indeterminate cystic lesions that required EUS fine-needle aspiration. Afteraspiration of cyst fluid, lavage was done for 3-5 minute with 80% ethanol andfluid was totally aspirated after lavage. The carcinoembryonic antigen (CEA) andamylase levels were checked with initial cyst fluid. All patients were followed upfor more than 3 months and thirty patients followed up for more than 12months. Results: The mean diameter of the cysts was 29.1mm (range, 20-50mm)and twenty five cysts were oligolocular cysts. The cysts were located in thehead/uncinate of the pancreas in 10 patients (27.0%), the body in 16 patients(43.2%) and the tail in 11 patients (29.7%). The median levels of CEA andamylase were 8.6 ng/mL (range, 0.5-18510 ng/mL) and 300 U/L (range, 1.0-503599.0 U/L) respectively. After the procedure three patients had fever withoutdocumented bacteremia, 6 patients had mild abdominal pains, and only 2patients had mild pancreatitis. The mean follow-up period was 25.4 months.Presumed diagnoses of pancreatic cysts were made with reference to cyst fluidCEA and amylase levels. Serous cystadenoma (SCA) was diagnosed if the CEAlevel was less than 5 ng/mL and the amylase level was less than 800 U/L,pseudocyst was diagnosed if the CEA level was less than 5 ng/mL and theamylase level was greater than 800 U/L. Cyst fluid CEA level of more than 200ng/mL was further classified as an mucinous cystic neoplasm (MCN) orintraductal papillary mucinous neoplasm (IPMN), when the amylase level wasless than 800 U/L or more than 800 U/L. The pancreatic cysts that did not meetthese criteria were classified as indeterminate cysts. Presumed diagnoses wereMCN in 2 patients, IPMN in 2 patients, pseudocyst in 2 patients, SCA in 10patients and indeterminate cyst in 21 patients. Among 30 patients with 1 yearfollow up, complete response was observed in 12 patients (40%), a partialresponse in 4 patients, and persistent cysts in 14 patients after 12 months. Onepatient had complete resolution after 3 months but the cyst recurred after oneyear. Two patients with persistent cysts underwent surgery. Presumed diagnosisof the resected cysts was indeterminate cyst, and final diagnosis was IPMN andMCN. Conclusions: EUS-guided ethanol lavage appears to be a safe method fortreating incidental pancreatic cysts and 40% of patients had complete resolutionafter 12 months.

280Long-Term Follow-Up of Indeterminant Pancreatic CystsInitially Examined by Endoscopic UltrasoundJayaprakash Sreenarasimhaiah*, Pragathi Kandunoori, Amil Patel,Deepak AgrawalMedicine/Gastroenterology, University of Texas Southwestern MedicalCenter, Dallas, TXBackground: Endoscopic ultrasound (EUS) offers detailed evaluation ofpancreatic cysts as well as fluid analysis. Cysts of the pancreas are commonlyclassified as mucinous, cystic adenocarcinoma, serous or pseudocysts. However,despite examination, some cysts are deemed as indeterminate type. Aim:Determine if long-term clinical follow-up of indeterminate pancreatic cysts willreveal clinical or radiographic changes and possibly yield to a diagnosis.Methods: This retrospective study examined the pancreatic cyst data basebetween 2005 and 2008 with chart review for clinical follow-up until 2011.Patient demographics, radiographic and EUS imaging, cyst fluid analysis, andsurgical pathology were examined. Fluid CEA levels exceeding 192ng/mL alongwith aspirate cytology were used in the diagnosis of mucinous-type cysts.Results: Of 121 pancreatic cysts examined by EUS between 2005 - 2008, 49 (40%)were classified as indeterminate. This group included 21 men and 28 womenwith a mean age of 63.7 years. Mean size was 5.98 cm2 based on two-dimensional measurement of the area of the cyst. Six patients were lost tofollow-up. Of 43 patients, 10 (23 %) underwent surgical resection. Distalpancreatectomy was performed in 3 patients with final pathology revealingmucinous cysts. Pancreaticoduodenectomy was performed in 7 patients forpancreas head or uncinate process cysts with final pathology of IPMN (n�1),cystic adenocarcinoma (n�1) and benign pathology (n�7). In 3 patients (7%),follow-up computerized tomography (CT) imaging after at least one year showedcomplete resolution and suggested that these may have originally beenpseudocysts. Six patients died of unrelated disease. Of the remaining 30 patients,only one progressed after three years into a malignant neuroendocrine tumor ofthe pancreas tail. CT follow-up was available in 17 patients and demonstratedthat 4/17 cysts increased in size by �50% from a baseline average of 2.62cm2over a mean of 4 years (range of 2 - 5 years). The other 13 patients had stable orsmaller cysts with a baseline average size of 2.42cm2 which was similar to thosecysts that increased in size. In 7 patients, CT imaging suggested possible side-branch type IPMN with the development of multiple small cysts along the mainpancreatic duct. Conclusion: The majority of pancreatic cysts of indeterminatetype do not progress in size or pathology within five years. Cyst size is similar atbaseline between those that remain stable and those that progress. While distalpancreatic resection is less invasive and may help identify pathology,pancreaticoduodenectomy should be carefully considered given the lowlikelihood of malignancy. Careful routine surveillance with either CT or EUS mayhelp identify which cysts will progress in size or pathology.

