Title: Novel Zoom Endoscopy Technique for Visualizing the Microvascular Architecture in Gastric Mucosa
Abstract: We have developed and established a zoom endoscopy technique based on visualization of the mucosal microvascular architecture in units as small as the capillary in the normal stomach and early gastric cancer. With regard to the microvascular architecture of the normal stomach, the findings differed according to the section of the stomach. The gastric body showed a honeycomb-like subepithelial capillary network pattern with collecting venule, whereas the gastric antrum showed a coil-shaped subepithelial capillary network pattern. Regarding early gastric cancer, the following findings seemed to be specific for differentiated carcinoma: (1) a demarcation line between the cancerous and the noncancerous mucosa, (2) the disappearance of the regular subepithelial capillary network pattern, and (3) the presence of an irregular microvascular pattern. These findings, which were visualized by magnified observation, could be useful in clinical practice when we attempt to make a correct endoscopic diagnosis of flat reddened lesions (gastritis vs cancer) and when we attempt to determine the precise horizontal margin of early gastric cancer. This could help us to perform successful endoscopic resection based on endoscopic findings alone. In conclusion, our zoom endoscopy for visualizing the microvascular architecture in gastric mucosa could be a new system for diagnosing early gastric cancer. We have developed and established a zoom endoscopy technique based on visualization of the mucosal microvascular architecture in units as small as the capillary in the normal stomach and early gastric cancer. With regard to the microvascular architecture of the normal stomach, the findings differed according to the section of the stomach. The gastric body showed a honeycomb-like subepithelial capillary network pattern with collecting venule, whereas the gastric antrum showed a coil-shaped subepithelial capillary network pattern. Regarding early gastric cancer, the following findings seemed to be specific for differentiated carcinoma: (1) a demarcation line between the cancerous and the noncancerous mucosa, (2) the disappearance of the regular subepithelial capillary network pattern, and (3) the presence of an irregular microvascular pattern. These findings, which were visualized by magnified observation, could be useful in clinical practice when we attempt to make a correct endoscopic diagnosis of flat reddened lesions (gastritis vs cancer) and when we attempt to determine the precise horizontal margin of early gastric cancer. This could help us to perform successful endoscopic resection based on endoscopic findings alone. In conclusion, our zoom endoscopy for visualizing the microvascular architecture in gastric mucosa could be a new system for diagnosing early gastric cancer. Since 2000, we have been using an upper-gastrointestinal zoom endoscope1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar to observe the gastric mucosal microvasculature in units as small as the capillary. We have reported several magnified endoscopic findings of the microvascular architecture in both normal gastric mucosa and early gastric cancer.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 2Yao K. Oishi T. Mastui T. et al.Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.Gastrointest Endosc. 2002; 56: 279-284Abstract Full Text Full Text PDF PubMed Scopus (217) Google Scholar, 3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar, 4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 5Yao K. Yao T. Iwashita A. Determining the horizontal extent of early gastric carcinoma two modern techniques based on differences in the mucosal microvascular architecture and density between carcinomatous and non-carcinomatous mucosa.Dig Endosc. 2004; 14: S83-S87Crossref Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar In this article, we review these microvascular findings and describe their clinical usefulness.MethodsEndoscopic Equipment and ProcedureAn upper-gastrointestinal zoom endoscope (GIF-Q240Z; Olympus, Tokyo, Japan) and an electronic endoscopic system, either the EVIS 240 series (Olympus) or the EVIS 260 series (Olympus), were used. The preparation of the patients is the same as before routine upper-gastrointestinal endoscopy. The only difference is the use of a hood that is mounted on the tip of the scope before the examination, thereby enabling the endoscopist to fix the focal distance at 3 mm between the tip of the scope and the gastric mucosa. During endoscopic examination, if the endoscopist finds a lesion of interest by ordinary (nonmagnified) observation, the hood that covers the tip of the scope is allowed to touch the lesion immediately after zooming up to the maximal magnifying level, through the use of a manual zooming attachment. A magnified endoscopic image which is in focus at a maximal magnification in focus can be obtained easily.Microvascular Architecture of the Noninflamed Gastric MucosaThe microvascular architecture of the stomach free from pathologic change (such as chronic gastritis associated with Helicobacter pylori) shows 2 distinct patterns depending on the region of the stomach.