Unusual sequelae after percutaneous mitral valvuloplasty: a Doppler echocardiographic study.

Percutaneous mitral valvuloplasty is a promising new technique for the treatment of mitral stenosis, with a relatively low complication rate reported to date. To assess the sequelae of this procedure, Doppler echocardiographic studies were prospectively performed before and after percutaneous mitral valvuloplasty in a series of 172 patients (mean age 53 +/- 17 years). After balloon dilation, mitral valve area increased from 0.9 +/- 0.3 to 2 +/- 0.8 cm2 (p less than 0.0001), mean gradient decreased from 16 +/- 6 to 6 +/- 3 mm Hg (p less than 0.0001) and mean left atrial pressure decreased from 24 +/- 7 to 14 +/- 6 mm Hg (p less than 0.0001). Although most patients were symptomatically improved, six (4%) were identified who had unusual sequelae evident on Doppler echocardiographic examination immediately after percutaneous mitral valvuloplasty. These included rupture of a posterior mitral valve leaflet, producing a flail distal leaflet portion with severe mitral regurgitation detected on Doppler color flow mapping (n = 1); asymptomatic rupture of the chordae tendineae attached to the anterior mitral valve leaflet with systolic anterior motion of the ruptured chordae into the left ventricular outflow tract (n = 1); a double-orifice mitral valve (n = 1); and evidence of a tear in the anterior mitral valve leaflet (n = 3), producing on both pulsed Doppler ultrasound and color flow mapping a second discrete jet of mitral regurgitation in addition to regurgitation through the main mitral valve orifice. All six patients made a satisfactory recovery and none has required mitral valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)     

Differentiating clinical and echocardiographic characteristics of chordal rupture detected in patients with rheumatic mitral valve disease and floppy mitral valve: impact of the infective endocarditis on chordal rupture.

AIMS: We aimed to compare the clinical and echocardiographic correlates of chordal rupture in patients with rheumatic mitral valve disease and floppy mitral valve. METHODS AND RESULTS: The study group comprised of 224 patients who underwent transthoracic and transesophageal echocardiography because of the severe mitral regurgitation. Chordal rupture was detected in 58 (25.9%) out of the 224 patients, in 33 out of the 83 (39.7%) patients with floppy mitral valve, and in 25 out of the 141 (17.7%) patients with rheumatic mitral valve disease. Chordal rupture was more frequently associated with anterior leaflet (80%) in patients with rheumatic mitral valve disease, and posterior leaflet (72.7%) in patients with floppy mitral valve (p<0.05). Univariate correlates of chordal rupture were age, male sex, posterior mitral leaflet thickening and chordal elongation in patients with floppy mitral valve (p<0.05), and chordal shortening (p<0.0001) and infective endocarditis involving mitral anterior leaflet (p<0.05) in rheumatic group. Independent predictors of chordal rupture were age (>50 years), posterior mitral leaflet thickness (> or =0.45cm), and male sex (p<0.05) in patients with floppy mitral valve while infective endocarditis involving mitral anterior leaflet (p<0.05) in patients with rheumatic mitral valve disease. Patients with chordal rupture due to floppy mitral valve had an older age (p<0.0001), a male dominance, longer mitral leaflets and chordae, and a larger mitral annulus circumference (p<0.05) as compared to those with rheumatic chordal rupture. Despite the comparable severity of mitral regurgitation and left atrial diameters between the two groups of chordal rupture (p>0.05), functional class and pulmonary artery systolic pressure were higher, and atrial fibrillation, acute deterioration, infective endocarditis, mitral leaflet rupture and need for mitral valve surgery in the 3 months were more frequent in rheumatic chordal rupture subgroup (p<0.05). CONCLUSION: Chordal rupture seems to be more frequently associated with anterior mitral leaflet in rheumatic mitral valve disease, whereas it was the posterior leaflet in floppy mitral valve. Chordal rupture was related to male sex, older age, posterior leaflet thickening, and chordal elongation in patients with floppy mitral valve. However, infective endocarditis, acute deterioration, and need for early mitral surgery were more frequent in patients with rheumatic chordal rupture.     

