Studies with the Total Artificial Heart Using Sheep as an Adult Animal Model

The sheep was developed as an adult animal model for artificial heart research at the University of Utah. A JARVIK-7™ pneumatic total artificial heart, designed for human use (stroke volume 100ml), was implanted in 43 sheep from 1980 through 1983. Experimental results from these implanted sheep indicate excellent hemodynamic performance of the pneumatic heart system, insignificant mineralization of the pumping diaphragm, and stable laboratory values and body weight. The longest survival time was 297 days in 1982. The sheep has proven to be a good experimental model for the long-term testing of a total artificial heart. However, because of several problems, the average survival days of these sheep was not consistently extended; 63 days in 1980 (5 cases), 12 days in 1981 (15 cases), 71 days in 1982 (8 cases), and 30 days in 1983 (15 cases). From the analyses of the experimental data of these sheep, as current problems, postimplantation hemolysis, renal failure, pulmonary dysfunction, infection with vegetative thrombus, mechanical accident, and renal infarctions are identified, and the mechanisms of these problems are discussed. Further study is needed to identify the mechanisms to eliminate postimplantation hemolysis, renal failure, and pulmonary dysfunction, to consistently obtain long-term surviving sheep. For long-term survival, prevention of infection is an important factor. A cardiac output monitor and diagnostic unit (COMDU™) was used for the cardiac output measurement and evaluation of the hemodynamic performance of the ventricles, which proved to be very useful for animal and human application of the pneumatic total artificial heart.Some sections of this manuscript were presented at the Fourth Congress of the International Society for Artificial Organs, Kyoto, Japan in 1983. This work was supported in part by grants from the National Institutes of Health via the National Heart, Lung, and Blood Institute's grants number HL-24561 and by the Development Fund of the Division of Artificial Organs, to which contributions have been made by many generous donors including: Ethicon Laboratories, Ben Matthews, Digital Equipment Corporation, and Square-D Foundation

Experimental Evaluation of Bretschneider's Solution for Myocardial Preservation in Cardiac Transplantation

Myocardial preservation by Bretschneider's solution (BR solution, Group I) with an intracellular like electrolyte and histidine buffer action was compared with EC-Bi solution (Group II) which has an extracellular like electrolyte and bicarbonate buffer action in the mongrel dogs. The PH and PCO2 of the effluent from the coronary sinus were maintained during myocardial ischemia for 3 hr but the lactate rose gradually in group I. The oxygen and lactate up-take ratio of the myocardium after re-perfusion was satisfactory and LV max dp/dt was also maintained at a high level in group I. Morphologically, myelin figure and mitochondrial deformation were more found in group II on electron microscopy. A donor heart preserved for 3 hr in cold BR solution was transplanted in the left thoracic cavity in four mongrel dogs by the technique of the heterotopic cardiac transplantation. Resuscitation of cardiac pulsation was smooth and maintenance of the systemic circulation after transplantation was possible in every case. From these findings, it might be concluded that myocardial preservation using cold BR solution was useful for cardiac transplantation

Post-traumatic diaphragmatic herniation of the liver, examined by positron emission tomography: case report

We present a case of post-traumatic diaphragmatic herniation of the liver, which mimicked an intrathoracic tumor. After an automobile accident, the patient underwent thoracotomies for hemothorax and lung cancer in the right chest. Seven months later, computed tomography (CT) demonstrated a round tumor in the thorax adjacent to the right diaphragm with a higher density than the liver parenchyma. An intrathoracic tumor including a primary or metastatic lung cancer was suspected. However, positron emission tomography (PET) showed that the uptake of fluorine-18-fluorodeoxyglucose (FDG) was identical to that in the liver, and the tumor appeared to be contiguous with the liver. Thus, we suspected liver herniation. Core needle biopsy revealed liver cells without neoplastic tissue. Upon surgical exploration, herniation of the liver was found and repaired. PET was helpful in providing morphological and functional information leading to accurate diagnosis of liver herniation in this unusual case

Clinical Analysis of 110 Postoperative Deaths of the Patients with Permanent Implantable Pacemaker

