Derward Lepley

Atherosclerosis of the internal mammary artery.

To better evaluate the incidence of atherosclerosis in the internal mammary artery (IMA), 215 IMA segments from routine postmortem examinations were evaluated microscopically. Significant atherosclerotic narrowing was seen in 9 patients (4.2%). No patient had more than a 50% reduction in lumen diameter. The degree of incipient atherosclerosis correlated well with age, hypertension, diabetes, and peripheral vascular disease.

Comparative Hemodynamic Properties of Vein and Mammary Artery in Coronary Bypass Operations

To understand better the observed differences in bypass flows between vein and internal mammary artery (IMA) grafts, a technique was devised for anastomosing both vein and IMA to the same anterior descending coronary artery in 14 patients. In the stable postperfusion state, flows in the two bypass conduits were simultaneously recorded as well as pressure relationships in both grafts and the left ventricle. The supply/demand ratio for left ventricular performance was calculated with respect to the diastolic pressure-time index/tension-time index (DPTI/TTI) for each bypass independently and simultaneously and then compared. The DPTI/TTI ratio was nearly two times greater with the vein bypass than with the IMA. This difference was further confirmed by the flow studies, in which blood flow through the vein ranged 2 to 3 times higher than IMA flow to the same coronary bed. By present criteria the DPTI/TTI ratio for IMA grafts to the left ventricle was inadequate in the majority of patients studied, and atrial pacing markedly lowered the DPTI/TTI ratio of the IMA. The choice of vein or IMA as a bypass is a critical determinant of the resultant bypass-left ventricular DPTI/TTI ratio. Vein bypasses exhibited far superior hemodynamic capability in the resting state, and the effect of atrial pacing on the DPTI/TTI ratio in IMA-vein-left ventricle bypasses confirms this point.

Long-Term Follow-up of the Björk-Shiley Prosthetic Valve Used in the Mitral Position

Abstract This study analyzes 547 patients who had mitral valve replacement with a Bjork-Shiley prosthesis over a 9-year period (mean follow-up, 46.5 months). Operative mortality was 7.3%, and 5-year survival was 76.9%. Serious anticoagulation problems occurred in 1.8% (10 patients) and serious thromboembolic episodes in 5.3% (28 patients) (1.3 per 1,000 patient-months). The study includes 257 patients with isolated mitral valve replacement (Group 1) and 290 who had associated procedures (Groups 2 through 5). Hospital mortality in Group 1 was 2.7% compared with 11.7% in Groups 2 through 5 ( p p In the patients in Group 1 with pure mitral insufficiency (MI), 5-year survival was 70.9%, significantly lower ( p Significantly lower ( p

Prognostic Considerations in the Management of Left Ventricular Aneurysms

This report summarizes a four-year experience with 60 patients who had left ventricular aneurysm (LVA) resection and bypass of all significantly diseased coronary arteries, with an operative and late mortality of 3.3 and 8.3%, respectively. Their cardiac catheterizations were reviewed, and the only values that seemed to reflect prognosis were preoperative cardiac index and the presence of absence of septal motion. The lower the cardiac index, the less likely the patient was to do well postoperatively. There were now survivors who had lacked septal motion by left anterior oblique ventriculogram. Patients without septal motion are therefore no longer considered surgical candidates. If septal motion is present, resection of LVA carries no more risk than myocardial revascularization without LVA.

An Alternative Approach to Isolated Circumflex Coronary Bypass Reoperations

Abstract A method for secondary and tertiary revascularization of circumflex marginal coronary arteries with descending aorta–coronary saphenous vein bypass grafts using an arterial occluder is described.

Ten-Year Follow-up in Aortic Valve Replacement Using the Björk-Shiley Prosthesis

An in-depth statistical analysis of early and late results of aortic valve replacement using the Björk-Shiley tilting-disc prosthesis is presented. Our experience with this prosthesis indicates that replacement carries a low surgical risk, a low incidence of complications (embolization, infection, or hemorrhage due to long-term use of anticoagulants), and good long-term survival. Coexisting coronary artery disease increases surgical mortality significantly, and simultaneous, complete revascularization is essential. Patients undergoing isolated aortic valve replacement did significantly better than those requiring other simultaneous procedures or those who had had previous operations. Earlier operation is imperative since progress of aortic valve disease is unpredictable by duration of symptoms, and patients in New York Heart Association Functional Class II have a low surgical risk and a greatly increased survival. It would appear from this study that additional criteria, such as increasing ventricular dilatation and hypertrophy determined by echocardiographic studies and gated nuclear studies showing deterioration of ejection fraction on exercise, should be used to help determine time of surgical intervention rather than symptomatology alone.

