Takuji Yamasaki

Variable stiffness colonoscopes are associated with less pain during colonoscopy in unsedated patients

OBJECTIVES:Application of a new variable stiffness colonoscope (VSC) is expected to control loop formation and to lessen patient discomfort. The aim of this prospective study was to compare the efficacy of VSC with a conventional colonoscope (CC) in unsedated colonoscopy, based on the experience of examiners.METHODS:Four-hundred sixty-seven patients were randomly assigned to undergo colonoscopy with either VSC or CC by an endoscopist, including experienced and less-experienced examiners. The percentages of completed procedure and time to cecal intubation were recorded. Patients were asked to rate pain on a 5-point pain score.RESULTS:The percentages of completed procedure with VSC and CC were 98% and 95%, respectively, by less-experienced hands, and 99% and 98%, respectively, by experienced hands. Time for cecal intubation with VSC and CC was 15.7 and 18.5 min, respectively, by less-experienced hands, and 9.8 and 10.6 min, respectively, by experienced hands. A significantly lower mean pain score was noted in VSC patients compared with CC patients, irrespective of experience of the examiner. The percent of patients rating the procedure as moderately or severely painful was significantly lower with VSC than with CC, both in less-experienced (19% vs 40%; p < 0.01) and experienced hands (15% vs 26%; p < 0.05).CONCLUSIONS:Our results indicated that VSC allows favorable examination compared with CC regarding completeness, time to cecal intubation, and comfort of patients undergoing unsedated colonoscopy, irrespective of the examiners experience. These features suggest VSC as the preferred colonoscope for patients undergoing unsedated colonoscopy.

EMR of upper GI lesions when using a novel soft, irrigation, prelooped hood

BACKGROUND EMR with a cap-fitted endoscope, including a soft, prelooped hood, is a useful, effective, and safe technique. One problem with this method, however, is that the lesion cannot always be kept in the center of the cap because the procedure is performed blindly after aspiration. A soft, prelooped hood with attached irrigation tube was developed. The usefulness of this device for EMR of upper-GI intramucosal cancers was evaluated. METHODS The end-hood piece was fabricated by drilling a side hole in the cap portion of a conventional soft, prelooped hood and then attaching an irrigation tube with glue to the exterior surface of the hole. The fabricated transparent hood was placed at the tip of an endoscope, and aspiration mucosectomy under irrigation was performed in 15 patients with upper-GI intramucosal cancer. When the field of view at the aspiration site was obscured by oozing blood, the site was irrigated. RESULTS A satisfactory view was obtained of all lesions. The mean diameter of specimens was 24.5 mm (interquartile range: 15-35). The proportion of en bloc resected lesions was 86.7% (13/15). Bleeding was the only complication (4/15; 26.7%) and was controlled by using endoscopic hemostatic techniques under irrigation. CONCLUSIONS EMR when using the soft, prelooped hood with irrigation tube is effective and safe for intramucosal cancers 20 mm or less in diameter.

