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Aortic Valve Repair
Aortic Valve Repair Delos M. Cosgrove and Charles D. Fraser Aortic valve repair was one of the first open intracardiac procedures attempted. Although the initial results were somewhat encouraging, this approach to the treatment of aortic valve disease was largely abandoned after the introduction of safe valve prostheses. 1-5 Indeed, the development and widespread clinical application of hoth mechanical and bioprosthetic valves rank as one of the real success stories of modern cardiac surgery. The era of reliable mechanical valve prostheses was initiated after the development of the StarrEdwards ball-and-cage valve in the early 1 9 6 0 ~Con.~ current developments in New Zealand and England by Barratt-Boyes and Ross, respectively, showed the use of homograft or allograft valves for aortic valve replaceme11t.'?~Tremendous advances in structural integrity and hiocompatability occurred over the ensuing deracks and, in the current era, the cardiac surgeon has a variety of mechanical and bioprosthetic valve options available in the treatment of an individual patient. More recently, a resurgence in the use of autologous, pulmonary homograft tissue transplants to the aortic position by using the Ross procedure, so named after its developer, Donald Ross, has added yet another option to the surgical a r m a m e n t a r i ~ r n . ~ ~ ' " Considerable data are available to support the relative safety of aortic valve replacement in a variety of clinical settings."." Furthermore, detailed follow-up data exists for all types of prosthetic and biological valves currently in use that allow surgeons and cardiologists to have a reasonable degree of accuracy in predicting the long-term risks associated with each option in an individual patient. Overall, the long-term risks associ-
SURGICAL TECHNIQUE
Ii 1
ated with having prosthetic or biological aortic valve replawment have been documented to be relatively low. The degree of ongoing risk in an individual patient clearly relates to a constellation of factors, including the type of prosthesis, the necessity for anticoagulation, age, and associated cornorbid factors, such as coronary artery disease and ventricular function. "M' Complications associated with lifelong valvular prostheses may include mechanical failure, thromhoembolism, endocarditis, hemolysis, paravalvular leakage, and anticoagulantrelated hemorrhage. Although the likelihood of any one prosthesis-related complication is low, an individual may still be at some significant lifetime risk when faced with many years of living with a prosthetic aortic valve. After consideration of the ongoing risk associated with aortic valve replacement, we have reexamined the possibility of repairing aortic valves in selected patients with appropriate pathology. Our hypothesis has been that, in patients with certain types of aortic: valve pathology, successful valve repair may afford the individual the opportunity of lower risks of complications associated with having one's own native aortic valve. We have felt particularly compelled to use these techniques in young individuals who face the necessity of aortic valve surgery. In such patients, the potential long duration of needing a valve prosthesis combined with issues regarding lifestyle, desire for childbearing, and level of maturity have led us to work very hard to preserve the patient's native aortic valve, if possible. Further, our increasing level of comfort with cardiac reoperations combined with the relative safety of such procedures has encouraged us to choose valve repair as a palliative intermediate-term step rather than a bioprosthesis in certain young patient^.'^
1
Essential to s valvuloplasty is the cation of causes of aortic insuffi/ ciency. Aortic valve lesions may be \ categorized according to the range of motion of the cusps. Cusp motion may be normal, restricted, or prolapsed. When leaflet motion is normal, aortic insufficiency results from perforation of a cusp or annuRESTRICTED PROLAPSE NORMAL lar dilatation. Aortic insufficiency may be secondary to restricted leaflet motion. This is caused by dilatation of the aorta, particularly at the supra annular ridge, causing restricted motion of the aortic cusps, which prevents central coaptation. Restricted motion may also Le caused by rheumatic valvulitis. This causes leaflet fibrosis anti failure of central coaptation of thr leaflet.
30
>'
Operative Techniques in Cardiac & Thoracic Surgery, Vol 1, N o 1 (July), 1996: pp 30-37
2
By far, the best results for aortic valvuloplasty have occurred in patients with prolapsed leaflet. Prolapsing leaflet may be secondary to aortic dissection. In this situation, the comniissures may be reapproximated and a supra annular graft implanted above it.
