- Email: [email protected]
Basis for Intervention on Functional Tricuspid Regurgitation
Basis for Intervention on Functional Tricuspid Regurgitation Shahzad G. Raja, FRCS(CTh),* and Gilles D. Dreyfus, MD, PhD† Functional tricuspid regurgitation is a complex valvular lesion. Its optimal management remains controversial in the current era as the result of uncertainties regarding accurate diagnosis, surgical indication, the appropriate surgical procedure, and the late results of surgical treatment. It is no longer regarded a benign problem and does not resolve spontaneously after correction of left-sided heart valve lesions as once believed. It carries a significant morbidity and has an adverse impact on survival. Current techniques to repair functional tricuspid regurgitation are associated with a significant degree of residual or recurrent regurgitation mainly because of failure to address all the components of this challenging entity. This review article highlights emerging concepts and advances that provide an insight into the understanding of this perplexing lesion and attempts to define the basis of intervention on functional tricuspid regurgitation. Semin Thoracic Surg 22:79-83 © 2010 Elsevier Inc. All rights reserved. Keywords: tricuspid valve, functional tricuspid regurgitation, annuloplasty Functional tricuspid regurgitation is common in patients undergoing operations for left-sided heart valve disease, with a reported prevalence between 25% and 30%.1-3 Functional tricuspid regurgitation has many causes related to dilation of the tricuspid annulus and tethering of the tricuspid valve leaflets secondary to right ventricular (RV) dysfunction.4,5 Historically, concomitant tricuspid valve repair was less commonly performed because of the observation that functional tricuspid regurgitation often improves after left-sided heart valve operations.6 Contemporary evidence, however, suggests that tricuspid repair should be considered more often given that uncorrected functional tricuspid regurgitation is associated with poor survival and functional status.1-3,7,8 As a result, the optimal management of patients with functional tricuspid regurgitation at the time of left-sided heart-valve surgery continues to evolve. Although in recent times it has been established that patients with moderate-to-severe functional tricuspid regurgitation should have concomitant tricuspid-valve repair, the management of mild functional tricuspid regurgitation at the time of left-sided heart-valve surgery remains controversial.9
*Department of Cardiothoracic Surgery, Great Ormond Street Hospital, London, United Kingdom. †Center Cardio-thoracique de Monaco, Monaco Cedex. Address reprint requests to Shahzad G. Raja, FRCS(CTh), Department of Cardiothoracic Surgery, Great Ormond Street Hospital, WC1N 3JH London, UK. E-mail: drrajashahzad@ hotmail.com
1043-0679/$-see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1053/j.semtcvs.2010.05.005
Another important issue that complicates management of functional tricuspid regurgitation is recurrent, progressive or residual regurgitation after surgical intervention using current techniques.10-14 This review article attempts to define the basis of intervention to treat functional tricuspid regurgitation and also to prevent residual or recurrent tricuspid regurgitation taking into account the emerging concepts and advances that provide an insight into the understanding of this perplexing lesion. CORRECTION OF ANNULAR DILATION AS THE BASIS FOR INTERVENTION ON FUNCTIONAL TRICUSPID REGURGITATION Contrary to the traditional view, correction of leftsided valvular disease does not automatically correct functional tricuspid regurgitation.15 Treatment of the mitral lesion alone only decreases the afterload. It does not correct tricuspid dilation, nor does it affect preload or RV function.16 Dilatation of the tricuspid annulus is progressive and may not be accompanied by tricuspid regurgitation initially, but eventually leads to it.16 The normal tricuspid valve annulus is a bimodal nonplanar structure with distinct high points located anteroposteriorly and low points located mediolaterally. It is known that with functional tricuspid regurgitation the annulus becomes larger, more planar, and circular. The flattening of the tricuspid valve annulus that occurs with tricuspid regurgitation can potentially alter the normal papillary muscle-to-leaflet and annulus relationship. With flattening of the annulus, the low points of the annulus may be 79
FUNCTIONAL TRICUSPID REGURGITATION Table 1. Impact of Tricuspid Valve Repair at the Time of Mitral Valve Repair on Progression of Tricuspid Regurgitation* Before Surgery Grade 0 Grade 1 Grade 2 Grade 3 Grade 4 Mean TR grade
Group 1 (MVR) 54 102 7 0 0 0.7 ⫾ 0.5†
After Surgery
Group 2 (MVR ⫹ TVR) 38 92 16 2 0 0.9 ⫾ 0.6†
Group 1 (MVR) 8 33 67 40 15 2.1 ⫾ 1.0‡
Group 2 (MVR ⫹ TVR) 102 41 34 1 0 0.4 ⫾ 0.6‡
MVR, mitral valve repair; TVR, tricuspid regurgitation. Reprinted with permission from Dreyfus et al,16 © 2005 Society of Thoracic Surgeons. *Measurements by transthoracic echocardiography. †P ⫽ 0.027, Mann–Whitney. ‡P ⬍ 0.001, Mann–Whitney.
