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Pancreatic cystic lesions are being detected with an increasing frequency. Endoscopic ultrasound (EUS) provides both diagnostic and therapeutic means for pancreatic cystic lesions. Detailed imaging and EUS-guided fine-needle aspiration provide additional information on pancreatic cystic lesions. EUS-guided pseudocyst drainage has advantages over conventional drainage modalities. EUS-guided cyst ablation is a promising therapeutic modality.

With the introduction of curvilinear endosonoscopes, endoscopic ultrasonography (EUS) has achieved the role of a therapeutic modality as well as diagnostic procedure. EUS-guided tumor ablation is one such therapeutic modality. Various techniques of EUS-guided tumor ablation have been described, including radiofrequency ablation, photodynamic therapy, laser ablation, and ethanol injection. Most of the currently described techniques are experimental. Development and continuous improvement of devices, as well as establishment of indications for EUS-guided tumor ablations, are mandatory., (Copyright © 2012. Published by Elsevier Inc.)

PCNs are composed of a wide range of lesions from benign cysts to malignancies . Although a cross-sectional imaging provides a sensitive screening test, EUS with FNA and cyst fluid analysis greatly increase the diagnostic certainty. Cyst fluid CEA offers the greatest accuracy in the differentiation between mucinous and nonmucinous PCNs. In the future, endoscopic ablation therapy might offer an alternative to the traditional surgical approach.

Objective: Invasive cancers arising from intraductal papillary mucinous neoplasm (IPMN) are recognised as a morphologically and biologically heterogeneous group of neoplasms. Less is known about the epithelial subtypes of the precursor IPMN from which these lesions arise. The authors investigate the clinicopathological characteristics and the impact on survival of both the invasive component and its background IPMN., Design and Patients: The study cohort comprised 61 patients with invasive IPMN (study group) and 570 patients with pancreatic ductal adenocarcinoma (PDAC, control group) resected at a single institution. Multivariate analyses were performed using a stage-matched Cox proportional hazard model., Results: The histology of invasive components of the IPMN cohort was tubular in 38 (62%), colloid in 16 (26%), and oncocytic in seven (12%). Compared with PDAC, invasive IPMNs were associated with a lower incidence of adverse pathological features and improved mortality by multivariate analysis (HR 0.58; 95% CI 0.39 to 0.86). In subtype analysis, this favourable outcome remained only for colloid and oncocytic carcinomas, while tubular adenocarcinoma was associated with worse overall survival, not significantly different from that of PDAC (HR 0.85; 95% CI 0.53 to 1.36). Colloid and oncocytic carcinomas arose only from intestinal- and oncocytic-type IPMNs, respectively, and were mostly of the main-duct type, whereas tubular adenocarcinomas primarily originated in the gastric background, which was often associated with branch-duct IPMN. Overall survival of patients with invasive adenocarcinomas arising from gastric-type IPMN was significantly worse than that of patients with non-gastric-type IPMN (p=0.016)., Conclusions: Tubular, colloid and oncocytic invasive IPMNs have varying prognosis, and arise from different epithelial subtypes. Colloid and oncocytic types have markedly improved biology, whereas the tubular type has a course that resembles PDAC. Analysis of these subtypes indicates that the background epithelium plays an equally, if not more, important role in defining the biology and prognosis of invasive IPMNs.

Objective: Evaluate the value of cytology relative to imaging features in risk assessment for malignancy as defined in the Sendai Guidelines., Background: The Sendai Guidelines list symptoms, cyst size >30 mm, dilated main pancreatic duct (MPD) >6 mm, mural nodule (MN) and "positive" cytology as high risk stigmata for malignancy warranting surgical triage., Methods: We reviewed clinical, radiological and cytological data of 112 patients with histologically confirmed mucinous cysts of the pancreas evaluated in a single tertiary medical center. Cytology slides were blindly re-reviewed and epithelial cells grouped as either benign or high-grade atypia (HGA) [≥high-grade dysplasia]. Histologically, neoplasms were grouped as benign (low-grade and moderate dysplasia) and malignant (in situ and invasive carcinoma). Performance characteristics of cytology relative to other risk factors were evaluated., Results: Dilated MPD, MN, and HGA were independent predictors of malignancy (p < 0.0001), but not symptoms (p = 0.29) or cyst size >30 mm (p = 0.51). HGA was the most sensitive predictor of malignancy in all cysts (72%) and in small (≤30 mm) branch-duct intraductal papillary mucinous neoplasm (BD IPMN; 67%), whereas also being specific (85 and 88%, respectively). MN and dilated MPD were highly specific (>90%), but insensitive (39%-44%). Cytology detected 30% more cancers in small cysts than dilated MPD or MN and half of the cancers without either of these high-risk imaging features., Conclusions: Cytology adds value to the radiological assessment of predicting malignancy in mucinous cysts, particularly in small BD IPMN.

Background: The delivery of radiofrequency (RF) energy to the posterior left atrium creates a risk of injury to the adjacent esophagus. Esophageal endoscopy (EGD) is used to screen patients at risk for esophageal thermal injury after RF ablation., Objective: The purpose of this study was to analyze the macroscopic features of the severity of esophageal injuries induced by RF ablation to the left atrium as seen by EGD and evaluate the association of these descriptions with the time elapsed until complete healing., Methods: This study analyzed 219 patients undergoing RF ablation for atrial fibrillation. Esophageal temperature probes were used during each ablation, and EGD was performed in cases with intraesophageal temperature ≥39°C. Repeat EGD was obtained at 10 days to evaluate for healing in all cases demonstrating esophageal injury. Serial endoscopies were repeated every 2 weeks until complete healing was documented. Lesions were classified according to severity as superficial or deep ulceration; size and shape were also noted., Results: We found 37.4% of patients (82 of 219) with esophageal intraluminal temperatures ≥39°C. Of these, 22 patients (27%) were identified with esophageal injury, with 68% being superficial ulcerations and 32% deep. On repeat EGD at 10 days, only 29% of deep ulcerations were healed, as compared with 87% of the superficial injuries (P = .0136). No difference in healing was found when analyzed for size or shape., Conclusions: The macroscopic severity of esophageal lesions detected on endoscopy the day after RF ablation can predict the time to resolution, with severe, deep ulcerations requiring a longer time to heal., (Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Objectives: Endoscopic ultrasound (EUS) may offer a diagnostic tool through the combination of imaging and guided fine-needle aspiration of pancreatic cysts. The purpose of this investigation was to determine the most accurate test for differentiating mucinous from nonmucinous cysts., Methods: The results of EUS imaging, cytology, and cyst fluid biochemical markers were prospectively collected and compared in a large single-center study (776 patients) using histology or malignant cytology as the final diagnostic standard in 198 patients., Results: The mean cyst fluid carcinoembryonic antigen (CEA) was greater in mucinous cysts (4703.0 ng/mL) compared with nonmucinous cysts (25.8 ng/mL) (P = 0.008). When using the optimal cutoff value of 109.9 ng/mL, the CEA was more accurate (86%, receiver operating characteristic area = 0.928) than EUS imaging (48%) and cytology (58%) in predicting a mucinous cyst (P < 0.0001). Malignant cysts had a mean cyst fluid CEA value (2558.2 ng/mL) similar to benign cysts (4700.2 ng/mL). Cytology (75%) more accurately diagnosed malignant cysts than EUS (66%) and CEA (62%) (P < 0.05)., Conclusions: Cyst fluid CEA concentration provides a highly accurate test for the diagnosis of a mucinous cyst, but does not distinguish benign from malignant cysts. Cytology is the most accurate test for the diagnosis of a malignant cyst.

