ATS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Ad J. J. C. Bogers
Johanna J.M. Takkenberg
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bogers, A. J. J. C.
Right arrow Articles by Takkenberg, J. J.M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bogers, A. J. J. C.
Right arrow Articles by Takkenberg, J. J.M.
Related Collections
Right arrow Valve disease

Ann Thorac Surg 2004;77:1998-2003
© 2004 The Society of Thoracic Surgeons

Original article: cardiovascular

Is a bicuspid aortic valve a risk factor for adverse outcome after an autograft procedure?

Ad J. J. C. Bogers, MD, PhDa*, Arie-Pieter Kappetein, MD, PhDa, Jolien W. Roos-Hesselink, MDb, Johanna J.M. Takkenberg, MD, PhDa

a Cardiothoracic Surgery, Rotterdam, The Netherlands
b Cardiology, Thoraxcentre, Erasmus MC, Rotterdam, The Netherlands

Accepted for publication December 2, 2003.

* Address reprint requests to Dr Bogers, Department of Cardiothoracic Surgery, Thoraxcentre, Bd 158, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands
e-mail: a.j.j.c.bogers{at}erasmusmc.nl


   Abstract
Top
 Abstract
Introduction
 Material and methods
 Results
 Comment
 References
 
BACKGROUND: Recently, bicuspid aortic valve disease is posed to be a possible risk factor for dilatation of the pulmonary autograft.

METHODS: Analysis of all 123 patients in our prospective cohort with their native aortic valve in situ at the autograft procedure.

RESULTS: The bicuspid aortic valve group (n = 81) had more males (p = 0.05), prior cardiac surgery (p = 0.02), prior aortic valve balloon dilatation (p = 0.01), aortic stenosis (p = 0.03), and less deterioration of left ventricular function (p = 0.02) than the tricuspid group (n = 42). Hospital mortality occurred in 3 patients (bicuspid 2, tricuspid 1). The follow-up was 99% complete (median, 5.3 years; SD, 3.5; range, 0.1 to 13.4) with a total of 674 patient years. During follow-up 4 patients died (bicuspid 2, tricuspid 2). Overall survival was 95% (95% confidence interval [CI], 89% to 98%) at 5 and 10 years. Seven patients required reoperation for autograft failure, all structural. Freedom from autograft reintervention was 97% (95% CI, 92% to 100%) at 5 years and 89% (95% CI, 79% to 98%) at 10 years. There were no differences in outcome between the groups. Four patients required reoperation for allograft failure, all structural. Freedom from allograft reoperation was 99% (95% CI, 97% to 100%) at 5 years and 91% (95% CI, 82% to 100%) at 10 years. There was no difference between the groups.

CONCLUSIONS: An autograft procedure in patients with a bicuspid aortic valve is justified. Bicuspid aortic valve disease is not a contraindication for an autograft procedure. Patients with a bicuspid aortic valve will meet the limitations of the autograft procedure in the same frequency as the overall autograft population.


   Introduction
Top
 Abstract
 Introduction
Material and methods
 Results
 Comment
 References
 
Recently, the issue arose over whether or not a bicuspid aortic valve is a risk factor for adverse outcome after an autograft procedure [1–5]. The presence of a bicuspid aortic valve is associated with aortic dilatation, aneurysm formation, and aortic dissection due to focal abnormalities within the aortic media. Although the aortic and pulmonary arterial walls do differ histologically in the normal situation [6, 7], the pulmonary artery has the same embryologic origin as the aorta and undergoes similar degenerative changes. Knowing that the aortic wall is abnormal in patients with a bicuspid aortic valve [5, 8–10], the causative mechanism for autograft failure was suggested to be an abnormality of the pulmonary arterial as well [4, 5]. It is not yet clear, however, whether these differences in patients with a bicuspid aortic valve effectively predispose to clinical autograft failure [5]. This would create a significant problem because in most autograft series, patients with a bicuspid aortic valve mount up to 60% to 70% of the patient population [1, 3, 11]

From the clinical point of view we would expect such a predisposition to cause problems either at the proximal anastomosis, at the autograft itself, or at the distal anastomosis. To assess the outcome after an autograft procedure possible allograft problems should be studied as well. In this regard we analyzed in our series of autograft procedures whether or not a bicuspid aortic valve results in a higher rate of autograft failure.


   Material and methods
Top
 Abstract
 Introduction
 Material and methods
Results
 Comment
 References
 
The present analysis was conducted in accordance with the regulations of the institutional medical ethical committee; the patients consented to being included in our registry. Between September 1988 and June 2002, 134 patients underwent an autograft procedure at our institution. Eleven patients had a previous aortic valve replacement and were excluded from this study, because a history of aortic valve replacement might influence dilatation of the aortic annulus and root.