stretched away from the papillary muscles, thereby increasing tethering.17 The tricuspid annulus is a component of both the tricuspid valve and the right ventricle.16 Ton-Nu et al17 suggest that it is not the RV pressure load or leftsided heart disease that influences the annular remodeling changes observed with functional tricuspid regurgitation. It is the RV dysfunction and dilation that affect those annular remodeling changes. As suggested by Ton-Nu et al,17 the RV dysfunction and tricuspid regurgitation are indeed linked, perhaps through the mechanism of annular shape. Possibly, the tricuspid annulus can be thought of as the “gear” that modulates the effects of RV remodeling on tricuspid valve function. The presence of secondary tricuspid pathology is often not appreciated, especially if severe tricuspid regurgitation is not present. Although there is no question that considerable tricuspid pathology is present when there is severe tricuspid regurgitation, considerable tricuspid pathology may also be present when the severity of tricuspid regurgitation is only mild or moderate18 because the assessment of the tricuspid valve at a given time by echocardiography is dependent upon the preload and afterload conditions of the patient, and these conditions may vary from time to time. The absence of tricuspid regurgitation or the presence of only mild tricuspid regurgitation does not mean that the tricuspid orifice is free of any abnormality, such as tricuspid annular dilation. Because the grading of tricuspid regurgitation is highly subjective, and because there is considerable variation in the severity of tricuspid regurgitation depending on RV preload, afterload, and contractility, we have proposed that a decision to perform concomitant tricuspid valve surgery at the time of left-sided heartvalve surgery in patients with less than severe tricuspid regurgitation should be determined by the tricuspid annular diameter.16 It is unlikely that patients with no 80
or trace tricuspid regurgitation will develop significant tricuspid regurgitation late after left-sided heart-valve surgery if the tricuspid annulus is not dilated at the time of the initial surgery. Conversely, it is very likely that significant tricuspid regurgitation will develop in these patients if significant tricuspid annular dilation is present and is not corrected at the time of left-sided heart-valve surgery (Table 1).16 We directly measure the size of the tricuspid annulus at the time of mitral valve surgery and repair the tricuspid valve concomitantly if the tricuspid annulus is dilated beyond 70 mm, which is twice its normal size. In our series of 311 patients, we found that 48% of our patients had such tricuspid annular dilation, even though the majority had no more than trace tricuspid regurgitation.16 Functional class at late follow-up was significantly improved in those patients who had a concomitant tricuspid valve repair compared with those who did not. Such intraoperative measurement of the tricuspid annulus size is highly reliable and reproducible, and measures the maximum tricuspid annulus in the fully relaxed, arrested heart from the anteroseptal commissure to the anteroposterior commissure.16 It should be noted that this differs from echocardiographic measurement of the tricuspid annular diameter. A typical 4-chamber echocardiographic view would measure the tricuspid annulus from the middle of the septal annulus to the middle of the anterior annulus. It has been suggested that using echocardiographic measurements, a tricuspid annulus diameter of greater than 40 mm or 21 mm/m2 measured in the 4-chamber view should indicate the need for concomitant tricuspid valve repair.19 We therefore recommend that in patients with less than severe functional tricuspid regurgitation the tricuspid annular diameter should be measured, and if this is dilated beyond 70 mm as measured directly in the operating theater
Seminars in Thoracic and Cardiovascular Surgery ● Volume 22, Number 1
FUNCTIONAL TRICUSPID REGURGITATION (from the anteroseptal to the anteroposterior commissure) or greater than 40 mm in the 4-chamber echocardiogram (from the middle of the septal annulus to the middle of the anterior annulus), then concomitant tricuspid valve repair should be performed.9,16 An important effect of timely intervention to correct tricuspid annular dilation is reverse remodeling of RV. We have demonstrated that once the annulus is dilated and, consequently, the RV function mildly impaired, the process of tricuspid regurgitation is progressive and will subsequently become clinically relevant.16 By contrast, annuloplasty to correct tricuspid dilation impacts RV function positively with same late survival rate for extremely ill patients with larger right ventricles as manifested by those without annular dilation.16 Our experience has thus prompted us to advocate “prophylactic annuloplasty”— correction of tricuspid regurgitation based on tricuspid dilation and not grade of tricuspid regurgitation—which allows more adequate treatment of a condition that typically remains indiscriminate for extended periods, but becomes a considerable challenge when clinically relevant. TACKLING OF TETHERING AS THE BASIS FOR INTERVENTION TO PREVENT RESIDUAL OR RECURRENT FUNCTIONAL TRICUSPID REGURGITATION Current treatment of functional tricuspid regurgitation consists of resizing the annulus with either ring or suture annuloplasty.20 Unfortunately, the success of tricuspid valve repair is often uncertain, especially with suture repair techniques, and results in residual, recurrent or progressive tricuspid regurgi-