We demonstrate for the first time that optical coherence tomography (OCT) imaging can reliably distinguish between morphologic features of low risk pancreatic cysts (i.e., pseudocysts and serous cystadenomas) and high risk pancreatic cysts (i.e., mucinous cystic neoplasms and intraductal papillary mucinous neoplasms). In our study fresh pancreatectomy specimens (66) from patients with cystic lesions undergoing surgery were acquired and examined with OCT. A training set of 20 pathology-OCT correlated tissue specimens were used to develop criteria for differentiating between low and high risk cystic lesions. A separate (validation) set of 46 specimens were used to test the OCT criteria by three clinicians, blinded to histopathology findings. Histology was finally used as a 'gold' standard for testing OCT findings. OCT was able to reveal specific morphologic features of pancreatic cysts and thus to differentiate between low-risk and high-risk cysts with over 95% sensitivity and specificity. This pilot study suggests that OCT could be used by clinicians in the future to more reliably differentiate between benign and potentially malignant pancreatic cysts. However, in vivo use of OCT requires a probe that has to fit the bore of the pancreas biopsy needle. Therefore, we have developed such probes and planned to start an in vivo pilot study within the very near future.

Objectives: Determine the effectiveness of multiple endoscopic ultrasound-guided ethanol lavage (EUS-EL) sessions for attempted ablation of pancreatic cystic lesion (PCL)., Methods: Retrospective review of patients who have undergone 2 or more EUS-EL treatments of a PCL. Eligible patients had asymptomatic, benign-appearing PCL, no previous pancreatitis, and were considered poor surgical candidates., Results: Final analysis was performed on 13 patients with suspected branch duct intraductal papillary mucinous neoplasms. The mean maximum cyst diameter at baseline and after 1 and 2 EUS-EL treatments was 20.1 ± 7.1, 17.0 ± 9.8 (P = 0.06), and 12.8 ± 9.6 mm (P = 0.0002), respectively. The mean surface area after 2 EUS-EL sessions: baseline, 5734 ± 6846 mm(2); 1 EUS-EL session, 4906 ± 9240 mm(2) (P = 0.52); and 2 EUS-EL sessions, 2311 ± 4093 mm(2) (P = 0.008). Complete resolution of the cystic lesion was not seen by computed tomography or magnetic resonance imaging in any patient after 1 EUS-EL but occurred in 5 (38%; P = 0.02) of 13 patients after 2 EUS-EL treatments. One patient had minor abdominal pain 1 day after the first EUS-EL session and 2 days after the second session., Conclusions: Compared with only 1 EUS-EL, 2 EUS-EL treatment results in a significantly greater decrease in the size and surface area of PCL and is associated with a significantly higher rate of image-defined cyst resolution.

Background: Secure esophagotomy closure methods are a critical element in the advancement of transesophageal natural orifice transluminal endoscopic surgery (NOTES) procedures., Objective: To compare the clinical outcomes in swine receiving an esophageal stent or no stent after a submucosal tunnel NOTES access procedure., Design: Prospective, randomized, controlled trial in 10 Yorkshire swine., Setting: Academic center., Intervention: An endoscopic mucosectomy device was used to create an esophageal mucosal defect. An endoscope was advanced through a submucosal tunnel into the mediastinum and thorax, and diagnostic mediastinoscopy and thoracoscopy were performed. Ten animals were randomized to no stenting (n = 5) or stenting (n = 5) with a prototype small-intestine submucosa-covered stent., Main Outcome Measurements: Gross and histologic appearance of the mucosectomy and esophagotomy sites as well as clinical outcomes., Results: There was a significant difference in the overall procedure time between the animals that received a stent (35.0 min, range 27-46.0 min) and those with no closure (19.0 min, range 17-32 min) (P value = .018). The unstented group achieved endoscopic and histologic evidence of complete re-epithelialization and healing (100%) at the mucosectomy site compared with the stented group (20%, P = .048). Stent migration into the stomach occurred in two swine. Both groups had complete closure of the submucosal tunnel and well-healed esophagotomy sites., Limitations: Animal study, small number of subjects., Conclusion: The placement of a covered esophageal stent significantly interferes with mucosectomy site healing., (Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Objective: In this study we aimed to assess the image quality and degree of vascular enhancement using low-concentration contrast media (LCCM) (300 mg I ml(-1)) and high-concentration contrast media (HCCM) (370 mg I ml(-1)) on 64-slice multidetector row CT (MDCT) abdominal CT angiography (CTA). In addition, we aimed to study the feasibility of using HCCM with a reduced total iodine dose., Methods: CTA of the abdomen on a 64-slice MDCT was performed on 15 anaesthetised pigs. Study pigs were divided into three groups of five each based on the iodine concentration and dose received: Group A (LCCM; 300 mg I ml(-1)), Group B (HCCM; 370 mg I ml(-1)) and Group C HCCM with 20% less iodine dose. The total iodine injected was kept constant (600 mg kg(-1)) in Groups A and B. Qualitative and quantitative analyses were performed to study and compare each group for image quality, visibility of the branch order of the superior mesenteric artery (SMA), artefacts, degree of enhancement in the aorta and main stem arteries and uniformity of enhancement in the aorta. Groups were compared using the analysis of variance test., Results: The image quality of 64-slice MDCT angiography was excellent with a mean score of 4.63 and confident visualisation of the third to fifth order branches of the SMA in all groups. Group B demonstrated superior vascular enhancement, as compared with Groups A and C (p≤0.05). Uniform aortic enhancement was achieved with the use of LCCM and HCCM with 20% less iodine dose., Conclusion: 64-slice MDCT angiography of the abdomen was of excellent quality. HCCM improves contrast enhancement and overall CTA image quality and allows the iodine dose to be reduced.

