Experience with the Mitroflow aortic bioprosthesis.

From October 1985 to May 1990, the Mitroflow bovine pericardial valve was placed in the aortic position in 168 patients (97 men, 71 women) with a mean age of 69.7 years. Eighty-nine patients had isolated aortic valve replacement, and 79 had aortic valve replacement and additional procedures. Follow-up over 7 1/2 years includes 781 patient years (426 for isolated aortic valve replacement). Mean follow-up time is 56 months. Peak-to-peak gradients (in millimeters of mercury) measured in the intraoperative period averaged 11.0 +/- 8.7, 11.8 +/- 10.8, and 8.6 +/- 8.2 for 19 mm, 21 mm, and 23 mm valves, respectively. Hospital mortality was 7.3% (14 patients); all deaths were non-valve related. Late mortality of 20.1% in 31 patients resulted from cardiac failure (n = 8), sepsis (n = 4), valve reoperation (n = 1), non-cardiac causes (n = 15) and sudden, unknown causes (n = 3). Fifteen thromboembolic episodes occurred, but only three late thromboembolic episodes occurred in isolated aortic valve replacement without other risk factors. Four early and four late episodes of endocarditis occurred. Seven patients had clinical valve dysfunction, and five others required reoperation for structural deterioration, with one death. At 94 months, overall survival was 64% +/- 5%. Freedom from thromboembolic episode was 87% +/- 3% and 90% +/- 4% for isolated aortic valve replacement. Freedom from combined reoperation or clinical dysfunction was 75% +/- 8%: 64% +/- 15% for those under 70 years of age, and 87% +/- 7% for those 70 years of age and older. The valve has favorable hemodynamics. Durability begins to decline during the sixth year after implantation, possibly at a slower rate in patients older than 70 years of age.

Primary cardiac tumors. Diagnosis and management in 14 cases.

In our experience over a 10-year period at Westchester County Medical Center (Valhalla, NY), we diagnosed 11 left atrial myxomas and three primary cardiac malignancies in ten females and four males, aged 18-74 years. Two-dimensional echocardiography enabled the correct diagnosis of these lesions. Detailed characteristics of the cardiac tumors were provided by magnetic resonance imaging (MRI) scanning in five patients. Two of three malignancies were only biopsied; the myxomas were completely excised. We emphasized removal of tumor and its attachments to the atrial wall, accomplished by left or biatrial incision, full-thickness excision of the area of attachment, and pericardial patch closure of the atrial or free-wall defects. Associated procedures included mitral valve repair (three) and coronary artery bypass grafting (two). There was no mortality associated with the surgery. Two patients with malignancy died three and 36 months after surgery; a third is alive at 30 months after surgery. No patients with myxoma has had recurrence from 16 to 100 months. Preoperative diagnosis of cardiac tumors is enhanced by MRI scanning and may help in planning the surgical procedure. Complete and timely removal of these tumors contributes to long-standing patient survival.

Simplified method for reoperation on the mitral valve.

Reoperation on the mitral valve is becoming more common because of the degeneration of bioprosthetic valves, endocarditis, and malfunction or thrombosis of mechanical valves. We advocate a technique that transforms a technically difficult operation into one that is much less tedious, time-consuming, and dangerous than reopening a sternal-split operative site the second, third, or fourth time. Favorable experience in 11 patients using right anterolateral thoracotomy without aortic or right atrial cannulation and without aortic cross-clamping or cardioplegia is presented.

Coronary revascularization in young patients.

From 1978 to 1982, 92 of our 1704 patients undergoing coronary bypass surgery were 40 years of age or younger. Eighty-six were male and six were female. The main indications for surgery were refractory angina and unstable angina. A family history of heart disease, smoking, and hypertension were major risk factors. The majority of patients had triple vessel disease, and six had left main lesions. Left ventricular function was moderately or severely impaired in 24. Coronary revascularization was performed with internal mammary and saphenous vein conduits, with a mean of 3.7 grafts per patient (range, 1 to 7). There was no operative mortality, but one patient required an intraaortic balloon pump. Perioperative infarction determined by Q waves occurred in one patient, while eight had enzymatic evidence of infarction. Late follow-up to 60 months showed three late deaths of cardiac origin. Eighty-three survivors were greatly improved, and 50 were asymptomatic. Sixty-five patients returned to work. Seventy percent of smokers stopped smoking; half the patients exercised regularly, and half maintained dietary modifications. Coronary bypass grafting is an effective rehabilitation procedure in the young. Long-term attention to risk factors and life style is required to maintain a beneficial outcome.

Delayed sternal closure as a safe adjunct to support biventricular failure after open heart surgery.

Over a four-year period, 22 patients of 2495 undergoing open heart surgery sustained severe biventricular failure (BVF) and would not tolerate primary sternal closure. Reasons for BVF included intraoperative injury, perioperative infarction, global dysfunction, cardiopulmonary edema, and intractable arrhythmia. Mechanical assist devices were required in nine patients. Average cardiac index fell to 1.1 L/min/m2 with attempts to close the chest, then stabilized at 1.9 with the sternum open and only soft tissue closed. After 3 to 11 days, cardiac index rose to 2.5 when assist devices were removed, inotropic agents decreased, and the sternum closed. Three early deaths (5-12 days) were caused by progressive biventricular failure. Five later deaths (19-64 days) were associated with renal and respiratory failure, superinfection, and sepsis. All of these required tracheostomy. Survival of 14 patients was not related to early low cardiac output, preoperative status, timing of sternal closure, or age, but was associated with early recovery of respiratory function without need for tracheostomy, avoidance of renal failure, and satisfactory alimentation. Sternal infection occurred in three patients, resulting in one death. The hospital stay ranged from 12 to 230 days. There was one death resulting from respiratory failure 14 months postoperatively. Our findings show that delayed sternal closure lessens early cardiac instability during BVF, helps allow recovery, and does not produce long-term disability.

