Risk factors for post-polypectomy bleeding; a retrospective case-control study of a high-volume colonoscopy center

Background and aim Post-polypectomy bleeding (PPB) remains an uncommon although serious complication of colonoscopy. The aim of this study is to determine the PPB-prevalence in a secondary care hospital and its associated risk factors. Patients and methods We collected data from 581 patients, with the removal of 1593 polyps between August 2017 and August 2019. A univariate binary logistic regression analysis was conducted retrospectively. Results PPB occurred in only 10 cases, representing 1.7% of patients: immediate in 1.2% and delayed in 0.5%. The number of removed polyps per patient [4.5 (SD 2.59) for hemorrhagic vs. 2.74 (SD 1.98) for non-hemorrhagic group] and the propofol dose [232 mg (SD 93.07) for hemorrhagic vs. 133 mg (SD 57.28) for non-hemorrhagic group] were relevant patient-related risk factors. The polyp-based analysis showed the polyp size [18.4 mm (SD 10.44) for hemorrhagic vs. 4.42 mm (SD 4.29) for non-hemorrhagic group], the morphology [wide-based: OR 24.83 (95 % CI 2.76 – 223.44), pedunculated: OR 56.67 (95 % CI 5.03 – 638.29)], the location at ileocecal valve [OR 20.48, 95 % CI 1.81 – 231.97)], and the polypectomy method [hot snare piecemeal with epinephrine injection: OR 75.38 (95 % CI 7.67 – 741.21)] as significant risk factors for PPB, too. Conclusions The low rate of PPB confirms the safety of the procedure in non-tertiary, high-volume colonoscopy centers. The number of polyps removed per patient, the polyp size, morphology and location, as well as the sedation dose and the method of polypectomy were shown as relevant risk factors.

P-O03 The Management of Gallbladder Polyps at a Single Trust: Are we compliant with European Guidelines?

Background Gallbladder polyps affect approximately 5% of the global population, with rates highest in those of Indian descent. 10% of polyps will have malignant potential based on their size or rapid growth rate, which are associated with a poor 5-year survival once advanced of less than 25%. As gallbladder polyps are common but gallbladder cancer is rare, it is a diagnostic challenge to determine which polyps are likely to be malignant. Adherence to guidelines regarding radiological follow up and definitive treatment, in the form of a cholecystectomy, is therefore vital. Methods Retrospective data collection and analysis was completed for all patients who had a biliary ultrasound between December 2013 and December 2016 to enable 5-year follow up, and a snapshot of 47 patients selected at random. Patients having a gallbladder “polyp” documented on their scan report were eligible for inclusion and adherence to European Society of Gastrointestinal and Abdominal Radiology (ESGAR) guidelines was assessed. Results Within the cohort there was a mean age of 56 years, with a male:female ratio of 17:30. All patients included were Caucasian, with 41 reporting “biliary symptoms” as the indication for the primary ultrasound. 26 patients were not followed up in adherence to guidelines, with 50% due to the sonographer reporting follow-up was not indicated on initial scan, 5 having unchanged polyp size and 2 discharged by the responsible consultant. Of the 21 who were followed up according to guidelines, 20 had a cholecystectomy within 5years, with none of these patients having cancer detected on histology. Conclusions Over 50% of patients within our cohort were not followed up according to the ESGAR guidelines. Although no patients in the study were found to have malignant polyps, the sample size is relatively small and limited to low-risk groups. We aim to expand this audit both locally and regionally, raise awareness of the importance of surveillance across the multi-disciplinary team, and produce local guidance for the outpatient setting.

P-BN31 Surveillance for Gallbladder polyps at a NHS District General Hospital – a retrospective analysis

