Feasibility and Intermediate Term Outcome of Repair of Prolapsing Anterior Mitral Leaflets With Artificial Chordal Replacement in 152 Patients

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1 Feasibility and Intermediate Term Outcome of of Prolapsing Anterior Mitral Leaflets With Artificial Chordal Replacement in 152 Patients Gerald M. Lawrie, MD, Elizabeth A. Earle, JD, and Nan R. Earle, MS The Methodist DeBakey Heart Center, Houston, Texas CARDIOVASCULAR Background. Mitral valve repair of the anterior leaflet has been more difficult than at other sites. Methods. Between February 1983 and June 2004, 607 mitral valve repairs were performed on one service. Of these, 410 patients had leaflet repair procedures: 152 were anterior leaflet repairs; isolated in 94, and combined with posterior repair in 58 patients. The results in these patients were compared with the results of posterior leaflet repair in 258 patients. All patients received flexible ring annuloplasty. Results. Age and sex of the anterior leaflet and posterior leaflet patients were similar: mean age , years; males, 50.6%, p not significant (NS). Preoperative ejection fraction was for anterior repairs %; posterior repair, %, p NS. Coronary artery bypass was more frequently performed with anterior leaflet repair in 18 patients (19.1%) versus 45 (6.6%) for posterior leaflet repair (p NS). The median number of chordae was similar in the anterior leaflet and posterior leaflet patients 4 (2 8), 4 (2 6), p NS. Perioperative mortality was similar: anterior leaflet patients, 3.3% (2/94); posterior leaflet patients, 1.1% (2/258), p NS. Hospital stay was for anterior leaflet patients and posterior leaflet patients: vs , p NS. Kaplan-Meier estimates of freedom from reoperation at 3 years were: for anterior leaflet patients, 91.9%: for posterior leaflet patients, 90.7%, p No structural polytetrafluoroethylene (PTFE) chordal failures were observed. Late echocardiographic data were obtained in 136 patients on 222 occasions at a mean of years. Severe mitral regurgitation was present in 10 patients (7.3%). Conclusions. of the anterior leaflet is facilitated by the use of PTFE replacement. Anterior leaflet repair can be performed reproducibly with the same results as posterior leaflet repair. (Ann Thorac Surg 2006;81:849 56) 2006 by The Society of Thoracic Surgeons of prolapse of the anterior mitral leaflet, especially when extensive, has been considered more difficult than repair of the posterior mitral leaflet [1 8]. Previously described techniques of anterior leaflet repair such as chordal transposition have indeed been more complex than those for posterior leaflet repair [4 7]. In recent years there has been improved understanding of the pathology of prolapsing leaflets and chordae, and mitral valve pathophysiology [9 11]. Myxomatous mitral valve prolapse is now seen to be primarily due to disease of the marginal chordae tendinae. These developments, and the introduction of polytetrafluoroethylene (PTFE) suture material for chordal replacement, have led to marked simplification of mitral valve reparative techniques. The same techniques of artificial chordal replacement have been applied with equal success to anterior and posterior leaflets [12 18]. The aim of this study was to document the outcome of anterior leaflet and bileaflet repair using these techniques and to compare the results to those of posterior leaflet repair. Accepted for publication Aug 29, Presented at the Forty-first Annual Meeting of The Society of Thoracic Surgeons, Tampa, FL, Jan 24 26, Address correspondence to Dr Lawrie, 6560 Fannin, #1842, Houston, TX 77030; gmlawrie@att.net. Material and Methods Between January 1983 and June 2004, 607 patients underwent mitral valve repair on one surgical service. Of these patients, 410 had procedures involving repair of prolapsing or flail leaflets. There were 152 anterior leaflet repairs which were isolated in 94 and combined with posterior repair in 58 patients. The results of surgery in these patients were compared with the results of posterior leaflet repair in 258 patients. The preoperative clinical characteristics of these patients are summarized in Table 1. Data are provided for patients who underwent anterior leaflet repair, combined anterior and posterior leaflet repair, and posterior leaflet repair alone. The preoperative mitral valve pathological findings are summarized in Table 2. Follow-up was prospective by regular letter mailings and telephone contact and information from treating physicians. Statistical Analysis The data were recorded on custom forms and entered into a custom database. The database and its supporting programs were written in ANSI Standard MUMPS (now called M). The current version is DTM v 6.4 (InterSystems Corporation, Cambridge, MA). The data and programs reside on a Pentium III Personal Computer running 2006 by The Society of Thoracic Surgeons /06/$32.00 Published by Elsevier Inc doi: /j.athoracsur

