Targeted triangular resection for repair of degenerative mitral valve disease

Central MessageTriangular resection is a versatile option for mitral valve repair in segmental posterior leaflet prolapse. Several techniques can be employed to achieve excellent repair quality and durability.See Commentary on page 53. Triangular resection is a versatile option for mitral valve repair in segmental posterior leaflet prolapse. Several techniques can be employed to achieve excellent repair quality and durability. See Commentary on page 53. For patients with primary mitral regurgitation (MR) secondary to degenerative mitral valve disease, mitral valve repair is the gold standard therapy. The benefits of mitral valve repair in patients with degenerative disease are well established. In addition to superior survival, a complete mitral valve repair decreases risks of thromboembolism, endocarditis, anticoagulant-related hemorrhage, and reintervention relative to valve replacement.1David T.E. David C.M. Tsang W. Lafreniere-Roula M. Manlhiot C. Long-term results of mitral valve repair for regurgitation due to leaflet prolapse.J Am Coll Cardiol. 2019; 74: 1044-1053Crossref PubMed Scopus (54) Google Scholar, 2Gillinov A.M. Blackstone E.H. Nowicki E.R. Slisatkorn W. Al-Dossari G. Johnston D.R. et al.Valve repair versus valve replacement for degenerative mitral valve disease.J Thorac Cardiovasc Surg. 2008; 135 (893): 885-893Abstract Full Text Full Text PDF PubMed Scopus (180) Google Scholar, 3Suri R.M. Schaff H.V. Dearani J.A. Sundt T.M. Daly R.C. Mullany C.J. et al.Survival advantage and improved durability of mitral repair for leaflet prolapse subsets in the current era.Ann Thorac Surg. 2006; 82: 819-826Abstract Full Text Full Text PDF PubMed Scopus (333) Google Scholar, 4Braunberger E. Deloche A. Berrebi A. Abdallah F. Celestin J.A. Meimoun P. et al.Very long-term results (more than 20 years) of valve repair with Carpentier's techniques in nonrheumatic mitral valve insufficiency.Circulation. 2001; 104: I8-I11Crossref PubMed Google Scholar Many mitral valve repair techniques are available to the surgeon, with varying degrees of complexity, that should result in a successful valve repair >90% of the time. Of these techniques, we are going to focus this discussion on one of the most practical: the triangular resection. We will begin with the initial considerations of every valve repair and move on to the specific techniques and nuances of performing a mitral valve repair using a targeted triangular resection. Before undertaking any attempt at mitral valve repair, careful examination of the intraoperative transesophageal echocardiogram (TEE) is essential. The exact mechanism of MR can be determined by careful examination of both 2-dimensional and 3-dimensional imaging. Sites of prolapse/flail and degree of excess leaflet tissue should be evident. With the addition of color Doppler, jet volume and direction can confirm the major lesion present and help uncover any additional sites of regurgitation that may need to be addressed, such as prominent indentations between segments. The other important function performed by intraoperative TEE is the determination of the risk of postrepair systolic anterior motion (SAM) of the anterior leaflet. Basal septal thickness ≥15 mm, a narrow left ventricular outflow tract (septum to coaptation point <25 mm, aortomitral angle <120°), a small ventricle (end diastolic diameter <45 mm), and posterior leaflet length ≥15 mm all have been shown to predict SAM following mitral valve repair.5Varghese R. Itagaki S. Anyanwu A.C. Trigo P. Fischer G. Adams D.H. Predicting systolic anterior motion after mitral valve reconstruction: using intraoperative transoesophageal echocardiography to identify those at greatest risk.Eur J Cardiothorac Surg. 2014; 45: 132-137Crossref PubMed Scopus (70) Google Scholar If SAM is present before repair, we favor planning for an extensive resection-based repair. With proper planning and TEE assessment, the proper repair techniques can be chosen and the risk of postoperative SAM mitigated. The first step to any mitral valve repair is obtaining the necessary valve exposure. Exposure maneuvers will differ somewhat depending on the initial operative approach. In a sternotomy-based approach, after entering into the pericardium, stay