3
In more severe cases with extensive dissection of the aortic root, it may be useful to sandwich the layers of the aorta with Teflon felt (C.R. Bard, Bard Vascular, Haverhill, MA).
4
Prolapse of individual leaflets may be seen with tricuspid or bicuspid valves. A particularly interesting group of patients is represented by individuals with prolapse of a single cusp. This is most often seen with the right coronary cusp and has led to the hypothesis that, in some cases, leaflet prolapse may be associated with a pre-existing subaortic ventricular septa1 defect that is spontaneously closed.
32
COSGROVE A N D FRASER
5
Acquired leaflet prolapse is the result of the elongation of the free edge of the aortic: cusp. This may occur when the free edge of the aortic cusp ruptures at the site of a fenestration.
6
A torn remnant of the aortic twsp is seen along the free edge of the cusp with this type of prolapst,.
7
Exposure of the aortic valve is enhanced by placing sutures in the supra annular ridge at each commissure and suspending them from the drapes under tension. This aids greatly in the exposure by elevating the valve and establishing a physiological orientation.
33
AORTIC VALVE REPAIR
9 8
EcIuaI tension on the three sutures also helps in evaluating the relative lengths of the three cusps.
To achieve symmetry, a n equilateral triangle is resected from the center portion of the prolapsing leaflet. The size of the equilateral triangle is determined by the amount of excessive tissue with some allowance for incorporation of tissue into the suture line. Originally, interrupted simple sutures of milltiflament material were used for reapproximation of tissue.
10
This tec-hnique was amended, leaving additional thickened tissiw in the venter portion of the cusp and using continuous douhle-layer running suture to reapproximate the tissue. This has thr advantage of preventing small leaks between the sutures a n d reducing the number of knots and exposed suture tails. The schematic representation of the triangular resection is shown on the left. The niotlifiecl version is shown on the right.
11
Aortic insufficiency is frequently associated with annular dilatation. On the left is the normal coaptation of the cusps and the subvalvular triangle. Annular dilatation results in a widening of this subvalvular triangle with lack of coaptation in the central portion of the leaflet. Placement of horizontal mattress sutures buttressed with Teflon felt reduces the suhvalvular triangle, increasing coaptation a n d reducing the annular circumference.
34
COSGROVE AND FHASER
12
The technique for commissurotoplasty is shown in detail. Horizontal mattress sutures are placed through the annulus at :he base of the cusp, not including cusp tissue. The sutures result in a taller, narrower, interleaflet triangle, and thus, greater leaflet coaptation.
NORMAL
REPAIR (HIGH)
REPAIR (LOW)
13
The depth of placement of sutures directly affects the amount of reduction of the annulus. Suture placement high in the commissure significantly increases the leaflet coaptation and decreases annular circumference. Suture placement lower in the commissure results in a greater leaflet coaptation and increases plication of the annulus.
14
This annular plication is incorporated in the s u r g cal repair of all prolapsing leaflets as the adequacy of coaptation can be appreciated from this intraoperative photograph.
35
AORTIC VALVE REPAIR
I6
The cause of insufficiency in a bicuspid valve is prolapse of the conjoined leaflet. The free edge of the conjoined leaflet is longer than its opposing cusp seen in this intraoperative photograph.
15
A bicuspid aortic valve is the most commonly recognized congtmital cardiac malformation. Although not precisely known, the prevalence of this anomaly is estimated to be between 1% and 2%. The majority of the patients who are born with ii bicuspid valve live a normal life span without pathological process developing in their bicuspid valve. By repairing a hicuspid valve and making it competent, we hope to return our patients to the population of individuals surviving a normal life expectancy without complications of a bicuspid valve. Several mechanisms exist that result in aortic insufficiency in bicuspid valves. The bicuspid valves result from failure of separation of two cusps; this most commonly occurs hetween the right and left coronary cusps. In 60% of the patients, a rudimentary commissure or raphe is present that bisects the conjunct leaflets. This raphe may be the source of restricted leaflet motion o r calcification.
17
It is common that the prolapsing portion of the free edge of the prolapsing cusp is thickmed, which is presumed to be secondary to t h o d flow over this area in diastole. This thickened area serves as a good guide as to the amount of prolapse and marks the edges of the leaflet resection.
