Search PubMed⌕ Search

Biomedical subjects

K G Evans

Publications and source records attributed to K G Evans.

31 records · Page 2Linked to original sources
PubMed1989

Comparison of single breath carbon monoxide diffusing capacity and pressure-volume curves in detecting emphysema.

To evaluate the sensitivity of diffusing capacity (DLCO) and pressure-volume (P-V) curves in the detection of emphysema, these tests were compared with pathologic assessment of emphysema in patients undergoing lung resection for a localized tumor, and with the overall extent of emphysema as assessed by computed tomography (CT). The resected lung specimens were fixed in the inflated state and cut at 1-cm intervals in the horizontal plane. The pathologic extent of emphysema was quantitated by comparison with a standard reference panel of emphysema grading. The overall extent of emphysema on CT was assessed by a visual scoring system in a total of 55 patients, 19 undergoing lung resection and 36 not undergoing lung resection. Analysis of 37 patients by pathology scores revealed 18 with no or trivial emphysema (emphysema grades less than or equal to 5; mean grade, 2.2 +/- SD 2.6) and 19 with emphysema (grades greater than or equal to 10; mean grade, 33.2 +/- SD 24.2). Diffusing capacity, the ratio of DLCO to alveolar volume (DLCO/VA), maximal lung elastic recoil (PLmax), and lung elastic recoil at 90% of total lung capacity (PL90) were significantly different between the two groups, whereas K (the exponential constant describing the shape of the P-V curve) was not. The pathology grade of emphysema showed a significant correlation with (DLCO) (r = -0.53) and DLCO/VA (r = -0.55), which was greater than the correlation with PLmax (r = -0.42) and PL90 (r = -0.43).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Multicentricity of adenocarcinoma of the lung.

In a consecutive series of 62 lung resections for bronchogenic adenocarcinoma, 12 patients (19 percent) were found to have two or more adenocarcinomas on careful pathologic examination. These tumors all met the criteria for separate primary malignancy. In only two of the patients were the additional lesions suspected preoperatively. This incidence of multiple primary lung adenocarcinomas in apparently operable patients is several fold higher than would be anticipated from the literature. The phenomenon has important implications for preoperative radiologic evaluation, postoperative pathologic examination, assignment of TNM stage, and clinical follow-up of patients undergoing successful resection.

Adenocarcinoma↗
PubMed1989

Primary anterior mediastinal tumours: "an investigational algorithm".

A review of 33 months' experience with primary anterior mediastinal masses in 31 patients disclosed that in 9 (29%) the tumour was benign. Nineteen (86%) of the 22 malignant tumours and only 2 of the 9 benign tumours were symptomatic. Diagnosis was established by histopathologic examination of a biopsy specimen or resected tissue and serum radioimmunoassay for alpha-fetoprotein or human chorionic gonadotropin, beta-subunit. The authors present an investigational algorithm, using modern procedures, to facilitate the diagnosis of this relatively uncommon and challenging condition.

Adolescent↗
PubMed1988

Glandular neoplasia of the lung. A proposed analogy to colonic tumors.

In 62 consecutive resections for adenocarcinoma of the lung, 50 cases (81%) had single adenocarcinomas and 12 (19%) had multiple adenocarcinomas. In seven of these 12 patients, two adenocarcinomas were found. In the other five patients, the specimen contained a dominant adenocarcinoma and several 0.1- to 1-cm nodules of similar histologic appearance. In four of the 50 single tumor patients and one of seven double tumor patients, 1- to 2-mm nodules were found along with adenocarcinomas that we interpreted as being bronchioloalveolar tumors of uncertain malignant potential. An analogy is drawn between these four types of findings and single tumors of the colon, double tumors of the colon, polyposis syndromes, and tubular adenomas of the colon, respectively.

Adenocarcinoma↗
PubMed1988

Resectable stage III lung cancer: CT, surgical, and pathologic correlation.

The new International Staging System identifies a subset of patients with stage III lung cancer who have improved survival rates after surgical resection. The computed tomographic (CT), surgical, and pathologic findings in 26 patients with completely resected stage IIIa lung cancer were reviewed. Preoperative CT scans accurately demonstrated chest wall invasion in only two of ten patients with chest wall or diaphragmatic invasion. CT demonstrated pericardial involvement in only one of three patients. Tumor extension to within 2 cm of the tracheal carina was seen with CT in one of three patients. Eleven of 26 patients had limited ipsilateral mediastinal (N2) disease; eight of 11 had affected nodes greater then 10 mm on CT scans. As previously shown, CT is of limited value in the assessment of chest wall, mediastinal, pleural, or pericardial tumor extension; however, such extension does not preclude complete resection. Ipsilateral node involvement does not preclude surgery. Familiarity with the new staging system and awareness of what constitutes potentially resectable disease are necessary for an adequate assessment of CT findings.

Adult↗
PubMed1988

Mediastinal nodes in bronchogenic carcinoma: comparison between CT and mediastinoscopy.