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarIn the gastric body, mucosa shows a regular honeycomb-like subepithelial capillary network (SECN) pattern with collecting venule: a polygonal-shaped subepithelial capillary loop surrounds each pit and each capillary forms a network in a regular arrangement. This capillary network drains into a collecting venule. If the gastric mucosa is free from pathologic change, then this honeycomb-like SECN pattern with a collecting venule is identified consistently in a regular arrangement.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarThe gastric antral mucosa shows a regular coil-shaped SECN pattern located in the apical parts, which are elevated relatively between the antral gastric sulci and pits, and each capillary forms a subepithelial network in a regular arrangement. This SECN pattern rarely is accompanied by a collecting venule because the collecting venule in the antral mucosa is located anatomically in a deeper part under the epithelium.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarMicrovascular Architecture of Early Gastric Cancer and Noncancerous MucosaWe previously reported the microvascular architecture of intramucosal gastric cancer as observed by magnified endoscopy in vivo.2Yao K. Oishi T. Mastui T. et al.Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.Gastrointest Endosc. 2002; 56: 279-284Abstract Full Text Full Text PDF PubMed Scopus (217) Google Scholar All the noncancerous mucosa that surrounds the cancerous mucosa consistently shows the regular SECN pattern (Figure 1). However, the characteristics of microvascular architecture are quite different depending on the types of histologic differentiation. In differentiated carcinoma (Figure 2), the regular SECN pattern is replaced by microvessels that are irregular in both shape and arrangement. There is a clear demarcation line between cancerous and noncancerous mucosa.Figure 2Magnified endoscopic view of the carcinomatous mucosa of early gastric cancer (superficial depressed type). At the margin of the carcinoma, the regular SECN pattern has disappeared at a demarcation line (arrows) and microvessels that are irregular in both shape and arrangement have proliferated within the cancerous mucosa (irregular microvascular pattern).View Large Image Figure ViewerDownload (PPT)On the other hand, in undifferentiated carcinoma, the carcinomatous mucosa only shows the disappearance of or a reduced pattern of the surrounding regular SECN.Clinical Application of Zoom Endoscopy Early Gastric CancerThe microvascular findings of differentiated carcinoma seem to be specific for making a diagnosis of diffferentiated carcinoma based on magnified endoscopic findings alone. Accordingly, we applied this novel zoom endoscopy technique to clinical practice and conducted several studies.3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar, 4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 5Yao K. Yao T. Iwashita A. Determining the horizontal extent of early gastric carcinoma two modern techniques based on differences in the mucosal microvascular architecture and density between carcinomatous and non-carcinomatous mucosa.Dig Endosc. 2004; 14: S83-S87Crossref Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google Scholar We hereby introduce our most recent findings obtained during two clinical investigation.4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google ScholarMaking the Correct Diagnosis of Gastric Flat Reddened Mucosal Lesions (Gastritis Versus Gastric Cancer)When performing screening endoscopy, flat reddened lesions are frequently encountered. To diagnose a flat, small early gastic cancer, numerous biopsies are taken from any such lesion, which means that a correct diagnosis is usually made based on histopathological, and not endoscopic, findings. We prospectively investigated the diagnostic accuracy of magnified endoscopic findings for differentiating between reddened mucosa caused by gastritis and flat reddened gastric cancer in 485 patients. The characteristics for differentiated carcinoma described earlier were recorded. Pathologically, 136 flat reddened lesions showed only gastritis, whereas 51 lesions were diagnosed as differentiated carcinoma. The incidence for each of the magnified endoscopic findings is summarized in Table 1. The difference in the prevalence of the presence of an irregular microvascular pattern between gastritis and cancer was the most remarkable finding. The irregular microvascular pattern for differentiating cancer from gastritis had a sensitivity of 98% and a specificity of 99% in cases in which the only apparent finding was a flat reddened lesion.Table 1The Prevalence of the Magnified Endoscopic Findings of 187 Flat Reddened LesionsDemarcation lineDisappearance of SECNIrregular microvascular patternGastritis24.3%21.3%.7% (95% CI)(17.1%–31.5%)(14.4%–28.2%)(0%–2.1%)Gastric cancer94.1%100%98.0% (95% CI)(87.6%–100%)(94.2%–100%)Data from 136 gastritis lesions and 51 gastric cancer lesions.CI, confidence interval. Open table in a new tab Determining the Precise Margin of the Intramucosal Extent of Early Gastric Cancer To Perform the Endoscopic Submucosal Dissection Technique SuccessfullyThe endoscopic submucosal dissection technique is the most useful method for performing curative endoscopic resection of early gastric carcinoma because the carcinoma can be resected together with an adequate surgical safety margin en bloc.3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar To perform successful