- Email: [email protected]
Endoscopic histology: the start of a new era?
Digestive and Liver Disease 36 (2004) 251–252
Commentary
Endoscopic histology: the start of a new era? P. Sharma∗ Department of Veterans Affairs Medical Center, University of Kansas School of Medicine, 4801 E. Linwood Blvd., Kansas City, MO 64128-2295, USA See related article on pages 286–291
The diagnosis of active and chronic gastritis, intestinal metaplasia, Helicobacter pylori infection and dysplasia in the stomach depends on obtaining random biopsies within the gastric antrum and body. The distribution of these lesions within the gastric mucosa is usually patchy and random biopsies could easily miss focal lesions present within the stomach. Moreover, obtaining biopsies is associated with definitive costs, processing times, as well as the variability in the interpretation of dysplasia especially in disease states such as inflammatory bowel disease and Barrett’s oesophagus. Due to these limitations, new techniques have been utilised in an attempt to maximise the sensitivity and overall accuracy of endoscopy and biopsy for the diagnosis of inflammation, metaplasia and dysplasia. The use of new technology such as magnification endoscopy with or without chromoendoscopy (i.e. dye spraying) offers the ability to examine in detail the stomach mucosa which is not visible by conventional endoscopy, thus, potentially leading to targeted biopsies. Chromoendoscopy employs chemical staining agents applied to the gastrointestinal mucosa to identify specific mucosal subtypes or to highlight surface characteristics of the epithelium that are most likely to contain areas of dysplasia or early cancer. Magnification endoscopes provide a “zoom” or “magnified” view of a specific area under evaluation. The concept of using a combination of staining with either high-resolution/magnification endoscopy to allow accurate identification of both intestinal metaplasia and dysplasia due to differences in observed mucosal patterns has been explored in recent studies. From the first reported use of magnifying endoscopes in the late 1970s to recently published reports of ultra-high magnification endoscopy, magnification endoscopes provide a wide range of magnification capabilities [1,2]. Fine vascular network and intrapapillary
∗
Tel.: +1-816-861-4700x6735. E-mail address: [email protected] (P. Sharma).
loops have been described with the use of ultra-high magnification endoscopes by Inoue et al. In this issue of Digestive and Liver Disease, Kim et al. [3] report on the use of magnification endoscopy in 176 patients including 53 who had a prior history of H. pylori infection with subsequent eradication therapy. These patients were evaluated with a magnifying endoscope with a capability of 80× magnification when viewed by a 15 in. TV monitor. Chromoendoscopy with indigo carmine, a contrast stain, was used in conjunction with the magnification procedure. The investigators observed four specific type of pit patterns within the antrum of the stomach recorded by two separate endoscopists with a surprisingly high kappa value of 0.906. The authors noted that type 1 and type 2 mucosal patterns correlated with normal mucosa, whereas active inflammation and intestinal metaplasia were associated with type 3 and type 4 mucosal pit patterns, respectively. Magnification chromoendoscopy had an excellent sensitivity and specificity of 96.3 and 73.7%, respectively, in diagnosing gastritis as opposed to conventional endoscopy which had a sensitivity and specificity of only 66 and 52.9%, respectively. Notably, the investigators were also able to determine that the majority of patients who had been successfully eradicated for H. pylori infection had type 1 and type 2 mucosal patterns. Although this is a preliminary study conducted in a high risk population with a high inter-observer agreement on the recognition of patterns, it highlights the need for further evaluation of these technologies within the gastrointestinal tract, which would ultimately move us away from obtaining random biopsies by highlighting areas of high risk. Similar studies have been conducted on patients with inflammatory bowel disease and Barrett’s oesophagus [4,5]. In combination with chromoendoscopy, high-resolution or magnification endoscopes can potentially increase the diagnostic yield of clinically relevant lesions and preliminary data have indicated a good correlation of findings to
1590-8658/$30 – see front matter © 2004 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.dld.2004.01.001
252
P. Sharma / Digestive and Liver Disease 36 (2004) 251–252
histopathological readings. A number of other investigators have reported different mucosal pit patterns either in the oesophagus, stomach or the colon [6,7]. Chromoendoscopy and magnification/high-resolution endoscopy are used routinely in Japan. However, they have still not been widely accepted elsewhere in the world and according to a recent questionnaire, chromoendoscopy is utilised relatively infrequently in Western countries. Before magnification endoscopy with chromoendoscopy becomes standard practice especially in the era of cost effectiveness, a number of questions should be addressed. Among these are: Does it improve outcomes? Is it cost effective? What is the target population? Nonetheless, such and other emerging technologies will change our current practices and will have a major impact on screening and surveillance of different pre-neoplastic lesions of the gastrointestinal tract. As a first step, a uniform nomenclature and classification system needs to be devised. Once this has been done, investigators throughout the world can utilise a standardised classification system and the results could be more generalised and also provide an opportunity for the training of endoscopists in a simple, validated classification system. A number of drawbacks of using these techniques currently exist, including the cost of the endoscope, the additional time required to perform the procedure as well as the small areas which are visualised using magnification endoscopy. Moreover, we should “train the trainers” since a majority of the Western endoscopists do not routinely use and there is no formal “education” on the use of new and emerging techniques. In conclusion, new techniques to improve the accuracy of endoscopic diagnosis as well as identifying patients at high risk for neoplasia development have recently been developed, and most of them are currently being evaluated in clinical studies. The results with these techniques although promising, are still preliminary. They hold promise for the improved detection of inflammatory lesions, H. pylori infection, dysplasia and neoplasia at an early stage of their development, with a greater chance for early treatment, and so a greater likelihood of either cure or prevention. If val-
idated, these techniques may become an important tool for the practising gastroenterolgists. There is obviously a need for more research in this field. Large scale clinical trial will be required to determine their true potential in gastrointestinal diseases. Conflict of interest statement I, Prateek Sharma, have received grant support from Olympus Inc.
