John M. Poneros

A randomized trial comparing uncovered and partially covered self- expandable metal stents in the palliation of distal malignant biliary obstruction

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.

EUS-guided fine needle aspiration of pancreatic cysts: A retrospective analysis of complications and their predictors

BACKGROUND AND AIMS Endoscopic ultrasound-guided fine-needle aspiration (EUS FNA) of pancreatic cysts is considered safe, however, data are conflicting regarding complication rates. The aim of this study was to determine the complication rate of EUS-guided pancreatic cyst aspiration and predictors of these complications. METHODS Results of pancreatic cyst EUS FNA at 2 academic institutions from March 1996 to October 2003 were reviewed. A total of 603 patients with 651 pancreatic cysts were evaluated. Complications were identified from clinic, emergency department, and discharge notes, and laboratory and radiologic data. Data collected were as follows: cyst size, location, septations, diagnosis, number of passes, needle size, status as inpatient or outpatient, performance of same-day endoscopic retrograde cholangiopancreatography (ERCP), and use of prophylactic antibiotics. RESULTS Complications were identified in 13 patients (2.2%, 13 of 603): 6 patients had pancreatitis, 4 patients had abdominal pain, 1 patient had a retroperitoneal bleed, 1 patient had an infection, and 1 patient had bradycardia. Twelve patients required hospitalization, with an average length of stay of 3.8 +/- 1.1 days. Type of cyst, size, presence of septations or mass, and same-day ERCP were not predictors of complications. CONCLUSIONS EUS-guided pancreatic cyst aspiration carries a low complication rate similar to that reported for solid pancreatic lesions. No patient or cyst characteristics appear to be predictive of adverse events.

Diagnosis of Barrett's esophagus using optical coherence tomography.

OCT is a promising optical technology that permits real-time, high-resolution, cross-sectional imaging of tissue during endoscopy. It has been shown to be a highly sensitive and specific means of identifying the presence of SIM. Preliminary studies suggest that OCT is capable of grading dysplasia occurring within BE and has the potential to assist with the staging of superficial malignancies, particularly squamous cell cancers. In the near future, the capabilities of OCT systems are expected to improve with systems capable of much higher resolution and with Doppler capability becoming available.

Detection of high-grade dysplasia in Barrett's esophagus by spectroscopy measurement of 5-aminolevulinic acid-induced protoporphyrin IX fluorescence.

BACKGROUND Preliminary studies with qualitative detection methods suggest that 5-aminolevulinic acid-induced protoporphyrin IX fluorescence might improve the detection of dysplastic Barretts epithelium. This study used quantitative methods to determine whether aminolevulinic acid-induced protoporphyrin IX fluorescence can differentiate between Barretts mucosa with and without dysplasia. METHODS Patients were given 10 mg/kg of aminolevulinic acid orally 3 hours before endoscopy. Quantitative fluorescence spectra were acquired by using a nitrogen-pumped dye laser (l 400 nm) spectrograph system. The protoporphyrin IX fluorescence intensity at 635 nm was compared with the histopathologic diagnosis for mucosal biopsy specimens taken immediately after the fluorescence measurements. RESULTS Ninety-seven spectra were obtained from 20 patients. The mean (+/- standard error) standardized protoporphyrin IX fluorescence intensity was significantly greater (p < 0.05) for high-grade dysplastic Barretts epithelium (0.29 +/- 0.07, n = 13) than for nondysplastic Barretts epithelium (0.11 +/- 0.02, n = 43). By using protoporphyrin IX fluorescence alone, high-grade dysplasia was distinguished from nondysplastic tissue types with 77% sensitivity and 71% specificity. Decreased autofluorescence was particularly found in nodular high-grade dysplasia. By using the fluorescence intensity ratio of 635 nm/480 nm, nodular high-grade dysplasia could be differentiated from nondysplastic tissue with 100% sensitivity and 100% specificity. CONCLUSION Protoporphyrin IX fluorescence may be useful for identifying areas of high-grade dysplasia in Barretts esophagus and for targeting of biopsies.

EUS-guided portal vein catheterization and pressure measurement in an animal model: a pilot study of feasibility

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.

Multicenter trial evaluating the use of covered self-expanding metal stents in benign biliary strictures: time to revisit our therapeutic options?

