test 5 aortic stenosis, insufficiency, and aortic procedures

Question 1

Aortic Stenosis

Answer 1

 Congenital AS -10% of all congenital heart diseases
 ACYANOTIC lesion
 Narrowing of the aortic valve or thickening of the
leaflets, bicuspid or unicuspid valve
 Associated with PDA, MS, or Coarctation
 Causes increase in pressure/tension within the LV
 Develop left ventricular hypertrophy
 Decreased ventricular function
 Myocardial ischemia
- High risk for sudden cardiac death

Question 2

Types of Aortic Stenosis

Answer 2

 Supravalvular
 Subvalvular
 Critical Aortic Stenosis

Question 3

Supravalvular Aortic Stenosis

Answer 3

 Constriction of the aorta just above the valve due to fibrous membrane or hypoplastic aortic arch
 Uncommon
 Seen in patients with Williams Syndrome
 Condition with variety of medical and developmental problems
 Can lead to LV hypertrophy, LV dysfunction, ischemia and risk of sudden death

Question 4

Supravalvular Aortic Stenosis Correction

Answer 4

 Aorta is incised into each sinus of Valsalva
 Counter incision is made in the aorta above the obstruction
 Stenotic segment is removed
 2 segments are interdigitated
 CPB is short to moderate

Question 5

When taking out the stenotic portion of the supravalvular aortic stenosis, how do they make the incisions?

Answer 5

• They do not cut straight across the aorta, they cut both sides of the aorta into zigzag
• Do this because they are young and going to grow
• Less chance of constriction with this pattern.

Question 6

Subaortic Aortic Stenosis

Answer 6

 Rare in infancy
 Presents as:
         Fibromuscular stenosis
         Hypertrophic Obstructive Cardiomyopathy
 In infancy usually associated with Coarctation or interrupted aortic arch
 Can lead to LV hypertrophy
         Arrhythmias
         Sudden death

Question 7

Subaortic Aortic Stenosis Correction

Answer 7

 Done when obstruction is moderate to severe (gradient determines)
 Aorta is opened just above the AV
 Leaflets are retracted to expose the obstructive tissue below the valve
 As much obstructive tissue as possible is excised (muscle bundle resection)
 Careful to avoid damage to mitral valve, AV conduction system, or AV leaflets.
 CPB is short

Question 8

Subvalvular obstruction

Answer 8

 Aortic valve annular hypoplasia and subvalvular obstruction
 Cannot just replace the valve - must enlarge the annulus

Question 9

Konno Procedure

Answer 9

 Often done with Ross Procedure
 Aortic Valve removed
 Incision made into ventricular septum (to Left of right coronary ostia)
 Patched open to WIDEN LVOT
 Allows placement of larger graft/prosthetic valve
 Replace aortic root with cryopreserved homograft or pulmonary autograft
 Insert into newly opened LV outflow tract.

Question 10

Critical Aortic Stenosis

Answer 10

 Severe form of congenital AS
 Presents in neonatal period
 Symptoms become more acute as the PDA closes
         Severity depends on degree of obstruction
 Valve may be bicuspid or unicuspid
 LV abnormalities can occur
         Dilation, decreased function
- Early surgical intervention required

Question 11

Critical Aortic Stenosis Correction

Answer 11

 Goal of correction – to relieve obstruction of flow of blood through the aortic valve without causing AI
 Can do percutaneous balloon valvotomy
 Surgery – AV visualized and incised at the commissures
 Commissurotomy may be hard due to abnormal valve development (shape is a factor)

Question 12

Critical Aortic Stenosis Post operative course

Answer 12

 Depends on the degree of LV dysfunction preoperatively (ECMO-VAD)
 Depends on the success of the procedure
 Will most likely require an aortic valve replacement later in life
 Length of stay: 1-3 weeks

Question 13

Aortic Insufficiency and symptoms

Answer 13

 Aortic valve fails to close completely immediately after systole
 Symptoms:
 LV dilation
 Decreased CO
 CHF
 Exercise intolerance, Dyspnea on Exertion, Dizziness, Pulsating headaches, increased pulse pressure, pulmonary congestion, edema

Question 14

Ross Procedure

Answer 14

 Aortic Valve Replacement
 Use patient’s own pulmonary valve
 Move to the Aortic Position
 RVOT is reconstructed with a pulmonary homograft
 Coronary arteries are re-implanted on the autograft
 Follow up studies show the pulmonary autograft grows!!!!!!!!
 THE ONLY AORTIC VALVE REPLACEMENT OPTION TO DO SO
 Makes this the AVR procedure of choice for small children/ pediatrics (rough in adults)
 Starting to become popular in young adult population as well.
- No anticoagulation required post op

Question 15

Ross Procedure process

Answer 15

 Valves visually inspected
 Ensure suitability (pt. selection is key)
 Pulmonary Valve excised
 Aortic valve excised
 Leave coronary arteries as buttons
 Done as root replacement
 Proximal pulmonary autograft put in position of native aortic root
 Coronaries re-implanted
 Distal end connected to aorta
 Cryopreserved Homograft (with intact valve) inserted into original pulmonary root position.

Question 16

Drawbacks of the Ross Procedure

Answer 16

 More extensive procedure/ operation that just an AVR
 Usually required to replace the pulmonary homograft later in life
 Patient growth
 Degeneration of graft

Question 17

Ross Procedure Bypass considerations

Answer 17

 Cannulation
 Aortic
 Venous: Bicaval OR single venous
 Single will allow some air into the venous line
 Cardioplegia
 Antegrade arresting dose
 Retrograde maintenance doses
 Hypothermia
 28oC
 CPB Length: Moderate to long (2 to 3 hours)