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Featured researches published by A Nägel.


Gastrointestinal Endoscopy | 2012

Description of a new, endoscopic technique to remove the over-the-scope-clip in an ex vivo porcine model (with video)

Helmut Neumann; Hiwot Diebel; Klaus Mönkemüller; A Nägel; D Wildner; Michael Vieth; Jürgen Siebler; Markus F. Neurath

BACKGROUND Various studies have demonstrated the usefulness of the over-the-scope-clip (OTSC) to treat perforations, anastomotic leaks, and fistulae. Endoscopic removal of the OTSC was previously described in a series of 3 patients by using the Nd:YAG laser. OBJECTIVE To evaluate a new endoscopic technique to remove the OTSC. DESIGN Prospective, single-arm, pilot study in an ex vivo porcine model. INTERVENTIONS Perforations were created by using a surgical scalpel and a blunt trocar. Then they were endoscopically closed with the OTSC. Next, the OTSC was removed under endoscopic control by inserting a 0.035-inch straight hydrophilic tip guidewire into the oval hole on the side of the OTSC jaw. Afterward, the OTSC clip was removed by pulling on the wire. RESULTS Fifteen perforations were closed: with the OTSC. In all of the cases, the endoscopic closure of the defects was feasible and effective. Successful visualization of the oval hole of the OTSC was possible in 12 cases (80%), and guidewire cannulation was possible in all of these 12 cases (100%). Advancement of the guidewire through the OTSC and then the lumen of the stomach was accomplished in 8 cases (53.3%). In all of the cases with successful cannulation of the orifice, removal of the OTSC was managed safely. The result was an overall success rate of 53.3% (8 of 15 cases). LIMITATIONS Ex vivo porcine model. CONCLUSIONS Guidewire removal is a new and feasible technique to remove the OTSC. Future studies should refine the technique to enhance visualization and cannulation of the oval hole of the OTSC.


Current Opinion in Gastroenterology | 2014

Wireless capsule endoscopy of the small intestine: a review with future directions.

Helmut Neumann; Lucia C. Fry; A Nägel; Markus F. Neurath

Purpose of review Here, we review the clinical applications of small bowel capsule endoscopy. Moreover, we provide an outlook on the exceptional future developments of small bowel capsule endoscopy. We discuss clinical algorithms for diagnosis of small bowel diseases. Multiple studies have shown the potential of capsule endoscopy for identification of the bleeding source located in the small bowel and the increased diagnostic yield over radiographic studies. Capsule endoscopy could detect villous atrophy and severe complications in patients with nonresponsive celiac disease. In addition, small bowel capsule endoscopy was proven as a valid tool to diagnose polyps and tumors and Crohns disease. Summary Major current clinical indications of capsule endoscopy in the small bowel include evaluation of obscure gastrointestinal bleeding, diagnosis and surveillance of small bowel polyps and tumors, celiac disease and Crohns disease. Recent developments have also passed the way for small bowel capsule endoscopy to become a therapeutic instrument.


Digestion | 2008

Long-Term Partial Remission of AutoImmune Thrombocytopenia in a Patient Treated with the Anti-Tumor Necrosis Factor-Alpha Antibody Infliximab for Refractory Fistulizing Crohn’s Disease

Norbert Krauss; Reinhard E. Voll; A Nägel; Michael Weidenhiller; Peter C. Konturek; Eckhart G. Hahn; Martin Raithel

Background: Up to the present date, the treatment of recurrent chronic fistulas occurring with Crohn’s disease represents a challenging task for both internists and surgeons alike. Methods: Conservative methods of treatment using steroids, dietotherapy, antibiotics or immunosuppressive agents are not particularly effective in treating fistulas. Treatment with anti-tumor necrosis factor-α (TNFα) antibodies results in more remissions of fistulas. However, its use requires appropriate medical experience and causes substantial costs. Surgical procedures such as fistula sanitation or protective ileostomy are often obfuscated by the recurrence of the condition. The efficiency of anti-TNFα antibodies for the treatment of active Crohn’s disease has been evidenced through several multicenter, double-blind, placebo-controlled studies. Results: Here we report the successful anti-TNFα treatment of a patient suffering from chronic, fistulizing, therapy-resistant Crohn‘s disease and a concomitant chronic autoimmune thrombocytopenia. The chimeric anti-TNFα antibody infliximab markedly reduced the disease activity of Crohn’s disease, and, in addition, substantially increased the platelet counts. After infliximab application, no other treatment of autoimmune thrombocytopenia was required. After infliximab therapy, autoantibodies to dsDNS could be observed. However, there were no signs of a lupus-like disease. Conclusion: This report indicates a favorable therapeutic response of autoimmune thrombocytopenia associated to Crohn’s disease.


