Search PubMed⌕ Search

Biomedical subjects

C T Bolliger

Publications and source records attributed to C T Bolliger.

At least 19 recordsLinked to original sources
PubMed1995

[Combination endobronchial and conventional therapy possibilities in inoperable central lung tumors].

Up to 85% of patients with bronchogenic carcinoma are inoperable at the time of diagnosis and treatment remains largely palliative. Prognosis depends on the clinical tumor stage. In non-small cell carcinoma the clinical stages (I-IV) are defined according to the TNM classification, whereas in small cell carcinoma limited disease is distinguished from extensive disease. Neither classification accurately takes endobronchial tumor spread into account. At the time of diagnosis up to 30% of all lung cancer patients present with central airway obstruction and clinical signs of dyspnea, atelectasis and pneumonia. Most patients with central airway stenosis have inoperable tumors (stage IIIb and IV) and have until recently undergone conventional treatment consisting exclusively of chemo- and radiotherapy. Currently the best results are obtained with combined chemoradiotherapy. The rapid developments in the area of endobronchial treatment modalities enable us to relieve bronchial obstructions fast and safely. This achieves immediate symptomatic relief which in many cases is a precondition for starting chemo- or radiotherapy. Successful reopening of a major airway helps to prolong local tumor control and thus survival. Patients with inoperable lung cancer and obstruction of central airways should undergo initial endobronchial therapy followed by conventional chemo-radiotherapy.

Antineoplastic Agents↗
PubMed1995

Exercise capacity as a predictor of postoperative complications in lung resection candidates.

Exercise testing with measurement of maximal oxygen uptake (VO2max) is increasingly used in the assessment of lung resection candidates, but its predictive value for postoperative complications remains controversial. We therefore sought to determine the prognostic value of VO2max compared with other pulmonary function tests. A consecutive group of 80 patients (mean age 61 yr; 57 males and 23 females) scheduled for lung resection (62 malignancies, 12 benign disorders, and 6 carcinoids) underwent pulmonary function tests and symptom-limited cycle ergometry. All patients underwent lung resections: 21 pneumonectomies, 45 lobectomies, and 14 segmental or wedge resections. Group A (64 patients, 80%) had an uneventful postoperative course, whereas Group B (16 patients, 20%) had complications; 3 of them died (4% overall mortality rate). In a stepwise logistic regression analysis used to determine independent risk factors for postoperative complications (within 30 d), VO2max expressed as a percentage of predicted (84 +/- 19 for Group A versus 61 +/- 11 for Group B) proved to be the best predictor (predictive value 85.5%). Although VO2max expressed in absolute values (ml/kg/min) was also highly predictive (79.5%), a ROC curve analysis proved the percentage predicted values to be significantly more sensitive. Of 9 patients with a VO2max < 60% of predicted, 8 had complications, including all 3 patients who died after resections of more than one lobe (sensitivity 50%, specificity 98%). The estimated probability (probit model SAS software package) of suffering no complication was 0.9 for VO2max > 75% of predicted and 0.1 for a VO2max < 43%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Lung scanning and exercise testing for the prediction of postoperative performance in lung resection candidates at increased risk for complications.

