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Biomedical subjects

W Weder

Publications and source records attributed to W Weder.

At least 73 records · Page 4Linked to original sources
PubMed1998

Detection of extrathoracic metastases by positron emission tomography in lung cancer.

BACKGROUND: Accurate staging of non-small cell lung cancer is essential for treatment planning. We evaluated in a prospective study the role of whole-body 2-[18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in mediastinal nodal staging with a positive predictive value of 96%. The study was continued to further evaluate the value of whole-body FDG PET in detecting unexpected extrathoracic metastases (ETMs) in patients qualifying for surgical treatment by conventional staging. METHODS: One hundred patients underwent clinical evaluation, chest and upper abdominal computed tomography scan, mediastinoscopy (lymph nodes greater than 1 cm on computed tomography), and routine laboratory tests. In 94 patients with stage IIIa or less and 6 with suspected N3 a whole-body FDG PET was performed. If clinical signs of ETMs were present additional diagnostic methods were applied. All findings in the FDG PET were confirmed histologically or radiologically. RESULTS: Unexpected ETMs were detected in 13 (14%) of 94 patients (stage IIIa or less) at 14 sites. In addition 6 of 94 patients were restaged up to N3 after PET. The suspected N3 disease (stage IIIb) on computed tomography was confirmed by PET in all 6 patients. There was no false positive finding of ETM. Weight loss was correlated with the occurrence of ETM: more than 5 kg, 5 of 13 patients (38%); more than 10 kg, 4 of 6 patients (67%). Pathologic laboratory findings were not predictive for ETM. CONCLUSIONS: Whole-body FDG PET improves detection of ETMs in patients with non-small cell lung cancer otherwise elegible for operation. In 14% of patients (stage IIIa or less), ETMs were detected, and in total, 20% of the patients were understaged.

Adenocarcinoma↗
PubMed1998

Effect of soluble complement receptor type 1 on reperfusion edema and neutrophil migration after lung allotransplantation in swine.

OBJECTIVE: Soluble complement receptor type 1 inhibits complement activation by blocking C3 and C5 convertases of the classical and alternative pathways. We evaluated the effect of soluble complement receptor type 1 on lung allograft reperfusion injury. METHODS: Left lung transplantation was performed in 13 weight-matched pigs (25 to 31 kg) after prolonged preservation (20 hours at 1 degree C). One hour after reperfusion the recipient contralateral right lung was excluded to assess graft function only. Complement activity and C3a levels were measured after reperfusion and at the end of the assessment. Extravascular lung water index, intrathoracic blood volume, and cardiac output were assessed during a 5-hour observation period. Gas exchange and hemodynamics were monitored. At the end of the 5-hour assessment period, myeloperoxidase assay and bronchoalveolar lavage were performed to assess neutrophil migration, and C5b-9 (membrane attack complex) deposits in the allograft were detected by immunohistochemistry. Two groups were studied. In group II (n = 6) recipient animals were treated with soluble complement receptor type 1 (15 mg/kg) 15 minutes before reperfusion. Group I (n = 7) served as the control group. RESULTS: Serum complement activity was completely inhibited in group II. In contrast to group I, C5b-9 complexes were not detected in group II allograft tissue samples. C3a was reduced to normal levels in group II (p = 0.00005). Extravascular lung water index was higher in group I animals throughout the assessment period (p = 0.035). No significant difference in allograft myeloperoxidase activity (p = 0.10) and polymorphonuclear leukocyte count of the bronchoalveolar lavage fluid (p = 0.057) was detected. CONCLUSION: Inhibition of the complement system by soluble complement receptor type 1 blocks local complement activation in the allograft and reduces posttransplantation reperfusion edema but does not improve hemodynamic parameters.

Animals↗
PubMed1998

Effect of lung volume reduction surgery on pulmonary hemodynamics in severe pulmonary emphysema.