Computed tomography (CT) and mediastinoscopy were compared in 151 patients with bronchogenic carcinoma. In all patients in whom findings at mediastinoscopy were negative, all accessible nodes were either removed or sampled at thoracotomy. Several size criteria for identifying nodes as enlarged on CT scans were compared. The long axis greater than or equal to 15 mm and short axis greater than 10 mm had very low sensitivity (61%), and the long axis greater than 5 mm had a low specificity (23%). CT (long axis greater than 10 mm) allowed sensitivity equal to that of mediastinoscopy (79%) in the detection of mediastinal metastases, but the specificity with CT was lower (65% vs. 100%). In seven of 44 patients with nodes greater than 10 mm on CT scans and with positive findings at mediastinoscopy, tumor was present not in the enlarged nodes but rather in normal-sized nodes in a different nodal station. The sensitivity of CT for actual nodal stations involved with tumor was only 66%. Eighty-three percent of patients with false-negative findings at mediastinoscopy but only 33% of patients with false-negative findings at CT had surgically resectable stage IIIa disease.

Carcinoma, Bronchogenic↗
PubMed1987

Lingular and right middle lobe biopsy in the assessment of diffuse lung disease.

It has been said that the lingula and right middle lobe should be avoided for open-lung biopsy because of nonspecific fibrosis and vascular changes. To determine if the diagnostic yields of lingular or right middle lobe biopsy specimens were unsatisfactory, we reviewed the results of open-lung biopsy in 73 adult patients; 26 were immunocompromised and 47, nonimmunocompromised. We found no evidence to suggest that these two sites were inherently inferior. In 20 of the nonimmunocompromised patients, computed tomography was performed prior to biopsy, and demonstrated no particular tendency for greater involvement of the lingula or right middle lobe. We conclude that lingular and right middle lobe biopsy is useful in the diagnosis of parenchymal lung disease and that these sites should not necessarily be avoided. Computed tomographic scanning prior to biopsy is helpful in guiding the surgeon to the appropriate sites from which to obtain biopsy specimens.

Adult↗
PubMed1986

Fibrosing alveolitis: CT-pathologic correlation.

Computed tomography (CT) was performed within 10 days of open lung biopsy in nine patients with fibrosing alveolitis. One-centimeter collimation contiguous scans through the chest were obtained in all patients. Additional 1.5-mm collimation scans were obtained in the area in which lung biopsy was later performed in six patients. In seven patients, CT demonstrated patchy involvement of the lung parenchyma, areas with a reticular pattern being intermingled with areas of normal lung. The reticular pattern was associated with cystic spaces 2-4 mm in diameter and was more severe in the lung periphery. Histologically, the reticular pattern corresponded to areas of irregular fibrosis. One patient had diffuse honeycombing (2-20-mm cysts), and one had honeycombing only in the lung periphery. In all patients, CT clearly defined the architectural changes seen on open lung biopsy. These changes were much better seen on the 1.5-mm than on the 10-mm collimation scans. CT may be helpful in determining the pattern and distribution of lung involvement in patients with fibrosing alveolitis and in guiding the surgeon to the most appropriate area(s) for biopsy.

Adult↗
PubMed1986

Alveolar epithelial damage. A critical difference between high pressure and oleic acid-induced low pressure pulmonary edema.

The present study was designed to compare high pressure pulmonary edema (HPPE) and oleic acid-induced low pressure pulmonary edema (OAPE) in dogs when similar amounts of extra vascular water were present in the lung. The high pressure edema was produced by intravenous fluid overload and by inflating an aortic balloon catheter (n = 6). The low pressure edema was produced by the injecting 0.08 mg/kg oleic acid suspended in 5 ml saline (n = 6). Comparison of the difference between initial control measurements and final measurements in the edematous states showed that the animals with OAPE had a greater fall in percent oxygen saturation and a greater increase in shunt fractions. The light microscopic studies showed that OAPE was associated with greater amounts of alveolar flooding than HPPE where the edema fluid was located to a greater extent in the peribronchial interstitial space. The electron microscopy studies showed that the alveolar flooding in OAPE was associated with epithelial disruption, and tracer studies carried out in rabbits showed that dextran (150,000 mol wt) could pass from blood to airspace and that dextran (40,000 mol wt) could pass from air-space to blood in OAPE. We conclude that epithelial disruption is responsible for the excessive alveolar flooding in OAPE and that this results in a greater impairment in gas exchange.

Animals↗
PubMed1979

Jejunoileal bypass and the defunctioned bowel syndrome.

Sixty-six patients who had a jejunoileal bypass with ileosigmoidostomy for intractable obesity were reviewed. Thirty-three patients had sudden, severe, upper pain develop in the abdomen with distention from one to four years after the original operation. All 33 patients had a repeat laparotomy from one to six years after the initial bypass procedure. In every instance, a dilated, hypertrophied defunctioned ileum was found proximal to the ileosigmoidostomy. In 11 patients, an ileosigmoid volvulus was present. In every instance, the ileosigmoid anastomosis was dismantled and an end-to-side ileotransversostomy performed. In one patient, an ileal volvulus developed proximal to the ileotransversostomy because of an inadvertent technicality and this was corrected by reoperation. The remaining 32 patients have been asymptomatic since the ileosigmoidostomy was converted to ileotransversostomy. To date, in more than 200 primary operations for morbid obesity, the ileum has been drained into the transverse colon. None of these patients have had obstruction of the defunctioned small bowel develop.

Colon, Sigmoid↗