2 CARDIOVASCULAR 850 LAWRIE ET AL Ann Thorac Surg REPAIR OF PROLAPSING ANTERIOR MITRAL LEAFLETS 2006;81: Table 1. Comparison of Preoperative Characteristics of the Three Groups of Patients in the Study Variable Anterior Leaflet Bileaflet Posterior Leaflet p Value Age (years) Sex (male) 43 (45.7%) 36 (62.1%) 151 (58.5%) NYHA-III-IV 52 (67.5%) 36 (69.2%) 124 (59.3%) Prior MI 20 (23.5%) 8 (15.4%) 24 (9.6%) Prior CAB 6 (7.5%) 2 (3.8%) 7 (3.2%) LVEF Severe MR 57 (60.6%) 42 (72.4%) 201 (77.9%) Atrial fibrillation 35 (37.6%) 15 (26.3%) 88 (34.6%) CAB coronary artery bypass; LVEF left ventricular ejection fraction; MI myocardial infarction; MR mitral regurgitation; NYHA New York Heart Association. Windows 98, 2 nd editions, v a (Microsoft Corp, Redmond, WA). Data analysis was carried out in three different statistical packages: BMDP Statistical Software (BMDP Dynamic, release 7.0, SPSS, Inc, Chicago, IL); S-Plus v 6.0 (Insightful Corporation, Seattle, WA); and a custom MUMPS package validated against BMDP. A MUMPS routine was written to transfer the variables of interest into an ASCII space-delimited file which was then imported into BMDP and S-Plus. The MUMPS routines were used primarily for data record selection to find all patients who had primary mitral valve repair and to perform preliminary analyses. Formal statistical analyses were carried out in BMDP: 2 analyses for categorical data, analysis of variance for continuous variables, and Cox proportional hazard analysis for predictors of survival and freedom from reoperation. Both forward and backward stepping models were used. The S-Plus was used for Kaplan-Meier survival analyses and to plot the resulting graphs. Significant statistical differences were considered to exist if p was less than There was no adjustment for multiple tests. Surgical Techniques Preoperative and intraoperative transesophageal echocardiographic images are reviewed. A standardized technique has been developed which is used for all prolapsing valve disease. The chest is entered either through a full median sternotomy or a limited lower sternal incision. The superior and inferior vena cavae are extensively Table 2. Pathology of the Mitral Valves According to the Leaflets ed Anterior Leaflet Leaflet Pathology Bileaflet Posterior Leaflet Degeneration 13 (15.7%) 4 (7.7%) 10 (4.3%) Myxomatous 26 (31.3%) 23 (44.2%) 115 (49.8%) Both 18 (21.7%) 15 (28.8%) 67 (29.0%) Ischemic 10 (12.0%) 4 (7.7%) 9 (3.9%) p mobilized. Cardiopulmonary bypass is established with bicaval 24-French cannulas, vena caval tapes, and dynamic venous drainage. The heart is arrested with retrograde cardioplegia. The left atrium is entered through an interatrial incision and the mitral valve is exposed. Stay stitches of 2-0 polypropylene are placed at the following: two at the commissures into the right and left fibrous trigones, and two or three in the posterior annulus. The annulus, valve leaflets, chordae, and papillary muscles are examined. The left ventricle is inflated with 75 to 100 ml of saline. The abnormal structures are identified. Leaflet prolapse is corrected by insertion of No. 5 PTFE sutures. The sutures are first placed into the bases of the posteromedial and/or anterolateral papillary muscles in a figure of eight fashion (Fig 1A). The PTFE chordae are brought through the free edge of the prolapsing segment as a rolling suture (Fig 1B). This provides sufficient friction to hold the length of the chordae constant during adjustment of the realignment of abnormal leaflet segment with the adjacent and opposite leaflet edges. Dots are placed 5 10 mm from the free edges of the leaflets with a marker pen to mark the desired line of apposition (Fig 1C). The ventricle is again inflated with saline. The chordal length is