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J Maiss

Publications and source records attributed to J Maiss.

16 recordsLinked to original sources
PubMed2006

The compactEASIE is a feasible training model for endoscopic novices: a prospective randomised trial.

BACKGROUND: The objective benefit of a training using the compact Erlangen Active Simulator for Interventional Endoscopy-simulator was demonstrated in two prospective educational trials (New York, France). The present study analysed whether endoscopic novices are able to reach a comparable level of endoscopic skills as in the above-described projects. METHODS: Twenty-seven endoscopic novices (medical students, first year residents) were enrolled in this prospective, randomised trial. The compact Erlangen Active Simulator for Interventional Endoscopy-simulator with an upper GI-organ package and blood perfusion system was used as a training tool. Basic evaluation of endoscopic skills was performed after a practical and theoretical course in diagnostic upper GI endoscopy followed by a stratified randomisation according to the rating in endoscopic skills into intensive (n=14) and control group (n=13). The intensive group was trained 12 times every second week over 7 months in 4 endoscopic disciplines (manual skills, injection therapy, haemoclip, band ligation) by skilled endoscopist (three trainees/simulator). Assessment was performed (single steps/overall) using an analogue scale from 1 to 10 (1=worst, 10=optimal performance) by expert tutors. The control group was not trained. Blinded final evaluation of all participants was performed in January 2003. RESULTS: We observed in all techniques applied a significant improvement of endoscopic skills and of the performance time in the intensive group compared to the control group (p<0.001). The comparison with the previous projects showed that the intensively trained novices achieved comparable levels of performance to the GI fellows in the New York and France Project (at least 80% of the median score in three out of four techniques). CONCLUSION: Endoscopic novices acquired notable skills in interventional endoscopy in the simulator by an intensive, periodical training using the compactEASIE.

Clinical Competence↗
PubMed2006

"Hemodynamic efficacy" of two endoscopic clip devices used in the treatment of bleeding vessels, tested in an experimental setting using the compact Erlangen Active Simulator for Interventional Endoscopy (compactEASIE) training model.

BACKGROUND AND STUDY AIMS: Hemoclip therapy is a well-established procedure in the treatment of gastrointestinal bleeding. Although new products are provided periodically by the industry, comparative investigations are lacking. We compared two different hemoclip devices in an experimental setting, assessing them using objective hemostatic parameters. MATERIALS AND METHODS: We compared two disposable clip devices (Olympus HX-200L-135 (n = 40) vs. Wilson-Cook Tri-Clip (n = 40)) in an experimental setting using the compact Erlangen Active Simulator for Interventional Endoscopy (compactEASIE) training model equipped with an upper gastrointestinal-organ package for bleeding simulation. This was a randomized, prospective, controlled trial. Four investigators with different levels of endoscopic experience applied ten hemoclip devices of each type to the spurting vessels, the clips allocated using a randomized list for each investigator. The efficacy of hemostasis was determined by continuous measurement of the pressure within the afferent vessel before and after clip application and calculation of the relative reduction of vessel diameter by the clip device. The system pressure was recorded over the period from 1 minute before to 1 minute after clip application. A secondary end point was a subjective assessment of the whole clip application procedure by the endoscopist and the assisting nurse, using a visual analog scale (0 - 100, with 100 representing the best experience). RESULTS: A total of 39/40 clips of each type were applied successfully. Both clip devices led to a significant increase in system pressure, representing significant relative reduction of vessel diameter (Olympus 5.4 +/- 7.5 %, p < 0.001; Cook 4.9 +/- 8.0 %, p < 0.001). Overall, there was no significant difference between the two devices ( P = 0.756). However, the investigator with the least experience in endoscopy (< 100 procedures) produced significantly inferior results compared with the other three investigators, who had performed between 2000 and 6000 procedures each ( P < 0.05). We found no evidence of a learning curve from the intra-observer results. The devices received good, but not significantly different, overall ratings by the endoscopists (Olympus 69 +/- 24 vs. Wilson-Cook 65 +/- 16) and by the assisting nurses (Olympus 77 +/- 9 vs. Wilson-Cook 70 +/- 22). CONCLUSIONS: Using an established cadaveric training model, no significant difference was found between the two types of hemoclip devices with respect to their "hemostatic efficacy". However, the experience of the endoscopist appears to play a major role in successful clip application. The use of a feedback mechanism in emergency endoscopy training, using continuous intravessel pressure monitoring, may substantially enhance the efficacy of training, resulting in a similar improvement in clinical results.

Cadaver↗
PubMed2006

Hemodynamic efficacy of the new resolution clip device in comparison with high-volume injection therapy in spurting bleeding: a prospective experimental trial using the compactEASIE simulator.

