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Biomedical subjects

A DeBoer

Publications and source records attributed to A DeBoer.

7 recordsLinked to original sources

The role of the lymphatic system in coronary atherosclerosis.

Arguments are presented to support the hypothesis that the integrity of the coronary lymphatic system is an important factor in the development of coronary atherosclerosis. It is proposed that the lymphatic drainage of the epicardial coronary arteries is genetically inadequate, and that the flow of lymph from the heart is further impaired by gravitational factors due to man's upright position. Arguments are presented to support the concept that the intramural coronary arteries are protected from atherosclerosis because of a highly effective pericoronary lymphatic and venous capillary system and that the internal thoracic (internal mammary) artery is similarly protected from atherosclerosis because of its close relationship to an extensive lymphatic chain. It is proposed that the failure of the cardiac lymphatic system in the allogenic transplanted heart is a cause of the accelerated atherosclerosis in both epicardial and intramural coronary arteries.

Animals

The efferent cardiac lymphatic pathways in the macaque monkey.

In ten postmortem hearts of the Macaque monkey (M. mulatta), the coronary lymphatics were visualized using an India ink suspension in 2% gelatin. The left coronary lymphatic initially passed to the dorsal surface of the aortic arch. In five hearts, this lymphatic went directly to the cardiac lymph node, whereas in the others, it first ascended to the left superior tracheobronchial node and then interconnected with the cardiac lymph node. The right coronary lymphatic usually passed in front of the ascending aorta and common arterial (brachiocephalic) trunk and entered the cardiac lymph node. In two hearts, however, the right coronary lymphatic first ascended to an anterior transverse mediastinal node and from here lymphatics joined the cardiac lymph node. Those lymphatics that passed cephalad from the cardiac lymph node to the right anterior mediastinal nodes and the right paratracheal nodes ultimately emptied into the right venous angle. Those lymphatics that passed cephalad from the cardiac lymph node to the anterior transverse mediastinal nodes ultimately emptied into the left venous angle. In five other Macaque monkeys (M. mulatta and M. fascicularis) after marker injection (T1824 blue dye and micropulverized barium sulfate) into the living heart or pericardium, lymphatic drainage beyond the base of the heart could not be demonstrated. Whereas postmortem morphologic studies suggest that the monkey coronary lymphatic system is amenable to obstruction by removal of the cardiac lymph node and interruption of its adjacent lymphatic connections, effective methods for visualizing the mediastinal lymphatic collecting system in the living monkey must be developed before experimental cardiac lymphatic ablation can be accomplished in this species.

Animals

Taussig-Bing anomaly with straddling mitral valve.

Five patients with the left-sided or intermediate type (Lev) of the Taussig-Bing anomaly were found to have an associated straddling of the mitral valve. In four patients the anomaly of the mitral valve was not recognized preoperatively, and all four died postoperatively. The persistent subpulmonic obstruction caused by the abnormal attachment of the anterior mitral leaflet is considered a significant factor in the poor operative outcome. Retrospective study of angiograms in these four patients revealed diagnostic clues of straddling mitral valve which enabled us to diagnose a fifth patient angiographically and confirm the diagnosis by cross-sectional echocardiography. A surgical approach to correct this association of abnormalities is proposed which avoids operating upon the mitral valve. Its function is thereby preserved, yet the hemodynamic problem caused by the straddling is bypassed. The fifth patient in this series was successfully treated by the proposed operative method.

Adolescent

A case of myocardial abscess evaluated by radionuclide techniques: case report.

A patient with infective endocarditis was evaluated by Ga-67 citrate imaging, Tc-99m pyrophosphate imaging, equilibrium gated blood pool imaging, and Tl-201 imaging of the chest. The diagnosis of ventricular abscess was first suggested by an abnormal gallium scan. At surgery, an abscess was identified in the area where the scan was abnormal, and postoperatively a repeat scan was normal.

Abscess

Postperfusion coronary ostial stenosis: incidence and significance.

In a study of 117 consecutive aortic valve replacements in which selective coronary perfusion was routinely employed, four patients developed coronary ostial stenosis (3.5 per cent). Continuous selective coronary perfusion was performed by use of Mayo balloon catheters with individual measuring of pressure and flow. All 4 patients developed progressive symptoms of angina pectoris within 6 months of the original operation, after uneventful recoveries. All 4 were found to have lesions in the left main coronary ostium and required a coronary bypass. Two made uneventful recoveries and are presently asymptomatic, whereas 2 died in the immediate postoperative period. The literature indicates that the reported incidence of this complication varies from 1 to 5 per cent. Furthermore, the mortality rate for reoperation in these patients is higher than that for those undergoing uncomplicated coronary bypass without an antecedent procedure. Our experience confirms the lethal nature of this complication and the necessity for reoperation once the diagnosis is established. The development of these dangerous lesions must be taken into account in the prevailing controversy between the most effective methods of myocardial protection during aortic valve replacement.

Adult