adjusted to align the edges of the leaflets (Fig 1D). The two stay stitches in the posterior annulus are brought forward to simulate the effects of the annuloplasty ring on the posterior annulus so as to bring the lines of dots on both leaflets into apposition. Leaflet alignment is checked and the PTFE chordae are further adjusted as needed (Fig 1E). At this point the mitral orifice is sized according to its circumference and the appropriate flexible ring chosen. The PTFE is tied down with ten throws and the knot is locked with a 6-0 polypropylene stitch tied over the end of the PTFE knot in order to prevent sliding of the PTFE knots. The annuloplasty ring is secured to the annulus with the previously placed commissural 2-0 sutures in continuous fashion (Fig 1F). The valve is again tested by saline insufflation of the left ventricle. The marking dots and PTFE knots should be buried in the line of apposition. The left atrium is closed. The air is evacuated, warm blood cardioplegia given, and the aorta unclamped. The operation is completed and the repair is checked by

3 Ann Thorac Surg LAWRIE ET AL 2006;81: REPAIR OF PROLAPSING ANTERIOR MITRAL LEAFLETS 851 CARDIOVASCULAR Fig 1. Details of the surgical technique employed. (A) Number 5 PTFE suture is passed through the basal portion of the papillary muscle in figure of 8 fashion. (B) Each needle is passed through the edge of the leaflet twice, in a rolling fashion towards the center of each pair. The needle can be seen completing this for the medial pair of chordae. (C) Dots are placed to mark the desired final line of leaflet apposition using a marker pen (top). Note also the four annular 2-0 polypropylene stay stitches. (D) The left ventricle is inflated with saline and the chordal length is adjusted. (E) The annular stay stitches are used to simulate the correct annular size during further insufflation and chordal adjustment. (F) The chordae are tied down and the flexible annuloplasty ring is attached with a continuous 2-0 polypropylene suture. The dots and polytetrafluoroethylene knots are now buried in the line of leaflet position. transesophageal echocardiography. Further technical details, including a video of this technique, are available at All patients underwent postoperative transthoracic echocardiography prior to discharge. Late echocardiographic data were obtained in 136 patients on 222 occasions at a means interval of years. There were 34 anterior leaflet patients, 28 bileaflet patients, and 74 posterior leaflet patients. The surgical procedures performed on the mitral valves of the 410 study patients are summarized in Table 3. Anterior leaflet repair alone involved PTFE chordal replacement in 91.5% of patients and 88.0% of patients having bileaflet repair. The median number of PTFE chordae used is shown in Table 3. Initially, classical quadrantic resection was used for posterior leaflet repair but has been abandoned completely in favor of PTFE chordal replacement since Partial or complete ring annuloplasty was performed in all patients. Other concomitant procedures were performed in 135 (32.9%) patients and are summarized in Table 4, along with clamp time and cardiopulmonary bypass time. It was notable that coronary bypass was more frequently performed with anterior leaflet repair in 18 patients (19.1%) vs 45 (6.6%) for posterior leaflet repair. However, this difference did not reach statistical significance. Other procedures included tricuspid valve repair and atrial fibrillation ablative procedures. Perioperative data are summarized in Table 5. Overall perioperative mortality (30 days) was 2.9% (12/410) and for isolated mitral valve repair was 1.5% (4/275). For the 73 patients who have mitral repair and coronary artery bypass it was 6.8% (5/73). Factors affecting the risk of need for reoperation from the Cox multivariable forward stepping analysis are shown in Table 6. The time-related Results Table 3. Surgical Techniques Employed According to the Leaflets ed Anterior Leaflet Bileaflet Posterior Leaflet PTFE chordal 80 (85.1%) 27 (46.6%) 160 (62.0%) replacement Leaflet 7 (7.4%) 7 (12.1%) 63 (24.4%) resection/ plication Both 6 (6.4%) 24 (41.4%) 22 (8.5%) No. PTFE 4.0 (2 8) 7.9 (4 16) 4.0 (2 6) chordae (median, range) Flexible ring annuloplasty 94 (100%) 58 (100%) 258 (100%) p for differences between the groups. PTFE polytetrafluoroethylene.