tation after tricuspid valve annnuloplasty.10-14 The presence of residual or recurrent tricuspid regurgitation is associated with increased perioperative and late postoperative morbidity and mortality.11 McCarthy et al11 were the first to highlight this concept. They demonstrated that 14% of the patients had 3⫹ or 4⫹ tricuspid regurgitation 1 week after annuloplasty. In a follow-up study, the same group further elaborated the determinants of recurrent or residual functional tricuspid regurgitation after tricuspid annuloplasty.14 This study consisted of 39 patients with functional tricuspid regurgitation who had echocardiography preoperatively, early postoperatively (5 ⫾ 2 days), and ⬎1 year (20 ⫾ 6 months) after tricuspid valve annuloplasty. Detailed echocardiographic measurements were performed, including tricuspid regurgitation severity, tricuspid valve annular dimension, tricuspid valve leaflet displacement, left ventricular function, and RV function, and pressures. The authors showed that preoperative leaflet tethering height and area predicted early and midterm outcome of annuloplasty. All currently available surgical options fail to address leaflet tethering appropriately with resultant significantly high incidence of recurrent or residual tricuspid regurgitation. We divide functional tricuspid regurgitation for therapeutic purposes into 3 phases. In the first phase, dilation of the RV results in dilation of the tricuspid annulus. Tricuspid regurgitation may or may not be present, depending on the degree of annular dilation and resulting lack of leaflet coaptation.16 In the second phase, with progressive dilation of the RV and tricuspid annulus, significant tricuspid regurgitation will occur due to failure of leaflet coap-
Figure 1. Algorithm for the management of functional tricuspid regurgitation. *MV disease requiring surgery. †Preferably prosthetic annuloplasty. MV, mitral valve; PASP, pulmonary artery systolic pressure; TAD, tricuspid annulus diameter; TVR, tricuspid valve repair; TA, tricuspid annuloplasty. Seminars in Thoracic and Cardiovascular Surgery ● Volume 22, Number 1
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FUNCTIONAL TRICUSPID REGURGITATION tation.21 Finally, in the third phase, with progressive RV dilation and eccentricity, tethering of the tricuspid leaflets also occurs, in addition to annular dilation, because of the attachment of the papillary muscles of the tricuspid leaflets to the free wall of the RV.4 A tethering height of 8 mm or more, measured from the plane of the tricuspid annulus to the theoretic point of coaptation of the tricuspid valve leaflets at end-systole, has been reported to be predictive of greater than moderate functional tricuspid regurgitation.22 We recommend surgical intervention tailored to the stage of the disease (Fig. 1). In the first 2 phases, where the problem is that of tricuspid annular dilation without leaflet tethering, tricuspid annuloplasty alone gives excellent results.16 However, in the third phase where both significant annular dilation and leaflet tethering are present, annuloplasty alone is unlikely to be successful in correcting the tricuspid regurgitation, and some additional procedure to overcome the tethering effects is likely to be necessary.11 It is, however, important to emphasize that detection of tethering on 2-dimensional echocardiography can be misleading as extent of tethering is influenced by RV preload as well as function. In a patient who has been fluid off-loaded with aggressive diuretic therapy, edge-to-edge coaptation of tricuspid leaflets may underestimate the severity of tethering. We therefore suggest that a minimum of 4-mm height of coaptation of the leaflets must be demonstrated on preoperative echocardiography to effectively exclude leaflet tethering. Failure to take into account this fact during preoperative assessment of functional tricuspid regurgitation can result in suboptimal results both in the short-as well as the long-term. Until recently, suture bicuspidization23 and clover technique24 were suggested as effective strategies to address tethering. However, these repair techniques further increase leaflet tension and restrict leaflet motion and do not relieve the tethering effects of the dilated RV, which are important factors responsible for recurrent tricuspid regurgitation after ring annuloplasty.14 Tricuspid valve replacement is another valid option for dealing with severe tethering. How-
1. King RM, Schaff HV, Danielson GK, et al: Surgery for tricuspid regurgitation late after mitral valve replacement. Circulation 70:I193-I197, 1984 2. Cohen SR, Sell JE, McIntosh CL, et al: Tricuspid regurgitation in patients with acquired, chronic, pure mitral regurgitation. II. Nonoperative management, tricuspid valve annuloplasty, and tricuspid valve replacement. J Thorac Cardiovasc Surg 94:488-497, 1987
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ever, even in the current era, the procedure still has a very high immediate perioperative morbidity and mortality rate, and there is a constant risk of death (up to 3% per year) in the medium term to long-term outcome.25 To address tethering, we have recently proposed the technique of anterior tricuspid leaflet augmentation to increase the surface area of the anterior tricuspid leaflet, and by doing so increasing its surface of coaptation with the septal and posterior leaflets.26 Contrary to other techniques,23,24 our technique maintains the anatomical relationship of leaflets as well as leaflet mobility. This effectively compensates for severe leaflet tethering as leaflet coaptation is achieved with reduced leaflet tension. The use of an annuloplasty ring remains essential as tricuspid annular dilation is almost always present. This simple and cost-effective technique has shown promising early results, and long-term follow-up is awaited.26 CONCLUSIONS The management of functional tricuspid regurgitation remains a perplexing issue. However, in recent years better understanding of the pathophysiology of this complex entity has aided us in adopting a more proactive approach to deal with it. There is no question that patients with severe functional tricuspid regurgitation should have this corrected at the time of left-sided heart-valve surgery. For those with less than severe tricuspid regurgitation, the tricuspid annulus should be measured either by echocardiography or directly during left-sided heart-valve surgery, and concomitant tricuspid valve annuloplasty should be performed if the tricuspid annulus is significantly dilated irrespective of the grade of tricuspid regurgitation. Anterior tricuspid leaflet augmentation for concomitant severe tricuspid leaflet tethering should also be considered in addition to tricuspid annuloplasty to prevent residual or recurrent tricuspid regurgitation. In conclusion, adoption of a stage specific therapeutic approach with correction of tricuspid annular dilation as the basis for intervention on functional tricuspid regurgitation will achieve more gratifying short-as well as longterm outcomes.
