Allograft valves for aortic and mitral valve replacement

OBJECTIVE: To evaluate nuclear grading on fine needle cytopunctures of breast carcinoma, which is of special interest when neoadjuvant chemotherapy is planned. STUDY DESIGN: In a prospective study, we compared cytologic grading, based on nuclear parameters (pleomorphism and mitosis), to modified Scarff-Bloom-Richardson histologic grading in 105 primary operable breast carcinomas. The results of these two nuclear grading systems were compared to Feulgen image analysis data from the corresponding cytologic samples. RESULTS: The concordance rate between the two grading systems was 76%. Concordance between cytologic and histologic grading was observed more frequently in purely invasive carcinomas (85%) than in cases combining invasive and in situ components (56%). A highly significant relationship was observed between the two grading systems and indices of proliferative activity (S-phase fraction, proliferation index, 5c exceeding rate and endoreduplication rate), particularly in concordant grading. Furthermore, nuclear area correlated with the results of the two grading systems. CONCLUSION: Cytologic nuclear grading appeared to be a reliable tool for a large proportion of breast tumors. Despite difficulties related to tumor heterogeneity, which could be detected by careful cytologic examination, it is a useful alternative to histologic grading.     

Choosing a prosthetic heart valve

Although most of the available prosthetic heart valves function remarkably well, the variety of available choices attests to the inability of any single one to fulfill the requirements of the ideal valve substitute. The mechanical prostheses include the caged-ball, tilting-disc, and bileaflet valves. Tissue valves available in the United States are the Carpentier-Edwards and Hancock porcine heterograft valves and the Carpentier-Edwards pericardial valve. Review of several large comparative studies on valve performance reveals that the overall results with tissue and mechanical valves are about equal at the end of 10 years. The characteristics of each type of valve substitute dictate the selection of one prosthesis in preference to others for a particular patient. Mechanical prostheses are recommended for patients without contraindications for anticoagulants. Tissue valves are reserved for patients over 65 years of age or for patients in whom anticoagulation is contraindicated. Multiple other patient-related factors need to be considered in selecting the appropriate valve, including the psychosocial situation and patient preference.     

Blood rheology in patients with native heart valve disease and after valve replacement

Patients with heart valve disease have rheologic abnormalities that are more pronounced in double valve disease than in mitral or aortic valve disease; after valve replacement surgery, the degree of rheologic abnormality is more pronounced in patients with mechanical and biological prostheses than in those with homografts and pulmonary autografts. Rheologic abnormalities seen in these patients might be related to the different incidences of thromboembolism in the presence of various valve defects and various types of prostheses.     

Exercise tests before and after heart valve replacement

A simple progressive exercise test was performed before and after operation on five subjects undergoing mitral valve replacement and on five subjects undergoing aortic valve replacement. The responses of heart rate and ventilation were related to work rate )kilopond metres/min). The patients were also assessed clinically by the New York Heart Association grading and radiologically before each exercise test. The clinical grading was shown to be a poor guide to observed exercise tolerance, as the improvement noted in symptoms was not matched by the objective measurement of working capacity. Only two patients had normal exercise tolerance after surgery, although six of the ten patients claimed that they had no exertional dyspnoea after operation. The changes in simple ventilatory function tests before and after operation were generally small. We suggest that measurements of exercise tolerance before and after operation should be an essential part of heart valve replacement surgery.     

Thirty years experience with heart valve surgery: isolated mitral valve replacement

