Biomedical subjects

K-M Müller

Publications and source records attributed to K-M Müller.

48 records · Page 3Linked to original sources

PubMed2003

[Thoracic aortic aneurysm in the setting of metastatic mediastinitis].

The aetiological spectrum of thoracic aortic aneurysms is extensive. Infectious aneurysms (formerly mycotic aneurysms) constitute only a small percentage of all thoracic aortic aneurysms, they are usually small and often develop as complications of bacterial endocarditis. We report the case of a 39-year-old insulin-dependent diabetic, who developed a leaking aneurysm of the thoracic aorta as a late complication of a knee empyema with subsequent metastatic mediastinitis. Clinical, radiological, biochemical and microbiological data are correlated with histopathological findings. The development of this unusual thoracic aortic aneurysm is shown from impending rupture to successful vascular graft implantation.

Adult↗

PubMed2003

[Ossification in lung metastases of primary colorectal adenocarcinomas].

Ossification of lung tissue is a rare phenomenon, which can be found in association with carcinoid tumors of the lung or pulmonary blastomas. Very rarely, ossifications are observed in lung metastases of extrathoracal epithelial tumors. In these cases, the most probable primary focus is a colorectal adenocarcinoma. Our question was, whether ossifications in lung metastases are pathognomonic for colorectal adenocarcinomas and how they can be pathogenetically arranged. A total of 15 lung metastases with ossifications from 5 patients suffering from a colorectal adenocarcinoma were examined by means of immunohistochemistry. Thereby, we found an increased expression of bone morphogenetic protein (BMP) 2/4 and osteonectin in tumor cells, as well as an increased stromatogenous expression of collagen type III. We conclude that there is strong evidence of a primary colorectal adenocarcinoma when ossifications in lung metastases are found. In these cases, a common metastatic spread of tumor cells and tumor stroma seems to be probable.

Adenocarcinoma↗

PubMed2003

[Neoadjuvant therapy in non-small cell lung cancer. Prognostic impact of "mediastinal downstaging"].

In the course of a prospective multicenter study, 40 (26 squamous cell and 14 adenocarcinomas) patients with stage IIIA and IIIB non-small cell lung cancer (NSCLC) were submitted to surgery after neoadjuvant radiochemotherapy. Pretherapeutic clinical lymph node status was compared to the lymph node involvement established in the resection specimens. Therapy-induced tumor regression was classified according to a three-step tumor regression grading system. In 29 patients (72.5%) a downward shift in lymph node involvement could be established,whereas in 27.5% ( n=11) pretherapeutic lymph node status was maintained. Of 26 patients with post-therapeutic N0 or N1 status, 21 revealed less than 10% vital tumor tissue in the resection specimens (regression grades IIb or III). Patients with post-therapeutic N0 or N1 lymph node status were found to have a survival benefit compared to patients with N2 lymph node involvement, though this difference was not statistically significant (p=0.27). On the other hand, tumor regression showed a significant correlation to the overall survival period (p=0.02). Thus, therapy-induced tumor regression grading seems to be a more precise method to predict the outcome of the disease.

Adenocarcinoma↗

PubMed2003

[Aneurysms in arterio-venous synthetic shunts after dialysis therapy. Morphology and pathogenesis].

Synthetic grafts are used as arterio-venous fistulae (shunts) for dialysis therapy of patients with chronic renal insufficiency. Today grafts made of PTFE (polytetrafluorethylene) are commonly used. Grafts with diameter of 6 mm are implanted subcutaneously. In rare cases stenosis or thrombosis cause explantation of the grafts. Our results, obtained on 10 samples taken from surgery or autopsy, revealed that the main causes for graft explantation are destructions and perforations of the graft's wall caused by needle puncturing during dialysis. Single defects of the implants wall ranging from 200-500 micro m, and in some cases up to 1,5 mm are "repaired" by connective tissue. But greater defects cannot be compensated and are insufficiently covered by a network of loose connective tissue. These zones are under the predominated sites for development of false prosthetic aneurysm, which show parallel to posttraumatic aneurysms of vessels. Prosthetic aneurysms up to diameters of 3,2 cm were seen. Suitable choice of puncturing sites and puncturing technique can help to avoid destruction of the synthetic material.

Aneurysm↗

PubMed2003

[Intraoperative cooled-tip radiofrequency ablation in patients with atrial fibrillation undergoing open heart surgery].

