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.     

Leaflet resection for the degenerative mitral valve regurgitation; early/long-term assessment

Leaflet resection for posterior leaflet prolapse has been a standard repair procedure with good longterm durability. The aim of this study was to review our experience of mitral valve repair, in which resection of the anterior and/or posterior leaflets was performed. Between October 1991 and December 2010, 172 patients with degenerative mitral valve regurgitation underwent mitral valve reconstruction,including 98 patients with the posterior leaflet prolapse, 47 patients with the anterior leaflet prolapse, 17 patients with both leaflets and 10 patients with the commissure prolapse. Most patients in this study were supposed to be caused by fibroelastic deficiency and we have not experienced systolic anterior motion after repair. The mean follow-up period was 8.7 ± 5.5 years. The freedom from reoperation rates at 15 years in 88.7 ± 5.3% of the anterior leaflet procedure, 96.6 ± 2.5% of the posterior leaflet, and 100% of both leaflets. The results of resection of a diseased prolapsed mitral leaflet have been promising so far. However, reoperation was required in 7 patients (4.1%) and reoperation rate was higher in patients with anterior prolapse and longer follow-up will evaluate precisely be benefit.     

Surgical treatment of active infective mitral valve endocarditis.

Although infective endocarditis is primarily treated conservatively with antimicrobial therapy, early surgical intervention is often mandatory when various complications arise. These include intractable heart failure, persistent uncontrollable infection, large mobile vegetations, peripheral embolism and prosthetic valve endocarditis. Optimal timing of surgical intervention in patients with infected heart valves results in reduced early and late mortality. In the context of healed infective endocarditis, mitral regurgitation is treated with mitral valve repair, which produces long-term results similar to those seen for treatment of degenerative mitral regurgitation. Mitral valve repair should also be considered for patients with mitral regurgitation due to active infective endocarditis. Superficial infection without valve destruction is the best candidate for valve repair. Discrete vegetations on the valve leaflets are excised along with underlying leaflet tissue (vegetectomy). Although valve lesions can be repaired by standard techniques, particular care (e.g., reinforcement with a pericardial patch) should be taken to avoid excess tension on the suture line. The feasibility of valve repair depends on the extent of tissue destruction. Large defects of the anterior leaflet, due to transmural infection or lesions that encompass greater than one-third of the entire posterior leaflet with annular abscess, are not amenable to repair. Also, the involvement of the aortic valve frequently necessitates valve replacement. Further, unstable preoperative hemodynamics leads to the decision to perform valve replacement immediately rather than complicate valve repair in an attempt to avoid prolonged operation time for life salvage. In the context of the feasibility of valve repair, timely surgical intervention and precise repair technique are essential.     

The double-orifice technique in mitral valve repair: a simple solution for complex problems

OBJECTIVE: The aim of this study is to report our results with the central double-orifice technique used for the treatment of complex mitral valve lesions. METHODS: The central double-orifice repair has been used in 260 patients (mean age, 56 +/- 14.3 years) over a period of 7 years. The mechanism responsible for mitral regurgitation was prolapse of both leaflets in 148 patients, prolapse of the anterior leaflet in 68, prolapse of the posterior leaflet with annular calcification or other unfavorable features in 31, and lack of leaflet coaptation for restricted motion or erosion of the free edge in 13. Degenerative disease was the cause of mitral regurgitation in 80.8% of the patients, rheumatic disease was the cause in 9.6%, endocarditis was the cause in 6.1%, and ischemic disease was the cause in 2.3%. RESULTS: Hospital mortality was 0.7%, and the overall survival at 5 years was 94.4% +/- 2.59%. Thirteen patients required a reoperation (2 early postoperatively and 11 late during the follow-up), for an overall freedom from reoperation of 90.0% +/- 3.37% at 5 years. Freedom from reoperation was lower in patients with rheumatic valve disease and in patients who did not undergo an annuloplasty procedure. CONCLUSIONS: The effectiveness and durability of the central double-orifice technique were assessed in this study. This type of repair can be a useful addition to the surgical armamentarium in mitral valve reconstruction.     

