Postpolypectomy electrocoagulation syndrome

INTRODUCTION

Postpolypectomy electrocoagulation syndrome (also known as postpolypectomy syndrome and transmural burn syndrome) refers to the development of abdominal pain, fever, leukocytosis, and peritoneal inflammation in the absence of frank perforation that occurs after polypectomy with electrocoagulation. Recognition of postpolypectomy syndrome is important to avoid unnecessary exploratory laparotomy since it resolves with conservative treatment in the majority of patients.

INCIDENCE

• Postpolypectomy syndrome was reported in six patients out of 16,318 colonoscopies performed between 1994 and 2002 in a large integrated health system [1].
• Earlier reports estimated it to occur in 0.5 to 1.2 percent of patients undergoing polypectomy [2,3].
• Another series described three types of cautery injury in 4784 consecutive polypectomies [4]. Two patients had frank perforation and five had "mini-perforation," while 24 (0.5 percent) developed the postpolypectomy electrocoagulation syndrome.
• Another report included 1190 patients who underwent 1576 polypectomies [5]. Postpolypectomy syndrome was the second most common complication (after bleeding) occurring in 0.5 percent of polypectomies. In contrast, no cases were described in a report involving 1672 polypectomies [6].

The increasing adoption of submucosal saline elevation of large polyps prior to transection may have reduced the incidence of postpolypectomy syndrome in recent years but there are no large studies. The saline "cushion" increases the thickness of the submucosal layer, and as such may reduce the risk of transmural thermal injury. (See "Endoscopic removal of large colonic polyps".)

PATHOGENESIS

Postpolypectomy syndrome develops when electrical current applied during polypectomy extends past the mucosa into the muscularis propria and serosa, resulting in a transmural burn without perforation [7]. Serosal irritation leads to a localized inflammatory response that manifests clinically as a localized peritonitis [4].

Postpolypectomy syndrome occurs most often after the removal of large (>2 cm) sessile polyps, which usually require large amounts and long duration of thermal energy [4]. Inadvertent capture of a piece of normal adjacent mucosa within the snare loop during snare placement over a polyp can result in this condition when cautery transects both portions of tissue (mucosa and polyp) (figure 1) [7].