BACKGROUND AND STUDY AIMS: Peptic ulcers are the most frequent cause of gastrointestinal bleeding. The use of hemoclips has become established as an effective form of treatment in addition to injection therapy. However, hemoclips have not previously been compared with injection therapy in an experimental setting using objective parameters. MATERIALS AND METHODS: In a prospective, randomized, and controlled trial, the disposable Resolution hemoclip device (Boston Scientific, n = 40) was compared with conventional injection therapy (n = 40) in an experimental setting, using the compactEASIE simulator equipped with an upper gastrointestinal organ package to simulate bleeding. Four investigators with different levels of endoscopic experience participated in the study. On a randomized basis, each investigator treated 20 bleeding sites either by applying one clip (n = 10) or by carrying out high-volume four-quadrant injection (4 x 10 ml saline) of a spurting vessel. The efficacy of the hemostasis was assessed by continuous measurement of pressure within the afferent vessel before and after clip application or injection therapy and calculating the relative reduction in the vessel's diameter with each treatment method. The system pressure was recorded 1 min before and 1 min after treatment. The ease of application of each method was rated by the endoscopist and by the assisting nurse using a visual analogue scale (0 - 100, with 100 being best). RESULTS: All of the 40 hemoclipping and injection treatments were carried out successfully. Both methods led to a significant increase in peak pressure (Resolution clip 71.8 +/- 66.8 mm Hg, P < 0.001; injection 71.9 +/- 53.8 mm Hg, P < 0.001), representing a significant relative reduction in the vessel diameter. There were no significant differences in peak pressure between the two treatments ( P = 0.995). The mean increase in pressure during the first minute after the intervention (clip 49.3 +/- 67.0 mm Hg vs. injection 19.9 +/- 41.6 mm Hg) was significantly greater with the hemoclipping procedure ( P = 0.021). More experienced investigators achieved a greater increase in system pressure, but the difference was not significant. The assessments of the ease of application by the assistants (84 +/- 13) and endoscopists (86 +/- 16) did not show any significant differences ( P = 0.402) for the clipping device. CONCLUSIONS: No significant differences between the two treatment methods were detected with regard to the immediate efficacy of hemostasis. However, long-term hemostasis was better with hemoclipping. The endoscopist's level of experience also appears to play a role, particularly when hemoclips are used.

Animals↗
PubMed2005

Objective benefit of a 1-day training course in endoscopic hemostasis using the "compactEASIE" endoscopy simulator.

BACKGROUND AND STUDY AIMS: The Erlangen Active Simulator for Interventional Endoscopy (EASIE) was introduced in 1997 as a training model for interventional endoscopy. Objective evidence of the benefits of training with this model has not previously been published. As part of two long-term projects, the benefits of a 1-day training course with the "compactEASIE" simulator were evaluated. MATERIALS AND METHODS: Fourteen American and 18 French gastroenterology fellows were enrolled. These fellows were participants in the intensive groups performing training in endoscopic hemostasis, with a total number of 28 fellows in New York and 36 in France. Gastrointestinal endoscopy faculty members in New York and France evaluated and timed the fellows in four disciplines to establish baseline skills (manual skills; injection and coagulation; Hemoclip application; and variceal ligation) with the compactEASIE simulator. The trainees were reevaluated after an intensive 1-day course (with two or three fellows and one instructor per station), also including preparation and assistance for each procedure. The assessment (overall and parts) was done by expert tutors using an ordinal scale ranging from 1 to 10 (1 = poorest, 10 = best), recording also mistakes and performance time. The compactEASIE simulator, equipped with an upper gastrointestinal organ package and an artificial blood perfusion system, was used as the training tool. RESULTS: A highly significant improvement ( P < or = 0.001) was observed in the performance of all endoscopic techniques. A significant reduction in performance time was also observed with three of the four endoscopic techniques. Successful hemostasis was significantly improved in two out of three techniques. CONCLUSIONS: A 1-day training course on endoscopic hemostasis using the compactEASIE simulator is capable of improving the performance of hemostasis procedures. Long-term effects of repeated training sessions are currently subject of collaborative studies in New York and France.

Clinical Competence↗
PubMed2004

Successful laserlithotripsy in Bouveret's syndrome using a new frequency doubled doublepulse Nd:YAG laser (FREDDY).

Gastric outlet obstruction as a result of gallstone (Bouveret syndrome) is a rare but serious complication of cholelithiasis. In many cases, surgery has been conducted for treatment. In recent years, minimal invasive treatment modalities (e.g. shockwave lithotripsy) have been shown to be effective in some of those patients. Laserlithotripsy has so far been described in two cases with a Rhodamine-6G dye laser. We present the case of a 90-year-old woman with duodenal obstruction due to a huge gallstone. The patient was referred to our hospital because attempts at endoscopic extraction and extracorporeal shockwave lithotripsy had failed. The man was treated successfully in just one session with a new cost-efficient frequency doubled doublepulse Nd:YAG laser (FREDDY) using a total of 5726 laser pulses (120 mJ pulse energy, 10 Hz pulse repetition rate) and recovered rapidly. Laserlithotripsy can be considered an effective non-invasive therapeutic alternative to surgical treatment in Bouveret's syndrome, especially in old or high-risk patients.

Aged↗
PubMed2004

The compact Erlangen Active Simulator for Interventional Endoscopy: a prospective comparison in structured team-training courses on "endoscopic hemostasis" for doctors and nurses to the "Endo-Trainer" model.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Clinical Competence↗
PubMed2003

Management of difficult common bile duct stones.

