Cold Snare,Hot Snare and APC Polypectomy for the Complete Removal of Small Left Sided Colon Polyps

Adenomatous polyps are the most common neoplastic findings discovered in subjects who undergo colonoscopy either for colorectal screening or during a diagnostic work-up for symptoms.

Currently small polyps 0.3-0.8cm are removed using hot snare polypectomy (HSP) cold snare polypectomy (CSP) while argon plasma coagulation (APC) has been proposed for the cauterization of bigger polyps ("Melt Effect") Endoscopic polypectomy is associated with potential complications, i.e. perforation and bleeding while some polyps may recur after polypectomy.

Given the limited existing data regarding the advantages and limitations of the existing techniques in the removal of colonic polyps the investigators designed a prospective study in order to compare the above mentioned methods for the compete removal of colonic polyps 0,3-0,8 cm from the left side colon.

METHODS The study will be conducted in the endoscopy unit of "Evangelismos" Hospital and in D Surgical clinic of the University Hospital "Attikon".All consecutive patients with colorectal polyps of the left colon (up to the splenic flexure) with a diameter of 0.3-0.8cm will be prospectively randomized to three groups.

• CSP: In this group polyps will be removed with the cold snare polypectomy technique, as a single piece. Additionally, a 1-2mm of normal tissue around the small polyp will also be ensnared in the CSP.
• HSP: In this group polyps will be removed with the hot snare polypectomy technique as a single piece with a electrosurgical snare and monopolar current with a setting of 30-35 W in the endocut function.
• APC: In APC group polyps will be cauterized by application of high power argon plasma coagulation on small waves at 50-60W and flow at 2lt/min.

All polyps will be elevated by submucosal injection of normal saline (1ml) and consequently a special dye (1ml) containing carbon particles (Spot) before applying any of the three removal techniques.

The injection solution protects from thermal injury of deeper layers during the application of current and APC,also the injection of the dye (tattoo) at the polypectomy, ensures that the endoscopist will detect the point of polypectomy in the follow up colonoscopy after 3-6 months.

Spot (GI supply,Camp Hill,PA) is the only commercially available suspension for endoscopic tattooing approved by the Food and Drug Association (FDA). It contains prediluted sterile syrings that are filled with highly purified fine carbon particles ready for endoscopic use.

The study excluded patients with a history of familial polyposis (FAP), Gardner's syndrome, Peutz-Jeghers syndrome, patients with colon Cancer as well as patients with idiopathic inflammatory bowel disease (IBD).

Statistical analysis showed that the sample required to give medium (W = 0.3) the difference between the three groups is 108 patients, with significance level of 5% and validity of the study 80% All patients included in the study will undergo a repeat colonoscopy in a 3-6 month time period. The endoscopist based on tattoos have been received on the first endoscopy during polypectomy will receive multiple biopsies from the point, which will be sent for histological examination.The pathologist will then examine the tissue sample and will define whereas the polyp has been completely eradicated or recurred.

Inclusion criteria

• All consecutive patients with colorectal polyps of the left colon (up to the splenic flexure) with a diameter of 0.3-0.8cm.

Exclusion criteria

• The study excluded patients with a history of familial polyposis (FAP), Gardner's syndrome, Peutz-Jeghers syndrome, patients with colon Cancer as well as patients with idiopathic inflammatory bowel disease (IBD).