Echocardiographic equivalents of a flail mitral leaflet

Echocardiograms were performed in 11 patients with symptomatic mitral regurgitation. The cause of the regurgitation, determined at the time of mitral valve replacement in 9 of the 11 patients, was either torn chordae tendineae or an avulsed papillary muscle head. Flail mitral leaflet was secondary to infective endocarditis in seven patients and to coronary heart disease in two patients; in the other two patients the cause of the flail leaflet was not determined. Echocardiograms from the 11 patients exhibited at least one of four distinct patterns: systolic left atrial echo, coarse diastolic fluttering of the anterior leaflet, paradoxical movement of the posterior leaflet throughout the cardiac cycles or early diastolic fluttering of the posterior leaflet. The last pattern was noted in two patients who refused surgery and in six patients who had mitral valve replacement. Although early diastolic fluttering of the posterior leaflet has not previously been reported to be indicative of a flail leaflet, it was the most frequent pattern observed in those with an untethered posterior leaflet (eight of nine patients). Five of the 11 patients had one of the four patterns, and the remaining 6 had at least two. The specific echocardiographic abnormalities were not related to the cause or severity of the mitral regurgitation but were determined by the location of the tear and the portion of the flail leaflet traversed by the ultrasonic beam. These patterns appear to represent an echocardiographic spectrum characteristic of a flail mitral leaflet. Detection of any of the four patterns in the presence of mitral regurgitation suggests torn chordae tendineae.     

Anterior leaflet procedures during mitral valve repair do not adversely influence long-term outcome

Objectives. This study was done to assess the impact of anterior mitral leaflet reconstructive procedures on initial and long-term results of mitral valve repair.Background. It has been suggested that involvement of the anterior leaflet in mitral valve disease adversely affects the long-term outcome of mitral valve repair. Our policy has been to aggressively repair such anterior leaflets with procedures that include triangular resections in some cases.Methods. From June 1979 through June 1993, 558 consecutive Carpentier-type mitral valve repairs were performed. The anterior mitral leaflet and chordae tendineae were repaired in 156 patients (mean age 58 years). The procedures included anterior chordal shortening in 78 patients (50%), anterior leaflet resections in 44 (28%), resuspension of the anterior leaflet to secondary chordae in 42 (27%) and anterior chordal transposition in 27 (17%). Concomitant cardiac surgical procedures were performed in 75 patients (48%).Results. The operative mortality rate was 2.5% (2 of 81) for isolated mitral valve anterior leaflet repair and 3.8% (6 of 156) for all mitral valve anterior leaflet repair. Freedom from reoperation at 5 and 10 years was, respectively, 89.7% (n = 160) and 83.4% (n = 24) for the entire series of 558 patients, 91.9% (n = 51) and 81.2% (n = 10) for patients with anterior leaflet procedures, 88.8% (n = 109) and 84.4% (n = 14) for patients without anterior leaflet procedures and 91.7% (n = 118) and 88.9% (n = 18) for patients without rheumatic disease. Logistic regression showed that rheumatic origin of disease (odds ratio 2.99), but not anterior leaflet repair, increased the risk for reoperation.Conclusions. These results demonstrate that expansion of mitral valve techniques to include anterior leaflet disease yields immediate and long-term results equal to those seen in patients with posterior leaflet disease.     

Repair of rheumatic mitral lesions by transfer of a segment of the posterior valve with its chordae onto the anterior valve

Since 1981, 100 patients have undergone mitral valve repair alone or in association with aortic or tricuspid valve surgery. The basic technique used was that described by Carpentier. However, in 13 of these patients, the repair was performed by a technical innovation consisting in transferring a one to two centimetres segment of the posterior leaflet with its chordae to the anterior leaflet. The lesions in which this particular technique was required were extensive chordal rupture of the anterior leaflet (5 cases), localised retraction of the surface of the anterior leaflet (2 cases), and perforation near the valve free edge due to endocarditis (1 case). The valvular disease was due to rheumatic fever in all cases. None of the patients had active endocarditis. The age of the patients varied from 4 to 60 years. Eight patients were under 15 years of age. Postoperative echocardiography and pulsed Doppler studies showed results comparable to the other patients who had undergone mitral valve repair although the valvular lesions were more severe in this particular group of patients. Only one patient had a poor operative result and had to be reoperated.     

