Long-term clinical experience with the Omnicarbon prosthetic valve.

BACKGROUND: From February 1985 to December 1994, 781 Omnicarbon valve prostheses were implanted in 647 patients. These were 357 male and 290 female patients with a mean age of 53.5+/-10.5 years (range, 4 to 78 years). Before operation, 81% of the patients were in New York Heart Association class III or IV, 16% were in class II, and only 3% were in class I. METHODS: There were 227 aortic valve replacements (AVR) (35%), 286 mitral valve replacements (MVR) (44%), and 134 double-valve replacements (DVR) (21%) (AVR + MVR). Follow-up was 96.3% complete and consisted of 2,746 patient-years (mean follow-up, 4.6 years, and maximum follow-up, 10.7 years). RESULTS: Hospital mortality rates were 7.0% for AVR, 8.0% for MVR, and 8.2% for DVR. The annualized rate of anticoagulant-related hemorrhage was 0.8% per patient-year, and thromboembolism occurred at a rate of 0.7% per patient-year. No structural failure was observed during 10-year follow-up. Twenty-one instances of nonstructural dysfunction (two, pannus growth, and 19, dehiscence) of the Omnicarbon valve occurred in 20 patients, an incidence of 0.8% per patient-year. Hemolytic anemia was observed only in the presence of valvular dehiscence (6 of 19). Eight patients (0.3% per patient-year) had development of prosthetic valve endocarditis (4, AVR; 2, MVR; and 2 DVR). At the end of 10 years of follow-up, 91% of the survivors were in New York Heart Association class I or II. The overall survival rate at 10 years was 82.5%+/-2.6% (85.0%+/-3.9%, AVR; 81.0%+/-4.1%, MVR; and 82.5%+/-2.6%, DVR). Considering only valve-related deaths, the survival rate at 10 years was 91.9%+/-2.4% (90.0%+/-2.7%, AVR; 93.1%+/-3.8%, MVR; and 90.0%+/-1.8%, DVR). CONCLUSIONS: Clinical results over a 10-year follow-up are excellent with the Omnicarbon prosthesis.

Late cardiac tamponade after open heart surgery.

Delayed cardiac tamponade after open heart surgery is relatively uncommon, but constitutes a life-threatening condition that must be diagnosed and managed promptly. We report 21 patients who developed cardiac tamponade 5 to 53 days after open heart operations. Possible etiological factors included anticoagulant therapy (19 patients), excessive mediastinal drainage in the postoperative period (10 patients), postpericardiotomy syndrome (4 patients), and coagulation disorders (1 patient). The clinical presentation was insidious and the diagnosis was often difficult to establish at the outset. A high index of clinical suspicion and echocardiography were the most reliable means to reach an early diagnosis. Twenty patients in whom delayed tamponade was suspected were operated and all of them survived. In one patient tamponade was not diagnosed antemortem and he died; on autopsy left heart compression by a large loculated clot was found. Decompression of the pericardial space can be accomplished by pericardiocentesis or by surgical means (subxiphoid pericardiotomy, median sternotomy, or thoracotomy). Although pericardiocentesis alone may be effective, mainly when the postpericardiotomy syndrome is the suspected etiology, we recommend open procedures since the presence of blood clots and adhesions has been a frequent finding.

Mitral valve replacement and splenectomy in a patient with chronic idiopathic thrombocytopenic purpura.

We report the management of a patient with chronic idiopathic thrombocytopenic purpura and mitral valve disease. Although a two-stage approach was planned (splenectomy followed by mitral valve replacement one month later), the patient developed medically-resistant heart failure, and splenectomy plus mitral valve replacement were performed during the same operation. The platelet count at operation was 20,000/mm3. Platelet transfusion, used at the end of cardiopulmonary bypass, was considered no longer necessary in the postoperative period, as the platelet count quickly increased after the first postoperative day. The postoperative course was uneventful. Though we believe the two-stage surgical approach is preferable, our case shows that open-heart operations and splenectomy can be successfully performed simultaneously in patients with idiopathic thrombocytopenic purpura.

[Experimental cardiogenic shock (author's transl)]. / Shock cardiogénico experimental.

An experimental model fo cardiogenic shock has been developed in anesthetized dogs. The shock was produced by injecting mercury into the second diagonal branch of the descending anterior coronary artery. Arterial and venous pressure E.C.G., aortic, renal and circumflex flow were directly measured. Other parameters such as O2 consumption and arterio-venous difference were also studied. The present model seems very useful to make therapeutic studies. Open chest surgery has been used for simplicity and economic reasons.

