Showing papers in "Endoscopy in 2004"

Narrow-band imaging in the diagnosis of colorectal mucosal lesions: a pilot study.

Abstract: BACKGROUND AND STUDY AIMS A newly developed narrow-band imaging (NBI) technique, in which modified optical filters were used in the light source of a video endoscope system, was applied during colonoscopy in a clinical setting. This pilot study evaluated the clinical feasibility of the NBI system for evaluating colorectal lesions. PATIENTS AND METHODS A total of 43 colorectal lesions in 34 patients were included in the study. The quality of visualization of colorectal lesions and the accuracy of differentiation between neoplastic and non-neoplastic lesions using the NBI system were evaluated in comparison with results from conventional colonoscopy and with chromoendoscopy. RESULTS For pit pattern delineation, NBI was superior to conventional endoscopy (P < 0.001), but inferior to chromoendoscopy (P < 0.05). NBI achieved better visualization of the mucosal vascular network and of the hue of lesions than conventional endoscopy (P < 0.05). However there was no significant difference between NBI and chromoendoscopy in differentiating neoplastic from non-neoplastic lesions (both techniques had a sensitivity of 100 % and a specificity 75 %). This was better than the results of conventional colonoscopy (sensitivity 83 %, specificity 44 %; P < 0.05 for specificity). CONCLUSIONS These results suggest that in the examination of colonic lesions the NBI system provides imaging features additional to those of both conventional endoscopy and chromoendoscopy. For distinguishing neoplasms from non-neoplastic lesions, NBI was equivalent to chromoendoscopy.

Magnifying endoscopy combined with narrow band imaging system for early gastric cancer: correlation of vascular pattern with histopathology (including video).

Abstract: Background and study aims The narrow band imaging (NBI) system consists of a sequential electronic endoscope system and a source of light equipped with new narrow band filters, yielding very clear images of microvessels on mucosal surfaces. The aim of this prospective study was to measure the correlation between the magnified images obtained with the NBI system and the histological findings, especially with regard to the vascular pattern. In addition, three-dimensional images of microvessels were reconstructed using a laser scanning microscope. Patients and methods Between July 2001 and August 2003, 165 patients with depressed-type early gastric cancer lesions were enrolled in the study. The lesions were carefully observed with magnification using the NBI system. The images, the pathological characteristics of the lesions, and three-dimensionally reconstructed images of the microvascular networks in biopsied specimens were carefully analyzed. The microvascular patterns were classified into three groups: A, fine network; B, corkscrew; and C, unclassified pattern. The endoscopic images were compared with the histological findings. Results Of the three types of filter available for use with the NBI system, microvascular formation was best enhanced in B mode images produced using short wavelengths, which focus on the superficial mucosal layer. Among 109 cases of differentiated adenocarcinoma, the group A microvascular pattern was observed in 72 cases (66.1 %). Among 56 cases of undifferentiated adenocarcinoma, the group B pattern was observed in 48 cases (85.7 %; P = 0.0011) The microvascular structure observed using the NBI system corresponded with the superficial mucosal layer in the three-dimensional images obtained using laser scanning microscopy and the resected specimens. Conclusions Magnifying endoscopy performed in combination with the NBI system is not sufficient to replace conventional histology, but is capable of predicting the histological characteristics of gastric cancer lesions.

Self-expanding metal stents for gastroduodenal malignancies: systematic review of their clinical effectiveness.

Abstract: Background and study aims The current standard approach to the management of malignant gastric outlet obstruction mainly involves bypass surgery, which is associated with significant rates of mortality and morbidity. Recently, metal stents have emerged as a new therapeutic option. The aim of the present study was to review the currently published evidence on the effectiveness and safety of this form of endoscopic treatment. Materials and methods A systematic review of the published data was carried out by searching medline, embase, and abstracts from the major gastroenterological conferences from January 1992 to September 2003. A total of 136 relevant publications were identified (case series, single case reports, letters and editorials, or reviews). The systematic review included 32 case series from a total of 46 publications identified as reporting primary clinical data. Abstracts and single case reports were not taken into account. Analysis of these 32 case series included data on technical success (successful stent placement and deployment), clinical success (relief of symptoms such as nausea and vomiting, and/or improvement of food intake), and complications. Pooled results were calculated from the 32 studies (10 of which were prospective). Results Stent insertion was attempted in 606 patients with malignant symptomatic gastroduodenal obstruction; 94 % of the patients were unable to take food orally or were mainly ingesting liquids. Stent placement and deployment were successful in 589 of the patients (97 %). Clinical success was achieved in 526 patients in the group in which technical success was reported (89 %; 87 % of the entire group undergoing stenting). Disease-related factors accounted for the majority of clinical failures. Oral intake became possible in all of the patients in whom a successful procedure was carried out, with 87 % taking soft solids or a full diet, with final resolution of symptoms occurring after a mean of 4 days. There was no procedure-related mortality. Severe complications (bleeding and perforation) were observed in seven patients (1.2 %). Stent migration was reported in 31 patients (5 %). Stent obstruction occurred in 104 cases (18 %), mainly due to tumor infiltration. The mean survival period was 12.1 weeks. Conclusions Published evidence from case series suggests that gastroduodenal stenting offers good palliation and is a safe and effective treatment option in patients with a short remaining lifespan. However, patient selection for this intervention continues to be an issue requiring thorough consideration, and studies comparing the method with surgery are needed.

Comparison of various submucosal injection solutions for maintaining mucosal elevation during endoscopic mucosal resection

Abstract: Background and study aims One of the major complications of endoscopic mucosal resection (EMR) for gastrointestinal tumors is perforation, and the most effective way of preventing perforation is to elevate the lesion sufficiently by endoscopic injection of fluid into the submucosa. Materials and methods In order to compare the lesion-lifting properties of several different solutions, 1 ml of each of the following solutions was injected into the submucosa of the resected porcine stomach: normal saline, 3.75 % NaCl, 20 % dextrose water, 10 % glycerin with 0.9 % NaCl plus 5 % fructose, and two sodium hyaluronate (SH) solutions. Results Significantly higher initial elevation was produced by both SH solutions, and it remained higher than that achieved by the other solutions at all times. Hypertonic solutions, especially 10 % glycerin with 0.9 % NaCl plus 5 % fructose, tended to produce and maintain greater mucosal elevation than normal saline, but the difference was not significant. Conclusions SH solutions were the most suitable ones for producing and maintaining long-term mucosal elevation, while the superiority of hypertonic solutions over normal saline was not clearly demonstrated.