OBJECTIVE: The presence of pulmonary hypertension in severe pulmonary emphysema has been considered a relative contraindication to lung volume reduction surgery (LVRS). There was concern that resection of lung tissue might further increase pulmonary artery pressure. To address this point, the prevalence of pulmonary hypertension in candidates for LVRS was investigated. The changes in pulmonary artery pressures after bilateral videoassisted thoracoscopic resection was studied in patients with homo- and heterogeneously destroyed emphysematous lungs. DESIGN: The pulmonary arterial pressures by right heart catheterization were prospectively assessed, before and 6 months after LVRS in 21 consecutive patients (15 males, six females, mean (+/- S.E.) age: 62 +/- 1.9, range 42-74 years). All were former smokers and three had ZZ-AT1 deficiency. The inclusion criteria were: (a) severe bronchial obstruction (FEV1 < 35% predicted); (b) pulmonary hyperinflation (RV/TLC > 0.60); and (c) absence of hypercapnia (PaCO2 < 50 mmHg). RESULTS: The FEV1 had increased from 28 +/- 2% to 35 +/- 3% of the predicted value (P < 0.05) 6 months after surgery. The RV/TLC had declined from 0.65 +/- 0.02 to 0.55 +/- 0.02; PaO2 increased (66 +/- 1 versus 71 +/- 2 mmHg, P = 0.04), PaCO2 (38 +/- 2 versus 36 +/- 1 mmHg, P = 0.26) did not change. The pulmonary artery mean pressure (PAPmean) remained unchanged (18 +/- 1 versus 19 +/- 1 mmHg, P = 0.26). In six patients PAPmean was > or = 20 mmHg (up to 24 mmHg) preoperatively. After 6 months, six patients had a PAPmean > or = 20 mmHg (up to 31 mmHg). CONCLUSIONS: In patients with severe emphysema who are candidates for LVRS (but have only mild to moderate hypoxemia and a PaCO2 < 50 mmHg) we found no relevant pulmonary hypertension and pulmonary artery pressure did not change significantly after surgery. Therefore, routine right heart catheterization is not mandatory for preoperative evaluation.

Adult↗
PubMed1998

Effect of a short period of warm ischemia after cold preservation on reperfusion injury in lung allotransplantation.

OBJECTIVE: A short period of warm ischemia during lung allograft implantation is inevitable. We studied the effect of 2 h of warm ischemia before implantation after 18 h of cold preservation on reperfusion edema and pulmonary hemodynamics in a large animal model. METHODS: Left lung transplantation was performed in ten weight-matched pigs (25-31 kg). Donor lungs were flushed with 1.5 l cold (1 degree C) LPD solution and preserved for 20 h. In Group I (n = 5) the grafts were preserved for 20 h at 1 degree C and topically cooled with ice slush during implantation until reperfusion. In Group II (n = 5) lungs were stored at 1 degree C for 18 h followed by 2 h preservation at room temperature (20 degrees C). Topical cooling was not used during implantation. At 1 h after reperfusion the recipient contralateral right pulmonary artery and bronchus were ligated to assess graft function only. Extravascular lung water index (EVLWI), intrathoracic blood volume (ITBV), mean pulmonary artery pressure (PAP) and cardiac output (CO) were assessed during a 4 h observation period. Quantitative myeloperoxidase (MPO) activity and thiobarbituric acid-reactive substance (TBARS) levels as an indicator for lipid peroxidation were determined in allograft tissue samples taken 5 h after reperfusion. RESULTS: In Group II a tendency to improved pulmonary vascular resistance and cardiac output was noted. Surprisingly, lung edema, assessed by EVLWI, did not increase in animals with warm ischemia. Even a tendency to a reduced EVLWI was noted. However, differences between groups did not reach statistical significance. Gas exchange did not differ statistically significant between groups. CONCLUSION: Our results indicate that a short period of warm ischemia before reperfusion does not lead to increased pulmonary edema. In animals with a short period of warm ischemia before reperfusion, even a tendency to reduced posttransplant lung reperfusion injury was noted. In this model, topical graft cooling during lung implantation did not improve posttransplant graft function.

Animals↗
PubMed1998

Accidental pleural puncture by a thoracic epidural catheter.

We report the occurrence of an accidental pleural puncture by an epidural catheter that happened during the attempted induction of thoracic epidural anaesthesia using a paramedian approach in an awake patient. The incorrect placement of the catheter was recognised while the patient was undergoing thoracoscopic surgery. The possibility of accidental pleural puncture during attempted thoracic epidural catheter placement by either the paramedian or the midline approach should be borne in mind. A misplaced catheter may injure lung tissue and result in a potentially dangerous intra-operative tension pneumothorax.

Aged↗
PubMed1998

Exercise performance and gas exchange after bilateral video-assisted thoracoscopic lung volume reduction for severe emphysema.

