- Email: [email protected]
Minimal invasive mitral valve surgery does make a difference: Should it be the gold standard for mitral valve repair?
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E N D S I N
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A R D I O V A S C U L A R
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E D I C I N E
] (2015) ]]]–]]]
Available online at www.sciencedirect.com
www.elsevier.com/locate/tcm
Editorial Commentary
Minimal invasive mitral valve surgery does make a different: Should it be the gold standard for mitral valve repair? Danny Ramzyn, and Alfredo Trento Division of Cardiac Surgery, Cedars-Sinai Medical Center, 8700 Beverly Blvd, A3105, Los Angeles, CA
Mitral valve regurgitation is associated with significant longterm morbidities including the development of atrial fibrillation, heart failure, and shortened life expectancy. Mitral valve repair improves long-term outcome in patients with mitral regurgitation [1]. Open chest procedures remain the gold standard for mitral repair and remain the context from which to compare durability and outcomes. In the current issue of “Trends in Cardiovascular Medicine”, Khaled Algarni and his team from the Mayo Clinic provide a highly effective, evidence-based analysis of the literature regarding the advantages of minimally invasive mitral repair methods. As Algarni clearly states in his article, minimally invasive mitral valve surgery does not refer to a single procedure, but to a growing inventory of strategies to avert a full sternotomy. However, while it is impressive to note that the use of minimally invasive mitral techniques has increased by 100% over the last few years, such methods still represent merely a small portion of all mitral valve repairs [2]. Currently, minimally invasive mitral valve repairs can be subdivided into three categories. First, are those that utilize a partial sternotomy approach. Second, are the right thoracotomy methods, including the choice between open and robotic. And third, and of the most significance to the future, are the emerging transcatheter techniques of mitral repairs. As stated by Algarni and his Mayo team, minimally invasive surgical mitral valve repair, regardless of the technique, can yield comparable results to conventional open methods in terms of outcome, yet with a substantial reduction in associated morbidities. However, because of the significantly smaller incisions, the technical demands upon the surgeon
become more rigorous, and present a sharp learning curve and a new set of potential complications. Algarni and his team know that mere marketing alone cannot be sufficient to influence acceptance within the medical community. Knowing that a thoroughly persuasive case must be made, Algarni and the Mayo group offer an elegant review of the current literature, demonstrating excellent results that equal those of open methods through the use of minimally invasive techniques. Their review demonstrates a spectral array of benefits in many categories, including decreased bleeding, fewer blood transfusions, reduced ventilation time, and shorter stays in both intensive care and the hospital overall. Other benefits include fewer postoperative pain scores, a reduction in sternal complications, and a more rapid and less complicated return to normal activity. In addition, the Algarni team demonstrates that minimally invasive mitral surgery has advantages far beyond mere cosmetics. These techniques have improved quality of life measures, reduced postoperative atrial fibrillation, and hospital costs. All of these findings combine to create a resounding tour de force as a compelling case for the use of minimally invasive mitral methods. Singularly, the Algarni case underscores the many reasons that the Mayo Clinic and other leading institutions have moved to robotically assisted mitral valve surgery as the prevailing standard of care [3–7]. The primary challenge regarding minimally invasive mitral valve surgery is the significant learning curve. The steepness of this curve depends on the technique in question. The easiest minimally invasive method to adopt is the partial sternotomy approach. However, this technique offers only a
The authors have indicated there are no conflicts of interest. n Corresponding author. Tel.: þ1 310 423 1877; fax: þ1 310 423 3522. E-mail addresses: [email protected], [email protected] (D. Ramzy). http://dx.doi.org/10.1016/j.tcm.2015.02.008 1050-1738/& 2015 Elsevier Inc. All rights reserved.