resection, however, it is essential to determine the margin of the cancer correctly. We prospectively investigated the usefulness of zoom endoscopy for preoperative evaluation of the horizontal margin of the cancer.Forty-seven early gastric cancers of differentiated type were included in the study. All the cancers were examined by the zoom upper-gastrointestinal endoscope. According to subsequent observation after the nonmagnified observation, all the demarcation lines between the cancerous and the noncancerous mucosa had been identified. Then, several markings were made on the mucosa a few millimeters outside the demarcation lines by electrocoagulation. The cancerous mucosa, together with all the markings, subsequently was resected by the endoscopic submucosal dissection method. According to the histopathological investigation of the resected specimen, we investigated whether or not the horizontal cut ends were free from carcinomatous tissue, and whether or not the markings had been placed correctly outside the carcinomatous mucosa.Forty-three cancers were resected en bloc and 3 cancers were resected in 2–8 pieces. Only 1 of the horizontal margins of 1 specimen of the 43 cancers that had been resected en bloc showed positive findings for cancerous tissue. All the margins of the remaining 42 lesions showed negative findings for cancerous tissue and all the markings were located outside the boundary of the cancerous tissue. This suggests that zoom endoscopy visualizes differences in the microvascular architecture between carcinomatous and noncarcinomatous mucosa, identifying the margin of early gastric carcinomas, allowing for safe resection by the endoscopic submucosal dissection method.DiscussionThe clinical application of zoom endoscopy to examine the gastric mucosa could be successfully achieved due to the following 3 reasons. First, technologically, the upper GI zoom endoscope has the same size and operability as those of the ordinary endoscope. Second, the use of a hood at the tip of the scope enabled the endoscopist to fix the focal distance at maximal magnification easily. In contrast, aortic pulsation, respiration, and peristalsis often disturb the endoscopist from obtaining a fixed focal image of the gastric mucosa. Third, there had not been specific markers or guidelines for describing magnified endoscopic findings until we found markers based on microvascular architecture, that is an irregular microvascular pattern in cancerous mucosa, the regular SECN pattern in noncancerous mucosa, and a demarcation line between cancerous and noncancerous mucosa.As described in this article, we can now easily identify both normal gastric mucosal microvascular architecture and the characteristic microvascular architecture in gastric cancer, in vivo, by the newly established zoom endoscopy technique. In addition, this technique has advantages over other magnified endoscopy techniques, in that it is not necessary to introduce any artificial materials (such as dye) into the human body. In the future, we anticipate this novel zoom endoscopy technique based on mucosal microvascular architecture will be applied to many other clinical investigations, such as functional analysis of the gastric mucosal microcirculation as well as the diagnosis of early carcinoma. In conclusion, the novel zoom technique seems likely to become a new diagnostic endoscopic system for diagnosing early gastric cancer. Since 2000, we have been using an upper-gastrointestinal zoom endoscope1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar to observe the gastric mucosal microvasculature in units as small as the capillary. We have reported several magnified endoscopic findings of the microvascular architecture in both normal gastric mucosa and early gastric cancer.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 2Yao K. Oishi T. Mastui T. et al.Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.Gastrointest Endosc. 2002; 56: 279-284Abstract Full Text Full Text PDF PubMed Scopus (217) Google Scholar, 3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar, 4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 5Yao K. Yao T. Iwashita A. Determining the horizontal extent of early gastric carcinoma two modern techniques based on differences in the mucosal microvascular architecture and density between carcinomatous and non-carcinomatous mucosa.Dig Endosc. 2004; 14: S83-S87Crossref Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar In this article, we review these microvascular findings and describe their clinical usefulness. MethodsEndoscopic Equipment and ProcedureAn upper-gastrointestinal zoom endoscope (GIF-Q240Z; Olympus, Tokyo, Japan) and an electronic endoscopic system, either the EVIS 240 series (Olympus) or the EVIS 260 series (Olympus), were used. The preparation of the patients is the same as before routine upper-gastrointestinal endoscopy. The only difference is the use of a hood that is mounted on the tip of the scope before the examination, thereby enabling the endoscopist to fix the focal distance at 3 mm between the tip of the scope and the gastric mucosa. During endoscopic examination, if the endoscopist finds a lesion of interest by ordinary (nonmagnified) observation, the hood that covers the tip of the scope is allowed to touch the lesion immediately after zooming up to the maximal magnifying level, through the use of a manual zooming attachment. A magnified endoscopic image which is in focus at a maximal magnification in focus can be obtained easily.Microvascular Architecture of the Noninflamed Gastric MucosaThe microvascular architecture of the stomach free from pathologic change (such as chronic gastritis associated with Helicobacter pylori) shows 2 distinct patterns depending on the region of the stomach.