Self-expanding metal stents for palliation of stenosing tumors of the esophagus and cardia: a critical review.
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Cardia↗
Biomedical subjects
C Ell
Publications and source records attributed to C Ell.
Invasive carcinoma in colorectal adenomas: multivariate analysis of patient and adenoma characteristics.
BACKGROUND AND STUDY AIMS: The risk of invasive carcinoma developing in colorectal adenomas is influenced by a number of characteristics, relating both to the patients and to the adenomas, and by the composition of the sample analyzed. The aim of the present study was use a multivariate analysis to investigate the risk of invasive carcinoma in endoscopically and surgically removed adenomas. PATIENTS AND METHODS: Between 1978 and 1993, more than 20,000 polyps were prospectively documented at the Erlangen Registry of Colorectal Polyps. A multivariate analysis of 11,188 adenomas detected at the first total colonoscopy was carried out in order to investigate the risks associated with size and site--both of which can be assessed by endoscopic inspection alone- and the extent to which these may be modified by other patient and adenoma characteristics, with an influence on the risk of invasive carcinoma in colorectal adenomas. RESULTS: The size of the adenoma proved to be the most important influencing factor. Invasive carcinoma was never found in 5027 small adenomas (< or = 5 mm). Adenomas in the right colon had a lower risk than those in the left colon or rectum. But with increasing adenoma size, the malignancy rate showed a right-sided shift, with a significant interactive effect of size and right-sided location. However, the risk determined by the size and site of the adenoma was significantly modified by a number of patient and adenoma characteristics, including histological type, presence of multiple adenomas, and patient age and sex. CONCLUSIONS: The risk of invasive carcinoma in colorectal adenomas can only be adequately described by a complex model of the interactive effects of patient and adenoma characteristics on the main factors of size and site.
Adenoma↗
[Research activity and research quality of German gastroenterologists reflected by citation indices].
UNLABELLED: The objective judgement of the activity and research quality is a central aim of the scientific community. Citation indices as valid and objective parameters have been already used in many disciplines for that purpose. The following paper describes and analyzes the citation indices of all members of the German Society of Gastroenterology, who received lectures degree (habilitation; equivalent to PhD). METHODS: Citation indices of 376 habilitated German gastroenterologists were determined for the year 1992. Using the individual citation indices of all persons a ranking curve was calculated and compared with the ranking curve of 1987, which was calculated in the same way. Furthermore, representative groups of habilitated gastroenterologists who were cited often (> 30 citations/year), moderate or nil were evaluated concerning their citation indices during the time interval between the year of habilitation and 1992. RESULTS: About 40% of all tested gastroenterologists were not or only very rare (0-2 citations/year) cited in the world literature. Only 15% reached citation rates over 30/year. No relevant differences were found between the ranking curves of 1992 and 1987. Gastroenterologists with high citation rates in 1992 had also high indices at the time of their habilitation; those with low or no citations in the year 1992, had also low citation rates at the time of their habilitation (p < 0.05). CONCLUSIONS: More than 1/3 of the habilitated German gastroenterologists are 1992 not seriously registered in the scientific world literature. Only a minority of gastroenterologists shows international acceptable high citation rates. The determination of individual citation indices together with the ranking curve of the whole group of gastroenterologists appears to be suitable to judge the research activity of an individual gastroenterologist and may also serve as useful information about individual research potential in the future.
Cross-Cultural Comparison↗
[Morphological changes in human colon carcinoma after chemotherapy with 5-fluorouracil--a study in the nude mouse model].
Colorectal cancer represents one of the most important challenges in the field of cancer chemotherapy. 5-fluorouracil (5-FU) is used as the first-choice chemotherapeutic agent in the treatment of advanced gastrointestinal cancer. Despite this fact very little is known about the morphological changes of colon carcinoma after treatment with 5-FU. Thymusaplastic nude mice (n = 59) with subcutaneously heterotransplanted human coloncarcinoma (tubulo-papillary adenocarcinoma, grade II-III) were treated with 5-FU (40 mg/kg/body weight i. p. for five days). The animals were sacrificed, tumors were removed at 0 h, 24 h, 36 h, 48 h, 54 h, 60 h, 66 h, 72 h, 94 h, 118 h, 240 h after chemotherapy and the tumor tissue was embedded for light-microscopic and ultrastructural examination. Hydropic mitochondria and cytoplasmatic vacuoles were observed in tumor cells as early as 0 h after chemotherapy. These changes displayed a focal pattern. Damaged tumor tissue was surrounded by tumor cells with intact ultrastructure. In some regions tumor cells were separated from the basal membrane and showed signs of necrosis. These focal changes within the tumor tissue were observed from 0-240 h after treatment. Tumor capillaries did not show any damage. Treatment with 5-FU led to focal cytotoxic effects in the tumor. The remaining intact vascular system of the tumor may be a target for new therapy modalities.