During 14 years follow up of 754 patients received permanent cardiac pacemaker (PM) implantation, 110 cases have died. In this paper, the cause of death of them was clinically analyzed. The death to senility was most frequent, in 31 cases out of 110 deaths (28.2%), and then heart failure in 19 cases (17.3%), cerebrovascular disease in 16 cases (14.5%), sudden death in 14 cases (12.7%), malignancy in 7 cases (6.4%), acute myocardial infarction in 7 cases (6.4%), severe infectious disease in 4 cases (3.6%), unknown etiology in 4 cases (3.6%), renal failure and Disseminated Intravascular Coagulation Syndrome (DIC) in 2 cases (1.8%), respectively, suicide in one case (0.9%). Cause of death by underlying disease was rather characteristic. Senility was frequent in the patients with atrioventricular (A-V) block (38.5%), while cerebrovascular disease was highly observed in the patients with Sick Sinus Syndrome (SSS) (28.1%), and heart failure was highly observed in the patients with atrial fibrillation (46.2%). Senility was seen in 44.8% of the patients with coronary arteriosclerosis, cardiac death in 85. 7% of the patients with cardiomyopathy, and in 100.0% of the cases with valvular disease. The above mentioned fact suggests that cardiovascular check up is most important in postoperative follow up of the patients with PM. In old cases, senility and infection were major cause of death, so guidance concerning to dietary life and periodical health examination against wasting disease is important especially in this group. And, active care for heart failure is also more important in the patients with cardiomyopathy and valvular disease

Neointimal characteristics comparison between biodegradable-polymer and durable-polymer drug-eluting stents: 3-month follow-up optical coherence tomography light property analysis from the RESTORE registry

We aimed to quantitatively assess a possible difference of the neointimal quality between biodegradable polymer- (BP-) and durable polymer drug-eluting stents (DP-DESs). We conducted a single-center all-comer prospective cohort study: the RESTORE registry (UMIN000033009). All patients who received successful OCT examination at planned 3-month follow-up after DES implantation were analyzed. Study population was divided into 2 groups, BP-DES versus DP-DES groups. We evaluated standard OCT variables, coverage percent, and the quantitative light property values including light intensity, attenuation, and backscatter. We performed OCT analyses of 121 lesions in 98 patients (BP-DES 55 lesions in 51 patients vs. DP-DES 66 lesions in DP-DES 53 patients). Lesion and procedural characteristics were overall well-balanced between both groups. At 3-month follow-up, neointimal thickness (BP-DES 49.3 [38.2, 57.7] µm versus DP-DES 54.7 [45.1, 70.7] µm, p = 0.059) and coverage percent (BP-DES 94.5 [89.8, 97.0]% vs. DP-DES 95.8 [91.1, 98.1]%, p = 0.083) did not significantly differ. Light intensity of superficial neointima in the BP-DES was lower than that in the DP-DES, whereas that of deep neointima did not differ between both groups

A Case Report of Intraatrial Thrombus with Echogenic Blood Stasis Examined by Transesophageal Echocardiography

Using transesophageal echocardiography (TEE), intraatrial thrombus was visualized clearly with fine mistlike echoes which are reported to be detected when the blood flow is stagnant or ceased. The echoes showed slow, clockwise, circular movement in the left atrium, and were confirmed to show the real flow with two-dimensional color Doppler TEE. They were different from those echoes seen as contrast echoes which are more coarse, more echogenic, and accompanied with slight side lobes. TEE demonstrated slight mitral regurgitation which was not detected with conventional echocardiography conducted preoperatively. It is not certain whether such slight regurgitation has some clinical significance or not. However, accompanied with drainage flow from the pulmonary veins, the trivial regurgitation seemed to cause slow circulatory movement in the left atrium and turbulant flow around the left auricle. As we previously reported, the blood in the left atrium is strongly stirred in the cases or marked mitral regurgitation. This might explain the reason why the intraatrial thrombus is rarer in the case of mitral regurgitation than in pure mitral stenosis