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Background The extrahepatic portal vein is inaccessible to direct catheterization. Methods Because EUS can readily image the portal vein, the feasibility of EUS-guided portal vein catheterization by using a 22-gauge needle was studied in 7 normal pigs and 14 pigs in which portal hypertension was induced (7/14 anticoagulated). Results Catheterization was not possible by EUS or transhepatic methods in, respectively, 3 and 5 animals. One anticoagulated animal had a small amount of periduodenal bleeding as a result of EUS catheterization. The mean normal portal vein pressure (1 standard deviation) as determined by EUS and transhepatic methods was, respectively, 20.3 (4) mm Hg and 20.4 (2) mm Hg. Injection of polyvinyl alcohol particles increased the portal vein pressure by 10.2 (11.59) mm Hg. There was a close correlation under all conditions between the mean portal vein pressures obtained by EUS and transhepatic catheterization (r=0.91). Conclusions EUS-guided portal vein catheterization appears to be feasible in an animal model and provides accurate pressure measurements.

Background Photodynamic therapy of pancreatic cancer by using percutaneously placed light catheters has been reported. The feasibility and safety of EUS-guided photodynamic therapy of the pancreas was studied in a porcine model. Methods After injection of porfimer sodium, a 19-gauge needle was inserted into the pancreas, the liver, the spleen, and the kidney under EUS guidance. A small diameter quartz optical fiber was passed through the EUS needle and used to illuminate the tissue with laser light. The tissue response to photodynamic therapy was examined. Results Localized tissue necrosis was achieved in all organs, without significant complication. There was no significant difference in inflammation induced by photodynamic therapy within the various organs. Conclusions EUS-guided photodynamic therapy is a safe and simple technique that can induce small areas of focal tissue ablation within the liver, the pancreas, the kidney, and the spleen, and potentially could be used to treat a variety of benign and malignant conditions.

Percutaneous cementoplasty (PC) consists of injecting acrylic cement (polymethylmethacrylate) in bone and is a perfect example of a minimally invasive technique in the musculoskeletal system. PC has been performed since 1984. Its role is to consolidate weight-bearing bone and to treat pain. Bone packing with acrylic cement is a procedure aimed at preventing pathological fractures and pain in patients with vertebral body lesions and acetabular metastasis.

Percutaneous radiological techniques are useful in the assessment and therapy of jaundiced patients. After initial evaluation using noninvasive methods such as ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), or radionuclide imaging, most patients with evidence of biliary obstruction require direct cholangiography by percutaneous transhepatic cholangiography (PTC) or endoscopic retrograde cholangiography (ERC) to establish the underlying cause. With either technique, once a diagnosis of biliary obstruction and its cause has been established, the obstruction can be relieved during the same procedure. The choice between percutaneous and endoscopic cholangiography usually depends to a large extent on local availability. In most institutions, ERC is the modality first used. PTC is performed when endoscopic expertise is unavailable, or when ERC is unsuccessful. PTC is also useful when the biliary tree is insufficiently demonstrated by ERC, which commonly occurs with obstruction at the liver hilum (Ferrucci et al. 1980; Cowling and Adam 2001). MR cholangiography is emerging as an excellent noninvasive test for the initial evaluation of patients with biliary obstruction. In a few centers, MRI has replaced direct methods of cholangiography in the investigation of biliary obstruction (Little et al. 1999; Funaki et al. 2000; Soto et al. 2000; Pavone et al. 1999).

Thrombosis of the portal venous system (PVS) may complicate cirrhosis, pancreatitis, malignancies, and hypercoagulable states. Computed tomography (CT) scanning can diagnose thrombi present in the lumen of the PVS, but is probably insensitive. Endoscopic ultrasound (EUS) may be a more sensitive test for diagnosing PVS thrombosis (PVST). We sought to determine the accuracy of EUS for the diagnosis of PVST.Using a retrospective analysis of patients' studies retrieved from a database at Massachusetts General Hospital, we determined the sensitivity and specificity of EUS in 16 patients with PVST and 29 without PVST as proven by surgery and/or CT scanning. All patients underwent a linear EUS exam of the PVS and the results of the EUS report were used as the basis of the study.The sensitivity of EUS for the finding of PVST was 81% in 13 of 16 patients and the specificity was 93% in 27 of 29 patients with an overall accuracy of 89% (40/45). In an additional group of 11 patients, EUS demonstrated the presence of a PVST that was not detected by CT scanning.Linear EUS is a highly sensitive and specific test for PVST.

