Mitral valve repair for anterior leaflet prolapse: surgical techniques review and 16-year follow-up results

Abstract   Objective: Mitral valve repair is now the surgical treatment of choice for mitral regurgitation. However, the repair of anterior leaflet prolapse due to chordal rupture or elongation remains a technically challenging procedure. Here, we review our experience and present the long-term results of mitral valve repair for mitral regurgitation due to anterior leaflet prolapse. Methods: Between January 1988 and August 2006, 210 patients with mitral regurgitation underwent mitral valve reconstruction. We performed mitral valve repair in 49 patients with mitral regurgitation due to anterior leaflet prolapse. The preoperative degree of mitral regurgitation was moderate to severe in all patients. There were 36 patients (73.5%) with degenerative, eight (16.3%) with infective endocarditis, and five (10.2%) with rheumatic. Reconstructive techniques included chordal replacement in 13 patients, chordal shortening in 14, chordal transposition in five, chordal shortening and reinforcement with artificial chordae in four, leaflet folding plasty in six, and resection-suture in four. Results: Follow-up was complete with an average of 89 ± 59 months (range 1–201 months). In the early postoperative period, transthoracic echocardiography was performed in all patients. The grade of regurgitation was trivial (Grade I) in 17 patients (34.7%) and mild (Grade II) in seven patients (14.3%). Survival rate at 10 and 15 years was 95.2% and 88.9%, respectively. Freedom from reoperation at 10 and 15 years was 95.8% and 89.0%, respectively. Conclusions: The long-term results of mitral valve repair for anterior leaflet prolapse are satisfactory, with low mortality and morbidity. In particular, chordal replacement using temporary Alfieri stitch is a simple and effective procedure.     

Chordal transfer for repair of anterior leaflet prolapse

A variety of techniques have been developed for repair of prolapse of the anterior leaflet of the mitral valve. At The Cleveland Clinic Foundation, we favor chordal transfer for this entity. In most instances, normal chordae with a strip of leaflet tissue are transferred from the posterior leaflet to the free edge of the unsupported anterior leaflet; the posterior leaflet is repaired in standard fashion employed for quadrangular resection. In selected cases, chordal transfer is accomplished by transfer of secondary anterior leaflet chordae to the unsupported free edge. Because normal chordae are used in both instances, there is no need for measurement of chordae or judgment of their length. With this technique for correction of anterior leaflet prolapse, 5-year freedom from reoperation after mitral valve repair is 96%.     

The rheumatic mitral valve and repair techniques in children

The mitral valve is the most commonly affected valve in acute and chronic rheumatic heart disease in the first and second decades of life. Pure or predominant mitral regurgitation with non-significant stenosis (mitral valve area > 1.5 cm(2) on echocardiography) is the most frequently encountered valvular dysfunction in children. In our experience, based on 428 children operated between 1993 and 2011 at our institution, functional classification based on leaflet motion assessed by echocardiography and reconfirmed peroperatively revealed pure annulus dilatation (type I) in 7% of patients, anterior leaflet prolapse (type IIa) in 33%, combination of anterior leaflet pseudoprolapse with restricted motion of the posterior leaflet (type pseudoIIa/IIIp) in 34%, and restricted anterior and posterior leaflet motion (type IIIa/p) in 26%. Patients with type III were older than those with type IIa and type pseudoIIa/IIIp. Different techniques can be used to repair rheumatic mitral valve lesions: prolapse of the anterior leaflet caused by chordal elongation or rupture can be treated by chordal shortening, chordal transfer, or artificial chordal replacement; restricted motion of the anterior and/or posterior leaflet can be treated by commissurotomy, splitting of the papillary muscles, resection of the secondary, or sometimes primary posterior chordae, posterior leaflet free edge suspension, leaflet thinning, and leaflet enlargement using autologous pericardium. Because mitral annulus dilatation is present in almost all patients with mitral regurgitation, concomitant ring annuloplasty offers more stability in valve repair, improving long-term outcome. The major causes for failure of rheumatic mitral valve repair are the presence of ongoing rheumatic inflammation at the time of surgery, use of inappropriate techniques, technical failures requiring early reoperation, lack of concomitant ring annuloplasty, and progression of leaflet and chordal disease further resulting in more leaflet retraction, thickening, and deformity. Freedom from reoperation depends on mitral regurgitation functional type, the type IIa and type pseudoIIa/IIIp having a better long-term outcome than type I and type III, in our series. In conclusion, mitral valve repair should be a preferred strategy in children with rheumatic heart disease whenever feasible, providing stable actuarial survival with fewer thromboembolic complications in a pediatric population noncompliant to anticoagulation.     