BACKGROUND: Thirty years have elapsed since the commencement of open-heart surgery in South Australia. A retrospective study was performed to evaluate mortality and complication rates and to identify factors associated with poor outcomes in all patients who underwent prosthetic mitral valve replacement during this period. METHODS: Questionnaires and personal contact have been used to generate a combined database of pre-operative and post-operative information and long-term follow-up on 938 patients who underwent isolated prosthetic mitral valve replacement at the Cardio-Thoracic Surgical Unit of the Royal Adelaide Hospital between 1963 and 1993. RESULTS: Complete survival follow-up data were obtained for 92% (865) of the patients. The Starr-Edwards valve was used in 95% (891) of the patients, a Bjork-Shiley prosthesis in 2.5% (23) of the patients, and only 24 (2.5%) other valves were inserted. The hospital mortality rate for the 30-year period was 4.7%. The mean age of the patients who underwent surgery was greater in each of the three successive decades. A long-term survival advantage was observed for patients with mitral stenosis, however, survival was significantly shorter for patients with higher New York Heart Association (NYHA) functional classifications and for patients in pre-operative atrial fibrillation. Pre-operative dyspnoea was significantly improved following mitral valve replacement. The rates of postoperative haemorrhagic and embolic complications were low by comparison with other published series. CONCLUSION: Mitral valve recipients do not regain a normalized life expectancy, but risk factors that determine long-term survival can be identified pre-operatively to aid appropriate patient selection.     

Chronicle of a defective heart valve prosthesis

The Bj?rk-Shiley convexo-concave (BScc) strut fracture problem is about to enter its third decade. At present, valve carriers still face the risk of outlet strut fracture; a risk which does not seem to decline. The temporising attitude of the manufacturer has led to far more victims than would have been necessary but also the Food and Drug Administration, regulatory agencies outside the US and the medical community share responsibility for this problem.     

The link between drug use and heart valve disease

We report MRI and angiographic findings of an unusual giant arachnoid granulation in the left sigmoid sinus in a boy with headache. Its signal intensity was lower than that of cerebral cortex on T1-weighted images and higher on T2 weighting, mimicking dural sinus thrombosis.     

Lambl's excrescence as tumorous heart valve mass

HISTORY AND CLINICAL FINDINGS: A 44 year old woman consulted a general physician because of weakness and fatigue. 5 months ago otitis media and a urinary tract infection had been treated successfully with antibiotics. The physical examination was unremarkable except for healed scars after an orthopedic operation about 35 years ago and a resection of a benign tumor of the left breast about 14 years ago. INVESTIGATIONS: Except for a slightly elevated antistreptolysin titer the laboratory tests were normal. The ECG showed sinus rhythm, left axis deviation and normal ST-segments. In the transthoracic echocardiogram an echogenic mass adherent on the ventricular side of the noncoronary cusp of the aortic valve in size of 2 x 1.5 cm could be demonstrated. The mass moved with the normally functioning valve and prolapsed into the aorta ascendens. The Doppler-echocardiogram was normal. TREATMENT AND COURSE: Because of the size of this echogenic mass with unknown origin and the risk of an embolic event its removal was indicated. This was done without destroying the aortic valve. Postoperative echocardiography demonstrated normal valve function. The histologic examination showed an endothelialized mass, rich in fibers and with only a few fibroblasts and histiocytes, without smooth muscle cells, according to a Lambl's excrescence. CONCLUSION: Cardiac valve tumors are rare. The differentiation between surface excrescences on the cardiac valve and neoplasia is only possible by histologic examination. Because of its possible malignancy and the potential risk of emboli surgical treatment is indicated.     

Tricuspid valve replacement after orthotopic heart transplantation

Atrioventricular valvular regurgitation is a known complication after cardiac transplantation. In this communication, we describe a case of progressively severe tricuspid insufficiency that ultimately necessitated tricuspid valve replacement. The patient has done well clinically since valve replacement, and a postoperative cardiac catheterization demonstrated normal right heart hemodynamics. A discussion of proposed causes and a review of the literature are provided.     

