Steffen M. Muehldorfer

Endoscopic light-induced autofluorescence spectroscopy for the diagnosis of colorectal cancer and adenoma.

To evaluate the new, bio-optical method of light-induced autofluorescence spectroscopy for the endoscopic in-vivo diagnosis of (pre)-cancerous lesions of the colorectum, 311 endogenous fluorescence spectra were obtained from normal, adenomatous and cancerous colorectal tissue in 11 patients with cancer, six patients with familial adenomatous polyposis, and six patients with multiple adenomatous polyps. A light source delivered either white or violet-blue light for excitation of tissue autofluorescence via a flexible endoscope. Endogenous fluorescence spectra emitted by the tissue were picked up with a fiberoptic probe and analysed with a spectrograph. Biopsies were taken for definitive classification of the spectra. Rectal cancer (n=11) as well as adenomas with severe dysplasia (n=19) showed specific differences between the emitted fluorescence spectra as compared with normal mucosa and hyperplastic polyps. Having applied a mathematical algorithm to the spectra, a sensitivity of 96% and a specificity of 93% were obtained for the diagnosis of rectal cancer. The equivalent values for the diagnosis of dysplastic ademomas were 98 and 89%, respectively. Light-induced autofluorescence spectroscopy is a new and promising bio-optical procedure for the endoscopic in-vivo diagnosis of colorectal cancer and dysplasia.

Evaluation of sensitivity and inter- and intra-observer variability in the detection of intestinal metaplasia and dysplasia in Barrett's esophagus with enhanced magnification endoscopy

Objective. Magnification endoscopy with acetic acid or dye for diagnosis of Barretts esophagus is presently undergoing clinical evaluation. Current studies report good accuracy in predicting specialized intestinal metaplasia. To date, however, there is no definitive information on the inter- and intra-observer variability of these methods applied to the diagnosis of normal and dysplastic Barretts mucosa. Material and methods. Sixty patients with endoscopically suspected Barretts esophagus were investigated prospectively with the zoom endoscope after contrast enhancement of the mucosa with 1.5% acetic acid. Two hundred and twenty-three enlarged and histologically investigated areas of gastric, cardiac, normal and dysplastic Barretts mucosa were photodocumented and in randomized sequence presented to 4 endoscopists in a blinded manner (2 with and 2 without experience of zoom endoscopy for evaluation). The reference for the first evaluation (A1) was standard endoscopic photographs of the respective, histologically confirmed mucosal entity. In a second evaluation (A2), the pictures were again interpreted by the same blinded investigators, but this time a modified pit-pattern classification as proposed by Sharma et al. was employed as the evaluation reference. Results. The diagnostic sensitivity for specialized intestinal metaplasia and dysplasia in Barretts esophagus calculated for the A1 evaluation ranged – investigator dependently – from 54.9% to 80.7% and for A2 from 42.2% to 81.5%. The inter- and intra-observer variability for the evaluation procedure A1 and A2 was high (all kappa values <0.4). In particular, the inexperienced investigators demonstrated high intra-observer variability and low sensitivity in comparison with the experienced investigators. Conclusions. The diagnosis of Barretts mucosa using enhanced magnification endoscopy after acetic acid instillation is associated with a high level of interobserver variability. One reason is a frequent mismatch between cardiac mucosa and non-dysplastic Barretts mucosa.

High- and low-compliance balloon dilators in patients with achalasia: a randomized prospective comparative trial

BACKGROUND Pneumatic dilation is the most effective nonsurgical method for treatment of achalasia. The most serious complication of this procedure is esophageal perforation, which occurs in about 5% of cases. We completed a randomized prospective comparative trial with a high-compliance latex balloon (HCB) mounted on an endoscope (40 mm maximum distension diameter, 6 psi inflation pressure) and a low-compliance balloon (LCB) (35 mm, 20 psi) with respect to efficacy and side effects. METHODS Twenty-five patients (13 treated with HCB, 12 treated with LCB) were included. The symptom score was assessed both before and after dilation, biannually, for up to 2 years, and complications were graded for severity. All dilations lasted for 3 minutes and were performed under direct endoscopic control. Patients were randomly assigned to the two different balloon types. RESULTS One perforation was observed in the LCB group (not significant between HCB and LCB). Superficial mucosal tears appeared in 40% of all dilations. Initial dilation treatment was successful in 20 of 25 (80%) patients (10 of 13 HCB, 10 of 12 LCB). There were no significant differences in the median pretreatment and post-treatment symptom scores. Three patients required repeated dilations during the observation period. They were treated with the competing balloon system and showed no difference compared with the initial posttreatment symptom score. CONCLUSIONS No significant difference could be demonstrated between the HCB and LCB system as far as the complication rate and the clinical outcome are concerned. In consequence, both systems appear equally effective, although the endoscope-mounted system (HCB) can be handled more easily.