Background Gallbladder polyps are encountered in 5% of ultrasound scans and continue to remain a dilemma in terms of management. Very few polyps progress to cancer. However, most cancerous polyps are usually found at an advanced stage. It is therefore important to identify the premalignant polyps. There is a lack of national consensus in UK for surveillance of gallbladder polyps. Many trusts in the UK either adopt the European guidelines or formulate local protocols. We aim to present our findings based on our local surveillance policy existent during the study period with a view to recommending new local guidelines. Methods A search from our radiology database being coded to gallbladder polyp identified patients. We identified 431 patients from 2017 – 2019 who had a total of 1014 scans. The data was collected from local hospital IT databases in terms of variables such as number of scans, polyp size, number of polyps, progression to surgery or discharge from surveillance and histology. The data was analysed on excel platform. Results Patient demographics revealed an incidence of 54% in females (males 46%) with an average age of 59.7 years. Pain was the dominant symptom prompting the first scan (48%). An average of 2.3 scans were performed per patient. 45% of the polyps were less than 5mm. Overall, 22% polyps demonstrated interval growth. Only 15% of polyps less than 5mm demonstrated interval growth and none required cholecystectomy. 6% patients proceeded to surgery mainly for symptoms (46%) compared to polyp progression (1.5%). No malignancy was identified in this study. 43% of patients with polyp diagnosis in primary care had no identified surveillance plan. Conclusions Our study demonstrates a low incidence of polyp progression. We would recommend stopping annual surveillance after 2 years from the index scan for multiple small (<5mm) polyps with little or no progression but continue with annual surveillance for polyps greater than 5mm. We would recommend reserving cholecystectomy for symptomatic polyps and polyps greater than 10mm. There is wide variation in surveillance practice particularly in primary care. We would recommend sharing the guideline widely with primary care for optimal surveillance.

Monocyte Chemotactic Proteins (MCP) in Colorectal Adenomas Are Differently Expressed at the Transcriptional and Protein Levels: Implications for Colorectal Cancer Prevention

The expression of monocyte chemotactic proteins (MCPs) in colorectal polyps and their suitability as targets for chemoprevention is unknown, although MCP expression and secretion can be modulated by non-steroidal inflammatory drugs. This study was designed to determine the expression patterns of MCP-1/CCL2, MCP-2/CCL8, and MCP-3/CCL7 at the protein (immunohistochemistry; n = 62) and transcriptional levels (RTqPCR; n = 173) in colorectal polyps with reference to the polyp malignancy potential. All chemokines were significantly upregulated in polyps at the protein level but downregulated at the transcriptional level by 1.4-(CCL2), 1.7-(CCL7), and 2.3-fold (CCL8). There was an inverse relation between the immunoreactivity toward chemokine proteins and the number of corresponding transcripts in polyps (CCL2 and CCL7) or in normal mucosa (CCL8). The downregulation of chemokine transcripts correlated with the presence of multiple polyps (CCL2 and CCL8), a larger polyp size (CCL2, CCL7, and CCL8), predominant villous growth patterns (CCL2, CCL7 and CCL8), and high-grade dysplasia (CCL2 and CCL8). In conclusion, MCP-1/CCL2, MCP-2/CCL8, and MCP-3/CCL7 chemokines are counter-regulated at the protein and transcriptional levels. Chemokine-directed chemopreventive strategies should therefore directly neutralize MCP proteins or target molecular pathways contributing to their enhanced translation or reduced degradation, rather than aiming at CCL2, CCL7 or CCL8 expression.

“Smell improvement by anti-IgE and anti-IL 5 biologics in patients with CRSwNP and severe asthma– A real life study”

Background. Chronic rhinosinusitis with nasal polyps (CRSwNP), characterized by partial (hyposmia) or total (anosmia) loss of smell, is commonly associated with asthma and/or nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD), worsens disease severity and quality of life. The objective of this study was to determine whether, in real-life conditions, biological treatments prescribed for severe asthma can improve olfaction in patients with CRSwNP. A further objective was to compare smell improvement in N-ERD and non-N-ERD subgroups. Methods. A multicenter, non-interventional, retrospective, observational study was performed, including 206 patients with severe asthma undergoing biological treatment (omalizumab, mepolizumab, benralizumab, or reslizumab) with CRSwNP. Results. Improved olfaction was found after treatment with all monoclonal antibodies: omalizumab (35.8%), mepolizumab (35.4%), reslizumab (35.7%), and benralizumab (39.1%), with no differences between groups. Patients with atopy, greater use of short course systemic corticosteroids, and larger polyp size were more likely to experience improvement in smell. The proportion of patients experiencing smell improvement was similar between the N-ERD (37%) and non-N-ERD (35.7%) groups. Conclusions. This is the first study to compare real-life improvement in sense of smell among patients undergoing long-term treatment with omalizumab, mepolizumab, reslizumab, or benralizumab for severe asthma and associated CRSwNP. Approximately 4 out of 10 patients reported a subjective improvement in sense of smell (with non-significant differences between biologic drugs). No differences were found in smell improvement between the N-ERD and non-N-ERD group.