Tricuspid leaflet augmentation to eliminate residual regurgitation in severe functional tricuspid regurgitation

We describe a technique for treating severe functional tricuspid regurgitation (TR) when residual regurgitation cannot be eliminated with ring annuloplasty alone. The anterior leaflet and the anterior half of the posterior leaflet are augmented with an elliptic pericardial patch before implantation of a rigid annuloplasty ring. We successfully performed this procedure in 9 patients with severe TR due to severe leaflet tethering or short coaptation length and achieved complete elimination of TR with sufficient coaptation length in tricuspid valve leaflets for all patients.     

Post-repair coaptation length and durability of mitral valve repair for posterior mitral valve prolapse

Objective

Chordal placement with no or minimal leaflet resection has been suggested as the preferred technique for mitral valve repair for posterior leaflet prolapse, because it creates a longer coaptation zone. However, whether or not a long coaptation zone improves the durability of mitral valve repairs remains unclear.

Methods

We reviewed 119 patients with chronic degenerative mitral regurgitation including posterior middle scallop prolapse who underwent mitral valve repair between June 2004 and July 2008. We divided them into two groups according to post-repair coaptation length ≥8 mm (group A) or <8 mm (group B). We assessed whether coaptation length is associated with recurrent mitral regurgitation at 1 year after surgery and increase in the regurgitant jet area over 1 year.

Results

The group A had a lower incidence of recurrent mitral regurgitation (4.7 vs 9.2 %, p = 0.30), smaller increase in mitral regurgitant jet area over 1 year (0.29 vs 0.40 cm², p = 0.43), and higher 5-year freedom from recurrent mitral regurgitation (85.6 vs 76.1 %, p = 0.76), although the differences were not statistically significant. The multivariate analysis showed that large coaptation length tends to be associated with decreased recurrent mitral regurgitation at 1 year (odds ratio 0.02, 95 % confidence interval 0.00–3.67, p = 0.14).

Conclusions

This study did not confirm the association between coaptation length and durability of mitral valve repair for posterior middle scallop prolapse. However, there was a trend towards decreased recurrent mitral regurgitation with larger coaptation length.     

The isolated congenital mitral regurgitation due to a partial defect of the anterior leaflet

The isolated congenital mitral regurgitation (MR) is a rare anomaly. We have successfully treated a 7-year-old boy who had MR due to a partial defect of the anterior leaflet. Echocardiogram revealed moderate MR at the anterior leaflet as a result of its partial defect. Another MR was also detected at the coaptation zone of the 2 leaflets due to mild prolapse of the anterior leaflet. The mitral valve was approached via atrial septostomy and a partial defect (8 x 6 mm) was found near the postero-medial commissure of the anterior leaflet. Any chordae did not develop around the defect or subvalvular lesions. Other parts of the leaflet was seemed normal and any inflammatory or degenerative changes were not detected in the rest of the leaflets. We have done direct closure of the defect of the leaflet and also added annuloplasty at the posteromedial commissure by modified Kay method.     

Unusual mitral valve abnormalities complicating surgical repair of endocardial cushion defects

A review of 155 cases of surgically repaired endocardial cushion defects revealed 16 patients (10%) with additional unusual mitral valve abnormalities that complicated the surgical procedure. Eight patients had accessory mitral valve tissue that connected the anterior and posterior leaflets to form a double-orifice valve (Group I). In four (50%), the lesion was associated with intermediate atrioventricular canal and small left ventricle; all four died following repair. In the other four, it was associated with ostium primum defect; all survived and are well. A single papillary muscle in the left ventricle was present in six patients (Group II). Two had intermediate atrioventricular canal and both died postoperatively. The other four had complete endocardial cushion defect and three are well following the operation. Perforation of the valve leaflets was present in two patients with ostium primum (Group III). Both patients are well postoperatively. Modification of the surgical technique is required to effect satisfactory repair. The bridge connecting the posterior and anterior leaflets of the mitral valve should be left undisturbed. Otherwise, severe regurgitation may result. In patients with single papillary muscle and complete atrioventricular canal, repair may be accomplished by borrowing from the tricuspid portion of the anterior leaflet, rotating that part posteriorly, and partially closing the cleft. Small perforations of the mitral leaflet do not require closure and do not result in regurgitation. Echocardiographic and angiographic delineation of these abnormalities and thorough intraoperative exploration are important in avoiding pitfalls at the time of repair.     