36
COSGROVE AND FRASER
18
A triangular resection of the prolapsing leaflet is carried at its midpoint. The completion of this shows equal lengths of the t w o cusps of the aortic valve.
19
To insure additional coaptation reduce the circumference of the valve, annuloplasty is performed at both commissures after the triangular resection of the prolapsing leaflet.
20
The excellent coaptation of the leaflets is shown after placement of annuloplasty sutures in this insufficient bicuspid valve.
COMMENTS A major impediment to aortic valve repair has been determining the mechanism of the insufficiency and evaluating the results of the repair intraoperatively. Intraoperative echocardiography provides tfie diagnostic ability and quality control that enables aortic valvuloplasty to achieve consistently good results. It provides important information about the mechanism of the regurgitation, showing its origin, the direction of the regurgitant jet, the number of leaflets, and their range of motion. The adequacy of repair can be determined under physiological condition immediately after removal of the aortic clamp. If there is persistent regurgitation, it can be quantitated at its site of origin and frequently its cause can be identified.
The technique for correcting cusp prolapse by triangular resection has some theoretical and practical advantages when compared with the technique originally reported by Starr et a12s and popularized by Trusler et al.3 The fact that only one suture line is created reduces the potential for technical failure. No sutures are placed at the point of maximum flexion to interfere with the motion of the valve o r act as a nidus for calcification. In bicuspid valves, the majority of the leaflet thickening and, in some cases, calcification are removed. Recognition of the role of annular dilatation in aortic insufficiency has promoted the development of several ingenious techniques to correct it. Carpentier’s technique26uses continuous circumferential horizontal mattress sutures placed through the annulus. This plicates
37
AORTIC VALVE REPAIR ~
the entire annular circumference, hut the amount of decrease in the annulus has been difficult to judge and control. Encircling the entire annulus has the theoretical disadvantage of reducing its flexibility and making the annulus nondistensive. Annular plication at the rommissure is technically appealing because the area is readily visualized, the amount of annular reduction is easily controlled, and leaflet coaptation is enhanced. Although it has never been shown, it is reasonable to assume that the annular dilatation occurs to a greater extent at the commissures, an area in which there is less obvious annular and fibrous tissue. This phenomenon is apparent in bicuspid valves, in which the leaflet tissue appears to lose its normal coaptation at the point of union with the aorta. Therefore, selected plication of the most affected areas becomes an increasingly rational approach. There is some concern that techniques of aortic valvuloplasty are not readily reproducible, and are therefore not likely to achieve the same level of general clinical application witnessed for prosthetic valve replacement. This skepticism is clearly reminiscent of the early acceptance of atrioventricular valve repair, which has now become the standard of care for many forms of atrioventricular valve disease. Although techniques of aortic valvuloplasty are still evolving, we believe that there is a definite subset of patients who will benefit from the preservation of their native valve. As with atrioventricular valves, recent findings have suggested that the structural integrity of the intact aortic root is important to valve and cardiac f ~ n c t i o n . ‘Whether ~ preserving an intact, functioning bicuspid aortic valve provides long-term advantages to the patient in terms of preserving cardiac function and preventing prosthetic valve-related complications remains to be documented.
REFERENCES I . Taylor WJ, Thrower WB, Blark H , et al: The surgiral corrertion of aortir insufficiency by rircumclusion. J T horar Cardiovasr Surg 35: 192205, 1955 7 Bailey CP. Bolton HE , Jamison WL, et al: Commissurotomy for rheumatic aortic stenosis. 1. Surgery. Circulation 9:22-31, 1954 3. Trusler GA, Moes (A, Kidd BS: Repair of ventricular septal defect with aortic insufficiency. J Thorac Cartliovasc Surg 66:394-403, 1973’ 4. Spencer FC, Bahnson HT, Neil1 CA: T he treatment of aortic regurgitation associated with a ventricular septal defect. J Thorac Cardiovasr Surg 43:222-233, 1962 2. Ellis FH, Ongley PA, Kirklin J W Ventricular septal defect with aortic valvular incompetence. Surgical consideration. Circulation 27:789-795,1962 6. Starr A, Edwards ML: Mitral replacement: Clinical experience with a hall-valve prosthesis. Ann Surg 154:726-740, 1961 7 . Barratt-Boyes BG, Roche AHG, Snhramanyan R, et al: Long-term L.