Endoscopic mucosal resection of gastric neoplasms is a curative technique that avoids surgery and its potential complications. Infrequently performed in the West, the limitations, pitfalls and challenges provided by this new therapeutic modality are not well known by general surgical pathologists. We evaluated a series of 39 endoscopic mucosal resections and assessed the correlation between original biopsies and final diagnoses, depth of excision, status of deep and lateral margins, artifactual changes and recurrence rate. The tumors consisted of 24 intramucosal carcinomas, six high-grade dysplasias, eight low-grade dysplasias and one submucosal invasive carcinoma. The preresection diagnoses corresponded to the final evaluation in 63% of the cases with previous biopsies. In 37% of the cases, the biopsies under-diagnosed the neoplasia. The rate of positive margins was 38%. Iatrogenic changes, that is, intramucosal hemorrhage and electrodiathermic burn, were noted in 44% of the cases but hindered the pathologic evaluation in only 10% of the cases. Persistence or recurrence was observed in only seven cases and there was no progression to advanced adenocarcinoma. Based on our experience, we offer some recommendations in order to provide optimal pathologic analysis of endoscopic mucosal resection specimens.

Endoscopic ultrasound (EUS) is widely used in the evaluation of various pancreatic diseases including pancreatic cystic lesions (PCLs). EUS-guided fine-needle aspiration (EUS-FNA) of PCLs provides cyst fluid, which is used for the differentiation of PCLs. EUS-FNA of PCLs is a safe procedure with a low complication rate. Contrary to the concerns expressed by some investigators, preoperative EUS-FNA of mucinous PCLs is unlikely to increase the frequency of postoperative peritoneal seeding.

Background. Cystic tumors of the pancreas are composed of benign, premalignant, malignant, and inflammatory lesions that are traditionally difficult to diagnose. Most of the tumors are initially detected on CT/US scanning, but often the morphological characteristics are insufficient for making a definitive diagnosis. Endoscopic ultrasound (EUS) may be an ideal tool for imaging of these lesions because it can provide highly detailed imaging without interference by bowel or air. Furthermore, EUS can direct fine needle aspiration of the lesions, providing cyst fluid for cytologic examination. The findings of cyst fluid cytology can be complemented by the use of cyst fluid tumor makers such as CEA. Using the morphologic appearance by endosonography, the results of cytology, and tumor marker analysis, EUS can often differentiate between benign, malignant, and inflammatory cystic lesions of the pancreas.

Endoscopic ultrasound (EUS) is an ideal imaging technique for pancreatic cystic lesions. Ultrasound is exquisitely sensitive for detecting and characterizing cysts arising in solid organs, and when the transducer is placed on an endoscope, high resolution imaging of the pancreas is achieved. Linear EUS can also guide needle aspiration of pancreatic cystic lesions and through the use of aspiration cytology, cystic tumors of the pancreas can be diagnosed. Since cytology is a relatively insensitive test, cyst fluid tumor markers such as CEA have been employed to improve the sensitivity for the detection of malignancy. Cyst fluid CEA values are uniformly low in serous cystadenomas, higher in mucinous lesions, and markedly elevated in mucinous cystadenocarcinomas. Through the use of these techniques, the ability to detect and diagnose early malignancies of the pancreas will be greatly enhanced.

We present a new method for generating micron-scale OCT images of interstitial tissue with a hand scanning probe and a linear optical encoder that senses probe movement relative to a fixed reference point, i.e., tissue surface. Based on this approach, we demonstrate high resolution optical imaging of biological tissues through a very long biopsy needle. Minor artifacts caused by tissue noncompliance are corrected using a software algorithm which detects the simple repetition of the adjacent A-scans. This hand-scanning OCT imaging approach offers the physician the freedom to access imaging sites of interest repeatedly.

invasive carcinoma. A median time to recurrence after resection was 31 months (range 183) for non-invasive tumors and 11 months (range 1-145) for those with invasion (P=0.05). No clinical or pathological predictors of recurrence were found for non-invasive IPMNs. Among invasive tumors, predictors for recurrence were macroscopic invasion (P=0.003), N1 status (P

This is one of a series of statements discussing the utilization of gastrointestinal endoscopy in common clinical situations. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for the appropriate use of endoscopy are based on a critical review of the available data and expert consensus. Controlled clinical studies are needed to clarify aspects of this statement and revision may be necessary as new data appear. Clinical considerations may justify a course of action at variance from these recommendations.