4 CARDIOVASCULAR 852 LAWRIE ET AL Ann Thorac Surg REPAIR OF PROLAPSING ANTERIOR MITRAL LEAFLETS 2006;81: Table 4. Associated Surgical Procedures Performed at the Time of Mitral, According to the Leaflets ed Concomitant CABG Concomitant AVR Other procedures Clamp time, mean (min) Bypass time, mean (min) Anterior Leaflet Bileaflet Posterior Leaflet p Value 18 (19.1%) 10 (17.2%) 45 (6.6%) (6.4%) 2 (3.4%) 12 (4.7%) (24.5%) 10 (17.2%) 40 (15.5%) AVR aortic valve replacement; CABG coronary artery bypass grafting. risk of reoperation was compared among the 410 patients of the three different study groups and the remaining 197 patients who had mitral valve procedures with no leaflet repair. The reoperation rates were not statistically different through 10 years of follow-up (Fig 2). The influence of leaflet pathology on risk of need for reoperation is shown in Figure 3. Factors predictive of patient survival from the Cox multivariable forward stepping analysis are shown in Table 7. The results of the comparison of the timerelated influence on patient survival of the leaflets repaired or no leaflet repair are shown in Figure 4. The influence of coronary disease on survival demonstrated in Table 7 was further analyzed by Kaplan-Meier analysis and the results are shown in Figure 5. The deleterious influence on survival of unbypassed coronary disease was clearly shown. Overall rates of stroke were compared in Figure 6. The rates were similar for all groups. The results of the echocardiographic studies are shown in Tables 8 10 and Figure 7. As shown in Table 8, of136 patients 10 (7.4%) had severe mitral regurgitation at follow-up. There were no significant differences among the three study groups in regard to the severity of mitral regurgitation (p 0.402). The influence of type of leaflet pathology on the echocardiographic result is shown in Table 9. The ischemic group had the fewest patients in the none/mild category but the differences did not reach significance. In Table 10 the results of a comparison of all patients treated with PTFE only were compared with all patients treated with traditional leaflet resection techniques only. The results were almost identical (p 0.884). In Figure 7 a comparison is presented of the severity of mitral regurgitation at the time of hospital discharge and the severity of mitral regurgitation on the latest echocardiogram. The differences did not reach significance (p 0.533). However, in this analysis only 9 patients were discharged with moderate mitral regurgitation and none with severe regurgitation. Comment Unlike the posterior mitral leaflet, the anatomy of the anterior mitral leaflet does not lend itself to repair of prolapsing segments by extensive leaflet resection. It is roughly rhomboidal in shape. Although it is almost equal in surface area to the posterior leaflet it has a base of fixed dimension (the aortic-mitral continuity) which occupies only one third of the annular mitral leaflet attachments. There is little redundancy of its area. It has to swing freely through a wide arc to achieve proper apposition with the U-shaped surface formed around the posterior two thirds of the ostium of the left ventricle by the posterior leaflet. Even triangular resection as described by Carpentier [1 3] is prone to cause loss of mobility of the leaflet due to the drumhead effect across the free edge of the leaflet. After many years of unsuccessful experimentation with other chordal substitutes [19, 20] the decade of the 1980s saw PTFE suture introduced into clinical practice by Reveulta in Spain, Frater in New York, and David in Toronto [12, 13, 21 23]. Chordal replacement with No. 5 PTFE suture has proven to be a simple, versatile, and durable technique in our own experience. It has a number of advantages. Normal chordae and normal leaflet motion are not disturbed as there is no need for native Table 5. Postoperative Outcomes According to Leaflets ed Anterior Leaflet Bileaflet Posterior Leaflet p Value Severity of mitral regurgitation 91 (96.8%) 56 (96.5%) 247 (95.7%) (none/mild) Hospital stay (days) Perioperative mortality 2 (3.3%) 0 2 (1.1%) (isolated repairs) Years follow-up

