Paul Yeaton

Temple University, Philadelphia, Pennsylvania, United States

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Publications (94)281.47 Total impact

  • Jennifer Maranki, Paul Yeaton
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    ABSTRACT: Pancreatitis is one of the most common complications of endoscopic retrograde cholangiopancreatography (ERCP). A variety of patient-related and procedure-related factors have been identified to risk-stratify patients. Several measures can be undertaken in order to decrease the risk of post-ERCP pancreatitis in high-risk groups. These measures include pancreatic duct stenting and rectal indomethacin, amongst others.
    Current Gastroenterology Reports 11/2013; 15(11):352.
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    ABSTRACT: C-X-C ligand (CXCL) chemokines exert major roles in the biologic aggressiveness of esophageal cancer. In the current study, the authors investigated temozolomide (TMZ)-induced effects on activity of the CXCL chemokine network in human esophageal cancer cells. To the authors' knowledge, TMZ has not been investigated previously in experimental or clinical esophageal cancers. A complete mapping of CXCL chemokines and their receptor messenger RNA was performed in 2 established human esophageal cancer cell lines (OE21 and OE33) and in 4 surgical samples from patients with esophageal carcinoma. The analyses pointed out the potential importance of CXCL2, and monitoring CXCL2 with quantitative videomicroscopy indicated that its biologic activity was silenced in OE21 esophageal cancer cells. TMZ-mediated antitumor activity was determined in vivo in an OE21 metastatic nude mice xenograft model. The messenger RNA levels of CXC chemokines and their receptors were similar in both cell lines and in the 4 surgical specimens. CXCL2 depletion by small interfering RNA (siRNA) displayed marked effects on the proliferation of transfected OE21 cells. Chronic in vitro TMZ treatment of OE21 and OE33 cells markedly decreased CXCL2 and CXCL3 secretion. In vivo, TMZ induced significant delays in OE21 xenograft tumor development and improved the survival of OE21 xenograft-bearing mice, whereas cisplatin did not. Analyses performed on tissue samples from in vivo experiments revealed that TMZ also impaired tumor angiogenesis. The current study emphasized the role of proangiogenic chemokines in esophageal cancer biology and indicated the possibility of using TMZ as a clinically compatible drug to impair the actions of the CXCL chemokine network in esophageal cancers.
    Cancer 05/2011; 117(9):2004-16. · 5.20 Impact Factor
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2011; 73(4).
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    ABSTRACT: The electrosurgical knives required to perform endoscopic submucosal dissection (ESD) have recently passed the 510(k) premarketing evaluation by the U.S. Food and Drug Administration and are now available for purchase in the United States. Challenges to ESD being more widely performed in the United States include the lack of intensive hands-on training programs and a low incidence of appropriate, highly dysplastic gastric lesions on which an ESD-trained endoscopist can begin performing this procedure in patients. Furthermore, there are no guidelines regarding the safety of continuing antiplatelet therapy in patients undergoing ESD. To report on the first gastric ESD performed in the United States by using recently approved electrosurgical knives on a patient who was maintained on aspirin therapy. Case report. Large academic medical center. One patient with a 2-cm high-grade dysplasia (HGD) lesion in the posterior antrum who had indwelling coronary stents and was maintained on aspirin therapy throughout the periprocedural period. High-definition white-light and narrow-band imaging endoscopy, endosonography, and ESD by using recently approved electrosurgical knives. Complete resection of the HGD gastric lesion. En bloc complete resection of the HGD gastric lesion was achieved without any immediate or delayed bleeding or perforation. No residual or recurrent dysplasia was found on 1- or 3-month follow-up endoscopies. Generalizations cannot be made from this single case. After receiving intensive hands-on training in both ex vivo and in vivo animal models, gastric ESD was successfully performed by 2 U.S. endoscopists by using recently approved electrosurgical knives in a patient maintained on aspirin therapy without any complications.
    Gastrointestinal endoscopy 11/2010; 72(5):1066-71. · 6.71 Impact Factor