Anterior mitral leaflet prolapse as a primary cause of pure rheumatic mitral insufficiency

BACKGROUND: This study was designed to revise the mechanisms and repair techniques of anterior mitral leaflet prolapse observed during the correction of pure rheumatic mitral regurgitation in children. METHODS: From March 1993 to May 1998, 36 children suffering from pure rheumatic mitral regurgitation due to anterior leaflet prolapse underwent mitral valve repair. The mean age was 12.5 years (range, 6 to 16 years). Anterior leaflet prolapse was due to chordal elongation in 25 patients (group A), chordal rupture in 6 patients (group B), and retraction of anterior secondary chordae tendineae, creating a V-shaped deformity in the middle of the anterior leaflet, thus moving the free edge of the anterior leaflet away from the coaptation plane, in 5 patients (group C). Chordal shortening, transposition, and resection of anterior secondary chordae tendineae were used to correct anterior leaflet prolapse according to the predominantly responsible mechanism. RESULTS: All patients were available for clinical follow-up, which ranged from 6 months to 5 years (mean follow-up, 3 years). Echocardiographic studies were obtained until the 3rd postoperative month, and all patients showed significant improvement in their left ventricular and atrial dimensions. There was one late death related to endocarditis. Two patients in group C who had mitral valve repair underwent mitral valve replacement on the 19th and 24th postoperative months, respectively, because of failure of mitral valve repair. CONCLUSIONS: Mitral valve repair for pure mitral regurgitation due to rheumatic anterior leaflet prolapse can be performed safely for all types of mechanisms. Although the techniques we used provide stable short-term results in each of these groups, midterm results are better in groups A and B, where tissue thickening is less important, recurrences of rheumatic carditis are lower, and the interval between the first rheumatic attack and the surgical procedure is shorter than in group C.     

改良腱索转移法治疗二尖瓣前叶脱垂(附16例临床分析)

目的 介绍一种操作简单、效果可靠的矫治二尖瓣前叶脱垂的手术方法.方法 2002年1月至2008年5月,应用"缘对缘"技术基础上的腱索转移法治疗二尖瓣前叶脱垂共16例,其中腱索断裂12例,腱索延长4例.超声心动图均显示二尖瓣前叶脱垂致重度关闭不全,平均反流面积(14.76±3.28)cm2,左心室射血分数33%～69%.按照NYNA分级,术前心功能Ⅲ级5例,Ⅳ级11例.手术首先行脱垂部位前瓣与相应部位后瓣的"缘对缘"缝合,矩形切下缝合处的后瓣,连同相应的腱索、乳头肌,转移至前瓣.再行后瓣成形,完成瓣膜成形手术.所有病人出院前和随访时再次行超声心动图检查.结果 手术无死亡,除1例因为术后第3天出现二尖瓣前叶穿孔再次行二尖瓣置换手术外,其余15例手术病人均顺利康复出院.术后远期随访无死亡,心功能全部恢复至Ⅰ级.复查超声心动图二尖瓣瓣口面积3.3-4.8 cm2,平均(3.78±0.52)cm2,均无明显反流,反流面积(0.45±0.22)cm2,左房、左室明显缩小[(左房径:术前(48.26±11.12),mm,术后(37.57±9.56)mm,P=0.028;左窜舒张末径术前(61.43±8.24)mm,术后(42.35±10.79)mm,P=O.008].结论 "缘对缘"技术基础上的腱索转移法治疗二尖瓣前叶脱垂,操作简单,可以取得良好的成形效果.     

