Manu Nayar

Diagnostic accuracy of quantitative EUS elastography for discriminating malignant from benign solid pancreatic masses: a prospective, single-center study

BACKGROUND Recent data suggest that quantitative EUS elastography, a novel technique that allows real-time quantification of tissue stiffness, can accurately differentiate malignant from benign solid pancreatic masses. OBJECTIVE To externally validate the diagnostic utility of this technique in an independent cohort. DESIGN AND SETTING Prospective, single-center study. PATIENTS, INTERVENTIONS, AND METHODS: A total of 104 patients with evidence of a solid pancreatic mass on cross-sectional imaging and/or endosonography underwent 111 quantitative EUS elastography procedures. Multiple elastographic measurements of the mass lesion and soft-tissue reference areas were undertaken, and the corresponding strain ratios (SRs) were calculated. The final diagnosis was based on pancreatic cytology or histology. MAIN OUTCOME MEASUREMENTS The area under the receiver-operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of quantitative EUS elastography for discriminating malignant from benign pancreatic masses. RESULTS The final diagnoses were primary pancreatic carcinoma (71.2%), neuroendocrine tumor (10.6%), metastatic cancer (1.9%), and pancreatitis (16.3%). Malignant masses had a higher SR (P = .01) and lower mass elasticity (P = .003) than inflammatory ones. The areas under the receiver-operating characteristic curve for the detection of pancreatic malignancy of both SR and mass elasticity (0.69 and 0.72, respectively) were less favorable than reported recently. At the cut points providing the highest accuracy in this cohort (4.65 for SR and 0.27% for mass elasticity), quantitative EUS elastography had a sensitivity of 100.0% and 95.7%, specificity of 16.7% and 22.2%, positive predictive value of 86.1% and 86.4%, negative predictive value of 100.0% and 50.0%, and overall accuracy of 86.5% and 83.8%, respectively. LIMITATIONS Relatively small number of patients with benign disease. CONCLUSION In the largest single-center study to date, the diagnostic utility of quantitative EUS elastography for discriminating pancreatic masses was modest, suggesting that it may only supplement rather than supplant the role of pancreatic tissue sampling in the future.

EUS-FNA versus Biliary Brushings and Assessment of Simultaneous Performance in Jaundiced Patients with Suspected Malignant Obstruction

CONTEXT Individuals with suspected malignant biliary obstruction commonly undergo ERCP for drainage and tissue sampling via biliary brushings. EUS with EUS-FNA facilitates staging and potentially more accurate tissue sampling. OBJECTIVE The aim is to compare the diagnostic performance of EUS-FNA and ERCP with biliary brushings (ERCP-BB) in the diagnosis of pancreatobiliary carcinoma and the utility of combining the two procedures under conscious sedation. DESIGN Retrospective analysis of a prospectively maintained database. PATIENTS Thirty-seven patients with suspected malignant obstructive jaundice underwent 39 paired procedures, either combined (n=22) or within a few days (n=17). RESULTS Using strict cytological criteria the sensitivity of EUS-FNA in the diagnosis of malignancy was 52.9% (95% CI: 35.1-70.2%) versus 29.4% (95% CI: 15.1-47.5%) for ERCP-BB. Combining the two tests improved sensitivity to 64.7% (95% CI: 46.5-80.3%) which was significantly better than ERCP-BB alone (P=0.001) but not EUS-FNA alone (P=0.125). When both procedures were performed under the same conscious sedation, there was a significant difference (P=0.031) between the sensitivity of EUS-FNA (52.6%; 95% CI: 28.9-75.6%) and that of ERCP-BB (21.1%; 95% CI: 6.1-45.6%). When both procedures were performed together the mean±SD in-room time was 79±14 min (range: 45-105 min). Two of the patients (9.1%) had a complication. CONCLUSIONS In patients undergoing EUS-FNA and ERCP-BB under the same sedation, EUS-FNA was significantly more sensitive in diagnosing malignancy. Combining the results of both tests improved diagnostic accuracy. Combining therapeutic ERCP and EUS-FNA under the same conscious sedation is feasible, with a complication rate similar to that of ERCP alone.

Endoscopic drainage of walled-off pancreatic necrosis using a novel self-expanding metal stent.

