Gastrointestinal endoscopy has completely entered the age of videoscope, as new types of videoscope are developed and improved one after another, providing new functions that prior endoscopes do not have such as various types of image analyses, image processing, data communication, data filing and so on. Obviously, videoscope could not have been brought into practical use without development of broadcasting television technology. The author have briefly explained the history of development of broadcasting television at the beginning. Application of television to endoscopy started with an attempt to project an endoscopic image on a TV monitor by attaching the TV camera tubes on the eyepiece of a f iberscope . It was not until solid-state image sensing device (charge coupled device, CCD) was developed and miniaturized that it became possible to insert a TV camera directly into stomach . The first videoscope was developed and reported in the United States in 1983, and several Japanese manufacturers set out development of videoscope. Today, there are a number of different videoscopes sold in the market. Basing on the explanation of the basic principle and theory of videoscope, development of image processing and analysis functions are illustrated that are gathering attention above all. Moreover, clinical application of infrared ray videoscope and the theory and significance of Narrow Band Imaging (NBI) and AIF (auto-fluorescence Imaging) are also stated as the focus of discussion these days. In relation to these topics, fear for inappropriate stretch of interpretation of the term "special light" is also pointed out with a proposal of a new classification by purposes of endoscopic observation (Niwa, Tajiri). IDTV, EDTV (clear hi-vision) and hi-vision are also introduced as well as liquid crystal display and rear-projection television that can replace CRT display.

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Vascular ectasia of the colon and small intestine is recognized as one of the disorder to cause gastrointestinal hemorrhage. However, it is confused that a definition of the term of vascular disorder is not decided. In endoscopy society nomenclature, acquired circumscribed vasodilatation was defined as vascular ectasia or angiectasia, and angiodysplasia or vascular malformation was defined as congenital disorders. Telangiectasia was also defined as genetic disease. Diagnosis of colonic vascular ectasia was as follows findings : strong focal red mucosa, vascular spider like vessels, meander or enlarged vessels. Small intestinal vascular ectasia was detected as active bleeding spot or erosion by capsule endoscope or balloon enteroscopy. In cases of asymptomatic, it was not necessary to active treatment. In cases of bleeding, clipping and coagulated methods such as high frequency current, heater probe and argon plasma coagulation. Argon plasma coagulation method was useful to expect regression of the lesion. In addition, apoplexy source was not clear, and angiography was useful when endoscopic examination was difficult or impossible.

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[Purpose]Recently, small caliber upper gastrointestinal endoscope have been developed for transnasal insertion. However, tolerability and incidence of adverse effect of this procedure had not been fully investigated. The aims of this study were to investigate the effect of small caliber endoscope on cardiopulmonary function and to evaluate which route was more acceptable, transnasal or transoral. [Methods](1) A total of 195 patients who received esophagogastroduodenoscopy (EGD) was enrolled in this study. All patients were randomly assigned to one of three groups of EGD procedure : (i) transnasal EGD using a small caliber endoscope ; (ii) transoral EGD using the same small caliber endoscope ; (iii) transoral EGD using a conventional endoscope. The number of patients in each group was 65. Blood pressure, pulse rate, arterial oxygen saturation and gagging were monitored. (2) The next study involved 37 healthy volunteers who underwent EGD, both transnasal and transoral with small caliber endoscope . All volunteers were randomly assigned to two groups : one was firstly examinened by transnasal and the other was firstly examined by transoral. The cross-over study was done to evaluate the feasibility of two procedures between them. [Results]In the transnasal EGD group, the changes of blood pressure, pulse rate and the number of gagging episodes were significantly lower than other groups . The cross-over study showed that the transnasal EGD was slightly more tolerable than the transoral EGD in gagging episodes, choking and overall evaluation. [Conclusion]Transnasal EGD was safe with few adverse effects on cardiopulmonary function and was more tolerable than transoral EGD.

