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Ann Thorac Surg 2002;74:S1769-S1772
© 2002 The Society of Thoracic Surgeons
a department of Cardiothoracic Surgery, Mount Sinai Medical Center, New York, New York, USA
b Biomathematical Sciences, Mount Sinai Medical Center, New York, New York, USA
c Department of Englewood Cardiac Center, Englewood Hospital, Englewood, New Jersey, USA
* Address reprint requests to Dr Galla, Department of Cardiothoracic Surgery, Box 1028, Mount Sinai Medical Center, New York, NY, 10029, USA.
e-mail: jan.galla{at}mssm.edu
Presented at the Aortic Surgery Symposium VIII, May 2–3, 2002, New York, NY.
Abstract
BACKGROUND: Patients requiring aortic root reconstruction who are deemed unable to take anticoagulants offer unique challenges to the surgeon. For these patients, we have been manufacturing composite conduits intraoperatively using stented bioprostheses.
METHODS: During the 10-year period from April 1992 until May 2002, 141 patients (105 male, 36 female) from 34 to 88 years of age underwent aortic root reconstruction with biological valved conduits. Diagnoses included dissection (n = 28, 9 acute type A), degenerative (64), atherosclerotic (32), anuloaortic ectasia (9), endocarditis (5), and other causes (3). Preoperative risk factors included hypertension (90), smoking (63), coronary artery disease (48), and diabetes (6). Valved conduits were mainly constructed from pericardial valves and impregnated Dacron grafts. Distal anastomosis was performed open in all cases except 6; the ascending aorta only was replaced in 63 patients, a hemiarch reconstruction was used in 71, and more extensive arch reconstruction in 7. Additional cardiac procedures were performed in 59 patients.
RESULTS: Two deaths occurred in the operating room (biventricular failure). Late hospital mortality was 11 of 141 (7.8%) of which 6 (55%) were cardiac, 2 (18.2%) were infectious, 2 (18.2%) were of other complications and 1 (9.1%) was unknown. Three patients (2.1%) sustained permanent and 3 transient strokes. No structural deterioration of the valve and an approximately 86% freedom from thromboembolic events was observed during 5 years.
CONCLUSIONS: For patients for whom anticoagulation is contraindicated or undesirable, reconstruction of the aortic root with a stented bioprosthetic valved conduit offers an acceptable alternative to mechanical prostheses.
The development by Bentall and DeBono [1] of a reliable, reproducible technique for reconstruction of the aortic root has resulted in the routine repair of complex aortic root pathologies. Modifications of the original Bentall repair by Kouchoukos and associates [2] and Cabrol and coworkers [3] have found considerable application in difficult root reconstructions. In addition to the use of a valved conduit, many other alternatives to aortic root reconstruction have been developed, including valve preservation techniques [4], use of homografts [5], pulmonary autografts [6], or stentless aortic valves [7]. Each of these techniques has advantages as well as disadvantages; the homograft, stentless valve, and valve preservation methods have steep learning curves. Homografts may not be readily available. The valved conduit techniques of Bentall and DeBono [1], Kouchoukos and associates [2], and Cabrol and colleagues [3] are all generally performed with commercially available mechanical valved conduits and require lifetime anticoagu-lation. For those patients unable unwilling or too unreliable to maintain adequate anticoagulation the use of a biological prosthesis is desirable. It is precisely these patients in whom we have been using an intraoperatively manufactured biological valved conduit and we now present our methods and results gathered over a 10-year period.
