Shinji Tanaka

Clinicopathologic and endoscopic features of colorectal serrated adenoma: differences between polypoid and superficial types.

BACKGROUND Serrated adenoma is a distinct histologic colorectal lesion. There are two macroscopic types: polypoid and superficial. The aim of this study was to clarify clinicopathologic and endoscopic differences between polypoid and superficial serrated adenomas. METHODS An analysis was conducted of the clinicopathologic and endoscopic features for 240 polypoid and 127 superficial serrated adenomas examined by colonoscopy, and the surface pit patterns of 114 polypoid and 64 superficial serrated adenomas examined by magnifying videoendoscopy. RESULTS The male:female gender ratio for the polypoid serrated adenomas (3.5:1) was significantly higher than that for the superficial serrated adenomas (1.7:1). Superficial serrated adenomas were significantly larger than polypoid serrated adenomas (mean [standard deviation], respectively, 10.1 [7.9] mm vs. 6.3 [4.6] mm). In the distal segments of the colorectum, polypoid serrated adenomas were more common than superficial serrated adenomas. Granulonodular and lobular appearances at endoscopy were significantly more common for polypoid (23.3%) than for superficial serrated adenomas (7.1%). Pit patterns differed between the lesion types: polypoid serrated adenomas had type III(L) or IV pit patterns; all superficial serrated adenomas had the type II pit pattern. The relative frequency of occurrence of high-grade dysplasia and carcinoma in situ among superficial serrated adenomas (25.2%) was significantly greater than that among polypoid serrated adenomas (9.2%). The tubulovillous growth pattern was significantly more common in polypoid tumors (31.5%) than in superficial tumors (0%). CONCLUSIONS Polypoid and superficial serrated adenomas have different clinicopathologic characteristics and growth patterns.

Necessity of Multiple Gastric Biopsies from Different Sites for Detection of Clarithromycin-Resistant Helicobacter pylori Strains

BACKGROUND It has been reported that approximately 10% of patients infected with Helicobacter pylori have both clarithromycin-susceptible and clathromycin-resistant strains. However, there have been no reports indicating whether only one gastric biopsy is sufficient to detect clarithromycin-resistant strains. METHODS Sixty-five H. pylori-infected patients were selected for this study, and 40 of them were given clarithromycin-based eradication therapy. Four gastric biopsies, 2 from the antrum and 2 from the corpus, were obtained from each of the 65 patients. Susceptibility of H. pylori strains to clarithromycin was examined by detecting mutations of the 23S ribosomal RNA (rRNA) gene of H. pylori. RESULTS The clarithromycin-resistant strains were detected in 16 of the 65 (25%) patients. Only 5 of the 16 (31%) patients had the resistant strains in both the antrum and corpus. When only 1 or the other biopsy from the antrum was used, the resistant strains were detected in 8 (50%) or 9 (56%) of the 16 patients. CONCLUSIONS These data indicate that multiple gastric biopsies from both the antrum and the corpus should be used to detect clarithromycin-resistant H. pylori strains.Background: It has been reported that ~10% of patients infected with Helicobacter pylori have both clarithromycin-susceptible and clathromycin-resistant strains. However, there have been no reports indicating whether only one gastric biopsy is sufficient to detect clarithromycin-resistant strains. Methods: Sixty-five H. pylori -infected patients were selected for this study, and 40 of them were given clarithromycin-based eradication therapy. Four gastric biopsies, 2 from the antrum and 2 from the corpus, were obtained from each of the 65 patients. Susceptibility of H. pylori strains to clarithromycin was examined by detecting mutations of the 23S ribosomal RNA (rRNA) gene of H. pylori. Results: The clarithromycin-resistant strains were detected in 16 of the 65 (25%) patients. Only 5 of the 16 (31%) patients had the resistant strains in both the antrum and corpus. When only 1 or the other biopsy from the antrum was used, the resistant strains were detected in 8 (50%) or 9 (56%) of the 16 patients. Conclusions: These data indicate that multiple gastric biopsies from both the antrum and the corpus should be used to detect clarithromycin-resistant H. pylori strains.

