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Biomedical subjects

W T Vigneswaran

Publications and source records attributed to W T Vigneswaran.

At least 19 recordsLinked to original sources

Low rate of acute lung allograft rejection after the use of daclizumab, an interleukin 2 receptor antibody.

BACKGROUND: The incidence and the severity of acute lung allograft rejection has been linked to the development of bronchiolitis obliterans syndrome. Therefore, we investigated the effects of daclizumab, a humanized monoclonal antibody directed against the alpha subunit of the interleukin 2 receptor, in reducing acute rejection after transplantation. METHODS: We retrospectively evaluated 27 patients who received daclizumab as induction immunosuppression and compared them with a historical control group of 34 patients. Both groups received similar immunosuppressive regimens involving tacrolimus, prednisone, and either azathioprine or mycophenolate mofetil. All patients received cytomegalovirus and aspergillus prophylaxis. RESULTS: Twenty-one patients in the control group and 22 patients in the daclizumab group were available for analysis at 6 months after lung transplantation. Ten (48%) patients in the control group had at least grade 2 acute rejection compared with four (18%) in the daclizumab group (P<0.04). The incidence of infection was similar in both groups. One patient in each group developed posttransplant lymphoproliferative disease. CONCLUSION: Therapy with daclizumab resulted in a significant decrease in the incidence of grade 2 or greater acute rejection after lung transplantation compared with historical controls. There seems to be no increase in the incidence of adverse effects in the patients treated with daclizumab.

Acute Disease↗

Quantification of cytomegalovirus (CMV) viral load by the hybrid capture assay allows for early detection of CMV disease in lung transplant recipients.

BACKGROUND: We prospectively compared the hybrid capture system (HCS) assay with conventional cell culture and shell vial assay for the detection of cytomegalovirus (CMV) infection and disease in the lung transplant population. METHODS: Between January 1999 and February 2000, 34 lung transplant patients at Loyola University Medical Center, who were considered to be at risk for CMV disease, underwent surveillance testing for CMV cell culture, shell vial assay and HCS assay according to a pre-determined schedule. In addition, bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy were performed at regular intervals and for clinical indications. All BAL samples were sent for CMV cultures and biopsy specimens were analyzed for histopathologic evidence of CMV by immunoperoxidase staining using antibody to early immediate nuclear antigen. RESULTS: Ten patients developed CMV disease/syndrome during the course of the study. The sensitivity, specificity, positive predictive value and negative predictive value were >90% for the HCS assay. The sensitivity of the HCS assay (90%) was statistically significantly higher than the sensitivity of either the SV assay (40%) or the cell culture (50%). In addition, the HCS assay was able to detect CMV 50 +/- 67 days prior to clinical evidence of CMV disease and an average of 36 days prior to the other detection techniques. CONCLUSION: The HCS assay is a sensitive diagnostic technique able to reliably detect CMV disease earlier than other diagnostic methods in the lung transplant population. Future studies may be able to evaluate whether pre-emptive anti-viral therapy targeted to specific viral loads using the HCS assay will be beneficial in preventing morbidity associated with CMV disease.

Adult↗

Pericardial mesothelioma.

Primary pericardial mesothelioma is a rare but lethal disease. Altogether there are about 150 cases reported in the literature. In most cases the diagnosis is made at autopsy or postoperatively. Clinical signs and symptoms are typically nonspecific and are similar to compromised cardiac function. Surgical resection remains the main treatment modality. When the disease is localized and completely resected, long-term survival can result. Most often the tumor invades the myocardium or the great vessels and therefore is at best palliative in relieving pericardial tamponade or constriction. Addition of chemotherapy or radiation has been disappointing. Newer therapeutic approaches for malignant pleural mesothelioma are likely to influence the treatment of pericardial mesothelioma in the future.

Antineoplastic Agents↗

Cardiopulmonary bypass increases coronary IL-8 in diabetic patients without evidence of reperfusion injury.