8. 9. 10.
11. 12.
13.
14
15
16
17.
18.
19.
20. 21,
22.
23.
24.
25.
26. 27.
follow-up of patients with the antiliotic sterilized aortic homograft valve inserted freehand in the aortir position. Cirrulation 753768-777, 1987 Ross DN: Replaremrnt of aortic and mitral valves hy the pulmonary autograft. Lancet 2:956-958, 1967 Matsuki 0, Rohles A, Gibbs S , ct al: Long-term performance of 555 aortir homografts in the aortic position. Ann Thorac Surg 46:187-191,1988 Elkins RC, Santangelo K, Strlzrr P, et al: Pulmonary autograft replacement of the aortic valvr and evolution of technique. J Card Surg 7:108-116, 1992 Lytle BW, Cosgrove DM, Taylor PC: Primary isolated aortic valve replacement. J Thorac Cardiovasc Surg 97:675-694,1989 Cohn LH, Allred EN,DeSesa VJ, et al: Early and late risk of aortic valve replacement. J Thora r Carcliovasc Surg 98:695-792, 1984 Aranki S , Rizzo RJ, Coupe‘ GS, et al: Aortic valve replacement in theelclerly: Effect of gender a nd coronary artrry clisrase on operative mortality. Circulation 5:17-23, 1993 (suppl2) Mitchell RS, Miller DS, Stinson EB, et al: Comparative analysis nf mechanical and bioprosthetic valves after aortir valve replacement. J Thora r Carcliovasc Surg 94:20-33, 1987 Borkon AM, Soule LM, Baughman KL, et al: Comparative analysis of mechanical and hioprosthetir valves after aortic valve replarement. J Thorac Cardiovasc Surg 94:20-33, 1987 Hartz RS, LoCicero J , Kucich V, et al: Comparative study of warfarin versus antiplatelet therapy in patients with a St. Jude Medical valve in the aortic position. J Thorac Cardiovasc Surg 92:684-690, 1986 Cohn LH, Collins JJ, DiSesa VJ, et al: Fifteen year experience with 1678 Hanrock hioprosthetic heart valve replaremeuts. Ann Thorac: Surg 210:435-443, 1989 Jonrs EL, Weintrauh WS, Craver JM, et al: Ten-year experience with the porrine valve: Interrelationship of valvr survival antl patient survival in 1,050 valve replacements. Ann Thorae Surg 49:370-384. 1990 Yarouh MH, Rasmi NRH, Sundt TM, et al: Fourteen year experienre with “Homovital” homografts for anrtir valve rrplarement. J Thorac Cardiovasc Surg 110:186-194, 1995 Chon LH , DiSesa VJ, Collins J J J r : The Hancork modified orifirr bioprosthetic valve: 1976-1988. Ann Thora r Surg 48:81-82, 1989 Bloomfield P, Whratlry DJ, Prrscott RJ, et al: Twelve year romparison of the Bjork-Shiley mechanical heart valve with porrine valve prosthesis. N Engl J Med 324:573-579, 1991 Hammernieister KE, Srthi GK, Henderson WG, et al: A comparison of outcomes in men 11 years after heart valve replarement with a merhanical valve or hioprosthesis. N Engl J Med 328:489-496, 1993 Alberturci M, Wong K, Prtrou M, et al: The use of unstented homograft valves for aortic valve reoperations. Review of a twenty-three year rxperienre. J Thorac Carcliovasc Surg 107: 152.161, 1994 Lytle BW, Cosgrove DM, Taylor PC, et al: Renperationn for valve surgery: Perioperative mortality a nd determinants of risk for 1000 patients, 1958-1984. Ann Thorac Surg 42:632-643, 1986 Sta rr A, Menashe V, Dotter D: Surgiral correction of aortic iusuffirienry associated with ventrirular septal defrct. Surg Gynerol Ohstrt 111:7176, 1960 Carpentier A. Cardiar valve surgery-the “French rorrertion.” J Thora r Cardiovasc: Surg 86:323-337, 1983 Kunzelman KS, Grande KJ, David TE. r t al: Aortic root and valve relationships. Impact on surgiral repair. J Thorar Cardiovasr Surg 107:162-170, 1994
From the Departmrnt of Thoracic and Cardiovascular Surgery, Thr Cleveland Clinic Foundation. Cleveland, OH. Address reprint requests to Delos M. Cosgrove, MD. Chairman, Dept of Thoracic antl Cardiovasrular Surgery, The Cleveland Clinic Fountlation, 9500 Euclic! Ave, Cleveland, OH 44195. Copyright 0 1996 by W.R. Saunders Company
1085-5637/96/0101-0004$5.00/0
SURGICAL TECHNIQUE
Ii 1
