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PubMed2001

The trans-septal approach to the mitral valve.

To assess the efficacy of the trans-septal approach to the mitral valve, 40 patients who underwent mitral valve surgery via this approach were compared to 37 patients who underwent surgery via the standard left atriotomy. Concomitant procedures included tricuspid annuloplasty, aortic valve replacement, closure of atrial septal defect, coronary artery bypass grafting and aortic valve repair. There was one (1.2%) operative mortality. No patients required pacemaker implantation. Follow-up of up to 18 months showed that all patients were in NYHA classes I and II. One third of the patients who had trans-septal approach to the mitral valve achieved conversion from atrial fibrillation to sinus rhythm while none of the patients who underwent conventional left atriotomy had conversion (p < 0.02). The trans-septal approach to the mitral valve is a useful approach in selective patients requiring mitral valve surgery.

Adolescent↗
PubMed1992

Bovine mitral valve organ culture: role of interstitial cells in repair of valvular injury.

The atrial and ventricular surfaces of the mitral valve are lined by endothelial cells termed endocardial cells, while the valve stroma contains interstitial cells. Bovine mitral valve organ cultures were immunoperoxidase-stained for Factor VIII RAg, alpha smooth muscle actin, and PCNA/cyclin in order to identify the cell types involved in mitral valve wound repair. Factor VIII RAg is a well-characterized endothelial cell marker, alpha smooth muscle actin is an indicator of smooth muscle differentiation and PCNA/cyclin is a marker for S phase. Bovine mitral valve endocardium was Factor VIII RAg positive and remained positive after culturing for 6 days (n = 7). Mitral valve interstitial cells were Factor VIII RAg negative and positive for alpha smooth muscle actin. By 6 days in culture, the lateral edges of the preparations, where the tissue was originally dissected from the mitral valve leaflet, were covered by multiple layers of cells. These cells were Factor VIII RAg negative (n = 7), and hence not endocardial, but were alpha smooth muscle actin positive like interstitial cells. Interstitial cells subjacent to the lateral edges were negative for PCNA/cyclin in uncultured preparations (n = 5), but positive in 12 out of 15 specimens cultured for 6 days. The results suggest that mitral valve interstitial cells are responsible for the repair process seen in the lateral edges of mitral valve organ cultures.

Animals↗
PubMed1992

Anatomically complete heterograft mitral valve substitute: surgical technique and immediate results.

The use of a totally anatomical mitral valve heterograft as a mitral valve substitute has been proven to be technically feasible. A new stentless mitral porcine heart valve substitute was therefore developed to match the physiology and flow characteristics of the left ventricle and mitral valve complex, and tested in non-survival animal experiments. Having sought the approval of the Hospital Ethics Committee and the consent of each individual patient, this valve was implanted into 18 patients with diseased mitral valves. The duration of the procedure is approximately the same as for standard mitral valve replacement. The sizing of the valve and the anchoring of the sutures to the papillary muscle, although very straightforward, do require adherence to a protocol. The immediate clinical results are encouraging, although the first patient required a reoperation because of a patient/valve mismatch. All patients, including the patient reoperated, are in functional class I after four to 26 weeks of follow up. The patients will be followed by monthly clinical and Doppler echocardiographic examinations, as they have been so far, for the next 12 months, and annually thereafter.

Adolescent↗
PubMed2004

Three-dimensional echocardiography for planning of mitral valve surgery: current applicability?

BACKGROUND: Two-dimensional transesophageal echocardiographic (2D TEE) assessment of the mitral valve requires mental integration of a limited number of 2D imaging planes. Structural display in three dimensions from any perspective may be of advantage to the surgeon for better judgment and planning. METHODS: Feasibility, accuracy, and limitations of preoperative three-dimensional transesophageal echocardiography (3D TEE) was assessed in 51 patients with mitral valve disease. The width of the anterior mitral valve was measured with either method and compared with the operative finding. Three-dimensional dynamic sequences of the reconstructed mitral valve were shown preoperatively to the surgeon and later compared with the intraoperative finding. RESULTS: The quality of the 3D reconstruction was graded as good in 25 patients (49.0%), fair in 16 patients (31.4%), and poor in 10 patients (19.6%) where atrial fibrillation did not allow ECG gating. Thirty-nine patients had successful mitral valve repair and twelve patients required valve replacement. Based on intraoperative findings, sensitivity for the diagnosis of mitral valve prolapse using 2D TEE and 3D TEE was 97.7% and 92.9% (p = ns) respectively and specificity was 100% by both methods. Sensitivity for the diagnosis of rupture of chordae tendineae using 2D TEE and 3D TEE was 92.3% and 30.8% respectively (p < 0.05) and specificity was 100% by both methods. CONCLUSIONS: Dynamic 3D echocardiography is feasible and can provide good insight into valvular motion and allows adequate preoperative planning when reconstruction is being considered. However dynamic 3D reconstruction is currently limited by the quality of the original 2D echo cross sectional images which can be adversely affected by minimal patient movements, breathing, or cardiac arrhythmia, thus limiting accuracy of the 3D TEE significantly compared with 2D TEE.