OBJECTIVE: To analyze the value of preoperative lung scanning and exercise testing for the prediction of postoperative complications and of the short- as well as long-term performance in lung resection candidates at increased risk for complications. DESIGN: Prospective clinical trial. SETTING: Clinical pulmonary function laboratory in a university teaching hospital. PATIENTS: Twenty-five (mean age, 63 years; 17 men) of 84 consecutive lung resection candidates were considered at increased risk for postoperative complications due to impaired pulmonary function (FEV1 < 2 L or diffusion of carbon monoxide [DCO] < 50% predicted, or FEV1 and DCO < or = 80% predicted combined with New York Heart Association dyspnea index > or = 2). INTERVENTIONS: Candidates underwent radionuclide ventilation/perfusion scans and exercise testing to predict postoperative (= ppo) values for FEV1, DCO, and maximal O2 uptake (VO2max). They all underwent thoracotomy for neoplastic lesions; 7 had pneumonectomies, 18 lobectomies. Six patients had postoperative complications (within 30 days), of whom three died. Three and 6 months postoperatively, pulmonary function tests and VO2max were repeated. MEASUREMENTS AND RESULTS: In the 22 survivors, the observed values were then compared with the predicted values. At 3 months, there were excellent correlations (absolute/predicted values): for FEV1 r = 0.78 and 0.81; for DCO, r = 0.77 and 0.74; and for VO2max, r = 0.71 and 0.83. The means of FEV1 and VO2max did not differ from the predicted values, whereas the predicted DCO was lower than the observed value (mL/min/mm Hg: 15.1 vs 17.9; percent predicted: 59.6 vs 70.9) (p < 0.05). At 6 months, correlations remained very good for FEV1 (r = 0.81 and 0.84) and for DCO (r = 0.76 and 0.74), but had decreased for VO2max to 0.56 and 0.65, respectively. All means were higher than predicted (p < 0.05) owing to recovery in the lobectomy group. Patients with postoperative complications (group B) had a lower preoperative VO2max in percent predicted (62.8 +/- 7.5% vs 84.6 +/- 19.7%) (p < 0.01) and also a lower VO2max-ppo (10.6 +/- 3.6 vs 14.8 +/- 3.5 mL/kg/min and 44.3 +/- 13.5 vs 68.0 +/- 20.7% predicted) (p < 0.05) than patients without complications (group A). A VO2max-ppo < 10 mL/kg/min was associated with a 100% mortality. Although FEV1-ppo and DCO-ppo were lower in group B, the difference did not reach significance. CONCLUSIONS: Radionuclide-based calculations of postoperative VO2max are predictive of operative morbidity and mortality: a VO2max-ppo of < 10 mL/kg/min may indicate inoperability. Further, short-term postoperative performance is accurately predicted by FEV1-ppo and VO2max-ppo, but long-term function is underestimated after lobectomy.

Aged↗
PubMed1995

[Strategy for staging non-small cell bronchial carcinoma (NSCLC) with special reference to imaging procedures].

Imaging methods, especially CT and for specific questions MRI, are an essential part of diagnosis and staging of non-small cell lung cancer. They are effective methods for the detection of unresectable tumours and avoid the necessity for further invasive examinations and explorative thoracotomies. The judgement of lymph node size by CT suffers from a limited accuracy. Nevertheless, it allows guided bronchoscopical staging biopsies of enlarged mediastinal lymph nodes (> 1 cm) and, therefore, a selective indication of mediastinoscopy. CT scans of the thorax usually are extended to the adrenal glands and the liver to exclude metastasis. Extrathoracic scanning beyond the upper abdomen and bone scintigraphy should be restricted to patients with clinical indicators or symptoms. The combined application of imaging methods, bronchoscopy, and mediastinoscopy provides better selection of surgical candidates and hence reduces the rate of unresectable operations.

Bronchoscopy↗
PubMed1994

[Interventional bronchoscopy].

The field of bronchoscopy has considerably expanded in recent years. The rigid and flexible bronchoscope are both used for diagnostic and increasingly for therapeutic procedures; for the therapeutic procedures the term 'interventional bronchoscopy' has been coined. Apart from the more traditional indications for interventional bronchoscopies, such as aspiration of secretions and removal of foreign bodies, the treatment of inoperable stenoses of the central airways--benign or malignant--has moved to the center stage of interventional endoscopies. This review focuses on the technique and indication of the following procedures: bronchial toilette, foreign body removal, dilatation, diathermy, cryotherapy, photodynamic therapy, laser resection, brachytherapy and the insertion of stents (endoprostheses).

Airway Obstruction↗
PubMed1994

Evaluation of high-risk lung resection candidates: pulmonary haemodynamics versus exercise testing. A series of five patients.

We compared the value of exercise testing and measurement of pulmonary haemodynamics (PH) in the pre-operative assessment of 5 patients (mean age: 64 years, 3 men) with clinical stage I or II bronchogenic carcinoma and severe chronic obstructive pulmonary disease. They were considered at high risk due to poor pulmonary function tests (PFT); (one or more of the following): (1) radionuclide calculated postlobectomy FEV1 < 30% predicted, (2) diffusion capacity or transfer factor < 60% predicted, combined with a fall in PaO2 on maximal exercise of > 5 mm Hg, (3) a PaCO2 at rest of > 45 mm Hg. Maximal oxygen uptake (VO2max) during symptom-limited cycle ergometry and PH were measured in these 5 patients. They were considered eligible for lobectomy if they fulfilled at least one of the two criteria: (1) mean pulmonary artery pressure (PAP) of < 35 mm Hg and pulmonary vascular resistance of < 190 dyn.s.cm-5 at moderate exercise (40 W), (2) a VO2max of > or = 15 ml/kg/min. Six months postoperatively PFT and VO2max were measured again. PAP40W was 21, 38, 38, 46 and 52 mm Hg, respectively, which would have excluded 4/5 patients from surgery. VO2max was 21.7, 14.9, 13.4, 19.2 and 18.6 ml/kg/min, respectively, which would have excluded 2/5 patients. Expressed in percent predicted, however, VO2max was > or = 69% in all 5 patients, indicating only mild impairment of exercise capacity in the 2 patients with < 15 ml/kg/min VO2max. Therefore all 5 patients were offered surgery and underwent lobectomy. Apart from 1 prolonged air leak no complications occurred, the mean hospital stay was 16 days (13-21).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Special endobronchial palliative measures].