3. Simon R, Oelert H, Borst HG, et al: Influence of mitral valve surgery on tricuspid incompetence concomitant with mitral valve disease. Circulation 62:I152-I157, 1980 4. Park YH, Song JM, Lee EY, et al: Geometric and hemodynamic determinants of functional tricuspid regurgitation: A real-time three-dimensional echocardiography study. Int J Cardiol 124:160165, 2008
5. Fukuda S, Saracino G, Matsumura Y, et al: Three-dimensional geometry of the tricuspid annulus in healthy subjects and in patients with functional tricuspid regurgitation: A realtime, three-dimensional echocardiographic study. Circulation 114:I492-I498, 2006 (suppl) 6. Braunwald NS, Ross J Jr, Morrow AG: Conservative management of tricuspid regurgitation in
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7.
8.
9.
10.
11.
patients undergoing mitral valve replacement. Circulation 35:I63-I69, 1967 (suppl) Bernal JM, Gutierrez-Morlote J, Llorca J, et al: Tricuspid valve repair: An old disease, a modern experience. Ann Thorac Surg 78:20692074, 2004 Nath J, Foster E, Heidenreich PA: Impact of tricuspid regurgitation on long-term survival. J Am Coll Cardiol 43:405-409, 2004 American College of Cardiology/American Heart Association Task Force on Practice Guidelines, Bonow RO, Carabello BA, et al: ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice guidelines (writing committee to revise the 1998 guidelines for the management of patients with valvular heart disease): Developed in collaboration with the Society of Cardiovascular Anesthesiologists: Endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. Circulation 114:e84-231, 2006 Rivera R, Duran E, Ajuria M: Carpentier’s flexible ring versus de Vega’s annuloplasty. A prospective randomized study. J Thorac Cardiovasc Surg 89:196-203, 1985 McCarthy PM, Bhudia SK, Rajeswaran J, et al: Tricuspid valve repair: Durability and risk factors for failure. J Thorac Cardiovasc Surg 127: 674-685, 2004
12. Fukuda S, Song JM, Gillinov AM, et al: Tricuspid valve tethering predicts residual tricuspid regurgitation after tricuspid annuloplasty. Circulation 111:975-979, 2005 13. Matsunaga A, Duran CM: Progression of tricuspid regurgitation after repaired functional ischemic mitral regurgitation. Circulation 112:I453I457, 2005 14. Fukuda S, Gillinov AM, McCarthy PM, et al: Determinants of recurrent or residual functional tricuspid regurgitation after tricuspid annuloplasty. Circulation 114:I582-I587, 2006 (suppl) 15. Shiran A, Sagie A: Tricuspid regurgitation in mitral valve disease incidence, prognostic implications, mechanism, and management. J Am Coll Cardiol 53:401-408, 2009 16. Dreyfus GD, Corbi PJ, Chan KMJ, et al: Secondary tricuspid regurgitation or dilatation: Which should be the criteria for surgical repair? Ann Thorac Surg 79:127-132, 2005 17. Ton-Nu TT, Levine RA, Handschumacher MD, et al: Geometric determinants of functional tricuspid regurgitation: Insights from 3-dimensional echocardiography. Circulation 114:143-149, 2006 18. Porter A, Shapira Y, Wurzel M, et al: Tricuspid regurgitation late after mitral valve replacement: Clinical and echocardiographic evaluation. J Heart Valve Dis 8:57-62, 1999 19. Colombo T, Russo C, Ciliberto GR, et al: Tricuspid regurgitation secondary to mitral valve disease: Tricuspid annular function as guide to tri-
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20.
21.
22.
23.
24.
25.
