Br Stotland

EUS compared with CT, magnetic resonance imaging, and angiography and the influence of biliary stenting on staging accuracy of ampullary neoplasms

BACKGROUND Computerized tomography (CT), magnetic resonance imaging (MRI), and transabdominal ultrasound frequently fail to detect ampullary lesions. Endoscopic ultrasound (EUS) is a sensitive modality for detecting and staging ampullary tumors. Accurate staging may be affected by biliary stenting, which is frequently performed in these patients with obstructive jaundice. The present study assessed the accuracy of ampullary tumor staging with multiple imaging modalities in patients with and those without endobiliary stents. METHODS Fifty consecutive patients with ampullary neoplasms from two endosonography centers were preoperatively staged by EUS plus CT (37 patients), MRI (13 patients), or angiography (10 patients) over a 3(1/2) year period. Twenty-five of the 50 patients had a transpapillary endobiliary stent present at the time of endosonographic examination. Accuracy of EUS, CT, MRI, and angiography was assessed with the TNM classification system and compared with surgical-pathologic staging. The influence of an endobiliary stent present at the time of EUS on staging accuracy of EUS was also evaluated. RESULTS EUS was more accurate than CT and MRI in the overall assessment of the T stage of ampullary neoplasms (EUS 78%, CT 24%, MRI 46%). No significant difference in N stage accuracy was noted between the three imaging modalities (EUS 68%, CT 59%, MRI 77%). EUS T stage accuracy was reduced from 84% to 72% in the presence of a transpapillary endobiliary stent. This was most prominent in the understaging of T2/T3 carcinomas. CONCLUSIONS EUS is superior to CT and MRI in assessing T stage but not N stage of ampullary lesions. The presence of an endobiliary stent at EUS may result in underestimating the need for a Whipple resection because of tumor understaging.

Device choice and experience level in endoscopic foreign object retrieval: An in vivo study

BACKGROUND Successful foreign object retrieval may depend on device choice and the experience level of the endoscopist, although these factors have not been systematically evaluated. METHODS In anesthetized pigs, the ability to retrieve foreign objects (metal tack, button disc battery, wooden toothpick) placed endoscopically into the stomach was assessed. Seven university medical center gastroenterology attending physicians (5 clinical and 2 basic science research [BSR]), and 4 fellows-in-training participated. The devices used were the Roth retrieval net, rat tooth forceps, Dormia basket, polypectomy snare, and radial jaw forceps. The time to retrieve each object into an esophageal overtube within a 5 minute maximum was measured. RESULTS Only the Roth net and Dormia basket were successful in retrieving the button disc battery, although the Roth net was superior (100% vs 27%, Fisher p < 0.025). All devices were equally successful at retrieving the tack (82% to 100%, p = NS). The snare was significantly faster than the Roth net (p < 0.05). For the tack, there was significantly fewer difficulties encountered with the snare than the Roth net (Fisher p < 0.03). The Roth net was incapable of retrieving the toothpick; the other devices were equally successful (91% to 100%). The clinical attendings had a significantly higher success rate (95%) than the fellows (82%, chi squared p < 0.05) or combined fellows/BSR attendings (80%, p < 0.02), and were significantly faster than the fellows (p < 0.0002) or the fellows/BSR attendings (p < 0.0003). CONCLUSIONS The Roth net is the best device for retrieving smooth objects such as the button disc battery. For sharp objects, such as the tack and toothpick, best results were achieved with the snare, although the forceps were also effective. More experienced endoscopists had higher success rates and faster retrieval times. Both device choice and the experience level of the endoscopists have an impact on successful foreign object retrieval.

Preoperative and postoperative imaging for colorectal cancer.

Management and survival in colorectal cancer are dictated by the extent of the disease at the initial diagnosis. Technological advances over the past 25 years have improved the ability to accurately preoperatively stage these lesions and detect recurrence. This article reviews the focus on the utility of computerized tomography, magnetic resonance, endoscopic ultrasound, and newer imaging methods including PET scan and monoclonal antibodies in the management of colorectal carcinoma.