Chromoendoscopy using indigo carmine dye spraying with magnifying observation is the most reliable method for differential diagnosis between non-neoplastic and neoplastic colorectal lesions: a prospective study.

Abstract: Background and aims Differential diagnosis between non-neoplastic and neoplastic lesions is very important at colonoscopy, since removal or biopsy of non-neoplastic polyps wastes time and resources. We therefore conducted a prospective study to examine whether indigo carmine dye spraying with and without magnification is more reliable than the conventional method for differential diagnosis. Patients and methods 122 patients with 206 lesions of 10 mm or smaller were recruited into this study. All lesions detected on colonoscopy were first diagnosed using the conventional view, then at chromoendoscopy using 0.2 % indigo carmine, and finally at chromoendoscopy with magnification. The diagnosis at each step were recorded consecutively. All lesions were finally categorized as neoplastic or non-neoplastic according to pit pattern; non-neoplastic lesions were biopsied for histological evaluation, and all the neoplastic ones were removed endoscopically. The accuracy rate of each type of endoscopic diagnosis was evaluated, using histological findings as reference. Results Histologically, 46 lesions (22 %) were non-neoplastic and 160 (78 %) were neoplastic. The overall diagnostic accuracies by conventional view, chromoendoscopy, and chromoendoscopy with magnification were 84.0 % (173/206), 89.3 % (184/206) and 95.6 % (197/206), respectively. Conclusion Chromoendoscopy with magnification is the most reliable method for determining whether a colorectal lesion is non-neoplastic or neoplastic.

Attempted endoscopic en bloc resection of mucosal and submucosal tumors using insulated-tip knives: a pilot series.

Abstract: BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection (EMR) of early gastrointestinal cancers has been shown to be effective in treating mucosal malignancies, but en bloc resection (where the entire tumor is removed in one piece) is often not achieved using conventional cap EMR. Other techniques, developed in Japan, include the application of different types of knife such as the insulated-tip instrument. We report our preliminary experience of the use of this knife, in conjunction with other techniques, in attempting en bloc resection of early mucosal cancers and adenomas and in the removal of submucosal tumors (SMTs) of the upper gastrointestinal tract. PATIENTS AND METHODS: A total of 37 patients (26 men, 11 women, age range 53 - 86) were included in the study; 23 patients had 24 mucosal lesions amenable to EMR, and 14 patients had SMTs shown on endosonography to spare the muscularis propria. Lesions were located in the esophagus (n = 13), the stomach (n = 24), and the duodenum (n = 1); 40 % of the mucosal lesions were 20 mm or larger (mean size 18mm), whereas the mean size of the submucosal lesions was 23 mm. After submucosal saline injection, circumcision and dissection of the mucosal lesions was attempted with the aim of achieving en bloc resection. For SMTs, cap mucosectomy of the overlying mucosa was done first, and the tumors were then freed using saline injection, and finally resected using snare polypectomy. RESULTS: The strict aim of the study, i. e. complete tumor removal in a single piece, was achieved in only 25 % of the mucosal lesions (some failures were due to unrecognized submucosal infiltration) and 36 % of the SMTs. When a more liberal definition of success was assumed, this rate increased to 65 % for mucosal lesions (piecemeal, no tumor found at surgery or follow-up endoscopy with biopsy) and 79 % for SMTs (piecemeal). No severe complications necessitating surgery or leading to major morbidity occurred. However, clinically significant complications were found in six patients (minor perforation managed conservatively (n = 1), severe pain without perforation (n = 1), bleeding requiring reintervention (n = 3), and aspiration (n = 1)). CONCLUSIONS: Although we are convinced that methods of achieving en bloc resection of mucosal cancers and SMTs must be pursued, the insulated-tip knife in conjunction with conventional endoscopes still has limitations. Innovative endoscope design (double-channel scopes) as well as the development of new accessories will help to overcome the current limitations and further promote endoscopic tumor resection.

Comparison of EUS-guided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration.

Abstract: Background and study aims The accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) depends on immediate specimen review by a cytopathologist. Stromal tumors, lymphoma, and well-differentiated pancreatic cancer are difficult to diagnose on the basis of cytology alone. To overcome these limitations, a 19-gauge Trucut needle has been developed to obtain histological samples at EUS. This pilot study compares the specimen adequacy and diagnostic accuracy of EUS-guided Trucut needle biopsy (EUS-TNB) with EUS-FNA. Patients and methods A total of 18 patients underwent EUS-TNB and EUS-FNA. The specimen adequacy and diagnostic accuracy of the two techniques was compared. The technical performance and safety profile of the Trucut needle were also evaluated. Results The EUS-TNB specimen was adequate for evaluation in 15/18 patients compared with 18/18 with EUS-FNA (83 % vs. 100 %, not significant). The diagnostic accuracy of EUS-TNB was not significantly different from EUS-FNA (78 % vs. 89 %). Two complications were encountered: one patient developed mediastinitis and required surgery; another had immediate bleeding that was managed conservatively. One technical problem was encountered: the Trucut needle failed to deploy after two passes when a gastric stromal cell tumor was being biopsied. Conclusion The diagnostic accuracy of the new EUS-TNB is comparable to that of EUS-FNA. In our experience, the overall efficacy and safety profile of the Trucut needle appears modest.

Comparison of capsule endoscopy and magnetic resonance imaging for the detection of polyps of the small intestine in patients with familial adenomatous polyposis or with Peutz-Jeghers' syndrome.

Abstract: Background and study aims We have conducted a study to compare the diagnostic yields of magnetic resonance imaging (MRI) and capsule endoscopy for the detection of small-bowel polyps in patients with inherited polyposis syndromes Patients and methods MRI was performed in 20 patients, with either Peutz-Jeghers' syndrome (PJS; n = 4) or familial adenomatous polyposis (FAP; n = 16), and capsule endoscopy was done the next day The number, size, and location of polyps were analyzed Results Overall, 448 polyps ranging from about 1 mm to 30 mm in size were detected in eight patients by capsule endoscopy, whereas with MRI only 24 polyps all bigger than 5 mm could be seen in the four PJS patients Conclusions Polyps bigger than 15 mm were detected similarly with capsule endoscopy and MRI, whereas smaller polyps were seen much more often with capsule endoscopy Polyps smaller than 5 mm were exclusively seen with capsule endoscopy However, location of the detected polyps and determination of their exact sizes was more accurate by MRI

Clinical usefulness of the endoscopic video capsule as the initial intestinal investigation in patients with obscure digestive bleeding: validation of a diagnostic strategy based on the patient outcome after 12 months.

