Project description:BACKGROUND:Although prophylactic clip application before polypectomy may prevent postpolypectomy bleeding (PPB), the usefulness of prophylactic clipping in the treatment of large pedunculated polyps is controversial in some prospective randomized studies. This study was conducted to evaluate the efficacy of prophylactic clip application and to investigate the predictors of PPB in large pedunculated colorectal polyps. METHODS:A total of 137 pedunculated polyps (size ?1?cm) in 116 patients were prospectively included and randomized into group A (with clipping) and group B (without clipping), and resected. The occurrences of immediate PPB (graded 1-4) and delayed PPB were compared. RESULTS:Sixty-seven polyps were allocated in group A and 70 polyps in group B. In both groups, the median polyp diameter was 15?mm (P?=?0.173) and the median stalk diameter was 3?mm (P?=?0.362). Twenty-eight (20.4%) immediate PPB episodes in 137 polyps occurred, 6 (9.0%) in group A and 22 (31.4%) in group B (P?=?0.001). However, the occurrence of delayed PPB was not different between the groups (P?=?0.943). Prophylactic clip application decreased the occurrence of immediate PPB (odds ratio 0.215, 95% confidence interval 0.081-0.571). Moreover, polyp size ?20?mm and stalk diameter???4?mm increased the risk of immediate PPB. CONCLUSIONS:Clip application before polypectomy of ?1?cm pedunculated polyps is effective in decreasing the occurrence of immediate PPB. Thus, clip application should be considered before performing snare polypectomy, especially for large polyps with a thick stalk. TRIAL REGISTRATION:This research was studied a prospective maneuver and enrolled in a registry of clinical trials run by United States National Library of Medicine at the National Institutes of Health (ClinicalTrials.gov Protocol Registration and Results system ID: NCT01437631). This study was registered on September 19, 2011.
Project description:We studied factors influencing colon postpolypectomy bleeding (PPB), with a focus on antithrombotic and anticoagulation therapy.We conducted a retrospective case-control study of all patients who underwent polypectomy at our tertiary referral center in Italy between 2007 and 2014. Polyp characteristics (number of polyps removed per patient, size, morphology, location, resection technique, prophylactic hemostasis methods) and patient characteristics (age, sex, comorbidities, medication) were analyzed.The case and control groups included 118 and 539 patients, respectively. The two groups differed in the frequency of comorbidities (69% vs. 40%, p=0.001), polyps removed (27% vs. 18%, p=0.02), and use of heparin therapy (23% vs. 1%, p<0.001). A total of 279 polyps in the case group and 966 in the control group were nonpedunculated (69% vs. 81%, p=0.01) and measured ?10 mm (78% vs. 32%, p=0.001). Multivariate analysis showed that polyps ?10 mm (odds ratio [OR], 6.1; 95% confidence interval [CI], 2.3-15.5), administration of heparin (OR, 16.5; 95% CI, 6.2-44), comorbidity (OR, 2.3; 95% CI, 1.4-3.9), and presence of ?2 risk factors (OR, 3.2; 95% CI, 1.7-6.0) were associated with PPB.The incidence of PPB increases with polyp size ?10 mm, heparin use, comorbidity, and presence of ?2 risk factors.
Project description:Background and Aims: Postpolypectomy bleeding and incomplete polyp removal are important complication and quality concerns of colonoscopy for colon cancer prevention. We investigated if endoscopic mucosal stripping (EMS) as a technical modification of traditional cold snare polypectomy to avoid submucosal injury during removal of non-pedunculated colon polyps could prevent postpolypectomy bleeding and facilitate complete polyp removal. Methods: This is an Internal Review Board exemption-granted retrospective analysis of 5,142 colonoscopies with snare polypectomy performed by one of the authors (ZJC) at Minnesota Gastroenterology ambulatory endoscopy centers during a 12-year period divided into pre-EMS era (2005-2012, n = 2,973) and EMS era (2013-2016, n = 2169) with systemic adoption of EMS starting 2013. Change in postpolypectomy bleeding rate before and after EMS adoption and EMS polypectomy completeness were evaluated. Results: Zero postpolypectomy bleeding case was found during EMS era (rate 0%) compared with 10 bleeding cases during pre-EMS era (rate 0.336%). This difference was statistically significant (P = 0.0055) and remained so after excluding 2 bleeding cases of pedunculated polyps (P = 0.012). All bleeding cases involved hot snare polypectomy. Histological examination of the involved polyps showed substantial submucosal vascular damage in contrast to a remarkable paucity of submucosa in comparable advanced polyps removed using EMS. Both biopsy and follow-up colonoscopy examination of the polypectomy sites confirmed that EMS more completely removed non-pedunculated advanced polyps. Conclusions: EMS polypectomy was effective in preventing postpolypectomy bleeding and facilitated complete polyp removal.