Controversy in mitral valve repair,resection or chordal replacement?

Mitral valve plasty has superseded valve replacement as the standard technique for treating degenerative mitral valve prolapse. Quadrangular resection is considered the gold standard for posterior leaflet prolapse. Chordal replacement was first developed to treat the anterior leaflet and subsequently became widely used for the posterior leaflet, after which a new version of posterior leaflet resection was developed that did not involve local annular plication. In the era of the mini-thoracotomy, the premeasured loop technique is simple to adopt and is as durable as quadrangular resection. However, there is controversy surrounding whether resection or chordal replacement is the optimal technique. The resection technique is curative because it removes the main pathologic lesion. The disadvantage of the resection is that it can be complicated and often requires advanced surgical skills. In contrast, chordal replacement is not pathologically curative because it leaves behind a redundant leaflet. However, the long-term results appear to be equivalent in many reports. Functionally, chordal replacement retains greater posterior leaflet motion with a lower trans-mitral pressure gradient than quadrangular resection. Moreover, chordal replacement is simple and yields uniform results. The optimal technique depends on whether the anterior leaflet or posterior leaflet is involved, the Barlow or non-Barlow disease state, and whether a mini-thoracotomy or standard sternotomy approach is used. For mitral valve repair, the most superior and reliable technique for the posterior leaflet is resection using the newer resection technique with a sternotomy approach, which requires a skilled surgeon.     

Imbalanced chordal force distribution causes acute ischemic mitral regurgitation: mechanistic insights from chordae tendineae force measurements in pigs

BACKGROUND: Ischemic mitral regurgitation is caused by an imbalance of the entire mitral-ventricular complex. This interaction is mediated through the chordae tendineae force distribution, which may perturb several elements of the mitral valve apparatus. Our objective was to investigate the association between the mitral valvular 3-dimensional geometric perturbations and chordae tendineae force redistribution in a porcine model of acute ischemic mitral regurgitation. METHODS: In 9 pigs, acute ischemic mitral regurgitation was induced by repeated microembolization of the left circumflex coronary artery. Mitral leaflet coaptation geometry was determined by 2-dimensional echocardiography and reconstructed 3-dimensionally. Leading edge chordal forces were measured by dedicated miniature force transducers at control and during ischemic mitral regurgitation. RESULTS: During acute ischemic mitral regurgitation, there was a decreased tension of the primary chorda from the ischemic posterior left ventricular wall to the anterior leaflet (0.295 +/- 0.063 N vs 0.336 +/- 0.071 N [control]; P < .05). The tension of the chorda from the nonischemic anterior left ventricular wall to the anterior leaflet increased (0.375 +/- 0.066 N vs 0.333 +/- 0.071 N [control]; P < .05). In accordance, relative leaflet prolapse was observed at the ischemic commissural side, whereas there was an increase in the leaflet surface area at the nonischemic commissural side, indicating localized leaflet tethering. CONCLUSIONS: Acute ischemic mitral regurgitation due to posterior left ventricular wall ischemia was associated with focal chordal and leaflet tethering at the nonischemic commissural portion of the mitral valve and a paradoxical decrease of the chordal forces and relative prolapse at the ischemic site of the anterior mitral valve leaflet.     

Correction of anterior mitral prolapse. Results of chordal transposition.

