A New Technique for Aortic Valve Dysfunction: Reconstruction
作者：分会办公室来源：中华医学会胸心血管外科学分会
点击:1365次时间:2008-11-14 15:19:17
点击:1365次时间:2008-11-14 15:19:17
Reconstruction by Posterior Leaflet of Tricuspid Valve
Hansong Sun, MD, Qiang Wang, MD, Shengshou Hu, MD, Yinglong Liu, MD, Liqing Wang, MD, and Ge Gao, MD
Department of Surgery, Fuwai Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College, Beijing, China
Valve repair for aortic dysfunction may provide an alternative approach to aortic valve replacement in selected patients. This repair by using posterior leaflet of tricuspid valve could be either an attempt at permanent correction, or palliative to avoid the use of anticoagulation and improve the anticalcification and durability of the implanted cusp. Two patients with aortic valve dysfunction underwent valve repair by this technique. The procedure included tricuspid valvuloplasty and posterior leaflet preparation, reconstruction of the aortic sinus, and posterior leaflet reimplantation to the new aortic sinus. There were no hospital deaths or other valve-relatedcomplication in either patient. Both patients had no tricuspid valve stenosis or regurgitation. Echocardiography in the first patient showed no aortic regurgitation and transvaluvular gradient of 23mmHg, and mild aortic insufficiency and no stenosis in the second patient. Shortterm follow-up (6 months) showed no recurrent aortic dysfunction in either patient. This technique has provided satisfactory early results and could be considered an interesting corrective or palliative surgical approach.
(Ann Thorac Surg 2004;78:348 –51)
© 2004 by The Society of Thoracic Surgeons
Aortic valve dysfunction is usually caused by congenital, rheumatic, degenerative, or other diseases. In adults, development of symptoms with moderate and severe aortic stenosis or insufficiency is an indication for aortic valve replacement. Currently, mechanical and bioprosthetic aortic valve replacement still have some problems, including thromboembolism, infection, and other complications. In view of these problems, we used the posterior leaflet of tricuspid valve to repair aortic valve dysfunction in two cases.
Patients and Methods
Case Report 1
A 35-year-old woman sought treatment for fatigue and exertional angina. Examination revealed precordial systolic and diastolic murmurs. Electrocardiography showed left ventricular hypertrophy. Transesophageal echocardiography (TEE) showed a dilated left ventricle (enddiastolic dimension 58 cm), abnormal congenital aortic bicuspid valve with moderate commissural fusion, and mild regurgitation. Doppler gradient was 60 mm Hg.
Case Report 2
A 36-year-old man was admitted because of progressive exertional dyspnea and paroxysmal the sternum with radiation to the apex. Chest x-ray documented left ventricular enlargement. Electrocardiography showed left ventricular enlargment. TEE showed a dilated left ventricle (end-diastolic dimension 70 cm), abnormal congenital aortic bicuspid valve, the ostia of both coronary arteries within a single sinus of Valsalva, and the corresponding leaflet prolapse with severe regurgitation.
Technique
Both patients knew the details of the new technique before surgical correction and consented to this operation.
The Posterior Leaflet Preparation and Tricuspid
Valvuloplasty
Before resection of the posterior leaflet, the diameter of the tricuspid annulus, not including the portion of the posterior leaflet, was measured to avoid inadequate size after operation. The posterior leaflet was exposed, carefully resected, and placed on gauze surface. The chordal attachments were carefully excised. Four traction sutures were made on the edge of the posterior leaflet to prepare for aortic valve reconstruction. The procedure for tricuspid annuloplasty and the treatment of the deficient area of the tricuspid leaflet are similar to the technique for mitral valvuloplasty by quadrilateral resection of the involved leaflet segment with reapproximation of the annulus and leaflet. The procedure was performed with a pledgetted suture and the leaflets were reattached using 5-0 suture (Fig 1).
Fig 1. Surgical technique used to obtain the posterior leaflet of tricuspid valve and tricuspid valvuloplasty. (a) The posterior leaflet will be excised. (b) Annuloplasty is performed with a pledgetted suture and the leaflets are reapproximated using 5-0 suture.