Adenocarcinoma, Papillary↗
[Interventional endoscopic therapy of chronic pancreatitis].
BACKGROUND AND AIM: Complications in chronic pancreatitis, such as duct occlusion due to stenosis or stones can be treated by interventional endoscopic procedures. The benefit of such procedures and the effect on the clinical course is still under debate. Therefore, it was the aim of this study to analyze the effect of endoscopic interventional procedures in more detail with respect to technical and clinical benefit. PATIENTS AND METHODS: 100 patients with chronic pancreatitis (cP) were studied retrospectively. In 58 patients an indication for interventional endoscopic therapy was given (45 +/- 12 yrs; 46 M, 12 F; cP 1 degree: n = 1, cP II degree: n = 8, cP III degree: n = 49). The patients were allocated to three groups: stenosis (n = 18), pancreatic duct stones (n = 18) and stenosis and pancreatic duct stones (n = 20). In two patients no visualization of the main pancreatic duct was performed due to cholestasis that was treated primarily. In total, 295 endoscopic procedures were performed (EPT, duct dilatation, plastic endoprothesis, ESWL, mechanical lithotripsy). Technical success was 95%. All stenoses could be dilated or bridged by plastic stents. Fragmentation of main pancreatic duct stones was achieved in 92%. The overall complication rate of all 319 endoscopies (fever, bleeding, stent dislocation) was 15.8%. Five patients had to undergo surgery, however, not as a direct consequence of complications from or unability of endoscopic procedures. 86% of the patients reported complete pain relief after the endoscopic-interventional procedures and 62% during the follow-up interval (7.4 +/- 6.3 months). 59% of the patients with weight loss and 58% of the patients with initially stable weight experienced a weight gain following endoscopic-interventional therapy. Individual patients showed improvement of endocrine or exocrine pancreatic function. 82% of the patients did not require inhouse treatment or emergency admission to the hospital whereas three admissions on average were recorded prior to endoscopic interventional treatment. Therefore, we conclude that a subset of patients does benefit from endoscopic interventional therapy of complications of chronic pancreatitis. However, a controlled prospective study is still mandatory.
Adolescent↗
[Prospective study of diagnosis, therapy and follow-up of acute gastrointestinal hemorrhage in 397 patients].
The mortality of acute GI hemorrhage in the literature varies considerably, depending on the study design and quality of the data evaluated. We therefore conducted a prospective study over 2.5 years of 397 patients with suspected acute GI hemorrhage at the University hospital of Erlangen for internal quality control. In 99% of cases diagnostic endoscopy identified one or more bleeding sources. 46% of the patients bled from duodenal or gastric ulcers, 21% from esophageal or gastric varices and 33% from other sources. 228 of the 397 patients (57%) were initially treated endoscopically, 76 patients (19%) experienced a recurrence of bleeding. Patients older than 60 years of age with a hemoglobin below 8 g/dl had a significantly higher rate of recurrent bleeding. The rate of complications during the hospital stay was 22% (n = 87), in-hospital mortality 17% (n = 68). The rates of recurrent bleeding (28 vs. 20%), complications (24 vs. 18%) and mortality (20 vs. 14%) were significantly higher for bleeding varices than for peptic ulcers. Patients with other causes of acute GI hemorrhage developed a recurrence of bleeding in 13%, complications in 26% and had a mortality rate of 19%. Bleeding varices as well as bleeding peptic ulcers and other causes of acute GI hemorrhage still have a high mortality and require intensive medical surveillance besides diagnostic and therapeutic endoscopy.
Acute Disease↗
[Cholestasis--therapy].
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Cholestasis, Extrahepatic↗
[1995 gastroenterology update--I].
