Gene A. Guinn

Herpesviridae in the endothelial and smooth muscle cells of the proximal aorta in arteriosclerotic patients

Punch-biopsy specimens were obtained from uninvolved areas of the proximal aorta of each of 60 patients with atherosclerosis undergoing cardiovascular surgery. Electron microscopic study of the smooth muscle and endothelial cells of the aortas showed cellular hyperplasia, nuclear and nucleolar atypia. Virions of the Herpesviridae family were observed in ten of the patients. They were detected in occasional smooth muscle and rare endothelial cells. Specimens were taken from three separate sites of each aorta and distributed into five blocks for each patient. In only a single block from each of the ten positive patients could virus be identified. Nine of the ten virus-positive patients also exhibited intracytoplasmic microtubular inclusions. In four patients only the microtubular inclusions were seen. Microcapillaries were observed in the midportion of the media, which we consider to be an attempt of a repair process.

Surgical treatment for stable angina pectoris. Prospective randomized study.

To evaluate the role of coronary bypass treatment of stable angina, 72 patients were randomly divided into surgical and medical groups. They were followed with treadmill tests and repeat catheterization. Anginal symptoms decreased or disappeared in 89 per cent of those operated on and 65 per cent of those not operated on, but more of the former than of the latter became asymptomatic: 69 vs. 11 per cent respectively (p smaller than 0.01). Exercise tolerance time improved significantly (p smaller than 0.001) in both groups, but more in the group operated on, plus 78 per cent vs. plus 48 per cent, p smaller than 0.05. During a 28-month follow-up period, fewer cardiac complications occurred in the patients operated on--14 vs. 34 (p smaller than 0.02). Mortality was 9 per cent in the patients operated on and 14 per cent in those not operated on; this difference is not significant. The results indicate that improvement, though demonstrable in both groups, is greater with surgery, and quality of life during the first 28 months is better in patients who are operated on.

Prosthetic valves in children and adolescents

The purpose of this paper is to present the short- and long-term results of prosthetic valve replacement in children. During a 7-year period that ended in April 1985, 186 children, ages 1 to 20 years, underwent valve replacement; there were 55 (30%) aortic valve replacements, 95 (51%) mitral valve replacements, and 36 (19%) multiple valve replacements. Ninety-four percent of the lesions were rheumatic in origin, 4% were congenital, and 2% were infectious. Of 223 valves replaced, 175 (78%) were mechanical valves and 48 (22%) were heterografts; the latter were in the mitral position in all but three patients. Surgical mortality rates were 3.6%, 4.2%, and 19.4% respectively for aortic valve, mitral valve, and multiple valve replacements. Five-year actuarial survival was 91% for aortic valve replacement, 82% for mitral valve replacement and 60% for multiple valve replacement. Major events included reoperation in 34 (with three deaths), progressive myocardial failure that led to death in 10, sudden unexpected death in two, thromboembolic complications in 19 (death in five), subacute bacterial endocarditis in five (two deaths), and bleeding that required transfusion in two patients. Five-year complication-free actuarial survival rates were 83% for aortic valve replacement, 63% for mitral valve replacement, and 57% for multiple valve replacement. The respective five-year complication-free survival rates were 83%, 48%, and 43%. Significant morbidity and mortality rates are associated with valve replacement. Therefore every effort should be made to preserve the native valve by plastic reparative procedures. When prosthetic replacement of mitral valve is contemplated, our data would suggest that heterografts should not be inserted in children 15 years of age or younger, although heterografts may be used in children over 15 years of age with the expectation of valve survival comparable to that of mechanical valves. When complications that are associated with anticoagulant therapy were reviewed, platelet inhibiting drugs seem quite satisfactory in patients with aortic valve replacement; patients with mitral valve replacement seem to require warfarin therapy, and warfarin must be used in patients with multiple valve replacement to reduce the risk of thromboembolic complications.

Anticoagulant therapy in children with prosthetic valves

The purpose of this study was to evaluate the effectiveness and complications of several types of anticoagulant therapy in children with prosthetic valves. During a 7-year period ending April 1985, 130 children aged 1 to 19 years underwent left-sided valve replacement. Operative mortality was 3%, 5%, and 9%, respectively, for aortic, mitral, and aortic and mitral valve replacement. Among the 123 survivors, 32 (26%) had had aortic, 71 (58%) had had mitral, and 20 (16%) had had aortic and mitral valve replacement. Follow-up ranged from 2 months to 8.2 years, a total of 544 patient-years. The survivors were divided into three groups based on anticoagulant treatment: warfarin sodium, aspirin plus dipyridamole, and no anticoagulants. Among the patients who had aortic valve replacement, thromboembolic complications developed in 2.5% (2.5/100 patient-years) of the aspirin plus dipyridamole group and 5% of the group given no anticoagulants. Only the warfarin group (4%) experienced bleeding complications. Among the patients having mitral valve replacement, thromboembolic complications developed in 4% of the warfarin group, 3% of the aspirin plus dipyridamole group, and 11% of the no anticoagulant group. In addition, 2% of patients in the warfarin group experienced severe bleeding. Two fatal cerebrovascular accidents occurred, both in the aspirin plus dipyridamole group. Patients who received a mitral heterograft were not prescribed any anticoagulant medications, and no thromboembolic complications developed. Among patients having double-valve replacement, complications developed in 5% of the warfarin group and 27% of the group given no anticoagulants.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of aryl hydrocarbon hydroxylase activity in human lung tissue, pulmonary macrophages, and blood lymphocytes.