Abstract: Background and study aims In patients with obscure digestive bleeding, the bleeding source is frequently located in the small bowel. Capsule endoscopy (CE) is an effective method of investigating the whole small bowel in such patients. In the present study, a diagnostic approach was tested in patients with obscure digestive bleeding in which CE was included as the initial examination of the small bowel when the esophagogastroduodenoscopy (EGD) and colonoscopy findings were normal. Patients and methods Patients admitted between October 2000 and February 2002 for obscure digestive bleeding underwent CE as the initial intestinal investigation, and the further management was decided on the basis of the results. After 12 months, follow-up data were obtained from all patients and referring physicians. The positive predictive value was calculated as the percentage of patients in whom CE detected a relevant lesion, and the negative predictive value as the percentage of patients with normal CE in whom no intestinal lesion was detected during the follow-up period. Results Forty-four patients (21 men, 23 women, aged 63 +/- 17 y) were included in the study. Twenty-two had overt bleeding and 22 had occult bleeding. CE detected an intestinal lesion in 18 patients (41.9 %)-- nine with angiomas, five with ulcers, one with a tumor, two with portal hypertension, and one with ischemic ileitis. The findings were normal in 17 patients (39.5 %). CE detected upper gastrointestinal lesions missed at EGD in four patients and blood in the stomach in two patients or in the proximal colon in three, leading to new endoscopies. Intestinal lesions detected at CE were treated as follows: push enteroscopy with treatment in eight patients, surgery in four, and medical treatment in six. In eight patients who underwent push enteroscopy, the procedure did not reveal lesions missed by CE. After 1 year, 15 of the 18 patients treated for intestinal lesions had no further bleeding and no anemia; one died after surgery (for resection of an ischemic intestinal loop), one relapsed, and one was diagnosed with a different intestinal condition. In all patients with extraintestinal lesions or blood detected at CE, further endoscopies led to diagnosis and therapy, with a favorable outcome. In patients with normal CE, no intestinal lesion was detected, but an extraintestinal source of bleeding was diagnosed and treated in nine patients (in the upper gastrointestinal tract in five cases and in the colon in four). Three patients had anemia of hematological origin and four had inadequate iron intake. The positive predictive value of CE was 94.4 % in patients with intestinal lesions, and the negative predictive value was 100 % in patients with normal CE findings. Conclusions In patients with obscure digestive bleeding, CE positively predicted the intestinal diagnosis or normal status in 95.5 % of cases. A diagnostic approach to obscure digestive bleeding that includes CE after the initial endoscopic work-up thus appears to be a valid strategy for small-bowel examinations.

Comparison of duodenal stent placement with surgical gastrojejunostomy for palliation in patients with duodenal obstructions caused by pancreaticobiliary malignancies.

Abstract: BACKGROUND AND STUDY AIMS Palliative treatment for duodenal stenosis with an enteral stent is effective in enhancing the quality of life of patients with duodenal obstruction. There have been no thorough comparisons of duodenal stent placement with standard surgical gastrojejunostomy. The present study evaluated the outcome of duodenal stent placement and surgical gastrojejunostomy for palliation of duodenal stenosis caused by pancreaticobiliary malignancies. PATIENTS AND METHODS Medical records for patients who underwent palliative enteral stenting during the past 9 years were retrospectively reviewed, and the patients' clinical outcome was compared with that in patients who underwent open surgical gastrojejunostomy during the same period. Patients who underwent prophylactic gastrojejunostomy were excluded from the study. RESULTS Twenty patients (11 men, nine women; mean age 71.8 years) with pancreaticobiliary malignancy underwent palliative enteral stenting (stent group). Nineteen patients (12 men, seven women; mean age 68.7 years) with pancreaticobiliary malignancies underwent surgical gastrojejunostomy (bypass group). In the stent group, the diagnoses were 12 pancreatic cancers, six gallbladder cancers, one bile duct cancer, and one ampullary cancer. In the bypass group, the diagnoses were 14 pancreatic cancers and five gallbladder cancers. There were no significant differences between the two groups with regard to clinical background. Both procedures were successful. There were no differences between the two groups with regard to the technical or clinical success rates, patient survival, possibility of discharge, need for parenteral nutrition, or incidence of complications. However, the time from the procedure to resumption of food intake was shorter in the stent group than in the bypass group (1 day vs. 9 days; P < 0.0001). Improvement in the performance score after the procedure was observed more frequently in the stent group (65 % vs. 26.3 %; P < 0.05). In terms of the median hospital stay from the time of the procedure to the time of initial discharge home (12 patients vs. nine patients), there was no statistical difference (15 days vs. 30 days) due to the small size of the sample. There was no procedure-related mortality in either group. CONCLUSIONS Palliative stent placement was more beneficial than surgical gastrojejunostomy in enhancing the quality of life of patients with duodenal obstruction due to pancreaticobiliary malignancies.

Use of self-expandable plastic stents for the treatment of esophageal perforations and symptomatic anastomotic leaks.

Abstract: BACKGROUND AND STUDY AIMS Extensive anastomotic leaks after esophageal resection and esophageal perforations are a therapeutic challenge. The aim of the present study was to assess the potential of the self-expandable Polyflex plastic stent for the treatment of these conditions. PATIENTS AND METHODS Between January 2002 and March 2003, nine patients were treated with a self-expandable Polyflex plastic stent for sealing of thoracic esophagoenteric anastomotic leaks following surgical resection (n = 5) or esophageal perforation (n = 4). RESULTS In all patients the stents were inserted successfully without technical problems. In all but two patients complete sealing of the leak was achieved as demonstrated by radiography with water-soluble contrast media. The stent migration rate was 30 % and repositioning of the migrated stents was possible in all cases. Complete mucosal healing of the esophageal leaks and stent extraction was achieved in six patients. The stents were in situ for an average period of 135 +/- 78 days. Two critically ill patients with anastomotic leaks died in spite of stent insertion due to sepsis and one patient with esophageal perforation died due to the underlying malignant disease. CONCLUSIONS Our preliminary experience with the self-expanding and removable Polyflex plastic stent for the sealing of anastomotic leaks and esophageal perforations suggests that this stent is a feasible treatment option, in particular, for more extensive esophageal defects, patients with co-morbid conditions, and critically ill patients.