The remaining 123 patients with their native aortic valve in situ at the autograft procedure were included in the present analysis. Characteristics of patients and operations are presented in Tables 1 and 2. Most of these patients are included in previous reports on different aspects of the autograft procedure [11–13].


View this table:
[in this window]
[in a new window]
  		Table 1. Preoperative Characteristics

 

View this table:
[in this window]
[in a new window]
  		Table 2. Operative Details

 
Left ventricular function was assessed by angiography or echocardiography and graded semiquantitatively as good or mildly, moderately or severely, impaired. Aortic valve morphology was determined using the operative reports. A tricuspid aortic valve, defined as having three separate functional leaflets, was found in 42 patients. A bileaflet aortic valve was defined as having two separate functional leaflets. One of these may contain a more or less developed fusion area or raphe. A unicuspid aortic valve was defined as having one commissure and a single functional leaflet. Because of the low numbers of unicuspid valves, and because the distinction between unicuspid and bicuspid could not always be made accurately, these two valve types are analyzed together and further referred to as the bicuspid group, containing 81 patients. Preoperatively, the aortic annulus was dilated in 2 patients (bicuspid 1, tricuspid 1), the aortic sinuses were dilated in 9 patients (bicuspid 4, tricuspid 5), and the ascending aorta was dilated in 4 patients (bicuspid 3, tricuspid 1).

Concerning the operative technique, the proximal anastomosis of the autograft onto the aortic annulus was done by continuous suturing technique in 98 patients (bicuspid 68, tricuspid 30) and by interrupted sutures in 25 patients (bicuspid 13, tricuspid 12). In all patients the pulmonary valve was replaced by a pulmonary allograft. Valve-related events were scored as defined by previously published guidelines [14]

The 11 patients that were excluded because of previous aortic valve replacement, did not differ in outcome from our study cohort (no mortality, 1 autograft reoperation for structural valve disease at 5.8 years postoperatively, 1 balloon dilatation for stenosis of the pulmonary allograft at 0.7 years postoperatively, and 1 replacement of the pulmonary allograft at 2.1 years postoperatively). During follow-up patients underwent standardized serial echocardiography at 6 months, 1 year, and yearly thereafter to determine autograft and allograft function over time.

All analyses were done using SPSS 10.0 for Windows (SPSS, Chicago, IL). Means were compared using the unpaired t test. The {chi}2 test or Fischer's exact test were used to compare categorical variables. All tests were two sided, with an {alpha} level of 0.05. Cumulative survival and freedom from reintervention or valve-related events were analyzed using the Kaplan-Meier method. The survival of a patient started at the time of the autograft procedure and ended at death (event) or last follow-up (censoring). The analysis of autograft and allograft survival started at the time of autograft procedure and ended at reintervention (event) or last follow-up or patient death (censoring). The log-rank test was used to compare survival between groups.


   Results
Top
 Abstract
 Introduction
 Material and methods
 Results
Comment
 References
 
Patients with a bicuspid aortic valve more often had a history of cardiac surgery (27/81 vs tricuspid 7/42, p = 0.01) as well as prior balloon dilatation of the aortic valve (20/81 vs tricuspid 3/42, p = 0.02). By definition of our study cohort the etiology of the aortic valve disease is different in the two study groups (see Table 1).

The groups differed in the diagnosis posing the indication for surgery. Aortic stenosis, either valvular or subvalvular, and either alone or in combination with aortic regurgitation, was significantly more often the indication for surgery in the bicuspid valve group (65/81 vs tricuspid 22/42, p = 0.002).

At admission for operation, the mean overall weight and length were 58 kg (standard deviation [SD], 24; range, 4 to 111) and 156 cm (SD, 35; range, 48 to 200), respectively. All patients were in sinus rhythm. In 108 patients, data on left ventricular function from echocardiographic or angiographic studies were available. In this subset of patients the left ventricular function was less often deteriorated in the bicuspid valve group (8/70 vs tricuspid 12/38, p = 0.04) (Table 1). In our study group 51 patients were in New York Heart Association class I, 45 in class II, 19 in class III, 5 in class IV and in 3 the class was unknown; there was no difference between the bicuspid and tricuspid valve groups.

The autograft procedure in our center is routinely carried out with the root replacement technique. This yielded 117 root replacement procedures, no subcoronary procedures, and only 6 inlay procedures. The inlay procedures were less often carried out in the bicuspid valve group (1/81 vs tricuspid 5/37, p = 0.02). Concomitant procedures were done in 22 patients, without a difference between the groups. No circulatory arrest was applied.