Autonomic Nerve Dysfunction is Closely Associated with the Abnormalities of Esophageal Motility in Reflux Esophagitis

Background: While reflux esophagitis (RE) is often associated with esophageal motility dysfunction, the causes of this abnormal motility are not well understood. The aim of our study was to assess the relationship between esophageal motility and autonomic nerve dysfunction by comparing 14 healthy control subjects (11 M, 3 F; mean age, 56.4 years) with 26 patients with RE (19 M, 7 F; mean age, 60.4 years). Methods: According to results of esophageal manometry, subjects with RE were assigned to group I (RE with esophageal motility dysfunction, n = 12) or group N (RE without motility dysfunction, n = 14). Autonomic neuropathy was assessed by measuring the heart rate coefficient of variation at rest (CVR-R), the Valsalva ratio for the R-R interval, the systolic blood pressure response to mental calculation, and the antral contractile response to modified sham feeding (MSF). Results: CVR-R at rest was lower in group I (2.08 ± 0.18) than in group N (3.80 ± 0.44; P < 0.05). The frequency of antral contractile response to MSF per 3-min interval over 15 min was significantly lower in group I than in either group N or controls. The 15-min integrated antral contractile response, taken as the area under the contraction time curve, was much lower in group I (13.2 ± 6.2) than in controls (55.6 ± 9.2; P < 0.01). Conclusions: We conclude that esophageal motor dysfunction in some patients with RE may result from autonomic dysfunction.

Initial experience with catheter probe US when using a multibending endoscope.

BACKGROUND High-frequency catheter probe US provides detailed images when the scanning plane is perpendicular to the area of interest and the latter is within the focal zone. A multibending endoscope has been developed that has two bending sections that can be deflected independently. The aim of this study was to determine whether this new endoscope enhances high-frequency catheter probe US. METHODS High-frequency catheter probe US was performed with the multibending endoscope in 33 patients with upper-GI lesions. The endoscope was carefully maneuvered until the scanning plane was perpendicular to the area of interest and the target area was within the focal zone of the probe. The effects of deflecting the second bending section on the image and on the rotating elements in the probe were evaluated. RESULTS For 28 lesions, no improvement was observed with use of both bending sections. However, for 5 lesions, the US image was improved by use of the second bending section. These lesions were located in the stomach on the lesser or greater curve. In no instance did deflection of both bending sections result in uneven rotation of the mechanical elements in the probe. CONCLUSIONS For certain lesions, US images obtained with a catheter probe can be improved by using an endoscope with a second bending section.

Wide-Area Shape Reconstruction by 3D Endoscopic System Based on CNN Decoding, Shape Registration and Fusion

For effective in situ endoscopic diagnosis and treatment, dense and large areal shape reconstruction is important. For this purpose, we develop 3D endoscopic systems based on active stereo, which projects a grid pattern where grid points are coded by line gaps. One problem of the previous works was that success or failure of 3D reconstruction depends on the stability of feature extraction from the images captured by the endoscope camera. Subsurface scattering or specularities on bio-tissues make this problem difficult. Another problem was that shape reconstruction area was relatively small because of limited field of view of the pattern projector compared to that of the camera. In this paper, to solve the first problem, learning-based approach, i.e., U-Nets, for efficient detection of grid lines and codes at the detected grid points under severe conditions, is proposed. To solve the second problem, an online shape-registration and merging algorithm for sequential frames is proposed. In the experiments, we have shown that we can train U-Nets to extract those features effectively for three specimens of cancers, and also conducted 3D scanning of shapes of a stomach phantom model and a surface inside a human mouth, in which wide-area surfaces are successfully recovered by shape registration and merging.

Strip Biopsy for the Diagnosis and Treatment of Superficial Esophageal Carcinoma and Esophageal Dysplasia

In order to establish a precise pathological diagnosis and to decide the correct approach for esophageal dysplasia or early esophageal cancer, it is desirable to obtain a full thickness mucosal and submucosal biopsy. Strip biopsy has proven to be effective for the treatment and for the diagnosis of flat or sessile lesions of the gastrointestinal tract [1–3]. In this study, we evaluate the efficacy of strip biopsy for the diagnosis and treatment of polypoid or flat lesions of the esophagus.

Natural History of Esophageal Squamous Cell Carcinoma, with Special Reference to Evaluation of Clinical Growth Rate by Tumor Volume Doubling Time

Esophageal carcinoma is a common malignancy with a poor prognosis, despite recent advances in treatment. We previously reported ten patients with rapidly growing squamous cell carcinomas of the esophagus, and showed that the rapid growth of this tumor explains both why it is seldom detected at an early stage and why prognosis is poor [1]. However, reports at variance with our findings have been published [2–4]. In particular, the selection of patients in our previous study may have presented a problem, particularly since the number was small. Moreover, to determine if tumor growth is actually rapid, it is necessary to evaluate tumor growth objectively by comparison with malignancies of other organs.