Biomedical subjects

L S Czer

Publications and source records attributed to L S Czer.

At least 37 records · Page 2Linked to original sources

PubMed1996

Hearts from donors with chronic alcohol use: a possible risk factor for death after heart transplantation.

BACKGROUND: Careful donor and recipient selection are important factors for the success of heart transplantation. Currently, donors with a history of alcohol use are routinely accepted despite the potential deleterious effects of alcohol on the heart. METHODS: We examined the frequency of chronic alcohol use (> 2 ounces of pure alcohol daily for > or = 3 months) among organ donors and the outcome of the receipients after heart transplantation. Of 99 consecutive patients who underwent transplantation between December 1988 and August 1993 with an adequate donor history, 17 (17%) had a history of chronic alcohol use (alcohol group), and 82 (83%) did not (nonalcohol group). All recipients received triple-drug immunosuppression, and 10 to 14 days of OKT3. RESULTS: Survival rates at 1 and 2 years were significantly lower in the alcohol group (61% +/- 13% and 61$ +/- 13%) than in the nonalcohol group (95% +/- 3% and 91% +/-4%, p = 0.0001). Most deaths in the alcohol group occurred within 3 months after transplantation. The incidence of rejection episodes did not differ significantly. Fatal rejection occurred more frequently in the alcohol group and was associated with severe ventricular dysfunction before death. Cox multiple regression analysis identified donor alcohol use as an independent risk factor for death after heart transplantation. CONCLUSIONS: A substantial proportion (17%) of heart donors have a history of chronic alcohol use. The unfavorable early outcome of patients receiving hearts from alcoholic donors suggests the presence of a subclinical alcoholic cardiomyopathy before transplantation and poor tolerance of rejection episodes after transplantation. Larger prospective studies are needed to determine the mechanism of fatal rejection and whether such hearts can be used safely for transplantation.

Adolescent↗

PubMed1996

Surgical techniques for cardiac transplantation.

The surgical technique for cardiac transplantation was introduced by Lower and Shumway more than 30 years ago. It is known as "biatrial technique for cardiac transplantation" and has been used in more than 20,000 patients. However, since the early days of cardiac transplantation, atrial arrhythmias and atrioventricular conduction disturbances were noted so frequently that Dr. Barnard suggested a modification of the original technique to the present biatrial technique, in which the inferior vena cava orifice is enlarged with an atriotomy incision curving toward the base of the right atrial appendage, away from the sinus node. Atrial arrhythmias and other conduction abnormalities have, however, persisted and have resulted in the need for pacemaker insertion in a significant number of patients. Over the past years, with the more frequent use of transthoracic and transesophageal echocardiography, other abnormalities have been noted on follow-up of transplanted patients. These include tricuspid and mitral regurgitation, enlarged left and right atria with thrombus formation in the atrial suture line, asynchronous contraction of donor and recipient's atria, and right ventricular dysfunction in the early postoperative period. In the last 5 years, a new surgical technique for cardiac transplantation has been used in a few centers. This technique requires total excision of the recipient's heart and individual's caval and pulmonary vein anastomosis, "bicaval technique for cardiac transplantation." This technique seems to avoid the problems encountered with the biatrial technique. A comparison of the two surgical techniques, based on recently published surgical series, is presented.

Heart Diseases↗

PubMed1996

Isolated coronary artery transplantation in pigs: a new model to study transplantation arteriosclerosis and humoral rejection.

