Background and Study Aims: It has been postulated that chronic radiation proctopathy, clinically manifested by hematochezia and by the appearance of multiple telangiectasias, is caused by ischemia. This theory is base...Background and Study Aims: It has been postulated that chronic radiation proctopathy, clinically manifested by hematochezia and by the appearance of multiple telangiectasias, is caused by ischemia. This theory is based on reports that appeared in the 1980s which described obliterative endarteritis in patients with chronic radiation-induced ulcers. However, bleeding from radiation proctopathy is typically successfully treated endoscopically by widespread tissue coagulation, and the complications that would be expected to occur if the tissue was ischemic, such as poor wound healing, generally do not arise. We therefore hypothesized that the ischemia theory is incorrect and that rectal capillary oxygen saturation is normal in patients with telangiectasias of chronic radiation proctopathy. Patients and Methods: We developed a visible-light spectroscopy device that measures mucosal capillary hemoglobin oxygen saturation during endoscopy (having reported its operating characteristics previously). We prospectively studied 20 patients who had typical findings of multiple rectal telangiectasias, 1-20 years after undergoing external-beam irradiation for prostate or rectal carcinoma. We measured and compared the mucosal capillary oxygen saturations in the affected areas of the distal rectum and in endoscopically normal areas in the rectosigmoid colon. Results: Mucosal oxygenation was normal in all 20 patients in affected areas (64%-80%) and in unaffected areas (63%-75%). The mean mucosal hemoglobin oxygen saturation was actually slightly higher in the affected areas of the rectum than in the uninvolved rectosigmoid colon (73%vs. 69%, P < 0.01). Conclusions: The common form of chronic radiation proctopathy, characterized by multiple telangiectasias without ulcers or strictures, is not associated with ongoing mucosal ischemia. This finding may explain why endoscopic treatment of this disorder, in which large areas of the mucosa are coagulated with argon plasma or other treatment modalities that cause widespread ulceration, does not typically result in complications from poor wound healing.展开更多
Background: According to current practice guidelines for performance of colonoscopy in patients requiring long-term anticoagulation, polypectomy is considered a high-risk procedure for which anticoagulation must tempo...Background: According to current practice guidelines for performance of colonoscopy in patients requiring long-term anticoagulation, polypectomy is considered a high-risk procedure for which anticoagulation must temporarily be discontinued. However, these guidelines are based on expert opinion, and the bleeding risk after polypectomy in anticoagulated patients is not known. Objective: Measure the risk of postpolypectomy bleeding in patients who undergo colonoscopic polypectomy while anticoagulated. Design: Retrospective review of patients who underwent polypectomy without discontinuation of anticoagulation. Setting: Veterans Administration Palo Alto Health Care System. Patients: Forty-one polypectomies were performed in 21 patients. All patients had been receiving long-term anticoagulation with warfarin; the average international normalized ratio was 2.3 (range 1.4-4.9; normal 0.9-1.2). To prevent supratherapeutic anticoagulation, warfarin was with-held for 36 hours before the procedure while the patients were on a liquid diet. The average polyp size was 5 mm (range 3-10 mm). Interventions: All patients underwent polypectomy followed immediately by prophylactic application of one or two clips to prevent bleeding. Main Outcome Measurements: Rate of postpolypectomy bleeding. Results: There were no episodes of postpolypectomy bleeding. The 95%CI for the risk of bleeding was 0%to 8.6%when analyzed per polypectomy and 0%to 15%when analyzed per patient. Limitations: Small single-center retrospective study. Conclusions: Our experience suggests that small polyps can be removed with a very low risk of bleeding when clips are applied immediately after polypectomy. If these results can be confirmed in a larger multicenter study, our protocol may become an alternative to withholding anticoagulation in patients at high risk of thrombosis.展开更多
文摘Background and Study Aims: It has been postulated that chronic radiation proctopathy, clinically manifested by hematochezia and by the appearance of multiple telangiectasias, is caused by ischemia. This theory is based on reports that appeared in the 1980s which described obliterative endarteritis in patients with chronic radiation-induced ulcers. However, bleeding from radiation proctopathy is typically successfully treated endoscopically by widespread tissue coagulation, and the complications that would be expected to occur if the tissue was ischemic, such as poor wound healing, generally do not arise. We therefore hypothesized that the ischemia theory is incorrect and that rectal capillary oxygen saturation is normal in patients with telangiectasias of chronic radiation proctopathy. Patients and Methods: We developed a visible-light spectroscopy device that measures mucosal capillary hemoglobin oxygen saturation during endoscopy (having reported its operating characteristics previously). We prospectively studied 20 patients who had typical findings of multiple rectal telangiectasias, 1-20 years after undergoing external-beam irradiation for prostate or rectal carcinoma. We measured and compared the mucosal capillary oxygen saturations in the affected areas of the distal rectum and in endoscopically normal areas in the rectosigmoid colon. Results: Mucosal oxygenation was normal in all 20 patients in affected areas (64%-80%) and in unaffected areas (63%-75%). The mean mucosal hemoglobin oxygen saturation was actually slightly higher in the affected areas of the rectum than in the uninvolved rectosigmoid colon (73%vs. 69%, P < 0.01). Conclusions: The common form of chronic radiation proctopathy, characterized by multiple telangiectasias without ulcers or strictures, is not associated with ongoing mucosal ischemia. This finding may explain why endoscopic treatment of this disorder, in which large areas of the mucosa are coagulated with argon plasma or other treatment modalities that cause widespread ulceration, does not typically result in complications from poor wound healing.
文摘Background: According to current practice guidelines for performance of colonoscopy in patients requiring long-term anticoagulation, polypectomy is considered a high-risk procedure for which anticoagulation must temporarily be discontinued. However, these guidelines are based on expert opinion, and the bleeding risk after polypectomy in anticoagulated patients is not known. Objective: Measure the risk of postpolypectomy bleeding in patients who undergo colonoscopic polypectomy while anticoagulated. Design: Retrospective review of patients who underwent polypectomy without discontinuation of anticoagulation. Setting: Veterans Administration Palo Alto Health Care System. Patients: Forty-one polypectomies were performed in 21 patients. All patients had been receiving long-term anticoagulation with warfarin; the average international normalized ratio was 2.3 (range 1.4-4.9; normal 0.9-1.2). To prevent supratherapeutic anticoagulation, warfarin was with-held for 36 hours before the procedure while the patients were on a liquid diet. The average polyp size was 5 mm (range 3-10 mm). Interventions: All patients underwent polypectomy followed immediately by prophylactic application of one or two clips to prevent bleeding. Main Outcome Measurements: Rate of postpolypectomy bleeding. Results: There were no episodes of postpolypectomy bleeding. The 95%CI for the risk of bleeding was 0%to 8.6%when analyzed per polypectomy and 0%to 15%when analyzed per patient. Limitations: Small single-center retrospective study. Conclusions: Our experience suggests that small polyps can be removed with a very low risk of bleeding when clips are applied immediately after polypectomy. If these results can be confirmed in a larger multicenter study, our protocol may become an alternative to withholding anticoagulation in patients at high risk of thrombosis.