Isolated tricuspid regurgitation due to atypical morphology of anterior-posterior leaflets in an adult: a case report and review of the literature.

A 73-year-old woman with congenital isolated organic tricuspid regurgitation was reported. She had neither the history of chest trauma nor rheumatic fever nor the evidence of infective endocarditis. The patient was successfully treated with a bioprosthetic valve replacement in tricuspid position. Operative findings revealed hypoplastic anterior leaflet and relatively large posterior leaflet. Structural anomaly of the valve, coaptation disorder due to the thickened valve leaflets, as well as enlarged valve ring and the occurrence of atrial fibrillation was thought to be the causes of massive regurgitation.     

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.     

Neochordal repair of the posterior mitral leaflet

BACKGROUND: Myxomatous mitral valve insufficiency is traditionally repaired by posterior leaflet quadrangular resection and reconstruction. A simplified repair technique without leaflet resection is described, and our initial experience is reviewed. METHODS: Thirty-nine consecutive patients with significant mitral regurgitation underwent repair since January 2000 by placement of expanded polytetrafluoroethylene sutures between the leading (coapting) edge of the posterior leaflet and the corresponding papillary muscle. An annuloplasty ring was placed, and no leaflet tissue was resected. Patient medical records were obtained and retrospectively reviewed. RESULTS: Twenty-five men and 14 women (median age, 61 years; range, 40-88 years) had their mitral valve repaired by a variety of surgical approaches, including robotic (18 patients), right thoracotomy (6 patients), and sternal (15 patients). Three patients have required valve replacement: 1 at the initial operation, 1 because of dehiscence of the annuloplasty ring, and 1 after subsequent rupture of a previously normal native chorda. At follow-up (median, 12 months), 92% (33/36) of the remaining patients had an intact mitral repair with no to mild regurgitation, 8.3% (3/36) of patients had moderate regurgitation, and 92% of all patients (36/39) were in New York Heart Association class I. There were no deaths. CONCLUSIONS: Myxomatous mitral regurgitation due to posterior leaflet insufficiency can be repaired without leaflet resection by placement of neochordae. This repair technique is effective and is readily accomplished by traditional and minimally invasive surgical approaches.     

Ischemia in three left ventricular regions: Insights into the pathogenesis of acute ischemic mitral regurgitation

BACKGROUND: Acute posterolateral left ventricular ischemia in sheep results in ischemic mitral regurgitation, but the effects of ischemia in other left ventricular regions on ischemic mitral regurgitation is unknown. METHODS: Six adult sheep had radiopaque markers placed on the left ventricle, mitral annulus, and anterior and posterior mitral leaflets at the valve center and near the anterior and posterior commissures. After 6 to 8 days, animals were studied with biplane videofluoroscopy and transesophageal echocardiography before and during sequential balloon occlusion of the left anterior descending, distal left circumflex, and proximal left circumflex coronary arteries. Time of valve closure was defined as the time when the distance between leaflet edge markers reached its minimum plateau, and systolic leaflet edge separation distance was calculated on the basis of left ventricular ejection. RESULTS: Only proximal left circumflex coronary artery occlusion resulted in ischemic mitral regurgitation, which was central and holosystolic. Delayed valve closure (anterior commissure, 58 +/- 29 vs 92 +/- 24 ms; valve center, 52 +/- 26 vs 92 +/- 23 ms; posterior commissure, 60 +/- 30 vs 94 +/- 14 ms; all P <.05) and increased leaflet edge separation distance during ejection (mean increase, 2.2 +/- 1.5 mm, 2.1 +/- 1.9 mm, and 2.1 +/- 1.5 mm at the anterior commissure, valve center, and posterior commissure, respectively; P <.05 for all) was seen during proximal left circumflex coronary artery occlusion but not during left anterior descending or distal left circumflex coronary artery occlusion. Ischemic mitral regurgitation was associated with a 19% +/- 10% increase in mitral annular area, and displacement of both papillary muscle tips away from the septal annulus at end systole. CONCLUSIONS: Acute ischemic mitral regurgitation in sheep occurred only after proximal left circumflex coronary artery occlusion along with delayed valve closure in early systole and increased leaflet edge separation throughout ejection in all 3 leaflet coaptation sites. The degree of left ventricular systolic dysfunction induced did not correlate with ischemic mitral regurgitation, but both altered valvular and subvalvular 3-dimensional geometry were necessary to produce ischemic mitral regurgitation during acute left ventricular ischemia.     