Dramatic improvements in the quality of instrumentation have established endoscopy as the primary method for diagnosing and treating many pancreatic and biliary diseases. Endoscopic retrograde cholangiopancreatography (ERCP) is the most commonly used procedure in pancreatic–biliary endoscopy. Through its use of detailed endoscopic and fluoroscopic images, ERCP has evolved into a predominantly therapeutic technique. A new endoscopic procedure, endoscopic ultrasonography, provides high-resolution ultrasound images of the pancreas and biliary ducts and complements the findings of ERCP. With continued improvements in instrumentation, small-diameter catheters will permit even better imaging of the ductal systems with high-resolution endoscopy and ultrasonography. Instrumentation The duodenoscopes used . . .

The ability to image the gastrointestinal (GI) tract with endoscopically placed ultrasound transducers represents a major advance in endoscopic imaging. Although the original instruments were designed to examine areas of the upper GI tract not seen with transabdominal ultrasonography, the effectiveness of endoscopic ultrasonography (EUS) has recently been demonstrated for a variety of upper GI disorders. The role of EUS has been expanded with the introduction of EUS-guided fine-needle aspiration (FNA) of mural, extramural, and pancreatic lesions. This technique has also been used for several therapeutic applications.

Intraductal papillary mucinous neoplasm (IPMN) consists of four epithelial subtypes that correlate with histological grades and risks for malignant transformation. mAb Das-1 is a monoclonal antibody against a colonic epithelial phenotype that is reactive to premalignant conditions of the upper GI tract. We sought to assess the ability of mAb Das-1 to identify IPMN with high risk of malignant transformation.mAb Das-1 reactivity was evaluated in 94 patients with IPMNs by immunohistochemistry. Lesional fluid from 38 separate patients with IPMN (n=27), low-grade non-mucinous cystic neoplasms (n=7) and pseudocysts (n=4) was analysed by ELISA and western blot.Immunohistochemistry-Normal pancreatic ducts were non-reactive and low-grade gastric-type IPMN (IPMN-G) (1/17) and intermediate-grade IPMN-G (1/23) were minimally reactive with mAb Das-1. In contrast, mAb Das-1 reactivity was significantly higher in high-risk/malignant lesions (p0.0001) including: intestinal-type IPMN with intermediate-grade dysplasia (9/10); high-grade dysplasia of gastric (4/7), intestinal (12/12), oncocytic (2/2) and pancreatobiliary types (2/2); and invasive tubular (8/12), colloid (7/7) and oncocytic (2/2) carcinoma. The sensitivity and specificity of mAb Das-1 for high-risk/malignant IPMNs were 85% and 95%, respectively. Lesional fluid-Samples from low- and intermediate-grade IPMN-G (n=9), and other low-grade/benign non-mucinous lesions demonstrated little reactivity with mAb Das-1. Conversely, cyst fluid from high-risk/malignant IPMNs (n=18) expressed significantly higher reactivity (p0.0001). The sensitivity and specificity of mAbDas-1 in detecting high-risk/malignant IPMNs were 89% and 100%, respectively.mAb Das-1 reacts with high specificity to tissue and cyst fluid from high-risk/malignant IPMNs and thus may help in preoperative clinical risk stratification.