26.
cuspid valve repair. Cardiovasc Surg 9:369-377, 2001 Raja SG, Dreyfus GD: Surgery for functional tricuspid regurgitation: Current techniques, outcomes and emerging concepts. Expert Rev Cardiovasc Ther 7:73-84, 2009 Tei C, Pilgrim JP, Shah P, et al: The tricuspid valve annulus: Study of size and motion in normal subjects and in patients with tricuspid regurgitation. Circulation 66:665-671, 1982 Kim HK, Kim YJ, Park JS, et al: Determinants of the severity of functional tricuspid regurgitation. Am J Cardiol 98:236-242, 2006 De Bonis M, Lapenna E, La Canna G, et al: A novel technique for correction of severe tricuspid valve regurgitation due to complex lesions. Eur J Cardiothorac Surg 25:760-765, 2004 Ghanta RK, Chen R, Narayanasamy N, et al: Suture bicuspidization of the tricuspid valve versus ring annuloplasty for repair of functional tricuspid regurgitation: Midterm results of 237 patients. J Thorac Cardiovasc Surg 133: 117-126, 2007 Filsoufi F, Anyanwu AC, Salzberg SP, et al: Long-term outcomes of tricuspid valve replacement in the current era. Ann Thorac Surg 80:845-850, 2005 Dreyfus GD, Raja SG, John CKM: Tricuspid leaflet augmentation to address severe tethering in functional tricuspid regurgitation. Eur J Cardiothorac Surg 34:908-910, 2008
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*Department of Cardiothoracic Surgery, Great Ormond Street Hospital, London, United Kingdom. †Center Cardio-thoracique de Monaco, Monaco Cedex. Address reprint requests to Shahzad G. Raja, FRCS(CTh), Department of Cardiothoracic Surgery, Great Ormond Street Hospital, WC1N 3JH London, UK. E-mail: drrajashahzad@ hotmail.com
1043-0679/$-see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1053/j.semtcvs.2010.05.005
Another important issue that complicates management of functional tricuspid regurgitation is recurrent, progressive or residual regurgitation after surgical intervention using current techniques.10-14 This review article attempts to define the basis of intervention to treat functional tricuspid regurgitation and also to prevent residual or recurrent tricuspid regurgitation taking into account the emerging concepts and advances that provide an insight into the understanding of this perplexing lesion. CORRECTION OF ANNULAR DILATION AS THE BASIS FOR INTERVENTION ON FUNCTIONAL TRICUSPID REGURGITATION Contrary to the traditional view, correction of leftsided valvular disease does not automatically correct functional tricuspid regurgitation.15 Treatment of the mitral lesion alone only decreases the afterload. It does not correct tricuspid dilation, nor does it affect preload or RV function.16 Dilatation of the tricuspid annulus is progressive and may not be accompanied by tricuspid regurgitation initially, but eventually leads to it.16 The normal tricuspid valve annulus is a bimodal nonplanar structure with distinct high points located anteroposteriorly and low points located mediolaterally. It is known that with functional tricuspid regurgitation the annulus becomes larger, more planar, and circular. The flattening of the tricuspid valve annulus that occurs with tricuspid regurgitation can potentially alter the normal papillary muscle-to-leaflet and annulus relationship. With flattening of the annulus, the low points of the annulus may be 79
FUNCTIONAL TRICUSPID REGURGITATION Table 1. Impact of Tricuspid Valve Repair at the Time of Mitral Valve Repair on Progression of Tricuspid Regurgitation* Before Surgery Grade 0 Grade 1 Grade 2 Grade 3 Grade 4 Mean TR grade
Group 1 (MVR) 54 102 7 0 0 0.7 ⫾ 0.5†
After Surgery
Group 2 (MVR ⫹ TVR) 38 92 16 2 0 0.9 ⫾ 0.6†
Group 1 (MVR) 8 33 67 40 15 2.1 ⫾ 1.0‡
Group 2 (MVR ⫹ TVR) 102 41 34 1 0 0.4 ⫾ 0.6‡
MVR, mitral valve repair; TVR, tricuspid regurgitation. Reprinted with permission from Dreyfus et al,16 © 2005 Society of Thoracic Surgeons. *Measurements by transthoracic echocardiography. †P ⫽ 0.027, Mann–Whitney. ‡P ⬍ 0.001, Mann–Whitney.
