade; R chamber injuries confer 79% survival (vs 28% for L chamber injuries)

25. Penetrating Cardiac Injury
Diagnosis
H&P
Echocardiography (96% accuracy, 97% specificity)
Subxyphoid pericardial window

26. Penetrating Cardiac Injury
Techniques for cardiac injury repair
Incisions
Median sternotomy
Anterolateral thoracotomy
Adjunct maneuvers
Exposure of posterior injury
Pledgeted sutures on apex, satinsky clamp on right ventricular angle, sequential placement of folded wet towel, stabilizing devices

28. Great Vessel Injury Approach: Median sternotomy
Innominate artery is most commonly injured: bypass exclusion technique
Posterolateral thoracotomy
Left subclavian artery
Either technique
Left common carotid artery

29. Exposure of Thoracic Vessels

30. What are you going to do?

32. Cardiac Trauma 10% of penetrating chest trauma involves the heart
Right ventricle is the most commonly injured in stab wounds, followed by LV, then RA, LA
Suspect in any injury near the heart (precordium-epigastrium-superior mediastinum)

33. Cardiac Trauma
Patient may present with hypotension, and shock, hemothorax or in tamponade
Beck’s Triad (10%): distended neck veins- muffled heart sounds – hypotension
Shock with elevated CVP

35. Penetrating Cardiac Injury
Techniques for cardiac injury repair
Repair of atrial injuries with 4-0 non-pledgeted polypropylene sutures
Repair of ventricular injuries with 2-0, 3-0, or 4-0 pledgeted sutures in horizontal mattress fashion; fibrin sealant to reinforce if needed

36. Coronary Artery Injuries
LAD is the most commonly injured in blunt and penetrating
Followed by RCA
Then Left circumflex

37. Penetrating Cardiac Injury
Techniques for cardiac injury repair
Coronary artery injury
Proximal require bypass or “stent”
Distal third may be ligated
Pericoronary injuries require horizontal mattress sutures underneath the vessel for safe repair

38. What are you going to do?

40. Specific Cardiac Injuries
Ventricular Aneurysm
Very rare
If the coronaries are normal then the injury is in the myocardium and not secondary to coronary injury—may be a pseudo aneurysm

41. Specific Cardiac Injuries
Traumatic Septal Defects
Located in muscular septum near apex
New systolic murmur+ acute heart failure
Dx : Echo (TTE vs TEE)
Oxygen saturation step up of more than 20 mmHg between right atrium and R ventricle is diagnostic of left to right shunt

42. Traumatic Septal Defects
Repaired all the time, unless the shunt is small
(with P/S shunt less than 1.5 to 1)
IABP helps to decrease the shunt

43. Aortic Valve Injury The most common injured valve
Mechanisms: avulsion of commisures – extension of blunt traumatic aortic rupture at aortic root when falling from a height vs penetrating
Aortic regurgitation
Resuspension of the valve in commisure disruption by pledgeted sutures

44. Aortic Valve Injury
Leaflets injury usually needs replacement and can not be repaired
In case of dissection with valve injury a composite graft may be needed with coronary implantation

45. Mitral Valve Injury Rare Chordal or papillary muscle rupture TTE , TEE
IABP
Replacement is usually the rule

46. Tricuspid Valve Injury
More common than mitral because it is more anterior in location
Right bundle branch block, cardiomegaly without signs of left ventricular failure
Presentation is usually delayed with progressive “RHF” symptoms

47. Tricuspid Valve Injury
Treatment: many do not require treatment
But in young active patients
Replacement rather than repair may have to be done

