Asian Annals
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 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):
Raghavendra Vijayanagar
Narendra Sastry
Ira Siegman
Narayana Rattehalli
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vijayanagar, R.
Right arrow Articles by Cortelli, M.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Vijayanagar, R.
Right arrow Articles by Cortelli, M.
Asian Cardiovasc Thorac Ann 1998;6:279-284
© 1998 Asia Publishing EXchange Pte Ltd

ORIGINAL CONTRIBUTION

Aortic Valve Replacement Without Annular Enlargement in Patients with Small Aortic Roots

Raghavendra Vijayanagar, MD, Gary Chan, DPharm, Rao Musunuru, MD, Narendra Sastry, MD, Ira Siegman, MD, Narayana Rattehalli, MD, Michael Cortelli, MD

Section of Thoracic and Cardiovascular Surgery Tampa General Hospital Tampa, FL, USA Section of Thoracic and Cardiovascular Surgery Heart Institute at Bayonet Point Regional Medical Center Hudson, FL, USA
For reprint information contact: Raghavendra Vijayanagar, MD Section of Thoracic and Cardiovascular Surgery Tampa General Hospital Four Columbia Drive, Suite 830 Tampa, FL 33606, USA Tel:1 813 251 0526 Fax:1 813 254 4697

   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Use of small prostheses for aortic valve replacement eliminates the need for annular enlargement but may impair symptomatic resolution and long-term patient survival. We reviewed our experience with 105 consecutive patients who had isolated aortic valve replacement with small mechanical prostheses or bioprostheses (14 to 21 mm) without concurrent annular enlargement between August 1976 and November 1992. The mean age was 72 ± 10 years and 82% of patients were female. Valvular disease was primarily aortic stenosis in 61%, aortic regurgitation in 7%, and mixed aortic disease was present in 32% of patients. Mean preoperative ejection fraction was 64% ± 17% and the aortic valve area was 0.5 ± 0.2 cm2. Prior to surgery, 82% of patients were in New York Heart Association functional class III or IV. The mean duration of follow-up was 8.1 years. There were 7 early and 14 late deaths giving an overall survival of 80% and a 10-year Kaplan-Meier survival rate of 77%. Five patients developed thromboembolic complications (transient stroke) and 2 required repeat aortic valve replacement due to prosthetic valve endocarditis. Doppler echocardiography or cardiac catheterization was performed in 15 patients postoperatively but peak systolic gradient exceeded 50 mm Hg in only one individual with a 21-mm porcine valve. All surviving patients were in functional class I or II. We conclude that aortic valve replacement with small prostheses is associated with excellent long-term patient survival, improvement in clinical symptoms, and a low incidence of complications.


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
PATIENTS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
The practice of aortic valve surgery began with animal experiments conducted by Horace Smithy in the 1940s with transvalvular and transventricular dilatation of aortic valves.1 Further progress was achieved by the development of early prosthetic valves.2,3 Over time, there were continuous innovations in the design of aortic valve prostheses, resulting in improvement in the ease of implantation, blood compatibility, and hemodynamics. For example, the development of the Starr-Edwards ball and cage aortic and mitral valve prostheses dramatically improved the survival of patients with aortic valve problems.4 As progress continued to be made in aortic valve surgery, complications associated with prosthetic valves also became evident. Implantation of valve prostheses in patients with small aortic roots presented a particular challenge. This problem is especially relevant in elderly female patients. The original small ball valve and tilting-disc valve (Starr-Edwards and Björk-Shiley valves) were associated with significant hemodynamic impairment and postoperative complications. Realization of these problems prompted the development of alternatives such as the St. Jude Medical valve, the Lillehei- Kaster valve, and modified orifice tissue valves.5–24 However, the long-term clinical consequences following implantation of small diameter aortic prostheses without annular enlargement remain controversial.25,26


   PATIENTS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
We reviewed the medical record of 105 consecutive patients who underwent isolated implantation of size 14-mm to 21-mm prostheses for aortic valve replacement. These patients received mechanical valves or bioprostheses without annular enlargement, between August 1976 and November 1992. Patients were excluded if they underwent concomitant coronary artery bypass surgery or other cardiac operations. All patients had been followed up for at least one year after aortic valve replacement. Follow-up data were updated through November 1993. The mean follow-up duration was 8.1 ± 9.4 years with a range of 1.0 ± 17.2 years.

