Citations

Many decellularized extracellular matrix-derived whole organs have been widely used in studies of tissue engineering and cancer models. However, decellularizing porcine esophagus to obtain decellularized esophageal matrix (DEM) for potential biomedical applications has not been widely investigated. In this study a modified decellularization protocol was employed to prepare a porcine esophageal DEM for the study of cancer cell growth. The cellular removal and retention of matrix components in the porcine DEM were fully characterized. The microstructure of the DEM was observed using scanning electronic microscopy. Human esophageal squamous cell carcinoma (ESCC) and human primary esophageal fibroblast cells (FBCs) were seeded in the DEM to observe their growth. Results show that the decellularization process did not cause significant loss of mechanical properties and that blood ducts and lymphatic vessels in the submucosa layer were also preserved. ESCC and FBCs grew on the DEM well and the matrix did not show any toxicity to cells. When FBS and ESCC were cocultured on the matrix, they secreted more periostin, a protein that supports cell adhesion on matrix. This study shows that the modified decellularization protocol can effectively remove the cell materials and maintain the microstructure of the porcine esophageal matrix, which has the potential application of studying cell growth and migration for esophageal cancer models.

Objective: The aim of this work is to formulate recommendations based on global expert consensus to guide the surgical community on the safe resumption of surgical and endoscopic activities. Background: The COVID-19 pandemic has caused marked disruptions in the delivery of surgical care worldwide. A thoughtful, structured approach to resuming surgical services is necessary as the impact of COVID-19 becomes better controlled. The Coronavirus Global Surgical Collaborative sought to formulate, through rigorous scientific methodology, consensus-based recommendations in collaboration with a multidisciplinary group of international experts and policymakers. Methods: Recommendations were developed following a Delphi process. Domain topics were formulated and subsequently subdivided into questions pertinent to different aspects of surgical care in the COVID-19 crisis. Forty-four experts from 15 countries across 4 continents drafted statements based on the specific questions. Anonymous Delphi voting on the statements was performed in 2 rounds, as well as in a telepresence meeting. Results: One hundred statements were formulated across 10 domains. The statements addressed terminology, impact on procedural services, patient/staff safety, managing a backlog of surgeries, methods to restart and sustain surgical services, education, and research. Eighty-three of the statements were approved during the first round of Delphi voting, and 11 during the second round. A final telepresence meeting and discussion yielded acceptance of 5 other statements. Conclusions: The Delphi process resulted in 99 recommendations. These consensus statements provide expert guidance, based on scientific methodology, for the safe resumption of surgical activities during the COVID-19 pandemic.

Objective Solid organ transplant (SOT) recipients have moderately increased risk of pancreatic adenocarcinoma (PAC). We evaluated the incidence and survival of PAC in 2 cohorts and aimed to identify potential risk factors. Methods This study performed a retrospective cohort analysis. Cohort A was extracted from the United Network of Organ Sharing data set and cohort B from SOT recipients evaluated at 3 Mayo Clinic transplant centers. The primary outcome was age-adjusted annual incidence of PAC. Descriptive statistics, hazard ratios, and survival rates were compared. Results Cohort A and cohort B included 617,042 and 29,472 SOT recipients, respectively. In cohort A, the annual incidence rate was 12.78 per 100,000 in kidney-pancreas, 13.34 in liver, and 21.87 in heart-lung transplant recipients. Receiving heart-lung transplant, 50 years or older, and history of cancer (in either recipient or donor) were independent factors associated with PAC. Fifty-two patients developed PAC in cohort B. Despite earlier diagnosis (21.15% with stage I–II), survival rates were similar to those reported for sporadic (non-SOT) patients. Conclusions We report demographic and clinical risk factors for PAC after SOT, many of which were present before transplant and are common to sporadic pancreatic cancer. Despite the diagnosis at earlier stages, PAC in SOT portends a very poor survival.

