Ann Thorac Surg 2008;85:946-948. doi:10.1016/j.athoracsur.2007.10.037
© 2008 The Society of Thoracic Surgeons
Original Articles: Cardiovascular
Single Cusp Replacement for Aortic Regurgitation
Liang Tao, MDa,b,
Xiang Jun Zeng, MD, PhDa,b,*,
Yeong Phang Lim, MDa,b
a Cardiac Surgical Department, Wuhan Asia Heart Hospital, WuHan, China
b Cardiothoracic Surgical Department, Singapore National Heart Center, Singapore
Accepted for publication October 9, 2007.
* Address correspondence to Dr Zeng, WuHan Asia Heart Hospital, WuHan, 430022, China (Email: xiangjunzeng{at}163.com).
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Abstract
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Background: Aortic insufficiency is a commmon disease in cardiac surgery. The frequency of native aortic valve repair in the young is increasing, reflecting a lack of consensus on the optimal therapeutic solution from the growing number of mechanical and biological prostheses.
Methods: Bovine pericardium was used to replace the coronary leaflet to treat aortic insufficiency in 21 patients aged 4 to 39 years (19 ± 9.2). Aortic insufficiency was severe in 18 patients and moderate to severe in 3 patients. Seventeen patents had ventricular septal defects (VSD). One had associated rupture of the right sinus of Valsalva without VSD and 3 other patients had acquired heart disease (1 had infective endocarditis and 2 had rheumatic heart disease).
Results: There was no mortality. The follow-up ranged from 6 to 21 months. Thirteen patients had complete relief of aortic insufficiency, 7 had mild residual aortic insufficiency, and 1 had moderate aortic insufficiency.
Conclusions: Replacement of the diseased leaflet with bovine pericardium is a promising technique for young patients. The short-term outcomes are encouraging, but longer follow-up is required to assess the durability and function of bovine pericardial leaflet in the aortic position.
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Introduction
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Aortic insufficiency (AI) is commonly associated with ventricular septal defect (VSD), especially a subarterial VSD. The frequency of native aortic valve repair in the young is increasing, reflecting a lack of consensus on the optimal therapeutic solution from the growing number of mechanical and biological prostheses. Furthermore, enthusiasm for the Ross pulmonary autograft operation was dampened in some centers when longer follow-up showed that there were issues such as potential double semilunar valve disease, neoaortic insufficiency, future right ventricular outflow tract homograft reintervention, and risk of aortic root reoperation [1–3]. Recently, Odim and colleagues [4] reported the results of a glutaraldehyde-preserved autologous pericardial leaflet extension for repairing the aortic valve. This report reviews our initial experience of replacing the pathologic aortic leaflet with bovine pericardium to repair aortic valve with AI and unileaflet pathology.
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Patients and Methods
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Patients
These patients consented to this operation, and they were informed that this was a new operation. The Ethics Committee approved the procedure.
From September 2005 to December 2006, aortic valvuloplasty was performed in 21 patients, using bovine pericardium. There were 16 men and 5 women. Their mean age was 19 ± 9.2 years (range, 4 to 39), and their mean weight was 45 ± 15.3 kg (range, 16.5 to 66 kg). All 21 patients underwent transthoracic and transesophageal echocardiography. Three patients had moderate to severe AI, and 18 had severe AI. Seventeen patients had been diagnosed with a VSD; the diameter of VSD was 8.7 ± 3.1 mm (range, 4 to 15 mm). One had associated rupture of the right sinus of Valsalva. At the time of operation, 10 patients were classified in New York Heart Association (NYHA) functional class I, 10 patients were in NYHA class II, and 1 was in NYHA class III. The mean diastolic pressure was 50.1 ± 5.3 mm Hg (range, 45 to 60 mm Hg), mean systolic pressure was 120.2 ± 17.2 mm Hg (range, 100 to 165 mm Hg), and mean pulse pressure was 70 ± 25 mm Hg (range, 45 to 115 mm Hg). The mean left ventricular end-diastolic diameter was 67.3 ± 11.6 mm (range, 51 to 101 mm). The mean left ventricular end-systolic diameter was 45.2 ± 10.5 mm (range, 32 to 74 mm). The abnormal leaflet was right coronary leaflet in 16 patients and noncoronary leaflet in 5 patients. The indication for operation was moderate to severe or severe AI. All patients were symptomatic.