From 1986 to 1992 102 mitral valve repairs were done for mitral regurgitation due to a degenerative disease. Forty-eight patients had an anterior prolapse or prolapse of both leaflets at initial presentation and underwent chordal transposition from the mural leaflet to the anterior leaflet. The corrective procedure was completed by polytetrafluoroethylene or pericardial posterior annuloplasty. Operative mortality was 2.9%, and follow-up (average 22 months) was 100% complete. There were three postreconstruction valve replacements (one earlier and two later) for a probability of freedom from reoperation of 91.5% +/- 5.2% at 3 years. Freedom from all morbidity was 85.5% +/- 5.5% at 3 years. Postoperative echocardiographic studies demonstrated a good mitral valve function: (1) Eighty-seven percent of patients presented no or mild residual regurgitation; (2) transmitral flow indexes were within the norm; (3) left ventricular outflow tract flow was normal in all patients. This study shows that chordal transposition is a safe and effective technique for prolapse of anterior or both leaflets and improves the chances of repair in patients with mitral degenerative disease.     

后叶腱索转移治疗二尖瓣前叶脱垂

目的总结采用后叶腱索转移术治疗二尖瓣前叶脱垂的临床经验和体会,探讨二尖瓣成形术的黄金时机。方法2004年10月至2008年10月治疗二尖瓣前叶脱垂16例,超声心动图检查诊断：二尖瓣前叶脱垂、腱索断裂10例,腱索延长4例,断裂合并延长2例;A1区域脱垂3例,A2区域脱垂6例,A3区域脱垂3例,合并A1、A2区域脱垂2例,A2、A3区域脱垂2例;均采用后叶腱索转移技术,其中1例合并冠心病患者同期施行冠状动脉旁路移植术。结果无手术死亡。出院前超声心动图检查提示：有少量反流2例,微量反流6例,无反流8例。出院后华法林抗凝治疗3个月。随访16例（100％）,随访1～46个月（22．0±3．5个月）,超声心动图提示：有少量反流3例,微量反流7例,无反流6例,效果优良。心功能Ⅰ级12例,Ⅱ级4例。出院前射血分数（EF）较术前降低（53．0％±3．4％vs．65．0％±4．2％,P=0．013）,术后随访时EF与术前比较差异无统计学意义（61．0％±2．1％vs．65．0％±4．2％,P=0．110）;出院前和随访时左心室舒张期末内径较术前明显缩小（50．0±3．2mm,47．0±2．8mmvs．58．0±6．5mm,P=0．031,0．020）;随访时心功能较术前明显改善（P=0．002）。结论后叶腱索转移是治疗二尖瓣前叶脱垂的有效方法,心瓣膜成形术的最佳时期是术前EF值大于60％、左心室轻度增大、心功能在Ⅲ级以上。     

线圈法人工腱索植入治疗二尖瓣关闭不全的近中期疗效分析

目的 总结线圈法人工腱索植入治疗二尖瓣脱垂导致的瓣膜关闭不全的临床经验。 方法 北京安贞医院心外科2008年1月至2011年8月应用线圈法人工腱索植入治疗二尖瓣关闭不全的患者共22例,男15例、女7例,年龄26～69 （53.1±8.5） 岁。心功能分级（NYHA） Ⅱ级6例,Ⅲ级16例。前叶腱索断裂14例,前叶腱索延长2例,前后叶腱索均有断裂4例,后叶腱索断裂2例。均合并重度以上二尖瓣反流,1例合并三房心,1例合并冠心病。左心室舒张期末内径49～67 （58.1±3.9） mm,射血分数（EF） 58%～69% （61.8%±6.1%）,心胸比率0.53±0.16。应用自制的腱索测量器,测量病变腱索邻近正常腱索的长度作为人工腱索的长度,根据瓣叶脱垂的范围,在测量器上制作人工腱索线圈数根,然后将其固定在相应乳头肌和脱垂瓣叶游离缘,常规进行瓣环成形。同期行三房心矫治术1例,冠状动脉旁路移植术1例。所有患者出院后华法林抗凝治疗3个月。 结果 无手术死亡,术后出现血红蛋白尿1例,伤口感染1例,经治疗后均痊愈。出院前超声心动图提示无反流或微量反流1例,微量反流21例。术后左心室舒张期末内径43～53 （48.3±2.1） mm,较术前明显改善。术后门诊随访4～39 （18.3±5.2） 个月,少量反流5例,无或微量反流17例。心功能分级（NYHA） Ⅰ级17例,Ⅱ级5例,较术前明显改善。 结论 线圈法人工腱索植入治疗二尖瓣脱垂所致的二尖瓣关闭不全,手术操作简单易行,近中期疗效满意。     

