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Biomedical subjects

L Freitag

Publications and source records attributed to L Freitag.

At least 19 recordsLinked to original sources
PubMed1999

Trimodality therapy in stage III non-small cell lung cancer: prediction of recurrence by assessment of p185neu.

In a trimodality treatment approach for stage III non-small cell lung cancer the prognostic impact of pretherapeutic p185neu assessment was evaluated. Fifty-four patients were admitted to chemotherapy followed by twice-daily radiation with concomittant low-dose chemotherapy and subsequent surgery. Immunohistochemical assessment of p185neu expression was performed in paraffin-embedded mediastinal lymph node metastases, by mediastinoscopy biopsy prior to therapy. Paraffin-embedded biopsies of mediastinal lymph node metastases were available in 33 cases. Seven out of eight patients with positive p185neu staining developed distant metastases, in contrast to seven out of 25 negative cases. Expression of p185neu in mediastinal lymph node metastases was a significant predictor for progression-free survival (p=0.047) and resulted mainly from significant differences in metastases-free survival (p185neu-positive versus p185neu-negative: median, 11 versus 19 months; 2- and 3-yr rates, 13% and 0% versus 40% and 32%; p=0.04). On the basis of these preliminary results it was concluded that further evaluation of p185neu expression in trials on neoadjuvant and adjuvant therapy is warranted. When the prognostic impact of p185neu in such trials with larger patient numbers is confirmed, this may contribute to the identification of stratification variables for future treatment approaches of non-small cell lung cancer.

Adult↗
PubMed1997

Clinical evaluation of a new bifurcated dynamic airway stent: a 5-year experience with 135 patients.

The Dynamic stent, a bifurcated airway prosthesis facilitating coughing, was clinically evaluated. The stents were inserted bronchoscopically in 135 patients (84 male, 51 female, age 12-90 years, mean 59 years) suffering from compression stenoses, strictures or malacias of the central airways, or tracheo-esophageal fistulas. Extrinsic compression from malignant and semi-malignant tumors was the leading indication for stenting (47.4%), followed by esophago-airway fistulas (22.2%) and post-intubation stenoses (14%). Stent insertion turned out to be very easy and could be performed without complications. The Dynamic stent was well tolerated and gave immediate relief of dyspnea in most cases. Follow-up data, three months after the last implantation revealed that at least 24 patients were still alive with a stent in place and free of complaints. In 27 cases, the stent had been removed after response to treatment. One of these patients received a second in order to seal a fistula, two months after removal of the first one. 85 patients, 79 with malignant, 6 with non-malignant diseases had died, with a mean survival time of 123 days (0 to 611 days). Complications directly attributable to the stent were rare. Two patients who had received the stent to counteract severe tracheal compression from aortic abnormalities died from arrosion and hemoptysis. There were no other severe complications. Cephalad migration occurred in 4/136 inserted stents. The Dynamic stent can be considered feasible, effective, and comparitively safe.

Adolescent↗
PubMed1996

Transsternal transpericardial operations in the treatment of bronchopleural fistulas after pneumonectomy.

Between 1972 and 1993, 19 patients (15 males and 4 females) with bronchopleural fistulae and pleural empyema after pneumonectomy were treated with transsternal transpericardial operations and closure of the fistula. The underlying malignant disease was a non-small cell carcinoma in 12, a malignant epithelial mesothelioma in two, and an atypical carcinoid tumor in one case. One patient each presented with tuberculosis, chest trauma, and lung destroyed by bronchiectasis. Fistulas affected the right bronchial stump in 17, and the left in 2, cases after pneumonectomy. The time between pneumonectomy and transsternal transpericardial operation ranged between 1 month and 4 years. All patients were submitted to drainage and irrigation of the empyema cavity (2-4 weeks). In 16 patients a long bronchial stump was sutured or stapled, in three cases resection of a short stump with the distal trachea was followed by anastomosis of the trachea and left main stem bronchus. Irrigation of the pneumonectomy cavity was continued in all patients for 2 weeks. Transsternal transpericardial operation was successful in 15 patients. Two patients died in the first 30 days, of renal or respiratory failure without fistula recurrence. In two cases the fistula recurred; definitive healing was achieved using a great omentum flap and endoscopic application of fibrin glue and bone spongiosa. Transsternal transpericardial management of bronchus stump fistula after pneumonectomy is highly effective and offers advantages over the direct approach through the infected empyema cavity.

