CLINICAL TRIALS OF THE ABDOMINAL LEFT VENTRICULAR ASSIST DEVICE (ALVAD): PROGRESS REPORT.

An abdominal left ventricular assist device (ALVAD) is undergoing controlled clinical trials in our institution. The ALVAD is pneumatically-actuated, synchronously or asynchronously with an external console and is interposed between the apex of the left ventricle and the infrarenal abdominal aorta. It is an order of magnitude more effective than conventional intraaortic balloon pumping.

RIGHT AND LEFT VENTRICULAR HEMODYNAMIC INDICES AS PREDICTORS OF THE NEED FOR AND OUTCOME OF POST-CARDIOTOMY MECHANICAL INTRAAORTIC BALLOON PUMP SUPPORT.

Preoperative cardiac catheterization data of 21 patients requiring intraaortic balloon pumping (IABP) for weaning from cardiopulmonary bypass were analyzed and compared with similar data in 28 patients who underwent nearly similar operative procedures, but did not require IABP for weaning. Cardiac index (CI) and systemic vascular resistance (SVR) were found to have predictive value for the need of IABP for weaning from cardiopulmonary bypass and differentiated survival from non-survival. Left ventricular end diastolic pressure (LVEDP) was not found to be predictive.

COMBINED REPLACEMENT OF THE AORTIC VALVE AND ASCENDING AORTA IN JEHOVAH'S WITNESSES: REPORT OF TWO CASES.

Two Jehovah's Witnesses with large ascending thoracic aortic aneurysms and aortic insufficiency secondary to annuloaortic ectasia underwent successful combined replacement of the aortic valve and the ascending aorta. One patient received a composite graft containing an aortic valve prosthesis, which necessitated supravalvular coronary ostia reimplantation; the other patient underwent separate aortic valve and left supracoronary ascending aneurysm replacement, with reimplantation of the right coronary ostium into the graft. No blood or blood derivatives were administered.

SEQUENTIAL ELECTROCARDIOGRAPHIC ANALYSIS OF STONE HEART SYNDROME IN A PATIENT SUPPORTED SIX DAYS WITH AN ABDOMINAL LEFT VENTRICULAR ASSIST DEVICE (ALVAD).

A 21-year-old male patient underwent aortic and mitral valve replacement for progressive cardiac failure due to acute bacterial endocarditis. Ischemic myocardial contracture developed during attempts to restore cardiac activity following hypothermic, ischemic, cardioplegic arrest. An abdominal left ventricular assist device (ALVAD) was implanted and supported the circulation for nearly six days prior to cardiac transplantation.

ULTRASTRUCTURAL ANALYSES OF BLOOD-INTERFACING LININGS FORMED WITHIN PARTIAL ARTIFICIAL HEARTS OR ABDOMINAL LEFT VENTRICULAR ASSIST DEVICES: A QUALITATIVE SCHEME FOR HUMAN PSEUDONEOINTIMAL ACCRETION KINETICS.

Following each of 21 clinical trials with the partial artificial heart or abdominal left ventricular assist device (ALVAD), we have examined the blood-interfacing human pseudoneointimal (PNI) linings formed on the fibril-flocked pumping surface by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The salient results of these ultrastructural analyses can be summarized: (1) early PNI accretion kinetics (< 24 hrs) involve plasma protein adsorption, entrapment of erythrocytes, platelets, lymphocytes, numerous neutrophils and macrophages, and the deposition of fibrin within fibril flock interstices (TEM); (2) the surface (< 24 hrs) consists of interconnected fibrin strands (SEM); (3) later PNI accretion kinetics (1-6 days) involve the formation of alternating cellular and fibrin layers (TEM); (4) the surface (1-6 days) consists of cellular aggregates (inter-membrane distances of 340 A) simulating an endothelial interface (SEM, TEM). Based on these analyses, a plausible sequence of events for human PNI accretion kinetics can be advanced, i.

OBLITERATIVE RESTRICTIVE ENDOMYOCARDIAL FIBROSIS: A SURGICAL APPROACH.

Restrictive cardiomyopathies have been variously classified and interpreted. Although their etiologic and anatomic features may vary, their common denominator is indicated by restrictive hemodynamic behavior of either the left or right ventricle or both. This report describes a case in which such restriction was caused by obliterative endomyocardial fibrosis of unknown etiology.

PREFABRICATION DESIGN CONSIDERATIONS FOR A LONG-TERM ELECTRICALLY-ACTUATED ABDOMINAL LEFT VENTRICULAR ASSIST DEVICE (E-TYPE ALVAD).

The conceptual design and development of a long-term, low-profile intracorporeal left ventricular assist device is a multifaceted project involving a series of technical, anatomic and physiologic considerations. Patients with severe left ventricular failure refractory to all other forms of therapy could benefit from such a device. Prior to fabrication of such a blood pump, consideration must be given to physiologic parameters of the projected patient population.