Aged↗
PubMed1999

Immediate effects of mitral valve replacement on left ventricular function and its determinants.

Patients undergoing mitral valve surgery are at risk of left ventricular failure in the immediate post-operative period. In order to understand better the mechanisms of post-operative haemodynamic instability, we used transoesophageal echocardiography to assess the immediate response of the left ventricle to mitral valve replacement for mitral regurgitation or stenosis. A decrease in left ventricular preload, despite adequate filling pressures, was common to both groups and suggests the presence of diastolic dysfunction. A marked impairment in global systolic pump function was observed only in the regurgitation group and correlated with the left ventricular afterload. Transoesophageal echocardiography provides valuable information on the individual changes in left ventricular function and its determinants after mitral valve replacement that are not reflected by haemodynamic measurements.

Anesthesia, General↗
PubMed1977

Preoperative evaluation of the structural lesion of the mitral valve by M-mode scan echocardiography.

M-mode scan echocardiographic studies of the mitral valve were performed in order to investigate structural architecture of the diseased mitral valve. Structural lesion of the mitral valve was assessed by the echo-pattern change, an increase in number or thickness of the diastolic mitral echo complex. The echo-pattern was classified into 4 grades according to number or thickness of the mitral echoes. The echo-pattern grade correlated with the degree of the structural lesion of 21 surgically excised mitral valves. Clinically, the echo-pattern grade was compared with subsequent operative procedure in 56 cases with pure or predominant mitral stenosis (42 open commissurotomy, 14 valve replacement). Grade I or grade II echo-pattern was a good indicator for mitral commissurotomy. Grade IV pattern was a reliable criterion for valve replacement. Mitral valve replacement should be also considered in cases with grade III pattern, 38% of whom underwent valve replacement. C-E amplitude of the mitral valve was not a useful parameter in assessing the surgical procedure. Thus, the echo-pattern obtained by M-mode scan technique appeared to be of valve in planning the surgical approach for patients with pure or predominant mitral stenosis.

Adult↗
PubMed2006

Influence of the opening mode of the mitral valve orifice on intraventricular hemodynamics.

We analyzed intraventricular blood flow numerically to study the influence of the mode of mitral valve opening on the flow field in the left ventricle. Four different types of opening mode were examined: gradually axisymmetric, gradually anteroposterior (anatomical), gradually bilateral (anti-anatomical), or instantaneous opening and closing. In these models, the shape of the valve orifice was the same when the mitral valve was opened fully. The results demonstrated that the framework of the velocity profile of transmitral flow was built during the phase of mitral valve opening, which was characterized by the mode of valve opening. After the mitral valve opened completely, the transmitral velocity profile developed while maintaining its topological features. Consequently, each mode of mitral valve opening had its own pattern of intraventricular flow, although mitral valve opening accounted for less than 4% of a cardiac cycle. Particle tracking in the resulting flow field revealed that ventricular ejection was more efficient in the anteroposterior and axisymmetric opening modes. These results addressed the importance of the mode of mitral valve opening in intraventricular flow dynamics.

Blood Flow Velocity↗
PubMed1989

[Angiographic diagnosis of lesions of the mitral valve and its appendages].

68 cases with 76 left ventriculographies, including rheumatic mitral valvular disease, congestive and hypertrophic types of cardiomyopathy, endocardial cushion defect, atrial and ventricular septal defects, coronary heart disease and mitral valve prolapse were analyzed with respect to the morphological and functional changes of the mitral valve and its appendages. Dynamic study with cineradiographic technic was the chief method used in this investigation. Except for ventricular septal defect, all the above-mentioned disease entities showed one or several of the changes of the mitral valvular apparatus including stenosis, insufficiency, displacement, cleft, deformity, prolapse and functional disorder. Regurgitation associated with mitral insufficiency exhibiting specific manifestations in different conditions was analyzed and its method of grading discussed. Mitral valve prolapse with its suggested method grading and functional disorder of the mitral valve were also discussed in detail.

Cardiomegaly↗
PubMed1983

Floppy mitral valve and ventricular septal defect: an anatomic study.