Hemodynamic comparison of albumin and hydroxyethyl starch in postoperative cardiac surgery patients.

The hemodynamic effects of 2 plasma volume expanders were compared in postoperative open heart surgery patients. Albumin 5% (A) or hydroxyethyl starch 6% (HES) solutions were infused according to indications based on cardiac index (CI) and pulmonary wedge pressure (WP), and their effects evaluated by physiologic profile measurements. Both groups demonstrated significant increases with volume infusion in CI (A from 2.37 to 2.84; HES from 1.97 to 2.49 L/min X m2) and WP (A from 9.4 to 13.7 mm Hg; HES from 11.9 to 13.2 mm Hg). Stroke index and stroke work increased similarly. Mean systemic arterial pressure (MAP) and mean pulmonary arterial pressure (MPAP) remained unchanged. No significant difference for any variable was demonstrated between the A and HES groups. In the volume used, from 250 to 750 ml, HES caused no bleeding abnormalities. HES is as effective as A as a plasma volume expander in postoperative cardiac surgery patients.

Paraplegia associated with intraaortic balloon pump counterpulsation.

Two patients developed paraplegia associated with the use of the intraaortic balloon pump. In one patient, transient spinal ischemic episodes ceased after removal of the intraaortic balloon and the second patient apparently sustained spinal cord infarction. Possible etiologic mechanisms include vascular occlusion due to balloon position, arterial spasm, thromboembolic phenomena, hypotension, hypoxia and arterial dissection.

Results of combined valvular and myocardial revascularization operations.

A total of 105 patients underwent combined coronary artery and valvular operations. Sixty-six had combined coronary artery bypass grafting (CABG) and aortic valve replacement (AV), 28 had CABG and mitral valve operations (MV), and 11 patients had CABG and double or triple valve operations (DTV). An average of 3.0 bypasses was done, range one to seven. These patients were compared to a similar group of patients who underwent valve replacement(s) only, without CABG. Bypass time was increased for the combined groups, as was ischemic cross-clamp time. Early mortality was 3.0% AV, 3.5% MV, and 9.1% DTV in the combined groups and 1% in the valve only groups. The higher mortality for the combined groups was almost entirely due to the 23% mortality in women over 70 years of age. Perioperative myocardial infarction (MI) was higher in the combined groups (5% MI, 9% probable MI versus 2.9% MI, 4.1% probable MI). All survivors were in improved clinical condition and free of angina. Mortality and improvement were unrelated to perioperative infarction. The small increase in risk compared to the significant improvement from the combined approach has led to the following principles: coronary arteriography on all adult patients requiring valvular operations; bypass of all significant coronary lesions; restoration of valvular function and hemodynamics; and myocardial preservation with cold cardioplegia during a single period of cross clamping, topical cold, and systemic hypothermia.

Durability of measured mitral annuloplasty: seventeen-year study.

This report describes the technique and results of measured mitral annuloplasty performed in 196 patients having isolated mitral valve disease during the 17 years between January, 1961, and January, 1978. These patients represent 35% of all of those operated upon for isolated mitral valve disease during this period. Ages ranged from 3 to 70 years. Annuloplasty was performed in 115 patients and both commissurotomy and annuloplasty in another 81 patients. The operative mortality rate was 4.5% and the late mortality rate 8.7%. There were six arterial embolic episodes during the 17 years. Reoperation was required in 8% with another repair of the valve being possible in one third of them. This study suggests that measured repair of mitral regurgitation resulted in lower operative mortality, late mortality, and incidence of embolization when contrasted with mitral valve replacement. This operation appears to be the preferred procedure for certain subsets of patients (1) who require operation during infancy or childhood, including during active carditis; (2) who require operation during the childbearing age; and (3) in whom anticoagulation poses a severe threat to life or quality of life.

Increased cardiac output by downstream pumping with a reversed unidirectional intra-aortic balloon.

Downstream and upstream pumping with unidirectional intra-aortic balloons was compared in 8 open-chest normal mongrel dogs anesthetized with pentobarbital. Downstream pumping effect a 32 per cent increase in cardiac index, a 24 per cent decrease in systemic resistance, and a 2 per cent decrease in heart rate. Upstream pumping did not significantly affect these parameters. Mean aorta pressure proximal and distal to the balloon was not altered significantly by pumping in either direction. This unique observation of increased cardiac output may have important implications for the treatment of low output cardiac failure. Preliminary studies including baroreceptor denervation suggest that a reflex mechanism may be involved.

Open-heart experience in infants using normothermia and deep hypothermia.

During the 9-year period from 1967 through 1975, 124 open-heart operations were performed on infants less than 1 year of age with 35 operative deaths (28%). Ninety-seven of these procedures used continuous cardiopulmonary bypass with normothermia or mild hypothermia, and 27 were done under deep hypothermia and circulatory arrest. Mortality and morbidity were similar regardless of the operative technique, although deep hypothermia facilitated the repair of complex lesions. The highest mortality occurred in infants less than 3 months of age. Respiratory insufficiency, usually requiring prolonged ventilatory support, occurred only among infants who had pulmonary overcirculation or congestion prior to operation. Adequacy of intraoperative repair and postoperative care were the major determinants of survival.

Hemodynamic alterations with a reversed unidirectional intra-aortic balloon.

The hemodynamic effects of dual-chambered unidirectional balloon pumping in alternate directions were studied in 44 trials conducted on 8 dogs. Results indicate an increase in cardiac output in normal dogs with downstream pumping by unidirectional intra-aortic balloon, which may have important implications for the treatment of low output cardiac failure.