Eckhart Hahn - Academia.edu (original) (raw)

Papers by Eckhart Hahn

Biomedizinische Technik, 2000

Für die Therapie des Magenfrühkarzinoms konnten speziell in Japan in den letzten 20 Jahren versch... more Für die Therapie des Magenfrühkarzinoms konnten speziell in Japan in den letzten 20 Jahren verschiedene endoskopische, minimal-invasive Therapieformen entwickelt und hierzu umfangreiche Erfahrungen gesammelt werden. Die Endoskopische Mukosaresektion (EMR) bietet hierbei gegenüber ablativen Verfahren den Vorteil der histologischen Gewebegewinnung bei gleichzeitig minimalem Trauma. Unter Einhaltung der Standardkriterien der 'Japanese Research Society for Gastric Cancer' ist die EMR in Japan als kurative Therapie des Magenfrühkarzinoms nicht nur mehr bei Risikopatienten etabliert. Sie gerät auch in Europa zunehmend in den Focus des Interesses. Die Entscheidung zur endoskopischen Therapie im Vergleich zur chirurgischen Therapie kann heute nur an Zentren mit hoher Untersuchungsfrequenz und konsequentem Qualitätsmanagement nach Durchführung eines akkuraten lokalen und systemischen Tumor-Staging mit modernstem Equipement (Video-'Big-chip'-oder Vergrößerungs-Endoskope, Färbetechniken, hochauflösende Endosonographie, Entnahme multipler Biopsien, transkutanem Ultraschall, CT) erfolgen. Eine komplette histologische Aufarbeitung des Tumors nach Resektion ist obligat und hat unter Umständen wesentlichen Einfluß auf das weitere therapeutische Vorgehen. Unter Einhaltung streng definierter Standardkriterien der 'Japanese Research Society for Gastric Cancer' zeigt die EMR Fünf-Jahres-Überlebensraten, die chirurgischen Verfahren vergleichbar sind. In Europa ist die EMR bisher noch nicht als Standard anzusehen und ist erst schrittweise in die Routine einzubeziehen, da die Erfahrungen bisher noch begrenzt sind. Die vorliegende Arbeit gibt eine aktuelle Übersicht zu Techniken endoskopischen Therapie des Magenfrühkarzinoms.

Gastrointestinal Endoscopy, Oct 1, 1999

Background: Endoscopically transmitted infections due to inadequate disinfection are rare but wel... more Background: Endoscopically transmitted infections due to inadequate disinfection are rare but well-recognized complications. A new prototype of a flexible, fiberoptic endoscope has been developed that uses a disposable sheath to cover and protect all working surfaces of the endoscope from contamination. The present study investigated the function, reprocessing, and hygienic status of this endoscope system in comparison with standard systems. Methods: In a prospective, randomized trial, 100 upper endoscopic procedures (50 standard, 50 sheathed) were performed. Analog rating scales were used to evaluate endoscopic performance and reprocessing. Reprocessing time, procedure duration, insertion depth, total instrument downtime, and problems occurring during the procedure were recorded. Microbiologic swabs were obtained from each endoscope. Results: Mean procedure duration was slightly longer with the sheathed system than with standard endoscope (9.9 vs. 8.4 min). Set up and reprocessing times, however, were significantly shorter with the Endosheath (8.9 vs. 48.4 min with the standard endoscope). The disposablesheath endoscope system permits the rate of performance of procedures to be increased by a factor of up to 3.0. Both endoscopists and reprocessing personnel preferred the standard endoscope. No post-procedure sheath leakage or rupture was seen. Conclusion: Our results suggest that the "disposable endoscope" may have important advantages in terms of decreased instrument turnaround time and potentially improved safety.