Detachable snare versus epinephrine injection in the prevention of postpolypectomy bleeding: a randomized and controlled study.

Abstract: Background and study aims Several endoscopic techniques have been developed to prevent bleeding after the removal of large pedunculated polyps. Patients and methods From January 1995 to December 2002, 488 consecutive patients with pedunculated colorectal polyps, the heads of which were larger than 10 mm in diameter, were randomly assigned to three groups. In group A (163 patients), detachable snares were placed at the base of the stalk and standard snares were then used for polypectomy. In group B (161 patients), the polyp stalk was injected with a 0.01 % epinephrine solution before conventional snare polypectomy. Group C (a control group including 164 patients) underwent conventional snare polypectomy without preventive measures. Early ( 24 h - 30 days) bleeding complications were assessed. Each group was divided into two subgroups relative to the polyp size (polyps 1.0 - 1.9 cm and polyps > or = 2 cm). Results Overall bleeding complications occurred after 4.3 % of the polypectomies. Bleeding was successfully controlled in all patients, and no blood transfusions were required. There were three cases of bleeding in group A (1.8 %), five in group B (3.1 %), and 13 in group C (7.9 %). Early bleeding was more frequent than late bleeding (15 vs. six patients). In polyps > or = 2 cm (207 patients), postpolypectomy bleeding occurred in 14 patients (6.7 %): two (2.7 %) in the detachable snare group, two (2.9 %) in the epinephrine injection group, and 10 (15.1 %) in the control group. Conclusions These results show that polypectomy of large pedunculated polyps is associated with a higher incidence of bleeding. Particularly in polyps larger than 2 cm, preventive measures can significantly reduce bleeding complications after polypectomy. This can be achieved with similar efficacy either by placing Endoloops or by injecting epinephrine.

Missed Diagnoses in Patients With Upper Gastrointestinal Cancers

Abstract: Background and study aims A few studies have been published on cancers missed at previous endoscopy, but detailed analyses of the causes for failure were lacking. The aims of our study were to determine the incidence of and causes for failure to detect oesophageal and gastric cancers after referral of patients to a surgical endoscopy unit. Patients and methods Out of a consecutive series of 305 patients diagnosed with oesophageal and gastric cancers, we retrospectively identified patients who had undergone an endoscopy within 3 years before the diagnosis. The timing of previous endoscopies, indications for endoscopy, endoscopic findings and the number of biopsy specimens taken were recorded. Missed diagnoses were categorized as either definitely or possibly missed and the reasons for failure were documented. Results Of the 305 patients, 30 (9.8 %) had undergone a minimum of one endoscopy within the previous 3 years, 20 (67 %) of these within the previous 1 year. Sinister symptoms were present at the time of previous endoscopies in 75 % of patients with oesophageal cancer (n = 16) and in 57.2 % of patients with gastric cancer (n = 14). In 56 % of the patients with oesophageal cancers the initial diagnosis was oesophagitis or benign stricture; in 71.4 % of the patients with gastric cancers the initial diagnosis was gastritis, ulcer or "suspicious lesion". Among those patients with a definitely missed diagnosis (7.2 %), endoscopist errors accounted for the majority of failures (73 %) and the remainder were due to pathologist errors (27 %). Conclusions Missed cancers were a frequent finding in patients with oesophageal and gastric cancer who had undergone previous endoscopy, and errors by the endoscopists accounted for the majority of missed lesions. This study emphasizes the importance of identifying signs of early cancers and of having a low threshold for performing multiple biopsies of any suspicious-looking lesion.

Circumferential endoscopic mucosal resection in Barrett's esophagus with high-grade intraepithelial neoplasia or mucosal cancer. Preliminary results in 21 patients.

Abstract: Background and study aims Treatment by endoscopic mucosal resection (EMR) has been established for early lesions in Barrett's esophagus. However, the remaining Barrett's esophagus epithelium remains at risk of developing further lesions. The aim of this study was to evaluate the efficacy of circumferential endoscopic mucosectomy (circumferential EMR)s in removing not only the index lesion (high-grade intraepithelial neoplasia (HGIN) or mucosal cancer), but also the remaining Barrett's esophagus epithelium. Patients and methods A total of 21 patients were included in the study (11 men, 10 women), who had Barrett's esophagus and either HGIN (n = 12) or mucosal cancer (n = 9). Of the patients, 17/21 were at high surgical risk and five had refused surgery. On the basis of preprocedure endosonography their lesions were classified as T1N0 (n = 19) or T0N0 (n = 2). The lesions and the Barrett's esophagus epithelium were removed by polypectomy after submucosal injection of 10-15 ml of saline; a double-channel endoscope was used in 15/21 cases. Circumferential EMR was performed in two sessions, the lesion and the surrounding half of the circumferential Barrett's esophagus mucosa being removed in the first session. In order to prevent the formation of esophageal stenosis, the second half of the Barrett's esophagus mucosa was resected 1 month later. Results Complications occurred in 4/21 patients (19 %), consisting of bleeding which was successfully managed by endoscopic hemostasis in all cases. No strictures were observed during follow-up (mean duration 18 months) and endoscopic resection was considered complete in 18/21 patients (86 %). For three patients, histological examination showed incomplete removal of tumor: one of these underwent surgery; two received chemoradiotherapy, and showed no evidence of residual tumor at 18 months' and 24 months' follow-up, respectively. Two patients in whom resection was initially classified as complete later presented with local recurrence and were treated again by EMR. Barrett's esophagus mucosa was completely replaced by squamous cell epithelium in 15/20 patients (75 %). Conclusions Circumferential EMR is a noninvasive treatment of Barrett's esophagus with HGIN or mucosal cancer, with a low complication rate and good short-term clinical efficacy. Further studies should focus on long-term results and on technical improvements.