Introduction The five year survival for pancreatic ductal adenocarcinoma (PDAC) is less than 5% in spite of the advances in management of cancers in the last few decades. Even though surgical resection remains the only potentially curative treatment for PDAC, only 10–20% of patients are candidates for pancreatic resection with almost 50% of patients having distant spread of tumour and approximately one-third manifesting locally advanced disease. Kahaleh and colleagues have demonstrated that EUS guided RF ablation (EUS-RFA) of the pancreatic head using Habib EUS-RFA catheter (Emcision Ltd, UK) was well tolerated in 5 Yucatan pigs and with minimal pancreatitis (1). The aim of this report is to outline the feasibility, safety, complications and early results of EUS-RFA using Habib catheter in patients with inoperable PDAC. Methods Seven patients underwent EUS-RFA of PDAC. A novel monopolar radiofrequency (RF) catheter (1.2 mm Habib EUS-RFA catheter, Emcision Ltd, London) was placed through a 19 or 22 gauge fine needle aspiration (FNA) needle after FNA was performed. Results Seven patients had EUS-RFA of PDAC with a median age of 69 (range 50 – 77) years. There were 3 female and 4 male patients. Five patients had PDAC in the head of pancreas whilst two had in the body of pancreas. RF was applied at 5 watts, 10 watts and 15 watts in an incremental manner in 1, 3 and 3 patients respectively. The median number of applications were 3 (range 2 – 4) and each application was 90 seconds. The EUS-RFA was completed in all patients. The mean size was 35.2mm and the post procedure imaging in 3–6 months showed decrease in size of the lesion in two patients, whilst the lesions were unchanged in the rest of the patients. There were no early complications like injury or perforation of duodenal or gastric wall, bleeding or severe pancreatitis. All patients stayed overnight after the procedure for observation and four were discharged next day and there were no readmissions post procedure due to pain. One patient had mild pancreatitis which settled with conservative management and was discharged 3 days post procedure. Conclusion EUS- RFA of PDAC with a novel monopolar RF probe was well tolerated in 7 patients. The initial results suggest that the procedure is technically relatively easy and safe Disclosure of Interest M. Pai: None Declared, J. Yang: None Declared, X. Zhang: None Declared, Z. Jin: None Declared, D. Wang: None Declared, H. Senturk: None Declared, S. Lakhtakia: None Declared, D. N. Reddy: None Declared, M. Kahaleh: None Declared, N. Habib Shareholder of: EMcision Limited, London, United Kingdom, Conflict with: Director, EMcision Limited, London, United Kingdom, W. Brugge: None Declared. Reference Gaidhane M et.al . Endoscopic Ultrasound-Guided Radiofrequency Ablation (EUS-RFA) of the Pancreas in a Porcine Model. Gastroenterol Res Pract. 2012; 431451.

Sa1440 Presence of Metal Stent in Porcine Bile Duct Attenuates the Effect of Radiofrequency Ablation: Results of a Pilot Study Won Jae Yoon*, Ebubekir S. Daglilar, Mari Mino-Kenudson, William R. Brugge Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA; Pathology, Massachusetts General Hospital, Boston, MA Background: Endoscopically applied biliary radiofrequency ablation (RFA) in patients with unresectable malignant biliary stenosis has shown promising results. RFA may re-establish patency of occluded metal biliary stents. We have shown that application of RFA at 10 W for 90 seconds in the porcine bile duct results in transmural tissue ablation. However, there is little data on RFA in the bile duct containing a metal stent. Aims: The aims of this study were to determine the feasibility and performance characteristics of biliary RFA in the stented porcine bile duct. Methods: Four farm pigs weighing 40-50 kg were used for this study. Under general anesthesia and a laparotomy, a duodenotomy was performed. After identification of the bile duct opening, a 10-mm X 6-cm uncovered metal biliary stent (Zilver® stent, Cook Medical, Winston-Salem, NC) was deployed in 3 pigs; the stent was not deployed in 1 pig, serving as a control. The biliary bipolar RFA catheter (HabibTM EndoHPB catheter, EMcision Ltd., London, UK) was introduced through the stent lumen or the bile duct lumen. In the stented bile duct, RFA was applied at 10 W for 90 seconds, with a range of voltages among pigs (66 V [n 1], 132 V [n 1], and 190 V [n 1]). In the control bile duct (n 1), RFA was applied at 10 W and 190 V for 90 seconds. After the RFA, the pigs were euthanized and necropsied. The bile duct was examined for histological changes. Results: The retrograde insertion of the biliary RFA catheter through the metal stent or the bile duct orifice was easily achieved. Grossly, the ablated area was distributed only along the area adjacent to the electrodes of the RFA probe. In the unstented bile duct, RFA resulted in transmural ablation of the bile duct wall (Figure 1A). However, in the stented bile duct, the depth of ablation was reduced compared to the unstented bile duct. In detail, at 66 V (Figure 1B) and 132 V (Figure 1C), the ablation was limited to the superficial mucosa with no effect on the glands. At 190 V (Figure 1D), the ablation of the superficial mucosa including the superficial glands was noted. Conclusions: Biliary RFA through a metal stent seems technically feasible. However, at 10 W, biliary RFA was markedly attenuated by the presence of a metal stent. A greater power is probably needed to achieve deep ablation.