sutures are placed on the right side only, allowing the heart to roll left. Standard aortobicaval cannulation is typically performed, although single right atrial venous cannulation with a multistage cannula can be used as well. Certain techniques can further enhance exposure. These include freeing up the tissue surrounding the superior vena cava, opening the oblique sinus, and/or placing a snare around the inferior vena cava cannula and distracting it inferiorly under mild tension. After the heart is arrested, we prefer a left atriotomy, although in certain deep or obese patients, a trans-septal approach may be preferred. If a transseptal approach is inadequate, the incision can be carried over the dome of the left atrium. This provides excellent exposure, although it predisposes to postoperative rhythm disturbances due to invariably dividing the artery to the sinoatrial node. In the case of right thoracic approaches to the mitral valve, the direct line of sight along with the transthoracic left atrial retractor almost always results in excellent exposure. Whichever approach is used, it is worth spending extra minutes optimizing valve exposure, as this will directly affect the surgeon's ability to inspect/assess the valve, as well as carry out the necessary repair. In sternotomy approaches, it is our practice to first place annuloplasty sutures. This will enhance exposure and allow a more complete initial valve inspection. If required, placing the sutures under slight tension will elevate the valve and bring it closer to the surgeon, enhancing exposure/access and potentially "unfurling" a compressed valve. This can also apply to nonsternotomy approaches when using interrupted annuloplasty sutures, although manipulation of the transthoracic left atrial retractor is generally all that is needed to optimize exposure, given the direct line of sight. Once annuloplasty sutures are placed, a comprehensive valve assessment can be performed, with the site of valve prolapse identified and quantified. Keeping in mind the findings of the intraoperative TEE, the surgeon systematically inspects each valve segment, identifying the segment(s) of abnormal valve. It can be useful to identify a normal valve segment as a reference point, used to judge relative differences in segment height, thickness, and overall tissue redundancy. This is a crucial component of planning the mitral valve repair, and also an important crossroads. Once the valve has been inspected, we can classify it as simple or complex. In agreement with contemporary guidelines, disease of >1 posterior segment, anterior leaflet disease, or bileaflet disease is classified as complex, while single segment prolapse or flail of the posterior leaflet is considered simple.6Otto C.M. Nishimura R.A. Bonow R.O. Carabello B.A. Erwin J.P. Gentile F. et al.2020 ACC/AHA guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association joint committee on clinical practice guidelines.Circulation. 2021; 143: e72-e227PubMed Google Scholar A targeted triangular resection for mitral valve repair is best suited for a "simple" valve lesion. Complex valve lesions typically require a more extensive repair utilizing advanced techniques, alone or in combination.7Suri R.M. Taggarse A. Burkhart H.M. Daly R.C. Mauermann W. Nishimura R.A. et al.Robotic mitral valve repair for simple and complex degenerative disease: midterm clinical and echocardiographic quality outcomes.Circulation. 2015; 132: 1961-1968Crossref PubMed Scopus (63) Google Scholar If a simple valve lesion is identified, a targeted triangular resection is an excellent technique for mitral valve repair.8Chemtob R.A. Wierup P. Mick S. Gillinov M. Choosing the "Best" surgical techniques for mitral valve repair: lessons from the literature.J Card Surg. 2019; 34: 717-727Crossref PubMed Scopus (8) Google Scholar A properly performed triangular resection will be targeted toward the specific area of leaflet pathology, will decrease both leaflet height and volume, and will result in a tension-free repair.9Rimsukcharoenchai C. Pandis D. El-Eshmawi A. Anyanwu A.C. Adams D.H. Complex mitral valve regurgitation: surgical evaluation, approach and repair techniques.J Vis Surg. 2021; 7: 15Crossref Google Scholar Depending on the extent of leaflet disease, these resections may be small, more