The efficacy and safety of underwater endoscopic mucosal resection for ≥10-mm colorectal polyps: systematic review and meta-analysis

BACKGROUND

Underwater endoscopic mucosal resection (UEMR) is a promising strategy for nonpedunculated colorectal polyp removal. However, the efficacy and safety of the technique for the treatment of ≥ 10-mm colorectal polyps remain unclear. We aimed to comprehensively assess the efficacy and safety of UEMR for polyps sized 10-19 mm and ≥ 20 mm.

METHODS

PubMed, EMBASE, and the Cochrane Library databases were searched for relevant articles from January 2012 to November 2019. Primary outcomes were the rates of adverse events and residual polyps. Secondary outcomes were the complete resection, en bloc resection, and R0 resection rates.

RESULTS

18 articles including 1142 polyps from 1093 patients met our inclusion criteria. The overall adverse event and residual polyp rates were slightly lower for UEMR when removing colorectal polyps of 10-19 mm vs. ≥ 20 mm (3.5 % vs. 4.3 % and 1.2 % vs. 2.6 %, respectively). The UEMR-related complete resection rate was slightly higher for colorectal polyps of 10-19 mm vs. ≥ 20 mm (97.9 % vs. 92.0 %). However, the en bloc and R0 resection rates were dramatically higher for UEMR removal of polyps of 10-19 mm vs. ≥ 20 mm (83.4 % vs. 36.1 % and 73.0 % vs. 40.0 %, respectively). In addition, univariate meta-regression revealed that polyp size was an independent predictor for complete resection rate (P = 0.03) and en bloc resection (P = 0.01).

CONCLUSIONS

UEMR was an effective and safe technique for the removal of ≥ 10-mm nonpedunculated colorectal polyps. However, UEMR exhibited low en bloc and R0 resection rates for the treatment of ≥ 20-mm polyps.

Efficacy of low-dose versus high-dose simethicone with polyethylene glycol for bowel preparation: A prospective randomized controlled trial

BACKGROUND AND AIM

Additional simethicone (SIM) can improve adequate bowel preparation and adenoma detection rate (ADR). However, there is no consensus on the optimal dose of SIM. In this study, we compared the adequate bowel preparation rate with supplementation of split-dose 2 L polyethylene glycol (PEG) with low-dose SIM (200 mg) versus high-dose SIM (1200 mg).

METHODS

This was a prospective, randomized, observer-blinded trial involving consecutive subjects undergoing colonoscopy. The primary outcome was adequate bowel preparation as assessed by Boston Bowel Preparation Scale (BBPS) score.

RESULTS

Four hundred subjects were randomly allocated to low-dose SIM or high-dose SIM group. Baseline characteristics were comparable in the two groups (P > 0.05). No significant between-group differences were observed with respect to total bubble scale (BS) (8.49 ± 1.00 vs 8.39 ± 1.10, P = 0.07), total BBPS score (8.70 ± 0.81 vs 8.29 ± 1.18, P = 0.98), ADR (33.68% vs 31.79%, P = 0.69) or withdrawal time (13 [range, 10-16] min vs 13 [10-15] min, P = 0.96). The intubation time in low-dose SIM group was significantly shorter than that in high-dose SIM group (8 (4-16) min vs 10 [6-17] min, P = 0.04). In addition, BS scores as well as diminutive ADR in right colon were superior in the low-dose SIM group (2.68 ± 0.59 vs 2.52 ± 0.73, P = 0.03 and 54.29% vs 30.30%, P = 0.046, respectively).

CONCLUSION

Addition of low-dose SIM to split-dose 2 L PEG was as effective as addition of high-dose SIM with respect to adequate bowel preparation, ADR and patient tolerance. However, low-dose SIM was superior with respect to intubation time, right colon BS scores, right colon diminutive ADR and cost savings.

Effect and safety of mark-guided vs standard peroral endoscopic myotomy: A retrospective case control study

BACKGROUND

Peroral endoscopic myotomy (POEM) is a promising therapeutic modality for esophageal achalasia worldwide. However, clinical failure and adverse events of POEM have still been concerned.

AIM

To compare the efficacy and safety of a novel mark-guided POEM with standard POEM.

METHODS

A total of 133 patients with esophageal achalasia who underwent POEM from May 2013 to May 2019 were enrolled in this retrospective study. Of the 133 patients, there were 64 patients in the mark-guided POEM group and 69 patients in the standard POEM group. The clinical success, procedural duration and adverse events were compared between the two groups at 3 mo, 12 mo and 24 mo postoperatively.