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarIn the gastric body, mucosa shows a regular honeycomb-like subepithelial capillary network (SECN) pattern with collecting venule: a polygonal-shaped subepithelial capillary loop surrounds each pit and each capillary forms a network in a regular arrangement. This capillary network drains into a collecting venule. If the gastric mucosa is free from pathologic change, then this honeycomb-like SECN pattern with a collecting venule is identified consistently in a regular arrangement.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarThe gastric antral mucosa shows a regular coil-shaped SECN pattern located in the apical parts, which are elevated relatively between the antral gastric sulci and pits, and each capillary forms a subepithelial network in a regular arrangement. This SECN pattern rarely is accompanied by a collecting venule because the collecting venule in the antral mucosa is located anatomically in a deeper part under the epithelium.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarMicrovascular Architecture of Early Gastric Cancer and Noncancerous MucosaWe previously reported the microvascular architecture of intramucosal gastric cancer as observed by magnified endoscopy in vivo.2Yao K. Oishi T. Mastui T. et al.Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.Gastrointest Endosc. 2002; 56: 279-284Abstract Full Text Full Text PDF PubMed Scopus (217) Google Scholar All the noncancerous mucosa that surrounds the cancerous mucosa consistently shows the regular SECN pattern (Figure 1). However, the characteristics of microvascular architecture are quite different depending on the types of histologic differentiation. In differentiated carcinoma (Figure 2), the regular SECN pattern is replaced by microvessels that are irregular in both shape and arrangement. There is a clear demarcation line between cancerous and noncancerous mucosa.On the other hand, in undifferentiated carcinoma, the carcinomatous mucosa only shows the disappearance of or a reduced pattern of the surrounding regular SECN. Endoscopic Equipment and ProcedureAn upper-gastrointestinal zoom endoscope (GIF-Q240Z; Olympus, Tokyo, Japan) and an electronic endoscopic system, either the EVIS 240 series (Olympus) or the EVIS 260 series (Olympus), were used. The preparation of the patients is the same as before routine upper-gastrointestinal endoscopy. The only difference is the use of a hood that is mounted on the tip of the scope before the examination, thereby enabling the endoscopist to fix the focal distance at 3 mm between the tip of the scope and the gastric mucosa. During endoscopic examination, if the endoscopist finds a lesion of interest by ordinary (nonmagnified) observation, the hood that covers the tip of the scope is allowed to touch the lesion immediately after zooming up to the maximal magnifying level, through the use of a manual zooming attachment. A magnified endoscopic image which is in focus at a maximal magnification in focus can be obtained easily. An upper-gastrointestinal zoom endoscope (GIF-Q240Z; Olympus, Tokyo, Japan) and an electronic endoscopic system, either the EVIS 240 series (Olympus) or the EVIS 260 series (Olympus), were used. The preparation of the patients is the same as before routine upper-gastrointestinal endoscopy. The only difference is the use of a hood that is mounted on the tip of the scope before the examination, thereby enabling the endoscopist to fix the focal distance at 3 mm between the tip of the scope and the gastric mucosa. During endoscopic examination, if the endoscopist finds a lesion of interest by ordinary (nonmagnified) observation, the hood that covers the tip of the scope is allowed to touch the lesion immediately after zooming up to the maximal magnifying level, through the use of a manual zooming attachment. A magnified endoscopic image which is in focus at a maximal magnification in focus can be obtained easily. Microvascular Architecture of the Noninflamed Gastric MucosaThe microvascular architecture of the stomach free from pathologic change (such as chronic gastritis associated with Helicobacter pylori) shows 2 distinct patterns depending on the region of the stomach.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarIn the gastric body, mucosa shows a regular honeycomb-like subepithelial capillary network (SECN) pattern with collecting venule: a polygonal-shaped subepithelial capillary loop surrounds each pit and each capillary forms a network in a regular arrangement. This capillary network drains into a collecting venule. If the gastric mucosa is free from pathologic change, then this honeycomb-like SECN pattern with a collecting venule is identified consistently in a regular arrangement.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google ScholarThe gastric antral mucosa shows a regular coil-shaped SECN pattern located in the apical parts, which are elevated relatively between the antral gastric sulci and pits, and each capillary forms a subepithelial network in a regular arrangement. This SECN pattern rarely is accompanied by a collecting venule because the collecting venule in the antral mucosa is located anatomically in a deeper part under the epithelium.