Results of replacement of cardiac valves by homologous dura mater valves.

Homologous dura mater valve was employed in a series of 533 patients in the period between January 1971 and May 1974. The dura mater was sterilized and preserved in 98 percent glycerol solution at room temperature. Important data were the following (1) no significant pressure gradient through the vale at rest; (2) no bacterial endocarditis; (3) two cases of fungal endocarditis; (4) no degeneration or retraction of the leaflets; (5) no thrombus formation in the valve; and (6) no anticoagulants were used in this series.

Surgical treatment of Ebstein's anomaly. Early and late results in twenty patients subjected to valve replacement.

Twenty patients with Ebstein's anomaly underwent corrective operations between 1965 and 1978. Sixteen were in Functional Class III or IV (N.Y.H.A.) and four were in Class II but were having episodes of anoxia, syncope, or a rapid increase in cardiac size. In the first 10 cases (1965 to 1972) the tricuspid valve was replaced with a Starr-Edwards prosthesis, and in the second group (1972 to 1978) a dura mater valve was used. Five patients also underwent plication of a very large atrialized right ventricular segment. The atrial septal defect was closed totally in four cases, partially in eleven cases, and left open in five cases; one patient also underwent closure of the ventricular septal defect. Four patients died in the immediate postoperative period, three of whom were in the first group. There were three late postoperative deaths in the remaining 16 patients, all of them in the first group. All 13 of the surviving patients are in Functional Class I, except for one patient who is in Class II.

Variable-column bubble oxygenator. A new system for bubble oxygenation.

A new bubble oxygenator has been developed. Its main advantage is that the dimensions of the oxygenating chamber can be varied. Thus, the capacity for oxygenation may be adapted to different patients. It was used in 2,700 open-heart operations performed at the Institut do Coracão, Faculdade de Medicina, Universidade de São Paulo, between January, 1971, and December, 1973. A group of 50 patients were subjected to more detailed studies. We found that the average hemolysis was 38.67 mg. per cent with a mean perfusion duration of 69 minutes, 38 seconds. Fibrinogen and platelet concentrations decreased by 14 and 25 per cent, respectively. The pH, PcO2, PO2, and base excess before and after cardiopulmonary bypass ranged within normal levels, and oxygenation (PO2) was always satisfactory.

Homologous dura mater cardiac valves. Structural aspects of eight implanted valves.

We studied eight homologous dura mater valves removed 1 to 35 months after implantation. Five dura mater valves were placed in the mitral position and three in the aortic position. Two of the valves were obtained after deaths not related to the valve itself and six after reoperations due to immediate or late incompetence. In 2 cases the dura mater valves were entirely normal, both macroscopically and microscopically. In 2 other cases the leaflets were caught by stitches related to the struts, a technical error that caused laceration of the leaflets. Not withstanding this fact, the dura mater was normal on histologic examination. In 3 cases, and probably in 1 other, one or two leaflets were detached partially from the suture line, probably because of a technical error in the manufacture of the valve. These studies demonstrated satisfactory evolution of the homologous dura mater valves until 35 months after implantation. No signs of rejection or degeneration of the dura mater were observed in the present series.

Intrapulmonary balloon for temporary relief of pulmonary hypertension.

In this report, we shall describe a case of interventricular septal defect with severe cardiac and respiratory insufficiency unresponsive to clinical treatment. The critical condition of the patient prompted us to introduce an obstructive balloon into the pulmonary artery with the objective of reducing pulmonary flow and improving respiratory insufficiency. The mean pressure was reduced from 45 to 19 mm. Hg, and the infant's cardiopulmonary status improved dramatically. After 36 hours, during which the clinical picture stabilized, a banding operation was performed with success.

Congenital tricuspid stenosis treated by a palliative open operation. Report of a case.