BACKGROUND: Endothelin-1 (ET-1) has been shown to be a potent agonist for monocyte production of the neutrophil chemotactic cytokine interleukin-8 (IL-8). We have shown that diabetic patients demonstrate elevated coronary ET-1 after coronary artery bypass grafting (CABG). We hypothesized that these same diabetic patients would manifest elevated coronary IL-8 and conjugated diene concentrations (an index of reperfusion injury). METHODS: Sixteen patients [9 nondiabetics and 7 type II diabetics] underwent nonemergent CABG. The two groups did not differ significantly in preoperative ejection fraction, number of vessels bypassed, or cross-clamp time. Coronary sinus samples were obtained prior to cardioplegic arrest (baseline) and at 1 and 15 min after reperfusion periods A and B (A, reperfusion of native coronaries + LIMA; B, reperfusion of saphenous vein grafts in addition to native coronary system + LIMA). Plasma samples were analyzed for IL-8 (ELISA) and conjugated dienes (spectrophotometry). RESULTS: Initially after reperfusion, IL-8 in both groups was significantly lower than precardioplegia values. In reperfusion B, only the diabetic group demonstrated a significant increase in IL-8 concentrations at 1 and 15 min compared to nondiabetics. Conjugated diene levels were significantly higher in diabetics at each time point than nondiabetics. CONCLUSIONS: This study demonstrates an early decrease in IL-8 in both groups, most likely related to depressed production secondary to hypothermia. The subsequent elevation in IL-8 only in the diabetic group was seen without concomitant conjugated diene elevation. While no evidence of reperfusion injury was demonstrated in this time frame, the elevation of IL-8 in diabetics after CABG may contribute to later infiltration and associated oxidative damage.

Alkenes↗

Elevated coronary endothelin-1 but not nitric oxide in diabetics during CABG.

BACKGROUND: After coronary artery bypass grafting procedures, a higher incidence of morbidity and mortality has been reported in diabetic patients. We tested whether coronary artery bypass grafting in diabetics affects the endothelin-1 and nitric oxide coronary effluent profile during reperfusion. METHODS: Twenty-one consecutive patients (9 with type II diabetes mellitus, 12 non-diabetics) underwent coronary artery bypass grafting by one surgeon. The two groups did not differ in preoperative ejection fraction, Parsonnet score, number of vessels bypassed, or cross-clamp time. Each patient was treated in the same intraoperative manner with single atrial, aortic, and antegrade and retrograde cardioplegia (CPL) cannulas. Cold CPL arrest was by antegrade and retrograde infusion of modified Buckberg CPL solution. Warm CPL solution was infused before reperfusion. Coronary sinus blood samples were obtained for estimation of endothelin-1 and nitrite plus nitrate before CPL arrest and at 1 and 15 minutes after each of 2 reperfusion periods. RESULTS: In diabetics, endothelin-1 was significantly increased at all reperfusion times as compared with non-diabetics. Nitrite plus nitrate levels were significantly higher in patients with diabetes than in those without, but did not change with time in either of the groups. CONCLUSIONS: Reperfusion after CPL during coronary artery bypass grafting procedure can trigger the release of endothelin-1 in patients with diabetes mellitus. This may favor increased vascular tone or positive inotropic responses after coronary artery bypass grafting and may contribute to significant cardiovascular consequences in diabetic patients.

Coronary Artery Bypass↗

Electrophysiological and clinical comparison of two temporary pacing leads following cardiac surgery.

Temporary pacing leads are invaluable in diagnosis and treatment of arrhythmia after cardiac surgery. The ideal lead possesses reliable pacing and sensing capabilities throughout the postoperative period. Ease of handling and a low complication rate are essential. This study compares a new lead (Medtronic model #6492) to a temporary pacemaker lead established in clinical use (Medtronic model #6500). One lead of each type was placed in the right atrium and ventricle in 33 patients undergoing elective coronary revascularization. Pacing function was measured on the first and fourth postoperative days. Lead complications were documented. On day 1, there was no statistical difference between lead types in terms of pacing (voltage threshold, current threshold), impedance, or sensing (P wave amplitude, R wave amplitude). On day 4, both leads showed an increase in pacing threshold and a decrease in sensing ability. The only statistical difference between lead types was in atrial sensing on day 4, as measured by the P wave amplitudes (1.95 +/- 0.18 V for model 6492 vs 1.40 +/- 0.14 V for model 6500, P < 0.05). Two leads of each model failed to pace in the ventricular position and one lead in each model in the atrial position. There were no complications attributable to either pacemaker lead. We found that both lead types were reliable and functioned well. The Medtronic Model #6492 lead demonstrated better long-term sensing, although in this study the difference was not clinically significant.

