Search PubMed⌕ Search

Biomedical subjects

N Trehan

Publications and source records attributed to N Trehan.

At least 19 recordsLinked to original sources
PubMed2006

Prevalence of cardiovascular risk factors in Indian patients undergoing coronary artery bypass surgery.

BACKGROUND: Conventional cardiovascular risk factors (CVRFs) are known to influence short-term and long-term outcome following coronary artery bypass graft surgery (CABG). There has been recent increase in prevalence of CVRFs in general population in India. However no information is available regarding the prevalence of same in patients undergoing CABG. METHODS AND RESULTS: In this cross-sectional study, one thousand consecutive patients undergoing elective CABG were included and data on major CVRFs was obtained in them. Mean age of the patients was 59.73 +/- 9.5 years and 884/1000 (88.4%) patients were males. 505/994 (50.8%) patients had BMI > or = 25.0 kg/m2 and 747/994 (75.2%) had BMI > or = 23.0 kg/m2. Diabetes mellitus was present in 475/1000 (47.5%) patients (46.5% men and 55.2% women), hypertension in 709/1000 (70.9% overall; 70.8% men and 71.6% women) and dyslipidemia in 781/913 patients (85.6% overall; 84.5% men and 93.9% women). 213/913 (23.3%) patients had LDL > or = 100mg/dl, 662/913 (72.5%) patients had low HDL and 338/913 (37.0%) patients had elevated triglycerides. 199/1000 (19.9%) patients (18.7% men and 29.3% women) had family history of premature CAD and 545/1000 (54.5%) patients (53.4% men and 62.9% women) had at least one family member having CAD (irrespective of the age of onset). 94/1000 (9.4%) patients (10.4% men and 1.7% women) were current smokers and another 302/1000 (30.2% overall; 33.7% men and 3.4% women) had history of smoking in the preceding one year. 876/913 (95.9%) of all the patients had at least one of the five major CVRFs and only 37/ 913 (4.1%) patients (4.1% men and 4.3% women) were free of all these risk factors. Sixty-one of the 1000 patients (6.1%) were younger than 45.0 years of age. As compared to older patients, dyslipidemia, family history of premature CAD and smoking were commoner in patients less than 45 years of age. In contrast, diabetes and hypertension were more prevalent in the older individuals. CONCLUSIONS: The present study showed high prevalence of most of the conventional CVRFs, esp. diabetes, hypertension and dyslipidemia in Indian population undergoing CABG.

Adult↗
PubMed2001

Further reduction in stroke after off-pump coronary artery bypass grafting: a 10-year experience.

BACKGROUND: Perioperative stroke is a devastating complication after coronary artery bypass grafting (CABG). The reported incidence of neurologic complications after conventional CABG is 3% to 7%. With improved monitoring and surgical techniques, we have been able to achieve a drastic reduction in the stroke rate in our institution. This study evaluates the incidence of neurologic sequelae in patients who underwent off-pump CABG. METHODS: Over a 10-year period from January 1990 to September 2000, off-pump coronary artery bypass (OPCAB) operation was performed on 2,800 patients of the 18,037 patients undergoing CABG during that time frame at the Escorts Heart Institute and Research Centre. Initially, OPCAB was performed selectively in the high-risk group of patients (atheromatous aorta, renal impairment, chronic obstructive pulmonary disease, octogenarians, etc). Lately we performed multivessel OPCABs electively in about 60% to 65% of the patients undergoing CABG. Results. Mean age of the patients was 58.0 +/- 9.91 years (range 27 to 85 years) and mean number of grafts was 2.9 per patient. Neurologic complications (stroke/transient ischemic attack) occurred in 0.14% of patients. Overall hospital mortality in OPCAB patients was 2.14%, whereas mortality from neurologic complications was 0.07%. Predicted mortality (National Society of Thoracic Surgeons Cardiac Surgery Database Risk Model for CABG) for the entire patient group was 3.86% (p < 0.001). Conclusions. Although current techniques of monitoring and surgical procedures have significantly reduced the risk of stroke from CABG, our data strongly support OPCAB as a technique to further reduce stroke after CABG, especially in the high-risk group of patients.

Adult↗
PubMed2001

Functional status of the hand after radial artery harvesting: results in 3,977 cases.