5 Ann Thorac Surg LAWRIE ET AL 2006;81: REPAIR OF PROLAPSING ANTERIOR MITRAL LEAFLETS Table 6. Results of Cox Multivariable Forward Stepping Analysis for Factors Predictive of Need for Reoperation Significant Variable Relative Risk p Value Table 7. Results of Cox Multivariable Forward Stepping Analysis for Factors Predictive of Patient Survival 853 Significant Variable Relative Risk p Value CARDIOVASCULAR Prior MI Concurrent CABG CABG coronary artery bypass grafting; MI myocardial infarction. Age 1.03/yr Prior CABG CAD but no concurrent CABG CABG coronary artery bypass grafting; disease. CAD coronary artery chordal transposition. The number of abnormal chordae which can be replaced is unlimited. This is particularly advantageous when both the anterior and posterior leaflets have severe prolapse. Indeed, the presence of severe bileaflet disease poses no difficulty. On the other hand, with older techniques severe bileaflet disease may be more difficult to repair and may be associated with mitral valve replacement in as many as 20% of patients when conventional chordal transposition procedures are attempted. After our initial experience in a few cases with resectional techniques, all prolapsing anterior leaflets subsequently have been repaired with PTFE chordal replacement as the primary technique for more than 20 years. Perhaps the single greatest advantage of PTFE repair is the simplicity with which complete replacement of all chordae, if necessary, can be achieved. Indeed, the data in Table 3 clearly demonstrated that some anterior leaflets required such extensive chordal replacement that chordal transposition techniques would have been very difficult to apply. Fig 2. Results of Kaplan-Meier analysis of the influence of the leaflet repaired or nonleaflet repair on the need for reoperation after mitral valve repair. ( anterior; both; posterior; neither.) Fig 4. Results of Kaplan-Meier analysis of the influence of the leaflet repaired or nonleaflet repair on patient survival. ( anterior; both; posterior; neither.) Fig. 3. Results of Kaplan-Meier analysis of the influence of leaflet pathology on need for reoperation after mitral valve repair. Fig 5. Results of Kaplan-Meier analysis of the influence on patient survival of coronary artery disease (CAD) and whether or not concomitant coronary bypass (CAB) was performed. ( no CAD; CAD plus CAB; CAD no CAB.)

6 CARDIOVASCULAR 854 LAWRIE ET AL Ann Thorac Surg REPAIR OF PROLAPSING ANTERIOR MITRAL LEAFLETS 2006;81: Table 10. Results of Late Echocardiograms in 136 Patients According to Whether Leaflet Resection or PTFE Chordae Were Used Severity of Late Mitral Regurgitation None/mild Moderate Severe Leaflet resection 24 (72.7%) 6 (18.2%) 3 (9.1%) PTFE chordae 78 (76.5%) 17 (16.7%) 7 (6.9%) p for differences between resection and polytetrafluoroethylene, (PTFE) groups. Fig 6. Results of Kaplan Meier analysis of the influence the leaflet repair or no leaflet repair on overall rates of stroke. ( anterior; both; - - posterior; neither.) The surgical technique described here is the systematic approach we use for every case of mitral valve leaflet prolapse regardless of site. The most important difference in the technique described compared with previous reports is that we have developed a method for realigning the edges of prolapsing segments with the PTFE chordae, which restores the original area of apposition of the leaflets. This method duplicates the end-diastolic state of the size of the chordae and the papillary annular distances. It allows the annular and chordal dimension to be adjusted together. This involves marking the line of apposition on the leaflets and then displacing the posterior annulus forward during inflation of the ventricle with saline in order to determine the size of permanent ring annuloplasty necessary to achieve physiological leaflet apposition and the final length of the PTFE chordae. This inflation simulates the end-diastolic elongation of the long axis of the left ventricle. This result is important not only to obtain resolution of the mitral regurgitation but also is critically important in reducing the stress on the new PTFE marginal chordae through the keystone effect [10, 11]. Stroke was uncommon after valve repair and the rates were similar for all the groups studied. We have not employed anticoagulation at any stage after surgery in patients with sinus rhythm and have had a very low incidence of thromboembolism. Sodium warfarin is prescribed only when chronic atrial fibrillation was present, left atrial thrombus was encountered, or