Objectives: The Sendai guidelines for management of patients with clinically suspected intraductal papillary mucinous neoplasms (IPMN) recommend resection of cysts > 30 mm, a dilated main pancreatic duct (MPD) > 6 mm, a mural nodule (MN), symptoms or positive cytology. Although sensitive, asymptomatic cysts, nonspecific symptoms, and a high threshold for positive cytology limit the specificity of the guidelines. We have assessed the value of cytology relative to symptom for predicting malignancy in IPMNs without high-risk imaging features., Materials and Methods: We retrospectively reviewed the clinical, radiological, and cytological data of 31 small branch-duct IPMNs without a MN. The cytological presence of high-grade atypical epithelial cells (HGA) was considered true positive, with a corresponding histology of high-grade dysplasia or invasive carcinoma. The performance of cytology versus symptoms was evaluated by calculating the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy., Results: The sensitivity (0.80), specificity (0.85), and accuracy (0.84) of HGA were higher than the corresponding performance characteristics of symptoms (0.60, 0.45, and 0.48, respectively). The NPV of no HGA on cytology was > 95%., Conclusions: Cytology is a better predictor of malignancy than symptoms, for the conservative management of small branch-duct IPMNs. Cytology contributes to a highly accurate triple negative test for malignancy in small IPMN: No dilated MPD, MN or HGA.

Background: The Sendai guidelines for risk assessment of malignancy in patients with mucinous cysts lists "positive" cytology as a high-risk feature. In the current study, the authors hypothesized that a cytological threshold of high-grade atypical epithelial cells (AEC) is a more accurate predictor of malignancy., Methods: The clinical, radiological, and cytological data of 112 patients with histologically confirmed mucinous cysts of the pancreas were reviewed. Cytology slides were blindly reviewed and cells were classified as benign, AEC, or malignant. On histology, neoplasms were grouped as benign (low-grade and moderate dysplasia) and malignant (high-grade dysplasia/carcinoma in situ and invasive carcinoma)., Results: There were 92 patients with an intraductal papillary mucinous neoplasm (IPMN) and 20 with a mucinous cystic neoplasm; 39 were malignant and 73 were benign (42 with low-grade dysplasia and 31 with moderate dysplasia). Only 28% (11 of 39) of the malignant cysts were cytologically malignant with a sensitivity of 29%, a specificity of 100%, and an accuracy of 75%. AEC detected 17 additional cancers (44% of all malignant cysts; 16% more than detected on the basis of "positive" cytology). By using AEC as a surgical triage threshold, the sensitivity was 72%, the specificity was 85%, and the accuracy was 80%, with similar values for small (≤ 3 cm) branch duct IPMN. Nine of 73 (12%) benign cysts were identified with AEC, 4 of which had moderate dysplasia. AEC had a positive predictive value of 87% for the detection of a mucinous cyst with moderate dysplasia or worse., Conclusions: AEC are a more accurate predictor of malignancy than "positive" cytology in aspirates of pancreatic mucinous cysts, including small branch duct IPMN. AEC warrant a "suspicious" interpretation for appropriate surgical triage., (Copyright © 2010 American Cancer Society.)

Background: The most common complication of uncovered biliary self-expandable metal stents (SEMSs) is tumor ingrowth. The addition of an impenetrable covering may prolong stent patency., Objective: To compare stent patency between uncovered and partially covered SEMSs in malignant biliary obstruction., Design: Multicenter randomized trial., Setting: Four teaching hospitals., Patients: Adults with inoperable distal malignant biliary obstruction., Interventions: Uncovered or partially covered SEMS insertion., Main Outcome Measures: Time to recurrent biliary obstruction, patient survival, serious adverse events, and mechanism of recurrent biliary obstruction., Results: From October 2002 to May 2008, 129 patients were randomized. Recurrent biliary obstruction was observed in 11 of 61 uncovered SEMSs (18%) and 20 of 68 partially covered SEMSs (29%). The median times to recurrent biliary obstruction were 711 days and 357 days for the uncovered and partially covered SEMS groups, respectively (P = .530). Median patient survival was 239 days for the uncovered SEMS and 227 days for the partially covered SEMS groups (P = .997). Serious adverse events occurred in 27 (44%) and 42 (62%) patients in the uncovered and partially covered SEMS groups, respectively (P = .046). None of the uncovered and 8 (12%) of the partially covered SEMSs migrated (P = .0061)., Limitations: Intended sample size was not reached. Allocation to treatment groups was unequal., Conclusions: There was no significant difference in time to recurrent biliary obstruction or patient survival between the partially covered and uncovered SEMS groups. Partially covered SEMSs were associated with more serious adverse events, particularly migration., (Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Pancreatic cystic lesions are increasingly identified on routine imaging. One specific lesion, known as intraductal papillary mucinous neoplasm (IPMN), is a mucinous, pancreatic lesion characterized by papillary cells projecting from the pancreatic ductal epithelium. The finding of mucin extruding from the ampulla is essentially pathognomonic for diagnosing these lesions. IPMNs are of particular interest due to their malignant potential. Lesions range from benign, adenomatous growths to high-grade dysplasia and invasive cancer. These mucinous lesions therefore require immediate attention to determine the probability of malignancy and whether observation or resection is the best management choice. Unresected lesions need long-term surveillance monitoring for malignant transformation. The accurate diagnosis of these lesions is particularly challenging due to the substantial similarities in morphology of pancreatic cystic lesions and limitations in current imaging technologies. Endoscopic evaluation of these lesions provides additional imaging, molecular, and histologic data to aid in the identification of IPMN and to determine treatment course. The aim of this article is to focus on the diagnostic and therapeutic endoscopic approaches to IPMN.