The mean age of the study cohort was 72 ± 10 years with a range of 27 to 87 years. Of the 105 patients, 96 (91%) were at least 60 years old. The majority of patients (82%) were female. Most of the patients (82%) were in New York Heart Association functional class III or IV before undergoing aortic valve surgery. Sixty-four patients (61%) had aortic stenosis as the predominant cause of their valvular disease, whereas aortic regurgitation was the primary finding in 7 patients (7%). Mixed aortic disease, with characteristics of both valvular stenosis and regurgitation, was present in the remaining 34 patients (32%). Concomitant mitral regurgitation was present in 12 patients and 2 other individuals presented with mild mitral stenosis. Eleven patients (10%) had diabetes mellitus, 48 (46%) had hypertension, and 8 patients (8%) had a history of cerebrovascular accidents. Prior to valvular surgery, the mean ejection fraction (ascertained by ventriculogram or echocardiogram) was 63.9% ± 17.3%, mean pulmonary artery pressure was 24.5 ± 11.2 mm Hg, and the calculated aortic valve area was 0.5 ± 0.2 cm2. The patient characteristics among individuals receiving different types of aortic valve prosthesis are listed in Table 1Go. The nature of aortic valve disease was determined by reviewing the findings of cardiac catheterization. Left ventricular ejection fraction was estimated from a contrast ventriculogram or echocardiogram. Aortic valve area was calculated with the Gorlin formula.


View this table:
[in this window]
[in a new window]
  		Table 1. Characteristics of Patients Receiving Different Types of Aortic Valves
 
Three patients required aortic valve replacement after cardiac catheterization on an urgent basis; the other patients underwent an elective procedure. Standard techniques of cardiopulmonary bypass were used in all operations. Prior to 1977, aortic valve surgery was carried out without cardioplegia. During that period, systemic hypothermia at 28°C to 30°C and topical saline cooling of the heart was employed. From 1977, crystalloid cardioplegic solution was injected via the aortic root in addition to the application of topical hypothermia. Retrograde cardioplegia was not applied in this study population. Interrupted nonabsorbable sutures with or without pledgets were used.

Our policy was to implant tissue valves in elderly patients and to use mechanical prostheses in younger individuals when anticoagulation was not contraindicated. The aortic valve prostheses used in this patient population are shown in Table 2Go. The current high-profile orifice St. Jude Medical valve, low-profile Carbomedics valve, and the recently developed modified orifice tissue valves were not available during the initial study period. Our experience with the 19-mm St. Jude Medical valve began in 1979, prior to its approval by the Food and Drug Administration.


View this table:
[in this window]
[in a new window]
  		Table 2. Characteristics of Aortic Valve Prostheses in 105 Patients
 

   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Seven patients died within 30 days after aortic valve replacement, resulting in a 30-day mortality of 7%. Three of these were intraoperative deaths and 4 occurred in the early postoperative period. The causes of death are shown in Table 3Go. Thromboembolic complications in the early postoperative period were documented in 3 patients who suffered cerebrovascular accidents with transient neurological deficits. In addition, excessive bleeding at the surgical site required reoperation in 6 individuals.


View this table:
[in this window]
[in a new window]
  		Table 3. Causes of Death within 30 Days after Aortic Valve Replacement
 