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    ABSTRACT: The presence of meshed capillary (MC) vessels is highly sensitive (96%) and specific (92%) for diagnosing colorectal neoplasia on colonoscopy by using narrow-band imaging (NBI) with optical magnification, which is not available in North America. However, the efficacy of NBI to identify an MC pattern without optical magnification has not been determined. To determine the diagnostic capabilities of NBI colonoscopy without optical magnification in differentiating neoplastic from non-neoplastic colorectal polyps by using the MC pattern. Retrospective comparison of prospectively collected colorectal polyp data. Large, academic medical center. This study involved 126 consecutive colorectal polyps (median size 3 mm) that were found in 52 patients (33 men) with a median age of 59.5 years. All lesions identified by white-light colonoscopy were prospectively diagnosed in real-time by using the MC pattern as determined on high-definition NBI, with 1.5x zoom but without true optical magnification, and then endoscopically excised. Surgical pathology was used as the criterion standard. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of identifying neoplastic polyps were calculated. NBI without optical magnification was found to have a sensitivity of 93%, specificity of 88%, positive predictive value of 90%, negative predictive value of 91%, and diagnostic accuracy of 91% when all polyp sizes were considered. For lesions < or =5 mm, sensitivity was 87%, specificity was 93%, positive predictive value was 89%, negative predictive value was 91%, and diagnostic accuracy was 90%. Single-center, single-endoscopist experience. Use of the MC pattern on NBI colonoscopy without optical magnification effectively distinguishes neoplastic from non-neoplastic colorectal polyps. NBI colonoscopy without optical magnification for neoplastic polyp diagnosis appears to be comparable with NBI with optical magnification when the MC pattern is used. A large, prospective trial is needed for further validation.
    Gastrointestinal endoscopy 04/2010; 72(1):118-26. · 6.71 Impact Factor
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2010; 71(5).
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2010; 71(5).
  • The American journal of medicine 03/2009; 122(2):e3-4. · 5.30 Impact Factor
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2009; 69(5).
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2009; 69(5).
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    ABSTRACT: Unresectable cholangiocarcinoma is an intractable disease marked by recurrent bouts of biliary obstruction and infection. Traditional treatment methods provide only symptomatic relief and no proven survival advantage. We assessed the tolerability of helical tomotherapy intensity modulated radiotherapy (IMRT) with concurrent capecitabine and photodynamic therapy (PDT) in patients with unresectable hilar cholangiocarcinoma. Ten patients with unresectable hilar cholangiocarcinoma were treated with helical tomotherapy IMRT. An accelerated dose of 50 Gy in 20 fractions (2.5 Gy/fraction) was used. Planning target volume (PTV) consisted of a 1.5 cm radial expansion and a 2 cm craniocaudal expansion of the magnetic resonance imaging and/or contrast enhanced computed tomography-defined gross target volume. PTV ranged from 123 cc to 693 cc (mean 349 cc). Concurrent chronomodulated capecitabine was administered on days of irradiation. Six patients received PDT. All patients developed side effects, including grade 2 nausea, and 9 of 10 experienced mild fatigue. Patients lost 3% of their body weight on average. Three patients required brief hospital admission and stent revision for cholangitis during chemoradiotherapy. Capecitabine was discontinued in one patient and decreased in dose for another due to increasing liver enzymes. Median overall survival was 13 months, and median disease-free survival was 10 to 11 months. One patient underwent successful cadaveric liver transplant after chemoradiotherapy and remains disease free 2 years later. Concurrent chemoradiotherapy with helical tomotherapy IMRT and capecitabine in conjunction with PDT is well tolerated in patients with hilar cholangiocarcinoma.
    Gastrointestinal cancer research: GCR 10/2008; 2(5):219-24.
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    ABSTRACT: Pseudocyst development is a common complication of chronic pancreatitis. Endoscopic cystogastrostomy is an alternative to percutaneous drainage of pancreatic pseudocysts. Endoscopic ultrasound (EUS) guidance is thought to decrease the procedural risk by identifying and avoiding intervening vasculature. With EUS guidance, extreme care should be exercised to identify large gastric vessels in the path of the puncture. Preoperative imaging should be closely scrutinized for the presence of these vessels. In cases of hemorrhage, balloon tamponading is a rapid way to provide temporary control, allowing transfer of the patient for angiographic embolization. We present a case of arterial hemorrhage due to inadvertent puncture of a hypertrophied right gastric artery following EUS-guided cystogastrostomy, which was successfully treated with temporary balloon occlusion and coil embolization.