Acknowledgements Supported by the Veterans Affairs Medical Center, Kansas City, MO and The American Gastroenterological Association (AGA) Castell Esophageal Clinical Research Award. References [1] Kubo K, Fujino M. Ultra-high magnification endoscopy of the normal esophageal mucosa. Gastrointest Endosc 1997;46:96–7. [2] Inoue H, Honda T, Yoshida T. Ultra-high magnification endoscopy of the normal esophageal mucosa. Dig Endosc 1996;2:134–8. [3] Kim S, Haruma K, Ito M, Tanaka S, Yoshihara M, Chayama K. Magnifying gastroendoscopy for diagnosis of histologic gastritis in the gastric antrum. Dig Liver Dis 2004;36:286–91. [4] Sharma P, Weston AP, Topalovski M, Cherian R, Bhattaacharyya A, Sampliner RE. Magnification chromoendoscopy for the detection of intestinal metaplasia and dysplasia in Barrett’s esophagus. Gut 2003;52:24–7. [5] Kiesslich R, Fritsch J, Holtmann M, Koehler H, Stolte M, Kanzler S, et al. Methylene blue-aided chromoendoscopy for the detection of intraepithelial neoplasia and colon cancer in ulcerative colitis. Gastroenterology 2003;124:880–8. [6] Jaramillo E, Watanabe M, Befrits R, Ponce de Leon E, Rubino C, Slezak P. Small, flat colorectal neoplasias in long-standing ulcerative colitis detected by high-resolution electronic video endoscopy. Gastrointest Endosc 1996;44:15–22. [7] Connor M, Sharma P. Chromoendoscopy and magnification endoscopy in Barrett’s esophagus. In: Sharma P, editor. Gastrointestinal endoscopy clinics of North America, Barrett’s esophagus. Part I. Diagnosis, vol. 13. 2003. p. 269–77.
Commentary
Endoscopic histology: the start of a new era? P. Sharma∗ Department of Veterans Affairs Medical Center, University of Kansas School of Medicine, 4801 E. Linwood Blvd., Kansas City, MO 64128-2295, USA See related article on pages 286–291
The diagnosis of active and chronic gastritis, intestinal metaplasia, Helicobacter pylori infection and dysplasia in the stomach depends on obtaining random biopsies within the gastric antrum and body. The distribution of these lesions within the gastric mucosa is usually patchy and random biopsies could easily miss focal lesions present within the stomach. Moreover, obtaining biopsies is associated with definitive costs, processing times, as well as the variability in the interpretation of dysplasia especially in disease states such as inflammatory bowel disease and Barrett’s oesophagus. Due to these limitations, new techniques have been utilised in an attempt to maximise the sensitivity and overall accuracy of endoscopy and biopsy for the diagnosis of inflammation, metaplasia and dysplasia. The use of new technology such as magnification endoscopy with or without chromoendoscopy (i.e. dye spraying) offers the ability to examine in detail the stomach mucosa which is not visible by conventional endoscopy, thus, potentially leading to targeted biopsies. Chromoendoscopy employs chemical staining agents applied to the gastrointestinal mucosa to identify specific mucosal subtypes or to highlight surface characteristics of the epithelium that are most likely to contain areas of dysplasia or early cancer. Magnification endoscopes provide a “zoom” or “magnified” view of a specific area under evaluation. The concept of using a combination of staining with either high-resolution/magnification endoscopy to allow accurate identification of both intestinal metaplasia and dysplasia due to differences in observed mucosal patterns has been explored in recent studies. From the first reported use of magnifying endoscopes in the late 1970s to recently published reports of ultra-high magnification endoscopy, magnification endoscopes provide a wide range of magnification capabilities [1,2]. Fine vascular network and intrapapillary
∗
Tel.: +1-816-861-4700x6735. E-mail address: [email protected] (P. Sharma).