Background: Endoscopic treatment by either radiofrequency (RFA) ablation or endoscopic mucosal resection (EMR) has become first line treatment for Barrett's esophagus (BE) with high grade dysplasia, while focal EMR and subsequent elimination of the residual segment by RFA or EMR is accepted therapy for intramucosal cancer (IMC). RFA and EMR are known to be clinically effective but the effect on the mRNA expression of molecular markers of disease stage, which may inform the long term risk of progression to adenocarcinoma, is unknown. We compared the mRNA expression profile in pre-treatment BE tissues biopsies and post-treatment neo-squamous tissues from the same level to provide a surrogatemolecular estimate of treatment effect. Methods: Paired pre-treatment BE tissues and post-treatment neosquamous biopsies were obtained from 38 patients treated by RFA (20 patients (3 IMC (prior EMR), 5 HGD, 12 LGD) or EMR (18 patients, 6 IMC, 12 HGD). mRNA expression of 16 genes significantly associated with different BE stages was measured using a multiplex tandem RT-PCR method with preand post-treatment tissues assessed simultaneously. Distal esophageal tissues from 12 patients with no history of GERD or BE were used as normal controls. Results: Endoscopic therapy resulted in a highly significant change in median values towards the normal squamous mucosa expression profile for all 16 genes on unpaired analysis. This change remained significant for 12 genes by paired analysis (t test). The only significant treatment differences in pre-post mean difference in gene expression were greater changes for RFA compared to EMR for 5 genes. The neosquamous expression profile was significantly different to the normal control profile for 9 of 16 genes. Conclusions: Both RFA and EMR result in marked changes in mRNA expression, with replacement of the highly disordered Barrett's dysplasia or IMC expression profile with a more "normal" expression profile. The neosquamous mucosa was significantly different to the normal control squamous mucosa for most genes but the significance of this finding is uncertain and may reflect confounding factors.

INTRODUCTION: Chronic Atrophic Gastritis (CAG) is the most important independent risk condition for gastric cancer, histology being considered the gold standard for both diagnosis and follow up. The Operative Link for Gastritis Assessment (OLGA) is an innovative histological system proposed for staging atrophic gastritis in a prognostic view. GastroPanel (Biohit, Helsinki, Finland) is a serological kit for a non-invasive diagnosis of chronic atrophic gastritis (CAG), including serum pepsinogen I (PGI), pepsinogen II (PGII), gastrin-17 (G17) and IgG anti-Helicobacter pylori antibodies (IgG-Hp). Clinical practice is lacking of a non invasive instrument useful to predict and to follow the stage of atrophic gastritis. AIMS& METHODS: To evaluate correlation between GastroPanel and OLGA stage, in a cohort of dyspeptic patients referred from a primary care setting to our G.I. Unit Histological evaluation of gastric biopsies was performed in 125 pts (83 females, mean age 53 yrs). Atrophy was assessed according to the OLGA staging system. OLGA stages III and IV are considered at high risk for gastric cancer development. From each subject, a blood sample was taken for GastroPanel analysis. RESULTS: GastroPanel analysis showed that 79 pts (63,2%) have no gastritis, 22 pts (17,6%) a Hp-related chronic gastritis and 24 (19,2%) atrophic gastritis picture. Comparing GastroPanel results to the histological findings, 48 pts of the first group were confirmed normal at histology, 27 pts have an OLGA stage 0-II, 4 pts have an OLGA stage III, none stage IV. Among the patients with Hp-related gastritis, 1 pt results normal at the histological evaluation, 20 pts have an OLGA stage 0-II, 1 pt has an OLGA stage III; 6 out of the 24 pts with evidence of CAG at GastroPanel have an OLGA stage 0-II, 18 pts have an OLGA stage III-IV. The negative predictive value (NPV) of GastroPanel for CAG is 95,0%, being the positive predictive value (PPV) 75,0%. CONCLUSION: GastroPanel shows an high NPV to predict absence of atrophic gastritis. The relationship beetween GastroPanel and OLGA system seems to confirm the clinical performances of the test

s / Pancreatology 13 (2013) e1–e94 e87 postoperative parameters were equal to the patients without gastrectomy. The accumulation of knowledge and skill will needed for the improvement of surgical outcome.

Endoscopic sonography is a new approach to visualizing upper gastrointestinal lesions. The sonographic device, which incorporates a sonographic transducer mounted on a standard fiberoptic endoscope, makes it possible to obtain high-resolution images of mucosal and mural lesions of the gastrointestinal tract, as well as of adjacent masses. This technique has substantially improved preoperative staging of esophageal and gastric cancers. In addition, high-resolution sonographs of the pancreas can be obtained without degradation by overlying bowel gas, making identification of small, previously occult lesions of the pancreatic head possible. We have used endoscopic sonography in staging esophageal, gastric, and pancreatic cancers in more than 200 patients. This essay illustrates our experience with this new technique.