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar The microvascular architecture of the stomach free from pathologic change (such as chronic gastritis associated with Helicobacter pylori) shows 2 distinct patterns depending on the region of the stomach.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar In the gastric body, mucosa shows a regular honeycomb-like subepithelial capillary network (SECN) pattern with collecting venule: a polygonal-shaped subepithelial capillary loop surrounds each pit and each capillary forms a network in a regular arrangement. This capillary network drains into a collecting venule. If the gastric mucosa is free from pathologic change, then this honeycomb-like SECN pattern with a collecting venule is identified consistently in a regular arrangement.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 8Yagi K. Nakumura A. Seike A. et al.[Endoscopic features of the normal gastric mucosa without Helicobacter pylori infection].Gastroenterol Endosc. 2000; 42: 1977-1987Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar The gastric antral mucosa shows a regular coil-shaped SECN pattern located in the apical parts, which are elevated relatively between the antral gastric sulci and pits, and each capillary forms a subepithelial network in a regular arrangement. This SECN pattern rarely is accompanied by a collecting venule because the collecting venule in the antral mucosa is located anatomically in a deeper part under the epithelium.1Yao K. Oishi T. Microgastroscopic findings of mucosal microvascular architecture as visualized by magnifying endoscopy.Dig Endosc. 2001; 13: S27-S33Crossref Google Scholar, 7Yao K. Gastric microvascular architecture as visualized by magnifying endoscopy body mucosa and antral mucosa without pathological change demonstrate two different patterns of microvascular architecture.Gastrointest Endosc. 2004; 59: 596-597Abstract Full Text Full Text PDF PubMed Google Scholar, 9Nakagawa S. Kato M. Shimizu Y. et al.Relationship between histopathologic gastritis and mucosal microvascularity observations with magnifying endoscopy.Gastrointest Endosc. 2003; 58: 71-75Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar Microvascular Architecture of Early Gastric Cancer and Noncancerous MucosaWe previously reported the microvascular architecture of intramucosal gastric cancer as observed by magnified endoscopy in vivo.2Yao K. Oishi T. Mastui T. et al.Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.Gastrointest Endosc. 2002; 56: 279-284Abstract Full Text Full Text PDF PubMed Scopus (217) Google Scholar All the noncancerous mucosa that surrounds the cancerous mucosa consistently shows the regular SECN pattern (Figure 1). However, the characteristics of microvascular architecture are quite different depending on the types of histologic differentiation. In differentiated carcinoma (Figure 2), the regular SECN pattern is replaced by microvessels that are irregular in both shape and arrangement. There is a clear demarcation line between cancerous and noncancerous mucosa.On the other hand, in undifferentiated carcinoma, the carcinomatous mucosa only shows the disappearance of or a reduced pattern of the surrounding regular SECN. We previously reported the microvascular architecture of intramucosal gastric cancer as observed by magnified endoscopy in vivo.2Yao K. Oishi T. Mastui T. et al.Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.Gastrointest Endosc. 2002; 56: 279-284Abstract Full Text Full Text PDF PubMed Scopus (217) Google Scholar All the noncancerous mucosa that surrounds the cancerous mucosa consistently shows the regular SECN pattern (Figure 1). However, the characteristics of microvascular architecture are quite different depending on the types of histologic differentiation. In differentiated carcinoma (Figure 2), the regular SECN pattern is replaced by microvessels that are irregular in both shape and arrangement. There is a clear demarcation line between cancerous and noncancerous mucosa. On the other hand, in undifferentiated carcinoma, the carcinomatous mucosa only shows the disappearance of or a reduced pattern of the surrounding regular SECN. Clinical Application of Zoom Endoscopy Early Gastric CancerThe microvascular findings of differentiated carcinoma seem to be specific for making a diagnosis of diffferentiated carcinoma based on magnified endoscopic findings alone. Accordingly, we applied this novel zoom endoscopy technique to clinical practice and conducted several studies.3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar, 4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 5Yao K. Yao T. Iwashita A. Determining the horizontal extent of early gastric carcinoma two modern techniques based on differences in the mucosal microvascular architecture and density between carcinomatous and non-carcinomatous mucosa.Dig Endosc. 