Asian Cardiovascular and Thoracic Annals http://aan.sagepub.com/
Valve prosthesis-patient mismatch: A surgeon's solution Arkalgud Sampath Kumar Asian Cardiovascular and Thoracic Annals 2014 22: 647 DOI: 10.1177/0218492314539226 The online version of this article can be found at: http://aan.sagepub.com/content/22/6/647
Published by: http://www.sagepublications.com
On behalf of:
The Asian Society for Cardiovascular Surgery
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Editorial
Valve prosthesis-patient mismatch: A surgeon’s solution
As the term suggests, prosthesis-patient mismatch (PPM) is a creation of the surgeon. The stenotic aortic valve produces this problem for the patient. When a patient seeking relief gets PPM, he pays a very high cost. Rahimtoola1 coined this term for the ineffective and unwanted problem that surgeons create. There are a large number of publications and meta-analyses of articles addressing this problem in aortic valve replacement.2–8 In the four decades of my experience, I have conscientiously avoided this problem in my patients. I would like to share this experience. How many aortic valve replacements have I performed? I have no accurate count but it is in excess of 5000 mechanical and tissue valve implantations. Excluded from this are patients who received aortic valve repairs, reconstructions and replacement with valved conduits, autografts, and homografts. Pibarot and Dumesnil6 and others suggested a novel method for predicting the effective orifice area at surgery and reducing PPM in their patients.7 There are many studies suggesting high gradients and greater PPM in patients receiving 19-mm or 21-mm St. Jude Medical mechanical valves. A few authors have cautioned against the use of these small prostheses.2–5,8 There are practically no publications reporting significant PPM with 23-mm or larger mechanical or tissue valves in any population. We have adopted our own method of reducing or abolishing this problem. Our strategy has provided excellent results in terms of low early mortality, lower late mortality, and use of a larger valve. Despite my teaching, I must confess that my students and colleagues have been reluctant to use these techniques and continue to implant smaller valves. Our studies in fresh cadaver homografts in India showed that the mean aortic annulus diameter in men (16–60-years old) was 23.2 1.9 mm, and in women (16–45-years old), it was 21.2 2.5 mm.9 These correspond to an aortic valve area of 4.2 cm2 (range 3.6 to 4.9 cm2) in men and 3.5 cm2 (range 2.8 to 4.4 cm2) in women. Barring root replacement with homografts and autografts, such high orifice areas cannot be provided by any other implantable substitute. The best we can do is to implant a St. Jude Medical mechanical valve size 23-mm to 31-mm (model nos. AJ-501, AHPJ-505; St. Jude Medical, Inc., St. Paul, MN, USA) or tissue
Asian Cardiovascular & Thoracic Annals 2014, Vol. 22(6) 647–648 ß The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0218492314539226 aan.sagepub.com
valves which are not likely to produce PPM. Therefore, it is necessary to implant a valve size of 25 mm or more in adult males and 23 mm or more in adult females. Our published results in patients undergoing aortic valve replacement for aortic stenosis show that nearly 80% of patients received a prosthesis of 23 mm or larger, and 54% received a 25-mm or larger valve.10 Only 3% of patients received a 19-mm prosthesis; one was a child with a body surface area less than 1 m2 and two were adult women with a body surface area less than 1.5 m2. These are small patients compared to the Caucasian population. The mean body surface area was 1.5 0.2 m2, and none exceeded 2.0 m2. None received a 17-mm prosthesis, and no root enlargement was performed in any patient. There were no early or late deaths at a median follow-up period of 26.5 months. We have also published our observation on the surgeon as a variable for implantation of a larger prosthesis.9 It was clear from this study that the actual size of prosthesis implanted was primarily determined by the surgeon and not always by the measured aortic annulus diameter. In a small group of patients over a 6-year