METHODS: A total of 113 patients with chronic permanent (104) or paroxysmal (9) atrial fibrillation underwent open heart surgery plus an additional antiarrhythmic procedure using saline-irrigated cooled-tip radiofrequency ablation (SICTRA) for biatrial or left atrial linear lesions. Ablation was performed with steps of short (5 seconds) ablation around the pulmonary vein ostia and interconnecting lines. Postoperative complications and conversions to sinus rhythm were followed up (mean follow-up duration 17+/-14 months). RESULTS: Of the 113 patients, 16 died during follow-up (day 3 up to 33 months) resulting in a cumulative survival of 79% (2 sudden cardiac deaths, 2 gastrointestinal bleedings, 1 renal bleeding, 2 mediastinitis, 1 endocarditis, 1 hemorrhagic insult, 2 respiratory insufficiencies and 2 unknown). Three patients died between day 3 and 6 (30-day mortality 3%) due to low cardiac output. Complications occurred in 19% of the patients including 4% bleeding, 1% pneumothorax, 3% sternal dehiscence, 3% reversible low cardiac output, 6% reversible respiratory insufficiency, 2% TIAs and 1% intra aortal balloon pump implantation. Conversion to sinus rhythm usually occurred spontaneously within 6 months resulting in a cumulative percentage of 80% in sinus rhythm. In these patients, 85% showed biatrial contraction. CONCLUSIONS: SICTRA to treat atrial fibrillation can safely and effectively be combined with different surgical procedures. Mortality and complication rates are comparable to cardiac surgery without antiarrhythmic procedures. No severe procedure-related complications were noted when a stepwise ablation approach during open heart surgery was used. Antiarrhythmic surgical procedures are highly effective in restoring sinus rhythm in patients with atrial fibrillation. Is a modified approach using intraoperatively cooled-tip radiofrequency ablation to induce linear lesions safe and effective in the treatment of atrial fibrillation in cardiosurgical patients?

Aged↗

PubMed2003

[Interstitial pulmonary siderofibrosis: requirements for acceptance as new occupational disease].

BACKGROUND: Pulmonary siderosis is a well established disorder in welders. Internationally more than 150 cases of interstitial pulmonary siderofibrosis are associated with long-standing and heavy exposure to welding fumes at poorly ventilated working places. PATIENTS: Characteristic job histories, lung function analyses and histological examinations as well as elemental microanalysis by energy dispersive X-ray analysis (EDX) are demonstrated from 3 welders with pulmonary siderofibrosis. RESULTS: Histological examinations show a patchy interstitial fibrosis with accumulations of particulate material typical for welding fumes. EDX disclose an increase of iron-load in activated macrophages as well as in lung tissue and a close topographical relationship of welding fume particles and interstitial fibrotic reactions. Lung function analysis showed predominantly loss of pulmonary performance during spiroergometry. CONCLUSIONS: Regarding the actual knowledge about the pathomechanisms of ultrafine particles on lung tissue, the evidence from animal experiments, the histological and electron microscopical results, our own clinical examinations of welders and some epidemiological evidence, we assume a causal relationship of interstitial pulmonary siderofibrosis in welders with long-standing exposure to high concentrations of welding fumes under poor working conditions.

Adult↗

PubMed2003

[Virtual multislice-CT-bronchoscopy as a diagnostic tool in patients with endobronchial tumors: case report of a carcinoid tumor].

BACKGROUND: Bronchial carcinoids are rare neuroendocrine tumors of the lung. Diagnosis is established by computed tomography (CT) and bronchoscopy-guided biopsy. Imaging features of carcinoids are highly characteristic including contrast enhancement and central intraluminal growth. Multislice-CT generated three-dimensional virtual bronchoscopy enables non-invasive and detailed view of the tracheobronchial system. CASE REPORT: A 70-year-old male with known silicosis and chronic cough with hemoptysis showed hypertransparency of the left lung on conventional images. Axial CT scans revealed a solid tumor in the left lower lobe. Virtual CT-bronchoscopy based on surface rendering depicted an intraluminal mass occluding the bronchus of the anterobasal segment that was confirmed by conventional endoscopy. Conventional and virtual bronchoscopy showed almost identical imaging features. Histopathological evaluation of the bioptic specimen revealed a typical carcinoid tumor. The patient successfully underwent resection of the left lower lobe with mediastinal lymphadenectomy. CONCLUSIONS: Virtual Multislice-CT-bronchoscopy can add important information about an intraluminal tumor and its relation to surrounding structures. Further studies have to be undertaken to evaluate the potentials of this promising method as a tool to determine endoluminal growth in tumorous lung lesions.

Aged↗

PubMed2003

Mycoplasma pneumoniae associated organising pneumonia in a 10 year old boy.

We describe a 10 year old boy with organising pneumonia associated with acute Mycoplasma pneumoniae infection. The diagnosis of organising pneumonia was made by open lung biopsy and the M pneumoniae infection was proven serologically. Antibiotic and long term corticosteroid treatment resulted in steadily improving pulmonary function monitored by spirometry. The introduction of anti-inflammatory treatment with NSAIDs/immunosuppressive agents in order to spare steroids was well tolerated and resulted in further improvement of the pulmonary function. To our knowledge this is the first documented case of Mycoplasma pneumoniae associated organising pneumonia to be reported in a child.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2002

[Mesotheliomas in academics. German mesothelioma register in Bochum].