stretched away from the papillary muscles, thereby increasing tethering.17 The tricuspid annulus is a component of both the tricuspid valve and the right ventricle.16 Ton-Nu et al17 suggest that it is not the RV pressure load or leftsided heart disease that influences the annular remodeling changes observed with functional tricuspid regurgitation. It is the RV dysfunction and dilation that affect those annular remodeling changes. As suggested by Ton-Nu et al,17 the RV dysfunction and tricuspid regurgitation are indeed linked, perhaps through the mechanism of annular shape. Possibly, the tricuspid annulus can be thought of as the “gear” that modulates the effects of RV remodeling on tricuspid valve function. The presence of secondary tricuspid pathology is often not appreciated, especially if severe tricuspid regurgitation is not present. Although there is no question that considerable tricuspid pathology is present when there is severe tricuspid regurgitation, considerable tricuspid pathology may also be present when the severity of tricuspid regurgitation is only mild or moderate18 because the assessment of the tricuspid valve at a given time by echocardiography is dependent upon the preload and afterload conditions of the patient, and these conditions may vary from time to time. The absence of tricuspid regurgitation or the presence of only mild tricuspid regurgitation does not mean that the tricuspid orifice is free of any abnormality, such as tricuspid annular dilation. Because the grading of tricuspid regurgitation is highly subjective, and because there is considerable variation in the severity of tricuspid regurgitation depending on RV preload, afterload, and contractility, we have proposed that a decision to perform concomitant tricuspid valve surgery at the time of left-sided heartvalve surgery in patients with less than severe tricuspid regurgitation should be determined by the tricuspid annular diameter.16 It is unlikely that patients with no 80
or trace tricuspid regurgitation will develop significant tricuspid regurgitation late after left-sided heart-valve surgery if the tricuspid annulus is not dilated at the time of the initial surgery. Conversely, it is very likely that significant tricuspid regurgitation will develop in these patients if significant tricuspid annular dilation is present and is not corrected at the time of left-sided heart-valve surgery (Table 1).16 We directly measure the size of the tricuspid annulus at the time of mitral valve surgery and repair the tricuspid valve concomitantly if the tricuspid annulus is dilated beyond 70 mm, which is twice its normal size. In our series of 311 patients, we found that 48% of our patients had such tricuspid annular dilation, even though the majority had no more than trace tricuspid regurgitation.16 Functional class at late follow-up was significantly improved in those patients who had a concomitant tricuspid valve repair compared with those who did not. Such intraoperative measurement of the tricuspid annulus size is highly reliable and reproducible, and measures the maximum tricuspid annulus in the fully relaxed, arrested heart from the anteroseptal commissure to the anteroposterior commissure.16 It should be noted that this differs from echocardiographic measurement of the tricuspid annular diameter. A typical 4-chamber echocardiographic view would measure the tricuspid annulus from the middle of the septal annulus to the middle of the anterior annulus. It has been suggested that using echocardiographic measurements, a tricuspid annulus diameter of greater than 40 mm or 21 mm/m2 measured in the 4-chamber view should indicate the need for concomitant tricuspid valve repair.19 We therefore recommend that in patients with less than severe functional tricuspid regurgitation the tricuspid annular diameter should be measured, and if this is dilated beyond 70 mm as measured directly in the operating theater
Seminars in Thoracic and Cardiovascular Surgery ● Volume 22, Number 1
FUNCTIONAL TRICUSPID REGURGITATION (from the anteroseptal to the anteroposterior commissure) or greater than 40 mm in the 4-chamber echocardiogram (from the middle of the septal annulus to the middle of the anterior annulus), then concomitant tricuspid valve repair should be performed.9,16 An important effect of timely intervention to correct tricuspid annular dilation is reverse remodeling of RV. We have demonstrated that once the annulus is dilated and, consequently, the RV function mildly impaired, the process of tricuspid regurgitation is progressive and will subsequently become clinically relevant.16 By contrast, annuloplasty to correct tricuspid dilation impacts RV function positively with same late survival rate for extremely ill patients with larger right ventricles as manifested by those without annular dilation.16 Our experience has thus prompted us to advocate “prophylactic annuloplasty”— correction of tricuspid regurgitation based on tricuspid dilation and not grade of tricuspid regurgitation—which allows more adequate treatment of a condition that typically remains indiscriminate for extended periods, but becomes a considerable challenge when clinically relevant. TACKLING OF TETHERING AS THE BASIS FOR INTERVENTION TO PREVENT RESIDUAL OR RECURRENT FUNCTIONAL TRICUSPID REGURGITATION Current treatment of functional tricuspid regurgitation consists of resizing the annulus with either ring or suture annuloplasty.20 Unfortunately, the success of tricuspid valve repair is often uncertain, especially with suture repair techniques, and results in residual, recurrent or progressive tricuspid regurgi-