Eighteen percent of heart specimens with isolated ventricular septal defect also had a floppy mitral valve. There was no statistical difference in the incidence of floppy mitral valve in the three age groups considered (less than 1 year, 1 to 16 years and 17 to 91 years). In no patient was a floppy mitral valve considered to be the cause of death. Complications of floppy mitral valve (ruptured chordae tendineae, bacterial endocarditis, mitral regurgitation and fibrin deposits at the mitral valve-left atrial angle) occurred at approximately the same frequency as that reported in autopsy studies of isolated floppy mitral valve. In the specimens with floppy mitral valve and ventricular septal defect, 63% also had floppiness of the tricuspid valve, 16% of the pulmonary valve and 5% of the aortic valve. The anatomic basis for floppy mitral valve was considered to be spongiosal invasion and disruption of the fibrosa of the valve leaflet. In this study, spongiosal invasion of the fibrosa was fully developed by 3 months of age and there was no evidence that the incidence or severity of spongiosal invasion increased between the ages of 3 months and 88 years. These data suggest that the floppy mitral valve is a congenital lesion that reaches full anatomic expression in infancy. No evidence was found that ventricular septal defect and floppy mitral valve share a common etiology.

Adolescent↗
PubMed2004

Tissue Doppler imaging and echo-Doppler findings associated with a mitral valve stenosis with an immobile posterior valve leaflet in a bull terrier.

A mitral valve stenosis was diagnosed in a 2-year-old female Bull Terrier by use of two-dimensional (2-D) and M-mode echocardiography, colour-flow imaging and spectral Doppler examinations. Tissue Doppler Imaging was also performed to assess the segmental radial myocardial motion. The mitral valve stenosis was characterized by a decreased mitral orifice area/left ventricle area ratio (0.14), an increased early diastolic flow velocity (E wave = 1.9 m/s), a prolonged pressure half-time (106 ms) and a decreased E-F slope (4.5 cm/s) on pulsed-wave Doppler examination. This mitral stenosis was associated with an immobile posterior leaflet, as seen on 2-D and M-mode echocardiography. Immobility of the posterior mitral leaflet is considered to be a rare finding in humans and, to our knowledge, has not been precisely documented in dogs with mitral valve stenosis.

Animals↗
PubMed2004

Minimally invasive mitral valve repair using the da Vinci robotic system.

BACKGROUND: Minimally invasive mitral valve repair with a shortened hospital stay and quick return to an active lifestyle is the ultimate goal for robotically assisted surgery. We evaluated our da Vinci robotically assisted mitral valve repair experience toward achieving this goal. METHODS: All procedures were performed with peripheral cardiopulmonary bypass, transthoracic aortic cross-clamp, and antegrade cardioplegia. Two ports and a 4-cm intercostal incision in the right chest were used for access. All patients had a ring annuloplasty, and all but 1 had a posterior leaflet resection. The entire repair and all knot tying were performed robotically. RESULTS: Between October 2001 and October 2002, 25 patients (18 men) underwent robotic mitral valve repair. The mean age was 56 years (range, 37 to 81 years). There were no incisional conversions, deaths, strokes, or reoperations for bleeding. Twenty-one (84%) of 25 patients were extubated in the operating room. Overall mean study times were as follows: procedure, 199.7 minutes (range, 140 to 287 minutes); cardiopulmonary bypass, 126.6 minutes (range, 89 to 186 minutes); and cross-clamp, 87.7 minutes (range, 58 to 143 minutes). Eight (32%) patients were discharged home in less than 24 hours, with an average length of stay of 2.7 days. Comparing the first 10 patients to the last 15 there was a significant reduction of times: total operating room time, 318.5 versus 275.1 minutes; cross-clamp, 97.6 versus 81.1 minutes; leaflet resection or repair, 26.2 versus 15.6 minutes; annuloplasty ring, 31.9 versus 24.8 minutes; and length of stay, from 4.2 days to 1.67 days. Five patients had postoperative atrial fibrillation. Two (8%) patients ultimately required mitral valve replacement for recurrent mitral insufficiency. CONCLUSIONS: Mitral valve repair can be successfully performed with the da Vinci robotic system. Long-term follow-up is needed to determine the durability of the repair compared with a standard sternotomy approach.

Adult↗
PubMed1980

Echocardiographic demonstration of porcine mitral valve vegetation and dehiscence.

The echocardiographic study of a patient with a malfunctioning porcine valve in the mitral position is presented. Echocardiography of the mitral valve revealed multiple, dense heterogeneous echoes behind and within the valve stent which were suggestive of vegetations. At the aortic valve level, a clear systolic echo in the left atrium was recorded. This echo probably represented the prolapsing anterior valve stent and was caused by a major dehiscence of the valve stent due to endocarditis.

Adult↗
PubMed1998

The "annular sandwich": a simple method of reinforcing a friable mitral valve annulus.