preoperative thromboembolism had occurred. We studied the use of coumadin after mitral valve repair in a series of 561 isolated mitral valve repairs. We documented that, of 351 patients discharged in sinus rhythm on no coumadin, there were no strokes in the first six months after surgery [23]. The patients in this study with anterior leaflet prolapse had a higher incidence of previous myocardial infarction and more depression of left ventricular ejection fraction (Table 1). Despite this, their clinical outcome after PTFE repair was similar to the patients with only posterior lesions in regard to reoperation, echocardiographic results, and survival. A notable finding in this study was the deleterious impact of unbypassed coronary artery disease on overall survival and the beneficial effect of CAB on avoidance of reoperation. Table 8. Results of Late Echocardiograms in 136 Patients According to the Severity of the Mitral Regurgitation on Their Latest Study Anterior Leaflet Both Leaflets Posterior Leaflets Total None/mild 25 (73.5%) 23 (85.2%) 54 (73.0%) 100 (75.6%) Moderate 7 (20.6%) 4 (14.8%) 12 (16.2%) 23 (17.0%) Severe 2 (5.9%) 0 8 (10.8%) 10 (7.4%) p for differences among the three repair groups. Table 9. Results of Late Echocardiograms in 136 Patients According to the Preoperative Leaflet Pathology Severity of Mitral Regurgitation Leaflet Pathology None/Mild Moderate Severe Total Rheumatic 8 (72.7%) 3 (27.3%) 0 Ischemic 5 (62.5%) 3 (37.5%) 0 Myxomatous/degenerative 89 (76.1%) 19 (16.2%) 10 (8.5%) 117 Other

7 Ann Thorac Surg LAWRIE ET AL 2006;81: REPAIR OF PROLAPSING ANTERIOR MITRAL LEAFLETS Fig 7. Comparison of the status of the patients at most recent echocardiographic study according to their echocardiographic status at the time of hospital discharge. (Black bar none/mild, 102; grey bar moderate, 23; white bar severe, 10; p ) The results of the analyses in this study comparing the results of PTFE chordal replacement with traditional resectional techniques demonstrated no differences in outcome despite the application of PTFE chordal repair to patients usually considered to be unrepairable by other techniques. Long-term echocardiographic follow-up for the Carpentier techniques is limited. The largest study is that of Flameng and colleagues (8) who studied 242 patients who had serial echocardiograms every 6 months. At 8 years after repair they documented % patient survival and freedom from reoperation of %. Freedom from grade 3/4 or 4/4 mitral regurgitation on echocardiography was % at 7 years. The clinical and echocardiographic results described here are similar to those documented in earlier reports of PTFE usage [15, 17, 24]. David and colleagues [15] documented no adverse impact of PTFE chordal reconstruction on any endpoint. The results of anterior leaflet repair in our experience were markedly better than that reported by Molitz and colleagues [25]. They experienced an 11% reoperation rate at 5 years and an 18% reoperation rate at 10 years. In the Cleveland Clinic experience [4, 5] in which the traditional Carpentier techniques were used, anterior leaflet repair was associated with a significantly higher risk of need for reoperation. Freedom from reoperation was 74% at 5 years for chordal shortening and 96% after chordal transfer. We feel that our experience confirms the experience of others (6, 12 18), that PTFE chordal replacement is a simple, expeditious, and durable technique for repair of mitral insufficiency arising from anterior leaflet prolapse. Given the fact that anterior leaflet repair has been widely reported to be a predictor of increased risk of need for reoperation, we find the fact that the anterior leaflet outcomes were similar to the posterior leaflet outcomes to be an encouraging finding of the study. The authors are indebted to Dr Michael E. DeBakey for his support and encouragement during the early phases of this work. References Carpentier A, Chauvaud S, Fabiani J, et al. Reconstructive surgery of mitral valve incompetence. J Thorac Cardiovasc Surg 1980;79: Carpentier A. Cardiac valve surgery the French correction. J Thorac Cardiovasc Surg 1983;86: Deloche A, Jebara VA, Relland JY, et al. Valve repair with Carpentier techniques. J Thorac Cardiovasc Surgery 1990;99: Smedira NG, Selman R, Cosgrove DM, et al. of anterior leaflet prolapse: chordal transfer is superior to chordal