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PubMed1975

[Pre- and postoperative investigations of patients after aortic valve replacement with prosthetic valves or homografts (author's transl)].

Two groups of patients with aortic-valve disease were compared. Group I (18 patients) received prosthetic valves, group II (12 patients) homograft valves. The symptoms and haemodynamic findings improved in both groups, postoperatively. Complications were more frequent with prosthetic than homograft valves, and the haemodynamic responses also were better in the homograft group, especially during exercise.

Adult↗
PubMed1970

Immediate and long-term results of mitral valve replacement with University of Cape Town mitral valve prosthesis.

We describe seven years' experience with the University of Cape Town lenticular mitral valve prosthesis in 122 patients. All the patients had severe mitral valve disease. In 98 severe mitral stenosis was present with or without incompetence and in 24 the dominant or sole lesion was mitral incompetence. Other valves, particularly the tricuspid, were also frequently affected. The disability was severe or total in almost every patient. One hundred and five patients were discharged from hospital, and in 90 per cent of these the clinical improvement was most gratifying, with the disappearance of pulmonary oedema, paroxysmal dyspnoea, angina pectoris, and congestive cardiac failure. Return to full normal activity including physical work was the rule. The hospital mortality was 14 per cent and a further 38 per cent died during the follow-up period. The major post-operative complication was systemic embolism which could occur at any time after operation. The most important factor influencing the frequency of this complication was the nature of the valve seat. A bare steel seat was associated with a 100 per cent embolism, and a significant reduction occurred when a cloth-covered seat of Dacron-velour was introduced. Anticoagulant therapy appeared to prevent large or fresh clots but had no effect on the deposition of fibrin or platelet thrombi. The only other factor of importance was the age of the patient: after the age of 50 life expectancy and trouble-free long-term survival was reduced.

Adolescent↗
PubMed1992

Long-term results of surgery for mitral regurgitation due to mitral valve prolapse: a comparison of valve replacement and annuloplasty.

Patients with mitral regurgitation (MR) due to mitral valve prolapse operated at the Second Department of Surgery, Okayama University Medical School, between 1976 and 1986 were divided into two groups. The first consisted of 20 patients who had mitral valve replacement (MVR) and the second 15 patients who had mitral annuloplasty (MAP). Long-term results of surgery, cardiac function, hemodynamic status, and surgical findings were compared between the two groups. Before surgery, there were no significant differences in patient's clinical status and cardiac function between the two groups. However, after surgery statistically significant differences emerged between the two groups in ejection fraction (EF), cardiac index (CI) and mean circumferential fiber shortening velocity (mVcf). Left ventricular pumping function and myocardial contractile force tended to decrease after surgery in the MVR group and to remain unchanged or even increase in the MAP group indicating that valve preservation procedures should be selected as often as possible for the patients involved in mitral valve prolapse.

Adolescent↗
PubMed2000

Comparative analysis of left ventricular hemodynamics and hypertrophy after aortic valve replacement with homografts or mechanical valves.

BACKGROUND AND AIM OF THE STUDY: The study aim was to examine comparatively the effects of prosthetic and homograft valves in the aortic position on ventricular hemodynamics and structure. METHODS: Hemodynamic evaluations were performed at rest and during exercise in 38 patients who had undergone aortic valve replacement (AVR) with either a homograft (n = 19) or prosthetic valve (19-23 mm; n = 19). Using echocardiographic, electrocardiographic and hematologic methods, the pressure gradient (PG); aortic valve area; diameters of left anterior wall, posterior wall (PW) and interventricular septum (IVS); ejection fraction (EF); left ventricular mass (LVM) and mass index (LVMI); electrocardiographic data of LV hypertrophy; hemoglobin; hematocrit and lactate dehydrogenase (LDH) levels were measured. RESULTS: LVM and LVMI decreased significantly after surgery in both groups (p<0.001), but the decrease was significantly greater in the homograft group (p<0.05). The IVS and PW diameters in the homograft group decreased significantly postoperatively (p<0.05); the inter-group difference was also significant (p<0.01). In the homograft group there was a significant improvement in EF (p<0.05), and the exercise PG was significantly less. Both groups showed improved LV hypertrophy and correlation between V1S >24 mm criteria and LVMI measurements. Postoperative LDH levels in the homograft group were significantly lower than preoperative levels (p<0.05); the intergroup difference was also significant (p<0.001). CONCLUSIONS: Our data suggest that homografts, as compared to mechanical prostheses, provide significantly better hemodynamics in the aortic position.

