Comparison between tunneling and standard endoscopic submucosal dissection for treatment of large esophageal superficial neoplasm.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) has been established as a standard endoscopic method for treating esophageal superficial neoplasms, and it can be performed using a conventional or a tunneling method. The aim of the present study was to compare the safety and efficacy of tunneling ESD (t-ESD) and standard ESD (s-ESD) for treating large esophageal superficial neoplasms and to explore the risk factors for postoperative strictures. PATIENTS AND METHODS: Fifty-five consecutive patients with large esophageal superficial neoplasms were treated by t-ESD or s-ESD. Demographics, lesion characteristics, procedure-related parameters, and follow-up results were retrospectively collected to compare the efficacy and safety of these procedures. Multivariate analyses were conducted to determine the potential risk factors for postoperative strictures. RESULTS: Of the 55 patients, 13 underwent t-ESD and 42 underwent s-ESD. The dissection speed of t-ESD was significantly faster than that of s-ESD (7.42±1.99 min/cm2 vs. 9.01±2.11 min/cm2, P<0.05). En bloc resection was achieved in 98.2% (54/55) of the cases, while R0 resection was achieved in 92.7% (51/55). Curative resection was achieved in 78.2% (43/55) of the cases. Fourteen patients (25.5%) had postoperative strictures, which resolved with endoscopic dilation and/or stent insertion. Circumferential involvement of >3/4 and lesion length of >3 cm were independent risk factors for strictures. CONCLUSIONS: T-ESD is a safe and effective method for treating large esophageal superficial neoplasms with a faster dissection speed than s-ESD, but postoperative strictures may be encountered for lesions involving more than three-fourths of the circumference or longer than 3 cm.

The inhibitory effect of melatonin on colonic motility disorders induced by water avoidance stress in rats.

OBJECTIVES: Psychological stress is involved in the etiology of functional gastrointestinal disease (FGID). Accumulations of chronic continuous stress associate with the symptoms of the gastrointestinal tract (GIT) including abdominal discomfort, pain, constipation or diarrhea. Melatonin (MT) is a neurohormone which mainly synthesized in the pineal gland and GIT, has been shown to alleviate the stress and regulate the intestinal motility. Although melatonin attenuated abnormal defecation induced by stress, the mechanisms of the effect are not fully elucidated. This study sought to investigate the effect of melatonin (MT) on colonic smooth muscle contractility disorders induced by chronic water avoidance stress (WAS). MATERIALS AND METHODS: 36 adult Wistar rats were divided into three groups [Control+V (vehicle solution), WAS+V, WAS+MT]. The WAS+V and WAS+MT groups were suffered from WAS for one hour daily for 10 days. Melatonin was given 30 min before stress session in the WAS+MT group. Colonic motility was assessed using the numbers of fecal pellet output. The concentrations of melatonin and serotonin (5-HT) were measured through ELISA method. The contractions of isolated colonic strips were assessed through isometric force transducer. RESULTS: The numbers of fecal output was increased in the WAS+V group, and melatonin attenuates the increased fecal pellet output induced by WAS. The concentrations of 5-HT was increased by WAS, and melatonin decreased the augment in the concentration of 5-HT. In the part of contraction recording of colonic smooth muscle, melatonin inhibited the fortified spontaneous contraction induced by WAS, and decreased the amplitude of spontaneous contraction stimulated by Ach and KCl after WAS treatment. CONCLUSIONS: Melatonin could inhibit WAS-induced fecal output pellets by inactivating the 5-HT pathway, may interact with calcium channel and inhibit the influx of calcium.