Background: EUS-guided ablation of pancreatic cysts is a minimally invasive technique with reported short-term, CT-defined cyst resolution rates of 33% to 79%. Follow-up results of image-defined, successful pancreatic cyst ablation are not known., Objective: To determine the durability of successful cyst resolution after EUS-guided ethanol lavage., Design: Prospective cohort study., Setting: Two tertiary-care referral hospitals in the United States., Patients: This study involved 12 patients with 1-to-5-cm, unilocular, pancreatic cysts that had previously resolved after ethanol lavage., Interventions: Follow-up CT after cyst resolution., Main Outcome Measurements: The presence or absence of residual pancreatic cysts by CT scanning after previous successful ablation., Results: In a previously reported trial, we found that CT scanning documented pancreatic cyst resolution in 12 patients (33%) after one (n = 6) or two (n = 6) ethanol lavages. These 12 cysts (median diameter 18 mm; range 10-34 mm) were located in the head/uncinate of the pancreas in 6 patients (50%) and in the body of the pancreas in 6 patients (50%). The median cyst fluid carcinoembryonic antigen (CEA) level (available in 11 patients) was 463 ng/mL (range 1.6-64,550 ng/mL; normal, 0-2.5 ng/mL). Clinical diagnoses were mucinous cystic neoplasm (MCN) in 9 patients, intraductal papillary mucinous neoplasm in 1 patient, pseudocyst in 1 patient, and serous cystadenoma (SCA) in 1 patient. Follow-up CT in 3 patients (one each of MCN, SCA, and pseudocyst) after the initial diagnosis of cyst resolution was not available. For the remaining 9 patients (75%), follow-up CT performed in a median of 26 months (range 13-39 months) after initial documentation of cyst resolution demonstrated no evidence of cyst recurrence in any patient., Limitations: Loss to follow-up of some of the cohort., Conclusions: Follow-up after successful EUS-guided ethanol ablation of pancreatic cysts, including suspected mucinous cysts, suggests a durable, image-defined resolution. Longer follow-up in these patients is needed before considering these patients "cured" of their disease., (Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: The feasibility of transanal rectosigmoid resection with transanal endoscopic microsurgery (TEM) was previously demonstrated in a swine nonsurvival model in which transgastric endoscopic assistance also was shown to extend the length of colon mobilized transanally., Methods: A 2-week survival study evaluating transanal endoscopic rectosigmoid resection with stapled colorectal anastomosis was conducted with swine using the transanal approach alone (TEM group, n = 10) or a transanal approach combined with transgastric endoscopic assistance (TEM + TG group, n = 10). Gastrotomies were created using a needleknife and balloon dilation, then closed using prototype T-tags. Outcomes were evaluated and compared between the groups using Student's t-test and Fisher's exact test., Results: Relative to the TEM group, the average length of rectosigmoid mobilized in the TEM + TG group was 15.6 versus 10.5 cm (p < 0.0005), the length of the resected specimen was 9 versus 6.2 cm (p < 0.0005), and the mean operative time was 254.5 versus 97.5 min (p < 0.0005). Intraoperatively, no organ injury or major bleeding was noted. Two T-tag misfires occurred during gastrotomy closure and four small staple line defects requiring transanal repair including one in the TEM group and three in the TEM + TG group (p = 0.2). Postoperatively, there was no mortality, and the animals gained an average of 3.4 lb. Two major complications (10%) were identified at necropsy in the TEM + TG group including an intraabdominal abscess and an abdominal wall hematoma related to T-tag misfire. Gastrotomy closure sites and colorectal anastomoses were all grossly healed, with adhesions noted in 60 and 70% and microabscesses in 50 and 20% of the gastrotomy sites and colorectal anastomoses, respectively., Conclusions: Natural orifice translumenal endoscopic surgery (NOTES) for rectosigmoid resection using TEM with or without transgastric endoscopic assistance is feasible and associated with low morbidity in a porcine survival model. Transgastric assistance significantly prolongs the operative time but extends the length of the rectosigmoid mobilized transanally, with a nonsignificant increase in complication rates related to gastrotomy creation.

Background: Gastric leak testing after natural orifice transluminal endoscopic surgery (NOTES) gastrotomy closure may help reduce the risk of leaks after transgastric procedures., Objective: To develop a novel endoscopy-based system to determine the presence of a leak after NOTES gastrotomy and to compare this system prospectively with radiographic leak testing., Design: Prospective, randomized, controlled trial., Setting: Academic Medical Center laboratory., Subjects: Fifty swine., Intervention: During the pretrial phase, an endoscopic system for the measurement of intragastric pressure was developed. In the trial phase, swine with a NOTES gastrotomy were randomized to endoscopic versus radiographic leak testing. If a leak was demonstrated, the gastrotomy was reclosed by using a second-generation prototype T-anchor system. The primary outcome was leak detection after gastrotomy closure. The secondary outcome variables included necropsy findings, peritoneal fluid analysis, histologic examination, and clinical outcome., Results: Fourteen swine were included in the pretrial phase and 36 in the randomized trial. Swine were survived for a mean of 9 days postoperatively. Endoscopic pressure monitoring demonstrated a reproducible change in intragastric pressure with insufflation; r = 0.735, P = .001 and r = 0.769, P < or = .000 for the total and maximum pressures, respectively. Post-peritoneoscopy, there was a detectable and significant decrease in the mean total and mean maximum pressures versus baseline (P = .006 and P = .009). There was no significant difference between the radiologic and endoscopic arms in leak detection rate (4/18 vs 3/18, respectively, P = .500). Clinical outcomes and mean weight gain were equivalent. There was 1 operative abdominal wall injury and no deaths., Limitations: Animal study., Conclusion: Endoscopic pressure monitoring was reproducible, demonstrated the presence of gastric leak, and was as reliable as contrast-based radiographic leak testing., (2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Pancreatic cystic lesions are being increasingly identified with the widespread use of state-of-the-art imaging. These lesions are categorized into a broad range of neoplastic cysts and inflammatory pseudocysts. Identification of a pancreatic cyst requires the clinician to focus on the main clinical challenge of the benign or malignant nature of the cyst. Neoplastic cysts range the spectrum from benign, to premalignant, to frank malignancy. The management of these lesions is difficult, and the decision to resect or observe a lesion is hampered by limitations in current imaging and tissue sampling techniques that prevent the accurate characterization of all lesions. This article reviews current guidelines for the evaluation of pancreatic cystic lesions, underscores the challenges posed by these lesions, and discusses current and future studies that will aid in patient management.

Background: Despite the wide range of natural orifice transluminal endoscopic surgery (NOTES) procedures reported to date using a transgastric endoscopic approach, complications associated with gastrotomy creation have not been described. This study was conducted to identify the incidence and types of complications related to gastrotomy creation with the needle knife puncture and balloon dilatation technique for NOTES access to the peritoneal cavity., Methods: Between May 2007 and August 2008, transgastric procedures were performed in 76 swine at a single institution. A total of 58 gastrotomies were created using the needle knife puncture and balloon dilatation technique without laparoscopic observation and 18 gastrotomies were created under laparoscopic visualization after CO(2) insufflation through a laparoscopic port. In all cases, a needle knife with an electrosurgical current of 25-W coagulation and/or 25-W cut and a wire-guided endoscopic balloon dilated to 20 mm were used to create the gastrotomy. All complications were collected prospectively and reviewed from laboratory medical records, operative reports, and necropsy findings., Results: NOTES gastrotomy-related complications occurred in 10/76 (13.2%) animals. Major complications occurred in six animals (7.9%), including four splenic lacerations, a mesenteric tear, and a fatal diaphragmatic injury. Minor complications occurred in four animals (5.3%), including three abdominal wall injuries and minor gastrotomy site bleeding. When pregastrotomy laparoscopic guidance was used, only one injury occurred in 18 animals (5.5%), but 9/58 (15.5%) gastrotomies performed without laparoscopic visualization caused some type of injury. The difference in rate of injury did not achieve statistical significance. No learning curve effect could be identified., Conclusions: Injuries to adjacent viscera occur more often than is reported with the traditional transgastric needle knife NOTES access technique. Gastric punctures should be made either with laparoscopic visualization or by other techniques such as the PEG approach or with noncutting devices to reduce the incidence of visceral injury associated with transgastric peritoneal entry.