281Quantitative Perfusion Analysis of Contrast-Enhanced HarmonicEndoscopic Ultrasonography in Solid Lesions of the PancreasMitsuharu Fukasawa*, Shinichi Takano, Makoto Kadokura,Ei Takahashi, Tadashi Sato, Nobuyuki EnomotoGastroenterology, University of Yamanashi, Yamanashi, JapanBackground and Aims: Distinguishing pancreatic adenocarcinoma from otherpancreatic masses still remains challenging with current imaging techniques.Recently developed contrast-enhanced harmonic endscopic ultrasonography(CEH-EUS) enables the real-time visualization of the perfusion patterns specificto different pancreatic lesions. However, its assessment is largely subjective andno objective criteria for diagnosis has not been established. This prospectivestudy aimed to evaluate the value of software-aided quantitative analysis of CEH-EUS for diagnosis of pancreatic solid lesions. Methods: A total of 94 patientspresenting with solid pancreatic lesions were prospectively enrolled. All patientshad conventional B mode and CEH-EUS with a second-generation contrast agent.Time-intensity curves (TIC) were obtained for all exams in 2 regions of interest(ROI) within the lesion and within the normal pancreatic tissue. Images wereprocessed using DAS-RS1 software; the following parameters were obtained:baseline intensity, maximum intensity, intensity at 1 minute, and time-to-peak.Absolute values and the ratio of the lesion to the normal tissue were evaluated.Result: Histological analysis revealed 55 pancreatic ductal adenocarcinomas(PDACs), 15 autoimmune pancreatitis (AIP), 11 chronic pancreatitis (CP), and 13pancreatic neuroendocrine tumors (PNETs). The peak ratio of the lesion to thenormal tissue was significantly lower in PDACs (0.60�0.24) and higher in PNETs(1.20�0.22) compared to AIP (0.97�0.13) and CP (0.96�0.04) (p � 0.01)(figure).When iso peak ratio range was set from 0.85 to 1.15, among PDACs 50 out of 55(91%) had low peak ratio (range 0.21-0.83). AIP and CP showed mostly iso peakratio (14/15 in AIP and 10/11 in CP). Among PNET 7 out of 13 (53%) had highpeak ratio (range 1.16-1.72) and 6 had iso peak ratio. The sensitivity, specificity,positive predictive value (PPV), and negative predictive value (NPV), andaccuracy of the low peak ratio for diagnosing PDAC were 91%, 95%, 96%, 88%,and 92%. Absolute values of intensity and time-dependent parameters were notsignificantly different among pancreatic disease. Conclusions: In most cases ofPDAC, CEH-EUS exhibits hypo-perfusion pattern compared to the adjacentnormal pacreatic tissue at capillary level that can be visualized using the smallmicrobubbles of ultrasound contrast agents, while AIP/CP with iso-perfusion andPNET with hyper-perfusion pattern. Contrast quantification software substantiatesthese subjective visual assessments, establishing the peak intensity ratio as thestatistically assured objective criteria to facilitate the differential diagnosis ofpancreatic solid lesions.

282PerOral Endoscopic Myotomy (POEM) for Esophageal Achalasia:205 Cases ReportPing-Hong Zhou*1, Liqing Yao1, Yi-Qun Zhang1, Ming-Yan Cai1,Yun-Shi Zhong1, Zhong Ren1, Mei-Dong Xu1, Wei-Feng Chen1,Quan-Lin Li1, Xin-Yu Qin2

1Endoscopy Center, Zhongshan Hospital, Fudan University, Shanghai,China; 2Department of General Surgery, Zhongshan Hospital, FudanUniversity, Shanghai, ChinaObjective: To evaluate the efficacy and the fesibility of peroral endoscopic

Abstracts

www.giejournal.org Volume 75, No. 4S : 2012 GASTROINTESTINAL ENDOSCOPY AB132