shortening. J Thorac Cardiovasc Surg 1996;112: Gillinov AM, Cosgrove DM, Blackstone EH, et al. Durability of mitral valve repair for degenerative disease. J Thorac Cardiovasc Surg 1998;116: Phillips MR, Daly RC, Schaff HV, Dearani JA, Mullany CJ, Orszulak TA. of anterior leaflet mitral valve prolapse: chordal replacement versus chordal shortening. Ann Thorac Surg 2000;69: Salati M, Scrofani R, Fundaro P, Cialfi A, Santoli C. Correction of anterior mitral prolapse. J Thorac Cardiovasc Surg 1992;104: Flameng W, Herijgers P, Bogaerts K. Recurrence of mitral valve regurgitation after mitral valve repair in degenerative valve disease. Circulation 2003;107: Barber JE, Kasper FK, Ratliff NB, Cosgrove DM, Griffin BP, Vesely I. Mechanical properties of myxomatous mitral valves. J Thorac Cardiovasc Surg 2001;122: Nielsen SL, Nygaard H, Fontaine AA, et al. Chordal force distribution determines systolic mitral leaflet configuration and severity of functional mitral regurgitation. J Am Coll Cardiol 1999;33: Nazari S, Carli F, Salvi S, et al. Patterns of systolic stress distribution on mitral valve anterior leaflet chordal apparatus. A structural mechanical theoretical analysis. J Cardiovasc Surg(Torino) 2000;41: David T. Replacement of chordae tendineae with expanded polytetrafluoroethylene sutures. J Card Surg 1989; 4: David TE, Bos J, Rakowski H. Mitral valve repair by replacement of chordae tendineae with polytetrafluoroethylene sutures. J Thorac Cardiovasc Surg 1991;101: Zussa C, Polesel E, DaCol U, Galloni M, Valfre C, Frater RW. Seven-year experience with chordal replacement with expanded polytetrafluoroethylene in floppy mitral valve. J Thorac Cardiovasc Surg 1994;108: David TE, Omran A, Armstrong S, Sun Z, Ivanov J. Longterm results of mitral valve repair for myxomatous disease with and without chordal replacement with expanded polytetrafluoroethylene sutures. J Thorac Cardiovasc Surg 1998; 115: Tomita Y, Yasui H, Tominaga R, et al. Extensive use of polytetrafluoroethylene artificial grafts for prolapse of bilateral mitral leaflets. Eur J Cardiothorac Surg 2002;21: Kobayashi J, Sasako Y, Bando K, Minatoya K, Niwaya K, Kitamura S. Ten-year experience of chordal replacement with expanded polytetrafluoroethylene in mitral valve repair. Circulation 2000;102(suppl 3):III-30-4). 18. Marchand P, Barlow JB, DuPlessis LA, Webster I. Mitral regurgitation with rupture of normal chordae tendineae. Br Heart J 1966;28: Rittenhouse EA, Davis CC, Wood SJ, Sauvage LR. Replacement of ruptured chordae tendineae of the mitral valve with autologous pericardial chordae. J Thorac Cardiovasc Surg 1978; Revuelta JM, Garcia-Rinaldi R, Gaite L, Val F, Garijo F. Generation of chordae tendineae with polytetrafluoroethylene stents. J Thorac Cardiovasc Surg 1989,97: CARDIOVASCULAR

8 CARDIOVASCULAR 856 LAWRIE ET AL Ann Thorac Surg REPAIR OF PROLAPSING ANTERIOR MITRAL LEAFLETS 2006;81: Frater RW, Vetter HO, Zussa C, Dahm M. Chordal replacement in mitral valve repair. Circulation 1990;82(suppl 4):IV Zussa C, Polesel E, Rocco F, Galloni M, Frater RW, Valfre C. Surgical technique for artificial mitral chordae implantation. J Card Surg 1991;6: Lawrie GM, Earle E, Earle N. Is coumadin necessary after mitral valve repair? Chest 2004;126:734S. 24. David TE, Ivanov J, Armstrong S, Rakowski H. Late outcomes of mitral valve repair for floppy valves: implications for asymptomatic patients. J Thorac Cardiovasc Surg 2003; 152: Molitz D, Orszulak TA, Schaff HV, Avierinos JF, Tajik JA, Enriquez-Sarano M. Very long-term survival and durability of mitral valve repair for mitral valve prolapse. Circulation 2001;104(suppl 1):I-1 7. DISCUSSION DR VINAY BADHWAR (St. Petersburg, FL): Congratulations on a nice presentation. Prior to advocating widespread use of neochordal replacement therapy, clearly there are different ways of repairing the mitral valve. I have two fundamental questions. In the anterior leaflet repair group, did you account for posterior leaflet height as this often affects the zone of coaptation length, and if so, how many of those patients had a sliding annuloplasty to augment the zone of coaptation? Furthermore, in your chordal replacement groups without a posterior slide, how many had systolic anterior motion of the mitral leaflet? The second question relates to your illustration of a mixed bag of mitral regurgitation etiologies in your