Three patients died in hospital. In the bicuspid valve group one patient died of postoperative sepsis and mediastinitis and one due to a myocardial infarction after intraoperative damage to a coronary artery. In the tricuspid valve group a Marfan patient with a root aneurysm in preoperative cardiogenic shock died postoperatively due to cardiac failure.

One patient (bicuspid native aortic valve) needed a permanent pacemaker for postoperative total atrioventricular block. No perioperative transient ischemic attacks or strokes of any kind were registered. In the early postoperative period, 16 patients (13%) needed mediastinal reexploration for persisting blood loss.

Follow-up was 99% complete. The mean follow-up was 5.5 years (median, 5.3; SD, 3.5 years; range, 0.1 to 13.4 years) with a total follow-up of 674 patient years. During follow-up another 4 patients died, 2 patients in each group. Postoperatively one patient, discharged in good health but readmitted after 4 weeks for noncardiac infection, died of sepsis after 7 weeks. One patient died due to recurrent rheumatic fever after 6 months, one after 1.8 years due to cardiac failure, and one patient died 4.9 years postoperatively due to cardiac failure after replacement of the autograft with a mechanical prosthesis 4 months earlier. Overall survival at 5 and 10 years was 94% (95% CI, 89% to 98%) (Fig 1). Endocarditis was diagnosed in 2 patients; in 1 patient of the autograft after 3.4 years and in 1 patient of the allograft after 8.8 years. Both were treated medically.



View larger version (7K):
[in this window]
[in a new window]
  		Fig 1. Cumulative survival after autograft procedure for native aortic valve disease.

 
Seven patients required operative reintervention of the autograft, all for structural valve failure. Clinically this consisted of progressive root dilatation with regurgitation of the autograft valve. Macroscopically no signs of degeneration were observed, in particular no stenosis or calcification. Histology of 2 explanted autografts revealed an abrupt focal interruption of the elastin skeleton of the media [15]. In 4 of these patients a mechanical bileaflet aortic valve prosthesis was implanted in the autograft root, 2 patients underwent a prosthetic root replacement, and in 1 patient an allograft root replacement was done. There were no postoperative catheter interventions on the autograft.

Freedom from autograft reintervention was 97% (95% CI, 92% to 100%) at 5 years and 89% (95% CI, 80% to 98%) at 10 years. There were no differences between the 2 groups (Fig 2).



View larger version (12K):
[in this window]
[in a new window]
  		Fig 2. Freedom from autograft reintervention for bicuspid or tricuspid aortic valve disease.

 
In the 116 surviving patients, 493 echocardiographic studies were performed after discharge. Table 3 displays the echocardiographic findings of all 109 patients (excluding death and those patients who were reoperated) at last follow-up. Of this last echocardiographic follow-up, adequate information was available for 106 autografts and 105 allografts.


View this table:
[in this window]
[in a new window]
  		Table 3. Echocardiographic Findings at Last Follow-Up (n = 109, Excluding Death and Reoperation)

 
In 107 patients (including those who were reoperated or who died during follow-up) more than one echocardiographic study with information on autograft regurgitation was available. Figure 3 displays for each patient the linear regression line that reflects the progression of echocardiographic aortic valve regurgitation over time. The bold line represents the overall progression of echocardiographic regurgitation of the whole autograft group over time, which can also be described by the equation: y = 0.84 + 0.114*t.



View larger version (37K):
[in this window]
[in a new window]
  		Fig 3. Progression of echocardiographic autograft regurgitation over time. For each patient the linear regression line that reflects the progression of echocardiographic aortic valve regurgitation over time is presented. The bold line represents the overall progression of echocardiographic regurgitation of the whole autograft group over time, which can also be described as yt = 0.84 + 0.114*t (yr = regurgitation at time t).

 
Four patients required reoperation for allograft failure, all structural. There were no postoperative catheter interventions on the allograft. Freedom from allograft reintervention was 99% (95% CI, 97% to 100%) at 5 years and 91% (95% CI, 82% to 100%) at 10 years (Fig 4). There was no difference between the bicuspid valve and tricuspid valve group.



View larger version (8K):
[in this window]
[in a new window]
  		Fig 4. Freedom from allograft reintervention after autograft procedure for native aortic valve disease.

 
Last echocardiographic follow-up was available for 100 autografts and 99 pulmonary allografts (Table 3). A right ventricular outflow tract gradient of 30 mm Hg or more was found in 15 patients.