Late Results of Saphenous Vein Bypass Grafting for Myocardial Revascularization

Abstract Data from three large groups of patients undergoing aorta-to-coronary artery saphenous vein bypass grafting with follow-up angiograms between 0 and 32 months and postoperative clinical evaluation for up to 46 months enable us to say there is an early saphenous vein closure rate of 9%. These closures are probably related to technical judgment difficulties and lend themselves to improvement in results. The documented late closure rate in 92 patients followed a mean of 31.7 months was 13%. This is a rate of one late closure per 171 patient-months. Of the 92 patients, 80 had some effective vein graft functioning in this follow-up period. Histological evaluation has revealed subintimal fibrous hyperplasia to be the predominant factor involved in late closure of the vein bypass. Its manifestations are variable, and the multifactorial etiology is as yet unclear. Since 5% of vein grafts have some significant subintimal fibrous hyperplasia at the time of insertion, only close follow-up with correlation of operative, angiographic, and histological data will provide the answers to the question of etiology of late vein graft closure. Studies on the effect of trauma, vascularity, and nutrition of vein grafts are necessary. The answer to this problem will be necessary to set the coronary vein bypass procedure on a firm footing in the treatment of coronary artery disease.

Late Evaluation of Patients Undergoing Valve Replacement with the Björk-Shiley Prosthesis

This study analyzes 484 patients who survived mitral, aortic, or mitral and aortic valve replacement using the Björk-Shiley prosthesis from January, 1970, through December 31, 1974. Long-term follow-up of 1 1/2 to 6 1/2 years (mean, 3.67 yr) was done on 435 patients (98.2%). Eighty to 85% of the patients have improved noticeably. Thromboembolic problems occurred in 6.9%, representing 1.5 emboli per 1,000 patient-months. Anticoagulant bleeding problems occurred in 6.4% of the patients; late mortality was 15%. Actuarial survival curves showed patients at risk to 6 years having a 79% chance of survival. The same analysis according to preoperative New York Heart Association Functional Classification showed a striking reduction in survival in class IV patients. The Björk-Shiley prosthesis is a good choice for valve replacement today. Earlier diagnosis and treatment are needed to obtain better long-term survival.

Endomyocardial Fibrosis: A Surgical Approach

Abstract Endomyocardial fibrosis (EMF), a disease encountered in tropical areas, characteristically in Uganda, produces progressive endocardial restriction, heart failure, and ultimately death. To the present time no treatment has been effective in controlling the evolution of the process. The case of a young girl with EMF and unrelenting congestive heart failure is presented. Following an open-heart operation with excision of the fibrotic endocardium and replacement of the mitral valve, the patient is asymptomatic and has resumed normal life. This is the first case of endomyocardial fibrosis treated successfully and illustrates the feasibility of a new therapeutic approach to the entity. Open-heart operation should be considered in patients affected by this lethal disease.

Factors Predictive of Perioperative Myocardial Infarction during Coronary Operations

The diagnosis of perioperative myocardial infarction (PMI) in our patients was based upon electrocardiography, vectorcardiography, and postoperative enzyme changes. A group of 303 patients operated on between January and September, 1972, formed the basis of this study. Three groups were identified from among these patients. Group A was composed of 90 consecutive patients in whom MI was excluded by all criteria. Group B comprised 25 patients with proved MI and yielded the 8% incidence of MI among our patients. Group C included 34 patients with triple-vessel disease who did not sustain MI. Significantly more patients sustaining MI had preinfarction angina and severe coronary artery disease. The incidence of MI was also higher in patients with diffuse disease and those in whom the lesions could not be totally bypassed. A statistical correlation with longer pump runs and periods of anoxia was obtained. There was some suggestion that the preoperative location of the hypokinetic segment determined the site of MI in patients.