Inoperable pulmonary malignancies can present with local stenoses of the central airways either at the time of diagnosis or later on. Depending on their localization, these obstructions cause progressive dyspnea, postobstructive atelectasis and/or pneumonia. The patient's general condition will deteriorate, and at the tracheal level life-threatening dyspnea can develop. If central airways stenosis is suspected, fiberbronchoscopy is mandatory to decide whether local endobronchial palliation is a feasible treatment modality. Usually, local palliation is combined with chemo-and/or radiotherapy. Laser resection using the Nd-YAG laser is performed for obstructions caused by endoluminal tumour growth and leads to an immediate effect after a single session. Brachytherapy means local, endobronchial irradiation with a short depth of penetration. The active probe is placed with the aid of the fiberbronchoscope. Brachytherapy can be used alone, but is often combined with an initial laser resection for the consolidation of the treatment effect. The principal of photodynamic therapy consists of photosensitization of tumour cells followed by local laser light application which leads to cell death. In selected cases this treatment can be curative. Extrinsic stenoses which are caused by external compression of the airways or by thickening of the airway walls through submucosal tumour spread must be treated by dilatation and insertion of stents (endoprostheses) to maintain airway patency. These stents--mostly self-expanding silicone or metal devices--are usually inserted with the rigid bronchoscope. Again, endobronchial and/or percutaneous radiotherapy is added to obtain longer local tumour control.

Airway Obstruction↗
PubMed1994

Bronchoprotection by salmeterol: cell stabilization or functional antagonism? Comparative effects on histamine- and AMP-induced bronchoconstriction.

Salmeterol provides bronchoprotection against a number of constrictor stimuli for more than 12 h after a single dose. This effect could be due either to functional antagonism at the level of airway smooth muscle or to cell-stabilizing effects of the compound. In this study, we attempted to clarify this mechanism by comparing the effects of salmeterol (50 micrograms), salbutamol (200 micrograms) and placebo on the airway responsiveness to histamine (to assess functional antagonism), and to adenosine 5'-monophosphate (AMP) (to assess additional cell-stabilizing effects), 14 h after drug treatment. Thirteen patients with mild allergic asthma were studied in a double-blind, randomized protocol on 6 days, at least 48 h apart. Forced expiratory volume in one second (FEV1) was measured before and 15 min after inhalation of the study medication. Then, 14 h later (8 a.m. the following morning), a bronchoprovocation test with histamine or AMP was performed. We found that 14 h after inhalation, salmeterol still had a significant effect on FEV1 in comparison to placebo and salbutamol. The provocative dose producing a 20% fall in FEV1 (PD20histamine) was significantly increased after salmeterol, whilst the increase in PD20AMP did not reach significance. The shift in PD20 (in doubling dose steps) induced by salmeterol pretreatment was not different between histamine and AMP. We conclude that the prolonged protective effect of salmeterol occurs via an extended bronchodilating and functional antagonistic action and not via a cell-stabilizing effect.

Adenosine Monophosphate↗
PubMed1994

Pulmonary oedema and hypotension induced by hydrochlorothiazide.

We present the case of a patient with acute onset of dyspnoea after a long-distance flight. Pulmonary embolism was suspected, but could be excluded by perfusion scintigraphy. The electrocardiogram and chest X-ray were compatible with acute myocardial infarction and pulmonary oedema, but the slightness of the elevation of pulmonary capillary wedge pressure allowed cardiogenic pulmonary oedema to be excluded. The clinical picture was then interpreted as pneumonia with sepsis and hypotension. The rapid and full clinical recovery within 48 h, together with the close temporal relationship of ingestion of hydrochlorothiazide and the onset of symptoms, allowed the diagnosis of drug-induced pulmonary oedema and anaphylactoid hypotension.

