Hitoshi Kasegawa

Echocardiographic prediction of left ventricular dysfunction after mitral valve repair for mitral regurgitation as an indicator to decide the optimal timing of repair

OBJECTIVES This study sought to determine whether echocardiography before mitral valve repair (MVR) for mitral regurgitation (MR) was predictive of postoperative left ventricular (LV) dysfunction and useful for deciding the optimal timing of repair. BACKGROUND Some reports have shown that the preoperative echocardiographic data of left ventricular ejection fraction (LVEF) and left ventricular end-systolic diameter (LVDs) were good predictors of postoperative LV dysfunction. However, few reports were based on long-term follow-up data of large numbers of patients who underwent MVR in the last decade. METHODS A total of 274 patients with moderate or severe MR underwent MVR between October 1, 1991, and September 30, 2000. Among them, 171 patients who had both an operation for isolated MR due to degenerative pathology and a postoperative echocardiogram were studied. Postoperative echocardiograms were performed 3.9 +/- 2.4 years after the operation. The LVEF decreased from 66 +/- 10% before surgery to 63 +/- 11% after surgery (p < 0.0001). On univariate analysis, preoperative LVEF and LVDs correlated with postoperative LVEF (r = 0.41 and r = -0.39, respectively). Overall, postoperative LV dysfunction (defined as LVEF <50%) was not frequent (12%). However, the incidence of postoperative LV dysfunction was high in patients with preoperative LVEF <55% (38%) or LVDs > or =40 mm (23%). CONCLUSIONS In patients with MR, the echocardiographic data of LVEF and LVDs were good predictors of postoperative LV dysfunction. When a decrease in LVEF or an increase in LVDs is detected, MVR should be considered to preserve postoperative LV function.

Simple method for determining proper length of artificial chordae in mitral valve repair

A simple method for determining the length of artificial chordae in mitral reconstructive operations is described. A small tourniquet is used for fine adjustment of the length of polytetrafluoroethylene stitches before tying them during leaking test. We have used this technique in 10 consecutive patients with anterior mitral leaflet prolapse since August 1992. Intraoperative transesophageal echocardiography revealed no or only trace mitral regurgitation after valve repair in all cases. This method minimized the time of determining the proper length of artificial chordae and achieved good results.

Right-Sided Partial Sternotomy for Minimally Invasive Valve Operation: “Open Door Method”

A simple technique for minimally invasive valve operations is described. With a 10-cm midline skin incision, excellent exposure of both the mitral and aortic valves is achieved through a right-sided partial sternotomy, which enables us to perform easy repair or replacement of these valves.

Intraoperative TEE during mitral valve repair: does it predict early and late postoperative mitral valve dysfunction?

BACKGROUND Intraoperative transesophageal echocardiography (TEE) using color Doppler flow mapping can accurately measure residual mitral regurgitation (MR), but it is unknown to what extent such measurements correlate with those obtained with postoperative transthoracic echocardiography (TTE). METHODS We used intraoperative TEE (based on direct planimetry of the maximal regurgitant jet area) to measure residual MR in 42 patients who underwent mitral valve reconstruction for MR and compared these measurements with those obtained with early and late postoperative TTE. RESULTS Residual MR as measured by intraoperative TEE correlated significantly with values obtained with both early (r = 0.66; p < 0.0001) and late (r = 0.71; p < 0.0001) postoperative TTE. Forty patients with no or trivial MR (< or =2 cm2) as measured by intraoperative TEE also had no or trivial MR as measured by early (probability of 87.5%) and late (probability of 80.0%) postoperative TEE. Of the 40 patients, 6 had clinically insignificant mild MR (< or =4 cm2) when measured by late postoperative TTE. Two other patients in whom intraoperative TEE showed mild MR developed moderate regurgitation about 3 months later. CONCLUSIONS Intraoperative TEE correlates with early and late postoperative TTE in measurement of residual MR, suggesting it can reliably predict early and late postoperative mitral valve dysfunction.