Gastrointestinal Endoscopy, Apr 1, 2004

Gastrointestinal Endoscopy, Dec 1, 2002

Background: Jejunal feeding is an attractive means for delivering nutrients to critically ill pat... more Background: Jejunal feeding is an attractive means for delivering nutrients to critically ill patients. Nasojejunal tubes may have different advantages and disadvantages that may have important clinical implications. Methods: To compare the suitability of 2 different nasojejunal feeding tubes (Tube A, Dobbhoff; Tube B, Freka-Trelumina) for use by endoscopists and nursing staff, a randomized, controlled, prospective trial was performed in 60 patients. The primary end point was time required for tube placement. Secondary end points were successful placement and nursing problems encountered during clinical use. Results of upper endoscopy were also recorded. Results: Placement took significantly longer with Tube A than Tube B (95% CI for median [11.5, 20.0] minutes vs. [5.5, 7.5] minutes; p < 0.001), and was less successful (73.3% vs. 90%; p = 0.18). Nursing problems occurred significantly more often with Tube A compared with Tube B (11 vs. 1; p < 0.001). Tube B stayed in place significantly longer than Tube A (37 days vs. 21 days; p = 0.034). In 45% of the cases, upper endoscopy provided a diagnosis of potential therapeutic relevance. Conclusions: Selection of a nasojejunal tube for endoscopic placement has significant implications with respect to time required for placement, duration of tube usage and the practicability for nursing staff. Diagnostic upper endoscopy performed concomitantly often reveals findings of clinical importance. (Gastrointest Endosc 2002;56:858-63.) Endoscopic placement of nasojejunal tubes: comparison of 2 different tubes

Gastrointestinal Endoscopy, May 1, 2004

Background: Studies suggest that heparin has anti-inflammatory effects that could prevent acute p... more Background: Studies suggest that heparin has anti-inflammatory effects that could prevent acute post-ERCP pancreatitis. The aim of this investigator-initiated, prospective, randomized, doubleblind, multicenter study was to determine whether low-molecular-weight heparin can prevent acute post-ERCP pancreatitis. Methods: Patients at increased risk for acute post-ERCP pancreatitis based on assessment of known risk factors were randomized to receive low-molecular-weight heparin (Certoparin 3000 IU subcutaneously) or placebo (saline solution 0.3 mL subcutaneously) the day before ERCP. The drug was given 2 hours before and 22 hours after ERCP. Documentation and follow-up included patient history, risk factors for acute post-ERCP pancreatitis, procedure-related data, assessment of pain (visual analogue scale, need for pain medication), laboratory findings before and after ERCP (0, 4, and 24 hours), as well as post-ERCP complications. The two-sided Fisher exact test was used for statistical comparison, and a p value #0.05 was considered significant. Results: A total of 458 patients were enrolled in the study. Data from 10 patients could not be evaluated, leaving 221 patients in the low-molecular-weight heparin group and 227 in the placebo group (total 448 patients; 135 men, 313 women; mean age 58 [15] years). Low-molecular-weight heparin and placebo groups were comparable with regard to risk factors for acute post-ERCP pancreatitis (gender distribution, age <65 years, history of pancreatitis, pancreas divisum, disorders of sphincter of Oddi) and procedure-related data (difficult cannulation, diagnostic or therapeutic ERCP, needle-knife papillotomy, endoscopic sphincterotomy, biliary or pancreatic procedure, pancreatic contrast injection, success and final diagnosis of ERCP). Acute post-ERCP pancreatitis occurred in 8.5% (38/448), with one death resulting from severe pancreatitis. Lowmolecular-weight heparin offered no benefit compared with placebo based on the frequency of acute post-ERCP pancreatitis (low-molecular-weight heparin, 18/221 vs. placebo, 20/227; p = 0.87) and the severity of acute post-ERCP pancreatitis (low-molecular-weight heparin, 14 mild, 3 moderate, one severe; placebo, 18 mild, two moderate, 0 severe). The 24-hour serum amylase values and 24-hour pain scores did not differ significantly between the low-molecular-weight heparin group and the placebo group. Bleeding complications occurred in two patients, both in the low-molecular-weight heparin group (one mild, one moderate). Conclusions: Prophylactic subcutaneous administration of low-molecular-weight heparin does not prevent acute post-ERCP pancreatitis. (Gastrointest Endosc 2004;59:606-13.