    Diagnostic and interventional radiology (Ankara, Turkey) 04/2008; 14(1):57-60. · 1.03 Impact Factor
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    ABSTRACT: Benign biliary strictures (BBS) are usually managed with plastic stents, whereas placement of uncovered metallic stents has been associated with failure related to mucosal hyperplasia. We analyzed the efficacy and safety of temporary placement of a covered self-expanding metal stent (CSEMS) in BBS. Patients with BBS received temporary placement of CSEMSs until adequate drainage was achieved; confirmed by resolution of symptoms, normalization of liver function tests, and imaging. Tertiary-care center with long-standing experience with CSEMSs. Seventy-nine patients with BBS secondary to chronic pancreatitis (32), calculi (24), liver transplant (16), postoperative biliary repair (3), autoimmune pancreatitis (3), and primary sclerosing cholangitis (1). ERCP with temporary CSEMS placement. Removal of CSEMSs was performed with a snare or a rat-tooth forceps. End points were efficacy, morbidity, and clinical response. CSEMSs were removed from 65 patients. Resolution of the BBS was confirmed in 59 of 65 patients (90%) after a median follow-up of 12 months after removal (range 3-26 months). If patients who were lost to follow-up, developed cancer, or expired were considered failures, then an intent-to-treat global success rate of 59 of 79 (75%) was obtained. Complications associated with placement included 3 post-ERCP pancreatitis (4%), 1 postsphincterotomy bleed (1%), and 2 pain that required CSEMS removal (2%). In 11 patients (14%), the CSEMS migrated. In 1 patient, CSEMS removal was complicated by a bile leak that was successfully managed with plastic stents. Pilot study from a single center. Temporary CSEMS placement in patients with BBS offers a potential alternative to surgery.
    Gastrointestinal Endoscopy 04/2008; 67(3):446-54. · 5.21 Impact Factor
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    ABSTRACT: Photodynamic therapy (PDT) for unresectable cholangiocarcinoma is associated with improvement in cholestasis, quality of life, and potentially survival. We compared survival in patients with unresectable cholangiocarcinoma undergoing endoscopic retrograde cholangiopancreatography (ERCP) with PDT and stent placement with a group undergoing ERCP with stent placement alone. Forty-eight patients were palliated for unresectable cholangiocarcinoma during a 5-year period. Nineteen were treated with PDT and stents; 29 patients treated with biliary stents alone served as a control group. Multivariate analysis was performed by using Model for End-Stage Liver Disease score, age, treatment by chemotherapy or radiation, and number of ERCP procedures and PDT sessions to detect predictors of survival. Kaplan-Meier analysis demonstrated improved survival in the PDT group compared with the stent only group (16.2 vs 7.4 months, P<.004). Mortality in the PDT group at 3, 6, and 12 months was 0%, 16%, and 56%, respectively. The corresponding mortality in the stent group was 28%, 52%, and 82%, respectively. The difference between the 2 groups was significant at 3 months and 6 months but not at 12 months. Only the number of ERCP procedures and number of PDT sessions were significant on multivariate analysis. Adverse events specific to PDT included 3 patients with skin phototoxicity requiring topical therapy only. ERCP with PDT seems to increase survival in patients with unresectable cholangiocarcinoma when compared with ERCP alone. It remains to be proved whether this effect is attributable to PDT or the number of ERCP sessions. A prospective randomized multicenter study is required to confirm these data.
    Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association 03/2008; 6(3):290-7. · 5.64 Impact Factor
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    ABSTRACT: Bilomas have traditionally been treated by either percutaneous drainage or surgery. However, percutaneous drainage is associated with discomfort and infection, whereas surgery, which is usually reserved for refractory cases, has high morbidity and mortality rates. Recently, endoscopic drainage of bilomas adjacent to the GI lumen has been reported in isolated reports. We analyzed our 4 years' experience with this innovative technique. Patients with symptomatic bilomas were offered EUS-guided drainage and were followed up prospectively for clinical and radiologic responses. Tertiary care center with long-standing experience in EUS-guided drainage. A total of 5 patients underwent EUS-guided transenteric drainage of symptomatic bilomas. The technique included transenteric EUS-guided puncture, placement of a guidewire into the biloma, and creation of an enteral-biloma fistula with placement of a plastic endoprosthesis after balloon dilation. In 4 cases, the stents were removed at a mean of 6.8 +/- 4.3 weeks. In one patient with malignancy, the stent was left in place for palliation. Efficacy and safety of EUS-guided drainage of bilomas. EUS-guided transenteric biloma drainage was successfully performed in 5 patients without any significant morbidity. Biloma resolution was confirmed in all 5 patients, and none of the 4 patients relapsed after stent removal (mean follow-up of 12.8 +/- 6.1 months). EUS-guided drainage of bilomas is technically feasible, appears safe, and provides an attractive alternative to percutaneous or surgical drainage.