BACKGROUND AND STUDY AIMS This report describes the use of a novel, fully covered, self-expanding metal stent (FCSEMS) for endoscopic ultrasound (EUS)-guided drainage of walled-off pancreatic necrosis (WON). PATIENTS AND METHODS Patients with WON, as defined by the revised Atlanta Criteria, were included in this open-lable, two-center, observational study. The WON was punctured using a cystotome, and the FCSEMS was inserted under fluoroscopic guidance. Necrosectomy procedures were performed as necessary. RESULTS A total of 19 patients were included. The median maximum collection size was 15 cm with a median of 50 % necrosis. A total of 14/19 patients underwent necrosectomy, requiring a median of 4 procedures. Resolution or reduction in the size of collection by at least 80 % was achieved in all patients. Percutaneous or surgical drainage was required in three patients. Five stents migrated or dislodged. One patient had abdominal pain post-procedure. Five patients died during follow-up (three from multi-organ failure, and two unrelated to pancreatitis). CONCLUSIONS Use of this stent is feasible and safe for drainage of WON. However, stent displacement rates were high, and improvements to the stent design are required before it can be advocated for routine use in WON.

Diagnostic Performance of Endoscopic Ultrasound (EUS)/ Endoscopic Ultrasound - Fine Needle Aspiration (EUS-FNA) Cytology in Solid and Cystic Pancreatic Neuroendocrine Tumours

BACKGROUND AND AIMS Our study aimed to assess the sensitivity of EUS and EUS-FNA for pancreatic neuro-endocrine tumors (pNETs) and compare performance over two consecutive 4 year 2 month periods, to investigate the comparative performance between solid and cystic pNETs and determine the incremental yield of EUS +/- FNA in individuals with a mass not diagnosed as a pNET after cross-sectional imaging. METHODS A retrospective review of a prospectively maintained database was carried out to identify all pNET patients who underwent EUS-FNA between April 2003 and September 2011. RESULTS A final diagnosis of solid and cystic pNETs was made in 43 and 10 patients, respectively. Overall, the yield of combined EUS imaging and cytology was significantly higher than that of CT and/or MRI (p< 0.05) across all groups [solid (83.7% vs. 41.8%), cystic (70% vs. 10%) and combined solid-cystic (81.1% vs. 35.8%)]. The yield of combined EUS imaging and cytology was significantly better than EUS imaging alone (p<0.05) in the solid (83.7% vs. 58%) and combined pNET cohort (81.1% vs. 52.8%) of patients. After a non-diagnostic CT and or MRI, EUS/EUS-FNA confirmed pNET in 19 out of 25 patients (76.0%) with solid pNETs and 6 out of 9 patients (66.7%) with cystic pNETs. CONCLUSION EUS and EUS-FNA had a significant clinical impact in the 25/34 of cases where pNET was not suspected after initial cross-sectional imaging.

Effect of dedicated and supervised training on achieving competence in EUS-FNA of solid pancreatic lesions

Abstract Background and Aim. The diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been suggested as a benchmark of quality performance in EUS. However, there is paucity of data on the training requirement for competency in EUS-FNA of the pancreas. KO commenced the service without prior formal training in EUS-FNA. A formally trained colleague (MN) who underwent a fellowship in the same unit was appointed to a substantive post in 2007. The aims of the study were to assess if a dedicated training program in pancreaticobiliary (PB) EUS-FNA of solid lesions: (1) produced better results at the outset of independent practice than produced at the initiation of service without formal training and (2) produced results comparable with those of an experienced endosonographer. Material and methods. This is a retrospective review comparing the first 80 consecutive cases at the onset of practice of operator KO1 (2003/2004) and MN (2007/2008) as well as consecutive cases of operator KO2 (2007/2008) in the same time frame as the initial cases of operator MN. Results. There was a significant difference in EUS-FNA sensitivity for pancreatic malignancy between operator KO1 (56%) and operator MN (77%) p < 0.05. There was no significant difference in test performance between operator KO2 (82%) and MN (77%) (p > 0.05). Conclusion. Our data show that formal training in PB EUS produces test performance at the outset of independent practice that is comparable with an experienced endosonographer, in line with the published standards for EUS-FNA of the pancreas and significantly better than that achieved without training.