extensive, or even asymmetric. In all cases, the boundaries of the abnormal valve segment are first identified along with adjacent normal chords. This technique can be employed in segmental prolapse of any of P1, P2, or P3. However, if the prolapsing segment approaches the commissural region, alternative or adjunctive techniques will likely be required.8Chemtob R.A. Wierup P. Mick S. Gillinov M. Choosing the "Best" surgical techniques for mitral valve repair: lessons from the literature.J Card Surg. 2019; 34: 717-727Crossref PubMed Scopus (8) Google Scholar Targeted small triangular resection of the anterior leaflet has been described, and reported with success.10Saunders P.C. Grossi E.A. Schwartz C.F. Grau J.B. Ribakove G.H. Culliford A.T. et al.Anterior leaflet resection of the mitral valve.Semin Thorac Cardiovasc Surg. 2004; 16: 188-193Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar, 11Gazoni L.M. Fedoruk L.M. Kern J.A. Dent J.M. Reece T.B. Tribble C.G. et al.A simplified approach to degenerative disease: triangular resections of the mitral valve.Ann Thorac Surg. 2007; 83: 1658-1664Abstract Full Text Full Text PDF PubMed Scopus (44) Google Scholar, 12Suri R.M. Orszulak T.A. Triangular resection for repair of mitral regurgitation due to degenerative disease.Oper Tech Thorac Cardiovasc Surg. 2005; 10: 194-199Abstract Full Text Full Text PDF Scopus (37) Google Scholar However, it is our opinion that anterior leaflet pathology is better addressed with chordal-based repair techniques.7Suri R.M. Taggarse A. Burkhart H.M. Daly R.C. Mauermann W. Nishimura R.A. et al.Robotic mitral valve repair for simple and complex degenerative disease: midterm clinical and echocardiographic quality outcomes.Circulation. 2015; 132: 1961-1968Crossref PubMed Scopus (63) Google Scholar,8Chemtob R.A. Wierup P. Mick S. Gillinov M. Choosing the "Best" surgical techniques for mitral valve repair: lessons from the literature.J Card Surg. 2019; 34: 717-727Crossref PubMed Scopus (8) Google Scholar,13Schaff H.V. Nguyen A. Contemporary techniques for mitral valve repair-the Mayo Clinic experience.Indian J Thorac Cardiovasc Surg. 2020; 36: 18-26Crossref PubMed Scopus (2) Google Scholar,14Gillinov M. Burns D.J.P. Wierup P. The 10 commandments for mitral valve repair.Innovations (Phila). 2020; 15: 4-10Crossref PubMed Scopus (5) Google Scholar This technique is best used for segmental posterior prolapse without grossly excessive leaflet tissue or for an isolated small flail segment secondary to chordal rupture in fibroelastic deficiency. Traditionally, this has been described as being when the free margin of the diseased segment is approximately one-third or less of the total segment length. The boundaries of the abnormal segment are identified, and the adjacent normal chords are isolated by placing stay sutures around the chords. This defines the boundaries of abnormal tissue and elevates the diseased segment for subsequent resection and reconstruction. A small symmetric triangular resection is performed. The depth of the resection, the apex of the triangle, should be slightly longer than the base of the triangular resection at the free edge. The depth of the resection will likely not reach the annulus in this method.9Rimsukcharoenchai C. Pandis D. El-Eshmawi A. Anyanwu A.C. Adams D.H. Complex mitral valve regurgitation: surgical evaluation, approach and repair techniques.J Vis Surg. 2021; 7: 15Crossref Google Scholar,11Gazoni L.M. Fedoruk L.M. Kern J.A. Dent J.M. Reece T.B. Tribble C.G. et al.A simplified approach to degenerative disease: triangular resections of the mitral valve.Ann Thorac Surg. 2007; 83: 1658-1664Abstract Full Text Full Text PDF PubMed Scopus (44) Google Scholar The lateral margins of the resection may be slightly scalloped to ensure a tension free reconstruction when the leaflet edges are reapproximated.12Suri R.M. Orszulak T.A. Triangular resection for repair of mitral regurgitation due to degenerative disease.Oper Tech Thorac Cardiovasc Surg. 2005; 10: 194-199Abstract Full Text Full Text PDF Scopus (37) Google Scholar Once the resection is completed, the free margins at the base of the resection (the leaflet free edge) are reapproximated, and the defect is closed with interrupted or running polypropylene suture. The repair is completed with the implantation of the annuloplasty