B.V. Sai Chandran

Effect of CYP2C9 and VKORC1 genetic polymorphisms on mean daily maintenance dose of acenocoumarol in South Indian patients

AIM To determine the effect of CYP2C9 and VKORC1 genetic polymorphisms on mean daily maintenance dose of acenocoumarol in South Indian patients with heart valve replacement. MATERIALS AND METHODS The study was conducted in 170 patients on therapy with acenocoumarol following heart valve replacement surgery. Single nucleotide polymorphisms (SNP) namely CYP2C9*2 (rs1799853), CYP2C9*3 (rs1057910), and VKORC1 (rs9923231) were identified by quantitative Real-Time Polymerase Chain Reaction (RT-PCR) method. RESULTS Patients with at least one variant allele of CYP2C9 (*1*2 or *1*3) required 44% and 28.2% lower daily maintenance dose of acenocoumarol (2.0mg and 2.5mg, respectively) than the normal CYP2C9*1*1 genotype group (3.4mg) (p<0.05). Patients with VKORC1 GG genotype required higher dose (3.3mg) as compared to those with genotype VKORC1 GA (2.3mg) and VKORC1 AA (1.0mg) (p<0.001). Patients with both CYP2C9*1*2/*1*3 and VKORC1 GA genotype required 38% lower dose (2.46mg) than patients with CYP2C9*1*1 and VKORC1 GG genotype (3.52mg) (p<0.0001). The clinical (age, body mass index) and genetic variables (VKORC1-1639 G>A, CYP2C9*2, CYP2C9*3) contribute together to predict 30.4% of the required maintenance dose of acenocoumarol. CONCLUSION The genetic polymorphisms of CYP2C9 and VKORC1 results in decreased requirement of daily maintenance dose of acenocoumarol. The polymorphism VKORC1 (-1639 G>A) was found to be the major predictor of acenocoumarol dose requirement in South Indian population.

Double-lumen tube for ventilation in severe kyphoscoliosis

The presence of kyphoscoliosis can adversely affect gas exchange because of restriction to gas flow and reduction of lung volume. The effects become more exaggerated during positive-pressure ventilation due to the uneven distribution of ventilation. The use of a double-lumen tube helps to reduce the ventilation perfusion mismatch that occurs because of positive-pressure ventilation. We report a patient with severe kyphoscoliosis who underwent repair of an atrial septal defect, in whom a double-lumen tube was used for ventilation and the conduct of general anesthesia.

Phosphatase and tensin analog expression in arterial atherosclerotic lesions

CONTEXT Phosphatase and tensin analog (PTEN) gene mutation has been proven for pro-inflammatory property and proliferative potential through tyrosine kinase pathway. We studied mutated PTEN for its pathogenetic association in arterial atherosclerosis. AIMS The objective was to study mutation of PTEN by immunohistochemical method in arterial atherosclerotic lesions and correlate with grades of atherosclerosis, smooth muscle migration in intima, degree of inflammation and Framingham heart study risk factors. SETTINGS AND DESIGN Human, Prospective Clinical study. MATERIALS AND METHODS We studied patients with arterial occlusive disease diagnosed by Doppler ultrasonography over a 2-year period. Immunohistochemistry was performed with mouse monoclonal antibodies for PTEN and smooth muscle actin (SMA). STATISTICAL ANALYSIS USED Chi-square test. RESULTS AND CONCLUSION Aorta was the single most common vessel affected (21%). Mean age of patients studied was 48.6 years and 80% were male. Mutant PTEN was associated with higher grades of atherosclerotic lesions (P < 0.0001) graded by American Heart Association classification and with smooth muscle proliferation and migration in intima (P < 0.0001). No statistically significant association with the vessel wall inflammation and other risk factors of atherosclerosis.

Combined nephrectomy and aortic valve replacement: perioperative decision-making

Open heart surgery and urologic surgery may be required for patients with coincident diseases. We report a patient who suffered from aortic valve stenosis which was asymptomatic barring atrial fibrillation. He was prescribed warfarin and then developed a large perinephric hematoma. The perioperative considerations focused on whether to conduct aortic valve replacement for this patient and, if such surgery was indicated, the appropriate time to conduct it. Traditionally, severe cardiac disease is addressed first before conducting elective noncardiac surgery; however, this option was not available since the patient already had a perinephric hematoma which could bleed more when subjected to systemic heparinization for cardiopulmonary bypass. Here, we describe the process of perioperative decision-making involving multiple specialities and re-examine several guidelines.

Are Congenital Arteriovenous Malformations of Proximal Upper Extremity, More on the Right: Case Report and Literature Review

This is a case of a 9-year-old boy with a congenital arteriovenous malformation (AVM) of the right upper extremity arising from the right subclavian artery. He underwent open surgical excision of the vascular tumor. Upon reviewing the literature, a high incidence of right-sided congenital AVM of the proximal upper extremity was identified. It has been suggested that this high incidence may be related to the complexity of the embryologic development of the right subclavian artery.

Multiple Serial Aneurysms of Brachial Artery With Multiple Arteriovenous Malformations of Forearm

Brachial arterial aneurysm is a rare entity. We present a case of multiple serial aneurysms of the brachial artery with associated multiple arteriovenous malformations of the forearm, along with symptoms of distal ischemia and its surgical management.