Lung volume reduction surgery (LVRS) improves dyspnoea and pulmonary function in selected patients with severe emphysema. The purpose of this study was to assess the effects of LVRS on exercise performance and gas exchange in relation to changes in pulmonary function. In 40 patients (63.2+/-1.4 yrs, mean+/-SE) with severe emphysema (forced expiratory volume in one second (FEV1) 29+/-1% predicted, residual volume/total lung capacity (RV/TLC) ratio: 0.63+/-0.01) we assessed dyspnoea, pulmonary function and exercise performance before and 3 months after bilateral video-assisted thoracoscopic LVRS. The Medical Research Council dyspnoea score fell from 3.5+/-0.1 to 1.4+/-0.1 (p<0.0005); FEV1 increased by 55+/-9% to 44+/-2% pred (p<0.0005), RV/TLC decreased from 0.63+/-0.01 to 0.51+/-0.02 (p<0.0005). The diffusing capacity remained unchanged. Maximal work load during bicycle ergometry increased from 34.3+/-2.0 to 48.9+/-2.4 W (p< 0.0005), maximal oxygen uptake (V'O2max) from 10.0+/-0.4 to 12.8+/-0.3 mL x kg(-1) x min(-1) (p<0.0005). The increase in maximal ventilation during exercise (V'Emax) from 29.5+/-1.5 to 38.6+/-1.8 L x min(-1) (p<0.0005) was associated with increases in tidal volumes at isowatt and maximal exercise while corresponding breathing frequencies remained unaltered. The increases in V'O2max and V'Emax correlated with the increases in FEV1 and the decreases in RV/TLC. We conclude that the improvement in pulmonary hyperinflation and airflow obstruction after bilateral thoracoscopic lung volume reduction surgery may reduce ventilatory limitation, thereby increasing exercise capacity.

Adult↗
PubMed1998

[Functional results after bilateral thoracoscopic lung volume reduction surgery in emphysema].

We investigated functional results, complications and survival of patients undergoing bilateral video-assisted thoracoscopic (VAT) lung volume reduction surgery (VRS) for severe, diffuse pulmonary emphysema [FEV1 28 +/- 0.8 (% pred.), RV/TLC 0.65 +/- 0.01, 12' walking distance 499 +/- 21 (m)]. From January 1994 to March 1998, 106 of 286 candidates were operated, 85 patients (mean age 64, range 38-78 years, 30 females) fulfilled the study criteria and were included in the prospective study. Hyperinflation decreased to an RV/TLC ratio of 0.51 +/- 0.01 after 3 months and 0.55 +/- 0.02 after 24 months, FEV1 increased to 43 +/- 1.6 (% pred.) after 3 months and 35 +/- 2.3 (% pred.) after 24 months, and the 12' walking distance was 687 +/- 29 (m) 3 months postoperative and 626 +/- 44 (m) after 24 months.

Adult↗
PubMed1998

[Detection of unexpected extrathoracic metastases in preoperative staging of non-small-cell bronchial carcinoma (NSCLC) with positron emission tomography (PET)].

Accurate staging of non-small cell lung cancer (NSCLC) is essential for subsequent treatment. This study was designed to evaluate the value of FDG-PET in detecting unexpected extrathoracic metastases (ETM) in patients with NSCLC qualifying for surgical treatment based on conventional staging. One hundred patients with stage IIIa or less were included and underwent clinical evaluation, chest and upper abdominal CT scan, mediastinoscopy, and routine laboratory tests. If clinical signs of EM were present additional diagnostic methods, were applied. A partial body FDG-PET was performed. All findings in the FDG-PET were confirmed histologically or radiologically. Unknown ETM were detected in 13 patients (14%) at 19 sites. Whole-body FDG-PET improves detection of unsuspected ETM in patients with NSCLC otherwise eligible for surgery. Fourteen percent of patients were understaged.

Blood Glucose↗
PubMed1997

Salvage therapy with mycophenolate mofetil for lung transplant bronchiolitis obliterans: importance of dosage.

BACKGROUND: Bronchiolitis obliterans (BO) is the most important long-term complication of lung transplantation. Treatment of this condition is often unsuccessful. METHODS: A patient presented with early BO. Despite OKT3 and the addition of methotrexate, the patient needed persistently high doses of prednisone to maintain lung function at a moderate level. Only the substitution of azathioprine by mycophenolate mofetil (MMF, 3 g/day) made it possible to reduce the dose of prednisone. RESULTS: Reduction of the dose of MMF to 2 g/day resulted in a deterioration of lung function, which improved impressively after MMF was increased again to 3 g/day. CONCLUSIONS: MMF may be a valuable therapy for lung transplant BO. However, the use of a high dose, i.e., 3 g/day, may be crucial.

Adult↗
PubMed1997

[Lung transplantation].

Over the last years lung-transplantation has evolved into an effective therapy for patients with end-stage disease pulmonary parenchyma or vessels. The main indications for lung-transplantation are pulmonary emphysema, cystic fibrosis, idiopathic pulmonary fibrosis or pulmonary hypertension. All diseases associated with chronic infections such as cystic fibrosis or bilateral bronchiectasis need a bilateral lung-transplantation. In addition we transplant bilaterally all patients with pulmonary hypertension and young patients with pulmonary emphysema. In all other cases, a unilateral lung-transplantation is the treatment of choice. Heart-lung-transplantation is generally applied in patients with Eisenmenger-syndrome. At the time of transplantation patients suffer from dyspnea NY-HA III-IV and are mostly oxygen dependent. Life expectancy is limited to 6 to 18 months. Over the last years nearly 5000 lung-transplantations were performed worldwide. Survival rate after 1 year was 70 to 90% and 60 to 70% after 3 years respectively. In Switzerland there were approximately 80 lung-transplants performed since 1992 with a one year survival rate of approximately 75%.

Adult↗
PubMed1997

Radiologic emphysema morphology is associated with outcome after surgical lung volume reduction.

BACKGROUND: Lung volume reduction surgery is known to alleviate dyspnea and to improve pulmonary function, performance in daily activity, and quality of life in selected patients with severe pulmonary emphysema. We investigated the role of radiologically assessed emphysema morphology on functional outcome after a lung volume reduction operation. METHODS: The preoperative chest computed tomograms in 50 consecutive patients who had undergone surgical lung volume reduction were retrospectively reviewed by 6 physicians blinded to the clinical outcome. Emphysema morphology was determined according to a simplified classification (ie, homogeneous, moderately heterogeneous, and markedly heterogeneous; lobe predominance). We studied the impact of these morphologic aspects on functional outcome at 3 months. RESULTS: We found a fair interobserver agreement applying our classification system. Functional improvement after surgical lung volume reduction was best in markedly heterogeneous emphysema with an increase in forced expiratory volume in 1 second of 81% +/- 17% (mean +/- standard error, n = 17) compared with 44% +/- 10% (n = 16) for intermediately heterogeneous emphysema. But also in patients with homogeneous emphysema clinical relevant improvement of function could be observed (increase in forced expiratory volume in 1 second = 34% +/- 6%; n = 17). CONCLUSIONS: The morphologic type of emphysema, assessed by a simplified surgically oriented classification, is an important predictor of surgical outcome. Lung volume reduction surgery may also improve dyspnea and lung function in homogeneous emphysema.

Adult↗
PubMed1997

Thoracoscopic bilateral lung volume reduction for diffuse pulmonary emphysema.

OBJECTIVE: In a prospective study, we investigated the functional results, complications and survival of bilateral video-assisted thoracoscopic (VAT) lung volume reduction (LVR) in a selected group of patients with severe, nonbullous pulmonary emphysema. From January 1994 to September 1996, 42 of 143 candidates (13 female, 29 male, 42-78 years) were operated. They were short of breath on minimal exertion due to severe airflow obstruction and hyperinflation (FEV1 < 30%) pred., TLC > 130% pred., RV > 200% pred.). METHODS: LVR was performed bilaterally by VAT using endoscopic staplers without buttressing the staple lines. Pulmonary function test (PFT), MRC dyspnea score and 12 min walking distance were assessed preoperatively, at 3, 6 and 12 months. In addition lung function was measured at hospital discharge. RESULTS: The patients reported a marked relief of dyspnea, which persisted at all follow-up visits (P<0.001). FEV1 increased from 0.80 +/- 0.24 (L) to 1.14 +/- 0.41 (L) postoperatively, a 43% gain (P < 0.001). A relevant increase of FEV1 persisted for at least 1 year. The residual volume to total lung capacity ratio decreased from 0.64 to 0.56 at hospital discharge. The mean 12 min walking distance increased from 500 +/- 195 (m) to 770 +/- 222 (m) after 1 year (P < 0.001). The mean hospital stay was 13 +/- 5.5 days (median 12.0), drainage time was 9 +/- 4.3 (median 8.0) days. There was no 30 day mortality. Three patients died between 2 and 15 months postoperatively by non surgery related reasons. One patient underwent lung transplantation 5 months after surgical lung volume reduction. CONCLUSIONS: In a selected group of patients with severe, nonbullous pulmonary emphysema, bilateral LVR by VAT results in instantaneous postoperative improvement in pulmonary function and dyspnea. These favorable effects, including an amelioriation in exercise performance, lasted for at least 1 year.

Adult↗
PubMed1997

VATS resection of an oesophageal leiomyoma in a patient with neurofibromatosis Recklinghausen.

A series of reports in the literature suggest an association of neurofibromatosis Recklinghausen with intestinal tumors as carcinoids, leiomyomas and leiomyosarcomas. We present a case of a 23-year-old man with severe cutaneous manifestation of neurofibromatosis. Dysphagia was the main symptom. CT scan suggested the diagnosis of an oesophageal leiomyoma. The oesophageal muscle layers were split and the tumor was enucleated by video assisted thoracoscopic surgery (VATS). The postoperative course was uneventful. The patient was drinking liquids from day 1 and was eating a normal diet from day 3 postoperatively. He was dismissed from the hospital on the 4th postoperative day. We conclude that in patients with neurofibromatosis and oesophageal symptoms an intestinal manifestation of the disease in the oesophagus has to be considered and that VATS resection of intramural and extrinsic oesophageal leiomyomas is the treatment of choice.

Adult↗