Does On-Site Adequacy Assessment by Cytotechnologists Improve Results of EUS guided FNA of Solid Pancreaticobiliary Lesions?

CONTEXT Rapid onsite adequacy assessment is stated to improve the diagnostic performance of EUS-FNA. OBJECTIVES The aim of this study was to establish if the introduction of adequacy assessment performed by a biomedical scientist (cytotechnologist) to an established EUS service improved the diagnostic accuracy of EUS guided FNA of solid pancreaticobiliary lesions. DESIGN AND PATIENTS This retrospective study includes all patients with solid pancreaticobiliary lesions who underwent EUS-FNA from April 2009 to September 2010. An in room cytotechnologist was present for 2 out of the 4 weekly EUS lists and therefore there were two groups identified: Group 1, cytotechnologist absent; and Group 2, cytotechnologist present. RESULTS There were 82 patients in Group 1 and 97 patients in Group 2. There was no statistically significant difference in the number of passes (4.1 vs. 4.3), the inadequate aspirate rate (7.3% vs. 5.1%) or the mean size of the lesions (34.7 vs. 32.6 mm) between the groups. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value in Group 1 were 89%, 88%, 100%, 100% and 50% respectively. The results in Group 2 were 91%, 90%, 100%, 100% and 69% respectively. There was no statistically significant difference between the two groups. CONCLUSIONS In this study the adequacy assessment performed by a cytotechnologist did not improve the diagnostic accuracy of EUS-FNA. In an established EUS-FNA service with low inadequate aspirate rates, onsite adequacy assessment may not improve results of the test.

Endoscopic ultrasound in patients with normal liver blood tests and unexplained dilatation of common bile duct and or pancreatic duct

Abstract Objective. To determine the yield of endoscopic ultrasound (EUS) in the investigation of patients with normal liver function tests (LFTs) and unexplained dilatation of common bile duct (CBD) and/or pancreatic duct (PD), following CT and/or magnetic resonance cholangiopancreatography. Materials and methods. Consecutive patients undergoing linear EUS between January 2007 and August 2011 for the indication of dilated CBD and/or PD, normal LFT, and nondiagnostic cross-sectional imaging formed the study group. The study was performed as a retrospective analysis of prospectively collected data. Results. During the study period, 83 patients (CBD and PD dilatation n = 38, PD dilatation n = 5, CBD dilatation n = 40) met the inclusion criteria and underwent EUS. Five (13.1%) of the CBD and PD groups had a new finding, which in one (2.6%) case was causal. In this group, men were significantly more likely to have a new finding (p = 0.012). Eight (20%) of the CBD group had a new finding, which in seven (17.5%) cases was causal. In the CBD group, cholecystectomy was significantly (p = 0.005) more common in those without a finding. Three (60%) of the PD group had a finding on EUS, all of which were causal, including a case of pancreatic malignancy. Conclusion. There is a significant yield from EUS in individuals with isolated PD dilatation and isolated CBD dilatation. Previous cholecystectomy is significantly associated with a negative EUS in the group with isolated CBD dilatation. The yield in those with CBD and PD dilatation was low and a finding was more likely in males.

Multicenter experience from the UK and Ireland of use of lumen-apposing metal stent for transluminal drainage of pancreatic fluid collections

Background and study aims  Pancreatic fluid collection (PFC) is a common complication of pancreatitis for which endoscopic ultrasound-guided drainage is first-line treatment. A new single-device, lumen-apposing, covered self-expanding metal stent (LAMS) has been licensed for PFC drainage. We therefore present our multicenter experience with the LAMS for PFC drainage in a multicenter prospective case series to assess success and complication rates. Patients and methods  All adult patients from 11 tertiary centers who had LAMS placement for PFC from July 2015 to July 2016 were included. Data including indications, technical success, clinical success, collection resolution, stent removal, early and late adverse events (AEs), mortality and recurrence at 6 months were collected. Results  116 patients, median age 52.5 years (range 16 – 80) and 67 % male, were treated with a single LAMS in each case. The indication was walled off necrosis (WON) in 70 and pseudocyst in 46. Median size of the PFC was 11 cm (5 – 21 cm) and the estimated median necrotic volume in WON was 30 % (5 % – 90 %). Stent insertion was technically successful in 115 (99.1 %) and clinically successful in 109 (94 %). Early serious AEs (SAEs): n = 7 sepsis, n = 1 stent blockage with food, n = 1 stent migration requiring laparotomy, n = 1 stent dislodgement and n = 1 bleeding requiring emboliZation. Late AEs: n = 1 buried stent and n = 1 esophageal fistula. Non-procedure-related deaths: n = 3 (2.5 %). Conclusion  This multicenter case series demonstrates that use of the new LAMS is feasible, effective and relatively safe in draining PFC with a technical success rate of 99 % and cumulative SAE rate of 11.2 %.

