Safety of endoscopic procedures with monopolar versus bipolar instruments in an ex vivo porcine model

Abstract

Background: Monopolar instruments are generally used in colorectal endoscopic mucosal resection (EMR). Bipolar instruments have previously been reported to be as safe as monopolar instruments. We sought to compare the safety of the monopolar and bipolar snare and hemostatic forceps in an animal model. Methods: We created 5-mm, 10-mm, and 15-mm target lesions on an ex vivo porcine rectum. Two lesions of each size were resected via monopolar polypectomy (M-P), monopolar EMR (M-E), bipolar polypectomy (B-P), and bipolar EMR (B-E). We performed a pathological evaluation of the conditions of perforation and the effects of burning on the tissues. In addition, we burned the muscularis propria covered with submucosal layer using monopolar and bipolar hemostatic forceps and performed pathological evaluations. Results: Polypectomy and EMR were performed in a total of 24 target lesions. A perforation was found on histology in one case of M-P and one case of M-E after removing target lesions of 15 mm in diameter. There were no perforations during endoscopic resection using the bipolar snare. The thermal denaturation in B-P did not reach the muscularis propria layer regardless of the size of the target lesion. Although thermal damage after using monopolar hemostatic forceps was extensive, thermal denaturation was only seen on the surface of the submucosal layer when bipolar hemostatic forceps were used. Conclusions: Bipolar instruments cause less damage to the tissue than monopolar instruments. Our results also suggest that bipolar instruments may be safer than monopolar instruments in endoscopic procedures for colorectal lesions.

Preclinical Assessment of Tissue Effects by Gastrointestinal Endoscope Tip Temperature

“…Regarding the applied experimental setup in general, it has to be emphasized that histopathological examination of ex vivo tissue samples is suitable for detection of immediate, direct physical tissue damage due to exposure to mechanical and/or thermal insults (such as thermal denaturation of proteins or crushing of tissue), 18 whereas indirect and subsequent effects on cells in vivo, leading to cellular dysfunction with delayed cellular degeneration and/or cell death, cannot be unreservedly reliably captured.…”

Novel clip device for prevention of bleeding after endoscopic papillectomy

“…Bipolar forceps were used to reduce the depth of burning and tissue destruction. 24, , 25 However, bleeding from the mucosal break after EP is often refractory (Figure 3 ). In one case where the endoscopic hemostasis was not successful, transarterial embolization was performed by a radiologist as an emergency intervention.…”

“…Electrical hemostatic forceps were used when an arterial bleeding point or injured vessel could be directly observed. Bipolar forceps were used to reduce the depth of burning and tissue destruction 24, 25 . However, bleeding from the mucosal break after EP is often refractory (Figure 3).…”

En bloc resection of large colonic polyps with Bipolar snare; two video cases

“…We demonstrate EMR with bipolar snare (B-EMR) in two video cases in which en bloc resections were successfully and safely achieved in 10 minutes. For eligible large polyps, time-consuming ESD can be substituted by the easier and safer B-EMR with securing en bloc resection 1 .…”