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Biomedical subjects

W G Wolfe

Publications and source records attributed to W G Wolfe.

At least 73 records · Page 4Linked to original sources
PubMed1985

Electron microscopy in selection of patients with small cell carcinoma of the lung for medical versus surgical therapy.

Fifty-one cases of small cell carcinoma of the lung were studied by electron microscopy in order to determine if ultrastructural subsets could be found and if these subsets predicted clinical behavior. All of these cases were considered bona fide small cell carcinoma of the lung by light microscopy. Tumors with ultrastructural features of epithelial differentiation were defined by the presence of well-formed, classic desmosomes joining adjacent cells and by additional features of squamous or glandular differentiation. Thirty-one tumors (60%) were considered "typical oat cell" by electron microscopy and 20 (40%) showed features of epithelial differentiation. Fifteen (75%) tumors with epithelial features were considered operable and nine (45%) were resected with curative intent. In contrast, 26 (84%) tumors considered typical oat cell by electron microscopy presented with extensive metastatic disease. The cancer-free 5-year actuarial survival rate of patients whose tumors showed features of epithelial differentiation was 25%. The actuarial survival rate of nine patients who underwent resection of tumors with epithelial features was 38% at 5 years. Only one patient whose tumor was considered typical of oat cell carcinoma by electron microscopy survived 5 years. Our current recommendation is to remove all clinically resectable pulmonary neoplasms with the expectation that these localized small cell tumors are likely to show epithelial features by electron microscopic analysis.

Carcinoma, Small Cell↗
PubMed1984

Experimental and clinical use of the YAG laser in the management of pulmonary neoplasms.

Animal experiments were performed with evaluation of the use of the neodymium-YAG (yttrium-aluminum-garnet) laser in the trachea, bronchi, and pulmonary parenchyma. Histologic evaluation of incisions into the lung was assessed by multiple sections over a 5-week period and comparisons were made of incisions closed with chronic catgut or coagulated with electric cautery or by the laser. These studies indicated that the laser is more effective in controlling parenchymal bleeding and air leaks than either the cautery or chromic catgut and produces less local tissue reaction. The Nd-YAG laser has been used clinically to treat patients with inoperable obstructing and bleeding carcinomas of the trachea and main bronchi to open the involved airway and to restore pulmonary function. Fifteen patients have had 26 treatments using the Nd-YAG laser. Total laser time was limited to 15 minutes with 0.5-second pulses of 50 to 80 watts being delivered via the fiberoptic and straight bronchoscope as indicated. It is extremely effective in controlling hemoptysis from recurrent endobronchial lesions, and obstructing lesions in the trachea and main stem bronchus can be treated quite successfully with excellent palliation. It is apparent that continued clinical use of the Nd-YAG laser as palliative therapy for bleeding and obstructing tumors of the tracheobronchial tree is indicated and expanded use at the time of thoracotomy to control lung parenchymal bleeding and air leaks should be considered in the future.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1984

Surgical correction of type I dissecting aortic aneurysm after renal transplantation.

While Type III dissecting aneurysms of the aorta in patients with renal transplants have been described, this report appears to represent the first successful replacement of the ascending aorta with correction of valvar aortic insufficiency in a patient with a Type I aortic dissection. The operative result and subsequent clinical course have been gratifying. On the basis of these findings an aggressive surgical approach is recommended for patients with this combination of conditions.

Acute Disease↗
PubMed1984

Clinical characteristics and current management of medically refractory unstable angina.

Of 531 patients admitted to the Duke Coronary Care Unit with unstable angina (UA) from June 1981 to September 1982, 100 had persistent angina despite optimal medical therapy of nitrates, propranolol, and nifedipine. At catheterization, 70% of the refractory patients had left main (LM) or three-vessel disease (TVD), 68% had left ventricular end-diastolic pressures of greater than 12 mmHg, and 24% had ejection fractions (EF) of less than 0.40. Twenty-four patients were greater than 65 years of age, and 53 had associated major diseases. Forty-eight patients (Group I) had no evidence of myocardial infarction in the 30 days before catheterization, whereas 52 patients had an infarction precipitating the unstable angina within the preceding 30 days (Group II). Emergent coronary artery bypass grafting was performed in all 100 patients irrespective of ventricular function, hemodynamic status, or coronary anatomy. Management protocols included prompt surgical intervention, preoperative stabilization with the balloon pump in LM or TVD, meticulous myocardial protection, and complete coronary revascularization. An average of 3.6 grafts were placed in each patient. There were two hospital deaths in Group I, and two in Group II. Two-year survival was 90% in Group I and 88% in Group II, and 81% of surviving patients were NYHA Class I or II. Thus, refractory UA denotes particularly severe coronary disease with a high incidence of LM, TVD, and depressed EF. Baseline clinical characteristics, criteria for operation, and expected results in the postinfarction group seem to be similar to the unstable angina group in general. Cardiac anatomic and functional variables no longer constitute operative contraindications. Aggressive operative management is safe, and the current risk may be less dependent on coronary anatomy and ventricular function than previously appreciated.

Adult↗
PubMed1983

Surgical treatment of acute ascending aortic dissection.