Scandinavian Journal of Gastroenterology, 2004

In 1997 Hochberger and Neumann presented the "Erlangen Biosimulation Model" (co... more In 1997 Hochberger and Neumann presented the "Erlangen Biosimulation Model" (commercialized as the "Erlangen Endo-Trainer") at various national and international meetings. The new compactEASIE is a simplified version of the original "Biosimulation Model" (Endo-Trainer) and is specially designed for easy handling. CompactEASIE is reduced in its features, focusing exclusively on flexible endoscopy training. The acceptance of training in endoscopic hemostasis is accepted by workshop participants, as evaluated by a questionnaire on both models. Eleven structured courses on endoscopic hemostasis for doctors and nurses organized by the same endoscopists from 3/1998 to 5/1999 were evaluated using one of both models. The questionnaires were filled in by 207/291 trainees (71%). The Endo-Trainer was used in 4 (n = 103) and the compactEASIE in 7 courses (n = 104). Both simulators were equipped with identical types of specially prepared pig-organ packages consisting of esophagus, stomach and duodenum, including artificial sewn-in vessels, polyps and varices. Blood perfusion was done with a roller pump connected to the sewn-in vessels and blood surrogate. All workshops were identical concerning the course structure: a 30-min theoretical introduction on ulcer bleeding was followed by 2 h of practical training in injection techniques and hemoclip application. The second part of variceal therapy consisted of a 30-min theoretical introduction prior to 2 h of practical training on sclerotherapy, band ligation and cyanoacrylate application. Finally, a questionnaire on the trainees' pre-experience and their rating of the different workshop sections was handed out to each participant. Previous endoscopic experience was comparable in both groups. The training in both simulators was highly accepted by the trainees (compactEASIE 95% excellent and good versus EASIE (Endo-Trainer) 97%) and did not show any significant difference (P = 0.493). Even in the assessment of the single techniques, no statistical difference was observed. Furthermore, the assessments of the closeness to reality and the endoscopic environment in both simulators were identical. Both simulators (Endo-Trainer, compactEASIE) are excellent educational tools for interventional endoscopy with a high level of acceptance. The easy-to-handle, "lightweight" compactEASIE is a significant, progress tool for the future.

Scandinavian Journal of Gastroenterology, 2007

Pancreatic cancer continues to be an urgent clinical problem. We used the novel DNA methyltransfe... more Pancreatic cancer continues to be an urgent clinical problem. We used the novel DNA methyltransferase inhibitor Zebularine and the histone deacetylase inhibitor SAHA to investigate the epigenetic influence on viability and differentiation of the pancreatic cancer cell lines YAP C, DAN G and Panc-89 in vitro and in vivo. Cell vitality, proliferation and expression of PDX-1, cytokeratin 7 and 20, chromogranin A, vimentin, bax and bcl-2 were determined on the protein and mRNA level in vitro and in a subcutaneous xenograft model. A time- and dose-dependent increase of apoptosis, paralleled by decreased proliferation, was observed after incubation with single agents or a combination therapy with lower concentrations. This was associated with up-regulation of pro-apoptotic bax and a phenotypic stabilization by the enhanced expression of cytokeratin 7. In vivo, growth of xenografts was delayed with the most pronounced effect in Panc-89 after 1 week of daily intraperitoneal injections of Zebularine paralleled with CK7 up-regulation and down-regulation of dedifferentiation markers. Epigenetic modulation via inhibition of DNA methyltransferase and histone deacetylase induces apoptosis in human pancreatic cancer cells in vitro and delays xenograft growth in vivo, which is associated with a morphological/molecular phenotypic stabilization. These compounds may therefore be suitable as adjunctive therapeutic agents in the treatment of pancreatic cancer.

