Flat and sessile lesions are being identified more frequently because of increased awareness, improved endoscopic skills, and enhanced imaging.
The defiant polyp is a lesion identified at colonoscopy that defies resection by the standard snare polypectomy technique.
Increasingly, the defiant polyps undergoes photodocumentation and tissue sampling, and the patient is referred for an attempt at curative colonoscopic resection.
Dr Anna Buchner and colleagues from Pennysylvania, USA evaluated the current nature of the defiant polyps and outcomes of their endoscopic resection.
|Procedure-related adverse events were recorded in 12% of patients|
Patients with colorectal polyps not amenable to standard snare polypectomy were referred to a single endoscopist at a tertiary center for an attempt at curative endoscopic resection.
The indication defiant polyp was applied prospectively, as defined previously, beginning in 2007.
An electronic endoscopy report database was searched for this indication from 2007 to 2009 for a single endoscopist at an endoscopy referral center.
Data pertaining to patient age and sex, polyp site and histopathology, resection technique, use of adjunctive ablation, adverse events, and residual/recurrent neoplasia at follow-up were culled.
Submucosal injection of varying quantities of normal saline solution tinted with methylene blue dye was used for endoscopic resection.
Standard and mini-snares were used with pure coagulation current.
The team's main outcome measurements include complete resection, complications, recurrence.
The research team evaluated 274 patients with a total of 315 defiant polyps who were referred for attempted endoscopic resection.
The majority of defiant polyps were located in the right side of the colon.
The mean size was estimated at 23 mm.
In 10% of defiant polyps, surgery was required because endoscopic resection was deemed unsuitable because of the unfavorable appearance, the location, or the inability to lift or because of submucosal invasion on post-EMR histopathology.
Complete endoscopic eradication was achieved in a single session in 91% of defiant polyps.
En bloc resection was performed in 54% of polyps, and piecemeal resection in 46%.
Histopathology revealed 56% of tubular adenomas, 20% of serrated adenomas, 9% of tubulovillous adenomas, 3% of hyperplastic polyps, and 5% of adenocarcinomas.
Adjunctive ablation of focal residual neoplastic tissue was applied in 24% of defiant polpys to achieve complete endoscopic eradication.
Procedure-related adverse events were recorded in 12% of patients.
Acute bleeding occurred in 9 patients.
There was 1 microperforation managed with clip closure and antibiotics.
Delayed bleeding was observed in 7% of patients, of whom 8 required hospitalization, and 4 colonoscopy for hemostasis.
Among the patients who underwent follow-up surveillance colonoscopy, residual/recurrent neoplastic tissue at the site of the previous EMR was identified in 27%.
Residual/recurrent neoplasia was successfully eradicated with further endoscopic resection or ablation.
Dr Buchner's team concludes, "Dediant polyps consist predominantly of sessile and flat adenomas including serrated adenomas."
"Most defiant polpys can be successfully eradicated at dedicated therapeutic colonoscopy by using adjunctive resection and ablation techniques."
"The Complete endoscopic eradication rate is high and the adverse event rate is low."
"A relatively high rate of local residual/recurrent neoplasia at the resection site underscores the importance of follow-up colonoscopy."