Chapter 76 - TAAA introduction

Question 1

Frequency of thoracic aortic aneurysms

Answer 1

Ascending 40% Descending 35% Arch 15% Thoracoabdominal 10%

Question 2

Mean thoracic aortic diameter by anatomic region

Answer 2

Ascending 3cm arch 2.5-3.5 cm descending 2-2.3 cm thoracoabdominal 1.7-2.6 cm

Question 3

growth rate of TAAA

Answer 3

1.9-3.4 mm/year < 5 cm: 1.7/year > 5cm: 7.9/mm/year rupture > 7 cm/year

Question 4

male vs female normal thoracic aortic size

Answer 4

2-3 mm bigger in men

Question 5

Epidemiology of TAAA age and gender

Answer 5

65 years average male 1.7x more 6x more male if age > 75

Question 6

Percentage of TAAA with first degree relative with aneurysms

Answer 6

20%

Question 7

Risk factors of TAAA

Answer 7

1) hypertension diastolic > 100 mmhg 2) 20% due to dissection

Question 8

Percentage of TBAD that required subsequent repair

Answer 8

28-40%

Question 9

Predictive factor of TBAD needing subsequent repair

Answer 9

initial aortic diameter > 3.5 cm

Question 10

Protective factor against needing repair after TBAD

Answer 10

false lumen thrombosis at discharge

Question 11

Rate of reoperation in Marfan patients

Answer 11

20% at 5 years

Question 12

Mechanisms responsible for familial thoracic aortic aneurysm and dissection

Answer 12

1) TAAD2 (TFGBR2 mutation) 2) 16p (MYH11 gene) 3) TAAD4 (ACTA2 gene) aortic wall building block of actin myosin mutated

Question 13

5 year survival of a 6cm TAAA and annual rupture risk and annual death risk

Answer 13

54% alive at 5 years 3.7%/year rupture 12%/year death

Question 14

Risk factors for TAAA rupture

Answer 14

1) COPD 3.6x 2) age 2.6 3) pain 2.3 4) aortic diameter 1.5-1.9x

Question 15

Estimated annual event rate (rupture or dissection) based on aortic diameter

Answer 15

50mm: < 1% 50-60 mm: 2.7-8.1% > 60 mm: 37.5-62.5% > 80 mm: 80%

Question 16

Composition difference of ascending vs descending aorta

Answer 16

More elastin in ascending media thicker in ascending

Question 17

MMPs responsible for TAAA formation

Answer 17

MMP2, MMP9

Question 18

Causes of TAAA

Answer 18

1) medial degeneration 80% 2) dissection 15-20% 3) connective tissue disorder (MS, EDS, LDS) 4) infection 2% 5) post-op pseudoaneurysm <1% 6) traumatic < 1%

Question 19

Aortitis that cause TAAA

Answer 19

1) takayasu 2) GCA 3) RA 4) ankylosing spondylitis 5) Reiter syndrome 6) polychondritis

Question 20

Reiter syndrome triad

Answer 20

Reactive arthritis after UG or GI infection 1) urethritis 2) arthritis 3) conjunctivitis

Question 21

Crawford classification of TAAA

Answer 21

FIGURE 76.5 TYPE 1: 25% - entire descending + upper AAA TYPE 2: 30% - entire descending and entire AAA TYPE 3: <25% - descending under T6 and entire AAA TYPE 4: < 25% - abdominal visceral and renal arteries TYPE 5: descending under T6 + upper AAA

Question 22

Physical exam needed for TAAA

Answer 22

1) pressure differential upper and lower 2) visceral ischemia 3) neural deficit 4) murmur of aortic regurg 5) bruits 6) cardiac tamponade

Question 23

TAAA patients that will also have AAA

Answer 23

20-30%

Question 24

TAAA region definition

Answer 24

Distal to left subclavian until aortic bifurcation

Question 25

Synchronous proximal ascending and arch aneurysm in TAAA

Answer 25

6-13%

Question 26

Marfan with type A dissection, how many will need TAAA repaired subsequently

Answer 26

27% more common in DeBakey I

Question 27

CXR for diagnosing TAAA

Answer 27

Widened mediastinum in 64-71% specificity of widened mediastinum is 86%

Question 28

MRI pro/con in TAAA

Answer 28

1) better contrast resolution 2) poorer spatial resolution 3) identifies patency of visceral and renal vessels 4) thrombus and calcium not well displayed

Question 29

Medical management of TAAA

Answer 29

Extrapolated from ascending or abdominal work 1) BP management with beta blocker + ACEi or ARB 2) smk cessation 3) periodic imaging

Question 30

BP target in TAAA

Answer 30

< 140/90 diabetes or CKD < 130/80

Question 31

Betablocker in TAAA

Answer 31

Help marfan to reduce dissection by reducing force of myocardial contraction dP/dt not clear in degenerative TAAA but use anyway

Question 32

ACEI and ARB in TAAA

Answer 32

Evidence of ARB in reducing reactive oxygen species in marfan patients especially losartan to modulate TGF beta mediated signalling

Question 33

Statin in TAAA

Answer 33

no clear evidence may reduce NADH/NADPH oxidase and thereby reduce formation of TAAA use anyway for other benefits

Question 34

Size criteria to indicate elective repair in TAAA

Answer 34

Controversial Guideline: 1) chronic dissection without comorbidity > 5.5 cm for open repair 2) degenerative/traumatic aneurysm > 5.5 cm, saccular or post-op - ENDO 3) end organ failure then treat 4) no ENDO option, high morbidity > 6 cm 5) connective tissue disorder lowers the threshold

Question 35

Patterson mortality calculation after TEVAR

Answer 35

TABLE 76.9

Question 36

Preoperative evaluation for TAAA repair

Answer 36

1) Coronary investigation - if severe then treat first (if stable then unclear) 2) PFT, holter, carotid duplex, EEG, neurocognitive test

Question 37

Coronary revasc before TAAA consideratiosn

Answer 37

1) stenting with DES requires > 6 months of DAPT 2) LIMA not used as it serves as spinal perfusion

Question 38

Dysphagia lusoria

Answer 38

Dysphagia due to aberrant right subclavian artery

Question 39

Kommerell diverticulum

Answer 39

aneurysm of the aberrant right subclavian artery