The case is presented of a patient with congenital tricuspid stenosis who was treated successfully by a palliative open operation. The preoperative diagnosis was tricuspid atresia. At operation, however, congenital tricuspid stenosis was detected and managed by commissurotomy.. The postoperative course was very good. Later, the associated ventricular septal defect (VSD), pulmonary annular stenosis, and probably the atrial septal defect (ASD) will be corrected. We emphasize the importance of diagnosing congenital tricuspid stenosis correctly, because of the possibility of operating upon the valve itself.

Evidence of remodeling in dura mater cardiac valves.

Subcellular changes in 12 dura mater cardiac valves (in the mitral or aortic position) surgically removed after 23 to 108 months of implantation owing to calcification, rupture, or endocarditis show signs of a remodeling process. Significant morphologic changes in the connective tissue fiber matrices and cell populations were noted in the recovered valvular leaflets. Macrophages were found within electronlucent (cleared-out) areas, and they seemed to play an essential role in the remodeling process by ingesting and digesting selected connective tissue components. Fibroblasts found within these "rebuilding" areas in the dura mater tissue possessed small cytoplasmic vesicles (65 nm in diameter) being extruded from the cell. Evidence of early collagen formation was also found in association with both peripheral filaments and peripheral condensations, as well as within the connective tissue matrices surrounding the cellular elements, where electron dense amorphous material was observed. In conclusion, the long-term durability of dura mater bioprosthetic cardiac valves may be directly related to (1) glycerin stabilization and preservation of the collagen fibers, (2) the viability of the fibroblasts and macrophages within the implanted valves, and (3) the unique morphology and fine structure of the double-layered dura mater encephali. We hypothesize that the fibroblasts or myofibroblast-like cells found within the implanted leaflets, no matter what their origin, are capable of giving form and organization to the early developing connective tissue.

Homologous dura mater cardiac valves. Study of 533 surgical cases.

A group of 533 patients had cardiac valves replaced with homologous dura mater valves. The dura mater was preserved in a solution of 98 per cent glycerol and antibiotics for a period of 12 days before used. The leaflets were mounted in a stainless steel ring covered by Dacron velour. Two hundred forty-five patients had mitral valve replacement; 205 patients, aortic valve replacement; 17 patients, tricuspid valve replacement; and 2 patients, pulmonary valve replacement. Sixty-four patients were subjected to multivalvular replacements. The patients were followed for a period of 1 to 40 months after surgery with satisfactory clinical and hemodynamic results. Because 2 patients developed endocarditis produced by fungii, fungicidal drugs were added to the preservative solution. No bacterial endocarditis has been observed. No pressure gradient through the valve has been noted at rest. Anticoagulant drugs have not been used in the postoperative period.

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.

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.

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.

Four years experience with dura mater cardiac valves.

The clinical use of homologous dura mater cardiac valves was begun in January 1971. Between January 1971 and May 1975, 751 patients received 849 dura mater valves: 428 mitral, 365 aortic, 52 tricuspid and 4 pulmonary. The hospital mortality observed in this series was 13.6% and late mortality was 2.5%. The main causes of death were low-output syndrome in the immediate post-operative period or cardiac failure in the late post-operative period, due to myocardial impairment. Paravalvular leaks and errors in the manufacture of the valve were the main causes of regurgitation both in the immediate and late post-operative period. The incidence of thromboembolism, bacterial and fungal endocarditis was: 0.79%, 0.39%, 0.53% respectively. The results obtained with dura mater valve in a period of four years are satisfactory from the clinical and hemodynamic points of view.

Long-term results of mammary artery implants.