Adult↗
PubMed2000

Comparison of 21-23 size St. Jude medical valves to the 27-29 size mechanical valves in aortic position. Ten-year follow-up.

BACKGROUND: Between 1986 and 1996, 194 patients underwent isolated aortic valve replacement with 21-23 no. St. Jude Medical mechanical heart valves (small sized group) and 163 patients with 27-29 no. (large sized group). METHODS: The mean age at operation was 45.04+/-15.90 years (range: 12-76 years) for the small sized group and 38.05+/-13.41 years (range: 16-68 years) for the large sized group. Preoperatively, 39.7% of the patients from the small sized group and 42.9% from the large sized group had pure aortic stenosis, 31.9% and 27.6% had pure aortic insufficiency. Most of the patients had rheumatic valve disease. RESULTS: The overall hospital mortality rate was 12.4% and 3.07% respectively in the small sized and large sized groups (p<0.001). The overall actuarial survival rate for 10 years was 95.33+/-2.73% and 93.06+/-3.98% respectively in the small sized group and large sized group (p>0.05). In the small sized group male sex and all complications, in large sized group age and all complications were the statistically important hospital mortality predictors (p<0.05). CONCLUSIONS: Although, operative mortality and long term morbidity were higher in the small sized group, these changes did not reflect the actuarial survivals between the groups. Small sized valves carry some risk, but these risks do not affect long-term survival.

Adolescent↗
PubMed1991

[Marfan's syndrome with annulo-aortic ectasia and ruptured mitral chorda--a case report of combined composite valve graft replacement of the aortic root and mitral valve replacement].

We report a case of Marfan's syndrome with acute heart failure caused by a ruptured mitral chorda that was successfully treated by one operation of combined composite valve graft replacement of aortic root and mitral valve replacement (MVR). A 23-year-old man was admitted to our hospital presenting severe dyspnea and chest pain. Echocardiography and cardiac catheterization studies demonstrated marked annulo-aortic ectasia, aortic regurgitation and significant mitral regurgitation due to a ruptured chorda. In operation, it was found that a chorda of the mitral posterior leaflet had been torn, with the leaflet completely prolapsed to the left atrium, and that the aortic root was dilated to 90 mm in diameter. The ascending aorta was extensively resected leaving those areas of aortic tissue involving the coronary ostia. Then the mobilized coronary arteries were reattached to the composite graft. MVR was performed with preservation of the whole anterior and posterior mitral valve apparatus except for that small part with the torn chorda. Histopathological findings of the aortic wall and mitral valve were compatible with those of Marfan's syndrome.

Adult↗
PubMed1986

[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.

Adolescent↗
PubMed1994

[Aortic valve replacement in a patient with severely calcified small aorta valve and ascending aorta].

A 74-year-old male with severely calcified aortic valve and ascending aorta underwent aortic valve replacement. Cannulation as well as cross clamping of the ascending aorta was avoided because there might be a definite risk of cerebral embolism caused by liberated atheromatous debris on manipulation of the ascending aorta. The extracorporeal circulation was established by femoral arterial and right atrial cannulation, and the aorta was cross-clamped at the soft distal arch. Selective cerebral perfusion catheters were inserted via a longitudinal aortotomy made at a soft anterior portion of the ascending aorta, through which the valve replacement procedure was carried out. The aortic valve annulus was narrow (barely 21 mm in diameter), so that the interrupted mattress suturing technique with the pledgets placed below the annulus in the left ventricular outflow tract was adopted. By this supraannular suturing method a bioprosthesis was easily secured above the annulus as the thickened annulus was compressed between the sutures and the device.