Since adopting a policy of immediate operation on patients with acute dissection of the ascending aorta, 42 men and 6 women (ages 18-67 years) have been managed surgically. Thirty-two patients had graft replacement of the ascending aorta and resuspension of the incompetent aortic valve. One of these had a coronary graft. There were five deaths in this group. Eight patients required aortic valve replacement because of a diseased aortic valve as well as grafting of the ascending aorta, with one death. Three patients had resuspension of the aortic valve and primary repair of their dissection without mortality. Two patients were managed successfully with an intraluminal prosthesis and resuspension of the aortic valve. Another patient had successful repair with a valved conduit and reimplantation of the coronaries. Two patients dissected 4 and 6 years after aortic valve replacement and neither survived operative repair. Of the surviving patients, one required dialysis, one a femoral-femoral bypass graft, and one an axillo-femoral bypass graft. One patient required a pacemaker for heart block, and two underwent successful repair of suture line aneurysms, both occurring three years after operation. On the basis of this experience, prompt surgical intervention for acute ascending aortic dissection is the treatment of choice. A variety of techniques are available to repair the dissected aorta. Long-term results for resuspension of the aortic valve in acute ascending aortic dissection have been excellent and emphasize that valve replacement should be reserved for those patients found at operation to have a primary abnormality of the aortic valve.

Adolescent↗
PubMed1982

Comparison of plain radiography, conventional tomography, and computed tomography in detecting intrathoracic lymph node metastases from lung carcinoma.

Forty-two patients with T2 bronchogenic carcinoma were evaluated with plain radiography, conventional 55 degrees oblique hilar and anteroposterior mediastinal tomography, and computed tomography (CT) to compare their accuracy in assessing mediastinal and hilar nodal metastases. Definitive staging was achieved by thoracotomy and histopathological evaluation of resected specimens. All modalities demonstrated about the same accuracy; however, in the 25 patients with hilar and/or mediastinal lymphadenopathy, CT of the mediastinum was more sensitive but not more specific than the other two and conventional tomography was no more accurate than CT for hilar evaluation. Overall, no technique was accurate enough for routine staging; their value may lie in directing biopsy or in treatment planning in patients with inoperable disease.

Carcinoma, Bronchogenic↗
PubMed1982

Evaluation of the grafted ascending aorta with computed tomography. Complications caused by suture dehiscence.

Patients who have undergone surgery on the thoracic aorta and placement of a synthetic tubular graft need close, long-term radiological follow-up, as they are at risk of not only complications and progression of the underlying disease (atherosclerosis, dissection, or cystic medial necrosis) but also complications of the procedure, notably suture dehiscence leading to formation of an aneurysm around the graft. In a series of 14 asymptomatic postoperative patients studied by computed tomography (CT), the authors detected leakage of contrast material around the graft in 6 patients, 2 of whom required re-operation to correct suture dehiscence. CT is a noninvasive and sensitive method of postoperative evaluation of patients who have undergone an aortic graft.

Adult↗
PubMed1981

Renal artery stenosis in children.

Because high blood pressure in children is rare and most of these patients are asymptomatic, many are overlooked until they present with a hypertensive crisis or irreparable damage. Most children with renal artery stenosis are asymptomatic and the hypertension is detected only by blood pressure recording during physical examination. Angiography is the most helpful diagnostic study. It is generally agreed that renal artery lesions in children should be considered for surgical correction. An illustrated case is described.

Child↗
PubMed1981

The effect of altitude-induced hypoxia on regional myocardial blood flow.

Mechanical obstruction of the pulmonary artery causes an increase in right ventricular myocardial blood flow (MBF) proportional to the increased work load. This study was done to assess the response of MBF to hypoxia in the absence of mechanical obstruction of the right heart. The effects of hypoxia on cardiac performance and regional MBF were studied in ten awake, unanesthetized dogs at 4,600 m (15,000 feet). Intracardiac pressures and pulmonary artery (PA) and thoracic aorta blood gases were recorded daily, initially at sea level and subsequently at 3,000 m and 4,500 m altitude. Regional MBF was measured on days 1 (control), 3, and 5 by use of 8 to 10 mu radioactive tracer microspheres, followed by postmortem assessment of subepicardial and subendocardial flow patterns in the left ventricle (LV), septum, and right ventricle (RV) (4,600 m). The results indicate that: (1) RV and PA pressures increase linearly with increasing degrees of hypoxia, (2) MBF increases in both the RV and LV with increasing degrees of hypoxia and elevated right-sided pressures, without increased systemic pressure, and (3) the transmural distribution of MBF is unaltered in both the BV and LV with altitude-induced hypoxia. These findings are distinctly different from those in which right-sided pressures are elevated secondary to mechanical obstruction of the PA in the absence of hypoxia.

Altitude↗
PubMed1981

Effects of oxygen toxicity on regional ventilation and perfusion in the primate lung.