Surgical repair of mitral valve prolapse through a minimal right vertical infraaxillary thoracotomy

Abstract Background: Minimally invasive mitral valve surgery has been proven a safe and cosmetic alternative to the conventional median sternotomy approach. The aim of this study is to retrospectively evaluate the clinical outcome of mitral valve repair for leaflet prolapse through a minimal right vertical infraaxillary thoracotomy (RVIAT). Methods: From January 2003 to December 2011, 68 patients with mitral regurgitation (MR) due to leaflet prolapse underwent mitral valve repair through a RVIAT approach. There were 37 males and 31 females. The mean age of the patients was 37.8 ± 10.5 years. Of the 68 patients, 45 had posterior leaflet prolapse and 23 had anterior leaflet prolapse. Results: The mean incision length was 7.3 ± 1.8 cm (range 5.5 to 10.0 cm). Mitral valve repair technique included quadrangular resection with or without sliding repair (40 cases), edge to edge technique (six cases), artificial chordae (18 cases), chordal transfer (four cases), and ring annuloplasty was performed in all 68 patients. There was no severe morbidity and operative mortality. Echocardiography after operation demonstrated absence or trivial mitral regurgitation in 52 patients and mild regurgitation in 16 patients. During the 3 months ～8 years' follow-up period, one patient (1.5%) underwent mitral valve replacement through the median sternotomy due to recurrent severe MR. Other patients were in good condition. Conclusion: Surgical repair of mitral valve prolapse can be successfully performed through the RVIAT approach achieving excellent cosmetic and clinical results. (J Card Surg 2012;27:533-537).     

Replacement of Mitral Valve Posterior Chordae Tendineae with Expanded Polytetrafluoroethylene Suture: A Finite Element Study

A bstract Background and Aims : Expanded polytetrafluoroethylene (ePTFE) suture has been used clinically for replacement of ruptured mitral valve chordae tendineae. The purpose of this study was to assess mitral valve function after posterior chordal replacement with ePTFE suture. Methods : A three-dimensional finite element computer model of the mitral valve was used, which incorporated geometry, regional tissue thickness, collagen fiber orientation, and anisotropic material properties for the leaflets, interface, and chordae tendineae. To simulate chordal rupture, four marginal and four basal chordae were removed from the posterior leaflet. Chordal replacement was simulated using two elements with the physical and material properties of 2–0 ePTFE suture. Systolic loading pressures were applied. Results : The chordal rupture model demonstrated posterior leaflet prolapse, abnormal stress concentrations, potential regurgitation, and elevated chordal stress. Conversely, the chordal replacement model corrected the prolapse and returned chordal stress to normal levels. However, stress concentrations were shown at suture attachment points. Conclusions : This integrated mitral valve finite element model provides a tool to investigate the performance of the valve system. In this study, we have shown that 2–0 ePTFE suture replacement of ruptured posterior chordae tendineae returns the valve to a near normal state, in terms of leaflet stress and coaptation, and chordal stresses.     

Surgical techniques for the repair of anterior mitral leaflet prolapse

Myxomatous disease is the leading cause of mitral valve regurgitation in the developed world. Although posterior mitral leaflet (PML) prolapse is the most common cause of regurgitation and of repair, lesions of the anterior mitral leaflet (AML) are often considered beyond the possibilities of repair. The surgical anatomy and pathology of the AML and a precise terminology for the location of the lesions are described. The surgical maneuvers for commissural prolapse, chordal shortening, chordal replacement, leaflet resection, and annuloplasty are also described. The advantages and limitations of each maneuver are discussed. It is concluded that a flexible approach to the repair of the AML is necessary to adapt the best technique for each type of lesion. No particular technique can be applied systematically to all lesions. It is the author's contention that the majority of AML lesions can be repaired safely.     

