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Biomedical subjects

P Venugopal

Publications and source records attributed to P Venugopal.

At least 145 records · Page 8Linked to original sources
PubMed1984

Thrombotic obstruction of Bjork-Shiley valves--diagnostic and surgical considerations.

We have evaluated 12 patients with thrombotic obstruction of the Bjork-Shiley valve since 1975, 11 in the mitral and 1 in the aortic position. During this period 442 patients with 303 mitral (181 plano-convex and 122 convexo-concave) and 205 aortic (112 plano-convex and 93 convexo-concave) Bjork-Shiley valves were available for follow-up. The incidence of thrombosis for the plano-convex model was 1.06% per patient year for the mitral position and 0.19% per patient year for the aortic position. The new convexo-concave model has brought down the incidence to 0.78% per patient year for the mitral (P less than 0.01) and 0% per patient year for the aortic valve. The onset of symptoms was acute (less than 15 days) in 41.7% and subacute (greater than 15 days) in 58.3% patients. All patients presented with pulmonary edema. Evidence of inadequate anticoagulation was present in only 3 (25%) patients. Reduction of prosthetic sounds and appearance of a new murmur was highly suggestive of valve thrombosis. Echocardiography and cinefluoroscopy was very useful for the instant recognition of this condition and had obviated the need for cardiac catheterisation in the last 6 patients. Emergency surgery was obligatory in all. Thrombectomy alone was successful in 9 patients. Three patients required replacement of the prosthesis. There was one operative death (mortality 8.3%). The long-term follow-up of these patients (3-82 months, mean 34 months) is excellent. We conclude that thrombotic obstruction of the Bjork-Shiley valve is often not related to inadequate anticoagulation, and more than half of the patients do not present with abrupt onset of symptoms. The convexo-concave model has significantly reduced this problem. Emergency surgery with thrombectomy is the procedure of choice for clotted prostheses.

Adult↗
PubMed1984

Valve replacement in children under twenty years of age. Experience with the Björk-Shiley prosthesis.

Prosthetic valve replacement in young patients has been reported to be associated with a high mortality and morbidity because of valve-related problems. Of 549 patients undergoing valve replacement with the Björk-Shiley valve prosthesis, 136 were under the age of 20 years. Sixty-four patients were under 16 years of age, the youngest being 6 years old. Of the 136 patients, 61 underwent mitral valve replacement, 50 received an aortic valve, and 25 received both aortic and mitral valves. Overall operative mortality was 10.3%. Late mortality over a follow-up period of 6 months to 8 years was 4.4%. Actuarial survival curves up to 8 years of follow-up are presented. Results obtained in this group are compared with those obtained in 413 patients over 20 years of age operated during the same period. Valve thrombosis was not seen in any patient under 20 years of age, but it occurred in 4.13% of the patients over 20 years of age. The incidence of thromboembolism and anticoagulant-related hemorrhage was very low. There has been no instance of structural failure of the valve. Long-term results are excellent, with 90% of the survivors returning to New York Heart Association Functional Class I. The Björk-Shiley valve gives excellent and durable long-term palliation in young patients requiring valve replacement.

Actuarial Analysis↗
PubMed1983

Thrombosis of Björk-Shiley valve prostheses. Evaluation by cineradiography.

Cineradiography is the most accurate and rapid method in evaluation of the function of Björk-Shiley prosthetic valves manufactured after late 1975 and which incorporate a tantalum foil hoop into the disc. This helps in demonstration of the disc and in the calculation of the opening angle of the disc. In the present series 8 cases with valve dysfunction have been correctly diagnosed by conventional cineradiography, 7 in the mitral and one in the aortic position. In all 8 cases and also in the group of 300 postoperative cases having no symptoms, the opening angle has been measured by the method described by Venkataraman et coll. in 1980. It is recommended that in accordance with the suggestions of these authors, the opening angle should be established for each patient in the immediate postoperative period in order to provide a basis for possible future examinations.

Adult↗
PubMed1982

Cell block study.