World Journal of Gastrointestinal Endoscopy | 2015

Advanced endoscopic imaging to improve adenoma detection

Helmut Neumann; A Nägel; Andrea Buda

Advanced endoscopic imaging is revolutionizing our way on how to diagnose and treat colorectal lesions. Within recent years a variety of modern endoscopic imaging techniques was introduced to improve adenoma detection rates. Those include high-definition imaging, dye-less chromoendoscopy techniques and novel, highly flexible endoscopes, some of them equipped with balloons or multiple lenses in order to improve adenoma detection rates. In this review we will focus on the newest developments in the field of colonoscopic imaging to improve adenoma detection rates. Described techniques include high-definition imaging, optical chromoendoscopy techniques, virtual chromoendoscopy techniques, the Third Eye Retroscope and other retroviewing devices, the G-EYE endoscope and the Full Spectrum Endoscopy-system.


Journal of Clinical Gastroenterology | 2016

Digital Chromoendoscopy With i-Scan for In Vivo Prediction of Advanced Colorectal Neoplasia: A Multicenter Study.

H Albrecht; A Nägel; Hüseyin Tasdelen; Timo Rath; Martin Grauer; Michael Vieth; Markus F. Neurath; Helmut Neumann

Background: Recent studies have analyzed the potential of advanced endoscopic imaging techniques for differentiating hyperplastic and adenomatous colorectal lesions. Latest endoscopic resection techniques now also allow for treatment of more advanced staged lesions including treatment of early cancerous lesions. Aims: To assess the potential of the i-scan technology to differentiate between adenomatous polyps and advanced staged neoplasia. Methods: Consecutive patients undergoing colonoscopy at a tertiary referral center were included. After a dedicated training, participating endoscopists underwent a review of 298 unknown images of colonic lesions to assess colorectal lesion histology. Results: Overall accuracy for prediction of advanced staged neoplasia was 92.2% (sensitivity: 94.2%, specificity 90.9%). The positive and negative predictive values were calculated as 87.5% and 95.9%, respectively. The &kgr;-value for differentiating adenomatous polyps and advanced staged neoplasia was 0.8193 (0.7894 to 0.8492). Intraobserver agreement was calculated with a &kgr;-value of 0.9301 (0.8875 to 0.9727). Conclusions: Accurate interpretation of i-scan images for prediction of advanced colorectal neoplasia can successfully be performed even by nonexpert endoscopists with a high overall accuracy and excellent interobserver agreements.


Gastroenterology Research and Practice | 2017

The Application of Hemospray in Gastrointestinal Bleeding during Emergency Endoscopy

A Hagel; H Albrecht; A Nägel; Francesco Vitali; Marcel Vetter; Christine Dauth; Markus F. Neurath; Martin Raithel

Introduction. Gastrointestinal bleeding represents the main indication for emergency endoscopy (EE). Lately, several hemostatic powders have been released to facilitate EE. Methods. We evaluated all EE in which Hemospray was used as primary or salvage therapy, with regard to short- and long-term hemostasis and complications. Results. We conducted 677 EE in 474 patients (488 examinations in 344 patients were upper GI endoscopies). Hemospray was applied during 35 examinations in 27 patients (19 males), 33 during upper and 2 during lower endoscopy. It was used after previous treatment in 21 examinations (60%) and in 14 (40%) as salvage therapy. Short-term success was reached in 34 of 35 applications (97.1%), while long-term success occurred in 23 applications (65.7%). Similar long-term results were found after primary application (64,3%) or salvage therapy (66,7%). Rebleeding was found in malignant and extended ulcers. One major adverse event (2.8%) occurred with gastric perforation after Hemospray application. Discussion. Hemospray achieved short-term hemostasis in virtually all cases. The long-term effect is mainly determined by the type of bleeding source, but not whether it was applied as first line or salvage therapy. But, even in the failures, patients had benefit from hemodynamic stabilization and consecutive interventions in optimized conditions.


Case reports in gastrointestinal medicine | 2017

A Severe Case of Tuberculosis Radiologically and Endoscopically Mimicking Colorectal Cancer with Peritoneal Carcinomatosis

Timo Rath; Raja Atreya; Walter Geißdörfer; Roland Lang; A Nägel; Markus F. Neurath

Although generally rising in incidence, intestinal tuberculosis is still rare in western countries and due to unspecific manifestations mainly as ulcerations on endoscopy, diagnosis of intestinal tuberculosis is challenging. Within this report, we describe a case of severe intestinal tuberculosis radiologically and endoscopically masquerading as colorectal cancer with peritoneal carcinomatosis. Our case exemplifies that intestinal tuberculosis needs to be considered as a differential diagnosis in patients at risk and that undelayed and sensitive diagnosis of intestinal tuberculosis is of central importance for avoiding unfavorable disease outcome.