There were 14 late deaths recorded up to November 1993. Therefore, a total of 21 patients had expired by the last follow-up, resulting in an overall patient survival rate of 81%. The survival curve for the entire study group is shown in Figure 1Go. The 10-year Kaplan-Meier survival rate was 77%. Warfarin and antiplatelet therapy (aspirin and/or dipyridamole) were administered in 50% and 30% of patients, respectively, for prophylaxis against thromboembolic complications. All patients with a mechanical prosthesis received warfarin therapy. Antiplatelet agents were used in patients with tissue valves. Late thromboembolic events were noted in 3 patients, including one who had developed a previous embolic stroke within 30 days after aortic valve replacement. Two of these patients experienced transient ischemic attacks and another showed residual neurological deficits after a stroke. The Carpentier-Edwards porcine bioprosthetic valve was implanted in 2 of these individuals and the other patient received an Ionescu-Shiley pericardial valve. Mild anticoagulant-related hemorrhage occurred in 2 other patients. There were 2 cases of endocarditis requiring explantation of the valve prostheses and repeat aortic valve replacement. One of these patients received an Ionescu-Shiley (19-mm) pericardial valve at the initial aortic valve replacement surgery and the other had a Medtronic-Hall (21-mm) tilting-disc valve. Overall, differential clinical outcomes were not obviously associated with different types of aortic valve prostheses in the early or late postoperative periods (Table 4Go).



View larger version (6K):
[in this window]
[in a new window]
  		Figure 1. Kaplan-Meier survival curve for 105 consecutive patients who underwent isolated implantation of small aortic valve prostheses.

 

View this table:
[in this window]
[in a new window]
  		Table 4. Deaths and Thromboembolic Events in Patients Receiving Different Types of Aortic Valve Prostheses in Early (<=30 days) and Late (>30 days) Postoperative Periods
 
All surviving patients were in New York Heart Association function class I or II at the last follow-up. Doppler echocardiography or cardiac catheterization was performed in 15 patients after aortic valve replacement; peak systolic aortic valve gradient exceeded 50 mm Hg in only one clinically stable patient who received a 21-mm porcine valve. The aortic valve gradient determined by cardiac catheterization was not significant in 3 patients who received 14-mm Lillehei-Kaster valves.


   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
The majority of patients included in our analysis were elderly women who had small aortic roots. In these individuals, we intentionally avoided using 19-mm porcine valves and selected small-diameter mechanical prostheses, preferably St. Jude Medical bileaflet valves. In our earlier experience before suitable small-diameter prostheses were available, it was our practice to perform aortic root enlargement. After the advent of the 19-mm St. Jude Medical valve, aortic annular enlargement was no longer carried out because excellent hemodynamics had been documented with this valve. Our data demonstrated that hemodynamic improvement was achieved after aortic valve replacement with small-diameter prostheses. Of the 15 patients who had repeat cardiac catheterization or a Doppler echocardiogram after aortic valve replacement, peak systolic valve gradient exceeded 50 mm Hg in only one patient who received the 21-mm porcine valve and this patient was clinically stable. Three of the patients who received the smallest valves (14-mm Lillehei-Kaster) did not have significant gradients as measured by cardiac catheterization. Peak systolic gradients after exercise were not measured in our study population.

Other authors have reported similar experiences to ours of improved hemodynamics after replacement with various small-diameter valve prostheses such as the Sorin tilting-disc prosthesis, Carbomedics aortic valve prosthesis, St. Jude Medical (modified orifice) valve, and Carpentier- Edwards bioprostheses (19-mm to 2l-mm).11,16,18,22,23 On the other hand, the groups of Kawachi17 and Kratz19 advocated enlargement of the aortic annulus and the use of larger aortic valve prostheses, particularly in patients with body surface areas above 1.9 m2. In their experience with 132 small pericardial valves, Teoh and colleagues5 observed significant gradients across 19-mm prostheses with peak exercise, although these patients were clinically improved after surgery. Similarly, Bojar and colleagues12 reported elevated postoperative gradients in 117 clinically stable patients who received 17-mm or 19-mm pericardial valves. With the accumulation of clinical experience, we have elected to discontinue the use of Ionescu-Shiley pericardial valves due to their high failure rate (not described in the study). Masters and colleagues10 have also reported their discontinuation of Ionescu-Shiley pericardial valves because of a high failure rate.

In the extensive experience of Craver and colleagues6 with aortic valve surgery, the early mortality rate increased from 2.5% for patients under 70 years old to 7.3% for those over the age of 70. Similarly, in our series of mostly elderly patients, the 30-day mortality was 7%. The overall patient survival rate of 81% in our series is also consistent with published data for the elderly population.5–26 Only 2 patients required repeat valve replacement due to prosthetic endocarditis. Our findings therefore support the accumulating evidence of improved survival after aortic valve surgery in the elderly. As a result, aortic valve surgery in the elderly has become quite commonplace since the 1980s.