Background: Despite advances in cross-sectional imaging and the use of molecular markers, distinguishing between benign and malignant cysts remains a clinical challenge., Aims: To identify both preoperative clinical and cyst characteristics at the time of EUS that predict malignancy., Methods: A retrospective analysis was performed on consecutive patients with pancreatic cysts who underwent endoscopic ultrasound (EUS) and surgical resection from May 1996 to December 2007 at a tertiary centre. Clinical history, EUS characteristics, cytology, tumour markers and surgical histology were collected. Predictors of malignancy were determined by univariate and multivariate analysis using logistic regression., Results: A total of 153 patients underwent a EUS and subsequent surgical intervention.Of the 153 patients, 57 (37%) had a histological diagnosis of malignancy. On univariate analysis, older age (P < 0.001), male gender (P = 0.010), jaundice (P = 0.039), history of other malignancy (P = 0.036), associated mass in cyst (P = 0.004) and malignant cytology (P < 0.001) were found to be associated with malignancy. History of pancreatitis (P = 0.008) and endoscopist impression of pseudocyst (P = 0.001) were found to be associated with benign cysts. Multivariate analysis found that only older age [Odds ratio (OR), 1.04; 95% confidence interval (CI), 1.01-1.08], male gender (OR, 2.26; 95% CI, 1.08-4.73) and malignant cytology (OR, 6.60; 95% CI, 2.02-21.58) were independent predictors of malignancy., Conclusions: Older age, male gender and malignant cytology from EUS predict malignancy at surgical resection. These characteristics may be used to estimate the probability of malignancy in a cyst and aid in management.

Background: Thoracoscopic sympathectomy is the preferred surgical treatment for patients with disabling palmar hyperhidrosis. Current methods require a transthoracic approach to permit ablation of the thoracic sympathetic chain., Objective: To develop a minimally invasive, transesophageal endoscopic technique for a sympathectomy in a swine model., Design: Nonsurvival animal study., Setting: Animal trial at a tertiary care academic center., Subjects: This study involved 8 healthy Yorkshire swine., Interventions: After insertion of a double-channel gastroscope, a Duette Band mucosectomy device was used to create a small esophageal mucosal defect. A short, 5-cm submucosal tunnel was created by using the tip of the endoscope and biopsy forceps. Within the submucosal space, a needle-knife was used to incise the muscular esophageal wall and permit entry into the mediastinum and chest. The sympathetic chain was identified at the desired thoracic level and was ablated or transected. The animals were killed at the completion of the procedure., Main Outcome Measurements: Feasibility of endoscopic transesophageal thoracic sympathectomy., Results: The sympathetic chain was successfully ablated in 7 of 8 swine, as confirmed by gross surgical pathology and histology. In 1 swine, muscle fibers were inadvertently transected. On average, the procedure took 61.4+/-24.5 minutes to gain access to the chest, whereas the sympathectomy was performed in less than 3 minutes in all cases. One animal was killed immediately after sympathectomy, before the completion of the observation period, because of hemodynamic instability., Limitations: Nonsurvival series, animal study., Conclusions: Endoscopic transesophageal thoracic sympathectomy is technically feasible, simple, and can be performed in a porcine model., (2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: EUS-guided FNA has the potential to provide diagnostic cytologic material from pancreatic lesions that are suspicious for malignancy., Objective: To determine the operating characteristics of EUS-FNA in the diagnosis of pancreatic adenocarcinoma and pancreatic neuroendocrine neoplasms (PENs)., Design: Retrospective analysis of a prospectively maintained database., Setting: Academic tertiary-care center., Patients: This study involved 559 patients undergoing evaluation of pancreatic masses or diffuse pancreatic parenchymal abnormalities., Main Outcome Measurements: Performance characteristics of EUS-FNA of pancreatic adenocarcinoma and PEN., Results: From January 1997 to December 2005, 737 patients undergoing initial EUS-FNA evaluation for a pancreatic mass were identified. In the final analysis, 559 patients with 560 FNA-sampled lesions were included. Overall, 442 lesions were pancreatic adenocarcinoma, and 40 were PEN. The sensitivity of EUS-FNA in the diagnosis of pancreatic adenocarcinomas and PENs was 77% (95% CI, 72.8%-80.8%) and 68% (95% CI, 50.8%-80.9%), respectively, using strict cytologic criteria. Reclassification of atypical and suspicious cytologies as diagnostic of malignancy resulted in a sensitivity of 93%, (95% CI, 90.9%-99.7%) in adenocarcinoma and 80% (95% CI, 63.9%-90.4%) in PEN. Tumor size, tumor location, and number of needle passes did not significantly influence diagnosis, but immediate cytologic evaluation was influential., Limitations: Retrospective analysis at a single center., Conclusions: In a large, well-controlled study, EUS-FNA was found to be an accurate test (80%) for the detection of pancreatic adenocarcinoma by using aspiration cytology. The accuracy of the examination is significantly improved (94%) when atypical and suspicious samples are considered positive. Finally, only 2 to 3 FNA passes may be needed to achieve a good diagnostic yield., (2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: The success of natural orifice surgery depends on a reliable, secure closure of the opening in the gut. Few tests of the integrity of these closures have been published., Objective: To determine whether a gastrotomy can be closed safely and effectively from within the stomach by using looped T-anchors-a novel, endoscopically placed device., Design: Head-to-head comparison trial of 2 closure methods in 9 explanted porcine stomachs., Setting: Animal laboratory., Intervention: Paired gastrotomies were made in porcine explants. One was closed by using endoscopic clips, and the other was closed by using modified T-anchors in a purse-string fashion., Main Outcome Measurements: Gastric transmural pressure gradients at bursting of these closures were measured while the explanted stomachs were inflated with a high-pressure insufflator., Results: The mean burst pressure of the looped T-anchors was 27.3 mm Hg, whereas that of the clip closures was 14 mm Hg. By using 10 mm Hg as a threshold for a "secure" closure, 7 of 9 clip closures failed to meet the threshold value, whereas all 9 of the T-anchor closures met or exceeded the threshold value (P = .0023, 2-tailed Fisher exact test)., Limitation: Nonsurvival study., Conclusion: Looped T-anchors provide a secure gastric closure for natural orifice surgery and are superior to endoscopic clips for this purpose.

The objective of this study was to evaluate the efficacy of EUS-guided CPN for pain relief in patients with chronic pancreatitis and pancreatic cancer. An initial search identified 1,439 reference articles, of which 130 relevant articles were selected and reviewed. Data was extracted from 8 studies (N = 283) for EUS-guided CPN for pain due to pancreatic cancer and nine studies for chronic pancreatitis (N = 376) which met the inclusion criteria. With EUS-guided CPN, the pooled proportion of patients with pancreatic cancer that showed pain relief was 80.12% (95% CI = 74.47-85.22). In patients with pain due to chronic pancreatitis, EUS-guided CPN provided pain relief in 59.45% (95% CI = 54.51-64.30). In conclusion, EUS-guided CPN offers a safe alternative technique for pain relief in patients with chronic pancreatitis or pancreatic cancer. In patients with pain due to chronic pancreatitis, better techniques or injected materials are needed to improve the response.