Aged↗
PubMed1998

[A successful valve repair case of isolated tricuspid regurgitation due to traumatic lacerated papillary muscle of the tricuspid valve].

A case of tricuspid valve regurgitation due to a non-penetrating chest trauma was presented. This case involves a 20-year-old man, who was admitted to a nearby hospital because of rib fracture, mandibular fracture, and hemorrhage of the left hemopneumothorax, caused by a traffic accident. Palpitation and chest discomfort were observed at admission time, but there was no follow-up. Tricuspid regurgitation was pointed out during surgery for the mandibular fracture, and he continued follow up treatment at an outpatient clinic. However his palpitation and chest discomfort worsened, and he was admitted to our department 8 month after injury. During surgery to repair the tricuspid valve, a papillary muscle rupture, valve cusp laceration, and anulus dilatation were found. We performed a papillary muscle repair (chorda tendineae reconstruction), valve cusp suture, and annuloplasty. Absence of the left pericardium was observed during the operation. We reported valve repair of traumatic tricuspid regurgitation which with papillary muscle rupture. Due to its rarity and the fact that there has been no reported cases of papillary muscle repair for traumatic tricuspid regurgitation in Japan, we used researched information on the subject.

Adult↗
PubMed1981

Ebstein's anomaly of the tricuspid valve and prolapse of the mitral valve.

The hearts from 10 necropsy patients with Ebstein's anomaly of the tricuspid valve were examined for abnormalities of the mitral valve. Five patients were under 1 year of age and none had an abnormal mitral valve. The other five patients were ages 18 to 72 years (mean 36 years); all had focal fibrous thickening of the mitral leaflets and three had prolapse of one or both mitral leaflets. Only one of the three patients with mitral valve prolapse had an atrial septal defect (secundum type), indicating that the association of mitral valve prolapse with Ebstein's anomaly is not due to the presence of an atrial septal defect.

Adolescent↗
PubMed1993

Velocity-encoded cine MRI in the evaluation of left ventricular diastolic function: measurement of mitral valve and pulmonary vein flow velocities and flow volume across the mitral valve.

Left ventricular diastolic function has been evaluated by means of analysis of the flow pattern through the mitral valve. Velocity-encoded cine magnetic resonance imaging (VEC-MR) is a new method for characterizing flow patterns in the heart. The feasibility of using VEC-MR to measure early diastolic (E) and atrial systolic (A) peak flow velocities and E/A ratios in the mitral inflow, as well as systolic (X), early diastolic (Y), and atrial systolic (Z) peak flow velocities and X/Y ratios in the pulmonary vein, was evaluated in 10 normal volunteers. The VEC-MR-derived velocities and indexes were compared with Doppler-derived results. Volumetric flow across the mitral valve was also used to measure stroke volume, cardiac output, and the left atrial contribution of left ventricular filling. VEC-MR yielded lower peak velocities than Doppler echocardiography. The velocities of the two measurements showed a significant linear correlation (Doppler E velocity = 1.30 x VEC-MR + 1.6 cm/sec, r = 0.68; Doppler A velocity = 1.83 x VEC-MR - 5.2 cm/sec, r = 0.83; and Doppler X velocity = 0.45 x VEC-MR + 0.09 cm/sec, r = 0.74). Consequently the E/A and X/Y ratios measured by these two methods showed statistically significant linear correlations with r values of 0.94 and 0.83. The volume of blood flow across the mitral valve measured by VEC-MR (5610 +/- 620 ml/min) was not statistically different from the cardiac output measured from the ascending aorta by VEC-MR (5670 +/- 590 ml/min) or by left ventricular cine magnetic resonance imaging (5440 +/- 614 ml/min). The left atrial contribution to left ventricular filling was 25.9 +/- 7.5%. Our results indicate that VEC-MR can be used not only for evaluation of left ventricular diastolic filling from the mitral valve and pulmonary vein flow velocities but also for quantitative measurement of the volume of blood flow across the mitral valve.