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The efficacy of argon plasma coagulation (APC) for superficial squamous cell carcinoma and dysplasia of the esophagus was investigated. Twenty-nine patients (31 lesions) with primary superficial squamous cell carcinoma and dysplasia of the esophagus were treated by APC. First, the extent of the lesion was confirmed by conventional endoscopy and iodine staining. Second, marking of the edge of the lesion by APC probe and biopsy was performed. Then, APC treatment was performed. Repeated APC was done if recurrence or a residual lesion was confirmed by follow up endoscopy. Twenty-one superficial carcinomas and 10 areas of dysplasia were treated. The average lesion diameter was 17.4 mm (5-40mm) and the average number of APC treatments was 1.3 (1-4). There were no severe complications. The average duration of follow-up was 17.4 months. Although recurrence or residual lesions were found in 5 patients, repeated APC achieved control in all of them. It seems that APC can be used safely to treat superficial squamous cell carcinoma and dysplasia of the esophagus. APC can be repeated multiple times, if necessary. Follow-up is needed after APC, because some cases of recurrence were experienced.

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A 74-years old male who was pointed out atypical lymphocytes in mucosal specimen sampled from gastric erosion was introduced to our hospital for further evaluation. Initial endoscopic examination revealed erosive change with H. pylori-associated gastritis. Triple therapy for H. pylori was then performed and successfully eradicated. 2^nd endoscopy (3M later) revealed irregular gastric ulcer but no malignancy was histologically detected. However, type 2-like ulcer lesion appeared at 3^rd endoscopic examination (6M later). Histological examination revealed deep infiltration of CD30-positive atypical lymphocytes. Since lymphoma lesion was not detected in the other organ, we diagnosed anaplastic large cell lymphoma (ALCL) with gastric origin. ALCL originated from gastrointestinal tract is reportedly rare in non-Hodgikin T-cell lymphomas. Although malignant transformation of gastric B-cell MALT lymphoma after H. pylori-eradication therapy has been reported, rapid development of ALCL after H. pylori-eradication has not been reported so far.

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A 50-year-old man was admitted to the local hospital because of the injury of cervical vertebrae and steroid pulse therapy was performed. After that, he began to have tarry stool and endoscopic examination revealed a small duodenal ulcer at the second portion. There was not active bleeding, so conservative treatment was undergone. But anemia progressed gradually. Endoscopic examination was performed again, and arterial bleeding from the duodenal ulcer was noticed, so he was petened to our hospital. Emergency angiography showed the bleeding from a branch of inferior pancreaticoduodenal artery, therefore arterial embolization was performed. After that, endoscopic examination disclosed denuded vessel at the oral side of the clip. I clipped on this vessel. The course after clipping was uneventful. duodenal ulcer at the second portion is very rare. It would be important that appropriate treatment for each case is selected.

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A 61-year-old Japanese male developed acute abdomen after drinking too much and was admitted to our hospital. Severe acute pancreatitis was diagnosed. A month after this admission, he complained of abdominal pain and frequent vomiting . A plain abdominal film showed an ileus. On colonoscopy, an inflamatory stenosis was presented in the transverse colon that did not permit the scope to pass. The stenotic portion consisted of edematous, reddish mucosa without erosions or ulcer. Endoscopic balloon dilation (outer diameter 30mm, with the over the wire balloon used for treating achalasia) was done twice a 1-week interval between procedures. The stenosis improved without the need for surgery.

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The patient was a 56-year-old male developing a hemorrhagic pancreatic pseudocyst from chronic pancreatitis of the uncinate process. Hemorrhage from the main papilla was observed endoscopically. Endoscopic retrograde cholangiopancreatography revealed a communication between the collapsed area of the accessory pancreatic duct and the pseudocyst. A stent was placed in the caudal pancreatic duct so that it bridged the collapsed area from the accessory papilla using a nasopancreatic drainage tube. The patient improved in symptoms and has been followed up on without any recurrence of symptoms. In some patients with hemorrhagic pseudocysts, there are no obvious pseudo aneurysms as in our case. For these select patients, endoscopic pancreatic stent placement should be regarded as the primary treatment of choice for pseudocyst of the pancreatic head, because surgical treatment is more invasive.