RESULTS

Characteristic baseline was similar in the mark-guided POEM group and standard POEM group. The clinical success was comparable between the two groups, ranging from 92% to 98%, at 3 mo, 12 mo and 24 mo postoperatively (all P > 0.5). Eckart score, Gastroesophageal Reflux Disease Questionnaire score and SF-36 score were not different between the two groups after treatment (all P > 0.05). No severe adverse events occurred in the two groups. However, mark-guided POEM required shorter procedural duration, and less use of proton pump inhibitors and lower incidence of reflux symptoms than the standard POEM (all P < 0.001).

CONCLUSION

Mark-guided POEM and standard POEM were both effective and safe for the treatment of esophageal achalasia. However, the mark-guided POEM was characterized by shorter procedural duration, less use of proton pump inhibitors and lower incidence of reflux symptoms.

Bifidobacteria Expressing Tumstatin Protein for Antitumor Therapy in Tumor-Bearing Mice

Tumstatin (Tum) is a powerful angiostatin that inhibits proliferation and induces apoptosis of tumorous vascular endothelial cells. A nonpathogenic and anaerobic bacterium, Bifidobacterium longum (BL), selectively localizes to and proliferates in the hypoxia location within solid tumor. The aims of this study were to develop a novel delivery system for Tum using engineered Bifidobacterium and to investigate the inhibitory effect of Tum on tumor in mice. A vector that enabled the expression of Tum under the control of the pBBADs promoter of BL was constructed and transformed into BL NCC2705 by electroporation. The mouse colon carcinoma cells CT26 (1 × 10(7)/mL) were subcutaneously inserted in the left armpit of BALB/c mice. The tumor-bearing mice were treated with Tum-transformed BL, and green fluorescent protein (GFP)-transformed BL was used as a negative control. The microvessel density (MVD) in the transplanted tumor was determined, and terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling was used to detect apoptosis of vascular endothelial cells in transplanted tumor. The in vitro expression of Tum was examined in BL after l-arabinose induction. Bifidobacterium longum with pBBAD-Tum (BL-Tum) showed significant antitumor effect in tumor-bearing mice. The weight, volume, growth, and MVD, as well as the percentage of apoptotic vascular endothelial cells of transplanted tumors in the tumor-bearing mice treated with Tum-transformed BL were all significantly lower than those in the GFP negative control group. Intragastric administration, injection in tumor and vena caudalis injection of Tum-transformed BL exerted marked antitumor effects in tumor-bearing mice. This is the first demonstration of the utilization of Tum-transformed BL as a specific gene delivery system for treating tumor.

Treatment of mice with dextran sulfate sodium-induced colitis with human interleukin 10 secreted by transformed Bifidobacterium longum

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) the etiology of which has not yet been fully clarified. Cytokine interleukin-10 (IL-10) plays a central role in downregulating inflammatory cascade in UC and is likely a candidate for therapeutic intervention. However, its intravenous administration is costly and inconvenient. Therefore, we established a novel IL-10 delivery system by transforming a hIL-10-containing plasmid into B. longum (BL-hIL-10) and investigated its effects on 5% dextran sulfate sodium (DSS)-induced ulcerative colitis in mice and the possible underlying mechanism. Our results show that (1) hIL-10 was expressed and secreted into the culture supernatant of BL-hIL-10 after L-arabinose induction in vitro as examined by Western blot, enzyme-linked immunosorbent assay (ELISA) and RT-PCR; (2) addition of BL-hIL-10 culture supernatant had no cytotoxic effect and morphological alteration, but significantly inhibited the enhancement of proinflammatory cytokines by lipopolysaccharide (LPS) in THP-1 cells; (3) oral administration of BL-hIL-10 alleviated colitis syndrome of the model mice, attenuated colitis-activated NF-κB pathway measured by DNA-binding assay and colitis-elevated expression of proinflammatory cytokines examined with CCK cytotoxic kits, and upregulated CD4+CD25+Foxp3+ Treg in blood and mesenteric lymph nodes measured by flow cytometry. In conclusion, BL-hIL-10 as a novel oral hIL-10 delivery system has been successfully established and oral administration of BL-hIL-10 alleviated inflammatory damage of colonic tissue in the model mice by blocking the colitis-activated NF-κB pathway and upregulating CD4+CD25+Foxp3+ Treg in blood and mesenteric lymph nodes in mice.