series. Some of these are ischemic. Of the 10% three-year failure rate in the posterior repair only, how many of those were true ischemic etiology as opposed to myxomatous or degenerative, and have you since altered your technique and approach by using a remodeling annuloplasty? Thank you. DR LAWRIE: Well, as you saw, the ischemic group was in the minority. These were people who actually had ischemic damage that resulted in abnormal leaflet motion of the anterior leaflet, and so these people were treated with annuloplasty and reconstruction of the relevant area needed to stabilize the anterior leaflet. You will see occasional patients with anterior leaflet abnormalities from ischemia. This technique is a nonresectional technique. I invite you to join our new society, PETL, People for the Ethical Treatment of Leaflets. We have completely given up, abandoned, never do resection of the anterior or posterior leaflet. I would humbly submit to you, and I know this is going to provoke perhaps more discussion, that there is no such thing as leaflet height and that there is no such thing as excessively large leaflets. Myxomatous degeneration is characterized by annuli that are double normal size, by leaflets that are double normal size, and by chordae that are double normal length. The mitral regurgitation occurs because of the diseased chordae. The logical rational way to get the prolapsing leaflets replaced where they belong in my opinion is what I have shown you in this video. It is a marked overlap. We calculate the overlap, we mark it on the leaflet, and then we adjust the anatomy to do it. When you do this, you do not get systolic anterior motion. The average ring size in this group of patients is 31 to 33 mm. It is extremely rare at the end of the annuloplasty simulation maneuver to need more than a 31 mm annuloplasty. Chordal replacement is not associated with SAM (systolic anterior motion), except perhaps in rare cases we have seen some chordal SAM, because we are using large annuloplasty rings, and the reason we are able to use large annuloplasty rings is we have not resected any of our leaflet area. DR DANIEL H. DRAKE (Traverse City, MI): I also congratulate you on your presentation. It was excellent. Papillary muscle shortening as originally described by Professor Alain Carpentier is the technique that I prefer to use for the repair of anterior leaflet prolapse. Please explain your preference for artificial chords. DR LAWRIE: We try to keep things as simple as possible, and artificial chordal replacement is an incredibly simple way of solving the problem. The pathology of myxomatous degeneration is that the chordae themselves have mechanical disability. This is what we saw from the data from the Cleveland Clinic studies that were published in the Journal of Thoracic and Cardiovascular Surgery. The mitral insufficiency of myxomatous disease is primarily a disease of the chordae, and we suggest that the rational treatment for that is chordal replacement, placing the chordae as I have shown and using the maneuvers I have shown that make it very easy to get the length correct. DR KEVIN D. ACCOLA (Orlando, FL): Dr Lawrie, that s a very innovative thought process in regards to dealing with elongated chordae. From a technical perspective I would like to ask your sizing technique for the annulus. As you know, all these patients typically have annular dilatation with an increased anteriorposterior dimension. How do you account for this when you size the annulus since you are not using the typical annular sizing techniques we have all become accustomed to; that is, sizing the anterior leaflet or the intertrigonal space? DR LAWRIE: That is a very good question, Kevin. The average annular size preop is in the 48 to 50 mm range. The fact of the matter is if you put a flexible ring annuloplasty on it, a symmetrically reducing annuloplasty around the posterior two-thirds of the annulus, you will reduce the size to 33 mm if you put a 33 mm ring. Now, as far as the shape of the annulus is concerned, since we have been doing a lot of 3D echo in your unit, the fact is that the shape of the heart without any disciplinary measures is a D-shaped annulus. So we see something that is exactly what you are used to seeing except that is the natural shape of that annulus after it has been reduced and the leaflets are back in position.