period, we implanted large 31-mm and 33-mm (reversed mitral) St. Jude Medical prostheses in the aortic position.11 These included patients who presented with aortic regurgitation with or without stenosis. These patients demonstrated excellent exercise tolerance. We did not encounter any aortic root disruption in these patients with large prostheses. It is pertinent to point out that in none of these studies have we enlarged the aortic root. Postoperatively, patients have been asymptomatic and with low gradients. However, we have not particularly addressed PPM as defined, since the immediate and early postoperative echocardiography revealed no significant gradients. If this experience has a limitation it is not estimating the effective orifice area after surgery. The absence of symptoms, the low postoperative gradients, and the absence any published data on PPM with 23-mm and larger valves were reasons for not addressing effective orifice area. The complete absence of mortality in isolated aortic stenosis and the extremely low mortality (1.9%) in the larger experience of aortic valve replacement are pointers towards effective relief of obstruction.9,10
Downloaded from aan.sagepub.com at UNIV OF PENNSYLVANIA on December 1, 2014
648
Asian Cardiovascular & Thoracic Annals 22(6)
Our technique is simple and has been described earlier. A low aortotomy extending into the noncoronary sinus is our choice. The aortic valve is pulled up by strong traction on 3 stay sutures placed at the top of the commissural pillars. The heart must be fully arrested and flaccid. Calcification and fibrous thickening are dealt with by aggressive debridement. On completion of valve excision, the surgeon and assistant palpate the aortic annulus for any residual calcium. All calcific granules are meticulously removed. Thickened fibrous layers are peeled from both the annulus and subannular left ventricular outflow tract, including the anterior mitral leaflet. The annulus is now sized and the prosthesis is chosen when the largest sizer fits snugly in the annulus and can be eased into the left ventricular outflow tract without tilting; this is the size of prosthesis that is selected for implantation. The valve is sutured with simple interrupted sutures without pledgets. Between 18 and 21 sutures are used. The valve is lowered and gently coaxed into the annulus and left ventricular outflow tract. The sutures are tied, and the coronary ostia are inspected for any obstruction. I have observed that a surgeon’s attitude towards aortic stenosis to a great extent determines the valve size. Fear and ignorance rule the mind as well as a desire to avoid any difficulty, real or imagined. Aortic stenosis triggers a cautious approach and a small prosthesis. A high aortotomy, incomplete valve debridement, incomplete decalcification, residual fibrosis, and the use of pledgeted sutures are possible risk factors for implanting a small prosthesis and consequent PPM. It would have been preferable if the manufacturers did not make a 17-mm prosthesis. Availability of a small prosthesis is the reason for its use. Unfamiliarity with the surgical anatomy of the aortic root and fear of disruption are the reasons for the small prosthesis choice. I have had no aortic root disruption in my experience, even when a large valve (31–33 mm) is used. It has been my endeavor to implant the largest size of prosthesis that fits the annulus, irrespective of measurements before or at surgery. In a large number of patients, the size of the annulus in the flaccid arrested heart exceeds the measured diameter after complete excision of the valve, calcium, and fibrous thickening. An open mind enlarges the aortic root much better than any root enlargement technique. This editorial may appear provocative and may be criticized as a pompous presentation with scant evidence. I would agree with that observation. However, if it challenges you to implant a larger valve in your next patient with aortic stenosis, it would be most satisfying.
Funding This research received no specific grant from any funding agency in the public, commerical, or not-for-profit sectors.
Conflict of interest statement None declared.