Gastric involvement in progressive systemic sclerosis: electrogastrographic and sonographic findings.

OBJECTIVE To determine whether electrogastrography (EGG) can discern sonographically demonstrated motility disorders in patients with progressive systemic sclerosis (SSc) and to evaluate EGG as a possible diagnostic tool. DESIGN Prospective study with control group and testing for reliability. SUBJECTS 15 SSc patients [women aged 33-70 years (mean 53.3 years)] and 15 healthy volunteers. METHODS Bipolar cutaneous EGG was recorded to obtain the following parameters: period dominant frequency (PDF), percentage of gastric dysrhythmia and normogastria (defined as 2-4/min), period dominant power (PDP) and its change after a standardized meal of 500 kcal (2093 kJ), and instability coefficients of dominant frequency and power (DFIC, DPIC). Simultaneously, real-time sonography was performed in the aortomesenteric plane (3.5-MHz curved-array probe). In 10 patients and 13 control subjects, the distance from the anterior wall of the gastric antrum to the abdominal skin was measured. RESULTS Three patients (20%) showed hypomotility of the gastric antrum sonographically. The percentage of bradygastria was significantly lower in these patients, but the PDF, DFIC and DPIC values were not significantly different. The distance between the cutaneous electrodes and the antrum bore a greater relationship to the PDP values than did the sonographically demonstrated number of gastric contractions. CONCLUSIONS Although cutaneous EGG can be performed in SSc patients without apparent derangement in frequency and stability of the signal, it offers no advantage over sonography in diagnosis and follow-up.

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 Bouverets syndrome, especially in old or high‐risk patients.

4619 Hemorrhage after endoscopic sphincterotomy: risk factors and endoscopic managenent - final results of a prospective study.

To determine risk factors (RF) for hemorrhage after endoscopic sphincterotomy (EST) and to evaluate the outcome of therapeutic modalities. METHODS: In all consecutive EST procedures between 09/94 and 12/98 indications, techniques, success, complications of EST, and possible RF for hemorrhage were evaluated prospectively. Pts. were followed up by physical examination and blood samples at 4, 24 and 48 hours after EST. Complications were classified according to commonly accepted criteria (Gastrointest Endosc 1991: 338). Risk factor analysis was performed using univariate methods. RESULTS: In 815 pts. (53.3% m, 46.7% f, 61±17 y); complications occured in 9.9% (81/815; 69 mild-moderate; 11 severe; 4 fatal). Bleeding during the procedure was seen in 50 pt. (self-limiting in 35 cases, successful injection therapy in 15 pt). The incidence of hemorrhage (drop of hemoglobin of at least 2 g/dl and clinical signs of hemorrhage) was 1.6% (14/815; 7 mild-moderate; 5 severe; 2 fatal). Hemorrhage was detected only in 2 pt., who showed bleeding during EST (both with prior injection therapy), and in 12 pt. without signs of bleeding during EST. The clinical onset of hemorrhage was within 4 hours after EST in 5 pt., within 2 days in 4 pt., and within 4 to 10 days in 5 pt. Univariate analysis obtained 2 RF for hemorrhage: coagulopathy (thrombocytes

4622 The endoscopist is the major risk factor for complications of endoscopc sphincterotomy: final results of a prospective study.

To determine risk factors (RF) for complications of endoscopic sphincterotomy (EST). METHODS: In all consecutive EST procedures between 09/94 and 12/98 indications, techniques, success, complications of EST and possible RF were evaluated prospectively. Pts. were followed up by physical examination and blood samples at 4, 24 and 48 hours after EST. Complications were classified according to commonly accepted criteria (Gastrointest Endosc 1991: 338). Analysis of RF was performed by uni- and multivariate methods. RESULTS: In 815 pts. (53.3% m, 46.7% f, 61±17 y); complications occured in 9.9% (81/815; 69 mild-moderate; 11 severe; 4 fatal): Pancreatitis: 6.4% (52/815; 48 mild-moderate; 4 severe; 0 fatal), Hemorrhage: 1.6% (14/815; 7 mild-moderate; 5 severe; 2 fatal), infections 1.7% (15/815; 11 mild-moderate; 2 severe; 2 fatal), perforation 0.2% (2/815; 2 mild-moderate). Others 0.1% (1/815; 1 mild). Multivariate analysis obtained a frequency of ≤40 EST/y as the only RF for complications in total (15.2% vs. 7.8%, p=0.002), and diabetes mellitus as independent protective factor (5.1% vs. 11.3%, p=0.02). No other variables reached significant levels in univariate analysis regarding complications in total. Coagulopathy (thrombocytes

4615 Prevention of acute post-ercp pancreatitis with heparin? final results of a prospective study on risk factors for ap.