Adult↗
PubMed1994

Prosthetic valve endocarditis: superiority of surgical valve replacement versus medical therapy only.

The objective of our study was to assess the long-term outcome of patients with prosthetic valve endocarditis. We used a multicenter, prospective, observational study design. Six university teaching hospitals with high volume cardiothoracic surgery participated. Seventy-four patients with prosthetic valve endocarditis as defined by explicit, objective criteria were selected for participation. All patients were followed up prospectively for 1 year. Thirty-one percent and 69% had development of endocarditis within 60 days of valve insertion ("early") and after 60 days ("late"), respectively. The most common causes were Staphylococcus epidermidis (40%), Staphylococcus aureus (20%), streptococcal species (18%), and aerobic gram-negative bacilli (11%). Physical signs of endocarditis (new or changing murmur, stigmata, emboli) were seen in 58%. At 6 months and 12 months, mortality was 46% and 47%, respectively. Surgical replacement of the infected valve led to significantly lower mortality (23%) as compared with medical therapy alone (56%), as assessed by both univariate and multivariate analyses (p < 0.05). Improved outcome was seen for the surgical group even when controlling for severity of illness at time of diagnosis. From these findings we conclude that accurate assessment of outcome in prosthetic valve endocarditis requires long-term follow-up of at least 6 months following diagnosis. Surgical therapy warrants greater scrutiny; evaluation in controlled clinical trials is appropriate.

Adult↗
PubMed1983

Steady flow development past valve prostheses in a model human aorta. II. Tilting disc valves.

The flow development in the model human aorta with uniform entry as well as with centrally occluding valves mounted at the root of the aorta was described in Part I of this two-paper sequence. Part II deals with the flow development in the model aorta with tilting disc valves mounted at the root of the aorta. Bjork-Shiley and Hall-Kaster tilting disc valves were mounted in three different orientations with respect to the root of the aorta. The velocity profiles and turbulent stresses were measured with laser-Doppler anemometry. Our results under steady flow conditions in the model human aorta show quantitatively that the flow development in the ascending aorta as well as in the brachio-cephalic artery are strongly dependent on the orientation of the tilting disc valves. With the valves tilting towards the outer wall of curvature, our results suggest a tendency for flow separation at the flow divider region of the brachio-cephalic artery.

Aorta↗
PubMed2004

Further insights into normal aortic valve function: role of a compliant aortic root on leaflet opening and valve orifice area.

BACKGROUND: This study aims to find the fundamental differences in the mechanism of opening and closing of a normal aortic valve and a valve with a stiff root, using a dynamic finite element model. METHODS: A dynamic, finite element model with time varying pressure was used in this study. Shell elements with linear elastic properties for the leaflet and root were used. Two different cases were analyzed: (1) normal leaflets inside a compliant root, and (2) normal leaflets inside a stiff root. RESULTS: A compliant aortic root contributes substantially to the smooth and symmetrical leaflet opening with minimal gradients. In contrast, the leaflet opening inside a stiff root is delayed, asymmetric, and wrinkled. However, this wrinkling is not associated with increased leaflet stresses. In compliant roots, the effective valve orifice area can substantially increase because of increased root pressure and transvalvular gradients. In stiff roots this effect is strikingly absent. CONCLUSIONS: A compliant aortic root contributes substantially to smooth and symmetrical leaflet opening with minimal gradients. The compliance also contributes much to the ability of the normal aortic valve to increase its effective valve orifice in response to physiologic demands of exercise. This effect is strikingly absent in stiff roots.

Aortic Valve↗
PubMedDate not supplied

Pulmonary valve reconstruction in absent pulmonary valve syndrome: a new technique.