Of a total of 4455 persons with mesotheliomas listed in the German register of mesotheliomas, 72 patients have an academic education in whom exposure to asbestos would not necessarily be assumed at first. Only one patient in this group was female. The tumors were located in the pleura in 94% ( n=68) and in the peritoneum in 6% ( n=4). The mean age at the time of diagnosis was 59.1 years. The mean survival time was 10.2 months. The epitheloid subtype predominated (57.7%, n=41) followed by the biphasic subtype (33.8%, n=24). Development of the sarcomatoid subtype was the least common (8.5%, n=6). Lung dust analysis provided proof for elevated pulmonary asbestos load in 78.2% of the patients. Work-related or non-work-related exposure to asbestos was cited or at least suspected by 68% ( n=49) of the patients. The mean latency period was 36.8 years. Thus, in those patients with an academic career the majority of mesotheliomas can be considered associated with asbestos.

Faculty↗

PubMed2002

Dosimetric measurements in isolated human coronary arteries: comparison of commercially available iridium(192) with strontium/yttrium(90) emitters.

BACKGROUND: Intravascular brachytherapy is being applied more and more in patients with coronary artery disease for the prevention of restenosis subsequent to balloon angioplasty, in particular after stent implantation. Several radiation sources (beta- and gamma-emitters) are available in clinical routine. It was the purpose of this study to compare the radiation doses at the level of the adventitia in diseased and stented human coronary arteries for (192)Ir and (90)Sr/Y emitters in routine use. In contrast to previously published work, we performed dosimetry instead of calculating depth-dose distribution by use of the Monte Carlo system. METHODS AND RESULTS: Postmortem calcified human coronary artery segments were stented and placed in an organ bath. Commercially available gamma-emitters ((192)Ir; Cordis Checkmate) and beta-emitters ((90)Sr/Y; Novoste Beta-Cath) were used. Relative dose distributions along the adventitia were measured by a specially designed scintillation detector system. Whereas dose perturbations caused by stents and calcified plaque were negligible for the (192)Ir source, radiation from the beta source was significantly impaired (as much as 40%) at the level of the adventitia (3.0-mm vessel diameter). Dose perturbation was clearly dependent on the extent and severity of calcification, less affected by stent material. CONCLUSIONS: Dose perturbation caused by calcified plaque and metallic stents is significant for beta-sources. This dosimetric difference between beta- and gamma-emitters in diseased coronary arteries should be considered when calculating doses in intravascular brachytherapy.

Beta Particles↗

PubMed2002

Efficacy of an additional MAZE procedure using cooled-tip radiofrequency ablation in patients with chronic atrial fibrillation and mitral valve disease. A randomized, prospective trial.

AIMS: This study is the first prospective randomized trial evaluating the efficacy of an antiarrhythmic surgical procedure in patients with chronic atrial fibrillation undergoing mitral valve replacement. METHODS AND RESULTS: Thirty consecutive patients with chronic atrial fibrillation undergoing mitral valve replacement were randomized for an additional modified MAZE-operation using intra-operatively cooled-tip radiofrequency ablation (group A) or mitral valve replacement alone (group B). Biatrial contraction was studied and functional capacity was evaluated in spiro-ergometry 6 months after surgery. Thirty-day mortality was 0% in both groups. After 12 months, sinus rhythm was reinstituted significantly more often in patients of group A (cumulative rate of sinus rhythm 0.800) compared to patients in group B (0.267) (P<0.01). 66.7% of patients in sinus rhythm of group A had documented biatrial contraction. Electrocardioversion showed long-term success in only 17% of patients in group A and 0% in group B. Maximal aerobic uptake at the 6-month spiro-ergometry revealed no significant difference (9.3 vs 8.5 ml x min(-1) kg(-1), P=0.530). CONCLUSIONS: A modified MAZE operation using cooled-tip radiofrequency ablation can be safely combined with mitral valve surgery and is highly effective in restoring sinus rhythm. Biatrial contraction is found in 66.7% of patients with sinus rhythm undergoing mitral valve replacement plus the MAZE operation.

Aged↗

PubMed2002

Black spots of the parietal pleura: morphology and formal pathogenesis.

BACKGROUND: Dark incorporations (black spots) have been described in various organs. 'Black spots' seen as flat-to-nodular lesions of the parietal pleura are common findings in former miners. They represent areas of coal dust accumulation. An increased incorporation of asbestos fibres has been described in these areas, causing them to be seen as potential starting points for malignant mesotheliomas. OBJECTIVES: The aim of our examinations was to describe the morphology of black spots in order to understand their formal pathogenesis and discuss their role in the development of malignant mesotheliomas. MATERIALS: We report the results of the morphological and energy dispersive X-ray analysis of 12 black spots (4 surgical and 8 autopsy specimens) located in the parietal pleura. RESULTS: Black spots of the pleura develop in close correlation to lymphatic channels and blood vessels. Their formal pathogenesis is characterized by a mild fibrosis and an inflammatory reaction to the incorporated foreign particles. The proliferation of connective tissue may result in the formation of hyaline granulomas. Aluminum, silicone and sometimes fibres are also found in such areas. Mesothelial cells may be irritated. CONCLUSION: Although there are hints for an increased proliferation of mesothelial cells in some areas with black spots, our findings do not support the classification of black spots as an obligate early lesion in the development of malignant mesotheliomas.

Dust↗