Patients and methods
Patients
One hundred forty-one patients (105 male, 36 female) with an average age of 69.5 years (range 32 to 88), underwent aortic root replacement with a biological valved conduit from April 1992 through May 2002. Aortic pathologies included degenerative (64), atherosclerotic (32), dissection (28) of which 9 were acute, anuloaortic ectasia (9), endocarditis (5) and other (3). Preoperative risk factors were commensurate with the age group of the patients: there were 90 patients with hypertension; 63 were smokers; coronary artery disease was present in 48 and diabetes mellitus in 6. Twenty-seven patients were undergoing reoperation. The extent of aortic resection included ascending aorta (63), hemiarch (71) total arch (7) including 5 stage I elephant trunks, and 1 distal arch. Associated coronary revascularization was performed in 49 patients and other valve procedures in 9. Ascending aortic size varied from 3.5 to 12 cm. Evidence of contained rupture was present in 9 patients but no patient had free blood in the pericardium. In 5 of the 8 acute dissections the coronary arteries were involved and required repair.
Methods
A median sternotomy was used in 138 patients, and a thoracosternotomy in 3. Standard cardiopulmonary bypass techniques were supplemented with antegrade (24 patients), retrograde (5 patients), or selective cerebral perfusions (6 patients); moderate to profound hypothermia was used in all cases. Hypothermic circulatory arrest was used in all but 4 patients and an open distal anastomosis was routinely performed
Conduits were manufactured by selecting an appropriate size valve prosthesis and suturing a conduit to it with a running 4-0 polypropylene suture (Fig 1), yielding a readily usable unit (Fig 2). Pericardial valves (Edwards Lifesciences LLC, Irvine, CA) were used in 122 patients and porcine valves in the remaining 20; sizes ranged from 19 to 31 mm. All but two grafts were collagen coated (Hemashield; Meadox Medicals, Oakland, NJ), from 24 to 36 mm diameters. Aortic root reconstruction was then undertaken as previously described [8]. Care was taken that all interrupted annular sutures engaged both the valvular sewing ring and the vascular graft.
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Results
There were 2 (1.4%) intraoperative deaths, both the result of biventricular failure. Both of these patients’ aortic roots were being reconstructed for pathology resulting from endocarditis; postmortem examination in 1 revealed extensive involvement of intracardiac structures with Aspergillus organisms.
Nine patients (6.4%) died in the hospital of other causes. Cardiac failure caused 6 (4.3%)deaths; 2 patients (1.4%) died of multiorgan system failure, and 1 (0.7%) of infection.
Five patients (3.5%) were reexplored for bleeding. Thirty-five patients had prolonged ventilatory support; 12 (8.4%) required tracheostomy. Cardiac complications were seen in 26 patients, including supraventricular tachycardia (12 patients), ventricular failure (4 patients), ventricular fibrillation (3 patients), complete heart block necessitating pacemaker implantation (3 patients), delayed tamponade requiring drainage (3 patients), and electromechanical dissociation (1 patient). Postoperative renal dysfunction was experienced by 6 patients, 2 of whom ultimately became dialysis-dependent. There were 9 postoperative infections, 6 involving the sternotomy incision: 3 (2.1%) required mediastinal exploration and debridement.
Cerebrovascular accidents (CVAs) were seen early in 6 patients (4.2%). Three (2.1%) were early and permanent, and 3 were transient with all symptoms resolving before discharge but with brain involvement confirmed by computed tomography. Transient neurologic dysfunction was seen in 40 (28.2%) of the patients.
Late (postdischarge) deaths were identified in 21 (14.9%) of the overall population. Infection and neoplasia each account for the majority of these deaths over the 10-year period (5 patients each; 3.5%). Four patients died of cardiac problems (2.8%), 3 patients died of gastrointestinal problems unrelated to carcinoma (2.1%), and 4 deaths (2.8%) arose from a variety of miscellaneous causes. One patient died of suspected rupture of the aorta but the cause of death could not be confirmed. Overall survival at 5 years was approximately 60%, compared with an expected survival of 80% (Fig 3).