BACKGROUND: Graft atherosclerosis is a major cause of death after heart transplantation; its causes are multifactorial and poorly understood. To determine whether specific sensitization to coronary artery antigens is a contributing factor, we developed an isolated coronary artery allotransplantation model in pigs. METHODS: Of 46 Yucatan minipigs, 32 received a segment from a farm pig coronary artery into the common carotid artery (coronary allograft group) and 14 had a left to right common carotid artery autotransplant (carotid autograft group). No immunosuppressive drugs were given; all pigs received heparin for 5 days. We examined patency rates, histologic changes, and endothelial deposition of immunoglobulin G and M. RESULTS: In the coronary allograft group, patency rates were 100% (11 of 11) at 1 to 29 days, 20% (2 of 10) at 30 to 89 days, and 0% (0 of 11) after 90 days (overall 40.6%, 13 of 32). Histologic findings included endothelial cell hyperplasia, intimal proliferation, medial necrosis, adventitial inflammation, and ultimately luminal thrombosis. Deposition of immunoglobulin G and M was examined in the patent grafts and was seen in 90.9% (10 of 11) of grafts from days 1 to 29 and in the two patent but partially occluded grafts at 41 and 56 days. All carotid autografts except one (92.8%, 13 of 14) were patent up to 140 days and showed no or mild focal intimal thickening with normal media and adventitia. Deposition of immunoglobulin could not be detected in the autograft group. CONCLUSIONS: In this pig model of coronary artery allotransplantation, typical histologic findings of graft atherosclerosis are produced. Deposition of immunoglobulin G and M occurs early and is associated with endothelial cell hyperplasia and intimal proliferation. This model may be useful for the study of graft atherosclerosis and assessment of interventions designed to halt its progression.

Animals↗

PubMed1996

Revascularization alone or combined with suture annuloplasty for ischemic mitral regurgitation. Evaluation by color Doppler echocardiography.

To determine the effectiveness of revascularization alone or combined with mitral valve repair for ischemic mitral regurgitation, we performed color Doppler echocardiography intraoperatively before and after cardiopulmonary bypass in 49 patients (mean age, 70 +/- 9 years) with concomitant mitral regurgitation and coronary artery disease (triple vessel or left main in 88%; prior infarction in 90%). After revascularization alone (n = 25), the mitral annulus diameter (2.88 +/- 0.44 cm vs 2.88 +/- 0.44 cm), leaflet-to-annulus ratio (1.44 +/- 0.30 vs 1.44 +/- 0.29), and mitral regurgitation grade (1.7 +/- 0.9 vs 1.8 +/- 0.7) remained unchanged (p = NS, postpump vs prepump); mitral regurgitation decreased by 2 grades in only 1 patient (4%). After combined revascularization and mitral valve suture annuloplasty (Kay-Zubiate; n = 24), the annulus diameter decreased (to 2.57 +/- 0.45 cm from 3.11 +/- 0.43 cm), the leaflet-to-annulus ratio increased (to 1.46 +/- 0.25 from 1.20 +/- 0.21), and the mitral regurgitation grade decreased significantly (to 0.9 +/- 0.9 from 2.8 +/- 1.0) (p < 0.01); mitral regurgitation decreased by 2 grades or more (successful repair) in 75%. The origin of the jet correlated with the site of prior infarction (p < 0.05), being inferior in cases of posterior or inferior infarction (67%), and central or broad in cases of combined anterior and inferior infarction (70%). Despite a slightly higher 30-day mortality in the repair group (p = 0.10), there was no significant difference in survival between the 2 surgical groups at 5 years or 8 years. Therefore, in this study of patients with mitral regurgitation and coronary artery disease, reduction in regurgitation grade with revascularization alone was infrequent. Concomitant suture annuloplasty significantly reduced regurgitation by reestablishing a more normal relationship between the leaflet and annulus sizes. The failure rate after suture annuloplasty was 25%; alternative repair techniques such as ring annuloplasty may have a lower failure rate.

Aged↗

PubMed1995

Atrial emptying with orthotopic heart transplantation using bicaval and pulmonary venous anastomoses: a magnetic resonance imaging study.

