Endoscopic submucosal dissection for colorectal tumors: technical difficulties and rate of perforation

BACKGROUND AND STUDY AIM

Endoscopic submucosal dissection (ESD) for colorectal tumors is not generally recommended because of the technical difficulties and complications, including perforation. These aspects of ESD are thoroughly analyzed in our retrospective study.

PATIENTS AND METHODS

We studied 105 colorectal tumors, from 100 patients, that were treated by ESD at the Kyoto Prefectural University of Medicine or Nara City Hospital between 2005 and 2008. We analyzed tumor size, operation time, rate of en bloc resection, and complications. In addition, we thoroughly investigated the cases of perforation.

RESULTS

The average tumor size was 30.4 mm; average operation time, 102 min; and rate of en bloc resection, 88.5 %. Perforation occurred in 10.4 % of the ESD procedures. Of the 11 perforations, 8 were detected during ESD and treated by clip closure during endoscopy, while 3 were evident only on subsequent routine computed tomography (CT); these were also managed conservatively. A case of postoperative hemorrhage was also observed.

CONCLUSIONS

ESD effectively achieved a high rate of en bloc resection. However, the perforation rate was substantial; hence, improvement in the ESD method is required. The outcomes of ESD, especially for early colorectal malignancies, need to be assessed further.

Time course of the induction of VGF mRNA in the dorsal vagal complex in rats with cysteamine-induced peptic ulcers

The time course of induction of VGF mRNA in the dorsal vagal complex of the medulla oblongata was investigated in rats with duodenal ulcer induced with cysteamine by in situ hybridization histochemistry. In control rats, weak VGF mRNA signals were detected in a few neurons in the nucleus tractus solitarii and dorsal motor nucleus of vagus. After the cysteamine administration (450 mg/kg, s.c.), VGF mRNA signals began to increase after 3 h, reached at peak level at 12 h, and decreased slightly at 24 h, but remained high after 48 h. The time course of duodenal ulcer score was absent at 3 h, very low at 6 h, about grade 1 at 12 h, and grade 2 or more at 24 and 48 h. The present results support the hypothesis that the increase of the central neuronal activity of the vagus nerve precedes ulcer generation in the duodenum.

Differences of somatostatin mRNA in the rat suprachiasmatic nucleus under light-dark and constant dark conditions: an analysis by in situ hybridization

Daily profiles of somatostatin mRNA expression were investigated in the rat suprachiasmatic nucleus (SCN) by semiquantitative in situ hybridization histochemistry. Under 12 h light/12 h dark conditions, somatostatin mRNA signals were higher during the day time (Zeitgeber time (ZT) 1) than during the night time (ZT 16). This day-night difference was still maintained in constant darkness where the somatostatin mRNA was higher in the subjective day (circadian time (CT) 1) than in the subjective night (CT 16). Together with previous Northern blot hybridization studies, the present observation suggests that the level of somatostatin mRNA in SCN neurons is controlled by the circadian clock, independent of photic environment.

Induction of VGF mRNA in neurons of the rat nucleus tractus solitarius and the dorsal motor nucleus of vagus in duodenal ulceration by cysteamine

To investigate the possible role of the brainstem in cysteamine-induced peptic ulceration, we examined the expression of VGF mRNA, which is induced in PC12 cells following application of nerve growth factor [23], in the nucleus tractus solitarius (NTS)/dorsal motor nucleus of vagus (DMV) complex of the medulla oblongata by in situ hybridization histochemistry. In control saline-treated rats, weak VGF mRNA signals were only rarely detected in neurons of the NTS and none were observed in those in the DMV. After 12 h of cysteamine administration (450 mg/kg, s.c.), the time at which duodenal ulcer was detected in all cases, heavily labeled VGF mRNA-expressing neurons appeared in the NTS and DMV. By quantitative analysis on macroautoradiogram, the VGF mRNA signals of the NTS/DMV complex in cysteamine-treated rats were twice as much as those in saline-treated rats. In situ hybridization histochemistry combined with the use of the retrograde neuronal tracer cholera toxin-B subunit revealed that the induced VGF mRNA-expressing neurons of the DMV projected directly to the stomach. The present results suggest that ulceration accompanies the induction of VGF mRNA in neurons of vagal afferent and efferent areas of the brainstem.

In situ hybridization histochemistry of vgf mRNA in the rat suprachiasmatic nucleus: co-localization with vasopressin/neurophysin and VIP/PHI

The expression of vgf gene, first isolated as a gene induced by nerve growth factor in PC12 cells, was investigated in neurons of the suprachiasmatic nucleus (SCN) by in situ hybridization. In the rat forebrain, the vgf mRNA was found most densely in the SCN. Neurons which express vgf mRNA were found both in the dorsomedial and ventrolateral subdivisions. Soluble-labeling of vgf in situ hybridization and peptide immunocytochemistry demonstrated that vgf mRNA was expressed in most vasopressin- and neurophysin-immunoreactive neurons in the dorsomedial part and in vasoactive intestinal peptide (VIP)- and peptide histidine isoleucine amide (PHI)-immunoreactive neurons in the ventrolateral part. These findings suggest that vgf is a highly expressed gene in both vasopressin/neurophysin neurons and VIP/PHI neurons which were speculated to be involved in the generation and entrainment of circadian rhythm.

In situ hybridization histochemistry of vghm1f mRNA in the rat suprachiasmatic nucleus: co-localization with vasopressin/neurophysin and VIP/PHI

The expression of vgf gene, first isolated as a gene induced by nerve growth factor in PC12 cells, was investigated in neurons of the suprachiasmatic nucleus (SCN) by in situ hybridization. In the rat forebrain, the vgf mRNA was found most densely in the SCN. Neurons which express vgf mRNA were found both in the dorsomedial and ventrolateral subdivisions. Double-labeling of vgf in situ hybridization and peptide immunocytochemistry demonstrated that vgf mRNA was expressed in most vasopressin- and neurophysin-immunoreactive neurons in the dorsomedial part and in vasoactive intestinal peptide (VIP)- and peptide histidine isoleucine amide (PHI)-immunoreactive neurons in the ventrolateral part. These findings suggest that vgf is a highly expressed gene in both vasopressin/neurophysin neurons and VIP/PHI neurons which were speculated to be involved in the generation and entrainment of circadian rhythm.