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Biomedical subjects

S Aranki

Publications and source records attributed to S Aranki.

9 recordsLinked to original sources
PubMed2001

Transmyocardial laser revascularization.

Low-powered lasers were first used in the early 1980s to produce transventricular channels as an adjunct to coronary artery bypass graft surgery (CABG). Early results were encouraging, but because of the combined procedure, could not be attributed directly to use of the laser [1]. High-powered lasers were introduced into clinical practice in 1990 [2]. These lasers are powerful enough to create a transmyocardial channel with minimal thermal damage to surrounding tissues [3]. Clinical studies, using transmyocardial laser revascularization (TMR) as the sole operative therapy for patients with severe and diffuse coronary artery disease (CAD) who have Class III or IV angina, and are on medical therapy, have been conducted since 1993. Based on the results of these studies, the FDA granted approval for the use of TMR as a sole therapy. Clinical studies are currently underway to assess the results of combined TMR and CABG [4]. Results of four controlled randomized studies have been published [5-8]. The data from two of these studies formed the basis for FDA approval of two different types of laser systems. The results of these studies have not provided any additional insights into the mechanism of action of TMR, which remains the Achilles' heel of this procedure. In this review, background information about the TMR procedure will be discussed along with an analysis of the recently published randomized studies.

Angina Pectoris↗
PubMed1999

QEEG changes during cardiopulmonary bypass: relationship to postoperative neuropsychological function.

The relationship of changes in intraoperative QEEG and postoperative cognitive function was studied in 32 patients undergoing cardiac surgical procedures requiring cardiopulmonary bypass (CPB). All patients were anesthetized with a high dose narcotic technique in which CPB was carried out using moderate hypothermia. EEG recorded continuously throughout each procedure was analyzed using the neurometric technique. Neuropsychological (NP) evaluations were administered to all patients before, 1 week and 2-3 months postoperatively. A decrement in postoperative performance of 2 standard deviations in two or more tests from preoperative testing was defined as a new cognitive deficit. Of the patients studied, 40.6% demonstrated a new postoperative cognitive deficit at 1 week. At 2-3 months postoperatively, 28.1% continued to show a cognitive deficit. Discriminant analysis of the QEEG as a function of NP performance was calculated at select times during the surgical procedure. QEEG prediction of NP performance was just above chance at the 1 week comparison but excellent for the 2-3 month comparisons. This study suggests that with appropriate monitoring protocols, intraoperative QEEG may predict cognitive dysfunction experienced by patients 2-3 months postoperatively.

Anesthesia, General↗
PubMed1997

QEEG and neuropsychological profiles of patients prior to undergoing cardiopulmonary bypass surgical procedures.

Within our patient population undergoing cardiopulmonary bypass (CPB) surgery, evidence of pre-existing cortical dysfunction was highly prevalent, with 39.5% displaying QEEG and/or neuropsychological (NP) abnormality. These patients with pre-existing QEEG or NP abnormality were at increased risk for developing both short and long-term postoperative deficits in NP performance. Preoperative QEEG showed increased sensitivity and specificity over preoperative NP performance for predicting NP performance one week after surgery. One week after surgery NP deficits were quite common occurring in 40.6% of the patients. Two to three months after surgery evidence of continued NP performance deficits were still present in 28.1% of the patients. Preoperative NP performance predicted 3 month postoperative NP performance quite well, although preoperative QEEG proved equally effective.

Cardiac Surgical Procedures↗
PubMed1994

Early cardiac allograft failure after orthotopic heart transplantation.

Early cardiac graft failure has been reported to occur in 4-25% of patients undergoing orthotopic heart transplantation. To further elucidate the characteristics and prognosis of patients with graft failure, we retrospectively identified 10 patients from a series of 212 consecutive recipients with catastrophic graft dysfunction in the absence of acute cellular rejection, right ventricular failure secondary to pulmonary hypertension and technical factors. We present a case report and the experience from one transplant center, a review of the literature and possible strategies for the management of early graft failure. Mean onset of graft failure was 6.5 days (range intraoperative to 23 days). Multivariable analysis revealed a longer total ischemic time in patients with early graft dysfunction (200 +/- 14 vs. 166 +/- 4 min). No episodes of hyperacute rejection were observed. Pathologic changes noted on biopsy or autopsy included ischemia in 9 and vascular rejection in 1. The mortality at 60 days was 50%. Early use of aggressive mechanical and pharmacological support is described and appears to be important for graft salvage.