Neochordal repair of a double orifice mitral valve

Native double-orifice mitral valve is an exceedingly rare valvular abnormality. A 77-year-old patient was referred for a severe mitral regurgitation, and a double-orifice mitral valve with a central fibrous bridge was unexpectedly found. A flail anterior leaflet with 2 ruptured chordae was observed on the anterolateral mitral valve orifice, the leaflets on the posterior valve orifice were normally thin. Mitral valve repair was successfully performed with replacement of the 2 torn chordae by two 4/0 expanded polytetrafluoroethylene neochordae. We accordingly suggest that current mitral valve repair techniques remained a valuable option, even on central bridge double-orifice mitral valve regurgitation.     

Right ventricular reduction as an adjunct procedure in tricuspid valve repair

Functional tricuspid regurgitation secondary to mitral valve disease can not be attributed to the dilatation of the tricuspid annulus alone. Furthermore, geometrical changes of the right ventricle lead to tethering of the tricuspid valve leaflets and thereby to an incomplete leaflet coaptation. With this pathologic entity, conventional isolated tricuspid valve annuloplasty will presumably result in significant residual tricuspid regurgitation. The surgical goal should be the reduction of tricuspid annulus dilatation and annihilation of tethering forces on the tricuspid leaflets. In combination with conventional tricuspid valve annuloplasty, right ventricular reduction surgery, as demonstrated, may be effective in reaching these goals and hereby avoiding residual tricuspid regurgitation in this patient population.     

Systolic anterior motion of the mitral valve despite the sliding leaflet technique for repair of the mitral valve

We report a systolic anterior motion of the anterior mitral leaflet despite employing the sliding leaflet technique for repair of mitral valve regurgitation. A 65-year-old man with chronic, symptomatic mitral regurgitation due to ruptured chordae tendineae underwent mitral valve repair by quadrangular resection of the posterior leaflet and sliding leaflet technique with ring annuloplasty. After weaning from cardiopulmonary bypass, left ventricular outflow obstruction developed and transesophageal echocardiography demonstrated systolic anterior motion of the mitral valve and severe mitral regurgitation. Non-operative treatment resolved the outflow tract obstruction, systolic anterior motion and mitral regurgitation. We conclude that post-repair systolic anterior motion can still occur after the sliding plasty procedure and that medical treatment can successfully resolve systolic anterior motion and outflow tract obstruction in most patients.     

Valve reconstruction in the Heart Institute of São Paulo,Brazil

In the Heart Institute of University of S?o Paulo Medical School, between 1980 and 2000, were performed 712 mitral valve repair procedures, 39 aortic valve repairs and 469 tricuspid valve repairs. In our experience with mitral valve repair, the most performed techniques were quadrangular resection of the posterior leaflet, posterior annuloplasty with bovine pericardial sling and Carpentier ring annuloplasty. Quadrangular resection of the posterior leaflet is the technique of choice in mitral regurgitation due to degenerative disease, and repair is possible in 90% of the cases. Since 1994, we perform the quadrangular resection without ring annuloplasty, a modification in the technique called "Double Teflon" technique, with good results. Aortic valve repair is performed in specific situations. In congenital aortic insufficiency, we perform the suspention of the prolapsed leaflets in the comissures. In rheumatic aortic insufficiency, when we found leaflet retraction, we elongate the leaflets with bovine pericardial patchs. Our experience of aortic valve repair, between 1980 and 2000, consists of a small group of 39 patients. The results are satisfactory, but these techniques are feasible only in selected cases. Tricuspid insufficiency is generally a consequence of annular enlargement in patients with mitral valve disease and we prefer the De Vega annuloplasty in these cases. In cases with large annulus dilatation, we prefer to use the "Revuelta" or the "bicuspidization" techniques. In patients with previous tricuspid repair and annulus distortion, we prefer to use bovine pericardial sling or Carpentier ring annuloplasty.     