Methods
Patients underwent standard cardiopulmonary bypass with ascending aortic and bicaval venous cannulation. Moderate hypothermia with core cooling to 25°C to 28°C, and a left ventricular vent were used. Myocardial protection consisted of topical hypothermia and hyperkalemic cardioplegic arrest. The cardioplegic solution was infused directly into the coronary ostia after the aortic root was opened. Repeated doses of cardioplegia were given at 30-minute intervals throughout the operation if required. The valve was inspected after completion of initial cardioplegic dose. The preoperative echocardiographic criteria for pericardial leaflert replacement was the presence of a single leaflet prolapse. This method was used if there were two normal aortic valve leaflets and a single abnormal leaflet during intraoperative inspection. In all 21 patients, the aortic valve had the characteristic appearance of right coronary leaflet or noncoronary leaflet prolapse or retraction, and the two opposing leaflets were normal. The lengths of the corresponding free edges of the other two leaflets were measured as far as the distance between the nodulus of Aranti and the commissure. The pathologic leaflet was resected. The bovine pericardial patch was cut as shown (Figs 1, 2, and 3).
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Fig 1. Drawing of aortic valve leaflet. D = the nodulus of Arantii; A, B, E = the commissure of aortic valve; C = midpoint of one normal coronary annulus.
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Fig 2. Drawing of the bovine pericardium. DA = da, DB = db, DC = dc. Margin a-c-b was running sutured to the abnormal coronary annulus.
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Fig 3. The bovine pericardium is cut during operation; a-c-b was running sutured to the abnormal coronary annulus.
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For the pathologic right coronary leaflet, the free edge of the bovine leaflet equaled the sum of the length from the commissure between the right coronary cusp and left coronary cusp to the nodule of Aaranti on the corresponding left coronary cusp plus the length of the commissure between the right coronary cusp and noncoronary cusp to the nodule of Aaranti on the corresponding noncoronary cusp. The height of the pericardial leaflet was the length from the nodulus of Arantii to the base of the noncoronary cusp annulus. The annular margin of the pericardial leaflet was running sutured to the right coronary annulus using 5-0 polypropylene (Prolene 5-0; Ethicon, Sommerville, New Jersey). The suture was tied on the outside of the ascending aorta over a Teflon pledget (Impra, subsidiary of L.R. Bard, Tempe, Arizona). Before closing the incision, aortic root leaflet coaptation was evaluated for adequate leaflet coaptation. After closure of the aortic root, the pressure generated during the final infusion of warm blood antegrade cardioplegia at the calculated physiologic coronary flow rates provided a reasonable estimate of valve competency before removal of the aortic crossclamp. After separation from cardiopulmonary bypass, intraoperative transesophageal echocardiography was used to determine competence of the repaired valve.
Concomitant procedures included VSD repair with Dacron patch (C.R. Bard, Haverhill, Pennsylvania) in 17 patients and patch repair of a rupture of the right sinus of Valsalva in 1 before repairing the aortic valve. Patients were not given anticoagulation therapy after operation.
All 21 patients were followed up by two-dimensional echocardiography with Doppler studies, and aortic regurgitation was assessed. Follow-up echocardiography data were collected.
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Results
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There was no mortality or morbidity associated with the operation. Mean cardiopulmonary bypass time was 109.7 ± 27.1 minutes (range, 62 to 165), and mean aortic cross-clamp time was 71.4 ± 20.7 minutes (range, 38 to 110).
