Heart transplantation in Chagas' disease. 10 years after the initial experience.

BACKGROUND: Heart transplantation (HT) as a therapeutic option for end-stage chronic Chagas' heart disease (CCHD) is controversial. Reactivation of Trypanosoma cruzi infection and recurrence of the disease in the allograft are likely to occur. Furthermore, active myocarditis has been reported to predispose patients to an increased incidence and severity of rejection. METHODS AND RESULTS: We prospectively investigated the long-term follow-up of 10 patients with CCHD who underwent HT. Immunosuppression was based on cyclosporine A and azathioprine. T cruzi reactivation was prevented with benzonidazole. Besides allograft rejection surveillance, T cruzi infection was monitored through blood tests, myocardial biopsies, and serological tests. Over a mean follow-up period of 34 +/- 38 months (range, 73 to 124 months), 7 patients are alive and in NYHA functional class I. Life expectancy was 78% for the second year and 65% for 10 years. Rejection was less frequent in chagasic than in age- and sex-matched control patients (mean +/- SD, 1.60 +/- 1.26 versus 5.70 +/- 1.89 episodes per patient, respectively; P = .0001); decreased severity of rejection was also observed (P = .006). T cruzi parasitemias detected on three occasions were successfully treated with benzonidazole. There were no signs of recurrence of the disease in the allograft. CONCLUSIONS: These results suggest an important role of HT in the treatment of CCHD. There was a low frequency of T cruzi infection reactivation and no signs of recurrence of the disease in the allograft. The surprisingly decreased rejection incidence and severity require further studies for elucidation.

[Aneurysm of left ventricle associated with post-infarction interventricular communication]. / Aneurisma de ventrículo esquerdo associado à comunicação interventricular pós-infarto.

The authors report two cases of left ventricular aneurysm associated with post-infarction ventricular septal rupture. This rare association, usually aggravated by high mortality, received successful surgical treatment.

Microscopic study of normal parietal pericardium and unimplanted Puig-Zerbini pericardial valvular heterografts.

This investigation used light microscopy and transmission and scanning electron microscopy to study native human and bovine parietal pericardium, glutaraldehyde-fixed bovine pericardial patch-grafts, and bovine pericardial cusps of unimplanted Incor or Puig - Zerbini heart valves. The primary objective was to obtain a data base for the future evaluation of postimplantation structural alteration in this valve and in other cardiac valvular bioprostheses constructed of pericardium. The mesothelial cell layer in normal pericardium was best preserved in the bovine tissue. In both bovine patch-grafts and Puig - Zerbini valvular cusps, the serosal surface usually was completely devoid of mesothelial cells and revealed an underlying, finely fibrillar basal lamina. The fibrosa varied in thickness and organization, both within and between the two species, but similar nervous, vascular, and connective tissue components were observed in each. The epipericardial surface was smoother, had fewer elastic fibers, and possessed more surface cells in the human tissue than in the bovine tissue. No evidence of significant tissue degeneration or remodeling was noted in either the stored patch-grafts or heart valves when compared with control bovine and human pericardial tissue layers.

Transposition of the great arteries associated with total anomalous pulmonary venous connection: a surgical approach.

The association of transposition of the great arteries with total anomalous pulmonary venous connection is very rare. In this report we describe 1 patient with this combination of anomalies who underwent successful repair. The patient has made an uneventful recovery.

Morphological alterations in dura mater encephali used as ventricular wall grafts in the canine heart.

Structural changes within homologous dura mater patch-grafts surgically implanted in the right ventricular wall of the heart were studied in nine adult dogs utilizing light microscopy and transmission and scanning electron microscopy. Physical examination of the dogs after surgery presented no clinical signs of abnormalities caused by either the surgery or the nature of the graft. After one week of implantation, a fibrous organization extending from the wound margins over the entire graft greatly increased its thickness. In addition, it was observed that (1) an increase in cellularity, vascularity and connective tissue elements occurred on the external surface of the patch-graft, (2) these same changes occurred regardless of which surface (periosteal or arachnoidal) was used as the external or pericardial surface, (3) the graft core underwent a transition from a relatively acellular and avascular connective tissue structure into one that was heavily infiltrated by a variety of cellular elements and new blood vessels, and (4) these morphological changes were interpreted as an attempt to incorporate the graft into the host tissue, resulting in an increase in both viability and stability of the graft. These findings indicate that homologous dura mater is a suitable material for use in the surgical repair of the cardiac wall.