2
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E N D S I N
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minimal cosmetic advantage, and still poses potential sternal complications. More significantly, all sternotomy approaches are still perceived by patients as standard as opposed to less invasive, for they still require “cutting through a bone”. Understandably aware of the pain involved and the inferior cosmetic result, the vast majority of patients simply do not want a sternotomy, especially given that some of these patients are asymptomatic. This applies not only to mitral surgery but also to all heart procedures including aortic valve surgery, MAZE procedures, and coronary artery bypass grafts. As patients hear of the possibility of minimally invasive techniques, more and more are refusing sternotomies or surgery all together. Algarni's second examined alternative method, the right thoracotomy, has been demonstrated by both Algarni and several other groups to be cosmetically superior. More importantly, it offers results equivalent to open methods, yet with less morbidity than transsternal approaches. Regardless of whether the thoracotomy is open, thoracoscopic or robotic, this intercostal approach is seen by patients as minimally invasive, for in contrast to the sternotomy, the thoracotomy does not necessitate “cracking the chest open”. It is also regarded by cardiologists as less invasive. But the significance of this perception extends far beyond cosmetics and marketing alone. Since a significant percentage of our patients are either asymptomatic or minimally systematic, it has become increasingly difficult to convince these patients to undergo conventional mitral surgery. This presents a benefit which is not routinely discussed. Widespread evidence exists that the treatment of asymptomatic mitral regurgitation is beneficial to our patients. Yet, there is a shortage of study data in regard to likelihood of asymptomatic regurgitation being treatment. Therefore, there is yet to be a study that has examined the likelihood of patients electing treatment for asymptomatic mitral regurgitation via conventional as opposed to minimal access methods. Statistics detailing the number of patients delaying repair until symptoms develop; and how many cardiologist delay referrals until symptoms or hard indications develop—are not measured, yet they play an important role in today's arena. In spite of the growing appeal of these minimally invasive methods, the drawback continues to be the steep learning curve associated with them. This is even more of a challenge with the fully endoscopic robotic approaches. Because of this learning curve, these approaches are used by only a limited number of centers and surgeons. While it remains true that they offer significant benefits over conventional and partial sternotomy approaches, these advantages are steeply reduced if only a small portion of our population has access to them. The problem is further compounded by the fact that mitral repair training is strictly limited during residency, and that minimally invasive training is available at a few centers. Additionally, referrals for mitral repairs are sent to few mitral valve expert surgeons in the first place, and many do not have minimally invasive training at all. To address the need for training, our residency programs need to make more of an effort to train our residents in mitral repair. A hands-on approach and not just a see many and do it in your practice approach. Most importantly, surgeons in training need to be paired with an expert mentor in order to avoid the risk of
M
E D I C I N E
] (2015) ]]]–]]]
adverse events due to lack of experience. The mentorship approach significantly alters the learning curve and reduces the likelihood of adverse events. Our own study in review of 300 robotic cases demonstrates that a developing surgeon with mentorship has reduced operative times and reduced complication rates when compared to his mentor's initial case series [7]. Therefore, in confronting the learning curve issue, we stress the importance of mentorship in order to reduce OR times and complications. We as a community need to increase the use of minimally invasive techniques for mitral repair for two main reasons. First is the superior overall result when compared to the conventional approach in the broad number of ways defined above. Second is not just the patient preference for mini invasive methods versus sternotomy, but rather the fact that transcatheter mitral approaches are coming and this will truly change the field for treatment of mitral valve disease in the future. As the prospect for mitral transcatheter approaches looms closer, we only need to look at the treatment for aortic stenosis in order to understand the impact of such advances. In light of success in the aortic realm, I would caution against the skeptical assumption that transcatheter approaches for the mitral valve will not make an impact on future patient treatment. These assumptions were once made for the treatment of aortic stenosis, and today a constantly growing number of aortic patients are treated via a transcatheter approach. What is becoming increasingly apparent