ated with having prosthetic or biological aortic valve replawment have been documented to be relatively low. The degree of ongoing risk in an individual patient clearly relates to a constellation of factors, including the type of prosthesis, the necessity for anticoagulation, age, and associated cornorbid factors, such as coronary artery disease and ventricular function. "M' Complications associated with lifelong valvular prostheses may include mechanical failure, thromhoembolism, endocarditis, hemolysis, paravalvular leakage, and anticoagulantrelated hemorrhage. Although the likelihood of any one prosthesis-related complication is low, an individual may still be at some significant lifetime risk when faced with many years of living with a prosthetic aortic valve. After consideration of the ongoing risk associated with aortic valve replacement, we have reexamined the possibility of repairing aortic valves in selected patients with appropriate pathology. Our hypothesis has been that, in patients with certain types of aortic: valve pathology, successful valve repair may afford the individual the opportunity of lower risks of complications associated with having one's own native aortic valve. We have felt particularly compelled to use these techniques in young individuals who face the necessity of aortic valve surgery. In such patients, the potential long duration of needing a valve prosthesis combined with issues regarding lifestyle, desire for childbearing, and level of maturity have led us to work very hard to preserve the patient's native aortic valve, if possible. Further, our increasing level of comfort with cardiac reoperations combined with the relative safety of such procedures has encouraged us to choose valve repair as a palliative intermediate-term step rather than a bioprosthesis in certain young patient^.'^
1
Essential to s valvuloplasty is the cation of causes of aortic insuffi/ ciency. Aortic valve lesions may be \ categorized according to the range of motion of the cusps. Cusp motion may be normal, restricted, or prolapsed. When leaflet motion is normal, aortic insufficiency results from perforation of a cusp or annuRESTRICTED PROLAPSE NORMAL lar dilatation. Aortic insufficiency may be secondary to restricted leaflet motion. This is caused by dilatation of the aorta, particularly at the supra annular ridge, causing restricted motion of the aortic cusps, which prevents central coaptation. Restricted motion may also Le caused by rheumatic valvulitis. This causes leaflet fibrosis anti failure of central coaptation of thr leaflet.
30
>'
Operative Techniques in Cardiac & Thoracic Surgery, Vol 1, N o 1 (July), 1996: pp 30-37
2
By far, the best results for aortic valvuloplasty have occurred in patients with prolapsed leaflet. Prolapsing leaflet may be secondary to aortic dissection. In this situation, the comniissures may be reapproximated and a supra annular graft implanted above it.
3
In more severe cases with extensive dissection of the aortic root, it may be useful to sandwich the layers of the aorta with Teflon felt (C.R. Bard, Bard Vascular, Haverhill, MA).
4
Prolapse of individual leaflets may be seen with tricuspid or bicuspid valves. A particularly interesting group of patients is represented by individuals with prolapse of a single cusp. This is most often seen with the right coronary cusp and has led to the hypothesis that, in some cases, leaflet prolapse may be associated with a pre-existing subaortic ventricular septa1 defect that is spontaneously closed.
32
COSGROVE A N D FRASER
5
Acquired leaflet prolapse is the result of the elongation of the free edge of the aortic: cusp. This may occur when the free edge of the aortic cusp ruptures at the site of a fenestration.
6
A torn remnant of the aortic twsp is seen along the free edge of the cusp with this type of prolapst,.