prosthetic (Figure 1). When excessive leaflet tissue is present in a segmental posterior prolapse, a more extensive triangular resection may be required. This is done to ensure that both the volume and height of the leaflet are reduced, providing a competent valve and avoiding SAM.9Rimsukcharoenchai C. Pandis D. El-Eshmawi A. Anyanwu A.C. Adams D.H. Complex mitral valve regurgitation: surgical evaluation, approach and repair techniques.J Vis Surg. 2021; 7: 15Crossref Google Scholar The same initial steps apply: identify the extent of the leaflet disease, then identify and isolate the adjacent normal chordae. The triangular resection will necessarily be wider and deeper toward the annulus to adequately remove/reduce the abnormal tissue. Reconstruction of the posterior leaflet takes place as previously described, using running or interrupted polypropylene suture (Figure 2, Video 1). With all extensive triangular resections, care must be taken to not remove too much leaflet tissue. Excessive tissue removal will create tension on the reconstructed leaflet. This will have the effect of either tethering/restricting the posterior leaflet, or creating a shallow and stiff posterior "shelf," both leading to inadequate leaflet coaptation.12Suri R.M. Orszulak T.A. Triangular resection for repair of mitral regurgitation due to degenerative disease.Oper Tech Thorac Cardiovasc Surg. 2005; 10: 194-199Abstract Full Text Full Text PDF Scopus (37) Google Scholar Ultimately, this can lead to suboptimal operative results; residual MR may be present which, along with inadequate coaptation, can lead to poorer repair durability. The best way to manage this problem is, of course, to prevent it. Before resection, the surgeon can estimate the end result by approximating the adjacent normal chordae, seeing how the reconstruction will come together. If the leaflet is poorly mobile, excessively flattened, or distorting adjacent segments, then too much tissue is going to be removed. If faced with this result after resection, this would be best addressed by converting to the more extensive sliding plasty-based repair. Judgment is key here, and it is better to err on the side of removing less tissue.Figure 2Extensive triangular resection for advanced segmental degenerative disease. A, Intraoperative transesophageal echocardiogram demonstrating the flail segment. B, Performing the triangular resection. C, Performing the leaflet reconstruction using interrupted polypropylene sutures. D, Completed repair without residual regurgitation or systolic anterior motion.View Large Image Figure ViewerDownload Hi-res image Download (PPT) In certain cases of excessive posterior leaflet tissue, an extensive resection may reduce the volume of tissue but inadequately reduce the leaflet height, leading to postrepair SAM if not addressed. In these cases, we favor a ventricularization technique to reduce the height of the reconstructed posterior leaflet.15Suri R.M. Burkhart H.M. Schaff H.V. A novel method of leaflet reconstruction after triangular resection for posterior mitral valve prolapse.Ann Thorac Surg. 2010; 89: e53-e56Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar In this technique, the free edges of the resection are not simply reapproximated. Rather, the free edges at the base of the resection are folded onto their respective ventricular aspects in order to decrease the height of the reconstructed free edge. Following the resection, each end of a double armed suture is placed from the atrial to the ventricular side through the respective free edge at the resection base. Each needle is then brought back up through the resected edge of its respective side posteriorly, toward the annulus.8Chemtob R.A. Wierup P. Mick S. Gillinov M. Choosing the "Best" surgical techniques for mitral valve repair: lessons from the literature.J Card Surg. 2019; 34: 717-727Crossref PubMed Scopus (8) Google Scholar,16Javadikasgari H. Suri R.M. Mihaljevic T. Mick S. Gillinov A.M. Technical aspects of robotic posterior mitral valve leaflet repair.Ann Cardiothorac Surg. 2016; 5: 577-581Crossref PubMed Scopus (3) Google Scholar When this suture is tied, it buries or "ventricularizes" the leading edge, thereby decreasing the height of the posterior leaflet (Figure 3, Video 2). This technique not only reduces leaflet height