OBJECTIVES: We hypothesized that orthotopic heart transplantation with bicaval and pulmonary venous anastomoses preserves atrial contractility. BACKGROUND: The standard biatrial anastomotic technique of orthotopic heart transplantation causes impaired function and enlargement of the atria. Cine magnetic resonance imaging (MRI) allows assessment of atrial size and function. METHODS: We studied 16 patients who had undergone bicaval (n = 8) or biatrial (n = 8) orthotopic heart transplantation without evidence of rejection and a control group of 6 healthy volunteers. For all three groups, cine MRI was performed by combining coronal and axial gated spin echo and gradient echo cine sequences. Intracardiac volumes were calculated with the Simpson rule. Atrial emptying fraction was defined as the difference between atrial diastolic and systolic volumes, divided by atrial diastolic volume, expressed in percent. All patients had right heart catheterization. RESULTS: Right atrial emptying fraction was significantly higher in the bicaval (mean [+/- SD] 37 +/- 9%) than in the biatrial group (22 +/- 11%, p < 0.05) and similar to that in the control group (48 +/- 4%). Left atrial emptying fraction was significantly higher in the bicaval (30 +/- 5%) than in the biatrial group (15 +/- 4%, p < 0.05) and significantly lower in both transplant groups than in the control group (47 +/- 5%, p < 0.05). The left atrium was larger in the biatrial than in the control group (p < 0.05). Cardiac index, stroke index, heart rate and blood pressure were similar in the transplant groups. CONCLUSIONS: Left and right atrial emptying fractions are significantly depressed with the biatrial technique and markedly improved with the bicaval technique of orthotopic heart transplantation. The beneficial effects of the latter technique on atrial function could improve allograft exercise performance.

Adult↗

PubMed1995

Improved left atrial transport and function with orthotopic heart transplantation by bicaval and pulmonary venous anastomoses.

Orthotopic heart transplantation (OHT) with bicaval and pulmonary venous anastomoses avoids the large atrial anastomoses of the standard biatrial technique. To determine whether the bicaval technique improves atrial performance, we used Doppler echocardiography to study 13 patients with bicaval OHT, 15 with biatrial OHT, and 8 normal subjects. All were in sinus rhythm and free of rejection. Left atrial size, transmitral (M) and late diastolic (A) mitral flow velocity integrals were measured. Atrial transport (A/M, %) and atrial ejection force (kilodynes, calculated from peak A-wave velocity and mitral orifice area) were assessed. Left atrial dimensions in the bicaval (4.3 +/- 0.5 cm) and biatrial groups (4.9 +/- 0.9 cm) were larger than in controls (3.3 +/- 0.8 cm, p < 0.05). Left atrial transport (37% +/- 12% and 35% +/- 12%) and ejection force (14.1 +/- 6.9 kdyne and 10.2 +/- 7.8 kdyne) were similar in the bicaval group and controls (p not significant) but were significantly lower in the biatrial group (20% +/- 19% and 3.6 +/- 4.0 kdynes, p < 0.05). The bicaval and pulmonary venous technique of OHT produces more physiologic atrial function compared with the biatrial technique as evidenced by greater atrial ejection force and more normal atrial transport.

Adult↗

PubMed1995

Wolff-Parkinson-White syndrome in a cardiac allograft.

A 61-year-old man underwent orthotopic heart transplantation for end-stage ischemic cardiomyopathy. The donor presented with Wolff-Parkinson-White syndrome and the allograft was successfully transplanted. The accessory pathway was interrupted postoperatively by radiofrequency current catheter ablation, and the patient is clinically well and free of preexcitation 24 months later.

Cardiomyopathies↗

PubMed1995

Permanent pacemaker for rejection episodes after heart transplantation: a poor prognostic sign.

BACKGROUND: The development of arrhythmias early or late after heart transplantation has been associated with acute and chronic rejection. This study aims to document the importance of this relationship and its value as a prognostic sign in those patients who required a permanent pacemaker for rejection episodes. METHODS: A retrospective analysis of 158 orthotopic heart transplantations performed in 157 patients between December 1988 and April 1995 was done. The clinical course and the outcome of 6 patients who underwent insertion of a permanent pacemaker for bradyarrhythmias caused by acute or chronic allograft rejection were compared with the course and outcome of 9 patients who had pacemaker placement as a result of sinus node dysfunction not associated with rejection. RESULTS: The mortality rate was 100% for patients whose indication for permanent pacing was severe acute or chronic rejection. Conversely, 8 of the 9 patients who underwent pacemaker placement for sinus node dysfunction not associated with rejection are long-term survivors; the one late death was due to a noncardiac cause. CONCLUSIONS: We observed a strong relationship between bradyarrhythmias requiring a permanent pacemaker and severe acute or chronic allograft rejection. This association suggests a poor prognosis and indicates that these patients should be managed aggressively. Such management includes close immunologic surveillance for cellular and humoral rejection, increased frequency of endomyocardial biopsies and coronary angiography, and early consideration for retransplantation.