7
Exposure of the aortic valve is enhanced by placing sutures in the supra annular ridge at each commissure and suspending them from the drapes under tension. This aids greatly in the exposure by elevating the valve and establishing a physiological orientation.
33
AORTIC VALVE REPAIR
9 8
EcIuaI tension on the three sutures also helps in evaluating the relative lengths of the three cusps.
To achieve symmetry, a n equilateral triangle is resected from the center portion of the prolapsing leaflet. The size of the equilateral triangle is determined by the amount of excessive tissue with some allowance for incorporation of tissue into the suture line. Originally, interrupted simple sutures of milltiflament material were used for reapproximation of tissue.
10
This tec-hnique was amended, leaving additional thickened tissiw in the venter portion of the cusp and using continuous douhle-layer running suture to reapproximate the tissue. This has thr advantage of preventing small leaks between the sutures a n d reducing the number of knots and exposed suture tails. The schematic representation of the triangular resection is shown on the left. The niotlifiecl version is shown on the right.
11
Aortic insufficiency is frequently associated with annular dilatation. On the left is the normal coaptation of the cusps and the subvalvular triangle. Annular dilatation results in a widening of this subvalvular triangle with lack of coaptation in the central portion of the leaflet. Placement of horizontal mattress sutures buttressed with Teflon felt reduces the suhvalvular triangle, increasing coaptation a n d reducing the annular circumference.
34
COSGROVE AND FHASER
12
The technique for commissurotoplasty is shown in detail. Horizontal mattress sutures are placed through the annulus at :he base of the cusp, not including cusp tissue. The sutures result in a taller, narrower, interleaflet triangle, and thus, greater leaflet coaptation.
NORMAL
REPAIR (HIGH)
REPAIR (LOW)
13
The depth of placement of sutures directly affects the amount of reduction of the annulus. Suture placement high in the commissure significantly increases the leaflet coaptation and decreases annular circumference. Suture placement lower in the commissure results in a greater leaflet coaptation and increases plication of the annulus.
14
This annular plication is incorporated in the s u r g cal repair of all prolapsing leaflets as the adequacy of coaptation can be appreciated from this intraoperative photograph.
35
AORTIC VALVE REPAIR
I6
The cause of insufficiency in a bicuspid valve is prolapse of the conjoined leaflet. The free edge of the conjoined leaflet is longer than its opposing cusp seen in this intraoperative photograph.
15
A bicuspid aortic valve is the most commonly recognized congtmital cardiac malformation. Although not precisely known, the prevalence of this anomaly is estimated to be between 1% and 2%. The majority of the patients who are born with ii bicuspid valve live a normal life span without pathological process developing in their bicuspid valve. By repairing a hicuspid valve and making it competent, we hope to return our patients to the population of individuals surviving a normal life expectancy without complications of a bicuspid valve. Several mechanisms exist that result in aortic insufficiency in bicuspid valves. The bicuspid valves result from failure of separation of two cusps; this most commonly occurs hetween the right and left coronary cusps. In 60% of the patients, a rudimentary commissure or raphe is present that bisects the conjunct leaflets. This raphe may be the source of restricted leaflet motion o r calcification.
17
It is common that the prolapsing portion of the free edge of the prolapsing cusp is thickmed, which is presumed to be secondary to t h o d flow over this area in diastole. This thickened area serves as a good guide as to the amount of prolapse and marks the edges of the leaflet resection.
36
COSGROVE AND FRASER
18
A triangular resection of the prolapsing leaflet is carried at its midpoint. The completion of this shows equal lengths of the t w o cusps of the aortic valve.
19
To insure additional coaptation reduce the circumference of the valve, annuloplasty is performed at both commissures after the triangular resection of the prolapsing leaflet.
20
The excellent coaptation of the leaflets is shown after placement of annuloplasty sutures in this insufficient bicuspid valve.
COMMENTS A major impediment to aortic valve repair has been determining the mechanism of the insufficiency and evaluating the results of the repair intraoperatively. Intraoperative echocardiography provides tfie diagnostic ability and quality control that enables aortic valvuloplasty to achieve consistently good results. It provides important information about the mechanism of the regurgitation, showing its origin, the direction of the regurgitant jet, the number of leaflets, and their range of motion. The adequacy of repair can be determined under physiological condition immediately after removal of the aortic clamp. If there is persistent regurgitation, it can be quantitated at its site of origin and frequently its cause can be identified.