"Adjustable" artificial chordal replacement for repair of mitral valve prolapse

Achieving a stable repair of mitral valve prolapse can be difficult in complex pathologies, and a 5% to 20% late reoperation rate exists with leaflet resection and reconstruction. During an 8-year period, prolapse was managed uniformly with "adjustable" Gortex (W. L. Gore & Associates Inc, Flagstaff, AZ) artificial chordal replacement and Carpentier ring annuloplasty (Edwards Lifesciences LLC, Irvine, CA), without leaflet resection. Artificial chords were placed initially in the papillary muscles, and then after ring annuloplasty they were adjusted to optimize length to the prolapsing segment(s). Of 52 patients with prolapse, 100% were repaired successfully with artificial chords. Operative mortality was 1.9%, and 4, 6, and 8-year survivals were 87%, 81%, and 71%, respectively. Only 1 of 52 patients (1.9%) experienced late failure, and this patient was re-repaired with artificial chords. Thus, "adjustable" artificial chordal replacement facilitates uniform repair of mitral valve prolapse with a low late failure rate.     

Simultaneous operation of WPW syndrome combined with mitral regurgitation caused by infective endocarditis

A case of WPW syndrome combined with mitral regurgitation caused by infective endocarditis underwent surgical division of accessory pathway and mitral valve replacement preserving posterior leaflet simultaneously. A 56-years old woman suffered atrial fibrillation with pseudo VT and cardiac failure caused by mitral regurgitation. Electro-physiological study (EPS) revealed accessory pathway in postero-lateral wall in left atrium and atrio-fascicular pathway like James bundle in AV node. ECHO cardiography showed mitral valve prolapse and severe regurgitation. Accessory pathway was divided surgically and deep freeze coagulation was followed. Perforation of anterior leaflet and chordal rupture of posterior leaflet caused by infective endocarditis were repaired by annuloplasty (Kay and McGoon method) at first, but regurgitation retained moderately. After re-clamping of aorta, mitral valve was replaced with prosthesis (SJM 29 mm) preserving posterior leaflet. Postoperative examination revealed division of accessory pathway and no regurgitation of mitral prosthesis.     

The "hybrid flip-over" technique for anterior leaflet prolapse repair

Repair of the anterior mitral leaflet or bi-leaflet prolapse is technically more demanding than repair of the posterior mitral leaflet. Although several techniques have been proposed for the repair of anterior mitral leaflet prolapse during bi-leaflet repair, practical challenges remain, including the determination of the appropriate length for artificial chords. Herein we describe a novel and reproducible technique for bi-leaflet mitral valve repair, including those with extensive anterior mitral leaflet prolapse.     

Valvuloplasty for anterior mitral leaflet prolapse due to infective endocarditis: report of 2 cases

We report 2 clinical cases of successful repair of an infected mitral valve with a broad-range prolapse of the anterior mitral leaflet (AML) with large vegetation. The chordal transfer technique was used in both cases, and autologous pericardium was transplanted in one case. There was neither residual mitral regurgitation nor recurrence of mitral valve infection. Chordal transfer is a useful technique for AML lesions of infective endocarditis if the corresponding area of the posterior ML remains normal, and even in the case of a broadly destroyed lesion of the AML, it is valuable to try to apply this technique with an autologous pericardial patch.     

Mitral valve repair for isolated prolapse of the anterior leaflet: an 11-year follow-up.