Background: Covered self-expanding metal stents are being used more frequently in benign biliary strictures (BBS). We report the results of a multicenter study with fully covered self-expanding metal stent (FCSEMS) placement for the management of BBS. Aim: To prospectively evaluate the efficacy and safety of FCSEMS in the management of BBS. Patients and Methods: Patients with BBS from 6 tertiary care centers who received FCSEMS with flared ends between April 2009 and October 2010 were included in this retrospective study. Efficacy was measured after removal of FCSEMS by evaluating stricture resolution on the basis of symptom resolution, imaging, laboratory studies, and/or choledochoscopy at removal. Safety profile was evaluated by assessing postprocedural complications. Results: A total of 133 patients (78, 58.6% males) with a mean age of 59.2±14.8 years with BBS received stents. Of the 133 stents placed, 97 (72.9%) were removed after a mean stent duration of 95.5±48.7 days. Stricture resolution after FCSEMS removal was as follows: postsurgical, 11/12 (91.6%); gallstone-related disease, 16/19 (84.2%); chronic pancreatitis, 26/31 (80.7%); other etiology, 4/5 (80.0%); and anastomotic strictures, 19/31(61.2%). Ninety-four patients were included in the logistic regression analyses. Patients who had indwelling stents for >90 days were 4.3 times more likely to have resolved strictures [odds ratio, 4.3 (95% confidence interval, 1.24-15.09)] and patients with nonmigrated stents were 5.4 times more likely to have resolved strictures [odds ratio, 5.4 (95% confidence interval, 1.001-29.29)]. Conclusions: FCSEMS for BBS had an acceptable rate of stricture resolution for postsurgical strictures, gallstone-related strictures, and those due to chronic pancreatitis. Predictors for stricture resolution include longer indwell time and absence of migration. Further study is warranted to assess long-term efficacy in a prospective manner with longer than 3-month time of stent indwelling time.

Fine‐needle aspirations of pancreatic serous cystadenomas: Improving diagnostic yield with cell blocks and α‐inhibin immunohistochemistry

The diagnosis of serous cystadenoma (SCA), a rare benign pancreatic neoplasm, can alter the management of patients with pancreatic masses. Although characteristic imaging findings and fluid chemical analysis have been described, SCAs are not always recognized preoperatively. Furthermore, scant cellular yield on fine‐needle aspiration (FNA) often leads to a nondiagnostic or nonspecific benign diagnosis. α‐Inhibin (AI), a sensitive marker for SCA, is infrequently required for diagnosis in surgical specimens due to their characteristic histologic appearance. The objective of the current study was to determine whether AI staining can improve SCA diagnosis on FNA specimens.

Fully covered self-expandable metal stents for benign esophageal disease: a multicenter retrospective case series of 31 patients

failure to thrive, aspiration causing recurrent pneumonia, upper respiratory tract infection, and food or foreign-body impaction.7,8 Esophagography was the primary diagnostic tool and was performed in all patients (Fig. 5). The esophagography results showed segmental stenosis at the distal third of the esophagus in all patients except 1. Esophagoscopy was performed in most patients and usually showed a nonspecific distal esophageal stenosis without inflammation. Repeated dilation of the stricture was performed in 33 patients, resulting in only transient or no relief of dysphagia. Three patients had esophageal perforation after dilation, with 1 death after a single dilation. In most of the patients, definitive treatment was performed between 1 and 3 months of age, and surgical resection was required. The diagnosis of TBRs (57 patients) could only be made by histopathological examination of the resected segment, thus underscoring the importance of EUS in the preoperative diagnosis of TBRs.

Endoscopic suturing for the prevention of stent migration in benign upper gastrointestinal conditions: a comparative multicenter study

BACKGROUND AND STUDY AIMS Fully covered self-expandable metal stents (FCSEMSs) have increasingly been used in benign upper gastrointestinal (UGI) conditions; however, stent migration remains a major limitation. Endoscopic suture fixation (ESF) may prevent stent migration. The aims of this study were to compare the frequency of stent migration in patients who received endoscopic suturing for stent fixation (ESF group) compared with those who did not (NSF group) and to assess the impact of ESF on clinical outcome. PATIENTS AND METHODS This was a retrospective study of patients who underwent FCSEMS placement for benign UGI diseases. Patients were divided into either the NSF or ESF group. Outcome variables, including stent migration, clinical success (resolution of underlying pathology), and adverse events, were compared. RESULTS A total of 125 patients (44 in ESF group, 81 in NSF group; 56 benign strictures, 69 leaks/fistulas/perforations) underwent 224 stenting procedures. Stent migration was significantly more common in the NSF group (33 % vs. 16 %; P = 0.03). Time to stent migration was longer in the ESF group (P = 0.02). ESF appeared to protect against stent migration in patients with a history of stent migration (adjusted odds ratio [OR] 0.09; P = 0.002). ESF was also significantly associated with a higher rate of clinical success (60 % vs. 38 %; P = 0.03). Rates of adverse events were similar between the two groups. CONCLUSIONS Endoscopic suturing for stent fixation is safe and associated with a decreased migration rate, particularly in patients with a prior history of stent migration. It may also improve clinical response, likely because of the reduction in stent migration.

Strategies for improving diagnostic accuracy of biliary strictures

Brush cytology is the initial intervention when evaluating biliary strictures. Biliary brush cytology is known for its low sensitivity (but high specificity) and may be accompanied by biopsies and/or fluorescent in situ hybridization (FISH) to improve diagnostic yield. This study aimed to identify features to enhance cytological sensitivity, and assess which sampling method(s) improve identification of pancreatobiliary adenocarcinomas (PBCa).