Comparison of accuracy of transesophageal versus transthoracic echocardiography for the detection of mitral valve prolapse with ruptured chordae tendineae (flail mitral leaflet)

The accuracy of transesophageal echocardiography was compared with that of transthoracic echocardiography in the detection of ruptured chordae tendineae (flail mitral leaflet) in 27 patients with mitral valve prolapse (MVP) who underwent valve repair or replacement for mitral regurgitation. Confirmation of the presence of ruptured chordae resulting in a flail leaflet was available at surgery in all cases. The echocardiographic studies were read blindly by 2 independent observers with any differences resolved by a third. Mean (+/- standard deviation) age was 63 +/- 13 years. Men (n = 20) outnumbered women (n = 7) (p less than 0.02), and tended to be younger (p = 0.06). Flail leaflets were identified in 20 of 27 patients. In 1 patient, both leaflets were involved and in the remaining 19 patients posterior leaflets (15 patients) were more frequently affected than anterior leaflets (4 patients). Transesophageal echocardiography correctly identified all 20 patients with flail leaflets, but 1 false positive study occurred among the 7 patients without a flail leaflet. In contrast, transthoracic echocardiography identified only 12 of 20 patients with flail leaflets, with no false positive studies. Transesophageal echocardiography was more accurate, correctly classifying 26 of 27 (96%) cases versus 19 of 27 (70%) by the transthoracic approach (p less than 0.01). This study suggests a higher incidence of chordal rupture to the posterior leaflet in patients with MVP and demonstrates improved accuracy of transesophageal over transthoracic echocardiography in the detection of flail leaflets.     

Troublesome factors in mitral valve repair for mitral valve regurgitation

Limitations in the long-term results of medical treatment for mitral regurgitation are well recognized, but the advances in its surgical repair have produced good results. Therefore, early surgical intervention has been the focus of treatment in Europe and America. Increased surgical intervention depends on the development of technical skills in mitral reconstruction. This study investigated presurgical factors making surgical reconstruction difficult in 103 patients who underwent mitral operations performed from April 1994 to September 1997 in our hospital. Records were reviewed retrospectively for etiology, type of operation, and the immediate result of operation. The etiology of mitral regurgitation was prolapse in 65 patients (63%), restriction in 14, normal in 11, infectious endocarditis in 10, and others in 3. The type of prolapse involved the anterior leaflet in 22 patients (34%), posterior in 28 (43%), and both leaflets in 15 (23%). Valve repair was attempted in 74 patients, of which 16 were switched to valve replacement during operation. These included anterior leaflet prolapse in 9 patients, posterior leaflet in 1, both leaflets in 3, restriction in 2 and infectious endocarditis in 1. The success rate for reconstruction of anterior leaflet prolapse was not high. The cause of mitral regurgitation was mostly prolapse of the mitral valve, in our country as well as in Europe and America. Prolapsed posterior leaflet is much more common in Europe and America, and there is a high success rate reported for its valve reconstruction. In contrast, this study cannot recommend earlier surgical intervention because of difficult repair for anterior leaflet prolapse.     

Long-term site-related differences in the progression and regression of the idiopathic mitral valve prolapse syndrome.

The natural history of uncomplicated mitral valve prolapse (MVP) is not clearly understood. To determine the site-related differences in regression and progression of MVP, 112 patients with idiopathic MVP were enrolled in this echocardiographic follow-up study. Cardiovascular complications, including dysarrhythmias (n = 3, 2.7%), overt congestive heart failure (n = 4, 3.6%), progression of mitral regurgitation over one grade (n = 28, 25.0%), newly confirmed chordal rupture (n = 1, 0.9%), and surgical repair (n = 2, 1.8%), were observed in these patients during a follow-up period of 1-13 years (mean, 4.0 +/- 2.8 years). Multivariate analysis and Kaplan-Meier analysis revealed that posterior leaflet prolapse and significant mitral regurgitation (grade >/=2) were considerable risks for cardiovascular complications. Regression of MVP was seen in 17 (18.7%) of the anterior prolapse patients; however, new prolapse was observed in 40 (35.7%) patients, mainly in posterior prolapse patients. These results suggest that site-related differences exist in uncomplicated MVP prognosis and that MVP in the posterior leaflet has a poor outcome compared to that in the anterior leaflet.     

