Endoscopic mucosal resection using a cap: techniques for use and preventing perforation.

Endoscopic mucosal resection (EMR) is one of several local treatments that provide a specimen for histopathological analysis. The authors developed a technique of EMR using a transparent plastic cap (EMRC) in 1992. By using the EMRC procedure, any part of the gastrointestinal tract mucosa can be easily accessed. The technical details of EMRC are described. The authors have performed EMR in 380 cases of gastrointestinal lesions. The most serious complication may be perforation. Two perforations (one in the esophagus and one in the colon) have occurred. By evaluating recorded videotapes, it was determined that the lack of submucosal saline injection was the major cause. Therefore, large volume injection, which creates a large bleb and potentially reduces the risk of perforation, is recommended. Furthermore, target mucosa should be strangulated at the middle part of the created bleb (never strangulated at the base). Particularly in the colon, injecting a sufficient volume of saline and controlling the power of suction are extremely important, because the cap on the colonoscope is relatively large in size.