Acute Disease↗

PubMed1995

Heart transplantation for Chagas' cardiomyopathy.

We present 2 patients who underwent orthotopic heart transplantation for end-stage Chagas' cardiomyopathy. Despite immunosuppressive therapy, postoperative prophylaxis with nifurtimox appeared to prevent Trypanosoma cruzi reactivation. Neither patient has shown signs of Chagas' myocarditis, and both are clinically well 12 and 72 months after transplantation. The successful outcome of our patients suggests that heart transplantation is a reasonable therapeutic option in patients with end-stage Chagas' cardiomyopathy.

Adult↗

PubMed1995

Superior vena cava stenosis after orthotopic heart transplantation: complication of an alternative surgical technique.

Superior vena cava stenosis presented as a postoperative complication of orthotopic heart transplantation in a patient in whom a new surgical technique was used. This alternative technique consists of total excision of the recipient's atria, with donor heart implantation performed using bicaval and pulmonary venous anastomoses. This rare complication required surgical repair 1 month after transplantation. The patient remains well on long-term follow-up. The pathogenesis, surgical management and modifications of the alternative technique to prevent this potentially serious complication are discussed.

Constriction, Pathologic↗

PubMed1995

Survival of acute intestinal infarction after cardiac transplantation.

We report the case of a 52-year-old male who underwent total orthotopic heart transplantation for end-stage ischemic cardiomyopathy. The postoperative course was complicated by acute intestinal infarction which was diagnosed after surgical exploration, and treated with a subtotal colectomy with Brooke ileostomy and closure of the distal sigmoid three days posttransplant. The patient survived with nutritional support and broad antibiotic prophylaxis. Review of the literature on acute abdominal complications after operations involving cardiopulmonary bypass suggests that such complications are usually fatal. Detection and diagnosis may be obscured and treatment complicated by immunosuppression after cardiac transplantation. Because of the poor prognosis without appropriate management, a high level of suspicion, early and aggressive diagnostic measures, and swift surgical intervention are essential to survival.

Colon↗

PubMed1995

Heart transplantation after repair of postinfarction ventricular septal defect.

A 68 year-old man underwent surgical repair of a ventricular septal defect following an acute myocardial infarction. Recurrent interventricular septal rupture with significant left-to-right shunting led to progressive deterioration in cardiac function and intractable heart failure. The patient underwent orthotopic heart transplantation three months after his initial operation, and he is clinically well sixteen months after transplantation.

Aged↗

PubMed1994

Combined heart and kidney transplantation with allografts from the same donor.

We present the cases of 3 patients who underwent simultaneous heart and kidney transplantation using allografts from the same donor. This combined approach offers a reasonable option for patients with coexisting end-stage heart and kidney disease. A review of all previously reported cases suggests that survival is similar to that of single-organ transplantation. In addition, there appears to be a low incidence of rejection when multiple allografts from the same donor are used. The heart and kidney can and frequently do reject asynchronously, so rejection monitoring and surveillance should be carried out separately for each transplanted organ.

Adult↗

PubMed1994

Alternative technique for orthotopic heart transplantation.

An alternative technique for orthotopic heart transplantation is described. The principle consists of total excision of the recipient's right atrium with donor heart implantation performed using bicaval anastomoses; the left atrium is done in the standard fashion. This approach is technically simple and preserves the anatomic and physiologic function and integrity of the right atrium, especially the conduction system.

Adult↗

PubMed1994

Heart transplantation for Q fever endocarditis.

A 30-year-old man underwent aortic and mitral valve replacement for the treatment of Q fever endocarditis. Postoperatively, paravalvular leak of the mitral prosthesis, progressive deterioration in cardiac function, and intractable heart failure developed. As a result, the patient underwent orthotopic heart transplantation 15 months after his initial valve operation. The patient is clinically well 14 months after transplantation.

Adult↗

PubMed1994

Orthotopic heart transplantation with bicaval and pulmonary venous anastomoses.

