Digestive Disease Week study examined ACR's guidelines for CT colonography interpretation

OAK BROOK, Ill. ¡§C JULY 11, 2008 -- A study presented at Digestive Disease Week® 2008 examined the American College of Radiology's (ACR) CT colonography guidelines recommending that polyps ≤ 5mm in size not be reported on CT colonography by applying them to an endoscopic database that collected information about polyps that had been removed and processed. The guidelines also recommend that patients with one or two polyps 6 to 9 mm in size and no larger polyps can have repeat CT colonography in three years rather than prompt polypectomy. The database included information for 10,780 polyps removed from 5,079 patients (among 10,034 colonoscopies) over a five-year interval. Overall, the study determined that if CT colonography rather than colonoscopy had been used in this population, and assuming 100 percent sensitivity of CT colonography for polyps ≥ 6 mm and ACR interpretation recommendations, then 29 percent of all patients and 30 percent of patients over age 50 with high risk adenoma findings would have been interpreted as normal. High risk adenoma findings were defined according to current post-polypectomy surveillance guidelines as any adenoma 1 cm or larger in size, any adenoma with high grade dysplasia or villous elements, or patients with three or more adenomas of any size. An additional 18 percent of both groups could have had polypectomy delayed for at least three years.

The study, "American College of Radiology (ACR) Recommendations for CT Colonography (CTC) Interpretation: Implications for Resection of High Risk Adenoma Findings," was presented by Douglas K. Rex, MD, FASGE, chancellors professor of medicine, Indiana University School of Medicine and director of endoscopy at Indiana University Hospital, who also presented other research during DDW® on large sessile adenomas and their association with a high prevalence of synchronous neoplasia.

In this study, patients with large (≥ 2cm) sessile adenomas who undergo piecemeal endoscopic resection are recommended to have a follow up examination in three to six months to examine the polypectomy site for residual disease. The study was a retrospective single academic center review of synchronous neoplastic findings in 190 consecutive patients with intact colons and single large sessile adenomas resected endoscopically. All included patients had at least one full colonoscopy. Synchronous polyps were those removed at the same colonoscopy that discovered the large sessile adenoma, or at any follow up endoscopic examination within 12 months of discovery of the large sessile adenoma.

Researchers found that 75 percent of patients had at least one synchronous adenoma, and the 190 patients had an average of four synchronous adenomas. Thirty percent of patients had at least one synchronous advanced adenoma (adenoma ≥1 cm in size, or with high grade dysplasia or villous element), and three percent had synchronous lesions with high-grade dysplasia. Synchronous disease was distributed throughout the colon and was likely to be in a distant colonic segment as in the same or an adjacent colonic segment. Researchers concluded that patients with large sessile adenomas resected endoscopically warrant follow up not only to ensure complete resection, but also to ensure clearing of the entire colon.

Research by Marcia I. Canto, MD, FASGE, associate professor of medicine and oncology, Johns Hopkins University, Baltimore, MD, was presented on the preoperative detection of familial pancreatic neoplasms. Lives can be saved if high grade dysplasia and early familial ductal adenocarcinoma can be detected in high risk individuals before these lesions progress to advanced disease. Researchers looked to characterize pancreatic neoplastic lesions detected by imaging tests in high risk individuals; to compare the diagnostic yield and incremental benefit of EUS over CT/MRCP; and to determine the incremental benefit of fine needle aspiration (FNA) over EUS alone.

Data prospectively collected from 1998-2007 from two screening studies and the center's clinical screening program were analyzed. High risk individuals with Peutz-Jeghers syndrome or first degree relatives from familial ductal adenocarcinoma kindreds with at least two affected, had either multi-detector CT and or MRI/MRCP, and EUS. Radiologic and EUS features of each preoperatively detected lesion were compared with the pathologic findings. The diagnostic yield of each imaging modality was calculated on a per lesion basis.

Of 165 patients who had EUS and CT/MRCP, 19 asymptomatic high risk individuals underwent partial resection (15), partial followed by completion pancreatectomy (3), or total pancreatectomy (1) for 44 pancreatic lesions (size range 2.6-21 mm) detected by EUS, CT or MRCP. Researchers concluded that most pancreatic neoplasms detected by screening tests are small and low grade, but six percent of intraductal papillary mucinous neoplasms < 3 cm may contain high grade dysplasia. EUS detects almost twice as many neoplastic lesions as CT/MRCP, regardless of size, and FNA adds little to EUS.

A study by Mansour A. Parsi, MD, department of gastroenterology at the Cleveland Clinic Foundation, examined peroral cholangioscopy used for the management of biliary stones that cannot be removed by conventional methods. The need for two expert operators and technical limitations of cholangioscopes has hampered its widespread adoption for the management of difficult to remove biliary stones. Researchers examined the SpyGlass Direct Visualization (SGDVS) system single operator peroral cholangioscope with four-way tip deflection that recently became commercially available. The aim of the study was to evaluate the efficacy and safety of the SGDVS for treatment of difficult to remove biliary stones and assess the utility of the device for detection of missed stones by endoscopic retrograde cholangiography (ERC).

Ninety-eight patients had cholangioscopy guided stone therapy using SGDVS. These patients reflect 33 percent of the cases in a multicenter open-label cholangioscopy registry involving 15 tertiary care centers in the US and Europe in which each patient undergoes ERC immediately followed by cholangioscopy. Procedural indications were bile duct stones not amenable to removal by conventional methods or missed by ERC. Procedural success was defined as the ability to adequately visualize and initiate stone therapy.

Stone location was 56 percent for the common bile duct (CBD), 22 percent for the common hepatic duct (CHD), seven percent for the intrahepatic ducts (IHD), ten percent for the cystic duct, gallbladder was one percent, and the left and right hepatic ducts (LHD and RHD) was four percent. In 59 percent of the cases, stones were impacted, and in 29 percent, stones were reported as missed during the ERC immediately preceding the cholangioscopy. Procedural success was 92 percent in the group as a whole.

DDW® is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. Jointly sponsored by the American Association for the Study of Liver Diseases, the American Gastroenterological Association (AGA) Institute, the American Society for Gastrointestinal Endoscopy and the Society for Surgery of the Alimentary Tract, DDW took place May 17-22, 2008, at the San Diego Convention Center, San Diego, Calif. The meeting showcased approximately 5,000 abstracts and hundreds of lectures on the latest advances in GI research, medicine and technology. For more information, visit www.ddw.org.

Founded in 1941, the mission of the American Society for Gastrointestinal Endoscopy is to be the leader in advancing patient care and digestive health by promoting excellence in gastrointestinal endoscopy. ASGE, with more than 10,000 physician members worldwide, promotes the highest standards for endoscopic training and practice, fosters endoscopic research, recognizes distinguished contributions to endoscopy, and is the foremost resource for endoscopic education. Visit www.asge.org and www.screen4coloncancer.org for more information.

Endoscopy is performed by specially-trained physicians called endoscopists using the most current technology to diagnose and treat diseases of the gastrointestinal tract. Using flexible, thin tubes called endoscopes, endoscopists are able to access the human digestive tract without incisions via natural orifices. Endoscopes are designed with high-intensity lighting and fitted with precision devices that allow viewing and treatment of the gastrointestinal system. In many cases, screening or treatment of conditions can be delivered via the endoscope without the need for further sedation, treatment or hospital stay.