World Journal of Gastroenterology | 2013

Conventional endoscopic retrograde cholangiopancreaticography vs the Olympus V-scope system

Martin Raithel; A Nägel; Jürgen Maiss; D Wildner; A Hagel; Sandra Braun; Hiwot Diebel; E. G. Hahn

AIM To compare the new Olympus V-scope (VS) to conventional endoscopic retrograde cholangiopancreaticography (ERCP). METHODS Forty-nine patients with previous endoscopic papillotomy who were admitted for interventional ERCP for one of several reasons were included in this single-centre, prospective randomized study. Consecutive patients were randomized to either the VS group or to the conventional ERCP group. ERCP-naïve patients who had not undergone papillotomy were excluded. The main study parameters were interventional examination time, X-ray time and dose, and premedication dose (all given below as the median, range) and were investigated in addition to each patients clinical outcome and complications. Subjective scores to assess each procedure were also provided by the physicians and endoscopy assistants who carried out the procedures. A statistical analysis was carried out using the Wilcoxon rank-sum test. RESULTS Twenty-five patients with 50 interventions were examined with the VS ERCP technique, and 24 patients with 47 interventions were examined using the conventional ERCP technique. There were no significant differences between the two groups regarding the age, sex, indications, degree of ERCP difficulty, or interventions performed. The main study parameters in the VS group showed a nonsignificant trend towards a shorter interventional examination time (29 min, 5-50 min vs 31 min, 7-90 min, P = 0.28), shorter X-ray time (5.8 min, 0.6-14.1 min vs 6.1 min, 1.6-18.8 min, P = 0.48), and lower X-ray dose (1351 cGy/m(2), 159-5039 cGy/m(2) vs 1296 cGy/m(2), 202.2-6421 cGy/m(2), P = 0.34). A nonsignificant trend towards fewer adverse events occurred in the VS group as compared with the conventional ERCP group (cholangitis: 12% vs 16%, P = 0.12; pain: 4% vs 12.5%, P = 0.33; post-ERCP pancreatitis: 4% vs 12.5%, P = 0.14). In addition, there were no statistically significant differences in assessment by the physicians and endoscopy assistants using subjective questionnaires. CONCLUSION ERCP using the short-guidewire V-system did not significantly improve ERCP performance or patient outcomes, but it may reduce and simplify the ERCP procedure in difficult settings.


Endoscopy International Open | 2018

Treatment of Zenker’s diverticulum using a novel grasping-type scissors forceps allows fast, safe, and effective endoscopic diverticulotomy

Timo Rath; Jürgen Siebler; Markus F. Neurath; A Nägel

Background and study aims  Although several endoscopic techniques have been described for Zenker’s diverticulotomy, no standardized endoscopic approach has been established in clinical routine to date. This study aimed to assess the efficacy and safety of endoscopic diverticulotomy using the Clutch Cutter. Patients and methods  Cricopharyngeal myotomy was performed in six prospectively enrolled patients with symptomatic Zenker’s diverticulum, using the Clutch Cutter. Procedural details such as duration, complications, and technical success were recorded and compared to the outcomes of 15 patients who received needle-knife-based myotomy. Results  Myotomy with the Clutch Cutter was feasible in all six patients with complete diverticulotomy in a single session in all patients. Mean procedure time of the Clutch Cutter myotomy was 19 minutes without major complications. During follow-up, one patient had diverticulum recurrence after 10 months, which was successfully re-treated. Mean procedure time with the needle-knife was 43 minutes and a mean of 2.7 myotomy sessions was required for complete diverticulotomy. Conclusion  Endoscopic diverticulotomy using the Clutch Cutter is safe, effective, and fast. Larger studies comparing myotomy using the Clutch Cutter with other endoscopic techniques are highly warranted.


Hno | 2012

Foreign bodies in the upper gastrointestinal tract

Maiss J; Martin Raithel; A Nägel

Foreign bodies in the upper GI tract are an important medical problem and cause about 5% of emergency endoscopies. Endoscopic removal is the method of the choice and is successful in 99% of cases. Nevertheless, endoscopic removal is not necessary in every case because most foreign bodies can pass through the digestive tract and be evacuated in the natural way. An immediate emergency endoscopy is indicated for foreign bodies in the esophagus with signs of obstruction, which is present in more than 75% of cases, because the risk of complications increases with retention time. The endoscopist has myriad possibilities for finding the best and safest way to extract the foreign body.

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Markus F. Neurath

University of Erlangen-Nuremberg

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Martin Raithel

University of Erlangen-Nuremberg

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A Hagel

University of Erlangen-Nuremberg

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Timo Rath

University of Erlangen-Nuremberg

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Helmut Neumann

University of Erlangen-Nuremberg

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Michael Vieth

Otto-von-Guericke University Magdeburg

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H Albrecht

University of Erlangen-Nuremberg

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H Neumann

Otto-von-Guericke University Magdeburg

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Silke Löffler

University of Erlangen-Nuremberg

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Clemens Neufert

University of Erlangen-Nuremberg

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