2004; 14: S83-S87Crossref Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google Scholar We hereby introduce our most recent findings obtained during two clinical investigation.4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google ScholarMaking the Correct Diagnosis of Gastric Flat Reddened Mucosal Lesions (Gastritis Versus Gastric Cancer)When performing screening endoscopy, flat reddened lesions are frequently encountered. To diagnose a flat, small early gastic cancer, numerous biopsies are taken from any such lesion, which means that a correct diagnosis is usually made based on histopathological, and not endoscopic, findings. We prospectively investigated the diagnostic accuracy of magnified endoscopic findings for differentiating between reddened mucosa caused by gastritis and flat reddened gastric cancer in 485 patients. The characteristics for differentiated carcinoma described earlier were recorded. Pathologically, 136 flat reddened lesions showed only gastritis, whereas 51 lesions were diagnosed as differentiated carcinoma. The incidence for each of the magnified endoscopic findings is summarized in Table 1. The difference in the prevalence of the presence of an irregular microvascular pattern between gastritis and cancer was the most remarkable finding. The irregular microvascular pattern for differentiating cancer from gastritis had a sensitivity of 98% and a specificity of 99% in cases in which the only apparent finding was a flat reddened lesion.Table 1The Prevalence of the Magnified Endoscopic Findings of 187 Flat Reddened LesionsDemarcation lineDisappearance of SECNIrregular microvascular patternGastritis24.3%21.3%.7% (95% CI)(17.1%–31.5%)(14.4%–28.2%)(0%–2.1%)Gastric cancer94.1%100%98.0% (95% CI)(87.6%–100%)(94.2%–100%)Data from 136 gastritis lesions and 51 gastric cancer lesions.CI, confidence interval. Open table in a new tab Determining the Precise Margin of the Intramucosal Extent of Early Gastric Cancer To Perform the Endoscopic Submucosal Dissection Technique SuccessfullyThe endoscopic submucosal dissection technique is the most useful method for performing curative endoscopic resection of early gastric carcinoma because the carcinoma can be resected together with an adequate surgical safety margin en bloc.3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar To perform successful resection, however, it is essential to determine the margin of the cancer correctly. We prospectively investigated the usefulness of zoom endoscopy for preoperative evaluation of the horizontal margin of the cancer.Forty-seven early gastric cancers of differentiated type were included in the study. All the cancers were examined by the zoom upper-gastrointestinal endoscope. According to subsequent observation after the nonmagnified observation, all the demarcation lines between the cancerous and the noncancerous mucosa had been identified. Then, several markings were made on the mucosa a few millimeters outside the demarcation lines by electrocoagulation. The cancerous mucosa, together with all the markings, subsequently was resected by the endoscopic submucosal dissection method. According to the histopathological investigation of the resected specimen, we investigated whether or not the horizontal cut ends were free from carcinomatous tissue, and whether or not the markings had been placed correctly outside the carcinomatous mucosa.Forty-three cancers were resected en bloc and 3 cancers were resected in 2–8 pieces. Only 1 of the horizontal margins of 1 specimen of the 43 cancers that had been resected en bloc showed positive findings for cancerous tissue. All the margins of the remaining 42 lesions showed negative findings for cancerous tissue and all the markings were located outside the boundary of the cancerous tissue. This suggests that zoom endoscopy visualizes differences in the microvascular architecture between carcinomatous and noncarcinomatous mucosa, identifying the margin of early gastric carcinomas, allowing for safe resection by the endoscopic submucosal dissection method. The microvascular findings of differentiated carcinoma seem to be specific for making a diagnosis of diffferentiated carcinoma based on magnified endoscopic findings alone. Accordingly, we applied this novel zoom endoscopy technique to clinical practice and conducted several studies.3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar, 4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 5Yao K. Yao T. Iwashita A. Determining the horizontal extent of early gastric carcinoma two modern techniques based on differences in the mucosal microvascular architecture and density between carcinomatous and non-carcinomatous mucosa.Dig Endosc. 2004; 14: S83-S87Crossref Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google Scholar We hereby introduce our most recent findings obtained during two clinical investigation.4Yao K. Iwashita A. Haraoka S. et al.Novel zoom-endoscopy technique for visualizing the mucosal microvascular architecture is useful for making a correct diagnosis of gastric reddened flat mucosal lesions (gastritis vs. gastric cancer).Endoscopy. 2004; 35: A6Google Scholar, 6Yao K. Kikuchi Y. Tanabe H. et al.Novel zoom-endoscopy technique for visualizing the microvascular architecture of early gastric cancer enables the precise margin of the cancer to be determined thereby allowing successful resection by the endoscopic submucosal dissection method.Endoscopy. 