BACKGROUND: The radial artery is being used as a conduit of choice over saphenous vein with increasing frequency. We analyzed early and midterm results of coronary artery bypass grafting using radial artery as one of the conduits. The functional outcome of the hand after radial artery harvesting was analyzed. METHODS: The radial artery was used in 3,977 patients undergoing coronary artery bypass grafting between December 1996 and November 2000. Modified Allen's test was performed preoperatively in the ward and pulse oxymetry was used in the operating theater to assess the collateral circulation of the hand. A total of 4,172 anastomoses were performed using a radial artery. The patients were followed up at regular intervals in the outpatient clinic or were sent questionnaires. The functional results of the hand were assessed. Follow-up angiography was performed in 104 patients at a mean of 18 months. RESULTS: The hospital mortality was 0.8%. Perioperative myocardial infarction occurred in 1.3% of patients. The average number of grafts was 3.12. No patient had acute ischemic injury of the hand. Follow-up was complete in 94% of patients. Late infection developed in 0.4% of patients. Numbness and paresthesias continued in 6.5% and 3% patients, respectively, after 3 months. The patency rate of the radial and left internal mammary artery was 92.3% and 96.0%, respectively, at a mean of 18 months. CONCLUSIONS: Use of radial artery for coronary artery bypass grafting is associated with low morbidity and good functional outcome of the hand. It can be used more frequently as the conduit of choice after the internal mammary artery.

Adult↗
PubMed2001

Comparison of continuous thoracic epidural and paravertebral blocks for postoperative analgesia after minimally invasive direct coronary artery bypass surgery.

OBJECTIVE: To compare continuous thoracic epidural analgesia (TEA) and paravertebral block (PVB) for postoperative analgesia in patients undergoing minimally invasive direct coronary artery bypass (MIDCAB) surgery for quality of analgesia, complications, compliance to chest physiotherapy, hemodynamics, and respiratory effects. DESIGN: Prospective, randomized study. SETTING: Specialty research hospital. PARTICIPANTS: Forty-one consenting patients undergoing MIDCAB surgery. INTERVENTIONS: Patients in the TEA group had an epidural catheter inserted at the T4-5 interspace, whereas patients in the PVB group had a catheter inserted in the paravertebral space on the left side at the T4-5 level. MEASUREMENTS AND MAIN RESULTS: Parameters evaluated included visual analog scale pain scores at rest and while coughing, supplemental analgesic requirement, complications, hemodynamics, and respiratory parameters. Measurements were made at 2-hour intervals for 12 hours beginning at 10 minutes after endotracheal extubation. There was no statistically significant difference in visual analog scale scores and requirement of supplemental analgesia between the 2 groups. Cardiac index at 4 hours and 6 hours was significantly higher in the TEA group. Patients in the PVB group had significantly lower respiratory rates at 8, 10, and 12 hours. All other parameters were comparable. In 1 patient, the epidural space could not be catheterized. One patient in the TEA group had transient hypotension, and 1 patient complained of backache at the site of the epidural catheter insertion. CONCLUSION: PVB is as effective as TEA for postoperative analgesia after MIDCAB surgery. PVB is technically easier than TEA and may be safer than TEA because no complications were seen in the PVB group.

Analgesia, Epidural↗
PubMed2001

Discrete subvalvular aortic stenosis in adults.

Discrete subvalvular aortic stenosis is a relatively rare condition in adults. It is often diagnosed during first decade of life especially in association with other congenital malformations. Isolated form of discrete subvalvular aortic stenosis may however silently progress from innocent murmurs of childhood and adolescence to symptomatic left ventricular outflow tract obstruction in adults. Certain overt and subtle morphological abnormalities may underlie the initial expression as well as high recurrence rates after surgical resection of sub aortic membrane. Though surgical resection is the only treatment available, debate on the surgical technique and appropriate timing of surgery continues. Close followup with serial echocardiographic examinations in patients detected to have functional murmurs during childhood may be helpful in early detection of subvalvular aortic stertosis.

Adult↗
PubMed2000

Surgical strategies in patients at high risk for stroke undergoing coronary artery bypass grafting.