Arrhythmias, Cardiac↗

Lung transplantation at Loyola University Medical Center.

The Loyola Lung Transplant Program shows a long record of offering transplants to suitable recipients, with good clinical results. The overall one-year survival rate was 84% for 53 lung transplant recipients in 1998-99. Our local perception on donor management appears to be successful at increasing donor organ availability. In addition, continuous evolution in posttransplant care and willingness to utilize newer immunosuppressive agents has reduced our incidence of acute rejection episodes to 23% during the past 2 years. Time will tell if there is also a measurable reduction in bronchiolitis obliterans syndrome. Finally, longitudinal research on QOL after lung transplantation continues to buoy our spirits based on patient acceptance and satisfaction with results. We continue to be strong advocates for transplantation and organ donation.

Communicable Diseases↗

Single-stage, bilateral, video-assisted thoracoscopic lung volume reduction surgery for end-stage emphysema.

The reintroduction of lung volume reduction surgery has provided functional improvement for selected patients afflicted with end-stage emphysema. Evolution of the operation from a median sternotomy approach to the two-stage video-assisted thoracoscopic surgical technique in our experience has resulted in a faster return to full activity. Nineteen patients underwent video-assisted thoracoscopic lung volume reduction surgery between July 1995 and August 1997. The 12 men and 7 women in the study had an average age of 63.7 years. All patients were evaluated preoperatively with computed tomography of the chest, radionuclide lung perfusion scan, left ventricular stress test, right heart catheterization, and a monitored rehabilitation program. In 15 patients the operation was performed as a bilateral single-stage procedure. The operation involved resection of wedges from the upper lobes and in 10 of these patients from the lower lobes as well. In all patients the estimated operative blood loss was less than 150 ml. The mean operative time was 177 minutes (range 115-235 minutes). The mean length of hospital stay was 10.8 days (median 11 days, range 5-24 days). At 2 to 3 months' follow-up increases were noted in the FEV1 (51%), PaO2 (27%), and 6-minute walk distance (18%); and there was a decrease in total lung capacity and respiratory volume. No significant change was observed in carbon monoxide diffusion in the lung. Morbidity included persistent air leaks in three patients and refractory supraventricular tachyarrhythmia in one. There were no perioperative deaths. We therefore recommend this technical modification to reduce operating time and blood loss without compromising surgical exposure or outcome.

Endoscopy↗

Video-assisted thoracoscopic left ventricular thrombectomy and coronary artery revascularization.

Advances in video-assisted techniques in the fields of general and thoracic surgery have led to the application of this technology in experimental and clinical cardiac surgery. Visualization of intracardiac anatomy and pathology allows procedures to be performed without violation of ventricular muscle, thus preserving myocardial function. We present the case of a patient with a recent myocardial infarction, found to have a large left ventricular thrombus on echocardiogram. By applying thoracoscopic surgical technology we successfully removed the thrombus during emergency coronary artery revascularization and avoided myotomy.

Coronary Thrombosis↗

Diabetic patients produce an increase in coronary sinus endothelin 1 after coronary artery bypass grafting.

Diabetes is associated with altered vascular responses, and diabetic patients demonstrate increased morbidity and mortality after coronary artery bypass grafting (CABG). We tested whether endothelin (ET)-1 levels in this patient population differed from those in nondiabetic subjects after CABG. Of 14 consecutive patients who underwent CABG by the same surgeon, 7 had type 2 diabetes and 7 were nondiabetic. The two groups did not differ significantly in preoperative ejection fraction, number of vessels bypassed, cross-clamp time, or Parsonnet's score. Coronary sinus blood samples were obtained before cardioplegic arrest and then obtained at 1 and 15 min after each of two reperfusion periods: reperfusion A (native coronary perfusion plus the left internal mammary artery), reperfusion B (saphenous vein graft perfusion). ET-1 was significantly increased at all reperfusion time points in diabetic patients compared with nondiabetic patients. In diabetic patients, reperfusion after CABG can trigger the release of ET-1, which may be a contributing factor in the increased cardiac morbidity seen in this patient population.

