Evaluation of the mitral valve leaflet morphology after mitral valve reconstruction with a concept "coaptation length index"

BACKGROUND: In clinical settings, information on morphology of mitral valve leaflet after mitral valve reconstruction is limited. METHODS: Between January 1996 and June 2000, 36 patients underwent mitral valve repair for mitral regurgitation (MR). The etiology of mitral insufficiency was prolapse, dilated annulus, and ischemia. Ring annuloplasty was performed in all cases. Mitral valve short-axis dimension (MVd), vertical distance between annular line and closing point (Vd), coaptation length (CL), and coaptation length index (CLI) were measured by two-dimensional transesophageal echocardiography for the present 11 cases. RESULTS: In 11 cases, residual MR, using a scale from 0 to 4, was 0 in 5 patients, 1 in 4 patients, 2 in 2 patients whose etiology of regurgitation was cardiomyopathy. MVd and Vd decreased significantly (38.7+/- 6.2 to 27.0 +/- 5.6 mm, 10.1 +/- 7.7 to 6.5 +/- 4.6 mm, respectively). CL and CLI increased significantly (6.4 +/- 2.4 to 11.6 +/- 4.6 mm, 0.16 +/- 0.06 to 0.44 +/- 0.21, respectively). Among those indices, only CLI has a statistically significant negative correlation with the degree of residual MR. CONCLUSION: Mitral valve ring annuloplasty produces the morphologic change of the mitral apparatus, especially increase of CLI, which may be one of the main factors in regulation of regurgitation.     

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.     

Long-term follow-up results after reconstruction of the mitral valve by leaflet advancement.

In this study, we discuss the clinical results of mitral leaflet advancement performed on 29 patients over the past 10 years and attempt to determine the indication. Preoperative diagnosis of mitral valve lesion consisted of mitral regurgitation in 21 patients and mitral stenosis in 8 patients. Mitral valve repair was applied to the anterior mitral leaflet in 2, the posterior mitral leaflet in 25, and bilateral leaflets in 2 patients. Reoperation was performed on 13 patients, and 1 patient died of renal failure immediately after reoperation. No reoperation was needed for 96.6% of the patients at 1 year, 89.5% at 5 years, 75.0% at 8 years, 63.8% at 10 years, and 52.6% at 15 years postoperatively. At reoperation, the repaired mitral leaflet was found to be calcified in 3 patients more than 9 years after the initial operation. Of the 12 survivors without reoperation, mitral stenosis associated with regurgitation was obvious in 6 patients. Of the 21 patients with preoperative mitral regurgitation, 90.0% showed no deterioration at 5 years, 79.7% at 8 years, and 69.1% at 10 years. On the other hand, for the 8 patients with mitral stenosis, the rates were 87.5% at 1 year, 62.5% at 5 years, 50.0% at 8 years, and 25% at 10 years. Our results suggest that mitral leaflet advancement shows satisfactory results in patients with mitral regurgitation but is not successful for patients with mitral stenosis in the long term because the repaired valve tends to be stenotic in the late postoperative period.     

Anterior leaflet resection of the mitral valve

Triangular resection is a reconstructive option for treatment of anterior leaflet mitral disease with segmental prolapse. In our experience, it is a safe and reproducible technique, associated with low rates of recurrent MR or need for reoperation, as well as decreased likelihood for systolic anterior motion after mitral repair. We review our experience with this technique over a 25-year experience with mitral valve reconstruction.     

Fracture of the Duromedics mitral valve housing with leaflet escape

We report a case of leaflet embolisation consequent upon a hemicircumferential fracture of the pyrolytic valve housing of a 29 mm mitral Duromedics Valve implanted for seven months. The clinical presentation is discussed and the literature on mechanical valve failure compared. Unlike pivoting disc valves where absent valve clicks equate with serious occluder dysfunction, valve sounds may persist with bileaflet valve malfunction due to the unimpeded movement of the normally functioning second leaflet. Whilst intrinsic structural failure is increasingly uncommon constant clinical awareness of its occurrence in a patient with a mechanical valve presenting with unexplained acute heart failure and pulmonary oedema, and prompt surgical intervention offers the best chance of survival. The aetiology of the primary fracture in this case remains unclear.     

