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


OAK BROOK, Ill. 12 july 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.
Large Sessile Adenomas Are Associated 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.
Preoperative Detection of Familial Pancreatic Neoplasms by Endoscopic Ultrasonography (EUS), Multidetector Computed Tomography (CT) and/or Magnetic Resonance Cholangiopancreatography (MRCP)
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.
Peroral Cholangioscopy Guided Stone Therapy ¡§C Report of an International Multicenter Registry
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: Blood Test May Replace Biopsy In Fatty Liver Diagnosis

When fatty liver is the problem, a simple blood test can determine as well as an hepatic biopsy whether the condition is dangerous or benign, a researcher said here. In a large cohort study, the blood test -- for a marker of liver cell death -- was highly accurate in distinguishing non-alcoholic steatohepatitis (NASH) from other forms of fatty liver and from healthy livers, found Ariel Feldstein, M.D., of the Cleveland Clinic.
The test looks for fragments of cytokeratin-18, a liver filament protein that is broken down specifically during liver cell death, Dr. Feldstein told a session at Digestive Disease Week.
The level of cytokeratin-18 fragments is significantly elevated (P<0.001) in patients with NASH, compared with those who have simple steatosis or a healthy liver, Dr. Feldstein said.
He and colleagues had previously shown that cell death plays a role in NASH, but not in patients with simple steatotis, which is regarded as a benign condition that does not progress.
To follow up, they enrolled 178 patients (participants in several fatty liver clinical trials) whose condition was well characterized by biopsy. Also, they enrolled 150 age-matched healthy controls.
Using a monoclonal antibody to cytokeratin-18 fragments, they found that the plasma level of the fragments predicted the likelihood of having NASH, as opposed to simple steatosis.
Specifically, every increase of 50 U/L increased the likelihood of NASH (opposed to steatosis) by 74%, which was significant at P=0.0001. The odds ratio was 1.74, with a 95% confidence interval from 1.31 to 2.31.
Among patients with any form of fatty liver, the plasma level of the fragments ranged from 68 to 3000 U/L, with a median of 244. Patients with benign fatty liver had a median of 182 and those with borderline disease had a level of 179. The healthy controls had a median level of 145 U/L.
By contrast, those with NASH had a median level of 361, Dr. Feldstein said.
If the cutoff for NASH is set at 246 U/L, he said, the test predicts the disease with a specificity of 81% and a sensitivity of 75%.
The test for the cytokeratin-18 fragments is commercially available, Dr. Feldstein said, but only as a research tool, and it's not likely to be available for clinical use for a couple of years.
The test is "certainly farther along than other biomarkers we've seen for liver disease," commented Jacquelyn Maher, M.D., of the University of California San Francisco.
But "there are still some bugs to be worked out," said Dr. Maher, who was not involved in the research. Specifically, she said, "there's not a lot of wiggle room" between those with frank NASH and those with borderline disease, which may limit diagnostic utility.