6. CLEAN-NET

3. "The muscle layer is linearly sutured at approximately 5 mm intervals with the lesion

4. "A circumferential mucosubmucosal incision is performed from inside with electrocautery knife guided by the endoscope." These figures are excerpted from Goto's report.

He reported NEWS for three lesions (one anterior wall, one lesser curve and one posterior wall of the gastric body) using porcine stomach, and complete resection was achieved for all lesions safely and without perforation or air leakage. Nonexposure techniques such as NEWS and CLEAN-NET are adequate for SMT without ulceration as well as SMT with ulceration or even early gastric cancer. In his report, the maximal specimen size was 50 mm; however, there is a limit of removable tumor size. Because the resected tumor is removed through the pharynx by the endoscope, solid tumor such as GIST over 30 mm is thought to be difficult to retrieve.

inverted into the inside."

34 Gastric Cancer - An Update

A combination of laparoscopic endoscopic approaches to neoplasia with a nonexposure technique (CLEAN-NET) was first reported by Inoue et al. in [27]. This procedure also involves a nonexposure technique like NEWS, but with a difference. By preserving the continuity of the mucosa, the mucosa works as a barrier (a clean net), to prevent abdominal cavity contamination and seeding of tumor cells into the peritoneal cavity. The specimen is lifted from the peritoneal cavity, so it is retrieved laparoscopically. Inoue actively performs endoscopic and laparoscopic full-thickness resection for not only GISTs but also for early gastric cancer. The procedures are described below.

1. "Endoscopic markings are placed on the surrounding mucosa of the lesion with electrocautery knife."

2. "The mucosal layer is fixed onto the seromuscular layer using four stay sutures."

3. "By pulling four stitches upward with laparoscopic forceps, selective seromuscular dissection outside the four stiches is performed using a laparoscopic electrocautery knife."

The abovementioned procedure with nonexposure technique is advantageous for epithelial tumor and GIST with ulceration. CLEAN-NET also makes it possible to secure a sufficient margin around the tumor and to resect lymph nodes together with the tumor if it is located at either the lesser or greater curvature of the stomach. Because the CLEAN-NET procedure needs the process that the mucosal layer stretches without breaking apart, a large tumor is

Laparoscopic Endoscopic Cooperative Surgery: Current Status and Perspective

http://dx.doi.org/10.5772/intechopen.76983

37

This technique was reported by Abe et al. in [28]. The same procedure as LECS technique is applied; however, the endoscopist plays an important role in resecting the tumor. The endoscopic team starts full-thickness resection around the tumor, and after two-thirds of the resection is performed, the laparoscopic team finishes the full-thickness resection with laparoscopic

There are some limitations with LECS for removal of duodenal tumors. First, anatomical elements such as the pyloric ring, Vater's papilla and the third to fourth portion make it difficult to perform. Second, there are a few reports of lymph node metastasis from submucosal invading duodenal cancers or carcinoids, so partial resection is controversial. Small submucosal tumors, duodenal adenomas, or intramucosal carcinomas at duodenal bulb or the opposite side of the papilla are indications for LECS. The basic concept of gastric LECS also applies to duodenum LECS [4, 29]. The difficulty in mobilizing organs and closing the defected

LECS for colorectal tumors is not often used. We rarely experience GISTs in the colorectum, and in many cases the laparoscopist must achieve adequate mobilization which may be difficult in colorectal-LECS. Some researchers have reported the laparoscopy-assisted endoscopic resection (LAER) for colorectal tumors [30–32], and as the combined laparoscopic endoscopic resection (CLER). Fukunaga et al. reported LECS for laterally spreading colorectal tumors, which are difficult to resect by the ESD technique because of submucosal fibrosis or multiple surrounding diverticula [33] (Figures 18 and 19). He suggested several concerns about his technique: limitation for tumors located on the mesenteric side, strictures after surgery, and contamination of the abdominal cavity by bowel contents. He proposed several adjustments in his report. Indications for colorectal LECS are the same as for colorectal ESD. Tumors that would be difficult to resect endoscopically are good indications for both. Figures 18 and 19

7. Laparoscopy-assisted endoscopic full-thickness resection

thought to be difficult to resect.

7.1. LECS for duodenal tumors

walls needs to be advanced.

7.2. LECS for colorectal tumors

are excerpted from Fukunaga's report.

devices.

4. "A full-layer specimen is lifted by four stay sutures. This process allows a wider cancer-free margin around a full-thickness lesion."

5. "A full-layer resection using a mechanical stapler is performed and the resected tumor is removed from abdominal cavity side." These figures are excerpted from Inoue's report.

The abovementioned procedure with nonexposure technique is advantageous for epithelial tumor and GIST with ulceration. CLEAN-NET also makes it possible to secure a sufficient margin around the tumor and to resect lymph nodes together with the tumor if it is located at either the lesser or greater curvature of the stomach. Because the CLEAN-NET procedure needs the process that the mucosal layer stretches without breaking apart, a large tumor is thought to be difficult to resect.