Adult↗
PubMed1989

Primary cardiac tumours--is there a place for cardiac transplantation?

Between 1979 and 1985, seven patients (five children and two adults) were treated for primary cardiac tumours other than benign atrial myxomas. There were five malignant neoplasms (two non-classifiable sarcomas, one haemangiosarcoma, one histiocytoma and one neurofibrosarcoma) and two benign tumours (fibromas). Echocardiography, cardiac catheterisation, computed tomography and magnetic resonance imaging provided diagnostic confirmation. The two patients with fibroma are alive and well 4 and 5 years after radical resection of the tumours from the interventricular septum. The patient with a neurofibrosarcoma underwent orthotopic cardiac transplantation and is well 5.5 years postoperatively with no evidence of residual disease or recurrence. One patient died awaiting a donor heart for transplantation. Another patient who was a candidate for heart and lung transplantation was found to have an unresectable tumour at the time of operation. One patient with sarcoma who underwent a successful emergency partial resection for relief of cardiac tamponade died 18 months later from widespread metastases. The seventh patient was inoperable due to multiple secondaries. It is concluded that radical resection of large, benign, cardiac tumours can give good results and that early cardiac transplantation probably offers the only hope for patients with malignant tumours of the heart.

Adolescent↗
PubMed1989

One-stage correction of interrupted aortic arch combined with heart-lung transplantation.

A technique for correction of interrupted aortic arch during heart-lung transplantation is described. This operation was performed in a 14-year-old patient with situs solitus, absent right atrioventricular connection, large atrial septal defect, ventricular septal defect, transposition of the great arteries, type B interrupted aortic arch, and severe pulmonary hypertension. The postoperative course was uneventful. Clinical, radiologic, and nuclear magnetic resonance investigation have shown evidence of good correction of the aortic arch anomaly. We concluded that donor tissue available during heart-lung transplantation is useful in correcting extracardiac anomalies.

Adolescent↗
PubMedDate not supplied

Pharmacology and biological efficacy of a recombinant, humanized, single-chain antibody C5 complement inhibitor in patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) induces a systemic inflammatory response that causes substantial clinical morbidity. Activation of complement during CPB contributes significantly to this inflammatory process. We examined the capability of a novel therapeutic complement inhibitor to prevent pathological complement activation and tissue injury in patients undergoing CPB. METHODS AND RESULTS: A humanized, recombinant, single-chain antibody specific for human C5, h5G1.1-scFv, was intravenously administered in 1 of 4 doses ranging from 0.2 to 2.0 mg/kg before CPB. h5G1.1-scFv was found to be safe and well tolerated. Pharmacokinetic analysis revealed a sustained half-life from 7.0 to 14.5 hours. Pharmacodynamic analysis demonstrated significant dose-dependent inhibition of complement hemolytic activity for up to 14 hours at 2 mg/kg. The generation of proinflammatory complement byproducts (sC5b-9) was effectively inhibited in a dose-dependent fashion. Leukocyte activation, as measured by surface expression of CD11b, was reduced (P<0.05) in patients who received 1 and 2 mg/kg. There was a 40% reduction in myocardial injury (creatine kinase-MB release, P=0.05) in patients who received 2 mg/kg. Sequential Mini-Mental State Examinations (MMSE) demonstrated an 80% reduction in new cognitive deficits (P<0.05) in patients treated with 2 mg/kg. Finally, there was a 1-U reduction in postoperative blood loss (P<0. 05) in patients who received 1 or 2 mg/kg. CONCLUSIONS: A single-chain antibody specific for human C5 is a safe and effective inhibitor of pathological complement activation in patients undergoing CPB. In addition to significantly reducing sC5b-9 formation and leukocyte CD11b expression, C5 inhibition significantly attenuates postoperative myocardial injury, cognitive deficits, and blood loss. These data suggest that C5 inhibition may represent a novel therapeutic strategy for preventing complement-mediated inflammation and tissue injury.

Antibodies, Monoclonal↗