The De Vega annuloplasty as surgical treatment for tricuspid incompetence.

Seventy-six patients with tricuspid insufficiency associated with other valvular lesions underwent De Vega annuloplasty. There were mitral lesions in 74 patients, aortic valve lesions in eight and atrial septal defects (ASD) in four. The radiographic and electrocardiographic findings and hemodynamic data are reported for 66 patients. Replacement of one or two valves was performed in 56 patients, one or two valves commissurotomy in 21 and closure of the ASD in four. The immediate postoperative mortality was 19.7%. Forty-four patients were followed from six to 59 months. There were three late deaths and clinical conditions were improved in all the survivors except one who presented mitral restenosis. Discrete residual tricuspid incompetence occurred in 11 patients (25%). We conclude that the De Vega annuloplasty is the treatment of choice for functional tricuspid incompetence.

Vascular anastomosis by argon laser beam.

Twenty-four mongrel dogs, weighing 13 to 24 kg, were used to study the effectiveness of anastomosis by Argon Laser beam. After anesthesia, intubation and controlled ventilation, they were submitted to three types of vascular anastomoses: saphenous vein intercarotid artery bypass; left mammary artery/left anterior descending coronary artery bypass; and veno-venous anastomosis. In all groups, 0.8 to 1.5 watts of Argon Laser power were applied for a total time of 90 to 300 seconds. The lower power was for veno-venous anastomoses and the greater was applied for arterial anastomoses. The mean values of resistance of the laser anastomosis to pressure-induced repture were 730 mm Hg in the immediate postoperative study, but increased to 2,500 mm Hg 30 days after surgery. No signs of occlusion were demonstrated at the anastomotic sites by the angiographic and anatomopathological studies performed.

Surgical treatment of ruptured aneurysms of the innominate artery.

The cases of 3 patients with an aneurysm of the innominate artery treated surgically are reported. The clinical manifestations were different, and the surgical procedures employed also varied. In 1 patient, the neck of the aneurysm was isolated and clamped near the aortic arch. It was closed, and a graft was interposed between the ascending aorta and the right carotid and subclavian arteries. In the second, the aneurysm was resected under cardiopulmonary bypass, deep hypothermia, and total circulatory arrest. The neck was closed with a large Teflon patch, and a tube graft was interposed between the ascending aorta and the right carotid artery. In the third, a graft was interposed between both carotid arteries; conventional cardiopulmonary bypass was instituted, and the aorta was clamped between the innominate and the left carotid arteries. The neck of the aneurysm was closed, and a graft was interposed between the ascending aorta and the right carotid and subclavian arteries. All patients had an excellent postoperative course. Our comments regarding the clinical and surgical aspects of this condition are based on the present experience and reports in the literature.

Study of the periosteal and arachnoidal aspects of dura mater implanted surgically in the ventricular wall of the canine heart.

After surgical removal of a portion of the cardiac wall, homologous dura mater cardiac grafts were sutured to the margins of the incision in the sternocostal wall of the right ventricle of the canine heart and recovered after 1, 4, 6 and 8 weeks of implantation. Representative tissue specimens were processed for and studied by means of SEM and TEM. The primary objectives were to study morphological changes in the dura mater grafts used to repair the lesions or defects in the cardiac wall and to compare alterations in the periosteal and arachnoidal aspects of the dura mater grafts after being implanted for varying periods of time. After one week of implantation, an amorphous layer of fibrin was deposited on or near the luminal surface of the original dura mater grafts. At four weeks of grafts implantation, a 'remodeling' process was apparent below the luminal surface of the graft. Although a large accumulation of fibrin was still present at this time, there was also an increase in the number of cellular and fibrillar components within the implant. Large numbers of macrophages and active fibroblasts were visible at this time along with new collagen. At the sixth week of implantation, an abundance of active fibroblasts, the presence of normal collagen and a darkly staining material interpreted as recently synthesized connective tissue components, fibrin deposits and/or degenerating collagen were also observed. Phagocytosis of the remaining fibrin was noted during this period indicating a continuation of the remodeling process at the luminal surface. Finally, after eight weeks of implantation, it was revealed that the original densely woven and relatively acellular graft had become infiltrated with various blood cells and vascular channels.