Ventricular pressure slope and bileaflet mechanical heart valve closure

The maximum left ventricular pressure slope (dP/dt) value has been used by several investigators as the criterion for studying mitral valve closure. In this article, the relationship between the ventricular pressure slope (dP/dt) and the leaflet closing behavior of bileaflet mechanical heart valves (BMV) is investigated. Two current BMVs, the St. Jude Medical 29 mm and CarboMedics 29 mm, installed in the mitral position of a mock circulatory pulsatile flow loop were used as the study model. Under simulated physiologic pressures and flow conditions, the experiment was conducted at 70, 90, and 120 beats/min with corresponding flow rates of 5.0, 6.0, and 7.5 liters/min, respectively. A laser sweeping technique was used to monitor the leaflet closing motion within the last 3 degrees excursion at valve closure. A modified dual beam laser sweeping technique system was used to register the difference of leaflet/housing impact time between the two BMV closing leaflets in asynchronous closure. Common BMV asynchronous closures were found in both BMVs at all three heart rates tested. The second closing leaflet was found to always close at higher velocity than the first. Simultaneous measurements of the ventricular pressure (Pv) and the leaflet closing time showed that Pv exhibited three stage characteristics. In the first stage, Pv gradually increased as the ventricle was filled. A sudden rise of Pv occurred immediately after closing of the first leaflet. The maximum dp/dt occurred in the third stage after closure of both BMV leaflets. The BMV closing behavior and the corresponding Pv pattern were found to depend strongly upon valve type and heart rate. The time averaged ventricular pressure slope (dp/dt) values at 70, 90, and 120 beats/min were about 40, 70, and 150 mmHg/sec for the St. Jude Medical valve and 40, 105, and 205 for the CarboMedics valve during the first closing stage. The maximum dp/dt values were 2670, 4350, and 5000 mmHg/sec for the St. Jude Medical valve and 1210, 2530, and 3210 mmHg/sec for the CarboMedics valve at the three heart rates tested, respectively. The study showed that the left ventricular pressure patterns (dP/dt) at valve closure were the result of valve operation under given driving conditions. The dp/dtmax cannot be used as the criterion for studying BMV closure.     

M-mode and two-dimensional echocardiography of heart valve prosthesis dysfunction

The diagnostic efficacy of M-Mode and 2-d echocardiography for the detection of malfunctioning prosthetic valves was studied in twenty-nine patients with prosthetic valves and clinical deterioration. Echocaradiographic abnormalities were found in 8 of 12 patients with confirmed valve dysfunction; 30.8% of the cases had false negative echo tracings. In 17 patients with normal echocardiographic pictures of the valves another cause of clinical deterioration was found (congestive heart failure, pericardial effusion, aneurysm of aortic root). In this study M-Mode and 2-d echocardiography had an excellent diagnostic accuracy rate in distinguishing congestive heart failure from valve dysfunction. Comparing the data of M-Mode and 2-d registration, both methods are found to be complementary. A major advantage of the 2-d echocardiography is its enhanced spatial orientation, whereas M-Mode echocardiography enables better evaluation of valve movements and corresponding time intervals and recognition of quick movements and fibrillations.     

Decontamination tests of heart valve grafts with cialit

Only a small proportion of patients with carcinoma of the stomach are suitable for radical surgery. For the remainder symptomatic treatment and radiotherapy alone or in combination with chemotherapy can be used to relieve distressing symptoms of pain, nausea and vomiting, and severe anemia. In the case of radiotherapy or chemotherapy, a degree of tumor regression can be expected. There have been encouraging results recently in palliating this disease with new radiotherapy techniques, notably fast neutron irradiation.     

The cost of treating heart valve related complications

This paper presents 5 patients with repeated recurrence of osteosarcoma (RROS). The primary focus of 3 patients were in the distal portion of femur, and 2 patients were in the proximal portion of tibia. Three patients, whose chest X ray film were negative, were treated by amputation and chemotherapy. Two patients had isolated metastatic focus 1.5 cm in diameter in lung, were treated by amputation after 1 week of chemotherapy and then treated by lobectomy after 2 weeks of chemotherapy. After operation, the chemotherapy was carried out for 3 courses of treatment. The roentgenogram of chest and affected limb were taken once every two months. There were metastatic focuses found in the lung of 1 patient and in the distal portion of femur of 2 patients. One patient was operated on for 4 times. Up to now, 3 patients have been living for 5 years and 2 patients for 6 years after operation.