tation after tricuspid valve annnuloplasty.10-14 The presence of residual or recurrent tricuspid regurgitation is associated with increased perioperative and late postoperative morbidity and mortality.11 McCarthy et al11 were the first to highlight this concept. They demonstrated that 14% of the patients had 3⫹ or 4⫹ tricuspid regurgitation 1 week after annuloplasty. In a follow-up study, the same group further elaborated the determinants of recurrent or residual functional tricuspid regurgitation after tricuspid annuloplasty.14 This study consisted of 39 patients with functional tricuspid regurgitation who had echocardiography preoperatively, early postoperatively (5 ⫾ 2 days), and ⬎1 year (20 ⫾ 6 months) after tricuspid valve annuloplasty. Detailed echocardiographic measurements were performed, including tricuspid regurgitation severity, tricuspid valve annular dimension, tricuspid valve leaflet displacement, left ventricular function, and RV function, and pressures. The authors showed that preoperative leaflet tethering height and area predicted early and midterm outcome of annuloplasty. All currently available surgical options fail to address leaflet tethering appropriately with resultant significantly high incidence of recurrent or residual tricuspid regurgitation. We divide functional tricuspid regurgitation for therapeutic purposes into 3 phases. In the first phase, dilation of the RV results in dilation of the tricuspid annulus. Tricuspid regurgitation may or may not be present, depending on the degree of annular dilation and resulting lack of leaflet coaptation.16 In the second phase, with progressive dilation of the RV and tricuspid annulus, significant tricuspid regurgitation will occur due to failure of leaflet coap-
Figure 1. Algorithm for the management of functional tricuspid regurgitation. *MV disease requiring surgery. †Preferably prosthetic annuloplasty. MV, mitral valve; PASP, pulmonary artery systolic pressure; TAD, tricuspid annulus diameter; TVR, tricuspid valve repair; TA, tricuspid annuloplasty. Seminars in Thoracic and Cardiovascular Surgery ● Volume 22, Number 1
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FUNCTIONAL TRICUSPID REGURGITATION tation.21 Finally, in the third phase, with progressive RV dilation and eccentricity, tethering of the tricuspid leaflets also occurs, in addition to annular dilation, because of the attachment of the papillary muscles of the tricuspid leaflets to the free wall of the RV.4 A tethering height of 8 mm or more, measured from the plane of the tricuspid annulus to the theoretic point of coaptation of the tricuspid valve leaflets at end-systole, has been reported to be predictive of greater than moderate functional tricuspid regurgitation.22 We recommend surgical intervention tailored to the stage of the disease (Fig. 1). In the first 2 phases, where the problem is that of tricuspid annular dilation without leaflet tethering, tricuspid annuloplasty alone gives excellent results.16 However, in the third phase where both significant annular dilation and leaflet tethering are present, annuloplasty alone is unlikely to be successful in correcting the tricuspid regurgitation, and some additional procedure to overcome the tethering effects is likely to be necessary.11 It is, however, important to emphasize that detection of tethering on 2-dimensional echocardiography can be misleading as extent of tethering is influenced by RV preload as well as function. In a patient who has been fluid off-loaded with aggressive diuretic therapy, edge-to-edge coaptation of tricuspid leaflets may underestimate the severity of tethering. We therefore suggest that a minimum of 4-mm height of coaptation of the leaflets must be demonstrated on preoperative echocardiography to effectively exclude leaflet tethering. Failure to take into account this fact during preoperative assessment of functional tricuspid regurgitation can result in suboptimal results both in the short-as well as the long-term. Until recently, suture bicuspidization23 and clover technique24 were suggested as effective strategies to address tethering. However, these repair techniques further increase leaflet tension and restrict leaflet motion and do not relieve the tethering effects of the dilated RV, which are important factors responsible for recurrent tricuspid regurgitation after ring annuloplasty.14 Tricuspid valve replacement is another valid option for dealing with severe tethering. How-
1. King RM, Schaff HV, Danielson GK, et al: Surgery for tricuspid regurgitation late after mitral valve replacement. Circulation 70:I193-I197, 1984 2. Cohen SR, Sell JE, McIntosh CL, et al: Tricuspid regurgitation in patients with acquired, chronic, pure mitral regurgitation. II. Nonoperative management, tricuspid valve annuloplasty, and tricuspid valve replacement. J Thorac Cardiovasc Surg 94:488-497, 1987
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ever, even in the current era, the procedure still has a very high immediate perioperative morbidity and mortality rate, and there is a constant risk of death (up to 3% per year) in the medium term to long-term outcome.25 To address tethering, we have recently proposed the technique of anterior tricuspid leaflet augmentation to increase the surface area of the anterior tricuspid leaflet, and by doing so increasing its surface of coaptation with the septal and posterior leaflets.26 Contrary to other techniques,23,24 our technique maintains the anatomical relationship of leaflets as well as leaflet mobility. This effectively compensates for severe leaflet tethering as leaflet coaptation is achieved with reduced leaflet tension. The use of an annuloplasty ring remains essential as tricuspid annular dilation is almost always present. This simple and cost-effective technique has shown promising early results, and long-term follow-up is awaited.26 CONCLUSIONS The management of functional tricuspid regurgitation remains a perplexing issue. However, in recent years better understanding of the pathophysiology of this complex entity has aided us in adopting a more proactive approach to deal with it. There is no question that patients with severe functional tricuspid regurgitation should have this corrected at the time of left-sided heart-valve surgery. For those with less than severe tricuspid regurgitation, the tricuspid annulus should be measured either by echocardiography or directly during left-sided heart-valve surgery, and concomitant tricuspid valve annuloplasty should be performed if the tricuspid annulus is significantly dilated irrespective of the grade of tricuspid regurgitation. Anterior tricuspid leaflet augmentation for concomitant severe tricuspid leaflet tethering should also be considered in addition to tricuspid annuloplasty to prevent residual or recurrent tricuspid regurgitation. In conclusion, adoption of a stage specific therapeutic approach with correction of tricuspid annular dilation as the basis for intervention on functional tricuspid regurgitation will achieve more gratifying short-as well as longterm outcomes.
