An internally covered (lined) self-expanding metal esophageal stent: tissue response in a porcine model.

BACKGROUND: Self-expandable metal stents (SEMS) palliate malignant dysphagia but may embed in tissue, produce granulation tissue, and prevent removal. OBJECTIVE: Our purpose was to evaluate in a porcine model the tissue response induced by a new esophageal SEMS completely coated internally rather than externally. DESIGN: Eight Yucatan pigs were studied. Each animal underwent placement of 2 stents: 1 study stent and 1 control stent. SEMS were placed proximally or distally by random assignment. Follow-up endoscopy was performed 1, 2, 3, and 4 weeks after implantation. Ease of stent removal was assessed at 2 weeks and 4 weeks after placement. SETTING: Animal laboratory. INTERVENTIONS: Endoscopic placement of study stents (Alveolus ES-STS, Alveolus, Inc, Charlotte, NC; 18 mm diameter, fully covered internally) and control stents (Ultraflex stent, Boston Scientific, Natick, Mass; microvasive, 18 mm midbody, subtotally covered externally). MAIN OUTCOME MEASUREMENTS: Extent of granulation tissue and stent-induced esophageal injury. RESULTS: The tissue hyperplasia response of the study stents was endoscopically graded as mild to moderate. All study stents were endoscopically removed easily and atraumatically. Control stents produced severe granulation tissue formation with complete embedding of the uncovered stent ends; endoscopic removal was possible but resulted in trauma and endoscopically visible bleeding. Histopathologic findings revealed minimal tissue response at the ends of the study stents and severe pseudopolyps in the embedded portion of the control stent. Stent migration occurred in 7 of 8 study stents and 4 of 8 control stents. LIMITATIONS: Animal model lacks stricture. CONCLUSIONS: Fully internally lined SEMS may resist tissue embedding and hyperplasia and may be removable. Human studies are needed to assess applicability to treatment of benign and malignant esophageal disease.

A prospective, randomized, double-blind, placebo-controlled trial of endoscopic steroid injection therapy for recalcitrant esophageal peptic strictures.

BACKGROUND AND AIMS: The aim of the study was to examine whether endoscopic intralesional corticosteroid injection into recalcitrant peptic esophageal strictures reduces the need for repeat stricture dilation. METHODS: Patients with a peptic esophageal stricture and recurrent dysphagia having had at least one dilation in the preceding 18 months were enrolled in a prospective randomized, double-blind study comparing steroid and sham injection. After endoscopic confirmation of recurrent stricture, patients were randomized to receive either 0.5 cc/quadrant triamcinolone (40 mg/cc) or sham injection into the stricture followed by balloon dilation of the stricture. Patients were stratified by the number of dilations required in the preceding 18 months, severity of dysphagia, the presence of esophagitis, stricture severity, and prior therapy with a proton-pump inhibitor. Patients and their physicians were blinded to the type of intervention received. Baseline dysphagia questionnaires were completed. Post-procedurally all patients were placed on a standardized proton-pump inhibitor regimen and standardized telephone follow-up questionnaires were completed at 1 wk and at 1, 3, 6, 9, and 12 months. The original sample-size calculation of 60 patients could not be met in a timely fashion because of a low incidence of recalcitrant peptic stricture patients. RESULTS: A total of 30 patients were enrolled, 15 in the steroid group (10 men, mean age 66 yr) and 15 in the sham group (11 M, mean age 67 yr). Patients were followed for 1 yr, unless they underwent an antireflux operation or died. Two patients, one per group, died of non-esophageal causes at 1 and 12 months. Four patients had fundoplication, two in each group, unrelated to stricture or dysphagia. Two patients in the steroid group (13%) and nine in the sham group (60%) required repeat dilation (p= 0.011). CONCLUSIONS: In patients with recalcitrant peptic esophageal stricture, steroid injection into the stricture combined with acid suppression significantly diminishes both the need for repeat dilation and the average time to repeat dilation compared to sham injection and acid suppression alone.

Prospective study of a Trucut needle for performing EUS-guided biopsy with EUS-guided FNA rescue.

BACKGROUND: EUS-guided FNA (EUS-FNA) is an accurate technique for sampling extraintestinal masses and lymph nodes. The use of a Trucut needle to perform EUS-guided biopsy (EUS-TCB) may improve the results or simplify the procedure. To date, few studies have prospectively assessed the performance and the safety of EUS-TCB. METHODS: Patients with a known or a suspected malignancy referred for a diagnostic and/or staging EUS examination were enrolled in a prospective study. EUS-guided biopsy was performed first with a 19-gauge Trucut needle. If the Trucut failed to obtain an adequate sample or when the "in room" touch preparation was benign, EUS-FNA was performed with a standard 22-gauge FNA needle. The objective of the study was to assess the yield of detection of malignancy and the safety of EUS-TCB in patients with known or suspected malignancies and to investigate if EUS-FNA has a role for rescue in cases of Trucut failure. OBSERVATIONS: Thirty-nine lesions underwent EUS-TCB in 30 patients. Sufficient follow-up was available for all patients. By using EUS-TCB, we were able to obtain a sample for diagnosis in all but 3 patients (one pancreatic mass and two lymph nodes) in which technical problems arose. In these patients, the diagnosis was obtained in two cases by EUS-FNA and in the other one by EUS-TCB from the primary pancreatic tumor. The yield of detection of malignancy for EUS-TCB was 84%. No complications were recorded in any patients at 1 and 7 days of follow-up. The sample size is limited to generalize conclusions. CONCLUSIONS: EUS-TCB is a safe and an accurate procedure to obtain a histologic diagnosis in patients with known or suspected malignancies. EUS-FNA can serve as a rescue technique in cases of Trucut failure.