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Cytodiagnosis↗
PubMed1975

Anomalous origin of the left coronary artery from the pulmonary artery. Definitive surgical treatment by saphenous vein interposition in a 17-month-old child.

A 17-month-old child underwent successful operative correction of anomalous origin of the left coronary artery from the pulmonary artery by saphenous vein interposition. The clinical, hemodynamic, and angiographic features of the anomaly are presented. Three months after the operation, cardiac catheterization and angiography revealed a patent graft with good antegrade flow and improvement in left ventricular function.

Age Factors↗
PubMedDate not supplied

Pediatric oncology in India.

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Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Measurement of apoptosis, proliferation and three cytokines in 46 patients with myelodysplastic syndromes.

Extensive apoptosis or programmed cell death (PCD) of both hematopoietic (erythroid, myeloid, megakaryocytic) and stromal cells in myelodysplastic syndromes (MDS) cancels the high birth-rate resulting in ineffective hematopoiesis and has been demonstrated as the probable basis for peripheral cytopenias in MDS by our group. It is proposed that factors present in the microenvironment are inducing apoptosis in all the cells whether stromal or parenchymal. To investigate this hypothesis further, bone marrow biopsies from 46 MDS patients and eight normal individuals were examined for the presence of three cytokines, tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta) and granulocyte macrophage-colony stimulating factor (GM-CSF) and one cellular component, macrophages, by the use of monoclonal antibodies immunohistochemically. Results showed the presence of TNF-alpha and TGF-beta in 41/46 and 40/46 cases of MDS respectively, while only 15 cases showed the presence of GM-CSF. Further a significant direct relationship was found between the degree of TNF-alpha and the incidence of PCD (p= 0.0015). Patients who showed high PCD also had an elevated TNF-alpha level. Thus, the expression of high amounts of TNF-alpha and TGF-beta and low amounts of the viability factor GM-CSF may be responsible for the high incidence of PCD leading to ineffective hematopoiesis in MDS. Future studies will be directed at attempting to reverse the lesion in MDS by using anti-TNF-alpha drugs such as pentoxifylline.

Apoptosis↗
PubMedDate not supplied

Sinus of Valsalva aneurysms: 20 years' experience.

BACKGROUND: Aneurysms of sinus of Valsalva are rare. Here, we analyze retrospectively patients operated on at our center during the last 20 years. PATIENTS AND METHODS: One hundred four cases of congential aneurysm of sinus of Valsalva were operated upon between January 1977 and April 1996. Only 12 aneurysms were unruptured. The majority (76.9%) arose from the right coronary sinus. The right ventricle was the most common chamber of rupture (58.6%). Ventricular septal defect was associated in 46 patients (44.2%), of which 28 (60.9%) were supracristal. Ventricular septal defect was more common in aneurysms arising from the right coronary sinus (91.3%). Aortic incompetence was found in 45 patients (43.3%). The defect was closed through the aortic root alone in 24 patients (23.1%) and through both the aortic root and the chamber of rupture in the remaining 80 patients. Six patients underwent aortic valve repair, and 21 an aortic valve replacement. RESULTS: There were two hospital deaths (1.92%). Morbidities were few. Follow-up ranged from 1 to 20 years (mean 8.2 +/- 1.1). There was one late noncardiac death, and in the majority, the long-term follow-up was uneventful. CONCLUSION: Surgery for aneurysm of sinus of Valsalva yields gratifying results, and it should be undertaken as soon as the condition is diagnosed.

Adolescent↗
PubMedDate not supplied

Transesophageal echocardiography during surgical closed mitral commissurotomy.

We report a case of a 28-year-old woman with severe mitral stenosis for which surgical closed commissurotomy was done. Intraoperative transesophageal echocardiography was performed to assess its utility during this surgical procedure. It was helpful in instant confirmation of the adequacy of the surgery, detecting residual mitral regurgitation, and in visualisation of the Tubbs dilator that is used to accomplish mitral commissurotomy.

Adult↗