Since the effect of prolonged exposure to high concentrations of oxygen on regional ventilation and perfusion has not been previously, a reproducible primate model of oxygen toxicity was developed to investigate the pathophysiologic changes that occur. Regional ventilation and perfusion were measured by 133Xe techniques in 10 baboons before and after 108 hours of continuous exposure to an inspired oxygen concentration of more than 90%. Arterial blood gases, shunt fraction (QS/QT), cardiac output, physiologic dead space (VD/VT), and pulmonary vascular resistance were also measured. Light and electron microscopic histology confirmed early pathologic changes of oxygen toxicity in every animal after exposure. PaO2 in room air decreased markedly after exposure from 90 +/- 4 to 46 +/- 5 mm Hg, and QS/QT rose to 30 +/- 2%. VD/VT, PaCO2, and pH were not altered by exposure to hyperoxia. Similarly, cardiac output and pulmonary vascular resistance remained unchanged. The distribution of regional ventilation and perfusion remained normal during and after prolonged high-oxygen exposure. Early oxygen toxicity was characterized by profound hypoxemia without regional ventilation-perfusion mismatch. Although impaired diffusion through a thickened alveolar membrane may be partially responsible for this hypoxemia, the markedly increased alveolar-arterial oxygen gradient when FIO2 = 1.0 indicates that shunting at the alveolar level (secondary to absorptive collapse or pulmonary edema) is a major cause of the hypoxemia.

Animals↗
PubMed1981

Function of the secretory immune system in bronchogenic carcinoma. Immunoglobulin A levels in respiratory secretions.

This study was designed to investigate the association between bronchogenic carcinoma of the lung and elevated immunoglobulin A (IgA) levels in respiratory secretions. Sixty-nine patients underwent bronchoscopic examination for evaluation of benign and malignant pulmonary diseases. The concentration of IgA in bronchoscopic washings was determined by a radioimmunoassay (RIA) procedure. The average IgA concentration in 20 washings from patients with benign disease was 171 micrograms/ml and agreed with reported IgA values in normal human volunteers undergoing bronchoscopic examination. In contrast, the average IgA concentration from patients with non--oat cell bronchogenic carcinoma was greater than 1,000 micrograms/ml, and 80% of these patients had values exceeding 300 micrograms/ml. Furthermore, in 16 of these patients, selectively collected washings had been obtained from the tumor-bearing lung and contralateral normal lung. In this group, elevated levels localized to the tumor-bearing side. In contrast, eight patients with extrathoracic cancer metastatic to the chest had an average IgA value of 160 micrograms/ml, and seven of eight (87%) had concentrations below 300 micrograms/ml. Aside from the association of cigarette smoking and pulmonary cancer, we found no clear relationship between smoking history and the concentration of IgA measured in secretions. Finally, biochemical analysis established that the changes in immunoglobulin levels were specific to the secretory immune system. In conclusion, measurement of secretory immune system components may be useful in the early diagnosis of malignant bronchogenic disease. Biological mechanisms and suggested clinical application are discussed.

Adolescent↗
PubMed1980

Lung abscess and empyema of the thorax.

Empyema is best managed by the physician familiar with the indications and principals of the various procedures used in the treatment of empyema of the thorax. The objective of each modality used to treat empyema is to drain the pleura cavity and to allow full expansion of the lung. If the infected material can be removed and the visceral and parietal pleural approximated, the body will heal the pleural infection. The procedure chosen to treat empyema greatly depends upon the phase of maturation of the empyema when treatment is begun.

Adult↗
PubMed1980

Acute ascending aortic dissection.

Thirty of 33 patients (ages 18-67) with acute dissection of the ascending aorta underwent surgical intervention. There were four deaths. There were eight male and five female patients and 15 patients were known to be hypertensive. Severe chest pain, widened mediastinum (demonstrated radiographically), and varying degrees of aortic insufficiency were present in each patient. Heart failure was present in 13 patients, numbness and coolness of an extremity in seven patients, and central nervous system changes were present in three patients. The diagnosis in each instance was confirmed by aortography. Three patients treated nonoperatively died during hospitalization following aortic rupture into the mediastinum and pericardium. The remaining 30 patients were managed by insertion of a woven Dacron((R)) graft sutured distal to the coronary arteries and proximal to the origin of the great vessels. This was accompanied with resuspension of the aortic valve in 24 patients and valve replacement in six patients. Each of the latter six patients had a history of aortic valve disease. The goals of the operation were: 1) correction of the accompanying aortic insufficiency, either by valve replacement or resuspension of the valve and 2) placement of a prosthetic graft into the ascending aorta, thereby obliterating the false lumen and preventing involvement of the coronary arteries or rupture into the mediastinum or the pericardium. Hypertensive patients were managed pre- and postoperatively with nitroprusside and then with propranolol HCI, methyldopa, or hydralazine HCI and hydrochlorothiazide. One late death occurred six months after myocardial infarction and a second late death occurred from a presumed cardiac arrhythmia. One patient had a femorofemoral graft two months after the initial operation and another patient has mild aortic insufficiency. It is concluded that prompt surgical management is mandatory in acute ascending aortic dissection, and in most patients aortic valve competency can be re-established with resuspension of the valve preventing the added morbidity associated with a prosthetic valve. Four patients have been followed for five years and additional follow-up data will better define long-term survival.

Adolescent↗