Prospective, randomized, controlled trial of prophylactic pancreatic stent placement for endoscopic snare excision of the duodenal ampulla.

BACKGROUND: Tumors that arise in the region of the major duodenal papilla account for 5% of GI neoplasms and 36% of resectable pancreaticoduodenal tumors. There is limited published literature that addresses the safety of endoscopic excision of the papilla. Although there is consensus about prophylactic pancreatic-duct stent placement, there is little supporting prospective data. The aim of this randomized, controlled trial was to compare the rates of postsnare ampullectomy pancreatitis in patients who did/did not receive prophylactic pancreatic-duct stent placement. METHODS: Consecutive patients who were to undergo en bloc snare ampullectomy were randomized to placement of pancreatic-duct stent after ampullectomy or to no stent placement. RESULTS: In total, 19 patients were enrolled, and 10 received pancreatic stents. Postprocedure pancreatitis occurred in 3 patients in the 24 hours after endoscopy, all cases occurred in the unstented group, 33% vs. 0% (stented group), p = 0.02. Median peak amylase level was 3692 U/L (range 1819-4700 U/L) and median peak lipase level was 11450 U/L (range 5900-17,000 U/L). All 3 patients were hospitalized for a median of 2 days (range 1-6), and all made a complete recovery. CONCLUSIONS: Our findings suggest that a protective effect is conferred by pancreatic stent placement in reducing postampullectomy pancreatitis. Future large-scale studies are required to confirm this benefit.

A comparison of routine cytology and fluorescence in situ hybridization for the detection of malignant bile duct strictures.

BACKGROUND AND AIM: The aim of this study was to assess the relative sensitivities and specificities of fluorescence in situ hybridization (FISH) and routine cytology for the detection of malignancy in biliary tract strictures. METHODS: Bile duct brushing and aspirate specimens were collected from 131 patients being evaluated for possible malignant bile duct strictures. Both specimen types were assessed by FISH but only brushing specimens were assessed by cytology. The FISH assay used a mixture of fluorescently-labeled probes to the centromeres of chromosomes 3, 7, and 17 and chromosomal band 9p21 (Vysis UroVysion) to identify cells having chromosomal abnormalities. A case was considered positive for malignancy if five or more cells exhibited polysomy. RESULTS: Sixty-six of the 131 patients had surgical pathologic and/or clinical evidence of malignancy. Thirty-nine patients had cholangiocarcinoma, 19 had pancreatic carcinoma, and 8 had other types of malignancy. The sensitivity of cytology and FISH for the detection of malignancy in bile duct brushing specimens in these patients was 15% and 34% (p < 0.01), respectively. The sensitivity of FISH for the bile aspirate specimens was 23%, and the combined sensitivity of FISH for aspirate and brushing specimens was 35%. The specificity of FISH and cytology brushings were 91% and 98% (p= 0.06), respectively. CONCLUSIONS: FISH is significantly more sensitive than and nearly as specific as conventional cytology for the detection of malignant biliary strictures in biliary brushing specimens. FISH may improve the clinical management of patients who are being evaluated for malignancy in bile duct strictures.

A prospective comparison of digital image analysis and routine cytology for the identification of malignancy in biliary tract strictures.

BACKGROUND & AIMS: Digital image analysis (DIA) allows quantification of nuclear DNA content and may help distinguish benign and malignant strictures of the biliary tract. METHODS: One hundred ten consecutive patients undergoing endoscopic retrograde cholangiography for suspicious biliary tract strictures were enrolled in a prospective study comparing the accuracy of DIA and routine cytology (RC). Standard brush cytology sampling was performed twice by using 2 cytology brushes per patient. Both brushes were fixed in a single-specimen vial. Each specimen was formed into 1 pellet, and the sample was equally divided for evaluation by DIA and RC. DNA histograms were generated for ploidy analysis. The DIA criterion for malignancy was demonstration of aneuploidy. RESULTS: Two patients had inadequate samples obtained for DIA analysis, 7 benign patients were excluded because of inadequate follow-up of less than 75 days, and 1 patient was lost to follow-up to clarify malignant versus benign disease. Of the remaining 100 patients, 56 strictures were malignant and 44 were benign. The sensitivities of DIA and RC were 39.3% and 17.9%, respectively (P = 0.014). The specificities of DIA and RC were 77.3% and 97.7%, respectively (P = 0.003). The accuracy of DIA (56.0%) was equivalent to RC (53.0%). CONCLUSIONS: DIA is a valuable adjunct to RC for detecting malignant strictures of the biliary tract.