Effect of glutaraldehyde fixation and valve constraint conditions on porcine aortic valve leaflet coaptation

In an investigation of the influence of glutaraldehyde fixation pressure and subsequent valve constraint on the coaptive characteristics of porcine aortic valves, 14 valves were examined, eight having been fixed at low pressure (congruent to 1 mm Hg) and six at high pressure (80 mm Hg). The coaptive ratios of the left and right coronary leaflets in the low-pressure-fixed valves showed a significant improvement over those of the same leaflets in the high-pressure-fixed valves. Inflation to 80 mm Hg results in a variable "peeling back" of the coaptive margins of the low-pressure-fixed valves but not of the high-pressure-fixed valves. Comparable coaptive ratios are therefore expected during full inflation of the unconstrained valves fixed both at low pressure and at high pressure. Constraining the low-pressure-fixed valves during inflation to simulate the effect of mounting on a rigid stent produced either a reduction or virtual elimination of this "peeling back" motion or in some instances a slight reversal of the effect, thus increasing the width of the coaptive margin. Hence it is expected that the stented low-pressure-fixed valve will manifest better coaptation than the high-pressure-fixed valve. Finally, the experimental findings of this study, combined with the improved mechanical function of the leaflet tissue already known to occur in the low-pressure-treated valves, provide a convincing case for valve fixation to be carried out under lower pressures.     

Double-breasted repair of the posterior mitral valve leaflet

The double-breasted repair of the posterior leaflet of the mitral valve is an alternative technique for correction of mitral regurgitation in selected patients. This new technique has the advantage of avoiding distortion of the posterior annulus and simplifies the repair, especially in complex posterior leaflet prolapse.     

Chordal replacement for leaflet prolapse in a posterior mitral valve with a calcified mitral annulus

Mitral annular calcification (MAC) is sometimes associated with Carpentier type 2 mitral valve regurgitation and is a challenge to repair. Complete annular decalcification and mitral valve reconstruction is considered the ideal treatment. This report demonstrates the success of chordal replacement and band annuloplasty without resection of the leaflet and MAC. We have followed the patient for 7 years postoperatively, with no progression of MAC and no regurgitation by echocardiography.     

Factors affecting mitral valve reoperation in 317 survivors after mitral valve reconstruction.

From a very heterogeneous group of 340 patients undergoing mitral valve reconstruction from 1969 through 1988, 313 hospital survivors were analyzed for factors affecting the occurrence of reoperative mitral valve procedures related to native mitral valve dysfunction. Follow-up was 100% and extended from 1 year to 20 years (mean follow-up, 7.2 years). Sixty-three patients (18.5% of the 340) required mitral valve reoperation at a mean postoperative interval of 6 years (range, 1 to 15 years). Incremental risk factors analyzed for the event late mitral valve failure included age, sex, preoperative New York Heart Association class, cause of valvular disease, pathophysiology of the mitral valve, previous mitral valve operation, mitral valve pathology, and estimation of mitral valve function at operation after repair. Mitral valve pathophysiology affected the actuarial freedom from mitral valve replacement (p = 0.023 [log-rank]). Actuarial freedom from mitral valve reoperation was 90% at 5 years and 80% at 8 years in patients who had either pure mitral regurgitation or isolated mitral stenosis compared with 80% and 72% at 5 and 10 years, respectively, in patients who had mixed mitral stenosis and regurgitation (p = 0.023). Patients undergoing late reoperation were younger (51.7 +/- 1.56 years [+/- the standard error of the mean]) than those not having reoperation (p less than 0.0003). Durability of the repair was less in patients with rheumatic heart disease (p less than 0.025) and greater in patients with ischemic heart disease (p less than 0.004). Seventy-three percent of patients undergoing reoperation had concomitant operations compared with 68% of those not having reoperation (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Mitral valve repair with anterior leaflet augmentation for rheumatic mitral valve disease

A 74-year-old male with congestive heart failure was referred to our hospital, and massive mitral regurgitation as well as aortic stenosis and regurgitation were detected by echocardiography. His mitral valve was successfully repaired with anterior leaflet augmentation with the equine pericardial patch followed by aortic valve replacement. Postoperative transthoracic Doppler echocardiography revealed no mitral regurgitation. The patient recovered uneventfully and was discharged on the 19th postoperative day. At 2 years and 2nd month after the operation, he is well without limitation of daily activities and any evidence of mitral regurgitation.