Color Doppler echocardiographic evaluation of patients with a flail mitral leaflet

Chordal rupture with a subsequent flail mitral valve leaflet is now the most common cause of pure mitral regurgitation. To describe the Doppler color flow findings in flail mitral leaflet and the determinants of these findings, Doppler color flow mapping and conventional Doppler echocardiography were performed in 31 consecutive patients presenting with a flail mitral leaflet. In the 23 patients with a posterior flail leaflet, a distinctive highly eccentric and turbulent jet directed toward the posterior wall of the aorta was noted. In the eight patients with an anterior flail leaflet, a jet directed toward the posterolateral left atrial wall was noted. Maximal regurgitant jet area was significantly larger in patients with a flail anterior leaflet (13.1 +/- 3.0 cm2) than in those with a flail posterior leaflet (5.8 +/- 3.0 cm2, p = 0.0001). Maximal jet area to left atrial ratio was also significantly higher in those with a flail anterior leaflet (0.56 +/- 0.16) than in those with a flail posterior leaflet (0.27 +/- 0.17, p = 0.0006). When systolic left atrial velocities encoded as red were incorporated into the maximal jet area measurement, 7 of the 8 patients with an anterior flail leaflet had a jet area greater than 8 cm2, consistent with severe mitral regurgitation, compared with 13 of the 23 patients with a flail posterior leaflet. There was no correlation between jet area or jet area to left atrial ratio and any hemodynamic variable. Patients with acute mitral regurgitation exhibited a trend toward smaller jet areas, but this did not reach statistical significance. Regurgitant fraction calculated from pulsed Doppler recording of mitral and aortic flow was consistent with moderately severe or severe mitral regurgitation in all cases and averaged 70%. Thus, patients with a flail mitral valve leaflet have distinctive Doppler color flow findings. A highly eccentric and turbulent jet directed posteriorly to the aorta may contribute to a systematic underestimation of severe mitral regurgitation by conventional Doppler color flow criteria. The use of pulsed Doppler ultrasound to calculate regurgitant fraction in patients with a flail mitral valve leaflet may be helpful in reliably assessing the degree of mitral regurgitation.     

Echocardiographic analysis of posterior mitral leaflet movement in mitral stenosis.

Echocardiographic analysis of the movement of the posterior mitral valve leaflet in 60 patients with lone mitral stenosis, 35 patients with aortic stenosis, and 18 patients with aortic and mitral stenosis showed a spectrum of initial posterior mitral valve leaflet movement in early diastole. The classical anterior movement was seen in 36 out of 60 patients with mitral stenosis (60%), and 8 out of 16 patients with aortic and mitral stenosis (50%). Normal posterior movement was present in all patients with lone aortic stenosis but was also seen in 10 patients (17%) with mitral stenosis and 6 patients (33%) with aortic and mitral stenosis. The remaining patients with mitral stenosis or aortic stenosis and mitral stenosis showed a biphasic type of initial movement. Patients with anterior movement had a mean calculated mitral valve area from cardiac catheterisation significantly smaller than the rest (P less than 0.001), but neither biphasic nor posterior movement excluded severe mitral stenosis. The distinction between patients with mitral stenosis and initial movement of the posterior mitral valve leaflet and patients with left ventricular discompliance is possible when there is sinus rhythm. Late diastolic anterior movement of the posterior mitral valve leaflet during atrial contraction is diagnostic of true mitral stenosis.     

Extension of calcific deposits in the anterior mitral valve leaflet and mitral valve stenosis severity. Use of 2D Echo parasternal long-axis view