Adult↗
PubMed1996

Respiratory failure due to tracheobronchomalacia.

A case is described of tracheobronchomegaly progressing to extensive tracheomalacia, complicated by episodic choking, recurrent pulmonary infections, and irreversible hypercapnic respiratory failure. A Y-shaped tracheobronchial stent was placed endoscopically to splint the trachea open, with excellent clinical and physiological improvement. New stent designs may provide long term palliation in selected cases of diffuse tracheal collapse or stenosis, and offer an alternative to surgical repair.

Airway Obstruction↗
PubMed1996

Management of malignant esophagotracheal fistulas with airway stenting and double stenting.

Prognosis of inoperable or recurrent esophageal carcinoma is, at best, poor. Once an esophagotracheal fistula has developed, the overall condition of the patient declines rapidly. Aspiration pneumonia and severe coughing are common. The introduction of esophageal tubes does not always seal the fistula sufficiently and may compromise the airway causing stridor and dyspnea. In 30 patients (25 male, 5 female; age 23 to 74 years; mean, 56 years) with very large fistulas and airway problems, we inserted an airway stent (Dynamic) (n = 12) or an esophageal tube combined with a Dynamic airway stent (n = 18) with the aim of sealing the fistula and restoring patency of the airway and GI passage. The tracheobronchial Dynamic stent was chosen because its slightly concave, flexible posterior silicone membrane adapts ideally to the convex esophageal tube. The stents were well tolerated and significantly improved the quality of life. Of 30 patients, 16 could breathe and swallow unimpaired until shortly before their death. Moderate complaints persisted in five patients, dysphagia in eight patients, and dyspnea in one patient. Mean survival time in the double stent group was significantly greater (110 days) than in the airway stent-only group (24 days) or comparable groups in the literature treated with esophageal tubes only. We conclude that carefully selected patients can benefit from double stenting of esophagus and airways.

Adult↗
PubMed1996

The role of brachytherapy in the treatment and control of central bronchial carcinoma.

Endobronchial brachytherapy is by far the oldest interventional bronchiological treatment procedure. In the decades following its inception in 1922, it has undergone progressive modification by innovations in radiation physics and techniques, and has enjoyed a renaissance with the introduction of fibreoptic bronchoscopy, local anaesthesia, modern afterloading devices, and high dose rate (HDR) treatment with iridium-192, an isotope with very high activity. However, there is little standardization of dose-specification, fractionation and optimal dosage using this isotope, and homogeneous, objective analyses of the clinical results of treatment using iridium-192 is lacking. Very often, the exact staging of patients is lacking. For such reasons, any evaluation of the efficacy of endobronchial brachytherapy is significantly impeded. However, reliable data are available on the palliative effect of HDR-brachytherapy, which is safe, fast in onset and apparently superior to external beam radiotherapy (EBRT) alone. In addition, some studies document the curative effects, or complications, offers not only an insight into the working principles of radiation treatment but also into the biological behaviour of bronchial tumours. Endobronchial HDR-brachytherapy should be compared to the other interventional procedures focusing on the same aim, namely that of restoring patency of a previously occluded bronchus. This is the overall challenge to pneumologists working in this field.

Brachytherapy↗
PubMed1996

[Experiences with fluorescence diagnosis and photodynamic therapy in a multimodality therapy concept of operated, recurrent bronchial carcinoma].