Objectives: To evaluate the role of computed tomography (CT) perfusion in detection of pancreatic necrosis and pancreatitis after endoscopic ultrasound-guided ethanol ablation of porcine pancreas and to correlate the evaluation with histopathology., Methods: Under endoscopic ultrasound guidance, 0.9% saline (control) and ethanol at 60%, 80%, and 100% concentrations were injected into the pancreatic tails of 4 pigs. On day 4, dynamic perfusion CT of the pancreas was performed. Perfusion analysis and evaluation of enhancement characteristics were done and correlated with histopathology., Results: Ethanol injections at 80% and 100% concentrations resulted in focal necrosis surrounded by focal pancreatitis, whereas 60% ethanol injection caused severe focal pancreatitis with microscopic necrosis. The necrotic area revealed reduced blood flow, blood volume, permeability-surface area product, and increased mean transit time compared with pancreatitis and normal tissue (P < or = 0.001). In the control pig, no pancreatitis or necrosis was observed on perfusion images and histopathology., Conclusions: Pancreatic necrosis and pancreatitis after ethanol injection reduced the tissue perfusion on CT in comparison to normal tissue, with the changes being more substantial in necrosis than pancreatitis. These findings have possible implications in the accurate detection of pancreatic necrosis in patients with severe pancreatitis.

Background: Surgery for pancreatic cysts is associated with significant morbidity. A pilot study previously demonstrated the safety of EUS-guided ethanol lavage of pancreatic cysts., Objective: To determine whether EUS-guided ethanol lavage would decrease pancreatic cyst size more than saline solution lavage., Design: Prospective, multicenter, randomized trial., Setting: Two tertiary referral hospitals in the United States., Patients: Patients referred for EUS with a 1- to 5-cm unilocular pancreatic cyst were randomized to blinded ethanol or saline solution lavage. Three months later, the cyst diameter was remeasured by EUS, and a second unblinded ethanol lavage was performed., Interventions: EUS-guided pancreatic cyst lavage., Main Outcome Measurements: Cyst ablation based on size changes from follow-up EUS, CT, and histology of resected specimens., Results: Of 58 patients randomized, 16 were excluded and 42 underwent initial ethanol (n = 25) or saline solution (n = 17) lavage. Ethanol lavage resulted in a greater mean percentage of decrease in cyst surface area (-42.9; 95% CI, -58.4 to -27.4) compared with saline solution alone (-11.4; 95% CI, -25.0 to 2.2; P = .009). Nineteen (76.0%) of 25 and 14 (82.3%) of 17 patients randomized to ethanol and saline solution, respectively, underwent a second ethanol lavage. A follow-up CT scan demonstrated resolution in 12 (33.3%) of 36 cysts. Histology of 4 resected cysts demonstrated epithelial ablation ranging from 0% (saline solution alone) to 50% to 100% (1 or 2 ethanol lavages). Complication rates were similar in all groups., Limitation: Short-term follow-up., Conclusions: EUS-guided ethanol lavage results in a greater decrease in pancreatic cyst size compared with saline solution lavage with a similar safety profile. Overall CT-defined complete pancreatic cyst ablation was 33.3%.

Background: Natural orifice transluminal endoscopic surgery (NOTES) research has primarily involved case series reports of low-risk procedures. Distal pancreatectomy has significant postoperative morbidity and would permit rigorous examination in a controlled trial setting., Objective: To compare endoscopic transgastric distal pancreatectomy (ETDP) and laparoscopic distal pancreatectomy (LDP)., Design: Prospective, randomized, controlled trial., Setting: Academic hospital., Subjects: Forty-one swine, 28 block randomized., Interventions: LDP was performed with 3 trocars and stapled transection of the pancreas. ETDP was performed via a gastrotomy, with 1 trocar for visualization, by using endoloop placement, snare transection, and purse-string gastrotomy closure., Main Outcome Measurements: Clinical examination, CT, serum chemistries, necropsy, peritoneal fluid analysis, and histologic examination., Results: Swine were survived for 8 days. The procedure time for ETDP was significantly greater than for LDP (1:52 vs 0:33 [hours:minutes]; P = .00). Pancreatic specimen weight was similar (4.1 g vs 5.5 g; P = .108). Postoperatively, 26 of 28 animals thrived. In the LDP group, 1 death caused by pancreatic leak and renal failure occurred on day 1. In the ETDP group, 1 death caused by pneumothorax occurred intraoperatively. The necropsy, CT, and histologic examinations revealed focal resection-margin necrosis in 3 to 7 swine in the ETDP group with no proximal necrosis or pancreatitis. The groups were equivalent clinically, by survival, and by serum and peritoneal fluid analysis. The gastrotomy closure was associated with small serosal adhesions, but no gross abscess or necrosis., Limitation: Animal study., Conclusions: In the largest controlled trial of NOTES orifice surgery to date, there was no clinical or survival difference between NOTES and laparoscopic approaches.

Background: Cryoenergy is being increasingly used for atrial fibrillation (AF) ablation, but the thermal effect of cryoenergy on the esophagus remains undefined., Objective: This study examines the esophageal effects of cryoenergy used during AF ablation., Methods: Catheter ablation was performed using a cryoballoon catheter in 67 AF patients (Cryoballoon group), and a spot cryocatheter to complete irrigated radiofrequency lesion sets at segments in close proximity to the esophagus in 7 AF patients (Cryo-Focal group). A temperature probe monitored the luminal esophageal temperature (LET) in all patients; LET changes did not guide therapy. Post-procedural endoscopy was performed on 35 of 67 (52%) Cryoballoon and all Cryo-Focal patients., Results: Significant LET decreases (>1 degrees C) occurred in 62 of 67 (93%) Cryoballoon patients. LET continued to decrease after termination of cryoablation before recovering to normal. Temperature decreases were more pronounced during ablation at the inferior (3.1 degrees C) than superior pulmonary veins (1.5 degrees C); the lowest observed temperature was 0 degrees C. Post-procedural endoscopy showed esophageal ulcerations in 6 of 35 (17%) patients. There were no atrial-esophageal fistulas, and all ulcers had healed on follow-up endoscopy. Patients with and without ulceration differed with respect to mean LET nadir, cumulative LET decrease, and number of LETs <30 degrees C. In the Cryo-Focal group, 6 +/- 2 spot cryolesions per patient resulted in 1.3 +/- 1 LET decreases per patient, and an absolute nadir of 32.5 degrees C., Conclusion: Cryoballoon ablation can cause significant LET decreases, resulting in reversible esophageal ulcerations in 17% of patients. No ulcerations occurred with adjunctive spot cryoablation at regions near the esophagus during radiofrequency ablation procedures.