To evaluate the role of the extent of calcific deposits on the anterior mitral leaflet in predicting the severity of mitral valve stenosis, two-dimensional echocardiography (2D Echo) and heart catheterization data were analysed in 62 patients with mitral valve stenosis, pure or associated with trivial valve regurgitation. 50 patients had technically adequate 2D Echo. Of these, 28 had pure mitral valve stenosis. The mitral valve area was estimated from the parasternal short-axis 2D Echo projection. Using the parasternal long-axis projection, calcium deposits location and extension on the anterior mitral leaflet was examined. Patients were subdivided into the following groups: Group 0 (absence of calcium deposits = 19 patients), Group 1 (calcium on distal third of the leaflet = 19 patients), Group 2 (calcium on mid and distal segments = 11 patients), Group 3 (calcium on the entire leaflet = one patient). The extension of calcium deposits in long-axis projection was contrasted with 2D Echo mitral valve area in the 50 mitral valve patients. 2D Echo and heart catheterization derived mitral valve area were compared to each other in the 28 patients with pure mitral valve stenosis. 2D Echo mitral valve area was greater in Group 0 patients (1.8 +/- 0.4 cm2) than in Group 1 (1.4 +/- 0.4 cm2) and in Group 2 (1.1 +/- 0.3 cm2) (p less than 0.001 between the three groups). Calcific deposits were present on the anterior mitral leaflet in 30/31 patients with 2D Echo mitral valve area less than or equal to 2 cm2. However, of the 19 patients of Group 0, 13 had moderate and one severe mitral valve stenosis. In the 28 patients with pure mitral valve stenosis, 2D Echo mitral valve area was excellently correlated with Gorlin's derived mitral valve area (r = 0.90). However, in patients with extensive calcification of the anterior mitral valve leaflet (Group 2), 2D Echo mitral valve area was significantly greater than the Gorlin's derived area (1.08 +/- 0.20 cm2 versus 0.68 +/- 0.17 cm2; p less than 0.001). In four patients of Group 2, the mitral valve stenosis was moderate by 2D Echo grading and severe by heart catheterization data. Our data suggest that the study of extension of calcific deposits on the anterior mitral valve leaflet may be a complementary aid in quantifying mitral valve stenosis to the 2D Echo mitral valve area estimate, especially when the valve is severely calcified.     

Comparison of cardiac findings in patients with mitral valve prolapse who die suddenly to those who have congestive heart failure from mitral regurgitation and to those with fatal noncardiac conditions.

Sudden death occurs in a small but important subset of patients with mitral valve prolapse (MVP). Clinical criteria for identifying patients at risk for sudden death have been elusive. To determine if certain morphologic characteristics were present in hearts from patients with sudden cardiac death and MVP, autopsy hearts from persons with sudden death and isolated MVP who were previously asymptomatic or had a history of cardiac arrhythmias (n = 27) were compared with (1) hearts from patients with congestive heart failure (CHF) and mitral regurgitation (MR) secondary to MVP (n = 14), and (2) hearts from persons dying from non-cardiac causes in which MVP was an incidental finding (n = 19). Patients who died suddenly were younger than both patients with MR/CHF and incidental cases (37 +/- 10 vs 65 +/- 16 and 58 +/- 21 years, respectively, p less than 0.001). Mitral valve annular circumference, anterior and posterior mitral valve leaflet lengths, posterior mitral valve thickness, and presence and extent of endocardial plaque were greater in hearts from patients with sudden death than hearts from those with incidental MVP. Hearts from patients with MR/CHF weighed significantly more, had greater left and right atrial cavity sizes and left ventricular cavity diameter than hearts from both sudden death and incidental cases.     

Mitral regurgitation following mitral balloon valvotomy. Differing mechanisms for severe versus mild-to-moderate lesions

BACKGROUND. This study was designed to evaluate the incidence and mechanisms of mitral regurgitation following mitral balloon valvotomy (MBV) in 40 consecutive patients with symptomatic tight pliable mitral stenosis. METHODS AND RESULTS. Transthoracic echocardiography with color flow mapping was performed before and 24 hours after the procedure. Patients who developed significant mitral regurgitation following MBV also underwent transesophageal echocardiography. The relation between increased mitral regurgitation and both valvular morphology and procedure-related factors was examined. Gorlin mitral valve area increased from 0.81 +/- 0.3 to 1.95 +/- 0.7 cm2 (p less than 0.001). No patient had more than 2+ mitral regurgitation by angiography and color Doppler prior to MBV. There was a moderate correlation between Doppler and angiographic increase in mitral regurgitation (r = 0.73, p less than 0.0001). By Doppler criteria 33 patients had no (n = 6) or mild (n = 27) increase in mitral regurgitation (group 1), and seven developed significant new mitral regurgitation (group 2). Baseline clinical, echocardiographic, and procedure-related data for the two groups were similar. Multiple regression analysis did not select any individual valve characteristic (valvular thickening, mobility, calcification, and subvalvular disease), total echocardiographic score, balloon diameter, or ratio of balloon to mitral annular diameter as disruption with a torn anterior or posterior mitral leaflet in six and a ruptured papillary muscle in one. Two of these patients have required mitral valve replacement (6 and 9 months following the procedure), whereas the remainder are significantly symptomatic. By contrast, mitral regurgitation in group 1 either occurred at the site of commissural split (n = 20) or was associated with prolapse of the anterior mitral leaflet (n = 6). CONCLUSIONS. Thus, severe new mitral regurgitation following MBV is due to noncommissural tearing of the mitral leaflet and confers an adverse long-term prognosis. A mild increase in mitral regurgitation following MBV is frequent and occurs at the site of commissural split or is associated with prolapse of the anterior leaflet. Furthermore, in this study, an increase in mitral regurgitation could not be predicted from any valvular or procedure-related factor.     