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For the patient requiring aortic root reconstruction, many options are available and the procedure can be tailored for each individual. The most commonly used alternative is the Bentall repair, usually performed as the Kouchoukos [2] or Cabrol [3] modification. Use of a commercially available valved conduit mandates lifelong anticoagulation for the patient as no tissue-valved conduits are commercially available in the United States. For those patients unable, unwilling, or too unreliable to take anticoagulants, however, each of the commonly cited alternatives to the Bentall procedure has significant limitations, primarily the need for extensive experience in order to obtain satisfactory results. Seemingly minor adjustments, easily forgotten from case to case, may change an optimal repair to a completely unsalvageable result. Additionally, trepidation over unfamiliar techniques involving use of homografts or stentless aortic valves coupled with fears of liability may cause surgeons to favor the more familiar—but perhaps less desirable—mechanical valved conduit in cases where anticoagulation is not absolutely contraindicated. The familiarity of a bioprosthesis coupled with its reproducible correction of aortic valve pathology makes the use of a bioprosthetic valved conduit a favorable option.
The durability of the manufactured bioprostheses, especially the pericardial valve, is well documented [9]. When used as a component of a valved conduit in an appropriately aged population, one would expect a lifelong repair from this device. The life expectancy in the present cohort did not exceed the demonstrated durability of the pericardial valve, rendering this an acceptable choice for aortic root reconstruction, with the expectation of an anticoagulation-free life. For younger patients unable or unwilling to take anticoagulants, the use of the fabricated pericardial-valved conduit should allow 10 to 15 years of freedom from anticoagulation before requiring valve replacement. In our small experience of replacing biological valves within a conduit (Ionescu-Shiley valves implanted before this series), we have found these operations to be straightforward.
The absence of a commercially available device in the United States requires fabrication of the valved conduit at the time of surgery, potentially lengthening both the cross clamp and pump times. We have found, however, that by judiciously sequencing the steps in constructionof the conduit we have only added 3 to 4 minutes to the operative procedure. The rapidity with which an appropriately sized valved conduit can be constructed allows the use of this device in a wide range of pathologies, as described in the current series. Extensive aortic reconstructions including total and hemi arch replacements are easily performed without alteration in surgical routines. Coronary revascularization and other valvular procedures are also readily performed when implanting this conduit. When appropriately thorough debridement has been performed curative repairs for endocarditic pathology may also be anticipated, as evidenced by the results presented herein in which the surviving patients operated on for endocarditis have remained free from reinfection subsequent to their operations.
The use of the biological valved conduit should be considered a surgical option for treating those patients for whom anticoagulation is not desirable, particularly if appropriate alternatives are unavailable or are unfamiliar to the surgeon. Our data indicate that acceptable results comparable to other techniques of repair or reconstruction are to be expected despite the (usually) advanced age of the patients.
References
This article has been cited by other articles:
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  M. E.W. Kirsch, T. Ooka, K. Zannis, J.-F. Deux, and D. Y. Loisance Bioprosthetic replacement of the ascending thoracic aorta: what are the options? Eur. J. Cardiothorac. Surg., January 1, 2009; 35(1): 77 - 82. [Abstract] [Full Text] [PDF]
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 T. Tsunekawa, H. Ogino, H. Matsuda, K. Minatoya, H. Sasaki, J. Kobayashi, T. Yagihara, and S. Kitamura Composite Valve Graft Replacement of the Aortic Root: Twenty-Seven Years of Experience at One Japanese Center Ann. Thorac. Surg., November 1, 2008; 86(5): 1510 - 1517. [Abstract] [Full Text] [PDF]
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K. K.W. Lau, K. Bochenek-Klimczyk, M. Galinanes, and A. W. Sosnowski Replacement of the Ascending Aorta, Aortic Root, and Valve with a Novel Stentless Valved Conduit Ann. Thorac. Surg., July 1, 2008; 86(1): 278 - 281. [Abstract] [Full Text] [PDF]
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G. Gatti, B. Benussi, A. Pappalardo, and B. Zingone Aortic root replacement with a valved conduit containing a stented xenograft Eur. J. Cardiothorac. Surg., April 1, 2008; 33(4): 740 - 741. [Abstract] [Full Text] [PDF]
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