Abstract
Aortic valve repair has been shown to yield good outcomes for select patients when performed by trained surgeons. In this chapter, we will discuss the surgical anatomy of the aortic valve, the surgical steps to aortic valve repair, as well as the pre-, intra-, and postoperative considerations that need to be addressed for a successful repair.
Keywords
aortic valve, repair, aortic valve surgery, cardiac surgery
Step 1
Introductory Considerations
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Aortic valve repair (AVr) has been shown to have a lower rate of valve-related complications compared to aortic valve replacement (AVR).
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It is especially beneficial for those in the younger age group due to a higher rate of bioprosthetic degeneration in the case of AVR and the cumulative risk of thromboembolism and bleeding in mechanical aortic valves.
Step 2
Surgical Anatomy
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The aortic valve (AV) is comprised of the functional aortic annulus and cusps.
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The functional aortic annulus is comprised of the sinotubular junction (STJ) and ventriculoaortic junction (VAJ ; Fig. 12.1 ).
Figure 12.1
(A) Aortic valve anatomy. (B) Ventriculoatrial junction.
B, From Boodhwani M, El Khoury G: Aortic valve repair. Operative techniques in thoracic and cardiovascular surgery. 2009.
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The basal ring is the plane that passes through the nadir of the aortic cusps.
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At the right noncoronary commissure, the membranous septum is the border of dissection for the VAJ. At the left-right coronary commissure, the ventricular muscle is the border for VAJ dissection. These anatomic borders illustrate why the VAJ does not reach the basal ring.
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The VAJ level approximates the basal ring level at the noncoronary sinus (NCS), noncoronary left commissure, and left coronary sinus (LCS).
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The aortic cusp geometric height is the maximum tissue height. The effective height measures from the basal ring plane to the level of the central coaptation of the cusps ( Fig. 12.2 ). The noncoronary cusp (NCC) is higher than the right coronary cusp (RCC) and left coronary cusp (LCC).
Figure 12.2
The coaptation height and length and geometric height of the AV leaflets.
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The AV cusp coaptation normally occurs at the midlevel, between the STJ and VAJ. Effective cusp coaptation length is 2 to 6 mm.
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Cusp mobility is a function of the free margin length in relation to the length of annular cusp insertion. These lengths are adjusted appropriately during a repair to reestablish valve competency while ensuring good mobility.
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Alteration in one component of the AV leads to alteration in the others. Each component should be seen in relation to the others.
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A repair-oriented classification of aortic insufficiency (AI) has been developed to guide patient selection and treatment ( Fig. 12.3 ).
Figure 12.3
Functional classification of aortic valve insufficiency.
From Boodhwani M, El Khoury G: Aortic valve repair. Oper Tech Thorac Cardiovasc Surg . 2009.
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Various forms of cusp division and fusion can occur, resulting in unicuspid, bicuspid, and quadricuspid anomalies, which may be associated with aortopathy and congenital cardiac diseases.
Step 2
Surgical Anatomy
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The aortic valve (AV) is comprised of the functional aortic annulus and cusps.
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The functional aortic annulus is comprised of the sinotubular junction (STJ) and ventriculoaortic junction (VAJ ; Fig. 12.1 ).
Figure 12.1
(A) Aortic valve anatomy. (B) Ventriculoatrial junction.
B, From Boodhwani M, El Khoury G: Aortic valve repair. Operative techniques in thoracic and cardiovascular surgery. 2009.
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The basal ring is the plane that passes through the nadir of the aortic cusps.
- ◆
At the right noncoronary commissure, the membranous septum is the border of dissection for the VAJ. At the left-right coronary commissure, the ventricular muscle is the border for VAJ dissection. These anatomic borders illustrate why the VAJ does not reach the basal ring.
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The VAJ level approximates the basal ring level at the noncoronary sinus (NCS), noncoronary left commissure, and left coronary sinus (LCS).
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The aortic cusp geometric height is the maximum tissue height. The effective height measures from the basal ring plane to the level of the central coaptation of the cusps ( Fig. 12.2 ). The noncoronary cusp (NCC) is higher than the right coronary cusp (RCC) and left coronary cusp (LCC).
Figure 12.2
The coaptation height and length and geometric height of the AV leaflets.
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The AV cusp coaptation normally occurs at the midlevel, between the STJ and VAJ. Effective cusp coaptation length is 2 to 6 mm.
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Cusp mobility is a function of the free margin length in relation to the length of annular cusp insertion. These lengths are adjusted appropriately during a repair to reestablish valve competency while ensuring good mobility.