References 1. Rahimtoola SH. The problem of valve prosthesis-patient mismatch. Circulation 1978; 58: 20–24. 2. Gonza´lez-Juanatey JR, Garcı´ a-Acun˜a JM, Vega Fernandez M, et al. Influence of the size of aortic valve prostheses on hemodynamics and change in left ventricular mass. J Thorac Cardiovasc Surg 1996; 112: 273–280. 3. Blackstone EH, Cosgrove DM, Jamieson WR, et al. Prosthesis size and survival after aortic valve replacement. J Thorac Cardiovasc Surg 2003; 126: 783–796. 4. Milano AD, De Carlo M, Mecozzi G, et al. Clinical outcome in patients with 19-mm and 21-mm St. Jude aortic prostheses: comparison at long-term follow-up. Ann Thorac Surg 2002; 73: 37–43. 5. Blais C, Dumesnil JG, Baillot R, Simard S, Doyle D and Pibarot P. Impact of valve prosthesis-patient mismatch on short term mortality after aortic valve replacement. Circulation 2003; 108: 983–988. 6. Pibarot P. Dumesnil G, Prevention of valve prosthesispatient mismatch before aortic valve replacement. Heart 2007; 93: 549–551. 7. Bleiziffer S, Eichinger W, Hettich I, et al. Prediction of valve prosthesis-patient mismatch before aortic valve replacement. Heart 2007; 93: 615–620. 8. Kratz JM, Sade RM, Crawford FA, Crumbley AJ and Stroud MR. The risk of small St. Jude aortic prostheses. Ann Thorac Surg 1994; 57: 1114–1118. 9. Choudhary SK, Mathur A, Venugpal P, et al. Prosthesis size in aortic valve replacement: surgeon-related variable. Asian Cardiovasc Thorac Ann 2000;8:333–8. Available at: http://aan.sagepub.com/content/8/4/333.full.pdfþ html. Accessed May 18, 2014. 10. Joshi K, Talwar S, Velayoutham D and Sampath Kumar A. Aortic valve replacement in predominant aortic stenosis: what is an appropriate size valve? Ind J Thorac Cardiovasc Surg 2007;23:141–5. Available at: http://medind.nic.in/ibq/t07/i2/ibq/ t07i2p141.pdf. Accessed May 18, 2014. 11. Gupta G, Roy A and Sampath Kumar A. Aortic valve replacement with 31- and 33- mm mechanical prostheses. Tex heart Inst J 2004; 31: 149–152.
Arkalgud Sampath Kumar Pushpanjali Crosslay Hospital, Vaishali, Ghaziabad, Uttar Pradesh, India Email: [email protected]
Downloaded from aan.sagepub.com at UNIV OF PENNSYLVANIA on December 1, 2014
Valve prosthesis-patient mismatch: A surgeon's solution Arkalgud Sampath Kumar Asian Cardiovascular and Thoracic Annals 2014 22: 647 DOI: 10.1177/0218492314539226 The online version of this article can be found at: http://aan.sagepub.com/content/22/6/647
Published by: http://www.sagepublications.com
On behalf of:
The Asian Society for Cardiovascular Surgery
Additional services and information for Asian Cardiovascular and Thoracic Annals can be found at: Email Alerts: http://aan.sagepub.com/cgi/alerts Subscriptions: http://aan.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav
>> Version of Record - Jul 1, 2014 What is This?
Downloaded from aan.sagepub.com at UNIV OF PENNSYLVANIA on December 1, 2014
Editorial
Valve prosthesis-patient mismatch: A surgeon’s solution
As the term suggests, prosthesis-patient mismatch (PPM) is a creation of the surgeon. The stenotic aortic valve produces this problem for the patient. When a patient seeking relief gets PPM, he pays a very high cost. Rahimtoola1 coined this term for the ineffective and unwanted problem that surgeons create. There are a large number of publications and meta-analyses of articles addressing this problem in aortic valve replacement.2–8 In the four decades of my experience, I have conscientiously avoided this problem in my patients. I would like to share this experience. How many aortic valve replacements have I performed? I have no accurate count but it is in excess of 5000 mechanical and tissue valve implantations. Excluded from this are patients who received aortic valve repairs, reconstructions and replacement with valved conduits, autografts, and homografts. Pibarot and Dumesnil6 and others suggested a novel method for predicting the effective orifice area at surgery and reducing PPM in their patients.7 There are many studies suggesting high gradients and greater PPM in patients receiving 19-mm or 21-mm St. Jude Medical mechanical valves. A few authors have cautioned against the use of these small prostheses.2–5,8 There are practically no publications reporting significant PPM with 23-mm or larger mechanical or tissue valves in any population. We have adopted our own method of reducing or abolishing this problem. Our strategy has provided excellent results in terms of low early mortality, lower late mortality, and use of a larger valve. Despite my teaching, I must confess that my students and colleagues have been reluctant to use these techniques and continue to implant smaller valves. Our studies in fresh cadaver homografts in India showed that the mean aortic annulus diameter in men (16–60-years old) was 23.2 1.9 mm, and in women (16–45-years old), it was 21.2 2.5 mm.9 These correspond to an aortic valve area of 4.2 cm2 (range 3.6 to 4.9 cm2) in men and 3.5 cm2 (range 2.8 to 4.4 cm2) in women. Barring root replacement with homografts and autografts, such high orifice areas cannot be provided by any other implantable substitute. The best we can do is to implant a St. Jude Medical mechanical valve size 23-mm to 31-mm (model nos. AJ-501, AHPJ-505; St. Jude Medical, Inc., St. Paul, MN, USA) or tissue