Critical Care Medicine, Aug 1, 2002

To determine prevalence, risk factors, and outcome of thrombocytopenia in medical intensive care ... more To determine prevalence, risk factors, and outcome of thrombocytopenia in medical intensive care patients. Design: Prospective observational study. Setting: The 12-bed medical intensive care unit of a university hospital. Patients: All consecutively admitted patients with normal platelet count at admission and an intensive care unit stay of >48 hrs during a 13-month period (n ‫؍‬ 145). Measurements and Main Results: The prevalence of intensive care unit-acquired thrombocytopenia (platelet count, <150.0/nL) was 64 of 145 patients (44%). Intensive care unit mortality was 31% in thrombocytopenic patients and 16% in nonthrombocytopenic patients (p ‫؍‬ .03). Mortality was higher in patients with a nadir platelet count of <100.0/nL (p < .001) and in patients with a drop in platelet count of >30% (p < .001). In nonsurvivors, the decrease in platelet count was greater (p < .001), the nadir platelet count lower (p < .001), and the duration of thrombocytopenia longer (p ‫؍‬ .008) than in survivors. A logistic regression analysis identified septic shock (odds ratio [OR], 3.65; 95% confidence interval [CI], 1.40-9.52), a higher Acute Physiology and Chronic Health Evaluation II Score at admission (OR, 1.06 for 1 point; 95% CI, 1.01-1.12), and a drop in platelet count exceeding 30% (OR, 3.73; 95% CI, 1.24-11.21), but not thrombocytopenia, as independent risk factors for intensive care unit death. Correction of thrombocytopenia was associated with reduced mortality (OR, 0.002; 95% CI, 0-0.08). Major bleeding prevalence and transfusion requirements were significantly higher with thrombocytopenia. Nadir platelet count was the only independent risk factor for bleeding (OR, 4.1 for every 100.0/nL; 95% CI, 1.9-8.8). Independently associated with thrombocytopenia were disseminated intravascular coagulation (OR, 14.94; 95% CI, 3.92-57.00), cardiopulmonary resuscitation as an admission category (OR, 5.17; 95% CI, 1.42-18.85), and a higher Sequential Organ Failure Assessment score (OR, 1.20 for a 1 point change; 95% CI, 1.02-1.40). Conclusions: Thrombocytopenia is common in medical intensive care unit patients. Thrombocytopenic patients have a higher prevalence of bleeding and greater transfusion requirements. A drop in platelet counts of >30%, but not thrombocytopenia per se, is independently associated with intensive care unit death. Serial measurements of platelet counts are important and readily available markers for monitoring the patient's condition. Any drop in platelet count requires urgent clarification. Disseminated intravascular coagulation, signs of organ failure at admission, and cardiopulmonary resuscitation are predictors of intensive care unit-acquired thrombocytopenia.

Ultrasound in Medicine and Biology, Aug 1, 2009

Helicobacter, Dec 24, 2001

Background. Apart form bacterial virulence factors of Helicobacter pylori , certain host factors ... more Background. Apart form bacterial virulence factors of Helicobacter pylori , certain host factors influence the pathogenesis of H. pylori gastritis. In particular, antigastric autoantibodies that are detectable in the sera of a substantial proportion of H. pylori were shown to correlate with the development of gastric atrophy. The aim of this study was to analyze the possible antigastric autoimmune response in H. pylori gastritis at the site where the action is, i.e., in the gastric mucosa. Material and Methods. Gastric biopsy specimens from antrum and corpus mucosa of 24 H. pylori-infected and of 33 noninfected patients were cultured for 3 days, and tissue culture supernatants were analyzed for the amount of locally produced IgA and IgG. Antigastric autoantibodies were screened in the sera and in the su-pernatants by means of immunohistochemistry. Results. The infected patients had significantly higher concentrations of locally produced IgA, whereas the IgG concentrations were virtually the same in infected and noninfected patients. IgG or IgA antigastric autoantibodies, or both, were detectable only in the sera (38%) and supernatants (17%) of infected patients. Interestingly, the patient with the strongest local autoimmune response showed body-predominant H. pylori gastritis, with destruction of gastric glands and atrophy of the body mucosa. Conclusions. These results demonstrate that antigastric autoimmune reactions are detectable at the site of the disease and might be relevant for the pathogenesis of gastric mucosa atrophy in H. pylori gastritis.