but also allows the equalization of an asymmetric resection if required. Following completion of the initial ventricularization, the remaining suture ends are used to complete a standard 2-layer closure, completing the leaflet reconstruction. As always, the repair is completed with the implantation of an annuloplasty prosthetic.Figure 3Extensive triangular resection with leaflet ventricularization. A, Ventricularizing the leaflet free edge as appropriate for required height reduction and/or equalization. B, Completing the leaflet reconstruction using running polypropylene suture. C, Completed repair following running annuloplasty. D, Completed repair without residual regurgitation or systolic anterior motion.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The previously described techniques have assumed that the triangular resection performed is symmetric, and that there is an equal tissue volume and height remaining on either side of the posterior leaflet resection. While this is commonly the case with segmental leaflet prolapse, excess tissue can be asymmetric, or there may be deep clefts between valve segments present. In these cases, a typical triangular resection may not result in an adequate posterior leaflet reconstruction. When faced with cases such as these, the previously described ventricularization technique works well. Different respective degrees of leaflet ventricularization for each side of the resection allows the free edge of the reconstructed leaflet to be equalized when the repair is completed. Alternatively, one side of the asymmetric resection can be focused on a deep cleft between valve segments.9Rimsukcharoenchai C. Pandis D. El-Eshmawi A. Anyanwu A.C. Adams D.H. Complex mitral valve regurgitation: surgical evaluation, approach and repair techniques.J Vis Surg. 2021; 7: 15Crossref Google Scholar The cleft serves as one of the lateral resection margins, with the remainder of the resection involving the diseased leaflet segment. The leaflet reconstruction takes place in a standard manner with polypropylene suture, unifying the unresected tissue on the cleft side with the resected edge of the diseased leaflet side. A recently described technique can achieve a similar outcome to the ventricularization previously described. The "butterfly technique" serves as a bridge between the triangular resection and the more extensive quadrangular resection with sliding plasty.17Asai T. The butterfly technique.Ann Cardiothorac Surg. 2015; 4: 370-375PubMed Google Scholar When faced with excessive leaflet height, an initial triangular resection is planned at a predefined height depending on whether P2 or P1/3 are involved. Additional smaller horizontal triangular resections are planned from the apex of the initial triangular resection, extending to the annular level. After completion of these resections, the leaflet margins are rotated toward the annulus, secured, and the leaflet reconstruction completed using polypropylene suture. We do not currently employ this technique, instead favoring leaflet ventricularization, adjunctive neochordae, or the more extensive quadrangular resection with sliding plasty. However, it is an elegant option to decrease posterior leaflet height, has sound physiologic reasoning, and demonstrates encouraging early results.18Asai T. Kinoshita T. Suzuki T. Shiraishi S. Koike M. Early and follow-up results of butterfly resection of prolapsed posterior leaflet in 76 consecutive patients.J Thorac Cardiovasc Surg. 2015; 149: 1296-1300Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar Once the valve repair has been completed, the valve undergoes conventional saline and ink testing to assess the repair adequacy prior to closing the cardiac chamber(s) and weaning from cardiopulmonary bypass. Following a triangular resection, the surgeon is looking for a competent valve with an adequately posterior coaptation point. If coaptation is not adequately posterior, then SAM may be observed once weaned from cardiopulmonary bypass. Although there are accepted algorithms for medically managing SAM, tailoring the operative strategy to predict and avoid SAM is preferable.5Varghese R. Itagaki S. Anyanwu A.C. Trigo P. Fischer G. Adams D.H. Predicting systolic anterior motion after mitral valve reconstruction: using intraoperative transoesophageal