PSEUDOMALIGNANT EROSION IN HYPERPLASTIC POLYP AT ESOPHAGO‐GASTRIC JUNCTION

To the Editor, Generally, the hyperplastic polyp of the stomach must be considered to be a benign lesion. We have observed atypical changes, like malignancy, in the stroma of one hyperplastic polyp located at the esophago-gastric junction (EGJ). A 70-year-old man, with no history of non-steroidal anti-inflammatory drug use and prior hematemesis, visited our hospital because of melena and concomitant severe anemia. He had been subjected to a subtotal gastrectomy 25 years ago. Upper gastrointestinal endoscopy revealed a polyp, shell-shaped, at the EGJ and no other lesions in the remnant stomach. The head of the polyp was formed out of white-coated ulcer and erosion (Fig. 1a). Microscopic findings of the biopsy specimen taken from the gastric polyp demonstrated fragments of elongated hyperplastic foveolar epithelium and inflamed granulation tissue with large cells having basophilic cytoplasm and large hyperchromatic nuclei containing prominent nucleoli, associated with necrotic slough peripherally. Nuclear pleomorphism and mitotic figures were seen (Fig. 1b). Immunohistochemically, the large cells were negative for anticytomegalovirus, antiherpes simplex virus antibodies and cytokeratins (CAM5.2, AE1/AE3), while they were positively reactive to vimentin. Based on these findings, the patient was suspected to have stromal atypia in the remnants of polypoid lesion at the EGJ and so an endoscopic mucosal resection (EMR) of the whole polyp was performed. Histologically, the resected polypoid lesion proved to be hyperplasia of foveolar epithelia with moderate chronic inflammation and edema of the stroma. In the regional polypoid lesion, there was inflamed granulation tissue with large cells having basophilic cytoplasm and large hyperchromatic nuclei containing prominent nucleoli, associated with erosion and necrotic debris. There was no evidence of malignancy. The resected polypoid lesion was hyperplastic polyp, so this case was diagnosed as hyperplastic polyp with pseudomalignant erosion. Follow-up of this patient, ranging in duration of 2 years, disclosed no evidence of recurrence. We have described a polypoid lesion with a distinctive histological appearance associated with ulceration and erosion, which locates at the EGJ. Endoscopic features, white coated and reddish mucosa of the top of the polyp, suggested a malignant lesion. Histologically, some stromal cells have striking atypical form, like occasional mitotic figures. It is difficult to make the differential diagnosis (DD) of this polyp with its endoscopic and histological appearance of a malignancy. The DD includes viral infection, lymphoma, poorly differentiated carcinoma, spindle cell carcinoma, and sarcoma. Although the large atypical cells have a superficial resemblance to cells infected with cytomegarovirus, typically cytomegalovirus-infected cells have a large intranuclear halo and, not infrequently, intracytoplasmic inclusions. There is absence of characteristic features of their malignancy and cytomegalovirus infection in this case.

Gastrointestinal : Inflammatory myoglandular polyp of the colon

An inflammatory myoglandular polyp of the large bowel is a rare but distinct clinical entity that was first described by Dr S Nakamura and others in 1992. It is characterized histologically by inflammatory granulation tissue in the lamina propria, proliferation of smooth muscle and hyperplastic glands which sometimes show cystic dilatation. The typical endoscopic appearance is that of a pedunculated spherical polyp with a smooth surface and patchy redness that resembles a ripe strawberry. There may also be a patchy mucous exudate. Thus far, only a small number of cases have been reported and the pathogenesis and natural history remain unclear. We describe the endoscopic and histological findings of an inflammatory myoglandular polyp in the distal transverse colon. A 42-year-old Japanese man was investigated because of a positive fecal occult blood test. Barium enema radiographs revealed two colonic polyps: one in the distal transverse colon and one in the sigmoid colon. At colonoscopy, the polyp in the transverse colon was approximately 10 mm in diameter with a spherical shape, pedunculated base and a smooth surface as shown in Figure 1. Red areas were noted on the surface of the polyp. Histological evaluation revealed hyperplastic glands and an inflamed and widened fibromuscular stroma with lymphoid follicles (Fig. 2; HE ×25). The appearance was consistent with an inflammatory myoglandular polyp. The polyp in the sigmoid colon was a small tubular adenoma. Inflammatory myoglandular polyps need to be distinguished from Peutz-Jegher-type polyps, juvenile polyps, inflammatory polyps, inflammatory cap polyps, and polyps associated with mucosal prolapse, sometimes involving colostomy sites.

Multiple hepatic infarction after transcatheter arterial infusion with SMANCS

We report a patient with hepatocellular carcinoma who developed multiple hepatic infarction after transcatheter arterial infusion (TAI) with a suspension of styrene maleic acid neocarzinostatin (SMANCS) and Lipiodol (SMANCS/Lipiodol). The parameters of hepatic functional reserve were apparently decreased after the second TAI with SMANCS/Lipiodol, and the patient died of hepatic failure 103 days after the second TAI. The autopsy liver specimen revealed multiple hepatic infarctions associated with peripheral arterial stenosis or occlusion, and portal thrombosis. It is speculated that both the arterial occlusion and the portal thrombosis caused the hepatic infarction, based on a long-term insufficiency of blood supply to the hepatocytes arising from toxic arteritis caused by SMANCS/Lipiodol.