Early outcome with the Alfieri mitral valve repair

OBJECTIVES: Mitral regurgitation in cases of prolapse of the anterior leaflet, posterior leaflet with calcified annulus, or prolapse of both leaflets is thought to be difficult to repair. The Alfieri repair has been developed to address these conditions. METHODS: Seven patients (four men and three women, mean age 71 +/- 9 years) underwent the Alfieri repair for mitral regurgitation at Austin and Repatriation Medical Centre between January 1999 and December 1999. The mechanism of mitral regurgitation was prolapse of the posterior leaflet with calcified annulus in one patient, prolapse of the anterior leaflet in two, and prolapse of both leaflets in four. Mitral regurgitation before operation was severe in all patients. The Cosgrove ring was used in all patients. Four patients underwent combined operation, coronary artery bypass surgery in three and tricuspid annuloplasty in one. RESULTS: There was no hospital death. Two patients had postoperative complications, transient ischemic attack in one patient and rapid atrial fibrillation in one. The mean hospital stay was 11.3 +/- 8.7 days. Mitral regurgitation after operation was mild in five patients and trivial in two. Mean pressure gradient of the transmitral valve was 4.0 +/- 1.4 mmHg. CONCLUSIONS: The Alfieri mitral valve repair is a simple and satisfactory technique to repair mitral regurgitation in selected patients. Long-term follow-up is required to evaluate the durability of this technique.     

Eight-year experience of combined valve repair for mitral regurgitation and maze procedure

BACKGROUND AND AIMS OF THE STUDY: Although atrial fibrillation (AF) is often associated with severe mitral regurgitation (MR), a simultaneous maze procedure for AF associated with repair of MR remains controversial. In this study, mid-term results of combined mitral valve repair and the maze procedure were examined. METHODS: Between May 1992 and April 2001, 85 patients (61 males, 24 females) underwent valve repair for MR and the maze procedure. Mean age at surgery was 61.8+/-9.1 years; mean follow up was 4.7+/-2.3 years. Valve lesions were anterior in 26 patients (31%), posterior in 31 (36%), anterior + posterior in 23 (27%), and simple dilated annulus in five (6%). Chordal replacement with expanded PTFE sutures was performed in 40 patients (47%), and leaflet resection in 41 (48%). Ring annuloplasty was also applied in 61 patients (72%). Associated procedures were tricuspid valve annuloplasty in 33 (36%), coronary artery bypass grafting in four, atrial septal defect closure in two, aortic valve repair in one, and resection of abnormal septum in the left atrium in one. RESULTS: There was one hospital death (1%), and one late death (1%). Reopening the chest for bleeding was necessary in six cases (7%). One thromboembolic episode was detected during follow up (0.25%/patient-year). Reoperation for MR was performed in three patients (4%). Actuarial event-free survival rate was 90.0+/-6.4% at eight years. Sinus rhythm was regained in 68 patients (81%), and atrial A-wave was detected in 57 (68%) by pulsed Doppler study. Postoperative left ventricular diastolic and systolic dimensions were significantly (p = 0.001 and p = 0.017) smaller in patients who restored sinus rhythm than in those who did not (48.6+/-4.6 versus 54.6+/-4.7 mm, and 33.0+/-6.0 versus 38.1+/-6.9 mm). CONCLUSION: Combined mitral valve repair for MR and the maze procedure showed satisfactory midterm results. Postoperative sinus rhythm conversion by the maze procedure may reduce left ventricular size, and the incidence of thromboembolic episodes in mitral valve repair.     