Aryl hydrocarbon hydroxylase (AHH) activity was measured fluorometrically in surgically‐excised fresh lung tissue, pulmonary alveolar macrophages (PAMs), and peripheral blood lymphocytes from 14 cigarette smokers (7 with and 7 without primary lung cancer). Levels of AHH in fresh PAMs and AHH inducibility (expressed as fold‐induction) in cultured, mitogen‐stimulated lymphocytes from individual noncancer patients correlated well (r =0.975, p < 0.001). For individual lung cancer patients, however, these values were dissociated (linear regression not appropriate for this set of values). Levels of AHH in fresh lung tissue and fold‐induction ratios in cultured lymphocytes from individual noncancer patients also exhibited a positive correlation (r =0.976, p < 0.001), while values for individual lung cancer patients did not (r =0.007, p =0.987). A close agreement was noted for AHH in fresh lung tissue and fresh PAMs from individual noncancer patients (r =0.984, p < 0.001), while these values are weakly correlated for lung cancer patients (r =0.658, p < 0.11). When AHH activity in fresh PAMs, in fresh lung tissue, and AHH inducibility in cultured lymphocytes were simultaneously compared, an excellent relationship was observed for values for all 3 tissues for individual noncancer patients (r =0.987, p < 0.001). However, AHH levels in these 3 tissues from individual lung cancer patients were not correlated (r =0.701, p > 0.25). These results indicate similar capacity for AHH induction is present in fresh lung tissue, fresh PAMs, and cultured mitogen‐stimulated lymphocytes from cigarette smokers without evidence of lung cancer, but AHH values are not positively correlated with similar tissues from individual lung cancer patients.

Emergency Resection for Massive Hemoptysis

Abstract Pulmonary resection for massive bleeding was performed in 6 patients over a 5-year period at the Veterans Administration Hospital in Houston, Texas. A broad spectrum of diseases was represented, including 2 large lung cavities, 1 containing an aspergilloma, both of which were due to granulomatous processes; a metastatic sarcoma that was responding to cancer chemo-therapeutic drugs; 1 lobar atelectasis; 1 bronchiectasis; and 1 patient with persistent massive bleeding from an upper lobe that was normal on pathological examination. Our experience demonstrates that lung resection can control hemorrhage, but localizing the source of bleeding by bronchoscopy and limiting intrabronchial spread of blood during operation are important in the successful management of these patients.

Use of the Activated Coagulation Time in Intraoperative Heparin Reversal for Cardiopulmonary Operations

Activated clotting time (ACT) was used in 300 consecutive patients undergoing cardiac operations to determine the adequacy of heparin reversal. Mean ACT prior to protamine sulfate administration was 9 minutes 40 seconds. A return to normal value (less than 2 min 10 sec) occurred in three-fourths of our patients following administration of 1.5 mg of protamine sulfate for each 100 units of heparin. Additional protamine sulfate was administered in 50 mg doses to those having abnormal ACT until normal clotting was obtained. Normal values for ACT usually coincided with clotting in the operative field. ACT proved to be a reliable guide to protamine sulfate administration.

Surgical versus medical treatment for stable angina pectoris: prospective randomized study with 1- to 4-year follow-up.

A prospective randomized study to evaluate aortocoronary bypass was done on 116 patients (56 surgical, 60 medical) who had documented coronary artery disease (70% luminal obstruction in a major artery). The two groups were similar in age and risk factors. All patients have been followed for a mean of 34 months, and recatheterization has been done in 106 of the survivors. Important results show that although most patients in both groups are improved, more surgical patients are asymptomatic (68 vs 8%). Exercise tolerance was better in the surgical group (+94% vs +43%). There was significantly greater evidence of preinfarction angina in the medical group (p less than 0.02), but survival was similar.

Cardiopulmonary bypass in patients with previously completed stroke

It has been assumed that patients with neurological residua after a completed stroke are at increased risk of neurological complications associated with cardiac operations requiring cardiopulmonary bypass. To evaluate these assumptions, we reviewed retrospectively 1,163 consecutive patients undergoing cardiac operations with cardiopulmonary bypass. Among these 1,163 patients were 43 patients having a previously completed stroke with neurological residua, but without clinically significant extracranial carotid artery disease. Forty-one underwent coronary artery bypass grafting; of these, 1 required concomitant aortic valve replacement, 1 had mitral valve replacement, and 1 had aortic valve replacement. There was one death in this group of 43 patients, due to massive pulmonary embolism. Only 1 of these 43 patients experienced new neurological symptoms after operation, which would appear to indicate that patients with a previous, completed stroke may not be at increased risk of neurological complications from cardiac operations requiring cardiopulmonary bypass.

An Improved Mitral Valve Prosthesis

Abstract A Dacron velour–covered, Teflon-disc mitral valve prosthesis was developed in an effort to reduce thromboembolic complications of mitral valve replacement. A 12- to 28-month follow-up of 202 patients receiving these prostheses demonstrated only a 4.5% total incidence of such complications. However, a continuing search has been made for more durable materials. The most promising of these has been Pyrolite carbon, which now has been used for both the disc and the struts. Sacrifice of calves at intervals up to 12 months with scanning electron microscopical studies has demonstrated a disc and strut wear curve projecting 140 years prior to penetration of the Pyrolite carbon coating. Orifice and frustum areas of all sizes have been enlarged without change in mounting diameter. Clinical investigations of this prosthesis in several centers have been associated with as low an incidence of thromboembolic complications as that achieved with the Teflon-disc prosthesis. This improved prosthesis now has been released for general use.