Even of those few patients who are operated because of bronchial cancer up to a quarter develop a recurrence. One reason is certainly that tumor-cells already present at the time of surgery are bronchoscopically invisible. Fluorescence methods might be able to detect these malignant cells. For patients with post-surgical recurrences the therapeutical choices are limited due to the loss of parenchyma. Photodynamic therapy (PDT) with the hematoporphyrine derivative Photofrin is one laborious but promising option. Based on an argon-dye laser we have developed a combined system for the diagnostical measurement of autofluorescence and Photofrin-induced fluorescence at 488 nm and the therapeutical PDT at 630 nm. Under the excitation with blue light from the argon laser, differences in the autofluorescence of malignant and benign cells can be distinguished. Following the injection of Photofrin a spectrum peak at 628 nm clearly delineates tumor cells. In six out of twelve patients with post-surgical recurrences a single PDT course resulted in tumor eradication. With additional PDT courses and brachytherapies local tumor control could be achieved in all cases. The general photosensitivity and the necessary light protection were tolerated by all patients. In order to avoid severer complications such as asphyxia, obstruction of bronchi and pneumotharaces resulting from fibrin-plugs and necrotic tissue following PDT must be considered. Especially in patients with pneumonectomy a careful surveillance and debridement is mandatory.

Aged↗
PubMed1995

[The dynamic trachea stent for treatment of benign and malignant tracheal obstruction].

Severe obstruction of the trachea is a life-threatening condition. In two patients with a benign cause of obstruction, women of 70 and 71 years old, and in one with a malignant cause, a man of 24 years old, insertion of a dynamic trachea stent led to instant relief of symptoms. The dynamic stent has the advantage over rigid or self-expanding stents that it does not migrate but may be easily removed, that it induces less granulation tissue, and that less mucus retention is seen, because it allows the normal cough mechanism to take place.

Adult↗
PubMed1995

Experimental models of tracheobronchial stenoses: a useful tool for evaluating airway stents.

BACKGROUND: Stent implantation is a conservative alternative to open operation for treating benign tracheobronchial strictures. Most of the presently available stents were primarily designed for endovascular use. Their respiratory use entails a risk of iatrogenic complications. From a scientific and from an ethical point of view these risks justify preclinical evaluation of new respiratory stents in experimental models of central airway stenoses. Therefore, an attempt was made to develop such models in piglets and adult minipigs. METHODS: Tracheal stenoses were obtained by creating first a segmental tracheomalacia through extramucosal resection of cartilaginous arches. The fibrous component of the stenoses was then obtained through bronchoscopic application of a caustic agent causing progressive deep mucosal and submucosal injury. Stenoses of the main bronchi were created by topical application of the caustic agent only. RESULTS: These models demonstrated the typical features of benign fibromalacic tracheobronchial stenoses with constant recurrence after mechanical dilation. Preliminary experiments showed that short-term problems of tolerance of stent prototypes are easily demonstrable in these models. CONCLUSIONS: These experimental models, which simulate quite realistically human diseases, offer the opportunity to perfect new tracheobronchial stents specifically designed for respiratory use and to evaluate their long-term tolerance before their use in humans.

Animals↗
PubMed1995

Tracheal carcinoma and mixed pneumoconiosis. A causal relationship?

We report on a 58-year-old man who had worked as a plumber and fitter for over 41 years and had been exposed to asbestos, man-made mineral fibers and welding fumes. Eighteen months before death, squamous cell carcinoma of the trachea occurred. Energy-dispersive X-ray analysis revealed intrapulmonal dust deposits in accordance with his exposure. A relationship between the tracheal carcinoma and the dust exposure causing a mixed pneumonoconiosis seems to be probable.

Asbestos↗
PubMed1994

Development of a new insertion technique and a new device for the placement of bifurcated airway stents.

We developed a new insertion technique and designed a forceps device for the placement of bifurcated airway stents; 131 of 142 endoscopically placed tracheobronchial Y-stents were inserted with a forceps and a laryngoscope. For the last 52 stent implantations we used the new stent forceps. It was determined to be a simple and safe method without major complications. In 11 cases alternative techniques had to be used. Technique and device are described in detail.

Bronchoscopy↗
PubMed1994

Omentopexy and muscle transposition: two alternative methods in the treatment of pleural empyema and mediastinitis.