The technique for correcting cusp prolapse by triangular resection has some theoretical and practical advantages when compared with the technique originally reported by Starr et a12s and popularized by Trusler et al.3 The fact that only one suture line is created reduces the potential for technical failure. No sutures are placed at the point of maximum flexion to interfere with the motion of the valve o r act as a nidus for calcification. In bicuspid valves, the majority of the leaflet thickening and, in some cases, calcification are removed. Recognition of the role of annular dilatation in aortic insufficiency has promoted the development of several ingenious techniques to correct it. Carpentier’s technique26uses continuous circumferential horizontal mattress sutures placed through the annulus. This plicates
37
AORTIC VALVE REPAIR ~
the entire annular circumference, hut the amount of decrease in the annulus has been difficult to judge and control. Encircling the entire annulus has the theoretical disadvantage of reducing its flexibility and making the annulus nondistensive. Annular plication at the rommissure is technically appealing because the area is readily visualized, the amount of annular reduction is easily controlled, and leaflet coaptation is enhanced. Although it has never been shown, it is reasonable to assume that the annular dilatation occurs to a greater extent at the commissures, an area in which there is less obvious annular and fibrous tissue. This phenomenon is apparent in bicuspid valves, in which the leaflet tissue appears to lose its normal coaptation at the point of union with the aorta. Therefore, selected plication of the most affected areas becomes an increasingly rational approach. There is some concern that techniques of aortic valvuloplasty are not readily reproducible, and are therefore not likely to achieve the same level of general clinical application witnessed for prosthetic valve replacement. This skepticism is clearly reminiscent of the early acceptance of atrioventricular valve repair, which has now become the standard of care for many forms of atrioventricular valve disease. Although techniques of aortic valvuloplasty are still evolving, we believe that there is a definite subset of patients who will benefit from the preservation of their native valve. As with atrioventricular valves, recent findings have suggested that the structural integrity of the intact aortic root is important to valve and cardiac f ~ n c t i o n . ‘Whether ~ preserving an intact, functioning bicuspid aortic valve provides long-term advantages to the patient in terms of preserving cardiac function and preventing prosthetic valve-related complications remains to be documented.
REFERENCES I . Taylor WJ, Thrower WB, Blark H , et al: The surgiral corrertion of aortir insufficiency by rircumclusion. J T horar Cardiovasr Surg 35: 192205, 1955 7 Bailey CP. Bolton HE , Jamison WL, et al: Commissurotomy for rheumatic aortic stenosis. 1. Surgery. Circulation 9:22-31, 1954 3. Trusler GA, Moes (A, Kidd BS: Repair of ventricular septal defect with aortic insufficiency. J Thorac Cartliovasc Surg 66:394-403, 1973’ 4. Spencer FC, Bahnson HT, Neil1 CA: T he treatment of aortic regurgitation associated with a ventricular septal defect. J Thorac Cardiovasr Surg 43:222-233, 1962 2. Ellis FH, Ongley PA, Kirklin J W Ventricular septal defect with aortic valvular incompetence. Surgical consideration. Circulation 27:789-795,1962 6. Starr A, Edwards ML: Mitral replacement: Clinical experience with a hall-valve prosthesis. Ann Surg 154:726-740, 1961 7 . Barratt-Boyes BG, Roche AHG, Snhramanyan R, et al: Long-term L.
8. 9. 10.
11. 12.
13.
14
15
16
17.
18.
19.
20. 21,
22.
23.
24.
25.
26. 27.
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From the Departmrnt of Thoracic and Cardiovascular Surgery, Thr Cleveland Clinic Foundation. Cleveland, OH. Address reprint requests to Delos M. Cosgrove, MD. Chairman, Dept of Thoracic antl Cardiovasrular Surgery, The Cleveland Clinic Fountlation, 9500 Euclic! Ave, Cleveland, OH 44195. Copyright 0 1996 by W.R. Saunders Company
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