is that more and more patients are demanding to be treated via a transcatheter approach. I have personally observed patients with a STS score of less than 3 or even 2 request a transcatheter approach, and some even refuse surgery altogether, despite being told they do not even qualify for a transcatheter valve. Inevitably, the same issues will arise in regard to mitral valve transcatheter treatment. Currently in the USA, the only transcatheter mitral repair technique is the MitraClip. The conclusion of the EVEREST II is that percutaneous mitral valve repair, although less effective at reducing MR, is not inferior to surgical repair or replacement, with a significantly reduced adverse event rate [8]. However, several questions remain. What are the longterm consequences of residual MR in the MitraClip patients. How would MitraClip perform when compared to minimally invasive mitral repair, especially when compared to total endoscopic repair? In the second half of this decade, studies will launch to examine newer mitral valve transcatheter technologies. All initial trials will focus upon inoperable patients. However, it will not be long before transcatheter mitral repairs will be studied in operable patients, as well. It does not require extensive analysis to see that if the standard approach for mitral repair is full sternotomy that this would become the comparison group for percutaneous or transcatheter approaches. When results are achieved equal to the efficacy of open repairs, and the reduction in morbidities and discomforts exceeds the results for open repairs, we can only conclude that patients themselves will drive the increase in the use of transcatheter replacements. We should strive and try to ensure that the comparison between new mitral transcatheter technologies will be made against the current minimal access repairs detailed above. However, these transcatheter methods currently can be performed in
TR
E N D S I N
C
A R D I O V A S C U L A R
a limited number of centers. This makes them acceptable for studies, but not yet feasible for the entire US population. Therefore, in anticipation of the advent of this new transcatheter mitral future, Algarni's article, which so clearly demonstrates the superiority of minimally invasive mitral surgery, should motivate our entire surgical community towards a rapid and sweeping increase in training for minimally invasive cardiac surgeons. Given the rapid growth of transcatheter procedures in the aortic theater, the reduction in morbidities and complications, and maturing patient preferences and demands, it seems inevitable to conclude that minimally invasive mitral valve surgery will eventually become the standard of care in the United States. This conclusion seems even more inevitable if repair for leaflet prolapse using MIMVS can be offered with greater than 95% certainty, a o0.5% mortality, and a reoperation rate o1% per year. Our entire community agrees that more work needs to be done in order to improve surgical outcomes and to reduce postoperative complications. Given that most patients with degenerative mitral valve disease are young, I applaud Algarni and his Mayo team for their impressive and comprehensive review, and for demonstrating conclusively that minimally invasive approaches must become the future of mitral valve repair.
re fe r en ces
[1]
Suri RM, Vanoverschelde JL, Grigioni F, Schaff HV, Tribouilloy C, Avierinos JF, et al. Association between early
M
E D I C I N E
[2]
[3]
[4]
[5]
[6]
[7]
[8]
] (2015) ]]]–]]]
3
surgical intervention vs watchful waiting and outcomes for mitral regurgitation due to flail mitral valve leaflets. J Am Med Assoc 2013;310:609–16. Gammie JS, Zhao Y, Peterson ED, O'Brien SM, Rankin JS, Griffith BP. Less-invasive mitral valve operations: trends and outcomes from the Society of Thoracic Surgeons adult cardiac surgery database. Ann Thorac Surg 2010;90:1401–8. Gillinov AM, Banbury MK, Cosgrove DM. Hemisternotomy approach for aortic and mitral valve surgery. J Card Surg 2000;15:15–20. Chitwood WR, Elbeery JR, Chapman WH, Moran JM, Lust RL, Wooden WA, et al. Video-assisted minimally invasive mitral valve surgery: the “micro-mitral” operation. J Thorac Cardiovasc Surg 1997;113:413–4. Chitwood WR Jr, Rodriguez E, Chu MW, Hassan A, Ferguson TB, Vos PW, et al. Robotic mitral valve repairs in 300 patients: a single-center experience. J Thorac Cardiovasc Surg 2008; 136:436–41. Suri RM, Burkhart HM, Daly RC, Dearani JA, Park SJ, Sundt TM 3rd, et al. Robotic mitral valve repair for all prolapse subsets using techniques identical to open valvuloplasty: establishing the benchmark against which percutaneous interventions should be judged. J Thorac Cardiovasc Surg 2011; 142:970–9. Ramzy D, Trento A, Cheng W, De Robertis MA, Mirocha J, Ruzza A, et al. Three hundred robotic-assisted mitral valve repairs: the Cedars-Sinai experience. J Thorac Cardiovasc Surg 2014;147:228–35. Feldman T, Kar S, Rinaldi M, Fail P, Hermiller J, Smalling R, et al. Percutaneous mitral repair with the MitraClip system: safety and midterm durability in the initial EVEREST (Endovascular Valve Edge-to-Edge REpair Study) cohort. J Am Coll Cardiol 2009;54:686–94, http://dx.doi.org/10.1016/j.jacc.2009. 03.077.