Coronary Artery Bypass↗

Giant azygos vein varix.

Primary anomalies of the azygos vein generally result from intrathoracic tumor compression or inferior vena caval interruption with azygos vein continuation. Vascular malformations, although uncommon, can frequently mimic solid tumors and present as middle or posterior mediastinal masses. We present the case of an isolated giant azygos vein varix in an asymptomatic patient. Preoperative computed tomography and magnetic resonance imaging were not diagnostic in evaluating this patient's anatomy.

Aged↗

Single-stage bilateral, video-assisted thoracoscopic lung volume reduction operation.

Lung volume reduction (LVR) produces significant clinical and objective improvement in selected patients with diffuse emphysema. Unilateral and bilateral approaches have been successfully employed. A median sternotomy approach is the standard for bilateral LVR, whereas video-assisted thoracoscopy has been used to perform unilateral LVR. Encouraging video-assisted thoracoscopic results with sequential, staged, bilateral LVR have been shown. This report describes an alternate technique of single-stage, bilateral LVR for end-stage emphysema.

Emphysema↗

Right and left ventricular remodeling after orthotopic single lung transplantation for end-stage emphysema.

BACKGROUND: Orthotopic single lung transplantation (LTX) is now an established treatment modality for patients with end-stage emphysema. LTX has been shown to cause unloading of the right ventricle with improvement in right ventricular (RV) structure and function both immediately and up to weeks after surgery, mostly in patients with severe pulmonary hypertension and decreased RV function. Long-term effects of lung transplantation on both RV and left ventricular (LV) anatomy and function, however, are not well known. METHODS: Seventeen patients undergoing LTX for end-stage emphysema and preserved RV function underwent serial electron beam computed tomography RV and LV function studies before, 3 months after, 1 year after, and 2 years after transplantation. Right-sided heart catheterization was performed before transplantation and at 1 and 2 years follow-up. RESULTS: RV end systolic volume decreased significantly (-15.5%), and RV ejection fraction increased significantly (+16%) in the first 3 months after LTX. This change was paralleled by a decrease in pulmonary pressure and vascular resistance, indicating a permanent RV unloading. This improvement was maintained up to 2 years after LTX. LV end-diastolic volume (+25%), LV stroke volume (+29%), and LV muscle mass (+28%) increased significantly in the first 3 months after LTX. This remodeling was maintained during the 2-year follow-up. CONCLUSIONS: Significant changes in cardiac anatomy and function occur shortly after LTX, most likely as a consequence of adaptation to a new hemodynamic state in patients with well preserved RV function before LTX. Furthermore, these acute changes persist for at least 2 years after LTX.

Adult↗

Paraffin plombage of the chest revisited.

Complications related to previous thoracic plombage procedures are not uncommon. The management of these complication can be challenging. We present a patient who had a partial resection of the left upper lobe, a seven-rib thoracoplasty, and paraffin wax plombage 38 years previously, in whom a chest wall mass and a discharging sinus developed. She underwent excision and debridement of the paraffin wax mass followed by serratus anterior and latissimus dorsi pedicled muscle intrathoracic transposition. Follow-up at 2 years revealed excellent cosmetic and functional results.

Aged↗

Ventricular remodeling after orthotopic cardiac transplantation.

OBJECTIVE: To determine quantitative changes in ventricular chamber volumes and left ventricular mass after orthotopic cardiac transplantation. MATERIAL AND METHODS: Right ventricular and left ventricular chamber volumes and left ventricular muscle mass were quantified by electron beam computed tomography in 10 patients at 1 month and 12 months after orthotopic cardiac transplantation. RESULTS: During the study period, the mean right ventricular end-diastolic volumes increased from 117 +/- 26.1 cc to 143 +/- 25.3 cc (P < 0.005), and the mean left ventricular end-diastolic volumes increased from 90 +/- 20.6 cc to 117 +/- 27.3 cc (P < 0.001). Left ventricular stroke volume increased from 63 +/- 16.5 cc at 1 month to 78 +/- 19.8 cc by 12 months (P < 0.005). These changes were associated with a concurrent reduction in global left ventricular muscle mass from 168 +/- 25.2 g to 145 +/- 16.3 g (P < 0.01). The left ventricular end-diastolic volume/mass ratio, an index of wall tension, was abnormally low at 1 month but was in the normal range by 12 months (P < 0.0005). Both left ventricular and right ventricular ejection fractions were normal at all times and not significantly changed between the 1-month and 12-month studies. CONCLUSION: Significant right and left ventricular remodeling occurs between 1 month and 12 months after orthotopic cardiac transplantation, with progressive cavity dilatation but reduction in global left ventricular muscle mass. These adjustments, especially in the left ventricle, tend to reduce the volume/mass ratio by 1 year and are compatible with normalization of ventricular wall tension between the early and late scan dates. Routine clinical measurements of ejection fraction alone mask the almost parallel increases in stroke volume and end-diastolic volume during the first 12 months after orthotopic cardiac transplantation.