Mechanisms of Recurrent Regurgitation After Valve Repair for Prolapsed Mitral Valve Disease

BACKGROUND We assessed mitral valve (MV) function using serial echocardiography as an indicator of the durability of MV repair. The aim of this study was to analyze the mechanisms of recurrent regurgitation after MV repair for degenerative disease. METHODS From 1991 to 2007, 736 patients had valve repair for mitral regurgitation caused by leaflet prolapse: 346 patients had posterior and 390 had anterior leaflet prolapse. The mean age was 54.6±14.6 years, with 495 males. The durability and mechanisms of recurrent regurgitation were evaluated by the findings of echocardiography and reoperation. Follow-up and late echocardiography averaged 5.7±3.9 and 5.1±3.6 years, respectively. RESULTS Survival was 91.9%±1.5% at 10 years. Freedom from reoperation and moderate or severe regurgitation at 10 years were 91.2%±1.7% and 84.5%±2.1%, respectively. Reoperations were performed for recurrent regurgitation in 29 patients, hemolysis in 5, and endocarditis in 1. Based on the findings of reoperation, the mechanisms of repair failure were procedure related in 9 (25.7%), valve related in 25 (71.4%), and unknown in 1. Late echocardiography revealed none to trivial regurgitation in 511 patients, mild in 153, moderate in 26, and severe in 40. Anterior leaflet prolapse, preoperative atrial fibrillation, and no use of annuloplasty ring were independent predictors of recurrent regurgitation. The main causes of moderate or severe regurgitation were leaflet thickening in 34 patients, leaflet prolapse in 20, dehiscence in 10, and unknown in 2. CONCLUSIONS The main mechanism of recurrent regurgitation after MV repair is progressive degeneration that is characterized by leaflet thickening and prolapse, especially in patients with anterior leaflet prolapse.

Long-Term Outcome of Mitral Valve Repair for Infective Endocarditis

BACKGROUND In patients with mitral endocarditis, reconstruction of the damaged mitral valve (MV) is still challenging, and its durability remains unknown. We evaluated the long-term outcomes of MV repair for mitral regurgitation (MR) in patients with infective endocarditis. METHODS From 1991 to 2006, 633 patients had MV repair for MR caused by leaflet prolapse: 78 had endocarditis (active in 14, healed in 64) and 555 had degenerative disease. Durability was assessed by reoperation and recurrent MR. RESULTS The overall hospital mortality rate was 1.0% (endocarditis 0% vs degenerative 1.1%; p = 0.99). The 10-year survival and freedom from reoperation were 91.1 +/- 1.6% and 92.2 +/- 1.7%, respectively, with no differences between endocarditis and degenerative disease. Older age, New York Heart Association class III or IV, impaired ventricular function, and no use of annuloplasty were independent predictors of all-cause death. Freedom from moderate or severe MR was 99.8 +/- 0.2% at 2 weeks, 91.9 +/- 1.5% at 5 years, and 83.3 +/- 2.3% at 10 years, for all patients and did not differ between groups at 10 years (p = 0.388). Anterior leaflet prolapse, preoperative atrial fibrillation, and no annuloplasty were independent predictors of recurrent MR. In endocarditis patients, recurrent MR was mainly caused by leaflet thickening and calcification, but not by recurrence of endocarditis. CONCLUSIONS MV repair for endocarditis is associated with low operative mortality and morbidity, and its long-term durability is comparable with that of repair for degenerative disease. This study suggests that a degenerative process causes late failure after MV repair for endocarditis.

Long-term outcomes of artificial chordal replacement with tourniquet technique in mitral valve repair: a single-center experience of 700 cases.

OBJECTIVE Artificial chordal replacement has been shown to be effective and durable, with numerous techniques reported. However, the outcomes of each technique have remained poorly defined. We report the long-term outcomes of the tourniquet technique. METHODS We reviewed the data from 700 patients who had undergone mitral valve repair with the tourniquet technique from 1992 to 2010. We analyzed the operative outcomes, long-term survival rate, freedom from reoperation, and freedom from recurrent moderate or severe mitral regurgitation (MR). We also performed Cox regression analysis to explore the predictors of recurrent MR after mitral valve repair using the tourniquet technique. RESULTS The mean age was 54.7±14.9 years; 212 patients (30.3%) had anterior leaflet prolapse, 142 (20.3%) had posterior leaflet prolapse, and 346 (49.4%) had bileaflet prolapse. Operative mortality was 1.3%. In 26 cases (3.7%), mitral valve repair was unsuccessful and was converted to replacement. Of those successfully repaired, the 12-year survival rate, freedom from mitral reoperation, freedom from recurrent moderate or severe MR, and freedom from recurrent leaflet prolapse was 85.9%, 88.7%, 72.3%, and 89.0%, respectively. The significant predictors of recurrent MR were anterior leaflet prolapse, age, New York Heart Association class III or IV, left ventricular end-systolic dimension, no annuloplasty ring or band, and postoperative residual mild or greater MR. CONCLUSIONS The tourniquet technique is a simple and effective method to repair leaflet prolapse, with a low incidence of recurrent prolapse. The incidence of recurrent MR was high in the anterior leaflet prolapse group. Age, no annuloplasty ring or band, and residual MR were strong predictors of recurrent MR.