BACKGROUND: Perioperative stroke represents one of the major complications following coronary artery bypass grafting (CABG). The present study was designed to evaluate the use of an individualized surgical approach for reducing neurological injury in patients undergoing CABG at high risk of stroke from aortic atherosclerosis or carotid disease. METHODS: Between January 1993 and June 1999, 6,138 patients undergoing elective CABG were evaluated by intraoperative transesophageal echocardiography. Patients were screened preoperatively for internal carotid artery disease. Based on the intraoperative transesophageal echocardiography findings the surgical technique was individualized: hypothermic circulatory arrest with aortic atherectomy, CABG combined with transmyocardial laser revascularization on the beating heart, off-pump CABG by midsternotomy, ministernotomy, minimally invasive direct CABG, hybrid procedure, and so on. Patients were divided into four groups: a low-risk group (no significant aortic or carotid disease); an aortic atheromatous disease group (A.ATH); a carotid disease group (CD); and a carotid disease combined with aortic atheromatous disease group (CD + A.ATH). RESULTS: The incidence of stroke in the low-risk group (n = 5,043) was 0.92% compared with 0.96% in the A.ATH group (n = 918). In the CD group (n = 166) the incidence of stroke was 0.6% whereas it was 0% in the CD + A.ATH group (n = 11). CONCLUSIONS: Preoperative and intraoperative screening can detect extensive atherosclerosis of the proximal aorta and internal carotid artery. Selective use of surgical techniques in this group of high-risk patients can prevent adverse neurologic sequelae while achieving complete myocardial revascularization.

Aged↗
PubMed2000

Off-pump redo coronary artery bypass grafting.

BACKGROUND: Conventional redo coronary artery bypass grafting is associated with significant morbidity. The danger of reoperation is mainly in reopening the sternum and in the manipulation of the heart and the old grafts. Therefore, off-pump redo coronary artery bypass grafting with a patient-specific approach in selected cases seems an ideal technique. METHODS: Between October 1995 to September 1999, 50 patients with mean age of 61.8+/-8 years underwent reoperative coronary artery bypass grafting without cardiopulmonary bypass. Isolated left internal mammary artery (LIMA) to left anterior descending artery (LAD) anastomosis was carried out in 25 cases through left anterior minithoracotomy. In 1 patient LIMA was grafted on a previous vein graft to LAD, which was critically stenosed proximally but distal anastomosis was patent. In another case LIMA was grafted to Ramus intermedius branch. Midsternotomy approach was used to carry out LAD and right coronary artery grafting in 21 cases. In 2 patients a posterolateral thoracotomy approach was used to bypass obtuse marginal branches without cardiopulmonary bypass; in these cases proximal anastomosis was performed on the descending aorta. RESULTS: Mortality rate was 4% (2 deaths). Two patients sustained perioperative myocardial infarction. No patient was reexplored for hemorrhage and 38 patients did not require homologous blood transfusion. Sixteen patients underwent check angiogram and all of them were found to have patent redo grafts. Cardiac recovery room stay was 22+/-7 hours and hospital stay 5+/-2 days. CONCLUSIONS: In selected patients, reoperative coronary artery bypass grafting can be performed without cardiopulmonary bypass with a low perioperative morbidity and mortality and satisfactory graft patency.

Coronary Artery Bypass↗
PubMed2000

Reduced neurological injury during CABG in patients with mobile aortic atheromas: a five-year follow-up study.

BACKGROUND: Mobile atheromas of the thoracic aorta have been identified as a major cause of stroke after coronary artery bypass grafting (CABG). This prospective study was undertaken to identify mobile atheromas and to determine the incidence of immediate postoperative embolic events after suitable surgical modifications. Late clinical events attributable to embolization were also studied. METHODS: Between January 1993 and July 1997, 3,660 patients scheduled for CABG underwent intraoperative transesophageal echocardiography to identify aortic atheromatous disease. The disease was graded as follows: grade I, plaques extending less than 5 mm into the aortic lumen; grade II, plaques extending more than 5 mm into the aortic lumen; and grade III, plaques with a mobile element. Only patients with grade III atheromas were included in the study. Various surgical modifications were done depending on the location of the lesion, eg, aortic arch atherectomy, CABG combined with transmyocardial laser revascularization, off-pump CABG by median sternotomy, and minimally invasive direct coronary artery bypass. Measured outcomes were death, stroke, and other vascular events, both early (within 1 week) and late (1 to 5 years) after operation. RESULTS: Of the 3,660 patients, 104 (2.84%) had mobile atheromas. The perioperative stroke rate was 0.96%, and the incidence of other vascular events was 1.92% at 1 week. There was no embolic event in the group of 88 patients who underwent off-pump CABG. Of the study group, 98.07% are in regular follow-up. At 5 years, 1 patient had had a nonfatal stroke, and 2 patients had died of causes unrelated to atheromatous disease. CONCLUSIONS: The stroke rate was very low in patients with mobile aortic atheromas who underwent CABG after modification in surgical technique, especially off-pump CABG. A follow-up of 5 years showed that patients with mobile atheromas have a very low incidence of spontaneous embolization.

Adult↗
PubMed2000

Comparison of ministernotomy with minithoracotomy regarding postoperative pain and internal mammary artery characteristics.