Lumen-apposing metal stents for pancreatic fluid collection drainage: May not be business as usual?

We read with interest the paper by Bang et al 1 concerning their interim analysis of an ongoing randomised study comparing a novel fully covered self-expanding metal stent (fcSEMS) to plastic stents in patients undergoing endoscopic drainage of walled-off pancreatic necrosis (WOPN). This was following concerns over higher than expected adverse events in the fcSEMS (50%) compared with the plastic stent group (0%). Specifically, these adverse events were three cases of bleeding, two cases of buried stent and one case of biliary stricture. The three cases of bleeding were found to have pseudoaneurysms, which were treated by radiologically guided coiling. One of the buried stent cases developed severe bleeding on removal and requiring radiological intervention. The biliary stricture was managed endoscopically with fcSEMS removal and biliary …

Utility of cyst fluid CEA cut-off of 192ng/ml in the diagnosis of mucinous cysts of the pancreas

Introduction The differentiation of mucinous from non-mucinous pancreatic cysts is important because of the malignant potential of the latter. EUS-FNA allows for high resolution imaging of pancreatic cysts as well as sampling for markers (CEA), cytology and a visual assessment of cyst content. The Cooperative cyst study found an elevated fluid CEA (>192 ng/ml) to be the single most accurate test in correctly predicting mucinous cysts with a sensitivity of 73%. The CEA value of 192ng/ml has subsequently been widely adopted as a definitive cut-off value. Methods The aims of the present study were to assess the utility of a cut-off value of 192 ng/ml in differentiating mucinous from non-mucinous pancreatic cysts and to compare this to general EUS assessment. IPMN and mucinous cyst adenoma/adenocarcinoma (MCA and MCAC) were considered separately. The study population comprised all the patients undergoing EUS-FNA at a tertiary centre for assessment of suspected pancreatic neoplastic cysts between June 2003 and April 2010. Results During this period 267 procedures were performed on 235 individuals, of whom 71 had a definitive diagnosis (60 resection histology, 5 histology, 6 malignant cytology), cystic degeneration of pancreatic adenocarcinoma (3) being excluded. 68 patients (51 females), (78 procedures) formed the study group. There were 25 mucinous cyst adenomas (11 MCA, 14 MCAC). There were 22 IPMN (2 malignant) and 21 non-mucinous cysts. For MCA/MCAC using a cut-off of 192 ng/ml the sensitivity, specificity, accuracy and NPV of detecting a mucinous lesion were 62.5%, 94.4%, 79.4%, 73.9%. Combining EUS morphology, cytology and visual assessment of aspirate (mucoid/non-mucoid) gave figures of 100%, 70.8%, 86%, 100%. The combination was significantly more sensitive p=0.007, but no significant difference in specificity. ROC area under the curve was numerically greater 0.861 versus 0.785 (not significant). For the IPMN patients the cut-off 192 ng/ml showed a sensitivity of 20% in the diagnosis of IPMN. EUS diagnosis had a sensitivity of 85%. Sensitivity of aspirate appearance: 87%, cytology: 50%; combining fluid appearance, EUS and cytology: 93%. Comparing the performance of CEA 192 versus combination in differentiating IPMN from non-mucinous cyst, ROC curve area was 0.864 versus 0.623 p =0.02. Conclusion A CEA cut-off of 192 ng/ml demonstrated good specificity and moderate sensitivity in the diagnosis of MCA, however it performed poorly in the diagnosis of IPMN. Combining EUS, aspirate appearance and cytology was significantly more sensitive in diagnosing mucinous cysts with a very high NPV.