The mean postoperative left ventricular end-diastolic diameter was 48 ± 6.5 mm (range, 37 to 59 mm). The postoperative end-diastolic diameter decreased significantly (p < 0.05). The mean postoperative left ventricular end-systolic diameter was 31 ± 5.8 mm (range, 21 to 40 mm). The postoperative end- systolic diameter decreased significantly (p < 0.05). Intraoperative echocardiography demonstrated successful repair with normal coaptation of the leaflet in all patients. The patients were discharged from hospital within 12 days and remained symptom-free at follow-up. Transthoracic echocardiography at the time of hospital discharge showed a significant reduction of AI, and the results were statistically significant (p < 0.05). Thirteen patients had complete relief of aortic insufficiency and 8 had mild residual aortic insufficiency.
The patients were followed up for 6 to 21 months. There was no mortality on follow-up. Transthoracic echocardiography at the last follow-up visit showed 13 patients had no AI, 7 had mild residual AI, and 1 had moderate AI not requiring reoperation.
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Comment
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Successful aortic valve repair requires an understanding of the anatomy and pathology of the aortic root. The ideal substitute for the aortic valve remains elusive despite progress and improvements in mechanical and bioprosthetic valves, allograft biology, and the Ross pulmonary autograft. There are issues with biologic constraints of body growth and calcium metabolism along with prosthesis-patient mismatch. The limitations of synthetic valve substitutes are manifest by complications such as bleeding and thromboembolic events. Therefore, the long-term durability of such options for young patients is debatable. Despite the durability of a mechanical prosthesis, it is desirable to avoid warfarin in all patients, especially in females of childbearing age or athletic males.
Aortic valve repair is slowly evolving. The pulmonary autograft is an attractive alternative, but long-term follow-up has shown inherent structural wall abnormalities in the pulmonary trunk, predisposing to neoaortic dilation and an increased rate of autograft failure [5]. Disappointed by these options, some groups have started to revisit aortic valve repair. Suspending the commissure of the valve and folding the middle of the leaflet are conventional techniques; however, the results have not been encouraging. Pathologic changes are localized to one leaflet with normal two opposing leaflets, which is the norm in AI associated with VSD. The key to treatment is to correct the pathologic leaflet.
Bovine pericardium calcification is a cause for concern. The bovine pericardium used in these patients is also used to manufacture bovine pericardial bioprostheses, which have been found to be free of calcification for approximately 10 years. We hope that the implanted pericardial leaflet would also be free of calcification for at least 10 years. The bovine pericardium was not molded during operation, and it was flat before it was sewn to the aortic annulus, and that may be a potential limitation of this procedure, but the short-term to midterm function of this reconstructed valve has been good. The quality of the bovine pericardium will determine the freedom from reoperation over the long term.
These patients have been followed up for up 6 to 21 months, and none has any aortic stenosis at this point. Long-term follow-up is important to determine whether this technique is promising and durable.
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Acknowledgments
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The authors are thankful to Beijing Balance Bio-Engineering Co, Ltd, who provides the bovine pericardium.
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References
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- Laudito A, Brook MM, Suleman S, et al. The Ross procedure in children and young adults: a word of caution J Thorac Cardiovasc Surg 2001;122:147-153.[Abstract/Free Full Text]
- Pessotto R, Wells WJ, Baker CJ, Luna C, Starnes VA. Midterm results of the Ross procedure Ann Thorac Surg 2001;71(Suppl):336-339.
- Al-Halees Z, Pieters F, Qadoura F, Shahid M, Al-Amri M, Al-Fadley F. The Ross procedure is the procedure of choice for congenital aortic valve disease J Thorac Cardiovasc Surg 2002;123:437-442.[Abstract/Free Full Text]
- Odim J, Laks H, Allada V, Child J, Wilson S, Gjertson D. Results of aortic valve-sparing and restoration with autologous pericardial leaflet extensions in congenital heart disease Ann Thorac Surg 2005;80:647-654.[Abstract/Free Full Text]
- Niwa K, Perloff JK, Bhuta SM, et al. Structural abnormalities of great arterial walls in congenital heart disease: light and electron microscopic analyses Circulation 2001;103:393-400.[Abstract/Free Full Text]
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Abstract
Introduction