Anaphylaxis↗
PubMed1993

[Severe hemoptysis in pulmonary vasculitis].

A 27-year-old man, in good health but a moderate smoker, suddenly had two episodes of haemoptysis. Routine clinical examination was unremarkable. Erythrocyte sedimentation rate was increased to 34 mm/h. The chest radiography showed ill-defined, contrast-poor infiltrations bilaterally, as well as left hilar enlargement. Lung scintigraphy and pulmonary arteriogram suggested pulmonary embolism, possible from a "pelvic vein spur", i.e. an intimal proliferation due to crossing of the common iliac artery over the pelvic vein. He was placed on oral anticoagulants. Three months later he had another severe haemoptysis, providing the indication for an exploratory thoracotomy. This revealed the left pulmonary artery wall to have inflammatory changes with aneurysmal dilatation. The aneurysm was plicated. Histological examination demonstrated chronic vasculitis as seen in Behçet's syndrome, a diagnosis confirmed by the findings of ulcers of the oral mucosa and the presence of HLA B5 allo-antigens. Immunosuppressive treatment was given with prednisone (1 mg/kg), azathioprine (2.5 mg/kg) and ciclosporin (5 mg/kg). Over the next 12 months there has been only one further haemoptysis.

Adult↗
PubMed1993

The flow-volume loop in bilateral vocal cord paralysis.

A 38-year-old man with posttraumatic bilateral vocal cord paralysis and a surgically repaired avulsion of the extrathoracic trachea presented with a slight increase of exertional dyspnea (grade 2). Spirometry showed high normal FEV1 for FVC variables, but the F-V loop was characteristic for highly variable UAO with an increased FEV1/PEF ratio of 11 ml/L/min as well as a MEF50/MIF50 of 4.55. Endoscopy during forced respiration showed near total inspiratory obstruction of the larynx due to paradoxical behavior of the vocal cords. In extrathoracic airway obstruction a FEV1/PEF ratio > 10 ml/L/min combined with a MEF50/MIF50 ratio > 4 is suggestive of variable UAO caused by bilateral vocal cord paralysis rather than by a tracheal lesion.

Adult↗
PubMed1993

Silicone stents in the management of inoperable tracheobronchial stenoses. Indications and limitations.

BACKGROUND: Various stent models have been developed for the treatment of inoperable stenoses of the central airways caused by external compression. Increasing use is made of the silicone stents designed by Dumon. We tested their technical feasibility, tolerance, and long-term efficacy in relieving respiratory symptoms in patients referred for endoscopic palliation of malignant disease. METHODS: All procedures were performed under general anesthesia with the use of the rigid bronchoscope. We inserted 38 stents in 31 patients (median age, 67 years; 25 men and 6 women) whose airways showed residual obstruction of > 50 percent of the lumen after laser resection of endobronchial tumor and/or mechanical dilatation of extrinsic compressions. RESULTS: Stent placement and removal--where necessary--were easy in all patients, but five stents inserted in three patients with short (< or = 2.5 cm) and conical stenoses migrated, necessitating emergency removal. In 27 of the remaining 28 patients, stent tolerance was excellent; 1 proximal tracheal stent (< 1 cm below the vocal cords) had to be removed because of otalgia and dysphagia. One lethal hemoptysis occurred within hours after a repeated laser therapy and removal of an indwelling stent. No other serious complications occurred. Immediate and lasting relief of dyspnea and improvement in performance status (Karnofsky scale, activity index) was achieved in 90 percent (28/31) of patients (p < 0.01). The influence of adjuvant radiotherapy on local tumor recurrence and survival was analyzed in a subgroup of ten patients with stage IIIB squamous cell carcinoma with comparable performance status. Five did not undergo adjuvant radiotherapy (group A) and five did (group B). In group A, four of five stents were occluded by tumor recurrence above or below the stent after a median follow-up of 2 months; in group B, zero of five were occluded (p < 0.05) after 4 months. Median survival was 4 months in group A and 6 months in group B; the difference did not reach significance. CONCLUSIONS: The silicone stents designed by Dumon are easily inserted and removed; they are also well tolerated and very efficacious in relieving respiratory symptoms caused by extrinsic airway compression. Short and conical stenoses present limitations for their use due to increased risk of migration. Combined treatment with laser resection, stent insertion, and subsequent radiotherapy is necessary to prevent local tumor recurrence and may improve survival.