Asian Cardiovascular & Thoracic Annals 2014, Vol. 22(6) 647–648 ß The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0218492314539226 aan.sagepub.com
valves which are not likely to produce PPM. Therefore, it is necessary to implant a valve size of 25 mm or more in adult males and 23 mm or more in adult females. Our published results in patients undergoing aortic valve replacement for aortic stenosis show that nearly 80% of patients received a prosthesis of 23 mm or larger, and 54% received a 25-mm or larger valve.10 Only 3% of patients received a 19-mm prosthesis; one was a child with a body surface area less than 1 m2 and two were adult women with a body surface area less than 1.5 m2. These are small patients compared to the Caucasian population. The mean body surface area was 1.5 0.2 m2, and none exceeded 2.0 m2. None received a 17-mm prosthesis, and no root enlargement was performed in any patient. There were no early or late deaths at a median follow-up period of 26.5 months. We have also published our observation on the surgeon as a variable for implantation of a larger prosthesis.9 It was clear from this study that the actual size of prosthesis implanted was primarily determined by the surgeon and not always by the measured aortic annulus diameter. In a small group of patients over a 6-year period, we implanted large 31-mm and 33-mm (reversed mitral) St. Jude Medical prostheses in the aortic position.11 These included patients who presented with aortic regurgitation with or without stenosis. These patients demonstrated excellent exercise tolerance. We did not encounter any aortic root disruption in these patients with large prostheses. It is pertinent to point out that in none of these studies have we enlarged the aortic root. Postoperatively, patients have been asymptomatic and with low gradients. However, we have not particularly addressed PPM as defined, since the immediate and early postoperative echocardiography revealed no significant gradients. If this experience has a limitation it is not estimating the effective orifice area after surgery. The absence of symptoms, the low postoperative gradients, and the absence any published data on PPM with 23-mm and larger valves were reasons for not addressing effective orifice area. The complete absence of mortality in isolated aortic stenosis and the extremely low mortality (1.9%) in the larger experience of aortic valve replacement are pointers towards effective relief of obstruction.9,10
Downloaded from aan.sagepub.com at UNIV OF PENNSYLVANIA on December 1, 2014
648
Asian Cardiovascular & Thoracic Annals 22(6)
Our technique is simple and has been described earlier. A low aortotomy extending into the noncoronary sinus is our choice. The aortic valve is pulled up by strong traction on 3 stay sutures placed at the top of the commissural pillars. The heart must be fully arrested and flaccid. Calcification and fibrous thickening are dealt with by aggressive debridement. On completion of valve excision, the surgeon and assistant palpate the aortic annulus for any residual calcium. All calcific granules are meticulously removed. Thickened fibrous layers are peeled from both the annulus and subannular left ventricular outflow tract, including the anterior mitral leaflet. The annulus is now sized and the prosthesis is chosen when the largest sizer fits snugly in the annulus and can be eased into the left ventricular outflow tract without tilting; this is the size of prosthesis that is selected for implantation. The valve is sutured with simple interrupted sutures without pledgets. Between 18 and 21 sutures are used. The valve is lowered and gently coaxed into the annulus and left ventricular outflow tract. The sutures are tied, and the coronary ostia are inspected for any obstruction. I have observed that a surgeon’s attitude towards aortic stenosis to a great extent determines the valve size. Fear and ignorance rule the mind as well as a desire to avoid any difficulty, real or imagined. Aortic stenosis triggers a cautious approach and a small prosthesis. A high aortotomy, incomplete valve debridement, incomplete decalcification, residual fibrosis, and the use of pledgeted sutures are possible risk factors for implanting a small prosthesis and consequent PPM. It would have been preferable if the manufacturers did not make a 17-mm prosthesis. Availability of a small prosthesis is the reason for its use. Unfamiliarity with the surgical anatomy of the aortic root and fear of disruption are the reasons for the small prosthesis choice. I have had no aortic root disruption in my experience, even when a large valve (31–33 mm) is used. It has been my endeavor to implant the largest size of prosthesis that fits the annulus, irrespective of measurements before or at surgery. In a large number of patients, the size of the annulus in the flaccid arrested heart exceeds the measured diameter after complete excision of the valve, calcium, and fibrous thickening. An open mind enlarges the aortic root much better than any root enlargement technique. This editorial may appear provocative and may be criticized as a pompous presentation with scant evidence. I would agree with that observation. However, if it challenges you to implant a larger valve in your next patient with aortic stenosis, it would be most satisfying.