Background: The management of patients with pancreatic cysts is based on the preoperative distinction of nonmucinous and mucinous cysts in general and of benign and malignant cysts in particular. An accurate diagnosis is challenging, because endoscopic ultrasound (EUS) and cyst fluid analysis for carcinoembryonic antigen (CEA) and cytology have low sensitivity and specificity. Currently, molecular analysis is a commercially available test that promises an accurate diagnosis. The objective of the current study was to correlate a commercially provided molecular diagnosis (MDx) with a clinical consensus diagnosis (CCD) in the general categories of malignant, benign mucinous, and benign nonmucinous pancreatic cysts., Methods: Pancreatic cysts that had aspirated fluid submitted for a commercially available molecular test (PathFinderTG) were reviewed. The CCD, defined by histology, malignant cytology, or 2 concordant tests (such as EUS, cytology, or CEA >/=192 ng/mL for mucinous cysts), was categorized as malignant, benign mucinous, or benign nonmucinous cyst in 35 patients. Their MDx, based on the PathFinderTG report, including analysis of k-ras mutation, loss of heterozygosity, and quantity/quality of DNA, also was classified as malignant, benign mucinous, or benign nonmucinous cyst. These 2 diagnoses were compared and correlated., Results: The concordance between CCD and MDx was 5 of 6 (83%), 13 of 15 (87%), and 13 of 14 (93%), respectively, for malignant, benign mucinous, and benign nonmucinous cysts, with an overall Cohen kappa statistic of 0.816. The sensitivity, specificity, and positive predictive value of the MDx were 83%, 100%, and 100%, respectively, for a malignant cyst and 86%, 93%, and 95%, respectively for a benign mucinous cyst., Conclusions: Molecular analysis of pancreatic cyst fluid adds diagnostic value to the preoperative diagnosis with high sensitivity, specificity, and positive predictive value for the diagnosis of malignant and benign mucinous pancreatic cysts., (2009 American Cancer Society.)

Gastrointestinal stromal cell tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract and are frequently detected on routine endoscopy. Although only approximately 10-30% of GISTs are clinically malignant, all may have some degree of malignant potential. Preoperative determination of malignancy risk can be estimated from tumor size and location, but reliable histopathologic criteria are not currently available. Given such biological uncertainty, accurate diagnosis is essential to differentiate these lesions from other truly benign, subepithelial tumors. Endoscopic ultrasound-guided fine-needle aspiration has emerged as an important procedure to secure a tissue diagnosis of a GIST. When encountering GISTs, gastroenterologists are faced with challenging management decisions, especially in the face of small, incidentally discovered lesions. The majority of localized GISTs are managed via surgical resection, although a select few may be observed using serial endoscopic ultrasound examinations. This Review provides a general overview of GISTs, with an emphasis on their endoscopic diagnosis, the management of localized disease, and the management of incidentally discovered GISTs.

Background: The role of pancreatic cyst fluid DNA analysis in evaluating pancreatic cysts remains unclear., Objective: Our purpose was to evaluate the utility of a detailed DNA analysis of pancreatic cyst fluid to diagnose mucinous and malignant cysts., Design: Prospective, multicenter study., Patients: Patients with pancreatic cysts presenting for EUS evaluation., Intervention: EUS-guided pancreatic cyst aspirates cytology evaluation, carcinoembryonic antigen (CEA) level determination, and a detailed DNA analysis; incorporating DNA quantification, k-ras mutation and multiple allelic loss analysis, mutational amplitude, and sequence determination., Main Outcome Measurements: Cyst fluid analysis compared with surgical pathologic or malignant cytologic examination., Results: The study cohort consisted of 113 patients with 40 malignant, 48 premalignant, and 25 benign cysts. Cyst fluid k-ras mutation was helpful in the diagnosis of mucinous cysts (odds ratio 20.9, specificity 96%), whereas receiver-operator characteristic curve analysis indicated optimal cutoff points for allelic loss amplitude (area under the curve [AUC] 0.79; optimal value > 65%) and CEA (AUC 0.74; optimal value >148 ng/mL). Components of DNA analysis detecting malignant cysts included allelic loss amplitude over 82% (AUC 0.9) and high DNA amount (optical density ratio >10, AUC 0.79). The criteria of a high amplitude k-ras mutation followed by allelic loss showed maximum specificity (96%) for malignancy. All malignant cysts with negative cytologic evaluation (10/40) could be diagnosed as malignant by using DNA analysis., Limitations: Limited follow-up, selection bias., Conclusions: Elevated amounts of pancreatic cyst fluid DNA, high-amplitude mutations, and specific mutation acquisition sequences are indicators of malignancy. The presence of a k-ras mutation is also indicative of a mucinous cyst. DNA analysis should be considered when cyst cytologic examination is negative for malignancy.

Background: Nodal staging in patients with rectal cancer predicts prognosis and directs therapy. Published data on the accuracy of endoscopic ultrasound (EUS) for diagnosing nodal invasion in patients with rectal cancer has been inconsistent., Aim: To evaluate the accuracy of EUS in diagnosing nodal metastasis of rectal cancers., Method: Study Selection Criteria: Only EUS studies confirmed by surgical histology were selected. Data Collection and Extraction: Articles were searched in Medline, Pubmed, and CENTRAL., Statistical Method: Pooling was conducted by both fixed-effects model and random-effects model., Results: The initial search identified 3610 reference articles in which 352 relevant articles were selected and reviewed. Data were extracted from 35 studies (N = 2732) that met the inclusion criteria. Pooled sensitivity of EUS in diagnosing nodal involvement by rectal cancers was 73.2% (95% confidence interval [95% CI] 70.6-75.6). EUS had a pooled specificity of 75.8% (95% CI 73.5-78.0). The positive likelihood ratio of EUS was 2.84 (95% CI 2.16-3.72), and negative likelihood ratio was 0.42 (95% CI 0.33-0.52). All the pooled estimates, calculated by fixed- and random-effect models, were similar. SROC curves showed an area under the curve of 0.79. The P for chi-squared heterogeneity for all the pooled accuracy estimates was >.10., Conclusions: EUS is an important and accurate diagnostic tool for evaluating nodal metastasis of rectal cancers. This meta-analysis shows that the sensitivity and specificity of EUS is moderate. Further refinement in EUS technologies and diagnostic criteria are needed to improve the diagnostic accuracy.