E N D S I N
C
A R D I O V A S C U L A R
M
E D I C I N E
] (2015) ]]]–]]]
Available online at www.sciencedirect.com
www.elsevier.com/locate/tcm
Editorial Commentary
Minimal invasive mitral valve surgery does make a different: Should it be the gold standard for mitral valve repair? Danny Ramzyn, and Alfredo Trento Division of Cardiac Surgery, Cedars-Sinai Medical Center, 8700 Beverly Blvd, A3105, Los Angeles, CA
Mitral valve regurgitation is associated with significant longterm morbidities including the development of atrial fibrillation, heart failure, and shortened life expectancy. Mitral valve repair improves long-term outcome in patients with mitral regurgitation [1]. Open chest procedures remain the gold standard for mitral repair and remain the context from which to compare durability and outcomes. In the current issue of “Trends in Cardiovascular Medicine”, Khaled Algarni and his team from the Mayo Clinic provide a highly effective, evidence-based analysis of the literature regarding the advantages of minimally invasive mitral repair methods. As Algarni clearly states in his article, minimally invasive mitral valve surgery does not refer to a single procedure, but to a growing inventory of strategies to avert a full sternotomy. However, while it is impressive to note that the use of minimally invasive mitral techniques has increased by 100% over the last few years, such methods still represent merely a small portion of all mitral valve repairs [2]. Currently, minimally invasive mitral valve repairs can be subdivided into three categories. First, are those that utilize a partial sternotomy approach. Second, are the right thoracotomy methods, including the choice between open and robotic. And third, and of the most significance to the future, are the emerging transcatheter techniques of mitral repairs. As stated by Algarni and his Mayo team, minimally invasive surgical mitral valve repair, regardless of the technique, can yield comparable results to conventional open methods in terms of outcome, yet with a substantial reduction in associated morbidities. However, because of the significantly smaller incisions, the technical demands upon the surgeon
become more rigorous, and present a sharp learning curve and a new set of potential complications. Algarni and his team know that mere marketing alone cannot be sufficient to influence acceptance within the medical community. Knowing that a thoroughly persuasive case must be made, Algarni and the Mayo group offer an elegant review of the current literature, demonstrating excellent results that equal those of open methods through the use of minimally invasive techniques. Their review demonstrates a spectral array of benefits in many categories, including decreased bleeding, fewer blood transfusions, reduced ventilation time, and shorter stays in both intensive care and the hospital overall. Other benefits include fewer postoperative pain scores, a reduction in sternal complications, and a more rapid and less complicated return to normal activity. In addition, the Algarni team demonstrates that minimally invasive mitral surgery has advantages far beyond mere cosmetics. These techniques have improved quality of life measures, reduced postoperative atrial fibrillation, and hospital costs. All of these findings combine to create a resounding tour de force as a compelling case for the use of minimally invasive mitral methods. Singularly, the Algarni case underscores the many reasons that the Mayo Clinic and other leading institutions have moved to robotically assisted mitral valve surgery as the prevailing standard of care [3–7]. The primary challenge regarding minimally invasive mitral valve surgery is the significant learning curve. The steepness of this curve depends on the technique in question. The easiest minimally invasive method to adopt is the partial sternotomy approach. However, this technique offers only a
The authors have indicated there are no conflicts of interest. n Corresponding author. Tel.: þ1 310 423 1877; fax: þ1 310 423 3522. E-mail addresses: [email protected], [email protected] (D. Ramzy). http://dx.doi.org/10.1016/j.tcm.2015.02.008 1050-1738/& 2015 Elsevier Inc. All rights reserved.