Abstract Background and study aim Delayed bleeding is a common adverse event following endoscopic mucosal resection (EMR) of large colorectal polyps. Prophylactic clip closure of the mucosal defect after EMR of nonpedunculated polyps larger than 20 mm reduces the incidence of severe delayed bleeding, especially in proximal polyps. This study aimed to evaluate factors associated with complete prophylactic clip closure of the mucosal defect after EMR of large polyps. Methods This is a post hoc analysis of the CLIP study (NCT01936948). All patients randomized to the clip group were included. Main outcome was complete clip closure of the mucosal resection defect. The defect was considered completely closed when no remaining mucosal defect was visible and clips were less than 1 cm apart. Factors associated with complete closure were evaluated in multivariable analysis. Results In total, 458 patients (age 65, 58 % men) with 494 large polyps were included. Complete clip closure of the resection defect was achieved for 338 polyps (68.4 %); closure was not complete for 156 (31.6 %). Factors associated with complete closure in adjusted analysis were smaller polyp size (odds ratio 1.06 for every millimeter decrease [95 % confidence interval 1.02–1.08]), good access (OR 3.58 [1.94–9.59]), complete submucosal lifting (OR 2.28 [1.36–3.90]), en bloc resection (OR 5.75 [1.48–22.39]), and serrated histology (OR 2.74 [1.35–5.56]). Conclusions Complete clip closure was not achieved for almost one in three resected large nonpedunculated polyps. While stable access and en bloc resection facilitate clip closure, most factors associated with clip closure are not modifiable. This highlights the need for alternative closure options and measures to prevent bleeding.

Abstract Background Pancreatic cystic lesions (PCLs) are increasingly found on cross-sectional imaging, with the majority having a low risk for malignancy. The added value of fine-needle aspiration (FNA) in risk stratification remains unclear. We evaluated the impact of three FNA needles on diagnostic accuracy, clinical management, and the ability to accrue fluid for tumor markers. Methods A multicenter prospective trial randomized 250 patients with PCLs ≥ 13 mm 2:1:1 to 19G Flex, 19G, and 22G needles with crossover for repeated FNA procedures. Diagnostic accuracy was established at 2-year follow-up, with the final diagnosis from surgical histopathology or consensus diagnosis by experts based sequentially on clinical presentation, imaging, and aspirate analysis in blinded review. Results Enrolled patients (36 % symptomatic) had PCLs in the head (44 %), body (28 %), and tail (26 %). Percentage of cyst volume aspirated was 78 % (72 % – 84 %) for 19G Flex, 74 % (64 % – 84 %) for 22G, and 73 % (63 % – 83 %) for 19G (P = 0.84). Successful FNA was significantly higher for 19G Flex (89 % [82 % – 94 %]) and 22G (82 % [70 % – 90 %]) compared with 19G (75 % [63 % – 85 %]) (P = 0.02). Repeated FNA was required more frequently in head/uncinate lesions than in body and tail (P < 0.01). Diagnostic accuracy of the cyst aspirate was 84 % (73 % – 91 %) against histopathology at 2-year follow-up (n = 79), and 77 % (70 % – 83 %) against consensus diagnosis among nonsurgical cases (n = 171). Related serious adverse events occurred in 1.2 % (0.2 % – 3.5 %) of patients. Conclusions Our study results demonstrate a statistically significant difference among the three needles in the overall success rate for aspiration, but not in the percentage of cyst volume aspirated. Flexible needles may be particularly valuable in sampling cystic PCLs in the pancreatic head/uncinate process.

Abstract Background Artificial intelligence (AI) research in colonoscopy is progressing rapidly but widespread clinical implementation is not yet a reality. We aimed to identify the top implementation research priorities. Methods An established modified Delphi approach for research priority setting was used. Fifteen international experts, including endoscopists and translational computer scientists/engineers, from nine countries participated in an online survey over 9 months. Questions related to AI implementation in colonoscopy were generated as a long-list in the first round, and then scored in two subsequent rounds to identify the top 10 research questions. Results The top 10 ranked questions were categorized into five themes. Theme 1: clinical trial design/end points (4 questions), related to optimum trial designs for polyp detection and characterization, determining the optimal end points for evaluation of AI, and demonstrating impact on interval cancer rates. Theme 2: technological developments (3 questions), including improving detection of more challenging and advanced lesions, reduction of false-positive rates, and minimizing latency. Theme 3: clinical adoption/integration (1 question), concerning the effective combination of detection and characterization into one workflow. Theme 4: data access/annotation (1 question), concerning more efficient or automated data annotation methods to reduce the burden on human experts. Theme 5: regulatory approval (1 question), related to making regulatory approval processes more efficient. Conclusions This is the first reported international research priority setting exercise for AI in colonoscopy. The study findings should be used as a framework to guide future research with key stakeholders to accelerate the clinical implementation of AI in endoscopy.