   Comment
Top
 Abstract
 Introduction
 Material and methods
 Results
 Comment
References
 
It is well known that the aortic and pulmonary arterial wall differ histologically [5, 6, 9] and that the pulmonary arterial wall changes dynamically during life [7]. In patients with a bicuspid aortic valve the aortic wall is abnormal, with thinner elastic lamellae and a greater distance between the elastic lamellae [8]. The pulmonary arterial wall may show abnormalities in association with bicuspid aortic valve as well [4, 5]. However, there is no conclusive evidence so far that the pulmonary arterial wall in patients with a bicuspid aortic valve additionally predisposes to autograft failure.

Clinical analysis has resulted in a limited number of reports on this subject, in part based on selected patients [1, 2, 4] and in part based on observations other than consecutive cohort series [3]. Nevertheless the advice was put forward to provide additional support for the autograft, in particular at the proximal anastomosis and at the sinotubular junction of the autograft during surgery [1, 2, 5].

In our present consecutive series of patients, those with a bicuspid aortic valve showed some baseline differences compared to the patients with a tricuspid aortic valve. For instance, they had more prior surgery on the aortic valve, had more prior balloon dilatations on the aortic valve, had a lower male to female ratio, had more often aortic stenosis as preoperative diagnosis, and had less often an impaired left ventricular function. The root replacement technique was applied almost exclusively. However, we found no differences in postoperative events between patients with bicuspid and tricuspid aortic valves. Both survival and reoperation rates were satisfactory. Our series does not confirm that a bicuspid aortic valve is a risk factor for failure after an autograft procedure. Consequently, a bicuspid aortic valve is also not an argument for additional surgical measures providing external support of the autograft in this selection of patients. However, the incidence of autograft regurgitation is certainly a clinical problem, already well known from the series by Chambers and colleagues [16] and is, at least in part, related to autograft root dilatation [17]. Serial echocardiography in our series suggests that autograft regurgitation over time is progressive (0.114 grade per year).

In order to provide additional support for the autograft we pay attention to inserting the autograft as close as possible onto the aortic annulus [13, 17]. Further follow-up studies should provide more information on the results of this technique in comparison with different methods of autograft support [1, 5]. The recently described methodology of meta-analysis and microsimulation to assess durability of valve substitutes is very useful in this regard [12, 18].

We conclude that the application of an autograft procedure in patients with a bicuspid aortic valve is justified, that bicuspid aortic valve disease is not a contraindication for an autograft procedure, and that patients with a bicuspid aortic valve will meet the limitations of the autograft procedure in the same frequency as the overall autograft population.


   References
Top
 Abstract
 Introduction
 Material and methods
 Results
 Comment
 References
 