In 6 patients undergoing prosthetic mitral valve replacement a ring of Teflon felt, instead of conventional Teflon pledgets, was used because of concern about seating a new prosthesis in a disrupted friable mitral valve annulus. The technique avoided the potential risk of pledget loss in the event of suture breakage and, in these patients, prevented postoperative paraprosthetic mitral valve regurgitation.

Echocardiography, Transesophageal↗
PubMed2000

[Fundamentals and indications for mitral valve repair surgery].

The concept of mitral valve repair is discussed, emphasizing the basic knowledge on which it relies, and the breakthrough it has produced in modern cardiac surgery. This concept challenges the myth of the artificial prosthesis, showing the superiority of autologous biological structures submitted to plastic repair. The foundations of valvular repair and the techniques that have contributed to its success are reviewed, and the advantages for the patients in terms of quality of life, and preservation of the left ventricular function are discussed.

Bioprosthesis↗
PubMed1990

In vivo identification of mitral valve fibrosis and calcium by real-time quantitative ultrasonic analysis.

Conventional echocardiography provides fundamental information about mitral valve morphology and function but has a relatively low specificity in evaluating valve calcific deposits, which is critical information for the preoperative decision to perform commisurotomy or replacement. In vitro radiofrequency ultrasonic quantitative analysis of the mitral valve has been demonstrated to be a reliable tool in identifying normal, fibrotic and calcific valves. This study evaluates quantitative ultrasound characterization of the mitral valve in vivo. Thirty-three patients, scheduled to undergo mitral valve replacement, and 20 normal subjects (10 young and 10 older control subjects) were studied with a 2.25-MHz transducer. Radiofrequency signal was analyzed by a microprocessor system (used with an M-mode commercially available echocardiograph) for on-line evaluation of ultrasonic backscatter with 8 bits of amplitude resolution, 40-MHz sampling rate and a 1-microsecond acquisition gate. The integrated value of the rectified radiofrequency signal amplitude was deemed the integrated backscatter index. The highest value recorded with the ultrasonic analysis from each valve was taken as representative and expressed as the percent value with respect to the pericardial integrated backscatter index value of that subject. The 33 excised mitral valves underwent histologic examination. Four groups were identified: young controls (group I, n = 10); older controls age-matched with patients (group II, n = 10); patients with fibrotic mitral valves (group III, n = 13); and patients with calcific mitral valves (group IV, n = 20).(ABSTRACT TRUNCATED AT 250 WORDS)

Calcinosis↗
PubMed1998

Approach for primary mitral valve surgery: right anterolateral thoracotomy or median sternotomy.

BACKGROUND AND AIMS OF THE STUDY: Although both right anterolateral thoracotomy and median sternotomy have been used for mitral valve surgery (repair/replacement), the latter approach is considered standard for primary mitral valve surgery. We hypothesized that primary mitral valve surgery, if performed through a right anterolateral thoracotomy, would not only be better accepted cosmetically by patients, but also make redo surgery through a median sternotomy easy and trouble free from re-entry bleeding. METHODS: A right anterolateral thoracotomy was used for primary mitral valve surgeries in 52 patients (group A; 22 males, 30 females) of mean age 30.3 +/- 09.14 years (range: 14 to 50 years). Equal numbers of cases operated on during the same period by via median sternotomy were selected retrospectively from hospital records to serve as controls (group B). Groups were matched with respect to age, body weight, body surface area, sex, cardiac rhythm, functional status, type of mitral valve pathology and associated lesions. RESULTS: Operative mortality was similar in both groups, but fewer postoperative complications occurred in group A. Total hospital stay, intensive care unit stay, postoperative bleeding, inotrope requirement and ventilatory support postoperatively was significantly less in group A. CONCLUSIONS: Right anterolateral thoracotomy provides excellent exposure of the mitral valve, even with a small left atrium, and offers a better cosmetic lateral scar which is less prone to keloid formation. In addition, right anterolateral thoracotomy is as safe as median sternotomy for primary mitral valve repair/replacement, and should be used as an initial approach to mitral valve surgery, while median sternotomy be kept for repeat mitral valve or other open-heart surgery required later in life.

Adult↗
PubMed1995

Systemic lupus erythematosus valvulitis: mitral valve replacement with a homograft.

For many years, valvulitis in systemic lupus erythematosus has been known to occur. Our patient was a 17-year-old girl who presented with severe mitral incompetence and renal insufficiency due to lupus valvulitis. The patient was first treated by mitral valve repair, but follow-up disclosed precocious calcification of the valve, necessitating mitral valve replacement with a cryopreserved homograft. At follow-up after 1 year, echocardiography has shown the valve to be functioning normally. A reconstructive mitral valve operation would seem to be preferable. However, a conservative operation does not alter the natural history of the disease and the progression of valve thickening and calcification.

Adolescent↗