ARRHYTHMIA WITH MITRAL VALVE PROLAPSE: RESULTS OF ANNULOPLASTY IN TWO PATIENTS.

The effectiveness of posterior annuloplasty in two patients who failed to respond to medical treatment for atrial and ventricular arrhythmias related to mitral valve prolapse (MVP) is reported. Although the etiology of arrhythmia in MVP remains mostly speculative, anatomic correction of prolapse or billowing of the mitral leaflets appears to reverse the anatomic and pathologic conditions that cause the arrhythmia.

MACROSCOPIC, MICROSCOPIC, AND MECHANICAL ANALYSES OF PROTOTYPE DOUBLE VELOUR VASCULAR GRAFTS.

In-vivo and ex-vivo evaluations of two prototype double velour tube grafts have been conducted. The experimental grafts were fabricated from terry cloth derivatives of the Dacron polyester material that is used in the construction of presently available Microvel(R) Double Velour and Cooley Double Velour Guideline(R) grafts.(*) The use of terry cloth derivatives in the experimental grafts provides a velour pile that is more uniform in height and density than current clinical grafts.

COMBINED CORRECTION OF TETRALOGY OF FALLOT AND CORONARY ARTERY OCCLUSIVE DISEASE: CASE REPORT.

A 49-year-old patient with known tetralogy of Fallot for which an aortopulmonary anastomosis (Pott's shunt) had been performed 23 years previously, underwent simultaneous myocardial revascularization for severe coronary occlusive disease and total correction of his congenital anomaly. The operation and postoperative course were uneventful, and he made a full recovery.

SILENT MYOCARDIAL INFARCTION WITH POSTERIOR INFERIOR PSEUDOANEURYSM OF THE LEFT VENTRICLE PRESENTING AS A POSTERIOR LUNG MASS.

An asymptomatic 62-year-old man developed a density in his left lower hemithorax in the retrocardiac position on chest roentgenogram, which was discovered during a routine evaluation. This was diagnosed in another hospital as a lung tumor, for which he underwent an exploratory left thoracotomy. This case points out the difficulty in the diagnosis of retrocardiac masses and suggests that echocardiography and cardiac angiography should be accomplished before attempting needle aspiration or an open lung biopsy.

SUCCESSFUL AORTOCORONARY BYPASS SURGERY IN A PATIENT WITH CLASSICAL HEMOPHILIA A.

A patient with documented Factor VIII deficiency (classical Hemophilia A) and a history of previous severe intra- and postoperative hemorrhage and transfusion reaction underwent myocardial revascularization for advanced triple vessel coronary artery occlusive disease. The coagulation status was investigated, and a replacement regimen was instituted. The surgical procedure and postoperative course were uneventful.

THEORETICAL DESIGN CONSIDERATIONS AND PHYSIOLOGIC PERFORMANCE CRITERIA FOR AN IMPROVED INTRACORPOREAL (ABDOMINAL) ELECTRICALLY ACTUATED LONG-TERM LEFT VENTRICULAR ASSIST DEVICE ("E-TYPE" ALVAD) OR PARTIAL ARTIFICIAL HEART.

Our laboratories are engaged in the design of a clinically-oriented electrically actuated long-term intracorporeal (abdominal) left ventricular assist device ("E-type" ALVAD) or partial artificial heart. This infradiaphragmatic blood pump is designed to be powered by implantable electrical to mechanical energy converter systems. THE FOLLOWING ANALYSES WERE UNDERTAKEN TO: [List: see text] The proposed "E-type" ALVAD should be capable of pumping 4-7 liters per minute at heart rates of 75-100 beats per minute during rest, and 10 liters per minute at rates of 120 beats per minute during moderate exercise.

APICAL LEFT VENTRICULAR-ABDOMINAL AORTIC COMPOSITE CONDUITS FOR LEFT VENTRICULAR OUTFLOW OBSTRUCTIONS.

Certain problems related to the left ventricular outflow tract are not amenable to conventional surgical methods, but may be solved with the creation of a double outlet left ventricle by using a composite rigid pyrolite left ventricular apex outlet prosthesis and a fabric valve-containing conduit. Low porosity woven Dacron tube grafts are used for the conduit. Twenty-three patients who have undergone apico-aortic bypass with this conduit are reported here, with gratifying results in eighteen.

DELAYED STERNAL CLOSURE: A USEFUL TECHNIQUE TO PREVENT TAMPONADE OR COMPRESSION OF THE HEART.

Closure of the sternotomy incision was limited to the skin in four critically ill patients following cardiopulmonary bypass. One patient had sustained an intractable bleeding diathesis and the other three had ventricular distention which prevented approximation of the sternum. All patients survived after delayed closure and repair of the sternotomy.