Application of Endoscopic Ultrasonography in the Diagnosis and Treatment of Lower Gastrointestinal Disease

they report new findings on the use of EUS-guided sampling in 30 patients with rectal and perirectal lesions which include the previously reported cases. Surprisingly enough, the diagnostic accuracy of EUS-FNA/FNB was only 67% (20/30) this time, which means that merely 10 accurate diagnoses were obtained after performing 19 additional consecutive procedures. Diagnostic accuracy of subepithelial tumor (SET) was only 50% (5/10) and that of non-SET was 75% (15/20). They concluded that the size of the lesion was an important factor for the diagnostic accuracy of EUS-guided sampling of rectal SET. While the three SETs included in their first report measured 44 mm, 30 mm, and 50 mm in size, among 10 SETs included in this paper, only 5 of them were larger than 20 mm in size. This factor may somewhat explain the discrepancies in EUS-guided sampling accuracy between their two reports. Nevertheless, their diagnostic accuracy of EUS-guided sampling of rectal and perirectal lesions is lower than that of previous studies ranging 90−95.5%. 4-6 The authors speculated that absence of on-site cytopathologist could be one of the reasons of the lower accuracy seen in this study. The result of EUS-guided sampling can also be influenced by the various factors such as experience of endosonographer, used instrument and technique. The authors did not mention on the practiced endosonographer(s) at all in their previous report, and in this article, they just disclosed the fact that five endosonographers performed the procedures, but did not provide additional information on them. In addition, a close Endoscopic ultrasonography (EUS) currently plays an important role in the field of gastroenterology, particularly in the diagnosis and treatment of upper gastrointestinal (GI) and pancreatobiliary diseases. However, it remains under-used in the lower GI diseases field, probably because of the lack of knowledge and experience of endosonographers. The diagnostic value of EUS is well demonstrated in the local staging of rectal cancer, and it also shows benefits in the differential diagnosis of submucosal tumors of the lower GI tract; assessment of IBD with or without perirectal fistula; evaluation of perianal and perirectal inflammatory conditions ; and evaluation of anal sphincters. 1 In this issue of Intestinal Research, Soh et al. 2 reported their experience of EUS-guided fine needle aspiration (FNA) and biopsy (FNB) for rectal and perirectal lesions. Previously, in 2011, the authors reported their outcome of EUS-FNA and trucut biopsy (TCB) for patients with rectal and perirectal le-sions …