A variety of mechanical and tissue prosthetic valves were used in our patients. However, different valve prostheses were not apparently associated with differential clinical outcome. In the entire series, only 6 episodes of thromboembolic complications developed in 5 patients and few anticoagulant-related bleeding episodes were observed. These observations were supportive of the findings of previous studies. In patients who received allograft, xenograft, or mechanical aortic valve prostheses, McGiffin and colleagues15 concluded that the risk of death was not related to the type of implanted valve prosthesis but to the impaired left ventricular function resulting from preexisting aortic valve disease. Borkon and colleagues8 also reported that there was no difference in the prevalence of thromboembolic events between recipients of bioprosthetic valves and mechanical valves, although patients who received tissue valves experienced fewer anticoagulant-related bleeding complications. In a more recent study, Fiore and colleagues23 also observed no difference in the performance of the St. Jude Medical and Medtronic-Hall valves for aortic valve replacement in patients with small aortic annuli.

Aortic valve replacement in patients with small aortic roots has historically presented a challenge and concerns over its long-term clinical outcome have been raised. In particular, implantation of small mechanical or tissue prosthetic valves may be associated with increased risks of hemodynamic impairment, thromboembolic complications, and mortality. In this study, we observed good long-term patient survival and a low incidence of thromboembolic or anticoagulant-related complications. Our findings suggest that implantation of valvular prostheses in patients with small aortic roots without annular enlargement is a surgical problem mostly resolved with new generations of mechanical and tissue valves.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Smithy HG, Pratt-Thomas HR, Deyerle HP. Aortic valvulotomy: experimental methods and early results. Surg Gynec Obstet 1948;86:513–23.

  2. Hufnagel CA. Aortic plastic valvular prosthesis. Bull Georgetown U Med Cent 1951;4:128–9.

  3. Campbell JM. An artificial aortic valve. J Thorac Surg 1950;19:312–8.

  4. Starr A, Edwards ML, McCord CW, Griswold HE. Aortic replacement: clinical experience with a semi-rigid ball valve prosthesis. Circulation 1963;27:779–83.[Abstract/Free Full Text]

  5. Teoh KH, Fulop JC, Weisel RD, Ivanov J, Tong CP, Slattery SA, et al. Aortic valve replacement with a small prosthesis. Circulation 1987;76(Suppl III):III-123–31.

  6. Craver JM, Weintraub WS, Jones EL, Guyton RA, Hatcher CR Jr. Predictors of mortality, complications, and length of stay in aortic valve replacement for aortic stenosis. Circulation 1988;78(Suppl I):I-85–90.

  7. Levinson JR, Akins CW, Buckley MJ, Newell JB, Palacios IF, Block PC, et al. Octogenarians with aortic stenosis-outcome after aortic valve replacement. Circulation 1989:80(Suppl I):I-49–56.

  8. Borkon AM, Soule LM, Baughman KL, Baumgartner WA, Gardner TJ, Watkins L, et al. Aortic valve selection in the elderly patient. Ann Thorac Surg 1988;46:270–7.[Abstract]

  9. Galloway AC, Colvin SB, Grossi EA, Baumann FG, Sabban YP, Esposito R, et al. Ten-year experience with aortic valve replacement in 482 patients 70 years of age or older: operative risk and long-term results. Ann Thorac Surg 1990;49:84–93.[Abstract]

  10. Masters RG, Pipe AL, Bedard JP, Brais MP, Goldstein WG, Koshal A, et al. Long-term clinical results with the Ionescu-Shiley pericardial xenograft. J Thorac Cardiovasc Surg 1991;101:81–9.[Abstract]

  11. Calafiore AM, Santarelli P, Glieca F, Luciani N, Maddestra N, Paloscia L, et al. Valve replacement with the tilting-disc Sorin prosthesis in patients with narrow aortic annulus. J Cardiovasc Surg 1988:29:387–91.[Medline]

  12. Bojar RM, Diehl JT, Moten M, Payne DD, Rastegar H, Stetz JJ, et al. Clinical and hemodynamic performance of the Ionescu-Shiley valve in the small aortic root. J Thorac Cardiovasc Surg 1989;98:1087–95.[Abstract]

