title: Utility of an upper echoendoscope for endoscopic ultrasonography of malignant and benign conditions of the sigmoid/left colon and the rectum.
abstract: OBJECTIVE
  The majority of data on colonic endoscopic ultrasound (EUS) are limited to malignant lesions in the rectum and diseases of the anal sphincter. The forward-oblique-viewing upper echoendoscope has been mostly applied for staging rectal cancer. A front-viewing echocolonoscope is available but has not been widely used because of limited indications and the expense of buying another instrument. The purpose of our study was to evaluate the utility of a forward-oblique-viewing upper echoendoscope for EUS of malignant and benign lesions of the sigmoid/left colon and the rectum.
  
  
  METHODS
  Thirty-two EUS exams were performed for a variety of indications in the rectum and the sigmoid/left colon. The patients were prepared for the exam in a manner similar to the performance of flexible sigmoidoscopy. Flexible sigmoidoscopy was performed in all cases before performing EUS. Surgical path data were reviewed in all cases if the patient had surgery after EUS.
  
  
  RESULTS
  Twenty-six exams were done for staging of rectosigmoid carcinoma, follow-up after chemotherapy and/or radiation, or to look for recurrence after resection of colorectal cancer. Surgical pathology results were available in 20 patients. The accuracies of EUS were 85% for T staging and 80% for N staging. Six EUS exams were for benign causes, including evaluation for the presence of a perirectal abscess in two (no abscess found), to rule out rectal varices in one (EUS confirmed rectal varices), and evaluation of submucosal lesions. One patient subsequent to EUS imaging also underwent a linear EUS-guided fine-needle aspiration of a submucosal mass in the rectum with the fine-needle aspirate consistent with a myogenic tumor.
  
  
  CONCLUSIONS
  The forward-oblique-viewing upper echoendoscope is a versatile instrument that can be applied for EUS imaging of malignant and benign indications not only in the rectum but also in the sigmoid/left colon.
authors.affiliation: Program for Endoscopic Ultrasound, Veterans Affairs Medical Center and Wright State University, Dayton, Ohio, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Bhutani
authors.forename: P
authors.initials: P
authors.lastname: Nadella
mesh_terms: D003106:Colon / Q000000981:diagnostic imaging* / Q000473:pathology; D012809:Colon, Sigmoid / Q000000981:diagnostic imaging; D003108:Colonic Diseases / Q000000981:diagnostic imaging*; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging; D019723:Endoscopes / Q000592:standards*; D019160:Endosonography / Q000295:instrumentation*; D006801:Humans; D009367:Neoplasm Staging / Q000379:methods; D012002:Rectal Diseases / Q000000981:diagnostic imaging*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging; D012007:Rectum / Q000000981:diagnostic imaging* / Q000473:pathology