Gastrointestinal Endoscopy, 1993

This report describes the initial clinical implementation of a new laser lithotripter system capa... more This report describes the initial clinical implementation of a new laser lithotripter system capable of effective fragmentation of common bile duct stones with a high degree of safety provided by an integrated stone-tissue detection system. This system automatically terminates laser ...

International Journal of Oncology, Jun 4, 2009

Tumor cells have the capability to trans-and to dedifferentiate, for example by reactivating embr... more Tumor cells have the capability to trans-and to dedifferentiate, for example by reactivating embryonic development genes and stem cell characteristics. The aim of our study was to show the differential expression of stem-and progenitor cell markers in human hepatocellular carcinoma cell lines (HCC). Different human HCC cell lines (HUH7, HUH7 5-15, HUH7 pcDNA3.1, Hep3B and HepG2) were cultured under standard conditions in vitro or implanted subcutaneously (5x10 6 cells) in male NMRI mice. Specimens were characterized by quantitative real-time PCR, Western blotting, methylation-specific PCR and immunohistochemistry for markers of differentiation (cytokeratins, vimentin), embryonic development or stem cells (PTC, PDX-1, SHH, Thy1, c-kit, CD34, ß-catenin, Ki-67). The investigated HCC cell lines showed different patterns of marker expression allowing to distinguish four distinct groups: the classical cholangiocellular type (Huh-7, Huh-7 pcDNA3.1, Hep3B) with expression of CK7/19, ß-catenin and CD34; a dedifferentiated mesenchymal-proliferative type (Huh-7 5-15) characterized by CK19, Vimentin and Ki-67; a dedifferentiated embryonic-development type (Hep3B implanted in matrigel) with expression of CK19, ß-catenin and PTC and a classical HCC type (HepG2) showing CK18/19 and ß-catenin expression. HCC cell lines showed significantly different expression patterns of differentiation markers in a xenograft model. Furthermore, direct association of some markers was observed. The groups differ from each other in expression patterns, but also show that environmental factors play an important role in the behaviour of cells.

Gastrointestinal Endoscopy, Feb 1, 2005

The Erlangen Active Simulator for Interventional Endoscopy (EASIE) was introduced in 1997 for int... more The Erlangen Active Simulator for Interventional Endoscopy (EASIE) was introduced in 1997 for interventional endoscopy training. compactEASIE developed in 1998 is a modified, light-weight version of the original model. Objective evidence of the benefits of training with these models is limited. A randomized controlled study, therefore, was conducted to compare the effects of intensive 7-month, hands-on training in hemostatic techniques by using the compactEASIE model (in addition to clinical endoscopic training) vs. pure clinical training in endoscopic hemostatic methods. Thirty-seven fellows in gastroenterology in New York City area training programs were enrolled. Baseline skills were assessed on the simulator for the following techniques: manual skills, injection and electrocoagulation, hemoclip application, and variceal ligation. Twenty-eight fellows were then randomized into two comparable groups. Those randomized to Group A received purely clinical training in endoscopic hemostatic techniques at their hospitals. Those in Group B, in addition, were trained by experienced tutors in 3 full-day hemostasis workshops over 7 months. Both groups underwent a final evaluation on the compactEASIE simulator conducted by their tutors and additional evaluators who were blinded to the method of training. Initial and final evaluation scores were compared for each group and between groups. Outcomes of actual clinical hemostatic procedures performed during the study period also were analyzed. Ten of 14 fellows randomized to Group A (standard training) and 13 of 14 in Group B (intensive training) returned for the final evaluation. For Group B, scores for all techniques were significantly improved. In Group A, a significant improvement was noted for variceal ligation alone. compactEASIE simulator training (3 sessions over 7 months), together with clinical endoscopic training resulted in objective improvement in the performance by fellows of all 4 endoscopic hemostatic techniques, whereas significant improvement was noted for variceal ligation alone for fellows who had standard clinical training. In clinical practice, fellows who had intensive simulator/clinical training had a significantly higher success rate and a nonsignificant reduction in the frequency of occurrence of complications.