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Clinical Trials as Topic↗
[1995 gastroenterology update--II].
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Biliary Tract Diseases↗
[Technical and clinical success with extracorporeal shockwave lithotripsy in pancreatic duct calculi].
BACKGROUND: Chronic pancreatitis is often complicated by concrements obstructing the main pancreatic duct. Duct obstruction is discussed as potential mechanism responsible for recurrent and persistent pain. PATIENTS AND METHODS: 75 symptomatic patients (15 female, 60 male; 46 +/- 12 years) with stones in the main pancreatic duct (solitary n = 23; multiple n = 52) primarily not endoscopically extractable even after sphincterotomy of the pancreatic orifice were treated by means of a piezoelectric lithotripter (Piezolith 2500). Fragmentation and stone clearance were documented by ERP. The clinical benefit was evaluated in 35 patients (9 female, 26 male; 45 +/- 12 years) followed up meanwhile for more than 12 (29 +/- 14) months. RESULTS: After 3 +/- 2 (1 to 10) ESWL-sessions/patient the concrements were fragmented successfully in 80% of the patients. Focussing of the stones was achieved sonographically (15%), fluoroscopically (45%) or using both imaging techniques (40%). In total, 61% of the patients became stone free, 44% spontaneously, in further 17% all remaining fragments could be removed endoscopically. In 39% of the patients only a partial extraction was achieved. Severe complications due to shockwave application did not occur. The majority of the patients (stonefree n = 22, remaining fragments n = 13) followed up > or = 12 months kept free of pain (51%) or reported on pain relief (26%). Nine patients developed 13 recurrent calculi, which were again treated successfully by interventional measures in 8/9 patients. CONCLUSIONS: The data confirm the value of extracorporeal shockwave lithotripsy as an important tool in the interventional therapy of chronic pancreatitis. Even if recurrent calculi may occur, the majority of patients will experience at least a medium-term profit by those measures due to pain relief.
Adult↗
[Gastroenterology update 1995--II].
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Diagnosis, Differential↗
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.
Adult↗
Biophysical effects of high-energy pulsed ultrasound on human cells.
Human benign and malignant cells of different human origin (pancreas, liver, kidney, pharynx, tongue, lip) were exposed to high-energy pulsed ultrasound (HEPUS) in vitro to evaluate the effects of various physical parameters and sonication conditions on cell viability. This included the number of pulses, focal pressure, pulse repetition rate, pulse shape, cell suspension volume, water level of the basin and cell density. Cell viability was found to depend significantly on the number of pulses (exponential), the focal pressure (linear) and the pulse repetition rate (minimum at 1 Hz). Other parameters showed no marked influence. Furthermore, electron microscopy revealed intracellular damage, and proliferation rates of cells surviving sonication were normal after HEPUS exposure. The experimental piezoelectric ultrasound transducer used in the experiments generated oscillating bipolar pulses with high negative pressure amplitudes. Measurements were made of the pulse shape and ultrasonic field of the experimental device and of a conventional lithotripter for comparison.
Biopsy↗
Colon decompression using an anatomically adapted, large-caliber decompression probe.
Intestinal pseudo-obstruction, paralytic (e.g. postoperative or drug-induced) hyperdistension of the large bowel and colonic stenosis often require endoscopic decompression. The decompression probes currently available have the disadvantage of an insufficiently large diameter or inadequate adaptation to the given anatomic configuration of colon, or both. A new decompression probe system consisting of a guide wire, a 12-Fr polyethylene guide catheter, and a 24-Fr polyurethane decompression probe, is presented and two cases are described. The probe was tested in a pilot study in 16 patients. In all patients, implantation was successfully performed without complications. No undesired dislocation was observed. The introduction time varied between four and 16 minutes. Clinically successful decompression was achieved in 14 of the 16 patients.
Aged↗
Self-expanding metal stents for palliation of malignant obstruction in the upper gastrointestinal tract. Comparative assessment of three stent types implemented in 96 implantations.
