title: Insulated-tip knife endoscopic mucosal resection of large colorectal polyps unsuitable for standard polypectomy.
abstract: OBJECTIVE
  Endoscopic mucosal resection (EMR) has been shown to be safe and effective. En bloc resection is often not achieved using conventional EMR. Insulated-tip knife (It-knife) EMR has been recently proposed for early gastric cancer dissection and removal. This study was conducted to evaluate the safety and efficacy in obtaining en bloc resection with It-knife EMR of large colonic lesions not resectable with standard endoscopic techniques.
  
  
  METHODS
  A total of 29 patients (19 men, 10 women, mean age 67.5 yr, range 44-88) were included in the study. Lesions were considered not suitable for standard polypectomy because of large diameter (>3 cm), morphology, and/or position. Lesions were located in the rectum (N = 11), sigmoid: (N = 10), descending: (N = 4), transverse: (N = 2), and hepatic flexure (N = 2). After saline injection, circumferential incision and dissection of the lesions were attempted with the aim of achieving en bloc resection.
  
  
  RESULTS
  En bloc resection was achieved in only 55.1% of the lesions (16 out of 29 patients). In the remaining cases, resection was completed with a piecemeal technique. The median size of the en bloc resected specimen was 3 x 3.4 cm. Complications occurred in four patients (13.7%). At histopathology, 13 patients had low-grade dysplasia, 15 high-grade dysplasia. One patient had a tumor invading the submucosa and was submitted to surgery.
  
  
  CONCLUSIONS
  It-knife EMR is a promising technique for attempting en bloc resection of large colonic polyps. Adequate training and caution are required because it can be associated with a higher complication rate than with other EMR modalities.
authors.affiliation: Department of Gastroenterology, IRCCS Istituto Clinico Humanitas, Milano, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Repici
authors.forename: Massimo
authors.initials: M
authors.lastname: Conio
authors.forename: Claudio
authors.initials: C
authors.lastname: De Angelis
authors.forename: Anna
authors.initials: A
authors.lastname: Sapino
authors.forename: Alberto
authors.initials: A
authors.lastname: Malesci
authors.forename: Alberto
authors.initials: A
authors.lastname: Arezzo
authors.forename: Cristina
authors.initials: C
authors.lastname: Hervoso
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Pellicano
authors.forename: Salvatore
authors.initials: S
authors.lastname: Comunale
authors.forename: Mario
authors.initials: M
authors.lastname: Rizzetto
mesh_terms: D000328:Adult; D000368:Aged; D003111:Colonic Polyps / Q000473:pathology / Q000601:surgery*; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged