Biodegradable polymeric stents for vascular application in a porcine carotid artery model: English version.

Over the past years the development of biodegradable polymeric stents has made great progress; nevertheless, essential problems must still be solved. Modifications in design and chemical composition should optimize the quality of biodegradable stents and remove the weaknesses. New biodegradable poly-L-lactide/poly-4-hydroxybutyrate (PLLA/P4HB) stents and permanent 316L stents were implantedendovascularly into both common carotid arteries of 10 domestic pigs. At 4 weeks following implantation, computed tomography (CT) angiography was carried out to identify the distal degree of stenosis. The PLLA/P4HB group showed a considerably lower distal degree of stenosis by additional oral application of atorvastatin (mean 39.81 ± 8.57 %) compared to the untreated PLLA/P4HB group without atorvastatin (mean 52.05 ± 5.80 %). The 316L stents showed no differences in the degree of distal stenosis between the group treated with atorvastatin (mean 44.21 ± 2.34 %) and the untreated group (mean 35.65 ± 3.72 %). Biodegradable PLLA/P4HB stents generally represent a promising approach to resolving the existing problems in the use of permanent stents. Restitutio ad integrum is only achievable if a stent is completely degraded.

[In vivo diagnosis of epithelial changes of the oropharynx using confocal microscopy]. / In-vivo-Diagnostik von Epithelveränderungen des Oropharynx mittels konfokaler Mikroskopie.

BACKGROUND: Confocal laser scanning microscopy enables the visualization of the anterior regions of the oropharynx mucosa. The specific aim of this investigation was to evaluate whether this in vivo tool supplies essential information for the surgeon prior to operation or not. PATIENTS AND METHODS: The laser scanning microscope HRT II and Rostock Cornea Module were used in this in vivo study. To obtain comparable images, the specifications of this tool used for all investigations were maintained (63 x water immersion objective lens). The investigations were performed on 9 patients with tongue cancer with primary tumor site and stage I (AJCC) and on 12 patients with head and neck cancer who underwent radiochemotherapy (RCT). Data from 21 patients were compared to those of healthy subjects. RESULTS: The following parameters can be detected using LSM: nuclear density, nuclear size, nucleus/cytoplasm relation, number of nuclei, regularity of cell layers, morphology of cells of a cell layer, and occurrence of cellular junctions. In regard to these parameters, dysplastic and cancerous lesions reveal significant differences compared to healthy tissue of the oropharynx. After RCT several epithelial changes were found, such as keratosis, mild dysplasia, increased vascularization and more cell edema and necrosis. CONCLUSIONS: Consistent differences exist between LSM findings of healthy subjects and those of patients with dysplastic, keratotic and cancerous lesions. Both strong hyperplasia and leukoplakia prevent a visualization of the basement cell layer in the oropharynx. The combination of LSM technology and endoscopy and following further investigations are needed for evaluation of LSM technology in the field of otorhinolaryngology.

Concurrent chemoradiotherapy and adjuvant chemotherapy with Topotecan for patients with glioblastoma multiforme.

PURPOSE: The prognosis for patients with glioblastoma multiforme remains poor. Phase II studies, meta-analyses and a phase III study show that concurrent chemoradiotherapy has an advantage over irradiation alone. In this study the effectiveness of concurrent chemoradiotherapy with Topotecan and an adjuvant chemotherapy with Topotecan was investigated. PATIENTS AND METHOD: Forty-two patients with predominantly unfavourable prognosis factors were included in the study and treated as follows: hyperfractionated accelerated radiotherapy (2x1.75Gy to 45.5 + 12.25 Gy (RP)) with a concurrent, continuous infusion of Topotecan (0.5 mg/m(2)/d, days 1-21). On day 28 the adjuvant chemotherapy (three courses) was begun according to the same scheme. RESULT: Haematological toxicities were 13/42 (30%) grade III leucopenia, 2/42 (4%) grade IV, as well as 5/42 (10%) grade III thrombopenias and 1/42 (2%) grade IV. 30/42 (71%) patients showed improvement or stabilisation of an existing neurological symptomatic complex. The median time to progression was 7.2 (+/- 0.8) months, the median total survival was 10 (+/- 1.2) months, the 2 year survival rate 4.7 (+/- 0.3)%. Prognostic factors were age, surgical radicality, performance status and the tumour volume before therapy. SUMMARY: Concurrent chemoradiotherapy and an adjuvant chemotherapy with Topotecan is feasible at acceptable toxicity levels also for patients with a moderate performance status. The patients benefit from the improvement of the clinical symptomatic complex and, even with unfavourable prognosis factors, have a higher median survival in comparison to data published on similar groups of patients given only radiotherapy.