Funding This research received no specific grant from any funding agency in the public, commerical, or not-for-profit sectors.
Conflict of interest statement None declared.
References 1. Rahimtoola SH. The problem of valve prosthesis-patient mismatch. Circulation 1978; 58: 20–24. 2. Gonza´lez-Juanatey JR, Garcı´ a-Acun˜a JM, Vega Fernandez M, et al. Influence of the size of aortic valve prostheses on hemodynamics and change in left ventricular mass. J Thorac Cardiovasc Surg 1996; 112: 273–280. 3. Blackstone EH, Cosgrove DM, Jamieson WR, et al. Prosthesis size and survival after aortic valve replacement. J Thorac Cardiovasc Surg 2003; 126: 783–796. 4. Milano AD, De Carlo M, Mecozzi G, et al. Clinical outcome in patients with 19-mm and 21-mm St. Jude aortic prostheses: comparison at long-term follow-up. Ann Thorac Surg 2002; 73: 37–43. 5. Blais C, Dumesnil JG, Baillot R, Simard S, Doyle D and Pibarot P. Impact of valve prosthesis-patient mismatch on short term mortality after aortic valve replacement. Circulation 2003; 108: 983–988. 6. Pibarot P. Dumesnil G, Prevention of valve prosthesispatient mismatch before aortic valve replacement. Heart 2007; 93: 549–551. 7. Bleiziffer S, Eichinger W, Hettich I, et al. Prediction of valve prosthesis-patient mismatch before aortic valve replacement. Heart 2007; 93: 615–620. 8. Kratz JM, Sade RM, Crawford FA, Crumbley AJ and Stroud MR. The risk of small St. Jude aortic prostheses. Ann Thorac Surg 1994; 57: 1114–1118. 9. Choudhary SK, Mathur A, Venugpal P, et al. Prosthesis size in aortic valve replacement: surgeon-related variable. Asian Cardiovasc Thorac Ann 2000;8:333–8. Available at: http://aan.sagepub.com/content/8/4/333.full.pdfþ html. Accessed May 18, 2014. 10. Joshi K, Talwar S, Velayoutham D and Sampath Kumar A. Aortic valve replacement in predominant aortic stenosis: what is an appropriate size valve? Ind J Thorac Cardiovasc Surg 2007;23:141–5. Available at: http://medind.nic.in/ibq/t07/i2/ibq/ t07i2p141.pdf. Accessed May 18, 2014. 11. Gupta G, Roy A and Sampath Kumar A. Aortic valve replacement with 31- and 33- mm mechanical prostheses. Tex heart Inst J 2004; 31: 149–152.
Arkalgud Sampath Kumar Pushpanjali Crosslay Hospital, Vaishali, Ghaziabad, Uttar Pradesh, India Email: [email protected]
Downloaded from aan.sagepub.com at UNIV OF PENNSYLVANIA on December 1, 2014
