Grasping forceps-assisted endoscopic mucosal resection of early gastric cancer with a novel 2-channel prelooped hood

Use of prototype two-channel endoscope with elevator enables larger lift-and-snare endoscopic mucosal resection in a porcine model

Background: Flat and depressed lesions are becoming increasingly recognized in the esophagus, stomach, and colon. Various techniques have been described for endoscopic mucosal resection (EMR) of these lesions.

Aims: To evaluate the efficacy of lift-grasp-cut EMR using a prototype dual-channel forward-viewing endoscope with an instrument elevator in one accessory channel (dual-channel elevator scope) as compared to standard dual-channel endoscopes.

Methods: EMR was performed using a lift-grasp-cut technique on normal flat rectosigmoid or gastric mucosa in live porcine models after submucosal injection of 4 mL of saline using a dual-channel elevator scope or a standard dual-channel endoscope. With the dual-channel elevator scope, the elevator was used to attain further lifting of the mucosa. The primary endpoint was size of the EMR specimen and the secondary endpoint was number of complications.

Results: Twelve experiments were performed (six gastric and six colonic). Mean specimen diameter was 2.27 cm with the dual-channel elevator scope and 1.34 cm with the dual-channel endoscope (P = 0.018). Two colonic perforations occurred with the dual-channel endoscope, vs no complications with the dual-channel elevator scope.

Conclusions: The increased lift of the mucosal epithelium, through use of the dual-channel elevator scope, allows for larger EMR when using a lift-grasp-cut technique. Noting the thin nature of the porcine colonic wall, use of the elevator may also make this technique safer.

Development of a novel endoscopic manipulation system: The Endoscopic operation robot

AIM: To develop and evaluate the endoscopic operation robot (EOR). The EOR is a robot system designed specifically for remote manipulation of the scope during gastrointestinal endoscopy by a seated endoscopist.

METHODS: Total colonoscopy examinations using a colonoscopy training model were performed compared conventional insertion by manual manipulation and remote-controlled insertion, using the EOR. The author investigated the time taken for each of the 50 examinations.

RESULTS: The median insertion time (in minutes) for each 10 examinations (EOR vs manual manipulation) was 73.70 ± 25.37 vs 3.77 ± 1.34 in the first group, 38.40 ± 6.24 vs 3.40 ± 0.97 in the second group, 27.6 ± 4.01 vs 2.70 ± 0.95 in the third group, 23.8 ± 3.65 vs 3.10 ± 0.88 in the fourth group, and 22.9 ± 5.02 vs 2.60 ± 1.08 in the fifth group.

CONCLUSION: The study suggested the possibility of the clinical application of the EOR.

Endoscopic mucosal resection and endoscopic submucosal dissection for early gastric cancer: Current and original devices

Compared with endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR) is easier to perform and requires less time for treatment. However, EMR has been replaced by ESD, because achieving en bloc resection of specimens > 20 mm in diameter is difficult with EMR. The technique of ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precise histological diagnosis and can also reduce the rate of recurrence, but has a high level of technical difficulty, and is consequently associated with a high rate of complications, a need for advanced endoscopic techniques, and a lengthy procedure time. To overcome disadvantages in both EMR and ESD, various advances have been made in submucosal injections, knives, other accessories, and in electrocoagulation systems.

Reliability of endoscopic esophageal mucosectomy using TxHood, a multipurpose treatment hood

Endoscopic mucosectomy, comprising both endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), is a minimally invasive treatment for patients with early esophageal carcinoma. The use of ESD is appropriate for mucosal lesions of any size. However, ESD techniques are relatively difficult and can lead to serious complications such as perforation and massive bleeding, which have been reported more frequently after ESD than after EMR. This study describes a novel technique for ESD using a newly designed multipurpose treatment hood (TxHood) as well as basic experiments to ensure its safety. The TxHood includes various therapeutic tools such as an electric needleknife, a snare wire, and an injection needle, and the lines can be selected freely before insertion of an enodoscope covered by a TxHood. The main techniques for ESD are endoscopic submucosal saline injections on demand through a working channel of the endoscope or TxHood and a cut or swing cut with a needleknife attached to the TxHood. Moreover, the target area can be grasped with a grasping forceps through a working channel of the endoscope to obtain effective countertraction. In these experiments, an electric needleknife set parallel to the shaft of the endoscope offered safety and ease of handling for the dissecting procedures. Altogether, 16 resections of mucosa with an average size of 3.5 x 2.5 cm (range, 2 x 2 to 7 x 4 cm) were performed. The average time required for each targeted endoscopic resection area was about 15 min. No perforations or instances of uncontrollable bleeding occurred. In conclusion, this basic study demonstrates that the new ESD technique with the TxHood provides a useful treatment for early esophageal carcinoma and may be applicable for all mucosal or submucosal tumors in the gastrointestinal tract.

Novel techniques and instrumentation for EMR, ESD, and full-thickness endoscopic luminal resection

Endoscopic intervention is evolving into an established therapeutic alternative for small superficial lesions, and an eventual application for en bloc resection of large lesions, deeper layers, and a reliable access to lesions outside of the gastrointestinal wall. Although further developmental and clinical evaluation is necessary, we believe endoscopic resection by the submucosal route and by full-thickness approaches will replace standard surgical procedures in the next several years.