Project description:Accidental swallowing of press-through package (PTP) sheets that could cause esophageal perforation is commonly encountered in emergency departments requiring early detection and removal. We report a case in which an accidentally swallowed PTP sheet was removed from the esophagus using a detachable snare after usual endoscopic methods proved ineffective. A Japanese woman in her 60s visited the emergency department with a persistent sore throat. Cervicothoracic computed tomography revealed presence of a PTP sheet in the cervical esophagus, and emergency endoscopy was performed. Pre-endoscopy simulations using a sheet identical to the one swallowed by the patient indicated that the sheet would not have been retrievable using an overtube (its inner diameter was smaller than the sheet's diameter) and grasping forceps (they slipped off the sheet). It was successfully removed using a detachable snare, a device normally employed in colorectal polypectomy, allowing us to ligate the end of the sheet and pull it into the overtube. To the best of our knowledge, this is the first report of endoscopic removal of a PTP sheet from the esophagus using a detachable snare. We suggest that this novel method would facilitate removal of esophageal PTP sheets.
Project description:Prophylactic platelet transfusions are used to reduce the risk of spontaneous bleeding in patients with treatment- or disease-related severe thrombocytopenia. A prophylactic platelet-transfusion threshold of <10 × 103/µL has been shown to be safe in stable hematology/oncology patients. A higher threshold and/or larger or more frequent platelet doses may be appropriate for patients with clinical features associated with an increased risk of bleeding such as high fevers, sepsis, disseminated intravascular coagulation, anticoagulation therapy, or splenomegaly. Unique factors in the outpatient setting may support the use of a higher platelet-transfusion threshold and/or dose of platelets. A prophylactic platelet-transfusion strategy has been shown to be associated with a lower risk of bleeding compared with no prophylaxis in adult patients receiving chemotherapy but not for autologous transplant recipients. Despite the use of prophylactic platelet transfusions, a high incidence (50% to 70%) of spontaneous bleeding remains. Using a higher threshold or larger doses of platelets does not change this risk. New approaches to reduce the risk of spontaneous bleeding, including antifibrinolytic therapy, are currently under study.
Project description:Thrombocytopenia (TCP) may cause severe and life-threatening bleeding. While this may be prevented by platelet transfusions, transfusions are associated with potential complications, do not always work (platelet refractory) and are not always available. There is an urgent need for a synthetic alternative. We evaluated the ability of fibrinogen-coated nanospheres (FCNs) to prevent TCP-related bleeding. FCNs are made of human albumin polymerized into a 100-nm sphere and coated with fibrinogen. We hypothesized that FCNs would bind to platelets through fibrinogen-GPIIb/IIIa interactions, contributing to hemostasis in the setting of TCP. We used two murine models to test these effects: in the first model, BALB/c mice received 7.25 Gy total-body irradiation (TBI); in the second model, lower dose TBI (7.0 Gy) was combined with an anti-platelet antibody (anti-CD41) to induce severe TCP. Deaths in both models were due to gastrointestinal or intracranial bleeding. Addition of antiplatelet antibody to 7.0 Gy TBI significantly worsened TCP and increased mortality compared to 7.0 Gy TBI alone. FCNs significantly improved survival compared to saline control in both models, suggesting it ameliorated TCP-related bleeding. Additionally, in a saphenous vein bleeding model of antibody-induced TCP, FCNs shortened bleeding times. There were no clinical or histological findings of thrombosis or laboratory findings of disseminated intravascular coagulation after FCN treatment. In support of safety, fluorescence microscopy suggests that FCNs bind to platelets only upon platelet activation with collagen, limiting activity to areas of endothelial damage. To our knowledge, this is the first biosynthetic agent to demonstrate a survival advantage in TCP-related bleeding.
Project description:Postpolypectomy surveillance has become a major indication for colonoscopy as a result of increased use of screening colonoscopy in Korea. In this report, a careful analytic approach was used to address all available evidences to delineate the predictors for advanced neoplasia at surveillance colonoscopy and we elucidated the high risk findings of the index colonoscopy as follows: 3 or more adenomas, any adenoma larger than 10 mm, any tubulovillous or villous adenoma, any adenoma with high-grade dysplasia, and any serrated polyps larger than 10 mm. Surveillance colonoscopy should be performed five years after the index colonoscopy for those without any high-risk findings and three years after the index colonoscopy for those with one or more high risk findings. However, the surveillance interval can be shortened considering the quality of the index colonoscopy, the completeness of polypectomy, the patient's general condition, and family and medical history.
Project description:Eukaryotic cell homeostasis requires transfer of cellular components among organelles and relies on membrane fusion catalyzed by SNARE proteins. Inactive SNARE bundles are reactivated by hexameric N-ethylmaleimide-sensitive factor, vesicle-fusing ATPase (Sec18/NSF)-driven disassembly that enables a new round of membrane fusion. We previously found that phosphatidic acid (PA) binds Sec18 and thereby sequesters it from SNAREs and that PA dephosphorylation dissociates Sec18 from the membrane, allowing it to engage SNARE complexes. We now report that PA also induces conformational changes in Sec18 protomers and that hexameric Sec18 cannot bind PA membranes. Molecular dynamics (MD) analyses revealed that the D1 and D2 domains of Sec18 contain PA-binding sites and that the residues needed for PA binding are masked in hexameric Sec18. Importantly, these simulations also disclosed that a major conformational change occurs in the linker region between the D1 and D2 domains, which is distinct from the conformational changes that occur in hexameric Sec18 during SNARE priming. Together, these findings indicate that PA regulates Sec18 function by altering its architecture and stabilizing membrane-bound Sec18 protomers.