BACKGROUND: In patients with absent pulmonary valve syndrome, the relief of the pulmonary regurgitation at the time of primary repair improves both the early and late results. Though homograft and heterograft valves and conduits have been used for this purpose, both are not easily available and are known for late failure. Monocusp and bicuspid semilunar valves made out of pericardium have their own problems. Hence, a technique of reconstructing an autologous competent 3-cusp valve from the native tissues was developed. METHODS: Two posterolateral semilunar cusps were fashioned from the anterior wall of the main pulmonary artery. The anterior cusp was made from autologous pericardium stitched to the autologous pericardial patch used to widen the right ventricular outflow tract. RESULTS: This method of reconstruction was used in two patients aged 9 and 22 years, respectively. Visual assessment and passive testing after reconstruction revealed well functioning neopulmonary valves in both patients. The second patient, who had an unevenful hospital course, showed only mild pulmonary regurgitation at 5 years postreconstruction. CONCLUSIONS: As 2 of the 3 cusps are fashioned from the pulmonary arterial wall as a pedicled graft, we believe that they will retain their viability and grow with the pulmonary artery. Simultaneous reduction in the size of the pulmonary arteries will relieve bronchial compression when present. The anterior pericardial cusp, even if it eventually shrivels up, is unlikely to produce serious hemodynamic derangements.

Adult↗
PubMed1996

Structural integrity assessment of heart valve prostheses: a damage tolerance analysis of the CarboMedics Prosthetic Heart Valve.

The design of mechanical heart valve prostheses must satisfy three basic requirements: biocompatibility, efficiency and durability. Over the past 25 years of clinical use, pyrolytic carbon has proven to be biocompatible and thromboresistant, and is therefore the material of choice for mechanical heart valve prostheses. However, in recent years the material has been questioned in this application because it is brittle and susceptible to subcritical crack growth. This has raised concerns regarding the structural reliability of prostheses constructed from this material. This paper describes the application of the damage tolerance methodology to assess the structural integrity of heart valve prostheses made of pyrolytic carbon. In particular, an analysis of the CarboMedics Prosthetic Heart Valve (CPHV) is presented. A new measure of fatigue lifetime, the fatigue safe-life index, is introduced. Additionally, the degradation of structural integrity from cavitation erosion is examined. It is shown that structural integrity, especially for brittle materials, is not just a function of design, but involves the entire manufacturing process. The damage tolerance method can be applied to assess and ensure the structural integrity of pyrolytic carbon prosthetic heart valve components.

Biocompatible Materials↗
PubMed2003

Factors determining early improvement in mitral regurgitation after aortic valve replacement for aortic valve stenosis: a transthoracic and transesophageal prospective study.

BACKGROUND: Mitral regurgitation (MR) is frequently associated with aortic stenosis. Previous reports have shown that coexisting mitral insufficiency can potentially regress after aortic valve replacement. HYPOTHESIS: This study sought to assess the frequency and severity of MR before and after aortic valve replacement for aortic stenosis and to define the determinants of its postoperative evolution. METHODS: For this purpose, 30 adult patients referred for aortic valve surgery underwent pre- and postoperative transthoracic and transesophageal echocardiography and color Doppler examination. RESULTS: Mean preoperative left ventricular ejection fraction was 57 +/- 16% and remained unchanged postoperatively. Preoperative MR was usually mild to moderate and correlated with aortic stenosis severity and left ventricular systolic dysfunction. The color Doppler mitral regurgitant jet area significantly decreased during the postoperative period (p = 0.016) as left ventricular loading conditions returned to normal, suggesting an early decrease of the functional part of MR. On the other hand, the mitral regurgitant jet width at the origin remained unchanged. Statistical analysis found pulmonary artery pressure (p = 0.02) an d indexed left ventricular mass (p = 0.009) to be preoperative predictive factors of postoperative MR improvement. Predictive factors of postoperative MR severity were left atrial diameter (p = 0.02), pulmonary artery pressure (p = 0.003), and the presence of mitral calcifications (p = 0.004). CONCLUSION: In our cohort of patients with normal left venticular ejection fraction, the majority of moderate MR, associated with severe aortic stenosis, regresses early after aortic valve replacement. Mitral calcifications and/or left atrial dilation seem to be predictive factors of fixed MR.

Aged↗