A Study On The Diagnosis Of Barrett's Esophagus By EPK-I

BackgroundThe definition of Barrett's esophagus(BE) is the replacement of stratified squamous epithelium in the distal esophagus by simple columnar epithelium with or without columnar metaplasia according to the Consensus Draft on the Diagnosis and Treatment of BE(Chongqing, China, 2005). BE with specialized columnar metaplasia was considered as precancerosis of esophageal adenocarcinoma. There is no specific symptom with BE. The common symptoms are related to gastroesophageal reflux, such as heart burn, acid regurgitation, chest pain and dysphagia and so on. The diagnosis of BE depends on endoscopy and esophageal mucosa biopsy. Determinations of squamoucolumnar junction(SCJ) and gastroesophageal junction(GEJ) are important in the endoscopic diagnosis of BE. The typical endoscopic appearances of BE are: existence of orange columnar epithelium proximal to GEJ, representing separation of SCJ and GEJ. There are long-lasting controversies in the endoscopic diagnosis of BE, hence many BE patients have different levels of hyperemia, edema, erosion and some even ulcer, hyperplasia, stricture and/or hiatal hernia, which make it difficult to identify the positions of SCJ and GEJ, and accurate biopsies are impossible in many cases.The revised standard of Japanese Esophageal Disease Research Society in 2000 suggested paliform blood vessels appearing in space between SCJ and GEJ as the first evidence of endoscopic BE. When paliform blood vessels could not be identified, the followings were suggested: a. discrepancies of superficial mucosa(margin of mucosal venation); b. the proximal end of gastric mucosal fold. But the discrepancy of superfical mucosa is obscure, which might lead to variations between observers. And identification of proximal end of gastric mucosal fold could also be affected by inflation. The paliform blood vessels might be the only visible mark for the diagnosis of BE and practically guide biopsy. Observation of paliform blood vessels between SCJ and GEJ is important in the diagnosis of BE.EPK-i was the newly developed endoscopic processor unit by PENTAX. The EPK-i equipment in this study was equiped with EPK-i endoscopic processor unit and newly endoscope 90i with 3 million pixels camera.The advantages of the new ensocope over ordinary electronic endoscope are: 1. Camera with 3 million pixels capability. 2. Totally digitizing processor, with surface enhancement, contrast enhancement, and boundary enrichment, which all could be processed with immediately displayed on screen. 3. Sharper static pictrues. 4. Brighter pictures with 300 watt xenon vapor lamp and 3 watt booster diode lamp. 5. Triple digitial zooming function. 6. Five levels of suction strenth available in need.The aim of this study is to evaluate the diagnostic value of EPK-i in BE compared with ordinary electronic endoscope.ObjectiveTo evaluate the diagnostic value of EPK-i endoscope in BE.MethodsWe selected 400 patients with reflux esphageal disease who had typical reflux symptoms, which included heart burn, acid regurgitation, chest pain and dysphagia. The total VAS must exceed 10. The patients were randomized into 2 groups. Two hundred of them received EPK-i and the others received ordinary electronic endoscope. Those suspected as BE were observed closely and sampled according to four quadrant biopsy. The detection rate and diagnostic accuracy were compared between two endoscopes.ResultsThere was no significant difference in detection rates of BE between EPK-i and ordinary electronic endoscope(p>=0. Ob), of which 12.50% and 7.50% respectively. The dection rate of EPK-i in short BE with typical reflux symptoms was 10.50%, higher than 5.0% of ordinary endoscope. There was no significant difference between EPK-i and ordinary endoscope, of which 2.00% and 2.50% respectively. The misdiagnosis rate of EPK-i(6.50%) was similar to ordinary endoscope(7.00%) for BE with typical reflux symptoms. The dection rates of EPK-i in tongue and circumference type BE(6.50%, 9.50%) were both higher than ordinary endoscope(1.50%, 3.50%). The detection rate of paliform blood vessels between SCJ and GEJ was higher using EPK-i than ordinary endoscope(8.50% versus 3.50%, p<0.05). Those with endoscopic visible paliform blood vessels are more coincident with pathology than those without(92.31% versus 39.02%, p<0.05). And we found BE is more prevalent in males. The patients' symptoms included abnominal distention, pain under xiphoid bone, hawk except for the reflux symptoms of heart burn, chest pain, acid regurgitation and dysphagia. The rate of dysplasia is higher in specialised columnar metaplasia BE(75.00%) than gastic fundus type( 11.11 %) and boundary type(20.0%).ConclusionsThere is no significant superiority of EPK-i over ordinary endoscope in dection of BE in those with typical reflux symptoms, but EPK-i might be valuable for dection of short, tongue and circumference BE. EPK-i could also play an important role in the observation of paliform blood vessels between SCJ and GEJ in BE.