2004; 36: A6Google Scholar Making the Correct Diagnosis of Gastric Flat Reddened Mucosal Lesions (Gastritis Versus Gastric Cancer)When performing screening endoscopy, flat reddened lesions are frequently encountered. To diagnose a flat, small early gastic cancer, numerous biopsies are taken from any such lesion, which means that a correct diagnosis is usually made based on histopathological, and not endoscopic, findings. We prospectively investigated the diagnostic accuracy of magnified endoscopic findings for differentiating between reddened mucosa caused by gastritis and flat reddened gastric cancer in 485 patients. The characteristics for differentiated carcinoma described earlier were recorded. Pathologically, 136 flat reddened lesions showed only gastritis, whereas 51 lesions were diagnosed as differentiated carcinoma. The incidence for each of the magnified endoscopic findings is summarized in Table 1. The difference in the prevalence of the presence of an irregular microvascular pattern between gastritis and cancer was the most remarkable finding. The irregular microvascular pattern for differentiating cancer from gastritis had a sensitivity of 98% and a specificity of 99% in cases in which the only apparent finding was a flat reddened lesion.Table 1The Prevalence of the Magnified Endoscopic Findings of 187 Flat Reddened LesionsDemarcation lineDisappearance of SECNIrregular microvascular patternGastritis24.3%21.3%.7% (95% CI)(17.1%–31.5%)(14.4%–28.2%)(0%–2.1%)Gastric cancer94.1%100%98.0% (95% CI)(87.6%–100%)(94.2%–100%)Data from 136 gastritis lesions and 51 gastric cancer lesions.CI, confidence interval. Open table in a new tab When performing screening endoscopy, flat reddened lesions are frequently encountered. To diagnose a flat, small early gastic cancer, numerous biopsies are taken from any such lesion, which means that a correct diagnosis is usually made based on histopathological, and not endoscopic, findings. We prospectively investigated the diagnostic accuracy of magnified endoscopic findings for differentiating between reddened mucosa caused by gastritis and flat reddened gastric cancer in 485 patients. The characteristics for differentiated carcinoma described earlier were recorded. Pathologically, 136 flat reddened lesions showed only gastritis, whereas 51 lesions were diagnosed as differentiated carcinoma. The incidence for each of the magnified endoscopic findings is summarized in Table 1. The difference in the prevalence of the presence of an irregular microvascular pattern between gastritis and cancer was the most remarkable finding. The irregular microvascular pattern for differentiating cancer from gastritis had a sensitivity of 98% and a specificity of 99% in cases in which the only apparent finding was a flat reddened lesion. Data from 136 gastritis lesions and 51 gastric cancer lesions. CI, confidence interval. Determining the Precise Margin of the Intramucosal Extent of Early Gastric Cancer To Perform the Endoscopic Submucosal Dissection Technique SuccessfullyThe endoscopic submucosal dissection technique is the most useful method for performing curative endoscopic resection of early gastric carcinoma because the carcinoma can be resected together with an adequate surgical safety margin en bloc.3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar To perform successful resection, however, it is essential to determine the margin of the cancer correctly. We prospectively investigated the usefulness of zoom endoscopy for preoperative evaluation of the horizontal margin of the cancer.Forty-seven early gastric cancers of differentiated type were included in the study. All the cancers were examined by the zoom upper-gastrointestinal endoscope. According to subsequent observation after the nonmagnified observation, all the demarcation lines between the cancerous and the noncancerous mucosa had been identified. Then, several markings were made on the mucosa a few millimeters outside the demarcation lines by electrocoagulation. The cancerous mucosa, together with all the markings, subsequently was resected by the endoscopic submucosal dissection method. According to the histopathological investigation of the resected specimen, we investigated whether or not the horizontal cut ends were free from carcinomatous tissue, and whether or not the markings had been placed correctly outside the carcinomatous mucosa.Forty-three cancers were resected en bloc and 3 cancers were resected in 2–8 pieces. Only 1 of the horizontal margins of 1 specimen of the 43 cancers that had been resected en bloc showed positive findings for cancerous tissue. All the margins of the remaining 42 lesions showed negative findings for cancerous tissue and all the markings were located outside the boundary of the cancerous tissue. This suggests that zoom endoscopy visualizes differences in the microvascular architecture between carcinomatous and noncarcinomatous mucosa, identifying the margin of early gastric carcinomas, allowing for safe resection by the endoscopic submucosal dissection method. The endoscopic submucosal dissection technique is the most useful method for performing curative endoscopic resection of early gastric carcinoma because the carcinoma can be resected together with an adequate surgical safety margin en bloc.3Yao K. Iwashita A. Matsui T. et al.The magnified endoscopic finding of an irregular microvascular pattern is a very useful marker for differentiating between gastritis and gastric cancer a prospective study.Gastrointest Endosc. 