PURPOSE: This prospective clinical study focuses on postoperative pain and internal mammary artery (IMA) characteristics after ministernotomy versus left anterior minithoracotomy. METHOD: Patients were studied in two groups. Group A consisted of 267 consecutive single vessel (IMA to left anterior descending artery (LAD)) minimally invasive direct coronary artery bypass (MIDCAB) patients using ministernotomy from the tip of the xiphoid to the fourth intercostal space. Group B consisted of the same number of MIDCAB patients operated on through anterolateral minithoracotomy. Pain was graduated using the visual analog scale (VAS). Internal mammary artery (IMA) characteristics were compared in both the groups. RESULTS: Postoperative pain was not significant statistically on postop day (POD) 1 in either of the groups (p = 0.07). From POD 2 onwards Group A patients had less pain than Group B patients (p < 0.05), and the pain medication requirement from POD 2 onwards was less in Group A than in Group B. Length of harvested IMA was 15.6 +/- 2.1 cm in Group A as compared to 10.4 +/- 2.2 cm in Group B (p < 0.05). Free flow of IMA in group A was 56 +/- 16 ml/min., whereas in Group B the flow was 50 +/- 14 ml/min. (p = 0.04). CONCLUSION: Compared to patients undergoing MIDCAB using ministernotomy, anterolateral minithoracotomy patients suffer more pain from POD 2 onwards and their postoperative pain medication requirement is also higher. Length and free flow of IMA is better in patients operated on for MIDCAB using ministernotomy. Thus, ministernotomy is a better approach than minithoracotomy in terms of postoperative pain and IMA characteristics for single-vessel MIDCAB patients.

Adult↗
PubMed2000

Discrete subvalvular aortic stenosis.

Discrete Subaortic Stenosis is one of the many lesions responsible for left ventricular outflow tract (LVOT) obstruction. It may present as in an isolated from as membranous or fibromuscular ring below the aortic valve or in association with other congenital anamolies such as VSD, PDA, coarctation of aorta, hypoplastic aortic annulus, double chamber right ventricle among others. The condition is rarely diagnosed antenataly or in infancy but often manifests in the first decade of life with features of progressive LVOT obstruction, LV hypertrophy and dysfunction aortic regurgitation due to damage to the aortic cusps because of the jet from the subaortic narrowing which may also render the aortic valve prone to infective endocarditis. Interaction of genetic predisposition and morphologically deformed long and narrow LVOT cause rheological abnormalities and increased shear stress in the region of subaortic stenosis and seem to be the main etiological factor alongwith poorly defined role of more extensive but subtle changes in the LV endocardium. Condition can be easily diagnosed by cross-sectional and Doppler echocardiography and confirmed by demonstrating a pressure gradient below aortic valve on cardiac catheterisation and LV angiography. Surgical membranectomy alongwith myotomy or myomectomy remain the mainstay of treatment but long term results are not satisfactory as there is a high rate of recurrences requiring reoperations. A close follow up with serial echocardiographic examinations is very helpful in early detection of subaortic obstruction in patients who have so called functional murmurs in the childhood.

Angiography↗
PubMed1999

Minimally invasive mitral valve surgery through right anterolateral minithoracotomy.

BACKGROUND: This study evaluates the feasibility of minimally invasive mitral valve surgery. The aim of the study was to minimize surgical access to achieve better cosmetic results, less postoperative discomfort, and faster recovery. METHODS: From September 1997 to October 1998, 76 patients underwent mitral valve surgery through a right anterolateral minithoracotomy at the fourth intercostal space. The mitral valve was either repaired (n = 21) or replaced (n = 55). In all cases, open femoral artery-femoral vein cannulation was used for cardiopulmonary bypass. In 27 cases, an endoluminal aortic clamp was used, but in 49 cases, the aorta was cross-clamped with a transthoracic, sliding-rod-design clamp. RESULTS: There were no approach-related limitations to surgical intervention. Intraoperative transesophageal echocardiography revealed excellent results after valve repair and no paravalvular leak in any patient after mitral valve replacement. Mean duration of intensive care and postoperative hospital stay was 32+/-5.2 hours and 7+/-1.1 days, respectively. There were no major complications related to femoral vessel cannulation. In 1 patient, transient neurological problems developed, with subsequent complete recovery. There was one hospital mortality (85-year-old male patient died of upper GI bleeding). CONCLUSIONS: Minimally invasive port access mitral valve surgery can accelerate recovery and decrease pain, while maintaining overall surgical efficacy. It also provides better cosmetic results to our patients, and now it has become our standard approach for isolated mitral valve surgery.

Adult↗