Colonoscopy has been shown to be an effective modality to prevent colorectal cancer(CRC)development.CRC reduction is achieved by detecting and removing adenomas,which are precursors of CRC.Most colorectal polyps are s...Colonoscopy has been shown to be an effective modality to prevent colorectal cancer(CRC)development.CRC reduction is achieved by detecting and removing adenomas,which are precursors of CRC.Most colorectal polyps are small and do not pose a significant challenge for trained and skilled endoscopists.However,up to 15%of polyps are considered“difficult”,potentially causing life-threatening complications.A difficult polyp is defined as any polyp that is challenging for the endoscopist to remove owing to its size,shape,or location.Advanced polypectomy techniques and skills are required to resect difficult colorectal polyps.There were various polypectomy techniques for difficult polyps such as endoscopic mucosal resection(EMR),underwater EMR,Tip-in EMR,endoscopic submucosal dissection(ESD),or endoscopic full-thickness resection.The selection of the appropriate modality depends on the morphology and endoscopic diagnosis.Several technologies have been developed to aid endoscopists in performing safe and effective polypectomies,especially complex procedures such as ESD.These advances include video endoscopy system,equipment assisting in advanced polypectomy,and closure devices/techniques for complication management.Endoscopists should know how to use these devices and their availability in practice to enhance polypectomy performance.This review describes several useful strategies and tips for managing difficult colorectal polyps.We also propose the stepwise approach for difficult colorectal polyps.展开更多
Approximately 7%-29%of patients with colorectal cancer present with colonic obstruction.The concept of self-expandable metal stent(SEMS)insertion as a bridge to surgery(BTS)is appealing.However,concerns on colonic ste...Approximately 7%-29%of patients with colorectal cancer present with colonic obstruction.The concept of self-expandable metal stent(SEMS)insertion as a bridge to surgery(BTS)is appealing.However,concerns on colonic stenting possibly impairing oncologic outcomes have been raised.This study aimed to review current evidence on the short-and long-term oncologic outcomes of SEMS insertion as BTS for left-sided malignant colonic obstruction.For short-term outcomes,colonic stenting facilitates a laparoscopic approach,increases the likelihood of primary anastomosis without a stoma,and may decrease postoperative morbidity.However,SEMS-related perforation also increases local recurrence and impairs overall survival.Moreover,colonic stenting may cause negative oncologic outcomes even without perforation.SEMS can induce shear forces on the tumor,leading to increased circulating cancer cells and aggressive pathological characteristics,including perineural and lymphovascular invasion.The conflicting evidence has led to discordant guidelines.Well-designed collaborative studies that integrate both oncologic outcomes and data on basic research(e.g.,alteration of circulating tumors)are needed to clarify the actual benefit of colonic stenting as BTS.展开更多
文摘Colonoscopy has been shown to be an effective modality to prevent colorectal cancer(CRC)development.CRC reduction is achieved by detecting and removing adenomas,which are precursors of CRC.Most colorectal polyps are small and do not pose a significant challenge for trained and skilled endoscopists.However,up to 15%of polyps are considered“difficult”,potentially causing life-threatening complications.A difficult polyp is defined as any polyp that is challenging for the endoscopist to remove owing to its size,shape,or location.Advanced polypectomy techniques and skills are required to resect difficult colorectal polyps.There were various polypectomy techniques for difficult polyps such as endoscopic mucosal resection(EMR),underwater EMR,Tip-in EMR,endoscopic submucosal dissection(ESD),or endoscopic full-thickness resection.The selection of the appropriate modality depends on the morphology and endoscopic diagnosis.Several technologies have been developed to aid endoscopists in performing safe and effective polypectomies,especially complex procedures such as ESD.These advances include video endoscopy system,equipment assisting in advanced polypectomy,and closure devices/techniques for complication management.Endoscopists should know how to use these devices and their availability in practice to enhance polypectomy performance.This review describes several useful strategies and tips for managing difficult colorectal polyps.We also propose the stepwise approach for difficult colorectal polyps.
文摘Approximately 7%-29%of patients with colorectal cancer present with colonic obstruction.The concept of self-expandable metal stent(SEMS)insertion as a bridge to surgery(BTS)is appealing.However,concerns on colonic stenting possibly impairing oncologic outcomes have been raised.This study aimed to review current evidence on the short-and long-term oncologic outcomes of SEMS insertion as BTS for left-sided malignant colonic obstruction.For short-term outcomes,colonic stenting facilitates a laparoscopic approach,increases the likelihood of primary anastomosis without a stoma,and may decrease postoperative morbidity.However,SEMS-related perforation also increases local recurrence and impairs overall survival.Moreover,colonic stenting may cause negative oncologic outcomes even without perforation.SEMS can induce shear forces on the tumor,leading to increased circulating cancer cells and aggressive pathological characteristics,including perineural and lymphovascular invasion.The conflicting evidence has led to discordant guidelines.Well-designed collaborative studies that integrate both oncologic outcomes and data on basic research(e.g.,alteration of circulating tumors)are needed to clarify the actual benefit of colonic stenting as BTS.