Adult↗
PubMed1992

[Acute severe asthma: emergency diagnostic and therapeutic measures].

There is growing evidence that the prevalence and the severity of bronchial asthma are rising in the industrialized countries despite a marked increase in the sale of antiasthmatic drugs. Non-diagnosis and undertreatment of patients with asthma may be causative factors. Identification of acute severe asthma by the physician and early hospitalization of patients at risk are important factors in lowering morbidity and mortality. Indicators of severe asthma on initial assessment are a history of poor long-term control (previous hospital admissions, regular use of inhaled beta agonists, maintenance oral corticosteroid treatment, prolonged current attack and low or greatly varying peak flow values) and clinical examination with spirometry as the most objective tool. A peak expiratory flow (PEF) of < 30% pred. (< 100-120 l/min) and a forced expiratory volume in the first second (FEV1) of < 25% pred. (< 0.7-1.01) indicate severe asthma. The physical signs and symptoms correlate well with the spirometric values but show too much variability to be used alone. A PaCO2 value of > or = 45 mm Hg (6 kPa) is very specific for severe asthma. Patients whose asthma is considered severe on initial assessment must be referred to a hospital. In the emergency ward the documented response to treatment, i.e. the speed of recovery, is the most important parameter for discharge or admission to hospital. Only patients who improve within a few hours, who remain clinically stable and who have a PEF > 75% pred. or an FEV1 > 50% pred. should be discharged.

Acute Disease↗
PubMed1992

[Palliative measures in tumor-induced obstruction of the airways].

Local stenoses of the central airways in malignant inoperable disease are sometimes present at the time of diagnosis or develop over time after the completion of systemic palliative treatment. These stenoses should be relieved by local means in order to prevent the development of atelectasis and poststenotic pneumonia. Otherwise, patients will develop progressive dyspnea, and their general condition will decline rapidly. Various methods aimed at the relief of local obstructions exist and are often used in combination. Most procedures are performed under general anaesthesia using the rigid bronchoscope. Intraluminal obstructions can be relieved by laser-, cryo- and brachytherapy (endobronchial radiation). Extrinsic stenoses caused by airway compression from outside or by thickening of the airway wall through submucosal tumor growth must be dilated. At the end of these procedures, the insertion of silicone stents is ideally suited to maintain airway patency in dilated extrinsic stenoses and to prevent recurrent intraluminal tumor growth after laser therapy. The various methods aimed at the relief of malignant local airway obstructions are discussed, with emphasis on the recently developed silicone stents.

Airway Obstruction↗
PubMed1992

Pulmonary artery compliance: its role in right ventricular-arterial coupling.

OBJECTIVE: The aim was to investigate the ventricular/vascular coupling of the intact right heart under conditions of normal operation and acute pulmonary hypertension. METHODS: Right ventricular contractility was obtained by calculating the end systolic pressure-volume relationship (Ees) and the effective pulmonary arterial elastance (Ea), applying the Windkessel parameters of the pulmonary arterial input impedance. Coupling between the ventricle and its load could be determined in terms of Ees and Ea. Acute pulmonary hypertension was induced by injecting glass microspheres into the pulmonary vascular bed until a mean pulmonary arterial pressure of more than 35 mm Hg had been reached. Experimental subjects were Landras/Large white pigs (n = 11), studied under general anaesthesia. Ees was obtained by normalising the right ventricle pressure-diameter equivalent of Ees to stroke volume. The lumped element parameters of the Windkessel analogue were calculated from the pulmonary artery pressure and blood flow. Stroke work was calculated from the pressure-volume loop and oxygen consumption derived from the pressure-volume area. Efficiency was taken to be the ratio between stroke work and oxygen consumption. RESULTS: Ea increased significantly as mean pulmonary artery pressure rose, while Ees remained linear and constant. Stroke work, as well as efficiency, increased, with the maximum of the stroke work curve lying to the right of the efficiency maximum. At the control step (before pulmonary artery hypertension), Ees = 1.71 Ea (n = 11). CONCLUSIONS: Under control conditions, the right ventricle operates at maximum efficiency and submaximal work output. Compliance of the pulmonary artery is a significant factor in decoupling the right ventricle from its vascular load. As the compliance decreases with acute pulmonary hypertension, the maximum stroke work against load point shifted in such a manner that the right ventricle changed its operational status from a flow to a pressure pump, resulting in a decreased stroke volume.

Acute Disease↗