Self-expanding metal stents provide a new option for the palliative treatment of malignant stenoses from tumors of the esophagus. Our present study provides a comparative assessment of clinical experience gained consecutively in the implementation of three stent versions in a total of 87 patients and 96 implantations. Thirty-one Wallstents (Scheider, Lusanne, Switzerland) (five coated) were implanted in 23 patients, 35 Ultraflex stents (Boston Scientific, Boston, MA, U.S.A.) (uncoated) in another 34 patients, and 30 Gianturco-Z stents (Cook, Winston-Salem, NC, U.S.A.) (all coated) in a group of 30 patients. In the three patient groups there were no significant differences as to the degree of dysphagia, number of pretreatments, length of the tumor stenosis, tumor location, or histological classification. Seven patients who had been treated with Gianturco-Z stents presented with an esophagorespiratory fistula. Technically, all 96 implantation procedures were successful. Complete sealing of the fistulas was verified by radiography in all patients who had developed fistulas. Severe early complications in the form of stent migration were encountered in only three of 96 implantations (3%). Within the early period after stent placement in five patients of the Wallstent group (22%), 13 patients of the Ultraflex group (37%), and three patients of the Gianturco group (10%), retreatments were necessary due to stent dislocation and/or insufficient stent expansion. The degree of dysphagia improved distinctly and with a comparable development in all three patient groups. The rate of reintervention (percentage of patients) due to major and minor problems in the follow-up period amounted to 43% (Wallstents), 35% (Ultraflex stents), and 21% (Gianturco-Z stents). In view of the low number of complications (3%) in the early stage of implantation, self-expanding metal stents provide an improved approach for palliative therapy of malignant stenoses of the esophagus. Nevertheless, further technological improvements are necessary to reduce the great frequency of unavoidable reinterventions (20-43%) in the follow-up period.
Adult↗
Correlation of polypoid lesions in the distal colorectum and proximal colon in asymptomatic screening subjects.
OBJECTIVE: Knowledge of a possible correlation between distal polyps found at screening sigmoidoscopy and proximal colonic lesions is important for deciding whether to perform total colonoscopy or not. PATIENTS: A prospective analysis of 2439 consecutive patients with colorectal polyps. Of these, 304 were asymptomatic subjects who underwent complete colonoscopy for screening and were found to have adenomatous or hyperplastic polyps in the distal colorectum. RESULTS: Ten (15%) out of 65 patients with distal hyperplastic polyps only and 86 (36%) out of 239 with distal adenomatous polyps were found to have adenomatous polyps in the proximal colon as well (P < 0.001). The frequency of synchronous proximal adenomas in patients with small (< or = 5 mm) or large distal adenomas (> 5 mm) was comparable (37% and 35%, respectively). However, patients with small distal adenomas had significantly smaller proximal adenomas (P = 0.004) containing less villous component (P = 0.017) than those with large distal adenomas. Neither the patient's age nor the presence of multiple distal adenomas increased the prevalence of proximal adenomas. CONCLUSION: Hyperplastic polyps found on rectosigmoidoscopy do not indicate a need for a complete colorectal examination, as 15% of patients with distal hyperplastic polyps will have proximal adenomatous polyps, a figure that is comparable with that of asymptomatic patients having no distal polyps, either hyperplastic or adenomatous. When only small distal adenomas are found at screening sigmoidoscopy in asymptomatic persons the decision to do a total colonoscopy should be based on individual considerations, as in such cases only small polyps are to be expected in the proximal colon.
Adenomatous Polyps↗
[Photodynamic therapy of dysplasia and early cancer of the esophagus].
Photodynamic therapy (PDT) is a new local, endoscopically controlled therapeutic concept based on the selective sensitization of malignant and precancerous lesions prior to light-induced tissue destruction. The first therapeutic experiences with the conventional photosensitizer dihematopor-phyrineter in the treatment of Barrett's esophagus without or with severe dysplasia and mucosal carcinomas of the esophagus demonstrate the efficacy and the curative potential of photodynamic therapy. The unwanted skin photosensitivity and only relative selectivity of the haematoporphyrins however, are somehow unsatisfactory and therefore, an optimization of the method of PDT is necessary. The endogenous photosensitizer aminolaevulinic acid with its high mucosa specificity without phototoxic side effects of the skin which can be administered orally was successfully used by our group for the treatment of patients with severe dysplasia of Barrett's esophagus and superficial squamous cell carcinomas. In patients with severe dysplasia/carcinoma in situ of Barrett's esophagus and early squamous cell carcinomas who pose high surgical risk, photodynamic therapy might be an effective alternative treatment modality in the future.
Animals↗