Surgical treatment for mitral regurgitation: mid-term outcome following mitral valve repair

Mid-term results of mitral valve repair for mitral regurgitation were evaluated in 173 consecutive patients (mean age 53 years, 107 males, 66 females) treated from July 1991 to March 1998. Pathological causes of the mitral valve disease were degenerative in 118 patients, infective endocarditis in 25, rheumatic in 13, and ischemic in 8 (ischemic cardiomyopathy in 7). The principal technique was chordal replacement with expanded polytetrafluoroethylene sutures for prolapse of the anterior leaflet, and Carpentier's sliding leaflet technique for prolapse of the posterior leaflet. Most patients received ring annuloplasty with a rigid ring and flexible band (physiological remodeling annuloplasty). Intraoperative transesophageal echocardiography was used after 1993. There were 7 operative deaths (4%) and 7 mitral valve replacements (4%) during the same operation. Successful repair was achieved in 96% of patients with mitral regurgitation. Mean follow-up was 35 months (range 2 to 78 months). Survival at 6 years was 85 +/- 10% of all patients, 98 +/- 2% in degenerative cases. Six patients required reoperation (1.2%/patient-year) and mean time interval between initial operation and reoperation was 33.1 months. Four patients with atrial fibrillation had thromboembolic events (0.8%/patient-year). There were no anticoagulant-related complications. Freedom from reoperation and all valve-related event at 6 years was 88 +/- 6% and 84 +/- 6%. Late postoperative Doppler echocardiography revealed satisfactory results in 93% of the patients. Mitral valve repair using chordal replacement, sliding plasty and ring annuloplasty provides excellent mid-term results.     

Transesophageal echocardiography as predictor of mitral valve repair

BACKGROUND AND AIM OF THE STUDY: Mitral valve repair has recently emerged as the treatment of choice in patients presenting with insufficiency due to valve prolapse. The study aims were to evaluate: (i) the clinical presentation in a consecutive series of patients with mitral valve prolapse undergoing surgical repair; (ii) the correlation between pre- and intraoperative echocardiographic features and surgical findings in these patients; and (iii) whether clinical and echocardiographic data may predict surgical outcome. METHODS: Between March 1997 and May 2000, 152 patients (110 men, 42 women; mean age 59+/-13 years) were recruited into the study. All patients had myxomatous mitral valve disease causing severe regurgitation and underwent systematic examination by transesophageal echocardiography (TEE) for clear delineation of the three scallops of the posterior leaflet and juxtaposed segments of the anterior leaflet. RESULTS: In 119 patients (78%) a flail valve was documented by TEE and confirmed on surgical inspection; an anterior leaflet chordal rupture was not visualized by TEE in one case. In 15 cases (10%) there was flail of the anterior leaflet, and in 105 cases (69%) flail of the posterior leaflet. A bileaflet complex prolapse without chordal rupture was found in 32 cases. On the basis of TEE evaluation, mitral valve replacement was performed electively in 10 patients (7%); the other 142 (93%) underwent mitral valve repair. Adequate repair was obtained in 93% of cases; residual mitral regurgitation (eight cases; grade 3+) and mitral stenosis (one case) were documented by intraoperative TEE, and nine patients (6%) underwent valve replacement. CONCLUSION: The majority of patients with myxomatous mitral valve prolapse and severe regurgitation undergoing valve repair have chordal rupture of the posterior mitral leaflet, a condition in which results of valve repair are excellent. TEE provides a powerful means to define the mechanisms of mitral regurgitation and to identify the suitability of patients for valvuloplasty.     

Failure mechanics of mitral valve chordae tendineae

BACKGROUND AND AIM OF THE STUDY: Rupture of chordae tendineae is the main cause of mitral valve insufficiency, and often requires corrective surgery. The precise mechanisms of chordal rupture, however, are unknown. METHODS: Failure mechanics were measured in porcine mitral valve chordae (37 anterior marginal, 40 anterior basal, 35 posterior marginal, and 38 posterior basal). Full-length chordae were weighed, measured, and stretched to failure in an Instron tensile testing machine. The ruptured ends were characterized under a dissecting microscope. RESULTS: Marginal chordae had 68% thinner cross-sectional areas and failed at 68% less load and 28% less strain than basal chordae. Chordae from the posterior leaflet were 35% thinner and failed at 43% less load and 22% less strain than anterior leaflet chordae. Failure strength was lowest for posterior marginal chordae. Chordae most frequently tore just below the leaflet insertion, in what was often their narrowest section. CONCLUSION: Overall, the marginal chordae and posterior leaflet chordae were thinner and required less strain and load to fail than basal chordae and anterior leaflet chordae, respectively. These results support previous reports of decreased extensibility in marginal chordae. The high incidence of ruptures in the posterior marginal chordae of diseased mitral valves may be due to an inherent weakness in these chordae.     

