Novel technique of endoscopic submucosal dissection by using external forceps for early rectal cancer (with videos).

BACKGROUND: Endoscopic submucosal dissection (ESD) is more difficult for rectal cancer than for gastric cancer. OBJECTIVE: To evaluate the feasibility and safety of an ESD procedure by using external forceps for early rectal cancer. DESIGN: A case series. SETTING: A tertiary medical center. PATIENTS: Thirteen patients with early-stage rectal cancer were enrolled. Twelve of the 13 lesions were granular-type laterally spreading tumors and 1 was a protruding tumor. INTERVENTIONS: After circumferential incision around the lesion with a dual-knife or a flex-knife, bendable external forceps were introduced with the help of grasping forceps inserted through the accessory channel and anchored at the anal margin of the lesion. After the forceps were bent, they were locked. With gentle anal traction and bending applied with the forceps, the lesion was elevated, the submucosal layer was opened, and the submucosal layer was dissected from the grasped side, facilitating dissection of the submucosal layer under direct vision. MAIN OUTCOME MEASUREMENTS: Technical success, complication rates. RESULTS: The mean lesion size was 33.0 mm (range 20-80 mm), and the mean operating time was 60 minutes (range 20-150 minutes). All lesions could be resected en bloc with tumor-free margins. Major bleeding after ESD occurred in only 1 patient (7.7%), who did not require blood transfusion. Perforation did not occur in any patient. LIMITATIONS: Single-center experience, small number of patients. CONCLUSION: This ESD procedure using external forceps for early-stage rectal cancers is feasible and safe.

Transmural pressure loading enhances gastric mucosal cell proliferation.

AIM: Although increased intraluminal pressure in the stomach due to gastric outlet obstruction or functional gastric motor dysfunction, including gastroparesis, may affect gastric mucosal integrity, the direct effect of mechanical pressure on gastric mucosal cells has not yet been fully investigated. The aims of this study were to determine whether exposure to transmural pressure would affect the proliferation of gastric mucosal cells and to elucidate the intracellular signaling pathways involved. METHODS: Cellular proliferation and DNA synthesis were evaluated in rat gastric epithelial cells exposed to high transmural pressures. The levels of activation of 3 MAP kinases, ERK, JNK, and p38, were assessed, and the induction of immediate early gene expression was examined. The activation of nuclear factor activator protein-1 (AP-1) was evaluated by an electrophoretic mobility shift assay. RESULTS: Exposure to high transmural pressure significantly increased DNA synthesis within 24 h, with the most marked increase observed after exposure to a pressure of 80 mmHg, and this increase was inhibited by the MEK1 inhibitor PD98059. Early activation of ERK kinase, but not of JNK or p38 kinase, was detected after pressure loading. Early induction of the c-fos and c-myc genes and activation of the AP-1 transcription factor were also demonstrated within 3 h of exposure to 80 mmHg of pressure. CONCLUSION: Gastric mucosal cell proliferation induced by exposure to high transmural pressure may be related to early activation of ERK, the induction of c-fos and c-myc, and the activation of AP-1.

Clinical results of observation of the upper gastrointestinal tract by transgastrostomic endoscopy using an ultrathin endoscope.

BACKGROUND AND AIM: Esophagogastroduodenoscopy through the oral cavity of patients who have undergone percutaneous endoscopic gastrostomy (PEG) causes some distress and puts these patients at risk of aspiration pneumonia. The aim of this study was to evaluate results for the upper gastrointestinal tract by transgastrostomic endoscopy using an ultrathin endoscope. METHODS: The study subjects were 43 patients, who underwent exchange of a PEG button or tube, 20-French or more in diameter. After PEG buttons or tubes were extracted from the gastrostomy tract, an ultrathin endoscope was inserted through the gastrostomy tract. The stomach and the duodenal bulb were observed and the esophagus was observed in retrograde passage. A new PEG button or tube was then inserted. The rate of successful insertion into the esophagus and duodenal bulb, the observation of the gastrostomy site in retroversion in the stomach, and the endoscopic findings were analyzed. RESULTS: Ninety-nine examinations were carried out. The esophagus could be observed in 95 (96.0%), the duodenum in 92 (92.9%) and the gastrostomy site in the stomach in all. Gastric polyps were detected in four patients, gastric erosions in two, reflux esophagitis in two, polypoid lesion at the gastrostomy tract in two, gastric ulcer scar in one, duodenal ulcer scar in one, early gastric cancer in one and recurrent esophageal cancer in one. Neither discomfort nor complications occurred during transgastrostomic endoscopy. CONCLUSIONS: Observation of the upper gastrointestinal tract by transgastrostomic endoscopy using an ultrathin endoscope during a gastrostomy button or tube replacement may be useful and safe.

Clinical results of endoscopic hemostasis using a short transparent hood and short hemoclips for non-variceal upper gastrointestinal bleeding.

AIM: Endoscopic hemostasis using hemoclips is useful, but there are technical difficulties because the angle of the approach is tangential. A transparent hood facilitates the observation and treatment of these lesions, and a shorter hood provides a wider visible field. Endoscopic hemoclipping of hard lesions with hemoclips of the conventional size does not reliably result in sustained hemostasis because the clips slip. Short clips, however, can be easily clamped on protruded visible vessels without slip. The aim of the present study was to evaluate the efficacy of endoscopic hemostasis with a short transparent hood and short clips. METHODS: Subjects were 198 patients with 214 lesions of non-variceal upper gastrointestinal bleeding at Keio University Hospital. We used a video endoscope with a short transparent hood attached to its distal tip and carried out hemostasis using short hemoclips. RESULTS: The short transparent hood provided a good visual field. If the lesions were in the tangential, the short hood made it possible to observe them in the frontal view and made clip hemostasis much easier. The short clip could be securely clamped against protruded visible vessels. Of 214 lesion, 211 (98.6%) had temporal hemostasis. Rebleeding occurred in 13 of 211 lesions (6.2%), and 205 of 214 lesions (95.8%) had permanent hemostasis. Nine cases were endoscopically difficult. CONCLUSION: Endoscopic hemostasis with a short transparent hood and short clips is useful for non-variceal upper gastrointestinal bleeding.

Nuclear factor-kappaB and TNF-alpha mediate gastric ulceration induced by phorbol myristate acetate.

Phorbol esters induce inflammation in rodents by activating protein kinase C. We determined whether nuclear factor-kappaB (NF-kappaB) and tumor necrosis factor-alpha (TNF-alpha) play role in the formation of gastric ulcer induced by phorbol-12-myristate-13-alphacetate (PMA) in rats. Subserosally injected PMA dose-dependently induced gastric mucosal ulcer. Activation of NF-kappaB in the gastric mucosa corresponding to the PMA injection sites was observed before the ulcers became obvious as assessed by an in situ fluorescence DNA binding assay and electrophoretic mobility shift assay. The NF-kappaB activation and subsequent ulcer formation were significantly inhibited by injection of pyrrolidine dithiocarbamate, proteasome inhibitor (MG132), or NF-kappaB decoy. Antibody against TNF-alpha significantly inhibited ulcer formation without attenuating NF-kappaB activation. These results suggest that both NF-kappaB activation followed by TNF-alpha release contribute to tissue damage in PMA-induced gastric ulcer formation.