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Alteration in one component of the AV leads to alteration in the others. Each component should be seen in relation to the others.
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A repair-oriented classification of aortic insufficiency (AI) has been developed to guide patient selection and treatment ( Fig. 12.3 ).
Figure 12.3
Functional classification of aortic valve insufficiency.
From Boodhwani M, El Khoury G: Aortic valve repair. Oper Tech Thorac Cardiovasc Surg . 2009.
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Various forms of cusp division and fusion can occur, resulting in unicuspid, bicuspid, and quadricuspid anomalies, which may be associated with aortopathy and congenital cardiac diseases.
Step 3
Preoperative Considerations
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The most common cause of AI is dilation of the functional aortic annulus. Thus, a focused history on the presence of hypertension, family aortic and connective tissue disorders, and the acuity of signs and symptoms will help with management. A history of infective endocarditis, or rheumatic heart disease or the presence of myxomatous mitral disease may infrequently be associated.
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Preoperative echocardiography (echo) is essential for identifying the cause of the AI and will help guide the intraoperative evaluation. It should be able to demonstrate the aortic root and ascending aorta dimensions. The echocardiogram will also be able to show the anatomy of the cusps and the presence of prolapse, fenestrations, bands, calcifications, and vegetations. The quality and direction of the AI jet should also be examined.
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Cusp prolapse occurs when one or more cusps coapt below the normal height of coaptation, at the midheight of the sinus of Valsalva. The presence of an eccentric jet is a sensitive indicator of prolapse. The presence of a fibrous band is a very specific sign of cusp prolapse and identifies the prolapsing cusp ( Fig. 12.4 ).
Figure 12.4
Transeosphageal echocardiographic images. (A) Eccentric aortic insufficiency jet. (B) Cusp prolapse and fibrous band (white arrow) . (C) Fibrous band (white arrow) . (D) Fibrous band (black arrow) .
From Assessment and repair of aortic valve cusp prolapse: implications for valve-sparing procedure. J Thorac Cardiovasc Surg 2011;141:917-25.
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In patients in whom the aortic dimensions are borderline, a preoperative chest computed tomography (CT) scan will aid in a more definitive measurement of the dimensions.
Step 4
Operative Steps
1
Surgery
Isolated Aortic Insufficiency
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A transverse aortotomy is performed, 1 cm from the STJ, leaving 2 to 3 cm of posterior aorta intact. The distal aorta is retracted cephalad for a better exposure of the AV; 4-0 polypropylene sutures are placed at the level of each commissure ( Fig. 12.5 ).
Figure 12.5
Aortic valve exposure using axial traction.
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Axial traction (perpendicular to the annular plane) is placed on the commissural retraction sutures to assess the AV. The AV anatomy is thoroughly examined, including the cusp coaptation, amount of excess tissue, leaflet mobility, presence of restrictions and calcifications, and bands. The characteristic of the aortic sinuses are likewise examined for suggestions of aneurysmal degeneration such as wall thinning and coronary ostia displacement ( ).
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A prolapsing cusp can be identified by the presence of excess free margin length and, occasionally, a transverse fibrous band.
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Radial traction (parallel to the annular plane) is then applied to the commissural stitches, and the center of the cusp free margin is pushed gently to the left ventricle. A nonprolapsing cusp will remain at the physiologic level, which is halfway between the cusp base and its maximal height at the commissure. A prolapsing cusp will be able to be pushed lower into the left ventricle due to excessive amounts of tissue.
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Cusp repair is then performed using free margin plication or resuspension or both. Annular stabilization can be performed with a subcommissural annuloplasty (SCA) or external or internal ring.
Cusp Prolapse Repair
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A 7-0 polypropylene suture is passed through the center of the two nonprolapsing cusps which will serve as reference. Gentle axial traction is applied to the reference cusps, and the prolapsing cusp is pulled parallel to the reference cusp. A 6-0 polypropylene suture is passed through the prolapsing cusp from the aortic to the ventricular side, where it meets the center of the reference cusp. The direction of traction is then reversed, and the same suture is passed from the ventricular to the aortic side at the point where it meets the middle of the reference cusp. This excess free margin is then plicated by tying the suture with the excess tissue on the aortic side. Further plication is done until it is 5 to 10 mm onto the body of the aortic cusp, using interrupted or running locked 6-0 polypropylene sutures. Significant excessive tissue may be resected before the plication ( Fig. 12.6 ; ).