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.

Choledocholithiasis↗
PubMed2003

Endoscopic antireflux treatment: fact, fiction or future?

Medical therapy with proton pump inhibitors (PPIs), aside from surgery, is the established and most effective treatment approach for chronic gastroesophageal reflux disease (GERD). Recently developed endoscopic antireflux procedures may be an alternative for a subset of patients with uncomplicated, mild GERD. Given the perioperative morbidity and mortality risk of laparoscopic fundoplication, less invasive semi-surgical and flexible endoscopic techniques may be an option for patients who cannot or wish not to take long-term medication. These clinical procedures include endoscopic suturing devices, focal radiofrequency coagulation in the cardia and bioimplants. While many of these techniques have shown good results in preliminary studies, long-term results are not yet available and therefore all such procedures have to be considered experimental. Their effectiveness will need to be compared with that of established treatment forms.

Electrocoagulation↗
PubMed2002

Tele-endoscopy: influence of data compression, bandwidth and simulated impairments on the usability of real-time digital video endoscopy transmissions for medical diagnoses.

BACKGROUND AND STUDY AIMS: Real-time digital video transmission (rtDVT) at an acceptable quality through networks has been possible for several years. This technique can be used for telemedical applications, such as tele-endoscopy. The hypotheses of the present study were that the quality of real-time DVT depends on the technical equipment used, and that the resulting image quality influences the usability of the system for diagnostic purposes. MATERIALS AND METHODS: An experimental network was established between two German referral endoscopy centers, using the Asynchronous Transfer Mode (ATM) protocol. At first, rtDVTs of routine gastrointestinal video endoscopies were transferred through the network for prospective evaluation of the feasibility of the technical equipment and its usability for diagnostic tele-endoscopy, based on the video image quality. Secondly, the image quality and usability for correct telemedical diagnosis were evaluated prospectively in a double-blind experimental setting in relation to variations in the methods of data compression used, transmission bandwidths, and simulated transmission errors. Fourteen endoscopists evaluated 27 variations of an endoscopic video sequence. RESULTS: Compression with the Moving Picture Expert Group 2 (MPEG2 [4 : 2 : 2]) standard, the ATM protocol, and a bandwidth of 40 megabits per second (Mb/s) were used successfully in 40 routine tele-endoscopies for practical evaluation. Doctors were able to handle the system with ease, and its availability was 100%. There were no detectable differences between the original video image and the transferred image, and the images were usable for diagnosis in all cases. The set-up used clinically was therefore considered to provide the optimal conditions for comparisons in the experimental part of the study. Experimentally, any technical variation was found to cause a reduction in the overall image quality and hence a reduction in diagnostic usability: compression algorithm (MPEG2 [4 : 2 : 2] vs. others: P = 0.001), bandwidth (> or = 8 vs. < 8 Mb/s: P = 0.001), and error rate (10 (-8) vs. 10 (-7): P = 0.001). CONCLUSIONS: rtDVT using MPEG2 [4 : 2 : 2] compression and a bandwidth of 40 Mb/s did not effectively differ from the original video images in routine tele-endoscopy. The qualitative requirements in diagnostic video endoscopy, however, are obviously much higher than previously assumed, since experienced endoscopists detected a loss of image quality and a reduction in diagnostic usability with any reduction in the technical specification. Modern methods of data compression, broadband networks and a network protocol with good quality-of-service guarantees are therefore prerequisites for diagnostic rtDVT.

Algorithms↗
PubMed1998

Laser lithotripsy of difficult bile duct stones: results in 60 patients using a rhodamine 6G dye laser with optical stone tissue detection system.

INTRODUCTION: Laser lithotripsy of bile duct stones has become a widely accepted endoscopic treatment modality for giant, impacted, or very hard stones. The procedure is usually carried out under direct endoscopic control in view of the potential risk of bile duct injuries in "blind" laser application. AIMS: To investigate the use of a rhodamine 6G laser lithotriptor with an integrated optical stone tissue detection system (oSTDS). METHODS: From 1 September 1991 to 7 March 1997, 60 patients with giant or impacted common bile duct stones refractory to endoscopic papillotomy stone extraction, and mechanical lithotripsy were treated via the endoscopic retrograde route using a rhodamine 6G dye laser (595 nm, 2.5 micros, 80-150 mJ pp, Lithognost Telemit/Baasel Corp., Germany) with integrated oSTDS. In case of tissue contact oSTDS cuts off the laser pulse after 190 ns (transmission of 5-8% of the total pulse energy). 47 patients (78.3%) were subjected to x ray targeting (oSTDS) alone, five (8.3%) to choledochoscope targeting alone, and eight (13.3%) to both techniques. RESULTS: At the end of treatment 52 (87%) patients were completely stone-free. The only major complications included transient haemobilia, cholangitis, and pancreatitis in five patients. All five were successfully treated by conservative methods. CONCLUSIONS: Laser lithotripsy using the described rhodamine 6G dye laser with oSTDS seems to be safe and effective and allows "blind" fragmentation of difficult common bile duct stones under radiological control only.

Adult↗