Expandable metallic stent endoprosthesis for preoperative "bridge to surgery" treatment of obstructive colorectal cancer has been broadly, clinically used with good short-term results. Stent insertion for malignant tumor, however, is controversial because of the increased risk of metastasis, invasion, and advancement of the cancer. We, first in the world, evaluated the long-term prognosis of expandable metallic stent insertion compared with emergency surgery without expandable metallic stent. Forty emergency operations (1986-1996) and 44 expandable metallic stent insertions (1993-2001) were retrospectively compared by history, duration, morbidity, and cumulative survival rate. There was no significant difference in age or lesion between the two groups. Postoperative complications were significantly less frequent in the expandable metallic stent group: wound infection was 14 vs. 2 percent; leakage following to anastomosis was 11 vs. 3 percent. Long-term prognosis did not significantly differ: three-year overall survival rate was 50 vs. 48 percent; five-year survival rate was 44 vs. 40 percent in the emergency operation and expandable metallic stent groups, respectively. Because preoperative expandable metallic stent insertion for obstructive colorectal cancer had good postoperative results and no disadvantages in long-term prognosis, this procedure should be used in preoperative treatments of obstructive colorectal cancer.

Colorectal cancer is the most common cancer in Japan. Approximately 10%-20% of the patients with colorectal cancer present with large bowel obstruction, and those who present with malignant colonic obstruction (MCO) require urgent decompression because MCO can cause electrolytic fluid imbalance, colonic necrosis, bacterial translocation, and death. Placement of colonic stents (self-expandable metallic stents) for MCO is a major and standard endoscopic treatment that has been available since 2012 in Japan. This review presents the current conditions and future prospects of this procedure based on the literature. The current indication of colonic stent placement is malignant colorectal stenosis. One of the purposes of using stents is palliative treatment; further, its advantages over emergency surgery with colostomy include avoidance of colostomy, relief of obstruction, shorter hospitalization, and better quality of life. In addition, stent placement can also be used as a bridge to surgery since the duration of the hospitalization is shorter and postoperative complications, colostomy rates, and mortality rates are lower with elective than with emergency surgery. Although recent studies have reported low complication rates related to colonic stents, complications may still occur, highlighting the importance of good preparation, adequate staffing, backup systems, and informed consent. The current major problem related to colonic stents is the lack of evidence on patients' long-term prognoses for bridge to surgery purposes, awaiting the results of ongoing clinical research.

(1) Background: Endoscopic colorectal stenting with high technical success and safety is essential in discussing the oncological outcomes for the management of malignant colorectal obstruction. Mechanical properties of self-expandable metal stents are usually considered to affect clinical outcomes. (2) Methods: A multicenter, prospective study was conducted in Japan. A self-expandable metal stent with low axial force was inserted endoscopically. The primary endpoint was clinical success, defined as the resolution of symptoms and radiological findings within 24 h. Secondary endpoints were technical success and adverse events. Short-term outcomes of 7 days were evaluated in this study. (3) Results: Two hundred and five consecutive patients were enrolled. Three patients were excluded, and the remaining 202 patients were evaluated. The technical and clinical success rates were 97.5% and 96.0%, respectively. Major stent-related adverse events included stent migration (1.0%), insufficient stent expansion (0.5%), and stent occlusion (0.5%). No colonic perforation was observed. There were two fatal cases (1%) which were not related to stent placement. (4) Conclusions: The placement of self-expandable metal stents with low axial force is safe with no perforation and showed high technical and clinical success rates in short-term outcomes for the management of malignant colorectal obstruction.

Background/Aim: To compare intra-abdominal remnant bacterium between laparotomy and laparoscopic colorectal surgery. Methods: 72 patients with nonobstructive colorectal cancer were divided into two groups: laparotomy (47 cases) and laparoscopic surgery (25 cases). At the beginning of the operation just after the laparotomy incision was made or the trocars were inserted, 10 ml saline was irrigated into the Douglas pouch and collected through Nelaton’s catheter. Just before closing the wound, 10 ml saline was collected in the same way as the initial lavage in both groups. The collected saline as a specimen was determined to obtain the number of surviving bacterium. Results: No growth of bacteria was observed at the beginning of both operations. The remnant bacterial detection rates from the lavage fluid collected just before closing the wound were 23 of 47 cases (49%) in the laparotomy group and 7 of 25 cases (28%) in the laparoscopic surgery group; higher detection was observed in the laparotomy group. The mean bacteria cell counts after lavage were 4.6 × 10⁶ CFU/ml of aerobic bacteria and 1.9 × 10³ CFU/ml of anaerobic bacteria in the laparotomy group and 1.8 × 10⁴ CFU/ml of aerobic bacteria and 1.6 × 10² CFU/ml in the laparoscopic surgery group: the laparotomy group demonstrated an apparently higher number of remnant bacterium. Conclusions: In colorectal resections, laparoscopic surgery demonstrated a lower incidence of intra-abdominal contamination than laparotomy.

Evidence of the efficacy and safety of colorectal stent placement for palliation remains insufficient. This single-arm, prospective, multicenter study with a WallFlex enteral colonic stent included 200 consecutive patients with malignant large bowl obstruction in the palliation cohort. The technical and clinical success, as well as stent patency and complications as short-term (≤7 days) and long-term (>7 days) outcomes, of high axial force self-expandable metal stent (SEMS) placement was evaluated. The technical and clinical success rates were 98.5% and 94.5%, respectively. Non-recurrent colorectal obstruction at 1 year was 63.9%, and 71.2% of the patients remained free of recurrent colorectal obstruction until death or the last follow-up. Fifty-six patients (28.0%) received chemotherapy, and five patients were administered bevacizumab after stent placement. The overall complication rate was 47%, including four (2.0%) early-onset and ten (5.0%) late-onset perforations, mostly due to stent-edge injury. Only the use of a long SEMS was a risk factor for perforation. In conclusion, endoscopic colorectal stenting using high axial force SEMS is an effective and safe procedure for palliation in patients with malignant colorectal obstruction. However, care should be taken to avoid perforation at the stent edge when using a long SEMS.