48. Ideally

53. Deeper Injuries Valvular Septal Aortic Arch Vessels
Proximal Coronaries

54. Penetrating Cardiac Injury
Results
Stab wounds 80% survival
Gun shot wounds 40% survival

55. Penetrating Cardiac Injury
Conclusion
Penetrating cardiac injury should prompt a comprehensive workup, with sonographic exam being very useful to diagnose presence of pericardial fluid. Workup can be more extensive in a hemodynamically stable patient with CT studies. Anterolateral thoracotomy can be used in the emergent setting to cross clamp the descending aorta and perform necessary cardiac repairs. Median sternotomy can be used in a more stable patient with identified cardiac injuries repaired

56. Aortic transection

57. Acute Traumatic Aortic Transection
Mechanisms and Types of Injury
Penetrating trauma
Exsanguination, pseudoaneurysm, partial transection with resultant intimal flap, intimal dissection, thrombosis and propagation

58. Acute Traumatic Aortic Transection
Mechanisms and Types of Injury
Blunt trauma
Traction and deceleration forces
Vertical deceleration injures ascending aorta and innominate artery
Horizontal deceleration strains aortic isthmus
Osseous pinch between sternum and spinal column injures the great vessels

59. Acute Traumatic Aortic Transection
Natural History
Free rupture of the thoracic aorta leads to immediate death in 75-90% of cases
Few that survive with containment of pseudoaneurysm
8-13% rupture in 1st hour
30% rupture within 24 hours
50% rupture within 1 week

60. Acute Traumatic Aortic Transection
Diagnosis
Detailed H&P
Aortic isthmus injury can produce decreased blood pressure in left arm
CXR, Echocardiography
CT screening modality
Aortography

61. Acute Traumatic Aortic Transection
Assessment and Management
CXR normal, low probability
CT to screen if mechanism highly suspicious
Angiography if CXR widened mediastinum or screening CT suggestive
Short acting beta blockers to reduce blood pressure

65. Acute Traumatic Aortic Transection
Ascending aortic/Arch injuries
CPB with simple repair or graft interposition with ascending aortic injury
May require circulatory arrest with isolated right subclavian artery (for antegrade cerebral perfusion) cannulation with femoral/atrial venous cannulation with interposition graft repair

66. Acute Traumatic Aortic Transection
Descending Thoracic Aortic Injuries
Left thoracotomy incision
Identification of left subclavin artery, left common carotid artery, recurrent laryngeal nerve
Left heart bypass vs clamp and sew

67. Acute Traumatic Aortic Transection
Descending Thoracic Aortic Injuries
Clamp and sew
Earliest reported paraplegia at 24 min
Paraplegia 18% at 34 min
Paraplegia 80% at 60 min
Paraplegia 100% at 120 min

68. Acute Traumatic Aortic Transection
Descending Thoracic Aortic Injuries
Left heart bypass
Paraplegia 18% at 120 min
Anterior spinal artery from confluence of both vertebral arteries at the basilar artery
Artery of Adamkiewicz (arteria radicularis magna) arises from T5-T8 15%, T9-T12 75%, L1-L2 8%, L3 1.4% and L4-L5 0.2%

69. Acute Traumatic Aortic Transection
Descending Thoracic Aortic Injuries
Methods to minimize spinal cord injury
Whole body hypothermia (full function at 60 min if temp cooled to 30 deg C)
Perfusion of distal aorta
Reattachment of intercostal and lumbar arteries
Drainage of CSF
Localized cooling of spinal cord
Monitoring of motor evoked potentials

70. Descending Thoracic Aortic Injuries
Endovascular treatment
Lower postoperative mortality vs open OR 0.44
Spinal cord complication vs open OR 0.32
Gore Excluder, Medtronic Talent, Cook Zenith are all FDA approved for aneurysms, off-counter use for transections

75. Thoracic Aortic Injuries
Conclusion
Blunt or penetrating injuries to the chest may include thoracic aorta. Successful repair is determined by complete proximal and distal control of the injury with or without cardiopulmonary bypass. Interposition graft is usally employed with the repair, although primary repair is equally optimal if the tissue reapproximates well. Aortic endograft stent repair has evolved through the last decade as the gold standard.

77. Thank you