3. Simon R, Oelert H, Borst HG, et al: Influence of mitral valve surgery on tricuspid incompetence concomitant with mitral valve disease. Circulation 62:I152-I157, 1980 4. Park YH, Song JM, Lee EY, et al: Geometric and hemodynamic determinants of functional tricuspid regurgitation: A real-time three-dimensional echocardiography study. Int J Cardiol 124:160165, 2008
5. Fukuda S, Saracino G, Matsumura Y, et al: Three-dimensional geometry of the tricuspid annulus in healthy subjects and in patients with functional tricuspid regurgitation: A realtime, three-dimensional echocardiographic study. Circulation 114:I492-I498, 2006 (suppl) 6. Braunwald NS, Ross J Jr, Morrow AG: Conservative management of tricuspid regurgitation in
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7.
8.
9.
10.
11.
patients undergoing mitral valve replacement. Circulation 35:I63-I69, 1967 (suppl) Bernal JM, Gutierrez-Morlote J, Llorca J, et al: Tricuspid valve repair: An old disease, a modern experience. Ann Thorac Surg 78:20692074, 2004 Nath J, Foster E, Heidenreich PA: Impact of tricuspid regurgitation on long-term survival. J Am Coll Cardiol 43:405-409, 2004 American College of Cardiology/American Heart Association Task Force on Practice Guidelines, Bonow RO, Carabello BA, et al: ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice guidelines (writing committee to revise the 1998 guidelines for the management of patients with valvular heart disease): Developed in collaboration with the Society of Cardiovascular Anesthesiologists: Endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. Circulation 114:e84-231, 2006 Rivera R, Duran E, Ajuria M: Carpentier’s flexible ring versus de Vega’s annuloplasty. A prospective randomized study. J Thorac Cardiovasc Surg 89:196-203, 1985 McCarthy PM, Bhudia SK, Rajeswaran J, et al: Tricuspid valve repair: Durability and risk factors for failure. J Thorac Cardiovasc Surg 127: 674-685, 2004
12. Fukuda S, Song JM, Gillinov AM, et al: Tricuspid valve tethering predicts residual tricuspid regurgitation after tricuspid annuloplasty. Circulation 111:975-979, 2005 13. Matsunaga A, Duran CM: Progression of tricuspid regurgitation after repaired functional ischemic mitral regurgitation. Circulation 112:I453I457, 2005 14. Fukuda S, Gillinov AM, McCarthy PM, et al: Determinants of recurrent or residual functional tricuspid regurgitation after tricuspid annuloplasty. Circulation 114:I582-I587, 2006 (suppl) 15. Shiran A, Sagie A: Tricuspid regurgitation in mitral valve disease incidence, prognostic implications, mechanism, and management. J Am Coll Cardiol 53:401-408, 2009 16. Dreyfus GD, Corbi PJ, Chan KMJ, et al: Secondary tricuspid regurgitation or dilatation: Which should be the criteria for surgical repair? Ann Thorac Surg 79:127-132, 2005 17. Ton-Nu TT, Levine RA, Handschumacher MD, et al: Geometric determinants of functional tricuspid regurgitation: Insights from 3-dimensional echocardiography. Circulation 114:143-149, 2006 18. Porter A, Shapira Y, Wurzel M, et al: Tricuspid regurgitation late after mitral valve replacement: Clinical and echocardiographic evaluation. J Heart Valve Dis 8:57-62, 1999 19. Colombo T, Russo C, Ciliberto GR, et al: Tricuspid regurgitation secondary to mitral valve disease: Tricuspid annular function as guide to tri-
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20.
21.
22.
23.
24.
25.
26.
cuspid valve repair. Cardiovasc Surg 9:369-377, 2001 Raja SG, Dreyfus GD: Surgery for functional tricuspid regurgitation: Current techniques, outcomes and emerging concepts. Expert Rev Cardiovasc Ther 7:73-84, 2009 Tei C, Pilgrim JP, Shah P, et al: The tricuspid valve annulus: Study of size and motion in normal subjects and in patients with tricuspid regurgitation. Circulation 66:665-671, 1982 Kim HK, Kim YJ, Park JS, et al: Determinants of the severity of functional tricuspid regurgitation. Am J Cardiol 98:236-242, 2006 De Bonis M, Lapenna E, La Canna G, et al: A novel technique for correction of severe tricuspid valve regurgitation due to complex lesions. Eur J Cardiothorac Surg 25:760-765, 2004 Ghanta RK, Chen R, Narayanasamy N, et al: Suture bicuspidization of the tricuspid valve versus ring annuloplasty for repair of functional tricuspid regurgitation: Midterm results of 237 patients. J Thorac Cardiovasc Surg 133: 117-126, 2007 Filsoufi F, Anyanwu AC, Salzberg SP, et al: Long-term outcomes of tricuspid valve replacement in the current era. Ann Thorac Surg 80:845-850, 2005 Dreyfus GD, Raja SG, John CKM: Tricuspid leaflet augmentation to address severe tethering in functional tricuspid regurgitation. Eur J Cardiothorac Surg 34:908-910, 2008
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