  1. David T.E., Omran A., Ivanov J., et al. Dilatation of the autograft after the Ross procedure. J Thorac Cardiovasc Surg 2000;119:210-220.[Abstract/Free Full Text]
  2. Dossche K.M., Brutel de la Riviee A., Morshuis W.J., Schepens M.A.A.M., Ernst S.M., van den Brand J.J. Aortic root replacement with the pulmonary autograft: an invariably competent aortic valve?. Ann Thorac Surg 1999;68:1302-1307.[Abstract/Free Full Text]
  3. Favalaro R., Stutzbach P., Gomez C., Machain A., Casabe H. Feasability of the Ross procedure: its relationship with the bicuspid aortic valve. J Heart Valve Dis 2002;11:375-382.[Medline]
  4. Fedak P.W.M., Verma S., David T.E., Leask R.L., Weisel R.D., Butany J. Clinical and pathophysiological implications of a bicuspid aortic valve. Circulation 2002;106:900-904.[Free Full Text]
  5. de Sa M., Moshkovitz Y., Butany J., David T.E. Histologic abnormalities of the ascending aorta and the pulmonary trunk in patients with bicuspid aortic valve disease: clinical relevance to the Ross procedure. J Thorac Cardiovasc Surg 1999;118:588-596.[Abstract/Free Full Text]
  6. Hokken R.B., Bartelings M.M., Bogers A.J.J.C., Gittenberger-de Groot A.C. Morphology of the pulmonary and aortic roots with regards to the pulmonary autograft procedure. J Thorac Cardiovasc Surg 1997;113:453-461.[Abstract/Free Full Text]
  7. Saldana M., Arias-Stella J. Studies on the structure of the pulmonary trunk; 1. Normal changes in the elastic configuration of the human pulmonary trunk at different ages. Circulation 1968;27:1086-1093.
  8. Bauer M., Pasic M., Meyer R., et al. Morphometric analysis of aortic media in patients with bicuspid and tricuspid aortic valve. Ann Thor Surg 2002;74:58-62.[Abstract/Free Full Text]
  9. Schmidt F.X., Bielenberg K., Schneider A., Haussler A., Keyser A., Birnbaum D. Ascending aortic aneurysm associated with bicuspid and tricuspid aortic valve: involvement and clinical relevance of smooth muscle cell apoptosis and expression of cell death-initiating proteins. Eur J Cardiothor Surg 2003;23:537-543.[Abstract/Free Full Text]
  10. Ward C. Clinical significance of the bicuspid aortic valve. Heart 2000;83:81-85.[Free Full Text]
  11. Takkenberg J.J.M., Dossche K.M.E., Hazekamp M.G., Jansen E.W.L., Waterbolk T.W., Bogers A.J.J.C. on behalf of the Dutch Ross Study group. Report of the Dutch experience with the Ross procedure in 343 patients. Eur J Cardiothor Surg 2002;22:70-77.[Abstract/Free Full Text]
  12. Takkenberg J.J.M., Eijkemans M.J.C., van Herwerden L.A., et al. Estimated event-free life expectancy after autograft aortic root replacement in adults. Ann Thorac Surg 2001;71:S344-348.[Abstract/Free Full Text]
  13. Hokken R.B., Bogers A.J.J.C., Taams M.A., et al. Aortic root replacement with a pulmonary autograft. Eur J Cardiothor Surg 1995;9:378-383.[Abstract]
  14. Edmunds L.H., Jr, Clark R.E., Cohn L.H., Grunkemeier G.L., Miller D.C., Weisel R.D. Guidelines for reporting morbidity and mortality after cardiac valvular operations. Eur J Cardiothor Surg 1996;10:812-816.[Abstract]
  15. Takkenberg J.J.M., Zondervan P.E., van Herwerden L.A. Progressive pulmonary autograft root dilatation and failure after Ross procedure. Ann Thorac Surg 1999;67:551-554.[Abstract/Free Full Text]
  16. Chambers J.C., Somerville J., Stone S., Ross D.N. Pulmonary autograft procedure for valve disease: long term results of the pioneer series. Circulation 1997;96:2206-2214.[Abstract/Free Full Text]
  17. Hokken R.B., Takkenberg J.J.M., van Herwerden L.A., Roelandt J.R.T.C., Bogers A.J.J.C. Excessive pulmonary autograft dilatation causes important aortic regurgitation. Heart 2003;89:933-934.[Free Full Text]
  18. Takkenberg J.J.M., Puvimanasinghe J.P.A., Grunkemeier G.L. Simulation models to predict outcome after aortic valve replacement. Ann Thorac Surg 2003;75:1372-1376.[Free Full Text]



This article has been cited by other articles:


Home page
 Eur Heart JHome page
L. M.A. Klieverik, J. A. Bekkers, J. W. Roos, M.J.C. Eijkemans, G. B. Raap, Ad. J.J.C. Bogers, and J. J.M. Takkenberg
Autograft or allograft aortic valve replacement in young adult patients with congenital aortic valve disease
Eur. Heart J., June 1, 2008; 29(11): 1446 - 1453.
[Abstract] [Full Text] [PDF]

Home page
 J. Thorac. Cardiovasc. Surg.Home page
P. H. Schoof, J. J.M. Takkenberg, R.-J. van Suylen, P. E. Zondervan, M. G. Hazekamp, R. A.E. Dion, and A. J.J.C. Bogers
Degeneration of the pulmonary autograft: An explant study
J. Thorac. Cardiovasc. Surg., December 1, 2006; 132(6): 1426 - 1432.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
J. J.M. Takkenberg, A. P. Kappetein, L. A. van Herwerden, M. Witsenburg, L. V. Osch-Gevers, and A. J.J.C. Bogers
Pediatric Autograft Aortic Root Replacement: A Prospective Follow-Up Study
Ann. Thorac. Surg., November 1, 2005; 80(5): 1628 - 1633.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Ad J. J. C. Bogers
Johanna J.M. Takkenberg
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bogers, A. J. J. C.
Right arrow Articles by Takkenberg, J. J.M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bogers, A. J. J. C.
Right arrow Articles by Takkenberg, J. J.M.
Related Collections
Right arrow Valve disease

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ANN THORAC SURG ASIAN CARDIOVASC THORAC ANN EUR J CARDIOTHORAC SURG
J THORAC CARDIOVASC SURG ICVTS ALL CTSNet JOURNALS