2
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E N D S I N
C
A R D I O V A S C U L A R
minimal cosmetic advantage, and still poses potential sternal complications. More significantly, all sternotomy approaches are still perceived by patients as standard as opposed to less invasive, for they still require “cutting through a bone”. Understandably aware of the pain involved and the inferior cosmetic result, the vast majority of patients simply do not want a sternotomy, especially given that some of these patients are asymptomatic. This applies not only to mitral surgery but also to all heart procedures including aortic valve surgery, MAZE procedures, and coronary artery bypass grafts. As patients hear of the possibility of minimally invasive techniques, more and more are refusing sternotomies or surgery all together. Algarni's second examined alternative method, the right thoracotomy, has been demonstrated by both Algarni and several other groups to be cosmetically superior. More importantly, it offers results equivalent to open methods, yet with less morbidity than transsternal approaches. Regardless of whether the thoracotomy is open, thoracoscopic or robotic, this intercostal approach is seen by patients as minimally invasive, for in contrast to the sternotomy, the thoracotomy does not necessitate “cracking the chest open”. It is also regarded by cardiologists as less invasive. But the significance of this perception extends far beyond cosmetics and marketing alone. Since a significant percentage of our patients are either asymptomatic or minimally systematic, it has become increasingly difficult to convince these patients to undergo conventional mitral surgery. This presents a benefit which is not routinely discussed. Widespread evidence exists that the treatment of asymptomatic mitral regurgitation is beneficial to our patients. Yet, there is a shortage of study data in regard to likelihood of asymptomatic regurgitation being treatment. Therefore, there is yet to be a study that has examined the likelihood of patients electing treatment for asymptomatic mitral regurgitation via conventional as opposed to minimal access methods. Statistics detailing the number of patients delaying repair until symptoms develop; and how many cardiologist delay referrals until symptoms or hard indications develop—are not measured, yet they play an important role in today's arena. In spite of the growing appeal of these minimally invasive methods, the drawback continues to be the steep learning curve associated with them. This is even more of a challenge with the fully endoscopic robotic approaches. Because of this learning curve, these approaches are used by only a limited number of centers and surgeons. While it remains true that they offer significant benefits over conventional and partial sternotomy approaches, these advantages are steeply reduced if only a small portion of our population has access to them. The problem is further compounded by the fact that mitral repair training is strictly limited during residency, and that minimally invasive training is available at a few centers. Additionally, referrals for mitral repairs are sent to few mitral valve expert surgeons in the first place, and many do not have minimally invasive training at all. To address the need for training, our residency programs need to make more of an effort to train our residents in mitral repair. A hands-on approach and not just a see many and do it in your practice approach. Most importantly, surgeons in training need to be paired with an expert mentor in order to avoid the risk of
M
E D I C I N E
] (2015) ]]]–]]]
adverse events due to lack of experience. The mentorship approach significantly alters the learning curve and reduces the likelihood of adverse events. Our own study in review of 300 robotic cases demonstrates that a developing surgeon with mentorship has reduced operative times and reduced complication rates when compared to his mentor's initial case series [7]. Therefore, in confronting the learning curve issue, we stress the importance of mentorship in order to reduce OR times and complications. We as a community need to increase the use of minimally invasive techniques for mitral repair for two main reasons. First is the superior overall result when compared to the conventional approach in the broad number of ways defined above. Second is not just the patient preference for mini invasive methods versus sternotomy, but rather the fact that transcatheter mitral approaches are coming and this will truly change the field for treatment of mitral valve disease in the future. As the prospect for mitral transcatheter approaches looms closer, we only need to look at the treatment for aortic stenosis in order to understand the impact of such advances. In light of success in the aortic realm, I would caution against the skeptical assumption that transcatheter approaches for the mitral valve will not make an impact on future patient treatment. These assumptions were once made for the treatment of aortic stenosis, and today a constantly growing number of aortic patients are treated via a transcatheter approach. What is becoming increasingly apparent is that more