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We retrospectively evaluated transpapillary biopsy and brushing cytology for the diagnosis of pancreatic carcinoma. Those procedures were consecutively performed in the cases that ERCP showed the main pancreatic duct stenosis or obstruction. The subjects are 163 of 385 cases of pancreatic carcinomas, which underwent at least one transpapillary biopsy or brushing cytology. We performed endoscopic pancreatic biopsy (EPB) in 145 of 163 pancreatic car cinomas from April 1997 to March 2006, brushing cytology in 74 of 163. The cancer-positive rate in EPB was 32% (46/145) and in brushing cytology was 65% (48/74). Overall cancerpositive rate in any of those procedures was 48% (79/163). But brushing cytology cancerpositive rate was recently improved to 72% (33/46) after the cytotechnologist was participated in the procedure for immediate interpretation of the cytology. Pancreatitis was occurred in 9% (15/163) as a complication, which was conservatively treated and recovered in all the cases.

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In aged patients with incapable of laparotomy, the main indications of percutaneous endoscopic cecostomy (PEC) are acute colonic psudoobstruction, megacolon, chronic colonic psudoobstruction, and stenosis of malignant lesion. Method and logic of PEC was based on evidence of operative cecostomy for drainage and technique of percutaneous endoscopic gastrostomy. There are two techniques of PEC : introducer method and pull method. In the case for drainage and ACE, introducer method must be used with catheter of 15 French . PEC must be implemented more carefully than PEG, although the method of PEC is similar as PEG. For fixing of the cecum to the abdominal wall, 3 to 4 points were sutured and fastened to the abdominal wall. The main complications are bleeding and growth of granulation tissue.

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Many patients with cancers of oral cavity, oropharynx, hypopharynx and larynx have been diagnosed at an advanced stage because the clinical symptom is often obscure. Although the endoscopists guide the endoscopy through oral and laryngopharyngeal regions at the time of upper digestive endoscopy examination, it has been difficult to detect superficial squamous cell carcinoma. Narrow band imaging (NBI), combined with magnified observation, clearly enhances the microvascular structure of the mucosal surface. NBI is a promising and potentially powerful tool for identifying early stage carcinomas during a routine endoscopic examination. Recently, effectiveness of NBI for detection of the superficial squamous cell carcinoma in the oral cavity, oropharynx and hypopharynx has been reported. Screening utilizing NBI combined with magnified observation may make it possible to reduce the number of patients who have to lose their speaking and swallowing function following a radical surgery. If more early stage cancers can be detected by this screen, the prognosis of oral and laryngopharyngeal cancers might be improved in the near future. We describe herein the tip of conducting proper screening using NBI combined with magnified observation. We also present three cases showing typical images under NBI endoscope to help the better understanding of this new field.

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Near-infrared rays, because of its limited scattering characteristics and low absorption by water and hemoglobin, can penetrate deeply into tissue. Using infrared rays, we have developed an infrared electronic endoscope system and evaluated its usefulness for assessing the depth of involvement of gastric cancers. Recently, we developed a new infrared videoendoscopic system (dual wave-length system). With this system, we can recognize submucosal vessels of gastric cancers in a greater detail with higher resolution under IR light. A total of 30 patients with depressed gastric cancers underwent infrared endoscopy. Twenty one (91%) of 23 intramucosal and submucosal cancers less than 1, 000um were observed as tumors with no stain or faint stain, whereas all (100%) of 7 more invasive cancers were observed as tumors with dense stain or pooling of the dye. Thus, the over all accuracy was 93% (28 of 30 tumors). Moreover, 95% (18 of 19) of tumors with ulcerative changes were correctly diagnosed. New infrared electronic endoscopic system is useful for diagnosing the depth of involvement of early gastric cancer either with or without ulcerative changes. This system will bring us further development in the diagnosis of gastric cancer.

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