Mitral valve plasty for acute infective endocarditis; report of a case

A 68-year-old woman was admitted with congestive heart failure and septic shock associated with suspected mitral valve acute infective endocarditis. Echocardiography revealed vegetations attached to both mitral leaflets, prolapse of the posterior mitral leaflet and severe mitral regurgitation. Emergent surgery was performed. The anterior mitral leaflet displayed multiple vegetations. The entire anterior leaflet of mitral valve was replaced with pericardium. The posterior mitral leaflet of the middle scallop was prolapsed with an attached vegetation. Quadrangular resection was performed. A commissural reconstruction by sliding commissuroplasty for a prolapse of both anterior and posterior leaflets in the paracommissural area and autologous pericardial mitral annuloplasty was performed. Mitral regurgitation disappeared postoperatively, and the patient is now doing well as of 5 years postoperatively.     

Posterior mitral valve restoration for ischemic regurgitation

Chronic ischemic mitral regurgitation is traditionally a complex lesion to repair. Only restrictive annuloplasty has become an accepted strategy to avoid valve replacement, but results are unsatisfactory in some subgroups of patients. We describe an original technique that addresses the pathophysiologic mechanisms responsible for one of the most common subtypes of ischemic mitral regurgitation, ie, asymmetric tethering of the mitral leaflets after inferior myocardial infarction. The technique includes partial detachment of the posterior leaflet from the mitral annulus, annular plication, and posterior cusp plasty.     

Artificial chordae

Expanded polytetrafluoroethylene sutures have been used for replacement of chordae tendineae since 1985. They have been used for correction of prolapse of mitral and tricuspid valve leaflets as well as for resuspension of the papillary muscles during mitral valve replacement when the native chordae cannot be preserved to maintain continuity between the mitral annulus and papillary muscles. The sutures used were 5CV Gore-Tex for replacement of the chordae tendineae of the anterior leaflet and 6CV for the posterior leaflet and commissural areas of the mitral valve. Initially one suture was used to create two artificial chordae, but as experience increased, the technique was modified and multiple pairs of artificial chordae were created with a single suture by passing successively through the fibrous portions of the a papillary muscle and the free margin of the prolapsing segment of leaflet, and tying the tends together on the papillary muscle head. This technique creates artificial chordae that are interdependent and their lengths are self-adjusting when pressure is exerted on the leaflets. From 1985 to 1998, 288 patients had artificial chordae used during mitral valve repair for degenerative disease of the mitral valve. Prolapse of both leaflets was present in 51% of patients, isolated prolapse of the anterior leaflet in 28%, and posterior leaflet in 21%. The mean follow-up was 4.8 +/- 3.0 years and was complete. At 10 years, the freedom from mitral regurgitation >2+ was 88 +/- 6% and the freedom from reoperation was 92 +/- 2%. Failures of repair were unrelated to the artificial chordae. Gore-Tex sutures are an excellent material to replace chordae tendineae, appear to be free of adverse effects, and have become a valuable adjunct to the surgical armamentarium to treat mitral and tricuspid valve disease.     

Leaflet folding plasty for mitral valve repair

Objectives: Leaflet folding plasty was introduced for avoiding systolic anterior motion and coronary artery injury after mitral valve repair. We report the application and early outcome of this technique for mitral valve regurgitation. Methods: From January 1997 to January 2004,16 patients with mitral valve regurgitation were operated on using leaflet folding plasty. The group comprised 9 men and 7 women, with a mean age of 61.6 years. There were 15 patients with degenerative and 1 with ischemic mitral valve disease. The causes of mitral regurgitation were posterior mitral leaflet prolapse in 11 patients and commissural prolapse in 5 patients. Results: Mitral valve reconstruction could be performed in all patients. There were no perioperative deaths. Postoperative mitral regurgitation fell to 0.13±0.52 compared with 3.6±0.51 preoperatively. Systolic anterior leaflet motion was not observed in any patients after the procedure. The mean follow-up period was 22 months. There were no late deaths and reoperation was not required during follow-up. Conclusions: Early outcome of leaflet folding plasty for mitral valve repair was satisfactory. This technique may have advantages to accomplish mitral valve repair safely in patients with mitral regurgitation due to posterior or commissural prolapse.