Colonic mucosal dissection following electrocautery or laser polypectomy

Mucosal proctectomy and ileoanal anastomosis is being increasingly performed on patients with familial polyposis, many of whom have undergone previous subtotal colectomy followed by endoscopic surveillance and polypectomy with monopolar electrocautery (MPEC) or, more recently, argon laser (AL). Our aim was to compare the ease of mucosal dissection following polypectomy with MPEC or AL in the canine colon. At celiotomy, two groups of fifteen 5- to 7-mm sessile polyps were surgically created in the descending colon of five mongrel dogs. Six weeks later, each animal underwent flexible colonoscopy and polyp fulguration with MPEC (15 polyps) and AL (15 polyps). Fulguration was performed weekly for 2-3 weeks until all polyps had been obliterated. Ten weeks later, mucosal dissection was performed with the operating team unaware of prior treatment. Mucosal dissection was scored for dissectability (1 to 4; 1 = facile, 4 = difficult), blood loss, operating time, and number of mucosal perforations with the last three parameters normalized to 100 cm2 of mucosa. AL and MPEC were equally effective at polyp obliteration; however, more AL-treated polyps required retreatment than MPEC-treated polyps (P less than 0.05). After AL treatment, mucosal dissection was more facile [dissectability index (mean +/- SEM): 1.4 +/- 0.2 vs 2.6 +/- 0.2; P less than 0.05] and could be performed more quickly (15.1 +/- 2.4 min vs 23.6 +/- 2.7 min; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)