Mitral valve repair by Carpentier-Edwards Physio annuloplasty ring

A semi-flexible annuloplasty ring (Physio-ring) was clinically used in 30 cases of mitral valve insufficiency. The Physio-ring has the characteristics in which the anterior section is rigid and has a saddle-shaped curve, while the posterior section is flexible to allow for changes in size and shape of the anulus during ventricular contraction. The patients were aged from 23 to 73 years (mean 53.8 +/- 12.5). The cause of mitral valve insufficiency was degenerative (in 24 patients), rheumatic (2), ischemic (1), endocarditis (1), congenital + degenerative (1), and traumatic (1). On the 6-month post-implant echocardiogram, 96.6% had grade 0 or +1 regurgitation. The effective valve orifice area was 2.61 +/- 0.82 cm2 (n = 19). There was no late death. However, there was 1 (3.3%) hospital death after the patient had received a simultaneous coronary artery bypass grafting, and then developed low output syndrome after surgery. Although there was no device-related complication, hemolysis of undetermined cause was observed in 1 (3.3%) patient. The findings from this study indicated a low incidence of device-related complication, while excellent valvular function was maintained.

The successful surgical repair of a left ventricular-right atrial communication and aneurysm of the mitral valve caused by infective endocarditis : report of a case

We report herein the case of a 42-year-old man who developed a left ventricular-right atrial communication and aneurysm of the mitral valve caused by infective endocarditis, which was associated with aortic regurgitation. Based on the findings of congestive heart failure, prolongation of the PR interval, and the added threat of rupture of the mitral aneurysm, surgical treatment was decided upon as the best course of action. The aortic and mitral valves were replaced with prosthetic mechanical valves, and the septal communication was simultaneously closed with a patch. The patients postoperative course was uneventful and he has been in good health since. Thus, we believe that aggressive surgical intervention for complicated lesions such as those seen in our patient may be life-saving, even in the presence of inflammatory signs.

Influence of left ventricular function on development of systolic anterior motion after mitral valve repair

OBJECTIVE A hyperkinetic heart has been suggested as a risk factor for systolic anterior motion (SAM) after mitral valve repair, but the influence of preoperative left ventricular (LV) function on the development of SAM has not been elucidated. METHODS Transthoracic echocardiographic data were retrospectively reviewed in 441 patients who underwent mitral valve repair for degenerative mitral regurgitation. Comparisons were made between patients with and without SAM (SAM cases vs noncases). RESULTS The incidence of SAM was 6.1% (27/441). There were no differences in preoperative characteristics and operative procedures between the 2 groups except the prevalence of Barlow disease. The SAM cases exhibited a higher preoperative ejection fraction (EF) (SAM cases, 70.0% ± 7.1%; noncases, 65.1% ± 6.9%; P < .01) and smaller preoperative systolic LV end-systolic dimension (LVDs) (32.0 ± 5.4 mm vs 35.4 ± 5.7 mm; P = .02) than the noncases. The incidence of SAM was significantly associated with greater preoperative EF (P < .01 for trend) and reduced LVDs (P < .01 for trend). SAM did not occur in patients with an impaired (EF < 60%) or enlarged (LVDs > 45 mm) LV. The incidence of SAM was highest among patients with a small hyperkinetic heart. CONCLUSIONS The study indicates that the development of SAM after mitral valve repair is associated with preoperative LV function. A small hyperkinetic heart is considered a risk factor for SAM and should be treated with caution.