We present our experience with an alternative technique for orthotopic heart transplantation. It consists of total excision of the recipient's atria, with the donor's heart implantation performed using bicaval end-to-end anastomoses as well as pulmonary venous anastomoses. Forty consecutive patients receiving transplants in this fashion were compared with 64 patients who underwent orthotopic transplantation with the standard technique. The incidence of postoperative tricuspid regurgitation was reduced in patients receiving transplants with the new surgical approach (p = 0.003). In addition, the need for pacemaker implantation for severe bradyarrhythmia in the early (0 to 6 weeks) posttransplantation period (p = 0.003) was eliminated. Although not statistically significant, there was a trend in the reduction of postoperative mitral regurgitation in patients who received transplants by the modified technique. Based on this experience, we believe this modified technique for orthotopic heart transplantation has an anatomic and physiologic advantage that may improve long-term hemodynamic results.

Anastomosis, Surgical↗

PubMed1994

Technical considerations of a new technique for orthotopic heart transplantation. Total excision of recipient's atria with bicaval and pulmonary venous anastomoses.

An alternative technique for orthotopic heart transplantation is described. It consists of total excision of the recipient's atria with donor heart transplantation performed using bicaval end-to-end anastomosis, as well as pulmonary venous anastomoses. Thus, total atrial as well as ventricular transplantation is performed. This new surgical approach is technically simple and preserves the anatomic size, geometric configuration and physiologic function of the atria. This technique has the potential to improve the long-term hemodynamic results in heart transplant patients as it reduces the incidence of postoperative atrioventricular valve regurgitation. In addition, the incidence of early posttransplant bradyarrhythmias (within 4 to 6 weeks after transplantation) that require the insertion of a permanent pacemaker is also significantly reduced. This report describes some technical guidelines for harvesting the donor heart, as well as for the implantation of the cardiac allograft, in order to avoid the development of serious intraoperative and postoperative complications directly associated with this technique.

Anastomosis, Surgical↗

PubMed1992

Doppler assessment of prosthetic valve orifice area. An in vitro study.

BACKGROUND: Although Doppler echocardiography has been shown to be accurate in assessing stenotic orifice areas in native valves, its accuracy in evaluating the prosthetic valve orifice area remains undetermined. METHODS AND RESULTS: Doppler-estimated valve areas were studied for their agreement with catheter-derived Gorlin effective orifice areas and their flow dependence in five sizes (19/20-27 mm) of St. Jude, Medtronic-Hall, and Hancock aortic valves using a pulsatile flow model. Doppler areas were calculated three ways: using the standard continuity equation; using its simplified modification (peak flow/peak velocity); and using the Gorlin equation with Doppler pressure gradients. The results were compared with Gorlin effective orifice areas derived from direct flow and catheter pressure measurements. Excellent correlation between Gorlin effective orifice areas and the three Doppler approaches was found in all three valve types (r = 0.93-0.99, SEE = 0.07-0.11 cm2). In Medtronic-Hall and Hancock valves, there was only slight underestimation by Doppler (mean difference, 0.003-0.25 cm2). In St. Jude valves, however, all three Doppler methods significantly underestimated effective orifice areas derived from direct flow and pressure measurements (mean difference, 0.40-0.57 cm2) with differences as great as 1.6 cm2. In general, the modified continuity equation calculated the largest Doppler areas. When orifice areas were calculated from the valve geometry using the area determined from the inner valve diameter reduced by the projected area of the opened leaflets, Gorlin effective orifice areas were much closer to the geometric orifice areas than Doppler areas (mean difference, 0.40 +/- 0.31 versus 1.04 +/- 0.20 cm2). In St. Jude and Medtronic-Hall valves, areas calculated by either technique did not show a consistent or clinically significant flow dependence. In Hancock valves, however, areas calculated by both the continuity equation and the Gorlin equation decreased significantly (p less than 0.001) with low flow rates. CONCLUSIONS: Doppler echocardiography using either the continuity equation or Gorlin formula allows in vitro calculation of Medtronic-Hall and Hancock effective valve orifice areas but underestimates valve areas in St. Jude valves. This phenomenon is due to localized high velocities in St. Jude valves, which do not reflect the mean velocity distribution across the orifice. Valve areas are flow independent in St. Jude and Medtronic-Hall prostheses but decrease significantly with low flow in Hancock valves, suggesting that bioprosthetic leaflets may not open fully at low flow rates.

Aortic Valve↗