Magnifying Chromoendoscopy of the Esophagus: In-Vivo Pathological Diagnosis Using an Endocytoscopy System

Abstract: Background and study aims The aim of the present study was to observe the endoscopic characteristics of cells on the surface layer of superficial esophageal carcinomas in vivo using an endocytoscopy system and to compare the findings with those in normal squamous epithelium. Patients and methods Superficial esophageal cancers in 12 patients were examined with methylene blue staining using an endocytoscopy system. Results The endocytoscopy system and methylene blue staining made it possible to observe cells on the surface of the squamous epithelium in normal esophageal mucosa. Normal cells were arranged homogeneously, and the nucleus cytoplasm ratio was uniform and low. In esophageal cancers, the density of cells was found to be much greater than that in normal squamous epithelium. The cell distribution was also irregular and the cells were extremely heterogeneous, with the nuclei having different staining, size, and shape characteristics. The nucleus cytoplasm ratio was also very irregular. Conclusions Examining esophageal tissue using the endocytoscopy system described here makes it possible to observe detailed histological alterations in esophageal lesions in vivo.

The No Endosonographic Detection of Tumor (NEST) Study: a case series of pancreatic cancers missed on endoscopic ultrasonography.

Abstract: Background and Study Aims: The purpose of this study was to identify possible associated factors that may have contributed to failure to detect a pancreatic neoplasm during endoscopic ultrasound (EUS) examinations by experienced endosonographers. Patients and Methods: A multicenter retrospective study was organized, and 20 cases of pancreatic neoplasms missed by nine experienced endosonographers were identified. Careful analysis of each case was carried out to identify the factors that might have led to the missed diagnosis on EUS. Results: Twelve patients with a missed pancreatic neoplasm had EUS features of chronic pancreatitis. Other factors that might have increased the likelihood of a false-negative EUS examination included a diffusely infiltrating carcinoma (n = 3), a prominent ventral/dorsal split (n = 2), and a recent episode (within the previous 4 weeks) of acute pancreatitis (n = 1). Five patients with a negative initial EUS underwent a follow-up EUS after 2-3 months, with a pancreatic mass being found in all cases. Three patients had a diffusely infiltrating pancreatic adenocarcinoma. Conclusions: EUS is not a foolproof method of detecting a pancreatic neoplasm. Possible associated factors that may increase the likelihood of a false-negative EUS examination include chronic pancreatitis, a diffusely infiltrating carcinoma, a prominent ventral/dorsal split and a recent episode (<4 weeks) of acute pancreatitis. If there is a high clinical suspicion of pancreatic neoplasm, if EUS and other imaging methods are negative, and if the patient does not undergo surgery, this study suggests that a repeat EUS after 2-3 months may be useful for detecting an occult pancreatic neoplasm. © Georg Thieme Verlag KG Stuttgart.

Reasons for Failure to Diagnose Colorectal Carcinoma at Colonoscopy

Abstract: Background and Study Aims: Colonoscopy can produce false- these 66 patients, and management was being provided. Seven-negative results, and the reasons for this remain obscure. The teen cancers (5.9%) were missed at colonoscopy, and the patients aim of this study was to examine why cancers are missed at co- had had an incomplete colonoscopy in nine of these cases. In sevlonoscopy. Patients and Methods: All colonoscopies carried out en of the 17, an alternative benign cause was recorded. In four paat Christchurch Hospital, New Zealand, over a 43-month period tients, a lesion was seen and thought to be benign, although sub(1 October 1997 - 30 April 2001) were retrospectively analyzed sequently proven not to be. In another four cases, the cancer was (the data having been prospectively collected). All cases of colo- not diagnosed despite adequate bowel preparation and what was rectal carcinoma during the period 1 October1997- 30 July 2001 thought by the colonoscopist to be an adequate colonoscopy. (3 months longer, to capture delayed diagnoses) were also iden- Conclusions: Colonoscopy missed 17 of 286 cancers (5.9%). The tified. The two databases were then compared, and all cases in reasons why cancers were missed relate to incomplete colonoswhich a colonoscopy had been performed more than 6 weeks be- copy, poor bowel preparation, misinterpretation of what was fore a colorectal carcinoma specimen being received by the pa- seen, failure to carry out adequate biopsy (and follow-up) of lethology department were identified and analyzed. Results: A to- sions seen, and systems failures related to follow-up investigatal of 5055 colonoscopies were undertaken in 4598 patients. tions in patients who had an incomplete colonoscopy. The fact Over this period, 630 colorectal carcinomas were identified in that colonoscopy and barium enema investigations may fail to the pathology database; 286 of the patients affected were in the diagnose cancers has important medicolegal implications. The colonoscopy and pathology database. Sixty-six patients had had recognition that colonoscopy may miss a cancer should encoura colonoscopy performed more than 6 weeks before the diagno- age doctors to reinvestigate patients when there is a lack of corsis of colorectal carcinoma. Carcinoma was identified in 48 of relation between the clinical and investigative findings.

Histological analysis of endoscopic resection specimens from 326 patients with Barrett's esophagus and early neoplasia.

Abstract: Background and study aims Endoscopic resection has been recommended as a local curative approach for Barrett's neoplasia, but large series are still rare. In the present study we analyzed the histological characteristics of endoscopic resection specimens of Barrett's neoplasia. Patients and methods 742 endoscopic resection specimens obtained from 326 patients were assessed. The following histological characteristics were evaluated: type of neoplasia, grade of differentiation, depth of infiltration, invasion into lymphatic and blood vessels, and resection status (tumor-free margins were regarded as indicating R0 status). Results 31 patients had no neoplasia and were excluded from the analysis. Among the remaining 295 patients (711 resection specimens), histological findings were: low-grade intraepithelial neoplasia, 1.0 %; high-grade intraepithelial neoplasia, 2.7 %; and mucosal carcinoma 80.3 %. Carcinomas infiltrating the submucosal layer were rare (sm1 7.5 %; sm2 3.7 %; sm3 4.8 %), as were those invading lymph vessels (3.5 %), and there were none with venous invasion. Most of the carcinomas were well-differentiated (72.2 %), and many of these (92.7 %) were limited to the mucosa, in contrast to moderately and poorly differentiated carcinomas (73.7 % and 22.7 %, respectively). R0 status was achieved in 74.5 % of patients; in 47.8 % this was after repeated endoscopic resection. In 26.8 % of patients, R0 resection was achieved at the first attempt. Conclusions Our study demonstrates that early Barrett's neoplasms removed by endoscopic resection are mostly limited to the mucosa, are well to moderately differentiated, and very rarely show invasion of the lymph or blood vessels. Although these lesions seem to be low risk with regard to metastatic spread and therefore treatable endoscopically, improved endoscopic resection methods for achieving one-piece (en bloc) R0 resection should be developed.