    Gastrointestinal Endoscopy 02/2008; 67(1):136-40. · 5.21 Impact Factor
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2008; 67(5).
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2008; 67(5).
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2008; 67(5).
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    ABSTRACT: Management of biliary leaks includes ERCP and stent placement. The ability to temporarily place a partially covered self-expandable metallic stent (CSEMS) might offer an advantage in the treatment of biliary leaks. We analyzed our 2 years' experience when using this innovative technique. Patients in whom a previous ERCP had failed to resolve a bile leak or patients with severe comorbidities were offered CSEMS and were followed prospectively for clinical and radiologic responses. Tertiary-care center with long-standing experience of using CSEMS. A total of 16 patients were included. Of these, 7 had previously undergone unsuccessful plastic stent placement, 3 had previously failed ERCP, and 7 had severe comorbidities that prevented multiple interventions. ERCP with placement of a CSEMS covering the cystic duct take-off in the case of a cystic-stump leak. CSEMS were removed after resolution of the leak. Efficacy and safety of the CSEMS in bile leaks; complications were also evaluated. Of the patients studied, 15 responded to CSEMS placement with complete resolution of the leak on imaging. One patient with partial cholecystectomy relapsed and underwent drainage; another patient responded to the treatment but required revision because of migration. CSEMS were left in place for a median time of 3 months (range, 1-17 months). Complications included 1 proximal and 1 distal migration. Pilot study from a single center. CSEMS is an excellent option in this subgroup of patients not responding to plastic stent placement or with severe comorbidities.
    Gastrointestinal Endoscopy 08/2007; 66(1):52-9. · 5.21 Impact Factor
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    ABSTRACT: Characterization of pancreatic cysts using endoscopic ultrasound-guided fine-needle aspiration includes cytological interpretation and chemical analysis. We prospectively analyzed the contribution of carcinoembryonic antigen (CEA) and cytological identification of extracellular mucin as predictors of mucinous neoplasia and malignancy. From January 2003 to October 2005, all patients referred to the University of Virginia with cystic lesions of the pancreas underwent endoscopic ultrasound-guided fine-needle aspiration with cytological evaluation and CEA level analysis. Data were collected prospectively and confirmed by resection or tissue biopsy. Univariate and multivariate analyses were performed on the following variables with regard to their ability to predict mucinous neoplasia: age (<55 or >55 years), sex, CEA level (<300 or >300 ng/mL), and cytological appreciation of extracellular mucin (positive or negative). P values less than 0.05 were considered significant. A total of 43 patients were included in this study. There were 19 men and 24 women with a mean age of 63 +/- 14 years. The only complication was pancreatitis secondary to cyst leak in one patient. Multivariate analysis confirmed CEA level greater than 300 ng/mL (P= 0.007) and the identification of mucin (P < 0.001) as significant predictors. With pancreatic cyst fluid analysis, the strongest predictor of mucinous neoplasia is the presence of identifiable mucin, followed by a CEA level greater than 300 ng/mL. The workup of cystic lesions of the pancreas should include chemical analysis for the CEA level and cytological examination with particular attention to extracellular mucin.
    Pancreas 05/2007; 34(4):466-9. · 2.95 Impact Factor

Publication Stats

1k Citations
281.47 Total Impact Points

Institutions

  • 2013
    • Temple University
      Philadelphia, Pennsylvania, United States
  • 1996–2009
    • University of Virginia
      • • Department of Medicine
      • • Digestive Health Research Center
      • • Division of Gastroenterology and Hepatology
      Charlottesville, VA, United States
  • 1997–2003
    • Université Libre de Bruxelles
      • Faculty of Medicine
      Brussels, BRU, Belgium