Adult↗

Extended esophagectomy in the management of carcinoma of the upper thoracic esophagus.

Upper thoracic esophageal tumors adjacent to the trachea often require a preliminary thoracotomy to accomplish resection. Between January 1985 and July 1992, 49 consecutive patients (38 men and 11 women) underwent extended esophagectomy for esophageal cancer where the neoplasm was mobilized through an initial right thoracotomy and then resected and reconstructed through an abdomino-cervical approach. Ages ranged from 40 to 80 years (median 63.4 years). The tumor was located in the upper third of the thoracic esophagus in 44 patients and in the middle third in five. Thirty-three patients had squamous cell carcinoma, 14 had adenocarcinoma, and two had adenosquamous cell carcinoma. Complications occurred in 35 patients (71.4%) and included anastomotic leak in 15, vocal cord paralysis in 11, atrial arrhythmia in nine, pneumonia in six, wound infection in five, and postoperative bleeding in one. Three patients required tracheostomy. There was one postoperative death (2.0%). Median survival was 0.9 years (range 1 month to 5.1 years). Thirty-one patients were alive at the time this article was written, 28 without evidence of cancer. Cause of death was recurrent disease in 13 patients, unrelated to cancer in three, and unknown in one. Overall actuarial 3- and 5-year survivals were 48.6% and 18.2%, respectively. Four-year survival for stage II disease was 44.6% as compared to 24.9% for stage III (p < 0.02). The presence of lymph node metastases significantly affected survival. Three-year survival for patients with N0 disease was 77.9% compared with 20.9% for patients with N1 disease (p < 0.01). Age, sex, and cell type had no effect on survival. Ten patients had late dysphagia, four had gastroesophageal reflux, and one had dumping symptoms. Although associated with significant morbidity, we conclude that extended esophagectomy is an acceptable method of management for tumors of the upper thoracic esophagus. Mortality is low, and long-term results are reasonable.

Adenocarcinoma↗

Transhiatal esophagectomy for carcinoma of the esophagus.

One hundred thirty-one patients (107 men and 24 women) underwent transhiatal esophagectomy for carcinoma of the esophagus. Median age was 65.3 years (range, 30 to 89 years). Signs and symptoms were present in 130 patients, which included dysphagia in 96 (73.3%) and weight loss (median, 7.7 kg) in 52 (39.7%). The cancer involved the gastroesophageal junction in 94 patients, the lower half of the intrathoracic esophagus in 25, the upper half in 10, and multiple sites in 2. An adenocarcinoma was present in 101 patients (77.1%), squamous cell carcinoma in 29 (22.1%), and adenosquamous cell in 1 (0.8%). The cancer was classified as stage 0 in 4 patients, stage I in 16, stage IIA in 26, stage IIB in 18, stage III in 65, and stage IV in 1. The stomach was used to replace the esophagus in all patients. Operative mortality was 2.3%. Anastomotic leak developed in 32 patients; 6 leaks were not clinically significant, 12 healed with drainage alone, and 14 required further surgical intervention. Follow-up ranged from 1 month to 6.7 years (median, 1.4 years). Currently, 42 patients are alive, 34 without evidence of recurrence. Overall 5-year survival was 20.8% and varied according to stage. Five-year survival was 47.5% for patients with stage I disease compared with 37.7% for patients in stage II and only 5.8% 4-year survival for patients in stage III. Cell type also influenced survival. Five-year survival for patients with adenocarcinoma was 27.1% compared with zero for patients with squamous cell carcinoma (p < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