Toxicity in vital fluorescence microscopy: effect of dimethylsulfoxide, rhodamine-123, and DiI-low density lipoprotein on fibroblast growth in vitro.

Fluorescence microscopy performed on living cells is a valuable technique for elucidating patterns of cell growth in vitro over artificial biomaterials such as vascular grafts, and for in vivo studies such as identification and treatment of atherosclerotic plaques. Two fluorescent dyes of particular value for vital fluorescence studies are Rhodamine-123 and 3,3'-dioctadecylindocarbocyanine-labeled low density lipoprotein (DiI-LDL). We examined the toxicity of these two dyes and of dimethylsulfoxide (DMSO), a solvent used in Rhodamine-123 studies, on the growth of MRC5 human fetal fibroblasts in monolayer culture.

It will work: the first successful mitral valve replacement.

In 1959, a prosthetic mitral valve of flexible polyurethane with Teflon chordae tendineae was designed and fabricated. After a series of experiments in dogs carried out at the Clinic of Surgery at the National Heart Institute, on March 11, 1960, this valve was used as a total replacement of the mitral valve of a 44-year-old woman with mitral regurgitation. After an uneventful postoperative course, she was discharged from the hospital and did well thereafter, but died suddenly, presumably of an arrhythmia, 4 months after operation.

Vital fluorescent staining of human endothelial cells, fibroblasts, and monocytes: assessment of surface morphology.

Vital fluorescent staining of human endothelial cells, fibroblasts, and monocytes seeded on a variety of surfaces has been carried out to develop a method for studying cell growth and interactions on viable cells. Using special fluorochrome markers and monoclonal antibodies, it was possible to differentiate different cell types as they grew on polymer surfaces similar to ones that are presently used on artificial heart valves and vascular grafts.

Fluoroscopic technique of subclavian venous puncture for permanent pacing: a safer and easier approach.

Infraclavicular subclavian puncture may be performed with fluoroscopic observation of the needle trajectory. In 92 patients so implanted between July 1985 and May 1987 uneventful venous access was achieved in 90, one was unsuccessful and one patient had subcutaneous emphysema, a complication rate of 2.2%.

Delayed sternal closure. An improved method of dealing with complications after cardiopulmonary bypass.

Intraoperative closure of the median sternotomy after cardiac operations in patients with complications, including severe postoperative bleeding, impaired cardiac function caused by myocardial edema, and cardiac dilatation, may lead to a critical and possibly fatal deterioration of hemodynamic function. In an effort to prevent this complication, we delayed mediastinal closure in 15 patients, covering the wound temporarily with a sheet of rubber latex (Esmarch bandage). An oval patch of this material was sized and sutured to the skin edges with a continuous suture.

Pacemaker backup-mode reversion and injury during cardiac surgery.

Both electrocautery and internal defibrillation are routinely used in cardiac operations. The cases of 5 patients are presented in whom backup-mode reversion or injury of permanently implanted pulse generators occurred during a cardiac procedure. The theoretical explanations for backup-mode reversion and generator or tissue injury are discussed, and recommendations are made for the management of patients with a pacemaker who are to undergo a cardiac operation.

Observations on 100 patients with continuous intraoperative monitoring of intramyocardial pH. The adverse effects of ventricular fibrillation and reperfusion.

Intramyocardial pH and temperature data recorded in 100 patients undergoing cardiac operations were analyzed to elucidate the effects of ventricular fibrillation and reflow. All patients underwent a single period of aortic clamping. Systemic hypothermia (25 degrees C) and intermittent cold crystalloid K+ cardioplegia were employed for myocardial protection.

Implications of late morphology of Braunwald-Cutter mitral heart valve prostheses.

Interrelationships among silicone poppet wear, cloth wear, and tissue ingrowth were investigated in 14 retrieved Braunwald-Cutter heart valve prostheses following implantation of 37 to 118 (mean 83) months. Six aortic valves (mean 81 months) had severe cloth and poppet wear. In three the poppet had escaped.

First report of intramyocardial pH in man. II. Assessment of adequacy of myocardial preservation.

Intramyocardial pH and temperature were continuously measured in the anteroseptal region in 40 patients undergoing aortic cross-clamping during cardiac operations. Myocardial protection was achieved with systemic cooling (25 degrees C) and multidose potassium cardioplegia (4 degrees C). A clinical myocardial preservation score was devised based on intraoperative and postoperative need for inotropic support, postoperative creatine kinase isoenzyme (CK-MB) and electrocardiographic changes, and radionuclide ventriculography.

Considerations in the development of artificial heart valve substitutes for use in infants in small children.

Experimental studies carried out in our laboratory suggest that it is possible to develop a family of stent-supported tissue valve substitutes suitable for use in tissue and annuli of the hearts of small children in tissue annulus sizes ranging from 12 to 22 mm. Either glutaraldehyde-preserved, stent-supported primate tissue aortic valves or tissue leaflet valves constructed from dura mater preserved in 98 per cent glycerine can be used. In both instances, hemodynamics assessment of the valve substitutes in a mock circulation indicated that function was acceptable at the cardiac outputs normal for infants and children during the first few years of life.

Femorofemoral bypass graft in intra-aortic balloon counterpulsation.

Femorofemoral arterial crossover grafts were used in three patients to avoid or correct limb ischemia during intra-aortic balloon counterpulsation. In retrospec, these grafts should have been used in two earlier patients in whom the balloon was removed prematurely. They are applied to the femoral artery just distal to the site of insertion of the balloon or the the balloon access graft.

Use of the doubly tapered graft for the creation of a systemic-pulmonary arterial shunt.

It is now possible to construct vascular grafts of expanded polytetrafluoroethylene having complex configurations. In this series of experiments a double tapered graft was used to create a bypass shunt between the aorta and the pulmonary artery in rhesus monkeys and between the aorta and the iliac artery in dogs. When the synthetic material was placed under a slight degree of tension, a high degree of patency was achieved in animals killed three to six months following implantation.

Acceleration of tissue ingrowth on materials implanted in the heart.

A technique for accelerating the development of tissue layers on fabrics implanted in the bloodstream has been explored in dogs and monkeys. Endothelial cell seeding of the fabrics with cells derived from the endocardial surface of the atrium together with an autogenous plasma coating was shown to accelerate organization of fabric-covered devices implanted in the bloodstream of adult primates. At the same time, this technique appears simple and rapid enough to be practical in a clinical setting.

Local cardiac hypothermia for myocardial protection during correction of congenital heart disease.

Eighty-eight operations for correction of intracardiac congenital heart defects were performed using local cardiac hypothermia for protection of the ischemic myocardium. Twenty-six patients underwent repair of tetralogy of Fallot, 23 had patch closure of ventricular septal defect, 24 had correction of various types of congenital aortic stenosis, and 15 were operated upon for other complex lesions. The overall operative mortality was 5.