Biomedical subjects
Publications and source records attributed to H Hannah.
Postinfarction left ventricular thrombi are at risk for embolization with resultant injury. Surgical removal is recommended especially if they are pedunculated or mobile. We describe an easily applied transatrial method that can allow avoidance of a ventriculotomy.
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Salmonella is a rare cause of a mediastinal infection. This report describes the 14-year natural history of a mediastinal mass with eventual abscess formation. Computed tomography provided excellent visualization, and surgical drainage afforded prompt diagnosis and treatment.
To investigate the pathogenesis of respiratory lesions caused by the facultative intracellular pathogen, Rhodococcus equi, pulmonary clearance was compared in four groups of genetically defined mice, chosen for their specific deficits in immune and inflammatory responses. Complement-deficient A/J, immunodeficient nu/nu (nude), scid/scid.bg/bg (SCID/beige), C57BI/6J.bg/bg (beige) and normal Swiss mice (SW) received approximately 10(7) R. equi intranasally on day 0. Bacterial clearance was assessed in lung, liver and spleen on days 1, 4, 7 and 14. Pulmonary clearance was not significantly different between SW and A/J mice. Beige mice cleared R. equi more rapidly and completely than A/J and SW, indicating that deficits in phagocytic and NK cell function associated with the bg/bg gene did not compromise clearance. Pulmonary clearance in immunodeficient SCID/beige mice paralleled that of the SW and A/J mice initially but bacterial proliferation produced significant differences from SW mice at day 14. Nude mice were unable to clear R. equi from day 1, resulting in the death of two nude mice at day 11. Both SCID/beige and nude mice developed severe pyogranulomatous bronchopneumonia, whereas A/J and SW mice developed transient pulmonary lesions. Beige mice developed minimal lung lesions. Significant systemic bacterial proliferation occurred only in nude and SCID/beige mice. We conclude that deficiencies in complement components, phagocytic and NK cells do not impair the pulmonary clearance of R. equi but that a competent cellular immune system is required to prevent pneumonia and death. The difference in early phase pulmonary clearance in nude and SCID/beige mice indicates two phases are important for clearance. An acapsular mutant of R. equi was completely cleared from the lungs of SCID/beige mice suggesting an important role for the capsule in virulence for mice.
Infusion of unwashed mediastinal shed blood (MSB) is one technique advocated for decreasing use of donor blood in cardiac surgery patients. A commercially available system was prospectively evaluated in 96 consecutive patients. The control group was comprised of 78 consecutive patients. All underwent elective aortocoronary bypass surgery. Student's t-test, chi-square analysis, multivariate analysis, and Fisher's exact test were used where appropriate. There was no decrease in the amount of banked blood required or percentage of patients who received transfusions in the MSB autotransfusion group.
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A 64-year-old man underwent cardiac transplantation for long-standing severe dilated cardiomyopathy. Postoperative complications included primary cytomegalovirus (CMV) infection with several episodes of moderate acute rejection and severe pneumonia. Six months after transplantation, an endomyocardial biopsy specimen revealed focal necrotizing myocarditis with intranuclear inclusions consistent with CMV. The patient subsequently developed fulminant pneumonia and died 7 months after transplantation. Postmortem examination revealed that the cause of death was acute necrotizing bronchopneumonia due to Staphylococcus aureus, with underlying CMV pneumonitis. The transplanted heart had left ventricular hypertrophy with multiple organizing myocardial infarcts, moderate coronary atherosclerosis, and organizing thrombi of the left atrium. Characteristic inclusions of CMV were identified, predominantly within endothelial cells, in the left coronary artery, left ventricular endocardium, and myocardium. With in situ hybridization, the presence of CMV was verified in the inclusions, as well as in many fibroblasts without inclusions. In situ hybridization is warranted in myocardial biopsy specimens when suspicious inclusions or infiltrates are present, to confirm CMV infection, so that appropriate therapy can be initiated.
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Coronary angioscopy was used to assess the configuration and cross-sectional luminal area of atherosclerotic obstruction prior to and following laser recanalization in a patient at the time of bypass surgery. Angioscopy served as a useful adjunct to angiography by providing documentation of immediate improvement and patency of the laser-recanalized site.
Despite successful arterial thromboembolectomy, some extremities may have progressive ischemic necrosis due to persistent arterial occlusion. Streptokinase infusion can be valuable in this situation. We have developed a clinically applicable technique that is of value in lysing residual thrombi.