In this paper we review the state-of-the-art in endoscopic interventions for obesity treatment and make best practice recommendations for weight loss surgery (WLS). We performed a systematic search of English-language literature published between April 2004 and June 2008 in MEDLINE and the Cochrane Library on WLS and endoscopic interventions, endoscopically placed devices, minimally invasive surgery, image-guided surgery, endoluminal surgery, endoscopic instrumentation, interventional gastroenterology, transluminal surgery, and natural orifice transluminal surgery. We also searched the literature on endoscopic interventions and WLS and patient safety. We identified 36 pertinent articles, all of which were reviewed in detail; assessed the current science in endoscopic interventions for WLS; and made best practice recommendations based on the latest available evidence. Our findings indicate that endoscopic interventions and endoscopically placed devices may provide valuable approaches to the management of WLS complications and the primary management of obesity. Given the rapid changes in endoscopic technologies and techniques, systematic literature review is required to address issues related to the emerging role of endoluminal surgery in the treatment of obesity. These interventions should be a high priority for development and investigation.

Objective: To define how patients with pancreatic cysts are being diagnosed and treated., Design: Retrospective case series., Setting: University-affiliated tertiary care center., Patients: Four hundred one patients evaluated in the Department of Surgery between January 2004 and December 2007., Main Outcome Measures: Clinical management, histological diagnosis, and results of surveillance., Results: Pancreatic cysts were incidentally discovered in 71% (284 of 401) of patients. There was no statistically significant difference in age (60.4 vs 63.1 years; P = .10), cyst size (31 vs 27 mm; P = .12), or histological diagnosis between symptomatic patients and patients with incidentally discovered cysts. Whereas the majority of symptomatic patients had their cystic neoplasms resected on diagnosis, 50% (142 of 284) of incidentally discovered cysts were initially managed nonoperatively. Of the patients who were managed with surveillance, 13 (8%) subsequently underwent resection after a median of 2.1 years because of an increase in cyst size, development of symptoms, increasing tumor markers, worrisome endoscopic ultrasonography findings, or patient anxiety. The most common diagnosis among resected lesions was either main-duct intraductal papillary mucinous neoplasm (25%) or branch-duct intraductal papillary mucinous neoplasm (23%). Invasive cancer was found in 29 of 256 (11%) resected cystic neoplasms, 9 of which were incidentally discovered, and in 7% (1 of 13) of patients who underwent watchful waiting prior to resection., Conclusions: Incidentally discovered pancreatic cystic neoplasms composed 71% of our series, of which 50% were immediately resected. Subsequent morphologic changes or development of symptoms prompted an operation in 8% of patients after a period of surveillance. Invasive malignancy was present in 11% of all resected specimens but in 38% of main-duct intraductal papillary mucinous neoplasms.

Endoscopic mucosal resection (EMR) is being advocated as a diagnostic, staging, and therapeutic technique for the management of Barrett esophagus (BE)-related neoplasia. With the emergence of new endoluminal therapy including EMR for the treatment of BE-related superficial adenocarcinomas, accurate staging has become crucial to select patients for different treatment arms. Intramucosal adenocarcinomas can be successfully treated by endoluminal techniques, whereas submucosal invasive tumors with a greater risk of lymph node metastasis are likely candidates for esophagectomy. Endoscopic ultrasound (EUS) is used to stage superficial BE-related neoplasms, yet endoscopic staging can be incongruent to that obtained after pathologic examination. In this study, we sought to determine morphologic factors, which may influence EUS staging in 35 cases with intramucosal adenocarcinoma diagnosed by subsequent EMR, focusing on tumor characteristics and structural changes associated with BE. Among the latter duplication of the muscularis mucosae, either fragmented or well-organized, was seen in 64% of 11 cases that were overstaged as having submucosal invasion by EUS, compared with 38% of those accurately staged. A greater vertical thickness of the tumor was also associated with overstaging by EUS (1.61+/-0.75 mm in the discordant vs. 1.16+/-0.67 mm in the concordant groups, P=0.028). The results illustrate how morphologic factors may affect EUS staging of superficial esophageal adenocarcinomas. EUS alone is not sufficient for staging these neoplasms precisely, and to accurately stratify patients into different treatment arms, EMR should play a role as a complementary staging modality.

This review introduces some of the novel endoscopic modalities used for the treatment of superficial neoplasms arising in the setting of Barrett's esophagus, namely endoscopic mucosal resection and photodynamic therapy. We describe the appropriate technical details for pathologists to know to effectively communicate with the gastroenterologists as well as the pitfalls in the evaluation of endoscopic mucosal resection specimens and post photodynamic therapy follow-up biopsies.

Intraductal papillary mucinous neoplasms have gained recognition in recent years as premalignant precursors to pancreatic cancer that enable early detection and often are found incidentally at imaging. Accurate diagnosis and optimal, finely tuned management of these lesions are important and require collaboration across various disciplines, including radiology, endoscopy, surgery, and pathology. Several imaging modalities can visualize these lesions adequately, each with specific advantages and disadvantages. Multidetector computed tomography and magnetic resonance cholangiopancreatography are generally the first-line imaging modalities; endoscopic imaging such as endoscopic ultrasound and endoscopic retrograde cholangiopancreatography are beneficial when the former 2 modalities are equivocal. Surgical candidates generally include patients with main duct lesions or branch duct lesions greater than 3 cm or any possessing a solid component. A management algorithm indicating when surgery should be pursued is proposed. For nonsurgical and postsurgical patients, follow-up management is important to monitor growth and recurrence, and risks from repeated radiation exposure should be taken into account. Furthermore, issues of multifocality and increased predisposition of the pancreas to ductal adenocarcinoma must be addressed at follow-up evaluation. A follow-up management algorithm also is proposed in this review.

Published data on accuracy of endoscopic ultrasound (EUS) in differentiating T stages of rectal cancers is varied. Study selection criteria were to select only EUS studies confirmed with results of surgical pathology. Articles were searched in Medline and Pubmed. Pooling was conducted by both fixed and random effects models. Initial search identified 3,630 reference articles, of which 42 studies (N = 5,039) met the inclusion criteria and were included in this analysis. The pooled sensitivity and specificity of EUS to determine T1 stage was 87.8% [95% confidence interval (CI) 85.3-90.0%] and 98.3% (95% CI 97.8-98.7%), respectively. For T2 stage, EUS had a pooled sensitivity and specificity of 80.5% (95% CI 77.9-82.9%) and 95.6% (95% CI 94.9-96.3%), respectively. To stage T3 stage, EUS had a pooled sensitivity and specificity of 96.4% (95% CI 95.4-97.2%) and 90.6% (95% CI 89.5-91.7%), respectively. In determining the T4 stage, EUS had a pooled sensitivity of 95.4% (95% CI 92.4-97.5%) and specificity of 98.3% (95% CI 97.8-98.7%). The p value for chi-squared heterogeneity for all the pooled accuracy estimates was > 0.10. We conclude that, as a result of the demonstrated sensitivity and specificity, EUS should be the investigation of choice to T stage rectal cancers. The sensitivity of EUS is higher for advanced disease than for early disease. EUS should be strongly considered for T staging of rectal cancers.