2004; 59: AB169Abstract Full Text Full Text PDF Google Scholar To perform successful resection, however, it is essential to determine the margin of the cancer correctly. We prospectively investigated the usefulness of zoom endoscopy for preoperative evaluation of the horizontal margin of the cancer. Forty-seven early gastric cancers of differentiated type were included in the study. All the cancers were examined by the zoom upper-gastrointestinal endoscope. According to subsequent observation after the nonmagnified observation, all the demarcation lines between the cancerous and the noncancerous mucosa had been identified. Then, several markings were made on the mucosa a few millimeters outside the demarcation lines by electrocoagulation. The cancerous mucosa, together with all the markings, subsequently was resected by the endoscopic submucosal dissection method. According to the histopathological investigation of the resected specimen, we investigated whether or not the horizontal cut ends were free from carcinomatous tissue, and whether or not the markings had been placed correctly outside the carcinomatous mucosa. Forty-three cancers were resected en bloc and 3 cancers were resected in 2–8 pieces. Only 1 of the horizontal margins of 1 specimen of the 43 cancers that had been resected en bloc showed positive findings for cancerous tissue. All the margins of the remaining 42 lesions showed negative findings for cancerous tissue and all the markings were located outside the boundary of the cancerous tissue. This suggests that zoom endoscopy visualizes differences in the microvascular architecture between carcinomatous and noncarcinomatous mucosa, identifying the margin of early gastric carcinomas, allowing for safe resection by the endoscopic submucosal dissection method. DiscussionThe clinical application of zoom endoscopy to examine the gastric mucosa could be successfully achieved due to the following 3 reasons. First, technologically, the upper GI zoom endoscope has the same size and operability as those of the ordinary endoscope. Second, the use of a hood at the tip of the scope enabled the endoscopist to fix the focal distance at maximal magnification easily. In contrast, aortic pulsation, respiration, and peristalsis often disturb the endoscopist from obtaining a fixed focal image of the gastric mucosa. Third, there had not been specific markers or guidelines for describing magnified endoscopic findings until we found markers based on microvascular architecture, that is an irregular microvascular pattern in cancerous mucosa, the regular SECN pattern in noncancerous mucosa, and a demarcation line between cancerous and noncancerous mucosa.As described in this article, we can now easily identify both normal gastric mucosal microvascular architecture and the characteristic microvascular architecture in gastric cancer, in vivo, by the newly established zoom endoscopy technique. In addition, this technique has advantages over other magnified endoscopy techniques, in that it is not necessary to introduce any artificial materials (such as dye) into the human body. In the future, we anticipate this novel zoom endoscopy technique based on mucosal microvascular architecture will be applied to many other clinical investigations, such as functional analysis of the gastric mucosal microcirculation as well as the diagnosis of early carcinoma. In conclusion, the novel zoom technique seems likely to become a new diagnostic endoscopic system for diagnosing early gastric cancer. The clinical application of zoom endoscopy to examine the gastric mucosa could be successfully achieved due to the following 3 reasons. First, technologically, the upper GI zoom endoscope has the same size and operability as those of the ordinary endoscope. Second, the use of a hood at the tip of the scope enabled the endoscopist to fix the focal distance at maximal magnification easily. In contrast, aortic pulsation, respiration, and peristalsis often disturb the endoscopist from obtaining a fixed focal image of the gastric mucosa. Third, there had not been specific markers or guidelines for describing magnified endoscopic findings until we found markers based on microvascular architecture, that is an irregular microvascular pattern in cancerous mucosa, the regular SECN pattern in noncancerous mucosa, and a demarcation line between cancerous and noncancerous mucosa. As described in this article, we can now easily identify both normal gastric mucosal microvascular architecture and the characteristic microvascular architecture in gastric cancer, in vivo, by the newly established zoom endoscopy technique. In addition, this technique has advantages over other magnified endoscopy techniques, in that it is not necessary to introduce any artificial materials (such as dye) into the human body. In the future, we anticipate this novel zoom endoscopy technique based on mucosal microvascular architecture will be applied to many other clinical investigations, such as functional analysis of the gastric mucosal microcirculation as well as the diagnosis of early carcinoma. In conclusion, the novel zoom technique seems likely to become a new diagnostic endoscopic system for diagnosing early gastric cancer. The authors wish to thank Miss Katherine Miller (Royal English Language Centre, Fukuoka, Japan) for correcting the English used in this manuscript.
Publication Year: 2005
Publication Date: 2005-07-01
Language: en
Type: review
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 64
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