The value of capsule endoscopy in pediatric patients with a suspicion of Crohn's disease.

Abstract: Background and Study Aims: The aim of this study was to assess the safety and usefulness of capsule endoscopy (CE) in pediatric patients with a suspicion of Crohn's disease. Patients and Methods: CE was used in 12 patients (four girls, eight boys; age 12 - 16; weight range 43-87 kg). The indication was a clinical suspicion of Crohn's disease not confirmed with traditional methods. Gastroscopy, colonoscopy, and small-bowel follow-through examinations were carried out in all of the patients, without any diagnostic findings. Ileoscopy was possible in 50% of the patients, and the ileal mucosa and biopsies were normal in all cases. Results: The capsule was easily swallowed by all of the patients. They all excreted the capsule normally, and no complications were observed in any case. CE identified lesions suggestive of Crohn's disease in seven of the 12 (58.3%), and the majority of the lesions were in the ileum. Conclusions: CE is safe in pediatric patients over 12 years of age. The procedure appears to be a very useful diagnostic tool in children with Crohn's disease.

Endoscopic treatment outcomes in watermelon stomach patients with and without portal hypertension.

Abstract: Background and study aims Watermelon stomach is a source of recurrent gastrointestinal hemorrhage and anemia. The aims of this study were to describe the endoscopic appearance and treatment outcomes in watermelon stomach patients with and without portal hypertension. Patients and methods All patients with watermelon stomach enrolled in a hemostasis research group's prospective studies from 1991 to 1999 were identified. Investigators collected data using standardized forms. Comparisons were made using the chi-squared test, Wilcoxon rank-sum test, and Wilcoxon signed-rank test. Results Twenty-six of 744 (4 %) consecutively enrolled patients with nonvariceal upper gastrointestinal hemorrhage had watermelon stomach as the cause. Eight of these 26 patients (31 %) also had portal hypertension. These patients had diffuse antral angiomas, as opposed to the classic linear arrays seen in those without portal hypertension. The demographic data and clinical presentations of the two groups were otherwise similar. Palliative endoscopic treatment was associated with a significant rise in hematocrit and a decrease in the need for blood transfusion or hospitalization in watermelon stomach patients with and without portal hypertension. Conclusions Watermelon stomach patients with and without portal hypertension had similar clinical presentations. The endoscopic findings differed in that those with portal hypertension had more diffuse gastric angiomas. Bleeding was effectively palliated by endoscopic treatment, regardless of the presence of portal hypertension.

Acute necrotizing esophagitis: a large retrospective case series.

Abstract: Background and study aims Acute necrotizing esophagitis is a rarely described entity. Its incidence has not yet been established, and its multifactorial etiology remains unknown. The aim of the present study was to establish the incidence, clinical presentation, endoscopic course, accompanying factors, and pathogenesis of the condition. Patients and methods A retrospective analysis of clinical, laboratory, endoscopic and histological data and the clinical course in 29 patients with acute necrotizing esophagitis was carried out over a 5-year period. Results Acute necrotizing esophagitis was observed in 29 of 10 295 upper gastrointestinal endoscopies (0.28 %) carried out during the 5-year period. The average age of the patients was 75.24 years (range 40 - 91), and they were predominantly male. Eighty-three percent of the patients had comorbid conditions. In all cases, acute necrotizing esophagitis became evident with upper gastrointestinal bleeding, without hemodynamic stabilization in the majority of cases (75.9 %). The lesions predominantly affected the lower two-thirds of the esophagus (59 %), and there were coexisting abnormal endoscopic findings in 83 % of cases. Empirical supportive therapy, including oral nutritional rest, omeprazole, sucralfate (15 cases) and broad-spectrum antibiotics (7 cases) was provided. The condition resolved in all patients. Ten patients in the group died of other causes (coexisting illnesses). Conclusions Acute necrotizing esophagitis was more commonly recognized than has previously been reported. It is a serious clinical entity that should be considered in the differential diagnosis of upper gastrointestinal bleeding, particularly in elderly patients. The prognosis depends more on the patient's advanced age and on comorbid illnesses than on the course of the esophageal lesions, which resolved in all patients in this series.

Long-term follow-up study of gastric adenoma/dysplasia.

Abstract: Background and Study Aims: The natural course of gastric adenoma/dysplasia, regarded as a precancerous lesion, is still uncertain. Patients and Methods: From 1976 to 2000, 48 lesions in 43 pall tients (37 men, six women; mean age 59 years) were diagnosed as having gastric adenoma/dysplasia based on their first biopsies. These lesions were followed for a median of 4.7 years (mean 6 years, range 3-18 years) to evaluate the risk of progression to invasive carcinoma. Retrospectively, histological diagnoses of the biopsy and resected specimens were reclassified according to the Vienna classification of gastrointestinal epithelial neoplasia, and macroscopic changes were evaluated. Results: The diagnosis at first biopsy of the 48 lesions was low grade adenoma/dysplasia (LGD; category 3) in 38 cases and high-grade adenoma/dysplasia (HGD; category 4) in 10 cases. Ninety-seven percent of the LGD (category 3) lesions (37 of 38) showed no histological changes during the follow-up period; the remaining lesion progressed to noninvasive carcinoma (category 4). Macroscopically, 84% (32 of38) ofthe LGD lesions (category 3) showed no remarkable changes in size, while 11 % (four of 38) shrank and 5% (two of 38) grew larger. Nine of the 10 HGD lesions (category 4) remained histologically unchanged, while the other progressed to intramucosal carcinoma (category 5). Macroscopically, four of the 10 HGD lesions (category 4) (40%) showed no remarkable changes in size, while the remaining six (60%) grew larger. Conclusions: LGD lesions (category 3) have a quite low risk of progressing to HGD or noninvasive carcinoma (category 4), and were never observed to progress to invasive carcinoma (category 5). HGD lesions (category 4) occasionally progressed to intramucosal carcinoma (category 5), with no instance of invasion into the submucosa or beyond.

