1. Thoracic Aortic Aneurysms & Aortic Dissection
Dr. Moaath AlSmady.
Division of Cardiothoracic/Vascular surgery – Department of Surgery
University of Jordan

2. Presentation’s Outline
Introduction
Definition
Anatomy
Natural History
Risk factors
Presentation
Diagnosis
Management
Open repair vs. EVAR
Complications

3. Introduction
Aneurysm and dissection are the most common diseases of the aorta.
Definition : localized or diffuse aortic dilation that exceeds 50% of the normal aortic diameter
Elasticity and tensile strength from the medial layer  contains elastin, collagen, smooth muscle cells, and ground substance Genetic Factors
Cystic medial degeneration  leads to the final common pathway of progressive aortic expansion and eventual rupture
Atherosclerosis : coexisting process rather than the underlying cause.
The vicious cycle  Laplace's law (tension = pressure ´ radius)

4. Location
Ascending
Arch
Descending
Thoracoabdominal

5. Anatomy The proximal aortic segment
Ascending  from aortic valve (and the three sinuses of Valsalva ) till the origin of the innominate artery
Transverse aortic archbrachiocephalic branches
The distal aortic segment
Descending thoracic aorta  distal to left subclavian artery till the diaphragmatic hiatus  multiple bronchial and esophageal branches as well as the segmental intercostal arteries, which provide circulation to the spinal cord.
Abdominal aorta.

6. Natural History and Incidence
No prospective or randomized analyses of the natural history.
Incidence  10/100,000 person-years.
Aortic diameter was a strong predictor of rupture, dissection, and mortality.
Critical diameters 6.0 cm ascending aorta and 7.0 cm descending aorta.

7. Risk Factors Advanced age Hypertension Smoking Bicuspid aortic valve
Connective tissue disorders (Marfan’s)
Infections
Trauma
Male Gender / Family Hx
Diabetes

8. Clinical Manifestations
Asymptomatic
Pain implies sudden extension or rupture of aneurysm 
Ascending aorta - neck, jaw
Descending aorta - back, inter-scapular
Thoracoabdominal aorta - low back
Compression of adjacent structures 
- SVC syndrome 
- Hoarseness, laryngeal nerve
Erosion
Aortic Valve Insufficiency
Distal Embolization
Rupture

9. Complications of aneurysms

10. Diagnosis Hx and P/E Plain Radiographs ECHO CT scan MR Angio
Aortogram and Cardiac Cathetrization

11. Plain Radiographs convexity in the right superior mediastinum
loss of the retrosternal space
widening of the descending thoracic aortic shadow( calcification )

12. Echocardiography

13. CT scan

14. Medical Management Life Style Modification Smoking Cessation
BP Control
Beta-blockade with Propanolol
Periodic Exams
CT if close to surgical threshold

15. Indications for surgery
Ascending
signs of AI
Acute or Chronic Dissection
Rupture
Progressive enlargement
Marfan's pt. with size > 5 cm
More than 6cm
Arch
All symptomatic patients
> 5-6 cm fusiform aneurysms
All pseudoaneurysms
Descending/ Thoracoabdominal
all symptomatic patients
twice the normal size of the aorta or 6 cm.
progressive enlargement (> 1 cm/yr)

16. Aortic Pathology Repair
Healthy aortic valve, annulus, and sinuses of Valsalva  simple dacron graft.

17. Composite valve and graft replacement

18. Bentall technique
The coronary ostia are tightly sutured to openings in the graft.

19. Composite valve and graft replacement .
Composite valve and graft replacement
Thoracic Aorta

20. Aortic arch aneurysms
Deep hypothermic circulatory arrest (HCA) ( antegrade or retrograde cerebral perfusion)
Hemi arch replacement
Total arch replacement
Trifurcated head-vessel attachment graft.

21. Surgical technique for total arch replacement with a branched aortic graft. Following initiation of circulatory arrest.

22. Descending thoracic aortic aneurysm
Type A, distal to the left subclavian artery to the 6th intercostal space. Type B, 6th intercostal space to above the diaphragm (12th intercostal space). Type C, entire descending thoracic aorta, distal to the left subclavian artery to above the diaphragm (12th intercostal space).                                                

23. Descending thoracic aortic aneurysms and thoracoabdominal aneurysms
Either open or endovascular repair.
With or without the use of a bypass circuit
Endovascular stent grafts  Gore-TAG (lt subclavian  celiac).
Thoracoabdominal aneurysms  may be repaired with the use of a partial bypass of the left atrial artery to the femoral artery.
Prevention of paraplegia is one of the principal concerns.

