Hydrogen peroxide-assisted endoscopic necrosectomy of pancreatic walled-off necrosis: a systematic review and meta-analysis.

BACKGROUND AND AIMS: Use of hydrogen peroxide (H2O2) has been reported in direct endoscopic necrosectomy (DEN) of pancreatic walled-off necrosis (WON). The aim of this meta-analysis was to study the pooled clinical outcomes of H2O2-assisted DEN of pancreatic WON. METHODS: We conducted a comprehensive search of several databases (inception to July 2021) to identify studies reporting on the use of H2O2 in DEN of WON. A random-effects model was used to calculate pooled rates and I2 values, and 95% prediction intervals were used to assess heterogeneity. The outcomes studied were technical success, clinical success, and adverse events in H2O2-assisted DEN of pancreatic WON. RESULTS: In 7 analyzed studies, 186 patients underwent H2O2-assisted DEN of WON. The pooled rate of technical success was 95.8% (95% confidence interval [CI], 88.5-98.5), clinical success was 91.6% (95% CI, 86.1-95), and cumulative rate of overall adverse events was 19.3% (95% CI, 7.6-41). The pooled rate of bleeding was 7.9% (95% CI, 2.4-22.7), stent migration was 11.3% (95% CI, 4.9-23.9), perforation 5.4% (95% CI, 1.7-15.7), infection 5.7% (95% CI, 2-15.1), and pulmonary adverse event 2.9% (95% CI, 1.3-6.1). Mean treatment sessions ranged from 2 to 5. CONCLUSIONS: H2O2-assisted DEN of WON demonstrated excellent clinical outcomes, with minimal heterogeneity. No adverse events attributable to H2O2 were reported. Future controlled studies are warranted comparing the clinical outcomes with and without H2O2 before H2O2 use can be established in DEN of pancreatic WON.

Clinical and Molecular Features of Post-Colonoscopy Colorectal Cancers.

BACKGROUND & AIMS: Post-colonoscopy colorectal cancers (PCCRCs) may arise from missed lesions or due to molecular features of tumors that allow them to grow rapidly. We aimed to compare clinical, pathology, and molecular features of PCCRCs (those detected within 6-60 months of colonoscopy) and detected CRCs (those detected within 6 months of a colonoscopy). METHODS: Within a population-based cross-sectional study of incident CRC cases in Utah (from 1995 through 2009), we identified PCCRCs (those cancers that developed within 5 years of a colonoscopy) and matched the patients by age, sex, and hospital site to patients with detected CRC. Archived specimens were retrieved and tested for microsatellite instability (MSI), CpG island methylation, and mutations in KRAS and BRAF. There were 2659 cases of CRC diagnosed within the study window; 6% of these (n = 159) were defined as PCCRCs; 84 of these cases had tissue available and were matched to 84 subjects with detected CRC. RESULTS: Higher proportions of PCCRCs than detected CRCs formed in the proximal colon (64% vs 44%; P = .016) and were of an early stage (86% vs 69%; P = .040). MSI was observed in 32% of PCCRCs compared with 13% of detected CRCs (P = .005). The other molecular features were found in similar proportions of PCCRCs and detected CRCs. In a multivariable logistic regression, MSI (odds ratio, 4.20; 95% CI, 1.58-11.14) was associated with PCCRC. There was no difference in 5-year survival between patients with PCCRCs vs detected CRCs. CONCLUSION: In this population-based cross-sectional study of incident CRC cases in Utah, we found PCCRCs to be more likely to arise in the proximal colon and demonstrate MSI, so PCCRCs and detected CRC appear to have different features or processes of tumorigenesis. Additional studies are needed to determine if post-colonoscopy cancers arise through a specific genetic pathway.

Gastrointestinal endoscopic ultrasonography.

Although conventional endoscopy provides excellent visualization of gastrointestinal mucosa, it provides little information about intramural or nearby extramural lesions. The imaging of intraabdominal structures by conventional transabdominal ultrasound is degraded by ultrasound energy attenuation with distance. The provision of an ultrasound probe on a flexible gastrointestinal endoscope, to form an echoendoscope, provides excellent imaging of the gastrointestinal wall and of adjacent extramural structures. During the last two decades, endoscopic ultrasound, using an echoendoscope, has revolutionized the diagnosis and treatment of gastrointestinal diseases that affect the submucosa, deep bowel wall, and adjacent extramural structures. This article reviews the role of endoscopic ultrasound in the diagnosis and treatment of gastrointestinal disease, including standard and promising new applications, as well as standard and emerging new technology.