  13. Sethi GK. Should aortic valve replacement be performed in elderly patients? Ann Thorac Surg 1988;46:262–3.[Medline]

  14. Culliford AT, Galloway AC, Colvin SB, Grossi EA, Baumann FG, Esposito R, et al. Aortic valve replacement for aortic stenosis in persons aged 80 years and over. Am J Cardiol 1991;67:1256–60.[Medline]

  15. McGiffin DC, O'Brien MF, Galbraith AJ, McLachlan GJ, Stafford EG, Gardner MA, et al. An analysis of risk factors for death and mode specific death aortic valve replacement with allograft, xenograft, and mechanical valves. J Thorac Cardiovasc Surg 1993;106:895–911.[Abstract]

  16. Frater RWM, Salomon NW, Rainer WG, Cosgrove DM, Wickham E. The Carpentier-Edwards pericardial aortic valve: intermediate results. Ann Thorac Surg 1992;53: 764–71.[Abstract]

  17. Kawachi Y, Tominaga R, Tokunaga K. Eleven-year follow-up study of aortic or aortic-mitral annulus-enlarging procedures by Manouguian's technique. J Thorac Cardiovasc Surg 1992;104:1259–63.[Abstract]

  18. De Paulis R, Sommariva L, Russo F, Tomai F, Tondo A, Pagliaricci C, et al. Doppler echocardiography evaluation of the CarboMedics valve in patients with small aortic annulus and valve prosthesis-body surface area mismatch. J Thorac Cardiovasc Surg 1994;108:57–62.[Abstract/Free Full Text]

  19. Kratz JM, Sade RM, Crawford FA Jr, Crumbley AJ III, Stroud MR. The risk of small St. Jude aortic valve prostheses. Ann Thorac Surg 1994;57:1114–9.[Abstract]

  20. Gonzalez-Juanatey JR, García-Acuña JM, Vega-Fernandez M, Amaro-Cendon A, Castelo-Fuentes V, Garcia-Bengoechea JB, et al. Influence of the size of aortic valve prostheses on hemodynamics and change in left ventricular mass: implications for the surgical management of aortic stenosis. J Thorac Cardiovasc Surg 1996;112:273–80.[Abstract/Free Full Text]

  21. He GW, Grunkemeier GL, Gately HL, Furnary AP, Starr A. Up to thirty-year survival after aortic valve replacement in the small aortic root. Ann Thorac Surg 1995;59:1056–62.[Abstract/Free Full Text]

  22. Carrel T, Zingg U, Jenni UZ, Aeschbacher B, Turina MI. Early in vivo experience with the hemodynamic plus St. Jude Medical heart valves in patients with narrowed aortic annulus. Ann Thorac Surg 1996;61:1418–22.[Abstract/Free Full Text]

  23. Fiore AC, Swartz M, Grunkemeier GL, Dressler F, Peigh PS, McBride LR, et al. Valve replacement in the small aortic annulus: prospective randomized trial of St. Jude with Medtronic-Hall. Eur J Cardio-thorac Surg 1997;11: 485–91.[Abstract]

  24. Sawant D, Singh AK, Feng WC, Bert AA, Rotenberg F. Nineteen-millimeter aortic St. Jude Medical heart valve prosthesis: up to sixteen years' follow-up. Ann Thorac Surg 1997;63:964–70.[Abstract/Free Full Text]

  25. Kitamura M, Satoh M, Hachida M, Endo M, Hashimoto A, Koyanagi H. Aortic valve replacement in small aortic annulus with or without annular enlargement. J Heart Valve Dis 1996;5(Suppl 3):S289–93.

  26. Sommers KE, David TE. Aortic valve replacement with patch enlargement of the aortic annulus. Ann Thorac Surg 1997;63:1608–12.[Abstract/Free Full Text]





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 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):
Raghavendra Vijayanagar
Narendra Sastry
Ira Siegman
Narayana Rattehalli
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vijayanagar, R.
Right arrow Articles by Cortelli, M.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Vijayanagar, R.
Right arrow Articles by Cortelli, M.

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