A blinded comparison of the safety and efficacy of hot biopsy forceps electrocauterization and conventional snare polypectomy for diminutive colonic polypectomy in a porcine model

Abstract

Background: Although linked with perforation, serositis, delayed bleeding, and incomplete resection, hot biopsy forceps electrocauterization (HBF) is still widely used for diminutive colonic polypectomy.

Objective: To evaluate the safety and efficacy of HBF in comparison with conventional snare polypectomy (CSP).

Design: Randomized, blinded, controlled trial.

Setting: Academic endoscopy unit.

Subjects: Ten swine.

Intervention: Eighty-two paired polypectomies (41 HBF, 41 CSP) of small, minimally elevated, artificial lesions. Standardized technique using coagulating current at 25 W. HBF: the tissue was avulsed after 1 to 2 seconds of current caused blanching of the artificial pedicle. CSP: the polyp was removed by snare diathermy.

Main outcome measurements: Histopathology of resected specimens and polypectomy sites in colectomy specimens at necropsy (lateral mucosal and depth of ulceration, necrosis and inflammation).

Results: Some (21%) of the HBF specimens were ablated and uninterpretable. All CSP specimens yielded interpretable specimens. Mucosal necrosis adjacent to HBF resection sites varied widely, between 1.5 and 9 mm (mean 5.7 mm, standard deviation ± 2). There was visible mucosa under the HBF ulcer in 14% of cases. The depth of necrosis in the colon wall was significantly different between the two techniques, with partial muscularis propria (MP) necrosis in 14 of 41 lesions (34%) with HBF, compared with 1 of 41 (2%) of CSP (P < .001), and full-thickness MP necrosis in 9 of 41 lesions (22%) with HBF, compared with 1 of 41 (2%) of CSP (P = .014). There was full-thickness MP inflammation in 13 of 41 lesions (32%) with HBF compared with 5 of 41 (12%) of CSP (P = .06). Transmural subserosal inflammation was seen in 13 of 41 lesions (32%) with HBF compared with 4 of 41 (10%) of CSP (P = .027). There was no relationship between visible lateral mucosal injury and depth of injury (rs = -0.07).

Limitations: Animal study.

Conclusion: Despite use of the standardized HBF technique, there is a wide range of lateral mucosal and deep thermal injury as well as residual target mucosa. HBF also results in a significantly greater depth of tissue injury, with a high proportion of transmural necrosis. Ensuring minimal blanching of the mucosa during the procedure does not protect from deep injury. In comparison to conventional snare polypectomy, HBF is imprecise, potentially ineffective, and hazardous.