Eighty out of eighty-six patients (93%) with mammary artery implants were followed postoperatively for an average of three and a half years. The immediate mortality rate was 7% (6 cases), and the late mortality was 6% (5 cases). All had angina preoperatively. Twenty-four had a history of myocardial infarction and thirty-one were on limited physical activity, because of the pain. After surgery, thirty-three (45%) became asymptomatic. The angina improved significantly in thirty-five (47%) and remained unchanged in six (8%). Improvement in ventricular repolarization on ECG was observed in 69% of the patients. Postoperative cineangiography was performed in twenty-three patients; thirteen with single and ten with double implants. Out of the total of thirty-three implants, four (12%) were obstructed and twenty-seven patent (82%); twenty were in two cases of double implant, only one implant could be satisfactorily studied effectively functioning (61%). No obstructions were seen in the single implants. Non functioning implants were found in five (38%) of the thirteen single implants and in two of the twenty double ones (10%). The highest incidence of obstruction or non-functioning implants occurred in the group that did not show improvement (43%). This rate fell to 40% in the group that had some improvement and to 29% in those that were completely asymptomatic. Twelve of the eighteen patent mammary implants (67%) on the anterior wall of the left ventricle and eight of nine (89%) on the lateroinferior wall, established collateral circulation to the coronaries. Indication for surgery was considered satisfactory for nineteen out of the twenty-three patients and poor in four. There were two cases of obstruction of the implant (7%) in the group where surgery was correctly indicated and three of the twenty-three (11%) patent implants were non-functioning. Clinical improvement of the angina occurred in 84% in the first group and 50% in the other. In conclusion, this technique of indirect revascularization of the myocardium is valid for patients with severe diffuse lesions of the coronaries with a collateral network and preserved myocardial contractility.

Anomalous origin of the left coronary artery from the pulmonary artery. Surgical repair of an unusual form.

The authors present a case of a 24-year-old woman with anomalous left coronary artery originating from the pulmonary artery. Surgical correction was performed by the direct transposition of the anomalous left coronary artery from the pulmonary artery to the ascending aorta, without interposed graft. Pre- and postoperative evaluations, including angiograms and cycloergometer stress test are presented. The advantages of this technique are discussed, emphasizing the creation of a two-coronary system without the use of prosthetic, arterial or venous grafts. In the present case the left coronary artery originated from the right posterior sinus of the pulmonary artery. The patient is doing well 23 months after operation.

Direct myocardial revascularization in young patients: analysis of 100 consecutive cases without operative mortality.

The authors studied a series of 100 patients submitted to direct myocardial revascularization before 40 years of age. One hundred and seventy-three saphenous vein by-passes and 4 mammary artery left descending coronary artery anastomoses were performed. There was no operative mortality and the late mortality was 2%. The period of postoperative clinical evaluation of the patients varied from 12 to 60 months (mean 32.0 months).

Surgical treatment of the congenital fistulae of coronary arteries.

Six cases of coronary artery fistulae surgically treated are presented. All patient but one was male; the ages varied from 4 to 44 years. The fistulae originated from the left coronary artery in three cases from the right in two cases and from both arteries in one case. The draining heart chambers were the right atrium in three, the right ventricle in two and the pulmonary artery in one case. Associated lesions were present in three cases. One patient died on the early postoperative period and the evolution was satisfactory in five cases.

Late results of replacement of cardiac valves by dura-mater allografts.

Homologous dura-mater valve was employed in a series of 2.338 patients in the period between January 1971 and January 1979. A restricted group of the first 272 patients were followed-up from six to eight years. This study showed gratifying results following mitral and tricuspid valves replacement and not as satisfactory results after aortic replacement. The postoperative complications were, for mitral valve: fungal endocarditis (0.68%), bacterial endocarditis (2.56%) thromboembolism (1.36%) valve dysfunction (12.9%) and reoperation was performed in 5.12% of the cases. For aortic valve replacement there was fungal endocarditis in 1.36% of cases, bacterial endocarditis in 5.68%, valve dysfunction in 29.54% and the incidence of reoperation was 23.28%. No anticoagulants were employed in this series.

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.

Homologous dura mater used to close thoracic wall and diaphragmatic defects.

We have reported the successful use of homologous dura mater preserved in glycerin at room temperature to repair large defects of the thoracic wall or diaphragm in five patients. The surgical technic involved the use of autologous bone grafts in order to stabilize the thoracic cage in one case, but in the other four the dural blade was sufficient. The postoperative course was uneventful regarding the structure and function of the dural implant in each case.

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.