loops have been described with the use of ultra-high magnification endoscopes by Inoue et al. In this issue of Digestive and Liver Disease, Kim et al. [3] report on the use of magnification endoscopy in 176 patients including 53 who had a prior history of H. pylori infection with subsequent eradication therapy. These patients were evaluated with a magnifying endoscope with a capability of 80× magnification when viewed by a 15 in. TV monitor. Chromoendoscopy with indigo carmine, a contrast stain, was used in conjunction with the magnification procedure. The investigators observed four specific type of pit patterns within the antrum of the stomach recorded by two separate endoscopists with a surprisingly high kappa value of 0.906. The authors noted that type 1 and type 2 mucosal patterns correlated with normal mucosa, whereas active inflammation and intestinal metaplasia were associated with type 3 and type 4 mucosal pit patterns, respectively. Magnification chromoendoscopy had an excellent sensitivity and specificity of 96.3 and 73.7%, respectively, in diagnosing gastritis as opposed to conventional endoscopy which had a sensitivity and specificity of only 66 and 52.9%, respectively. Notably, the investigators were also able to determine that the majority of patients who had been successfully eradicated for H. pylori infection had type 1 and type 2 mucosal patterns. Although this is a preliminary study conducted in a high risk population with a high inter-observer agreement on the recognition of patterns, it highlights the need for further evaluation of these technologies within the gastrointestinal tract, which would ultimately move us away from obtaining random biopsies by highlighting areas of high risk. Similar studies have been conducted on patients with inflammatory bowel disease and Barrett’s oesophagus [4,5]. In combination with chromoendoscopy, high-resolution or magnification endoscopes can potentially increase the diagnostic yield of clinically relevant lesions and preliminary data have indicated a good correlation of findings to
1590-8658/$30 – see front matter © 2004 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.dld.2004.01.001
252
P. Sharma / Digestive and Liver Disease 36 (2004) 251–252
histopathological readings. A number of other investigators have reported different mucosal pit patterns either in the oesophagus, stomach or the colon [6,7]. Chromoendoscopy and magnification/high-resolution endoscopy are used routinely in Japan. However, they have still not been widely accepted elsewhere in the world and according to a recent questionnaire, chromoendoscopy is utilised relatively infrequently in Western countries. Before magnification endoscopy with chromoendoscopy becomes standard practice especially in the era of cost effectiveness, a number of questions should be addressed. Among these are: Does it improve outcomes? Is it cost effective? What is the target population? Nonetheless, such and other emerging technologies will change our current practices and will have a major impact on screening and surveillance of different pre-neoplastic lesions of the gastrointestinal tract. As a first step, a uniform nomenclature and classification system needs to be devised. Once this has been done, investigators throughout the world can utilise a standardised classification system and the results could be more generalised and also provide an opportunity for the training of endoscopists in a simple, validated classification system. A number of drawbacks of using these techniques currently exist, including the cost of the endoscope, the additional time required to perform the procedure as well as the small areas which are visualised using magnification endoscopy. Moreover, we should “train the trainers” since a majority of the Western endoscopists do not routinely use and there is no formal “education” on the use of new and emerging techniques. In conclusion, new techniques to improve the accuracy of endoscopic diagnosis as well as identifying patients at high risk for neoplasia development have recently been developed, and most of them are currently being evaluated in clinical studies. The results with these techniques although promising, are still preliminary. They hold promise for the improved detection of inflammatory lesions, H. pylori infection, dysplasia and neoplasia at an early stage of their development, with a greater chance for early treatment, and so a greater likelihood of either cure or prevention. If val-
idated, these techniques may become an important tool for the practising gastroenterolgists. There is obviously a need for more research in this field. Large scale clinical trial will be required to determine their true potential in gastrointestinal diseases. Conflict of interest statement I, Prateek Sharma, have received grant support from Olympus Inc.
Acknowledgements Supported by the Veterans Affairs Medical Center, Kansas City, MO and The American Gastroenterological Association (AGA) Castell Esophageal Clinical Research Award. References [1] Kubo K, Fujino M. Ultra-high magnification endoscopy of the normal esophageal mucosa. Gastrointest Endosc 1997;46:96–7. [2] Inoue H, Honda T, Yoshida T. Ultra-high magnification endoscopy of the normal esophageal mucosa. Dig Endosc 1996;2:134–8. [3] Kim S, Haruma K, Ito M, Tanaka S, Yoshihara M, Chayama K. Magnifying gastroendoscopy for diagnosis of histologic gastritis in the gastric antrum. Dig Liver Dis 2004;36:286–91. [4] Sharma P, Weston AP, Topalovski M, Cherian R, Bhattaacharyya A, Sampliner RE. Magnification chromoendoscopy for the detection of intestinal metaplasia and dysplasia in Barrett’s esophagus. Gut 2003;52:24–7. [5] Kiesslich R, Fritsch J, Holtmann M, Koehler H, Stolte M, Kanzler S, et al. Methylene blue-aided chromoendoscopy for the detection of intraepithelial neoplasia and colon cancer in ulcerative colitis. Gastroenterology 2003;124:880–8. [6] Jaramillo E, Watanabe M, Befrits R, Ponce de Leon E, Rubino C, Slezak P. Small, flat colorectal neoplasias in long-standing ulcerative colitis detected by high-resolution electronic video endoscopy. Gastrointest Endosc 1996;44:15–22. [7] Connor M, Sharma P. Chromoendoscopy and magnification endoscopy in Barrett’s esophagus. In: Sharma P, editor. Gastrointestinal endoscopy clinics of North America, Barrett’s esophagus. Part I. Diagnosis, vol. 13. 2003. p. 269–77.