Endoscopic resection outcomes and predictors of failed en bloc endoscopic mucosal resection of colorectal polyps ≤ 20 mm among advanced endoscopy trainees

Background and study aims En bloc endoscopic mucosal resection (EMR) is preferred over piecemeal resection for polyps ≤ 20 mm. Data on colorectal EMR training are limited. We aimed to evaluate the en bloc EMR rate of polyps ≤ 20 mm among advanced endoscopy trainees and to identify predictors of failed en bloc EMR. Methods This was a multicenter prospective study evaluating trainee performance in EMR during advanced endoscopy fellowship. A logistic regression model was used to identify the number of procedures and lesion cut-off size associated with an en bloc EMR rate of ≥ 80 %. Multivariate analysis was performed to identify predictors of failed en bloc EMR. Results Six trainees from six centers performed 189 colorectal EMRs, of which 104 (55 %) were for polyps ≤ 20 mm. Of these, 57.7 % (60/104) were resected en bloc. Trainees with ≥ 30 EMRs (OR 6.80; 95 % CI: 2.80–16.50; P = 0.00001) and lesions ≤ 17 mm (OR 4.56;95 CI:1.23–16.88; P = 0.02) were more likely to be associated with an en bloc EMR rate of ≥ 80 %. Independent predictors of failed en bloc EMR on multivariate analysis included: larger polyp size (OR:6.83;95 % CI:2.55–18.4; P = 0.0001), right colon location (OR:7.15; 95 % CI:1.31–38.9; P = 0.02), increased procedural difficulty (OR 2.99; 95 % CI:1.13–7.91; P = 0.03), and having performed < 30 EMRs (OR: 4.87; 95 %CI: 1.05–22.61; P = 0.04). Conclusions In this pilot study, we demonstrated that a relatively low proportion of trainees achieved en bloc EMR for polyps ≤ 20 mm and identified procedure volume and lesion size thresholds for successful en bloc EMR and independent predictors for failed en bloc resection. These preliminary results support the need for future efforts to define EMR procedure competence thresholds during training.

Abundance and Characteristics of Microplastics in Seawater and Corals From Reef Region of Sanya Bay, China

Microplastics (MPs) contamination is widespread in the coral reef ecosystems leading to the exposure of both corals and other biotas. Knowledge gaps still exist concerning patterns in MPs abundance spatially. This work quantified the MPs abundance and characteristics in the seawater and corals in the Sanya Bay, Hainan Island. MPs abundance was detected in the seawater and coral samples ranging from 15.50 to 22.14 items L–1, and 0.01 to 3.60 items polyp–1, respectively. We found the predominant size and type of MPs in seawater and corals were smaller than 2 mm and fiber. Further analysis revealed that the characteristics of MPs in the corals were significantly different from those in the seawater environment, indicating that the MPs are selectively enriched in corals. Furthermore, the MPs particles ingested and retained in coral tissue may be related to the polyp size. This study shows that MPs are present in the whole coral reef region and the coral community structure would be potentially harmed by these contaminants.

Squamous Metaplasia in Colonic Tubulovillous Adenoma: A Three Case Series and review of literature

Introduction/Objective Although squamous metaplasia of colonic tubulovillous adenoma is a rare phenomenon, colorectal polyps can show focal squamous metaplasia. While the exact cause in unknown, it has been suggested that mechanical irritation, torsion and chronic inflammation may predispose to squamous metaplasia within large colonic polyps. Methods/Case Report We observed this finding in two men and one woman with colorectal polyps who underwent endoscopic mucosal resection in a three-week timeframe. In two cases the polyps were rectal, while in the third case, it was located in the descending colon. Polyp size ranged from 1-5 cm and were semi-pedunculated. Histologically, all three lesions were tubulovillous adenomas with focal high-grade dysplasia and multiple foci of squamous metaplasia characterized by cells with benign-appearing nuclei, eosinophilic cytoplasm, and solid growth pattern. Some metaplastic foci approached the muscularis mucosae, mimicking adenocarcinoma at low power magnification. Interestingly, these metaplastic foci were reactive against p16 immunohistochemical stain. Results (if a Case Study enter NA) NA Conclusion We present these three cases to add to the few previously reported. Pathologists should be aware of this finding to avoid the overdiagnosis of invasive carcinoma in the setting of nested and pseudo invasive squamous morules, especially in polyps with high grade dysplasia. In addition, squamous metaplasia could be a precursor lesion for colorectal squamous cell carcinoma.