Explorative analysis obtained a very low incidence of AP in patients who received heparin prior to ERCP with EST. Experimental data showed that heparin has anti-inflammatory effects, improves pancreatic microcirculation during AP and inhibits pancreatic proteases. METHODS: Potential risk factors for AP were prospectively analysed in all consecutive ERCP with EST between 09/94 and 12/98. Pts. were followed up by physical examination and blood samples at 4, 24 and 48 hours af-ter EST. Complications were classified according to commonly accepted criteria (Gastrointest Endosc 1991: 338). Confirmative analysis of RF for AP was performed by uni- and multivariate methods, and the incidence of AP was compared between pts. who received heparin (HEP) and pts. without heparin (CON; control) considering known and suspected confounding variables (RF-analysis for AP). RESULTS: 815 pts. (53.3% m, 46.7% f, 61±17 y); complications 9.9% (81/815; 69 mild-moderate; 11 severe; 4 fatal). The incidence of AP was 6.4% (52/815; 48 mild-moderate; 4 severe; 0 fatal). Heparin was administered in 33.0% (269/815). Multivariate analysis identified 4 independent RF for AP: endoscopist-frequency ≤ 40EST/y (11.8% vs. 4.2%, p=0.002), female sex (9.2% vs. 3.9%, p=0.005), SOD (37.5% vs. 6.1%; p=0.011), pancreas divisum (18.7% vs. 5.9%, p=0.013), and one independent protective factor: heparin administration (3.3% vs. 7.9%; p=0.002). Additionally, prior laparoscopic cholecystectomy (14.3% vs. 6.0%, p=0.044) and pancreatic cannulation (7.8% vs. 4.3%, p=0.057) univariately showed an increased risk for AP. Pt.-age

4739 Removal of peg-tubes by cutting-the-tube: shortand long-term complications.

Background: For removal of PEG-tubes, two different techniques exist: 1. an endoscopic approach and 2. the natural passage after cutting the tube at skin level. Although the second possibility is preferred by most of the patients, complications like bowel obstruction with the need of surgery have been reported. Additionally, the long-term complications of this procedure are unknown. Methods:We performed a combined retrospective and prospective study to investigate the complications of removal of PEG-tubes by cutting. Duration of tube-passage was documented, and if natural passage was not noticed by the patient, an x-ray-examination was offered. Additionally, the further outcome of the patients was evaluated. Every patient was advised to drink at least 2000mls fluid per day, and to ensure deliberate oral food intake Results: Of 62 patients investigated (30 prospective, 32 retrospective; age: 26- 77 years, mean: 46.5 years; 82% male, 18% female; indication for PEG: Headand-Neck-Tumor: 89%, Esophagus-Tumor: 3%, Others: 8%), only 3 exhibited complications: 1 patient had abdominal pain until passage of the PEG after 4 days, and two had gastro-cutaneuos fistulas for 6 and 12 months respectively. Reasons for PEG-removal was sufficient oral intake without further need for the PEG-tube in 59/62 (95%) patients, and PEG-defect in 3 patients (5%) resulting in Button-PEG placement. Passage was noted only by 34/62 patients (55%) with a mean passage-time of 2.4 days (range: 0.5-13 days). In 11 of 28 patients, who did not notice PEG-passage, an x-ray was performed for control, but PEG-tubes could not found in any of the plain abdominal radiographs. After a mean follow-up of 38 months (range: 1-94 months), 46/59 patients (78%) are still doing well without PEG, 7 (12%) had died (4 because of the underlying disease, 3 because of other illnesses), and 6 (10%) needed a PEG-tube again because of inability of sufficient oral intake. Conclusions: Cutting-the-tube is not only easy to perform, it also seems to be safe, even if no passage of the tube is noticed by the patient. Providing bowel movements is essential to avoid bowel obstruction. In the long-term, 10% of the patients need a PEG-tube again. Therefore, indication for PEG-removal should be considered very carefully.