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Amyloidoma of the Esophagus

TO THE EDITOR: We read with interest the article by Park et al. in the November issue of this journal (1). We applaud their efforts to highlight the possibility of implementing a small-caliber scope to achieve individualized and successful colonoscopy, especially with the current global need for screening for colorectal cancer. However, we would like to add constructive comments on this study. In this single-operator study, the colonoscopy withdrawal time was not mentioned. Adequate withdrawal time has been suggested to decrease the adenoma miss rate (2, 3), and at least 6 min of withdrawal time is recommended (3). In addition, the authors did not clarify whether a one-man maneuver or two-man maneuver was adopted in colonoscopic insertion, since a two-man maneuver is still popular in many Asian countries. Comparison of the use of a two-man maneuver with a standard colonoscope and the use of a one-man maneuver with an upper endoscope may exaggerate the advantage of the upper endoscope. Likewise, the question of whether a small-caliber upper endoscope (9.2 mm) can be inadvertently withdrawn faster than a large-caliber standard colonoscope (12.2 mm) remains to be answered. Another question concerns patients with past histories of abdominal or pelvic surgery. Kozarek et al. have reported the usefulness of a small-caliber endoscope after unsuccessful standard colonoscopy because of stenosis or angulation (4). It would be interesting to see the comparative performance in these specific subgroups to test a potentially beneficial role of an upper endoscope in these patients. In this study, multivariate logistic regression analysis revealed three independent predictors of painful colonoscopy: using an upper endoscope, female gender, and lower BMI. Our previous work has similarities and dissimilarities with this study (5, 6). Patient characteristics are similar and so is the number of polyps detected in each examinee (1.7 per examinee in our study) (5). In our previous prospective study on the factors determining postcolonoscopy abdominal pain (6), female gender similarly increased the likelihood of postcolonoscopy abdominal pain, as did the duration of colonoscopy. However, BMI (23.76 ± 3.29 kg/m2 in our participants) did not contribute significantly to pain in our study. A major dissimilarity is that up to 88% of our colonoscopies were under conscious sedation in a screening setting. Application of this study to all colonoscopists might have some limitations since only one operator was included (1). As cases of colorectal cancers are increasing worldwide, more studies and discussions on high-quality colonoscopy for individualized patients are certainly needed. Yet, the evidence for routine use of an upper endoscope in colonoscopy may still be too sparse to utilize. Tsung-Chun Lee, M.D.1 Han-Mo Chiu, M.D.2 Yi-Chia Lee, M.D.2 Hsiu-Po Wang, M.D.3 Shih-Pei Huang, M.D., Ph.D.2 Ming-Shiang Wu, M.D., Ph.D.2 Jaw-Town Lin, M.D., Ph.D.2 1Department of Internal Medicine National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan Departments of 2Internal Medicine and 3Emergency Medicine, National Taiwan University Hospital and College of Medicine National Taiwan University Taipei, Taiwan