Reconstruction
In the first patient, who suffered primarily from aortic stenosis, the commissurotomy was made principally in the fused posterior commissure, extending the opening to the annulus. The calcified deposits at this point were also completely de´ brided. The incisions on the two cusps were made, along with the base of the cusps, beginning at the posterior commissure to the midpoint of the base
of the corresponding cusp. The free segments of the cusps were sutured at the inward position of the corresponding sinus with a running suture technique using 5-0 polypropylene suture, so the “new sinus” was established between two cusps. After “new sinus” accomplishment, the previously harvested posterior leaflet was tailored according to the height and the length of the “new sinus.” 5-0 polypropylene sutures were started at the midpoint of the base of the cusp. At the commissure the sutures were extended along the aortic wall corresponding to the height of the “new sinus” to ensure the proper coaptation of the reconstructed valve with other native cusps (Fig 2). In addition, because the ventricular aspect of the posterior leaflet has abundant elastic fibers, we placed it while seeing the aortic aspect to resist the highest pressure.
Fig 2. Surgical technique used to reconstruct a “new” aortic noncoronary leaflet and sinus of Valsalva. (a) Morphologic feature in the first patient with aortic bicuspid valve and moderate commissural fusion. Broken lines show the new corresponding positions of both cusps. (b) New cusp is sutured between commissure A and B with 5-0 polypropylene suture.
In the second patient with aortic regurgitation, because of the severe prolapse of the coronary leaflet, its free edge length was longer than that of the other leaflet. An incision was made on this cusp, beginning one quarter along the length of the free edge from the anterior commissure, extending inferior to the base of the leaflet (Fig 3). An approach similar to that in the first patient was used for the cusp of the remaining three-quarters length, establishing a new “left-coronary leaflet.” The remnants of the right coronary cusp were attached with prepared posterior leaflet with a running suture technique using 7-0 polypropylene sutures. The base of the new cusp of the posterior leaflet was sutured to the aortic wall and a new “right coronary leaflet” was reconstructed (Fig 4).
Fig 3. Surgical technique used to establish “new” left and right coronary leaflets. (a) Incision is made on the bigger cusp, beginning at the point AA’ of the one-quarter length of the free edge from the anterior commissure, extending inferiorly to the point CC’ at the base of the leaflet and continuing to the point D. (b) The incised free edge (A’-C’-D) is refixed to aortic wall forming a new aorta annula (D’C’-BA_). The new commissure “point BA’” is composed of point B and A’ incised from AA’. (C) The deficient area of the right coronary leaflet is treated with the posterior leaflet of tricuspid valve.
Fig 4. Surgical technique used to reconstruct “new” left and right coronary leaflets. (a) Morphologic feature in the second patient with aortic bicuspid valve and severe corresponding leaflet prolapse. Brokenlines (D-B) show the new corresponding position of “new” left coronary leaflet. (b) “New” left and right coronary leaflets are reconstructed using the posterior leaflet of tricuspid valve. “!” (The area composed with A-C-A’B) represents the material of the posterior leaflet. The new commissure “point A’B” is composed of point B and A’ incised from AA’.
Results
No hospital deaths or other valve-related complications occurred in either patient. The immediate postoperative TEE showed no aortic regurgitation and transvalvular gradient of 23 mm Hg in the first patient. The patient was extubated 11 hours after operation and discharged 8 days later.
The second patient was also examined by TEE during operation, with adequate function of the reconstructed aortic valve. Echocardiography before discharge showed mild aortic insufficiency and no stenosis, with a left ventricular end-diastolic dimension of 61 mm. Both patients had no tricuspid valve stenosis or regurgitation at discharge.
Symptoms in both patients were significantly ameliorated 6 months after surgery. Neither patient had recurrent aortic dysfunction. There were no thromboembolic, bleeding, or other complications. In the first patient with aortic stenosis, echocardiography showed the diameter of dilated left ventricle reduced (end-diastolic dimension 51 cm), no aortic regurgitation, and transvalvular gradient of 20 mm Hg. The second patient, with severe aortic leaflet prolapse, had mild aortic regurgitation. The left ventricular end-diastolic dimension of this patient was 57mm. The function of tricuspid valve in both patients was normal at 6-month follow-up.
Comment
The surgical treatment of aortic valve dysfunction remains a clinical problem in selected patients. In these patients, anticoagulation is unavailable or patients may require reoperation because of growth in the young, dysfunction of the implanted bioprosthetic valve, or other reasons. Currently, the valve repair procedure is still being adopted by surgeons, and may provide an alternative to aortic valve replacement. Haydar and associates [1] reported satisfactory intermediate-term results in 44 patients with aortic insufficiency who underwent valve repair. More recently, Grinda[2] reported an autologous pericardium triple-cusp extension technique in young foreign patients with rheumatic aortic insufficiency. The initial and intermediate results of this technique were encouraging. Based on these techniques, we designed a new technique using the posterior leaflet of tricuspid valve to repair aortic valve dysfunction.
