Endoscopic Treatment of Gastric Adenoma with Argon Plasma Coagulation

The term gastric adenoma means a benign lesion of the glandular epithelium having variable degrees of cellular atypia and showing papillary or tubular structures. Because long-term follow-up studies of gastric adenomas reveal malignant transformations, it is well known they are premalignant. Since these lesions lie histologically and clinically on the borderline of between whether they are benign or malignant, it is extremely important for clinicians to determine whether they are to be treated or not (Morson, 1980; Kamiya, 1982; Rugge, 1994). For a long time, there was no specific treatment policy of gastric adenomas and treatment varied from close endoscopic follow-ups to endoscopic resection, considering its heterogeneous clinical consequences (Di Gregorio, 1993; Saraga, 1987). When gastric epithelial dysplasia is classified using the two or three tier system, each group shows a different clinical course. For gastric adenoma with high grade dysplasia (HGD), endoscopic resection has become the standard treatment because of risk of malignant progression and synchronous carcinomas (Lansdown, 1990; Farinati, 1993). Many western publications have recommended close endoscopic follow-up of patients with moderate/low grade gastric epithelial dysplasia (Rugge, 1991, Fertitta, 1993; Rugge, 1991). The frequency of the followup has been recommended to be every three to 12 months at least during the first year, but it is still unknown of how long the follow-up should be maintained for when no progression has been detected (Bearzi, 1994; Fertitta, 1993). The disadvantages of endoscopic follow-ups are patient anxiety, risk of disease progression, and low patient compliance for an undefined period (Lansdown, 1990; Rugge, 1991). Though endoscopic resection has become frequently applied for gastric adenoma with low grade dysplasia (LGD), there is ongoing controversy considering its relatively benign natural course and clinical significance. Although endoscopic resection is a less invasive procedure than surgical resection, it still carries the risk of complications and requires hospitalization of several days (Ono 2001, O'Mahony, 2001; Miyata 2000). Argon plasma coagulation (APC) is a kind of non-contact technique for tissue coagulation, which transfers high-frequency electric current through ionized argon gas to targeted lesions (Grund, 1994; Grunde, 1997). Because APC has an advantage of confining the thermal effect to the superficial layer of the gastrointestinal wall, APC has been used for the treatment of bleeding ulcers, hemorrhagic telangiectasias, and tumors (Chau, 2003;