Causes and treatment of recurrent dysphagia after self-expanding metal stent placement for palliation of esophageal carcinoma.

Abstract: BACKGROUND AND STUDY AIMS: Recurrent dysphagia frequently complicates the palliative treatment of esophageal cancer with self-expanding metal stents. Strategies for repeat interventions and subsequent outcomes have not been adequately reported to date. PATIENTS AND METHODS: A total of 216 patients underwent placement of a self-expanding metal stent (Ultraflex, n = 75; Flamingo Wallstent, n = 71; Z-stent, n = 70) for malignant dysphagia, and were followed up prospectively. The causes of stent-related recurrent dysphagia, the intervals after first stent placement, and the procedures used for repeat intervention and their outcomes were evaluated. RESULTS: Seventy-four episodes of stent-related recurrent dysphagia occurred in 63 patients (29 %), mainly due to tumor overgrowth (n = 30; median 129 days), stent migration (n = 26; median 92 days) and food bolus obstruction (n = 16; median 80 days). Stent migration occurred more frequently ( P = 0.05), whereas tumor overgrowth occurred less frequently ( P = 0.05) with Ultraflex stents in comparison with Flamingo Wallstents and Z-stents. Tumor overgrowth was treated in 25 patients mainly by a second stent (n = 19) and was effective in 23 of the 25 patients (92 %). Five patients received no further treatment. Stent migration was treated by placing a second stent (n = 14), repositioning the migrated stent (n = 7), other treatments (n = 3), or no further treatment (n = 2), and treatment was effective in 20 of 24 (83 %) patients. Food bolus obstruction was treated by endoscopic stent clearance in all patients. Repeat intervention for stent-related recurrent dysphagia improved the dysphagia score from a median of 3 to 1 ( P < 0.001). The median survival period after repeat treatment was 68 days. CONCLUSIONS: Recurrent dysphagia occurs in almost one-third of patients after stent placement. Repeat interventions for stent-related recurrent dysphagia are effective in over 90 % of patients. New innovations in stent design are needed to reduce the risk of stent-related recurrent dysphagia.

Different mixtures of sodium hyaluronate and their ability to create submucosal fluid cushions for endoscopic mucosal resection.

Abstract: Background and study aims Sodium hyaluronate (SH) is a promising submucosal injection solution during endoscopic mucosal resection, but its high cost is an obstacle to more widespread use. The aim of this study was to identify an appropriate low-cost SH solution by varying the molecular weight of SH and mixing various solutions with it. Materials and methods The viscoelasticity of various SH solutions was first measured. The concentrations of two 1 % SH preparations with different molecular weights (800 kDa and 1900 kDa) were adjusted to 0.5 %, 0.25 %, and 0.125 %, using 0.9 %/3.75 % normal saline (NS), 5 %/20 % dextrose water (DW), and a glycerin solution (Glyceol): 10 % glycerin with 0.9 % normal saline plus 5 % fructose. The ability of these SH solutions to create submucosal fluid cushions (SFCs) was then investigated in the stomachs of two live minipigs. Results The 0.25 % 1900 kDa SH/NS solution and the 0.125 % 1900 kDa SH/20 % DW solution created a similar viscoelasticity to that of the 0.5 % 800 kDa SH/NS solution. The ability of these solutions to create SFCs was also similar. In addition, the 0.125 % 1900 kDa SH/Glyceol solution created similar SFCs, with a synergistic effect of increased viscoelasticity and the hypertonic nature of glycerin. Conclusions A mixture of higher molecular weight sodium hyaluronate with a sugar solution (particularly 20 % dextrose), with or without glycerin, should be regarded as a cost-effective option for creating SFCs instead of the conventional SH solution made with the same amount of a 1 % 800 kDa SH preparation and normal saline.

A prospective randomized trial comparing a virtual reality simulator to bedside teaching for training in sigmoidoscopy

Abstract: BACKGROUND AND STUDY AIMS Clinical investigation using endoscopy simulators is now possible due to recent advances in virtual reality technology. A prospective randomized trial was conducted to compare the exclusive use of a virtual reality endoscopy simulator with bedside teaching for training in sigmoidoscopy. MATERIALS AND METHODS Internal medicine residents were randomly assigned to training exclusively using a virtual reality simulator (group 1) or via bedside teaching (group 2). Residents were then observed performing five sigmoidoscopic procedures in asymptomatic patients referred for colorectal cancer screening. Endoscopic examinations were evaluated for procedure duration, completion, ability to perform retroflexion, and level of patient comfort/discomfort. Each examination was scored from 1 (inability to insert the endoscope beyond the rectum) to 5 (able to complete the entire examination independently in less than 20 min). RESULTS Sixty-six sigmoidoscopic examinations were completed by nine residents in group 1 (simulator-trained group) and seven residents in group 2 (traditional teaching group). Participants in group 1 had more difficulty with initial endoscope insertion and negotiation of the rectosigmoid junction (mean score +/- SEM 2.9 +/- 0.2) than those in group 2 (3.8 +/- 0.2) ( P < 0.001). The splenic flexure was reached independently in 10 of 34 examinations (29 %) in group 1, compared with 23 of 32 examinations (72 %) in group 2 ( P = 0.001). Retroflexion was successfully performed by 19 of 34 (56 %) in group 1 compared to 27 of 32 (84 %) in group 2 ( P = 0.02). The average procedure time, patient satisfaction, and discomfort associated with the procedure did not differ statistically between the two groups. CONCLUSIONS The use of a state-of-the-art virtual reality-based endoscopy simulator is inferior to traditional bedside teaching techniques when used exclusively for training medical residents to perform sigmoidoscopy.

Inter- and intra-observer variability of magnification chromoendoscopy for detecting specialized intestinal metaplasia at the gastroesophageal junction.