Five years of experience with mitral valve homografts

INTRODUCTION: The main advantages of mitral homografts are preservation of the subvalvular apparatus and avoidance of life-long anticoagulation. In this communication, we will present our five-year experience using mitral homografts in mitral valve surgery. PATIENTS AND METHODS: Since 1996, 14 patients (mean age 46 +/- 8 years, range 27 - 65 years have had mitral homografts implanted. Thirteen patients had mitral valve replacement; the septal leaflet of the tricuspid valve was replaced in one case. The indications were mitral (n = 6) or tricuspid endocarditis (n = 1), mitral valve stenosis (n = 3), and combined mitral valve disease (n = 4). Complete mitral homografts were implanted in eight patients; partial homografts were used in six cases. Preoperatively, the dimensions of the left ventricle and the mitral valve were measured by transoesophageal echocardiography (TOE). The mean left ventricular ejection fraction was 56 +/- 9%, the mean end-diastolic diameter 58 +/- 6 mm. The technique described by Acar/Carpentier was adapted for implantation; a Carpentier ring was implanted in all cases for annular stabilization. The patients had anticoagulative therapy which was discontinued when stable sinus rhythm was present after three months postoperatively. Follow-up included clinical examination, ECG, and echocardiography, and was initiated six months postoperatively and continued on a yearly basis. The following parameters were determined by echocardiography--left atrial size, left ventricular end-diastolic and end-systolic diameter, pressure gradient across the mitral valve (c/w Doppler, Bernoulli's equation), and mitral regurgitation. RESULTS: All patients survived surgery; the mean operation-time was 281 +/- 37 minutes. Intraoperative TOE revealed a first degree insufficiency in 7 patients. Follow-up was completed in all patients, with a mean period of 30 months (6 - 60 months). Two patients had an acute endocarditis two years postoperatively, requiring repeat valve replacement with a mechanical prosthesis. An additional patient had to be reoperated due to chordal rupture three years postoperatively. All three patients had mitral valve stenosis as the initial indication for surgery and had received a complete homograft. In the remaining eleven patients, the morphological and functional state of the implanted grafts remained unchanged during follow-up. The freedom from valve-related events was 93% after one year, 86% after two years, and 79% after three years. At six-month follow-up, ECG and echocardiography revealed sinus rhythm and sufficient atrial contractions in 13 cases. At the last follow-up, the pressure gradients were 3.4 +/- 0.6 mmHg for complete homografts and 2.8 +/- 0.6 mmHg for partial homografts. In five cases, a mild insufficiency was documented, while six patients presented with competent grafts. CONCLUSIONS: Mitral homografts can be used with acceptable mid-term results in selected cases with good left ventricular function and only slightly dilated left ventricles. Partial mitral homografts represent an additional technique, especially for mitral valve repair in patients with acute endocarditis. The susceptibility to bacterial infections of a homograft makes strict prophylaxis against endocarditis mandatory.     

The role of Chordae tendineae in mitral valve competence

BACKGROUND AND AIM OF THE STUDY: The study aim was to understand the role of different mitral valve chordae tendineae, and how damage to them affects valve competence. METHODS: A test apparatus was used to apply pressure to porcine mitral heart valves that were intact and have had selected chords severed. Anterior leaflet strut and marginal chords were selectively severed, as were posterior leaflet basal and marginal chords. Commissural chords were also severed. RESULTS: Severing anterior leaflet marginal chords (p = 0.018) and commissural chords (p = 0.018) significantly reduced mitral valve competence. Severing posterior leaflet marginal and basal chords, and anterior leaflet strut chords, had no significant effect in reducing the pressures that the valves could withstand. Severing a mixture of posterior leaflet basal and marginal chords significantly reduced the pressure withstood by the valves (p = 0.004). CONCLUSION: The study results confirmed that anterior leaflet marginal chords, but not strut chords, are vital for valve competence. Commissural chords were also shown to be vital for mitral valve competence. Several posterior leaflet chords had to be severed to affect mitral valve competence.