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Since 1971 we have employed the Morrow procedure in 30 patients with idiopathic hypertrophic subaortic stenosis (IHSS). All manifested obstruction to left ventricular outflow either at rest or with provocation (Valsalva) and 17 had moderate or severe mitral regurgitation. There were no operative deaths. Obstruction was abolished in all patients except one in whom a trivial 15-mm pressure gradient persisted, and all patients with moderate or severe mitral regurgitation evidenced marked amelioration of the mitral regurgitation. Distinct symptomatic improvement has been experienced by all patients, and 20 are entirely asymptomatic postoperatively. No patient has experienced syncope postoperatively although 15 experienced syncope before operation. In 12 patients the electrocardiogram recorded postoperatively was essentially unchanged from the preoperative record. In 16 patients a left anterior hemiblock was apparent postoperatively. In one patient a complete left bundle branch block appeared postoperatively and one patient demonstrated Wolff-Parkinson-White syndrome. One patient died suddenly and unexpectedly 2 years following operation. This patient continued to have palpitations after operation although all other symptoms as well as the left ventricular outflow obstruction were abolished by operation. It is suggested that propranalol administration be continued postoperatively in those patients experiencing palpitations or manifesting arrhythmias. Asymmetrical septal hypertrophy dislocates the cardiac apex and papillary muscles anteriosuperiorly producing abnormal systolic anterior mitral leaflet mition. The Morrow procedure restores more normal ventricular geometry and thereby eliminates the pathophysiological mechanism of obstruction and mitral regurgitation. The myotomies and myectomy should be extended far inferior through the entire width of the septum onto the free lateral ventricular wall. The procedure can be accomplished easily and safely through a transaortic approach. Since the operative risk at present appears to be negligible, prosthetic material is not required, and the risk of significant injury to the conduction tissue is small, we feel the current status of surgery for IHSS is such that the Morrow procedure should be performed earlier in the course of patients with IHSS manifesting obstruction or mitral regurgitation.
The coexistence of severe coronary artery and peripheral vascular lesions is not uncommon. Although diagnostic and sequential therapeutic techniques are standardized, the priority of surgical treatment is unresolved. Eight cases are reported in which simultaneous surgical correction of coronary atherosclerosis and carotid atherosclerosis, abdominal aortic aneurysm, or aortoiliac atherosclerosis was accomplished with success. Two additional cases demonstrate the complications which can occur when coexistent lesions are not corrected simultaneously. The surgical techniques employed are discussed. Because of these results, a further clinical trial seems warranted.
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Between 1970 and 1975, 234 porcine heterograft valve prostheses were implanted in 193 patients with 12 operative (6%) and 21 late deaths (11%). Detailed hemodynamic studies were made 6 months to 1 year following operation in 72 patients. Mean atrioventricular (A-V) diastolic pressure gradients averaged 5.2 mm Hg for 29 mm heterografts and 2.3, 2.5, and 2.7 mm Hg for 31 mm, 33 mm, and 35 mm heterografts, respectively. In 10 patients with aortic prostheses peak systolic gradients averaged 16 mm Hg at rest (range 0-26) but increased to 70 mm Hg during exercise (range 20-125). Anticoagulants were not used except when intracardiac clot was present at operation. There were 12 systemic arterial emboli, all with mitral prostheses and low cardiac output; nine patients were in atrial fibrillation and three were in sinus rhythm. Three patients evidenced late tissue failure. Hydraulic function in the A-V position is excellent: prosthetic valve size is not limited by tertiary orifice and A-V anulus accepts large prosthesis. The patient's anulus is the determinant of aortic prosthesis size; heterograft internal diameter to outside diameter ratio is suboptimal and hydraulic function of the aortic prosthesis is marginal. In our clinical practice we consider the performance characteristics of currently available valves in relation to the individual patient's priorities to select an appropriate prosthesis.
A retrospective analysis was undertaken of clinical data and catheterization studies of 151 consecutive unselected patients who underwent aorta-coronary bypass at the University of Kansas Medical Center between 1971 and 1973. The purpose was to determine the effect of preoperative left ventricular function and extent and severity of coronary artery obstruction on operative mortality rate and long-term survival. The postoperative follow-up period ranged from 10 to 49 months and averaged 26 months. Left ventricular function was assessed by qualitative analysis of left ventricular angiograms. Severity of coronary obstruction was quantified by scoring coronary arteriograms according to the system of Friesinger and associates. Patients with normal or near normal ventriculograms were considered to have good left ventricular function. Patients showing moderate or severe impairment of contraction were considered to have poor left ventricular function. Obstruction scores ranging from 2 to 7 points were classified as low scores, and scores from 8 to 15 points were classified as high scores. Four groups of patients were identified based upon preoperative left ventricular function and obstruction severity: Group I, 29 patients with good left ventricular function and low scores; Group II, 22 patients with poor left ventricular function and low scores. Group III, 28 patients with good left ventricular function and high scores. Elective aorta-coronary bypass in these three groups was accompanied by no operative or late deaths. Group IV comprised 72 patients with poor left ventricular function and high scores. In this group there was a 10 per cent operative mortality rate (7 of 72 patients) and a 5 per cent year late mortality rate. Relief of angina occurred equally in all groups. Thus operative risk can be prospectively determined by analysis of left ventricular function and severity of coronary obstruction. Surgical treatment resulted in negligible operative and late mortality rates (0 per cent) in all patients except those in whom poor ventricular function was accompanied by severe and diffuse coronary artery obstruction. Operation should be offered to this latter group (Group IV) despite the higher operative and postoperative risk because of salutary postoperative results.