and more patients are demanding to be treated via a transcatheter approach. I have personally observed patients with a STS score of less than 3 or even 2 request a transcatheter approach, and some even refuse surgery altogether, despite being told they do not even qualify for a transcatheter valve. Inevitably, the same issues will arise in regard to mitral valve transcatheter treatment. Currently in the USA, the only transcatheter mitral repair technique is the MitraClip. The conclusion of the EVEREST II is that percutaneous mitral valve repair, although less effective at reducing MR, is not inferior to surgical repair or replacement, with a significantly reduced adverse event rate [8]. However, several questions remain. What are the longterm consequences of residual MR in the MitraClip patients. How would MitraClip perform when compared to minimally invasive mitral repair, especially when compared to total endoscopic repair? In the second half of this decade, studies will launch to examine newer mitral valve transcatheter technologies. All initial trials will focus upon inoperable patients. However, it will not be long before transcatheter mitral repairs will be studied in operable patients, as well. It does not require extensive analysis to see that if the standard approach for mitral repair is full sternotomy that this would become the comparison group for percutaneous or transcatheter approaches. When results are achieved equal to the efficacy of open repairs, and the reduction in morbidities and discomforts exceeds the results for open repairs, we can only conclude that patients themselves will drive the increase in the use of transcatheter replacements. We should strive and try to ensure that the comparison between new mitral transcatheter technologies will be made against the current minimal access repairs detailed above. However, these transcatheter methods currently can be performed in
TR
E N D S I N
C
A R D I O V A S C U L A R
a limited number of centers. This makes them acceptable for studies, but not yet feasible for the entire US population. Therefore, in anticipation of the advent of this new transcatheter mitral future, Algarni's article, which so clearly demonstrates the superiority of minimally invasive mitral surgery, should motivate our entire surgical community towards a rapid and sweeping increase in training for minimally invasive cardiac surgeons. Given the rapid growth of transcatheter procedures in the aortic theater, the reduction in morbidities and complications, and maturing patient preferences and demands, it seems inevitable to conclude that minimally invasive mitral valve surgery will eventually become the standard of care in the United States. This conclusion seems even more inevitable if repair for leaflet prolapse using MIMVS can be offered with greater than 95% certainty, a o0.5% mortality, and a reoperation rate o1% per year. Our entire community agrees that more work needs to be done in order to improve surgical outcomes and to reduce postoperative complications. Given that most patients with degenerative mitral valve disease are young, I applaud Algarni and his Mayo team for their impressive and comprehensive review, and for demonstrating conclusively that minimally invasive approaches must become the future of mitral valve repair.
re fe r en ces
[1]
Suri RM, Vanoverschelde JL, Grigioni F, Schaff HV, Tribouilloy C, Avierinos JF, et al. Association between early
M
E D I C I N E
[2]
[3]
[4]
[5]
[6]
[7]
[8]
] (2015) ]]]–]]]
3
surgical intervention vs watchful waiting and outcomes for mitral regurgitation due to flail mitral valve leaflets. J Am Med Assoc 2013;310:609–16. Gammie JS, Zhao Y, Peterson ED, O'Brien SM, Rankin JS, Griffith BP. Less-invasive mitral valve operations: trends and outcomes from the Society of Thoracic Surgeons adult cardiac surgery database. Ann Thorac Surg 2010;90:1401–8. Gillinov AM, Banbury MK, Cosgrove DM. Hemisternotomy approach for aortic and mitral valve surgery. J Card Surg 2000;15:15–20. Chitwood WR, Elbeery JR, Chapman WH, Moran JM, Lust RL, Wooden WA, et al. Video-assisted minimally invasive mitral valve surgery: the “micro-mitral” operation. J Thorac Cardiovasc Surg 1997;113:413–4. Chitwood WR Jr, Rodriguez E, Chu MW, Hassan A, Ferguson TB, Vos PW, et al. Robotic mitral valve repairs in 300 patients: a single-center experience. J Thorac Cardiovasc Surg 2008; 136:436–41. Suri RM, Burkhart HM, Daly RC, Dearani JA, Park SJ, Sundt TM 3rd, et al. Robotic mitral valve repair for all prolapse subsets using techniques identical to open valvuloplasty: establishing the benchmark against which percutaneous interventions should be judged. J Thorac Cardiovasc Surg 2011; 142:970–9. Ramzy D, Trento A, Cheng W, De Robertis MA, Mirocha J, Ruzza A, et al. Three hundred robotic-assisted mitral valve repairs: the Cedars-Sinai experience. J Thorac Cardiovasc Surg 2014;147:228–35. Feldman T, Kar S, Rinaldi M, Fail P, Hermiller J, Smalling R, et al. Percutaneous mitral repair with the MitraClip system: safety and midterm durability in the initial EVEREST (Endovascular Valve Edge-to-Edge REpair Study) cohort. J Am Coll Cardiol 2009;54:686–94, http://dx.doi.org/10.1016/j.jacc.2009. 03.077.