OBJECTIVE: Mitral valve insufficiency (MVI) because of involvement of the anterior mitral leaflet may pose additional risks for late outcome after mitral valve repair, because of more complex techniques. We retrospectively reviewed our experience in patients operated on for isolated anterior mitral leaflet prolapse approached by various techniques. METHODS: Between 1986 and 1997, 616 patients underwent mitral valve repair at our Institution. Isolated pathology of the anterior mitral leaflet was the cause of MVI in 84 patients (13.6%). Age ranged from 23 to 74 years (mean 50 +/- 14). Etiology of MVI was predominantly degenerative (57 patients, 67.8%), and the mechanism of the regurgitation was mainly due to a chordal rupture (58 patients, 69%). Annular dilatation was present in 75 patients (89.5%). A variety of surgical techniques were applied including chordal shortening (five patients, 5.9%), chordal transposition (three patients, 3.5%), artificial chordae (11 patients, 13%). Since 1992, however, the majority of procedures was performed using the 'edge to edge' technique (52 patients, 51.9%). Annular dilatation was treated mainly by means of a prosthetic ring (46 patients, 61.3%) whereas 18 patients (24%) underwent posterior annuloplasty using gluteraldehyde-treated native pericardium. RESULTS: Follow-up ranged from 3 to 122 months (mean 46 +/- 24 months). There were three hospital deaths (3.5%) and five late deaths (5.9%) for a Kaplan-Meier estimated survival of 87.6% at 8 years. Three patients underwent early reoperation within 30 days (3.5%), and six patients underwent late reoperation (7.1%), for a cumulative freedom from reoperation of 85.4% at 8 years. Seventy-four percent of the survivors (50 patients) are still in New York Heart Association Class I, and 92% of survivors (62 patients) have no or trivial (1+) residual mitral regurgitation at echocardiographic follow-up. CONCLUSION: In spite of the greater complexity, conservative surgery to correct anterior mitral valve prolapse pertains high success rate of long term. Recent technical modifications ('edge-to-edge' technique) may allow more expeditious and reproducible procedures with expected favorable influence of mitral valve repair applicability.     

Rescue surgical embolectomy for fatal pulmonary embolism in patient with intracranial hemorrhage

Left ventricular outflow obstruction may result from preserving the anterior leaflet after mitral valve replacement. A 79-year-old woman, who had a mitral valve replacement with the native mitral leaflets left intact 16 years before, was admitted to our hospital with severe dyspnea due to heart failure. Echocardiography showed systolic anterior motion of preserved anterior mitral leaflet, and continuous wave Doppler detected severe left ventricular outflow tract jets during systole without mitral chordal rupture. Surgical incising of the anterior mitral leaflet through the aortic root relieved the obstruction without removing the prosthetic mitral valve.     

Influence of anterior mitral leaflet second-order chordae on leaflet dynamics and valve competence

BACKGROUND: Chordal transposition is used in mitral valve repair, yet the effects of second-order chord transection on valve function have not been extensively studied. We evaluated leaflet coaptation, three-dimensional anterior mitral valve leaflet shape, and valve competence after cutting anterior second-order chordae. METHODS: In 8 sheep radiopaque markers were affixed to the left ventricle, mitral annulus, and leaflets. Animals were studied immediately with biplane videofluoroscopy and echocardiography before (Control) and after (Cut2) severing two anterior second-order "strut" chordae. Leaflet coaptation was assessed as separation between leaflet edge markers in the midleaflet and near each commissure (anterior commissure, posterior commissure). Anterior leaflet geometry was determined 100 milliseconds after end-diastole from three-dimensional coordinates of 13 markers. RESULTS: Anterior leaflet geometry changed only slightly after chordal transection without inducing mitral regurgitation. Leaflet coaptation times were 79+/-17 and 87+/-22 milliseconds at the anterior commissure; 72+/-21, 72+/-19 milliseconds at midleaflet, and 71+/-12 and 75+/-8 milliseconds at the posterior commissure (p = NS) for Control and Cut2, respectively. CONCLUSIONS: Cutting anterior second-order chordae did not cause delayed leaflet coaptation, alter leaflet shape, or create mitral regurgitation. These data indicate that transposition of second-order anterior chordae ("strut" chordae) is not deleterious to anterior leaflet motion per se.