From March 1987 to March 1993, 64 patients with chronic empyema and mediastinitis were treated with omentum and thoracic muscle transposition. There were 36 male and 28 female patients, age range 29 to 76 years. 31 patients suffered from chronic empyema and bronchopleural fistula after lung surgery, 18 patients had chronic empyema after pulmonary inflammatory disease, and 15 patients developed a mediastinitis with or without pleural empyema after cardiac surgery or irradiation of the chest wall. The pedicled omentum was used in 33, the thoracic muscles latissimus dorsi, pectoralis major, serratus anterior, and trapezius either alone or combined in 31 cases. There were no perioperative deaths. Bronchopleural fistulas and infected spaces were successfully closed in 61 patients (95.3%). Postoperative CT scan, angiography, bronchoscopy, and lung function tests demonstrate the efficacy of both surgical methods. Omentum pedicle and thoracic muscle flaps supply excellent vascularised tissue to fill infected pleural space and mediastinum, particularly in patients with limited cardiopulmonary function.

Adult↗
PubMed1994

Three years experience with a new balloon catheter for the management of haemoptysis.

For the management of severe haemoptysis we have developed a double-lumen, bronchus-blocking catheter that can be introduced through the working channel of a standard fibrebronchoscope. We wondered whether this catheter would be suitable to control pulmonary haemorrhage in clinical practice. Over a period of 36 months, 30 of these catheters were used in 27 patients with moderate and massive pulmonary bleeding from various lesions. Underlying diseases were: malignancies (11), vascular deformities (5), tuberculosis (4), silicosis (2), carcinoids (2), silicosis (2), endometriosis (1), bronchiectasis (1). In 26 cases, the transbronchoscopic balloon tamponade was successful. In one patient, tumour growth close to the carina prevented securing of the balloon and double-lumen tube intubation was required. There were only minor complications attributable to the balloon. With the catheter in place for up to seven days, patients underwent surgery, received radiation, chemotherapy, drug treatment or bronchial arterial embolization. In conclusion, we found this double-lumen, bronchus-blocking device safe and the technique practicable to control pulmonary haemorrhage.

Balloon Occlusion↗
PubMed1994

Theoretical and experimental basis for the development of a dynamic airway stent.

Three major problems are currently associated with airway stents: mucostasis, formation of granulation tissue, and migration. We wanted to determine whether these problems could be solved by a different stent design. Based on theoretical considerations of an idealized trachea, we developed a dynamic bifurcation stent made of silicone which incorporates horseshoe-shaped steel struts. A flexible posterior membrane enables dynamic compression during cough, whilst the clasps maintain the airway lumen in the face of external compression. The design of the stent cast was based upon computed tomographic (CT)-scan studies of the central airways. Its complex shape provides a smoother distribution of pressure on the mucosa; thereby, lowering the stimulus for granulation formation. The bronchial limbs saddle on the carina, preventing displacement. The mechanical behaviours of the new stent and two commercially available stents were compared in an ex-vivo model, utilizing freshly excised tracheae and new visualization techniques. Dynamic (artificial coughs) and static loads (simulating tumour compression or pleural pressures) were applied on excised human tracheae with different stents. Our dynamic stent preserved effective compression of the posterior membrane in response to cough, and also provided lumen stability against extrinsic compression. In comparison, the two commercially available stents did not provide both functions equally well. In conclusion, our newly designed dynamic bifurcation stent shows characteristics which should prove useful in avoiding problems currently associated with airway stents.

Cough↗
PubMed1993

Scar carcinoma of the trachea after tracheotomy. Case report and review of the literature.

We present another case of squamous cell carcinoma of the trachea developed in a tracheotomy scar. In the literature 6 cases of cancer found in tracheotomy scars or tracheostomies are reported. The patients' ages ranged from 6 to 66 years. The interval between tracheotomy and the occurrence of cancer ranged from 3 to 41 years. Local extirpation and radiotherapy were tried. The use of stents is emphasized.

Adult↗