Abstract: BACKGROUND AND STUDY AIMS Magnification endoscopy after contrast enhancement with acetic acid or staining with methylene blue has been reported to be highly accurate in predicting specialized intestinal metaplasia (SIM) in Barrett's esophagus. So far, however, no data have been published on the interobserver and intra-observer variability of these new methods. PATIENTS AND METHODS Fifty-one patients with reflux symptoms were prospectively evaluated. Endoscopy was carried out with a magnification endoscope, and video sequences were recorded in standard and zoom modes (at the 12-o'clock, 3-o'clock, 6-o'clock, and 9-o'clock positions) before and after instillation of 1.5 % acetic acid (n = 26) or staining with 0.5 % methylene blue (n = 25). Biopsies were obtained from the same locations for histopathological examination. The 102 video sequences were shown to four experienced endoscopists in a mixed and blinded fashion. The evaluation criteria used followed the published criteria; classification was carried out according to the pit-pattern structure, methylene blue positivity, and the presence of villous structures. Finally, a general statement on suspected SIM in relation to Barrett's esophagus was requested. RESULTS With regard to the criteria selected for evaluation, there was a high level of interobserver variability among the four examiners (all kappa < 0.4). SIM was histologically detectable in 60.8 % of the patients. The accuracy of all of the examiners for predicting SIM by magnification endoscopy was around 50 %, with no differences observed before and after instillation of acetic acid or methylene blue staining. CONCLUSIONS The suggested criteria for identifying SIM using magnification endoscopy are associated with a high level of interobserver variability. When evaluated in a blinded manner, staining techniques do not significantly improve the yield for detecting SIM at the esophagogastric junction.

Endosonography versus helical computed tomography for locoregional staging of gastric cancer.

Abstract: BACKGROUND AND STUDY AIMS Endosonography (EUS) has been shown to be more accurate than incremental computed tomography (CT) in the local (T) and regional (N) staging of gastric carcinoma; however, EUS has never been compared with helical CT (HCT). The fifth edition of the TNM classification changed the guidelines for N-staging of gastric carcinoma. The accuracy of imaging methods in this new system remains unknown. PATIENTS AND METHODS Staging accuracy of EUS and HCT were compared prospectively with pathological or intraoperative findings in 88 gastric carcinoma patients. Staging was done according to the fourth and fifth editions of the TNM classification. EUS was done with a radial echo endoscope, and HCT with a scanner with two rows of detectors (two-phase contrast-enhanced scanning of a water-filled stomach). RESULTS The T-staging accuracy of EUS (63 %, CI 52 - 73 %) was superior to the accuracy of HCT (44 %, CI 34 - 55 %; P = 0.021). N-staging accuracy of both methods was similar when the fourth edition of the TNM classification was used (EUS 47 %, CI 34 - 60 %; HCT 52 %, CI 38 - 65 %). However, HCT was more accurate than EUS when the fifth edition of the classification was applied (EUS 30 %, CI 18 - 43 %, HCT 47 %, CI 34 - 60 %; P = 0.044). The accuracy of detection of lymph node metastases was similar for both methods (EUS 67 %, CI 54 - 78 %; HCT 77 %, CI 64 - 86 %). CONCLUSIONS EUS is more accurate than HCT in the T-staging of gastric carcinoma. Both methods are comparable for N-staging, when this is done according to the older, fourth edition of the TNM classification. If the fifth edition is used, EUS is less accurate than HCT.

Yield of endoscopic ultrasound-guided fine-needle aspiration of bile duct lesions

Abstract: Background and study aims It is still difficult to differentiate reliably between benign and malignant biliary tract lesions. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has added to the diagnostic power of EUS for other gastrointestinal tumors. A retrospective analysis of experience with FNA sampling of bile duct lesions was therefore carried out. Patients and methods All EUS-FNA procedures for bile duct masses or strictures were analyzed at our tertiary referral center from May 2000 through October 2002. Data for EUS findings, the results of EUS-FNA, and tissue sampling at surgery were included. EUS-FNA procedures were carried out using a 22-gauge needle. An experienced cytopathologist was present during FNA in all but three cases. Clinical follow-up details were recorded when available for patients in whom a suitable diagnostic gold standard was not available for comparison. Results A total of 35 patients underwent EUS-FNA of bile duct lesions during the study period. There were no complications. Data for EUS-FNA of bile duct masses or strictures and tissue obtained at surgery were available for 23 patients. If positive cytology at surgical pathology is taken as the gold standard, EUS-FNA has a diagnostic yield for cancer of 100 % (if atypia/inconclusive findings in the FNA sample are regarded as benign). Eleven patients had a definite malignancy on surgical pathology. Of these 11 patients, five had a finding of malignancy on EUS-FNA, giving a sensitivity of 45 % (if FNA cytology reported as atypia/inconclusive is regarded as benign). Twelve patients had findings of no malignancy from tissue obtained at surgery. Of these 12 patients, nine had benign pathology and three had atypia/inconclusive findings in the EUS-FNA sample (specificity of 100 % if atypia/inconclusive findings are considered benign). A further 12 patients did not have surgical specimens for comparison with EUS-FNA results. Four patients had definite findings of malignancy on EUS-FNA alone, and one patient had FNA findings suspicious for malignancy. Seven patients had negative or equivocal EUS-FNA results. These 12 patients are described but excluded from further analysis, as a gold standard was not available for comparison. However, clinical follow-up data were available for eight of these 12 patients, and in each case the follow-up findings were compatible with previous benign or malignant EUS-FNA findings. Conclusions The practice of EUS-FNA has improved the diagnostic yield of EUS. These results suggest that it is a safe and useful procedure for investigating biliary masses or strictures that have hitherto caused considerable diagnostic confusion, especially in patients with negative brush cytology findings. The possibility of false-negative findings remains, but core biopsy needles may improve the situation. The results of further studies are awaited.

The role of video capsule endoscopy in the diagnosis of digestive diseases: a review of current possibilities.

Abstract: Video capsule endoscopy represents a significant advance in the investigation of intestinal diseases. The performance of the procedure and indications are reviewed here in order to establish guidelines for its use, in accordance with current knowledge from the published literature. Capsule endoscopy is performed in patients who have fasted for 12 h, but who are allowed to drink 2 h after and to eat 4 h after ingesting the capsule. Software features highlighting suspected blood and allowing simultaneous viewing of two images reduce the time required to review the findings, as well as improving the diagnostic yield. Pacemakers and other electrical medical devices are no longer a contraindication to the procedure. Indications that have been validated include obscure digestive bleeding, intestinal lesions related to nonsteroidal anti-inflammatory drugs, and familial polyposis. Capsule endoscopy frequently detects intestinal lesions in patients with Crohn's disease and could become the first-choice examination in patients with suspected Crohn's disease after conventional endoscopic investigations. Other indications currently under evaluation include celiac disease, pediatric indications, and examination of other parts of the gastrointestinal tract.