Isolated mitral valve replacement with the Björk-Shiley prosthesis in 100 consecutive patients. Short- and long-term results.

Single mitral valve replacement with the Björk-Shiley tilting disc prosthesis was performed in 100 consecutive patients between March 1971 and December 1973. The hospital mortality was 13% and the late mortality was 6%. 74 of the patients were followed for periods ranging between 12 and 46 months (mean follow-up: 24 months): clinical improvement was noted in 92%. The incidence of postoperative embolism, including 1 case of prosthesis thrombosis, was 6.7%, and all cases occurred within the first 9 months after surgery. 6 patients required reoperation because of prosthesis dysfunction due to thrombosis (1 patient), leakage (3), and late disc entrapment (2).

Coarctation of the aorta and severe aortic insufficiency: What to repair first?

A new surgical approach is proposed for patients with coarctation of the aorta associated with severe aortic valvular insufficiency. The valvular lesion should be repaired first and the coarctation corrected during a second operation; both interventions should be done during the same hospital stay. We base our approach on the belief that improved coronary perfusion can be achieved when the aortic insufficiency is corrected first. The disadvantages of the opposite surgical approach, such as anticoagulation problems, renal underperfusion, and hypertensive complications are easily avoided.

Perforation of the right ventricle and cardiac tamponade caused by a venous catheter.

A case is reported in which a venous catheter perforated the right ventricle and caused cardiac tamponade. Methods recommended to avoid such complications include limiting the length of the radio-opaque catheter, and modifications to the catheter tip.

[Osmolar and free water clearance as renal function test during extracorporeal circulation with parcial and total hemodilution (author's transl)]. / Aclaramiento osmolar y de agua libre como prueba de función renal durante la circulación extracorpórea con hemodilución parcial y total

Four groups of dogs are subjected to extracorporeal circulation. Total hemodilution is used in groups I and II, either in normothermia or moderate hypothermia at 30 degrees C. Partial hemodilution is used in groups III and IV with identical temperature variations. The animals are kept under extracorporeal circulation for 120 min. Osmolar and free water clearance are measured at basal conditions after 40, 80 and 120 min. The present results show that total hemodilution should be used in those patients subjected to extracorporeal circulation where renal function has been previously disturbed.

Reoperation for dysfunction of the Björk-Shiley mitral disc prosthesis: report of eight cases.

Of 193 patients with Björk-Shiley mitral valve prostheses, replacement was necessary in 8 (4.1%). The reasons for reoperation were: detachment (4), thrombosis (1), technical error (1), and late disc entrapment (2). Five of these patients died (62.5%), the death being directly related to the need for urgent operation because of low cardiac output. We recommend avoiding the use of the larger sized Björk-Shiley prostheses, since striking of the disc against the ventricle wall, probably consequent to postoperative decrease in heart size, may appear even 1 year after implantation of the prosthesis. An early diagnosis and early reoperation offer these patients a much more favorable prognosis.

Prosthetic valve endocarditis by opportunistic pathogens.

The incidence of endocarditis produced by the so-called "opportunists" as a complication of prosthetic valve surgery is progressively increasing in frequency and gradually transforming the clinical picture habitually associated with this disease. We report six cases of endocarditis produced by opportunistic microorganisms (two cases by Candida, and the remaining by Serratia, Actinobacillus, Acinetobacter calcoaceticus, and Bacteroides fragilis, and by Corynebacterium diphtheriae) in four male and two female patients, making special comment on our findings, diagnostic criteria, and treatment. The patients' ages ranged from 9 to 54 years, and all six patients had long-term complications, with symptoms appearing between 45 days and four years after prosthetic valve surgery. The progressive increase of this new type of prosthesis infection is favored by the indiscriminate use of certain drugs and especially by the prophylactic use of antibiotics.

Cardiac valve replacement with the Björk-Shiley prosthesis in young patients.

Between 1971 and 1974, 26 valve replacements with the Björk-Shiley tilting disc valve prosthesis were performed in 23 children between 4 and 16 years of age. Mitral valve replacement was carried out in 11 patients, aortic valve replacement in 9 and double replacement in the other 3 patients. Several of the patients presented associated lesions which were also corrected at the same intervention, One patient died during the postoperative period; the remaining 22 all showed significant clinical remission. No incidents of thromboembolism or complications of any other nature were observed during follow-up periods of 6 to 26 months. It is our belief that the Björk-Shiley valve represents an improvement over other prostheses currently used for the surgical correction of valve disease in children.