24. Surgical complications
Bleeding
Stroke ( arch repairs ) hypothermic circulatory arrest.
Myocardial infarction
Pulmonary dysfunction
Renal dysfunction
Paraparesis and paraplegia
Endovascular stenting complications : endoleaks, stent fractures, and stent graft migration.

25. OUTCOME AND PROGNOSIS (1) Ascending aneurysms repair mortality  5-10%
(2) Arch aneurysms repair mortality 25%
(3) Descending thoracic aneurysms repair mortality 5-15%,.
(4) GORE-Tag  1.5% 30 day mortality. Temporary or permanent spinal cord paraplegia occurred in 3% of patients and stroke in 4% of patients. At 2 years, aneurysm survival was 97% and overall survival 75%

26. Aortic Pathology Repair

27. Endovascular stents

28. Endovascular stents

29. Aortic Dissection
Tear in the intima of the aorta resulting in blood leaving the normal aortic channel and dissecting through the media producing a false channel
True and false lumens separated by intimal flap
Fenestrations in intimal flap produces flow in both lumens - double barrel aorta
Possible compromised flow to branches of aorta (organs and extremities)
False lumen weakens with time – aneurysm or rupture

30. Proposed mechanisms of initiation of aortic dissection

31. Aortic Dissection Complications
Hospital death: as a consequence of hemorrhage, myocardial infarction, stroke, visceral necrosis, renal failure
Ascending aorta     5-10% (to 30%)
Arch       % (to 50%)
Descending      10% (to 25-60%)

32. Aortic dissection classification based on the site of the intimal tear

33. Aortic Dissection Typically in 50-70 year old men with Hypertension
Connective tissue disorder
Severe pain (90%) :tearing, interscapular, precordial or neck
Aortic Murmur – dissection causing incompetence
Cardiac Tamponade – rupture into pericardium
Signs of occlusion of major branch vessels
Coronary – hypotension and chest pain
Arch - stroke – rarely improves with restoration of flow
Intercostal - paraplegia
Renal - oliguria-anuria
Visceral - acute abdomen
Iliac - ischemic leg – pulse deficit (60%)

34. Diagnosis
Chest X-ray - widened mediastinum, cardiomegaly, pleural effusion
Aortogram
TEE
2-D ECHO - identifies intimal flap/false channel, noninvasive, no contrast media, bedside
CT Scan - identifies intimal flap rapidly, requires contrast media, identifies rupture
Digital Subtraction Angio

35. CXR
Chest radiograph of a patient with aortic dissection. A, The patient's baseline study from 3 years prior to admission, with a normal-appearing aorta. B, The chest radiograph upon admission, which is remarkable for the interval enlargement of the aortic knob (arrow). The patient was found to have a proximal aortic dissection

36. Aortogram
Aortogram in the left oblique view demonstrating proximal aortic dissection and its associated cardiovascular complications. The true lumen (T) and false lumen (F) are separated by the intimal flap (I), which is faintly visible as a radiolucent line following the contour of the pigtail catheter. The true lumen is better opacified than the false lumen, and two planes of the intimal flap can be distinguished (arrows). The branch vessels are opacified, along with marked narrowing of the right carotid artery (CA), which suggests that its lumen is compromised by the dissection

37. TEE
Transesophageal echocardiography of dissection of the ascending aortic aorta in cross-section (A) and saggital color-Doppler mode view demonstrate no flow in the large false lumen (B).

38. 2D-ECHO

39. Type A aortic dissection CT scan
CT scan of type A aortic dissection with intimal flap in the ascending (A) and descending (B) segments of the aorta.

40. Type B aortic dissection
CT scan of type B aortic dissection with normal ascending aorta (A) and multiple partitions of the lumen in the descending thoracic aorta (B)

41. Management of Aortic Dissection
Medical
Uncomplicated Type B
Control pain
Control BP
Surgical
All Type I’s and II’s (Type A)
Complicated type III’s (Type B)
leak, limb or gut ischemia, acute renal failure, paraparesis, uncontrolled pain
Contraindicated in equivocal CNS, advanced age, limiting comorbidities, +/- paraplegia

42. Ascending aortic dissection repair
Ascending aortic dissection repair. A, Proximal tear site, aortic valve inspection, intima and adventitial suture, inner distal anastomosis with pledgeted polypropylene suture reinforcement. B, Outer distal anastomosis with pledgeted polypropylene suture reinforcement, aortic valve resuspension, and proximal reinforced anastomosis.