Although some morphologic aspects of semilunar and atrioventricular valves are different, the leaflet components of the semilunar and atrioventricular valves are similar. These components include collagen, elastin, and glycosaminoglycans. They form the three principal layers of the leaflets: the fibrosa (arterial or ventricularis), spongiosa, and ventricularis (or atrial). Similar to the aortic valve, the endothelium-lined cusps of the tricuspid valve have a dense collagenous core adjacent to the surface that withstands the highest pressure. The atrial aspect of the tricuspid leaflets and the ventricular aspect of the aortic valves both have abundant elastic fibers [3]. Because of the similarities between tricuspid valve and aortic valve, the tricuspid valve is potential material for diseased aortic valve replacement. Moreover, normal valve leaflets and cusps are avascular [4]. Since the needed nutrition of valves may come directly from blood passing through the heart, the free cusp of tricuspid valve reimplanted to the aortic sinus can survive, and in theory resists calcification better and is more durable than glutaraldehyde-treated pericardium.
To determine whether aortic insufficiency in a given patient can be repaired by this technique, we observe and evaluate the extent of diseased aortic cusp after the aortic wall is incised. Some aspects must be considered in this technique. The first is that the aortic cusps have no severe calcification. Second, because the posterior leaflet is small, no more than two diseased leaflets must be involved. For example, a 34-year-old human with severe aortic insufficiency underwent aortic repair by this technique in our hospital. The free edge of three cusps showed degenerative calcification and limited motion. We extended the free edge of the right coronary cusp and non-coronary cusp using the posterior leaflet of the tricuspid, but had no material to extend the left coronary cusp. We found the moderate aortic insufficiency by TEE after removing the cross-clamp. This patient underwent aortic valve replacement and recovered on the 8th day after the operation. Other considerations include a normal tricuspid valve and adequate annulus. We usually measure the size of the annulus composed of anterior and septal leaflet to evaluate whether the residual area of tricuspid valve is adequate.
The height and base of the reconstructed aortic leaflet were based on normal aortic leaflet structure that the length of its base be approximately 1.5 times longer than the length of the its free margin. The height of the aortic sinus corresponds to 60% to 70% of the diameter of the aortic annulus [5–7].
The benefits of this technique are preservation of the aortic valve leaflet, the ability of the annulus and leaflet to grow, and avoidance of anticoagulation. This technique could be used in patients with infectious, degenerative, or mild rheumatic aortic valve disease, especially in young patients with congenital aortic valve dysfunction. Although intermediate results should be studied, this technique has provided satisfactory early results and could be considered as an interesting corrective or palliative surgical approach.
References
1. Haydar HS, He GW, Hovaguimian H, McIrvin DM, King DH,Starr A. Valve repair for aortic insufficiency: surgical classification and techniques. Eur J Cardiothorac Surg 1997;11:258–
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2. Grinda JM, Latremouille C, Berrebi AJ, et al. Aortic cusp extension valvuloplasty for rheumatic aortic valve disease: midterm results. Ann Thorac Surg 2002;74:438–43.
3. Gross L, Kugel MA. Topographic anatomy and histology of the valves in the human heart. Am J Pathol 1931;7:445.
4. Schoen FJ, John Sutton MS. Contemporary pathologic considerations in valvular heart disease. In Virmani R, ed. Cardiovascular pathology. Philadelphia: WB.Saunders, 1991:334–53.
5. Kunzelman KS, Grande KJ, David TE, et al. Aortic root and valve relationship: impact on surgical repair. J Thorac Cardiovasc Surg 1994;107:162–70.
6. Silver MA, Roberts WC. Detailed anatomy of the normally functioning aortic valve in hearts of normal and increased weight. Am J Cardiol 1985;55:454–61.
7. Reid K. The anatomy of the sinus of Valsalva. Thorax 1970;25:79–85.
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Accepted for publication June 13, 2003.
Address reprint requests to Dr Qiang Wang, Division of Surgery, Fuwai Hospital, Beilishi Rd 167, Xicheng District, Beijing 100037, China; e-mail: wq.cory@163.com.
© 2004 by The Society of Thoracic Surgeons 0003-4975/04/$30.00
Published by Elsevier Inc doi:10.1016/S0003-4975(03)01283-9
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