echocardiography to identify those at greatest risk.Eur J Cardiothorac Surg. 2014; 45: 132-137Crossref PubMed Scopus (70) Google Scholar,19Varghese R. Anyanwu A.C. Itagaki S. Milla F. Castillo J. Adams D.H. Management of systolic anterior motion after mitral valve repair: an algorithm.J Thorac Cardiovasc Surg. 2012; 143: S2-S7Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar Performing a leaflet ventricularization to decrease posterior leaflet height in those with an increased anticipated risk of SAM should be employed during a triangular resection. If despite the surgeon's best effort, coaptation is excessively anterior (≥50% of the valve orifice), the posterior leaflet is excessively tall (≥15 mm), or if SAM is unexpectedly encountered after weaning from cardiopulmonary bypass, decreasing the relative leaflet height with the addition of neochordae is preferable to revising the entire repair. When leaflet degeneration is more extensive, adjacent segments may show signs of early degeneration, and the usual indentations between valve segments may develop into deeper clefts, occasionally extending to the annular level. These can lead to significant residual MR following repair with a triangular resection, as the reconstruction following triangular resection can pull apart these clefts. These can be easily managed by primarily closing the offending cleft using polypropylene suture. Alternatively, the resection margin can be fashioned to include the cleft as described previously. Mitral valve repair is the gold standard for degenerative mitral valve disease, with excellent survival and durability expecte.1David T.E. David C.M. Tsang W. Lafreniere-Roula M. Manlhiot C. Long-term results of mitral valve repair for regurgitation due to leaflet prolapse.J Am Coll Cardiol. 2019; 74: 1044-1053Crossref PubMed Scopus (54) Google Scholar,4Braunberger E. Deloche A. Berrebi A. Abdallah F. Celestin J.A. Meimoun P. et al.Very long-term results (more than 20 years) of valve repair with Carpentier's techniques in nonrheumatic mitral valve insufficiency.Circulation. 2001; 104: I8-I11Crossref PubMed Google Scholar,20David T.E. Durability of mitral valve repair for mitral regurgitation due to degenerative mitral valve disease.Ann Cardiothorac Surg. 2015; 4: 417-421PubMed Google Scholar,21Mohty D. Orszulak T.A. Schaff H.V. Avierinos J.F. Tajik J.A. Enriquez-Sarano M. Very long-term survival and durability of mitral valve repair for mitral valve prolapse.Circulation. 2001; 104: 1-7Crossref PubMed Scopus (381) Google Scholar For simple segmental posterior leaflet prolapse, triangular resection has been similarly shown to be a safe and effective technique with excellent long-term results.22George K.M. Mihaljevic T. Marc Gillinov A. Triangular resection for posterior mitral prolapse: rationale for a simpler repair.J Heart Valve Dis. 2009; 18: 119-121PubMed Google Scholar,23Sakamoto Y. Hashimoto K. Okuyama H. Ishii S. Kawada N. Inoue T. et al.Mitral valve reconstruction: long-term results of triangular resection for degenerative prolapse.Gen Thorac Cardiovasc Surg. 2008; PubMed Scopus Google Scholar a triangular resection, from mitral valve reintervention at 10 to 20 should be to and it may over the more extensive quadrangular resection when T.E. David C.M. Tsang W. Lafreniere-Roula M. Manlhiot C. Long-term results of mitral valve repair for regurgitation due to leaflet prolapse.J Am Coll Cardiol. 2019; 74: 1044-1053Crossref PubMed Scopus (54) Google Scholar,23Sakamoto Y. Hashimoto K. Okuyama H. Ishii S. Kawada N. Inoue T. et al.Mitral valve reconstruction: long-term results of triangular resection for degenerative prolapse.Gen Thorac Cardiovasc Surg. 2008; PubMed Scopus Google Y. Hashimoto K. Okuyama H. Ishii S. M. Inoue T. et assessment of mitral valve reconstruction with resection of the triangular and quadrangular Thorac Surg. 2005; Full Text Full Text PDF PubMed Scopus Google Scholar the techniques, one can be to achieve excellent operative and postoperative This has the effect of into improved long-term for our mitral valve is a for is a to and and and has right to from reported of The and to of and to or for may have a of The and of this have of Download with Video resection with reconstruction using interrupted sutures. 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