International Journal of Pancreatology, Apr 1, 1995

The contribution of ethanol to the pathogenesis of acute pancreatitis has been questioned for a l... more The contribution of ethanol to the pathogenesis of acute pancreatitis has been questioned for a long time. The authors asked whether acute ingestion of large amounts of alcohol may lead to pancreatic injury, as assessed by serum amylase levels, clinical picture, and abdominal ultrasound. Therefore, all patients (N = 122) admitted to our medical emergency ward with the diagnosis of alcohol intoxication were evaluated prospectively during a 12-mo period. Of these, 78 (56 M, 22 F; mean age 36 + 15) could be evaluated. The other 44 were excluded because of incomplete data (n = 18), mixed intoxications (n = 8), repeated admission (n = 9), incorrect diagnosis on admission (n = 7), and chronic pancreatitis (n = 2). Serum ethanol, amylase, and GOT were measured. Serum ethanol was 246 + 122 mg/dL (3-500 mg/dL), amylase 83 + 44 U/L (27-361 U/L), and GOT 25 + 37 U/L (5-271 U/L) without significant differences among the genders. No correlation between serum ethanol and serum amylase levels could be detected.

Biomedizinische Technik, 1997

Gastrointestinal Endoscopy, Apr 1, 1997

Endoscopy, Sep 1, 2002

... J. Hochberger 1 , J. Maiss 1 , EG Hahn 1. 1 Department of Medicine I, Friedrich Alexander Uni... more ... J. Hochberger 1 , J. Maiss 1 , EG Hahn 1. 1 Department of Medicine I, Friedrich Alexander University, Erlangen, Germany. ... Endoscopy 2000; 32: 898-900 3 Aabakken L, Adamsen S, Kruse A. Performance of a colonoscopy simulator: Experience from a hands-on endoscpy course. ...

Gastroenterology, Nov 1, 1991

Gastrointestinal Endoscopy Clinics of North America, Oct 1, 2003

More than 80% of all CBD stones can be effectively treated by endoscopic sphincterotomy and stone... more More than 80% of all CBD stones can be effectively treated by endoscopic sphincterotomy and stone extraction using baskets or balloon catheters. For stones up to 2.5 cm in diameter, mechanical lithotripsy is the method of choice as a next step. Very large, impacted, or very hard concretions, however, often make mechanical lithotripsy cumbersome or even impossible. For these stones laser lithotripsy, EHL, and ESWL are nonoperative options, especially for elderly patients and patients with an elevated surgical risk. Because these methods are often only available at endoscopic centers, stenting is a treatment modality for immediate stone therapy, but as a definitive treatment it should be restricted to selected cases. ESWL, EHL, and laser lithotripsy yield similar success rates of 80% to 95% and may be used complementarily in endoscopic centers. ESWL is the preferred therapy in intrahepatic lithiasis. Laser lithotripsy shows the best results in CBD stones. Electrohydraulic lithotripsy is rarely used because of its high potential for tissue damage and bleeding. Laser lithotripsy using smart laser systems such as the rhodamine 6G dye laser and the FREDDY laser system can simplify the treatment of these difficult bile duct stones. The rhodamine 6G-dye laser allows blind fragmentation of these stones by exclusive insertion of a 7-F metal marked standard catheter into the bile duct by standard duodenoscopes using intermittent fluoroscopy. An oSTDS safely cuts off the laser pulse if contact with the stone is lost, thus preserving the bile duct from potential damage. Unfortunately the system is no longer produced. The new FREDDY laser lithotriptor with a piezoacoustic stone/tissue discrimination system offers an alternative to the rhodamine 6G dye laser system at less than half the financial investment. Effective stone fragmentation is accompanied by only low tissue alteration. The holmium:YAG laser is an effective multidisciplinary lithotriptor, but it can be used only under cholangioscopic control, limiting its use to gastroenterologic centers.

Hepatology, Aug 1, 2001

P14 Facial continuous positive airway pressure therapy for cardiogenic pulmonary oedema: a study ... more P14 Facial continuous positive airway pressure therapy for cardiogenic pulmonary oedema: a study of its efficacy in an emergency department setting within the UK