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Dive into the research topics where Peter D. Stevens is active.

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Featured researches published by Peter D. Stevens.


Gastrointestinal Endoscopy | 2004

EUS-guided trucut needle biopsies in patients with solid pancreatic masses: a prospective study

Alberto Larghi; Elizabeth C. Verna; Stavros N. Stavropoulos; Heidrun Rotterdam; Charles J. Lightdale; Peter D. Stevens

BACKGROUND A trucut needle biopsy device that can be used to obtain specimens from the pancreas and other perigastric organs under EUS guidance has been developed and successfully tested in animals. Moreover, EUS-guided trucut needle biopsy has been used safely in humans and appears to provide more accurate results than EUS-guided FNA. This study prospectively assessed the clinical utility of this new device in patients with solid pancreatic masses. METHODS Twenty-three consecutive patients with radiologically detected solid pancreatic masses underwent EUS-guided trucut needle biopsy. Pancreatic malignancy detected by EUS-guided trucut needle biopsy was considered a definitive diagnosis. Further diagnostic procedures and clinical course were used to establish or exclude the presence of malignancy in all other patients. RESULTS Pancreatic tissue was obtained in 17 of the 23 patients (74%), including all patients in whom the transgastric approach was used. No acute or long-term complication was observed. Histopathologic evaluation revealed pancreatic cancer in 12 patients. CT-guided biopsy specimens were obtained in 4 of the 5 patients with a negative EUS-guided trucut needle biopsy result; two were positive for adenocarcinoma. Overall diagnostic accuracy was 61%. Subgroup analysis of the 16 patients in whom EUS-guided trucut needle biopsy was successful and who were available for follow-up revealed a diagnostic accuracy of 87.5%. CONCLUSIONS This prospective study demonstrates that EUS-guided trucut needle biopsy, when performed transgastrically, is safe and accurate in the evaluation of patients with solid pancreatic masses.


Gastrointestinal Endoscopy | 2011

Single-operator cholangioscopy in patients requiring evaluation of bile duct disease or therapy of biliary stones (with videos)

Yang K.Yang Chen; Mansour A. Parsi; Kenneth F. Binmoeller; Robert H. Hawes; Douglas K. Pleskow; Adam Slivka; Oleh Haluszka; Bret T. Petersen; Stuart Sherman; Jacques Devière; Søren Meisner; Peter D. Stevens; Guido Costamagna; Thierry Ponchon; Joyce Peetermans; Horst Neuhaus

BACKGROUND The feasibility of single-operator cholangioscopy (SOC) for biliary diagnostic and therapeutic procedures was previously reported. OBJECTIVE To confirm the utility of SOC in more widespread clinical use. DESIGN Prospective clinical cohort study. SETTING Fifteen endoscopy referral centers in the United States and Europe. PATIENTS Two hundred ninety-seven patients requiring evaluation of bile duct disease or biliary stone therapy. INTERVENTIONS SOC examination and, as indicated, SOC-directed stone therapy or forceps biopsy. MAIN OUTCOME MEASUREMENTS Procedural success defined as ability to (1) visualize target lesions and, if indicated, collect biopsy specimens adequate for histological evaluation or (2) visualize biliary stones and initiate fragmentation and removal. RESULTS The overall procedure success rate was 89% (95% CI, 84%-92%). Adequate tissue for histological examination was secured in 88% of 140 patients who underwent biopsy. Overall sensitivity in diagnosing malignancy was 78% for SOC visual impression and 49% for SOC-directed biopsy. Sensitivity was higher (84% and 66%, respectively) for intrinsic bile duct malignancies. Diagnostic SOC procedures altered clinical management in 64% of patients. Procedure success was achieved in 92% of 66 patients with stones and complete stone clearance during the study SOC session in 71%. The incidence of serious procedure-related adverse events was 7.5% for diagnostic SOC and 6.1% for SOC-directed stone therapy. LIMITATIONS The study was observational in design with no control group. CONCLUSIONS Evaluation of bile duct disease and biliary stone therapy can be safely performed with a high success rate by using the SOC system.


Clinical Cancer Research | 2010

Pancreatic Cancer Screening in a Prospective Cohort of High-Risk Patients: A Comprehensive Strategy of Imaging and Genetics

Elizabeth C. Verna; Caroline Hwang; Peter D. Stevens; Heidrun Rotterdam; Stavros N. Stavropoulos; Carolyn Sy; Martin A. Prince; Wendy K. Chung; Robert L. Fine; John A. Chabot; Harold Frucht

Purpose: Pancreatic cancer is a virtually uniformly fatal disease. We aimed to determine if screening to identify curable neoplasms is effective when offered to patients at high risk. Experimental Design: Patients at high risk of pancreatic cancer were prospectively enrolled into a screening program. Endoscopic ultrasound (EUS), magnetic resonance imaging (MRI), and genetic testing were offered by a multidisciplinary team according to each patients risk. Results: Fifty-one patients in 43 families were enrolled, with mean age of 52 years, 35% of whom were male. Of these patients, 31 underwent EUS and 33 MRI. EUS revealed two patients with pancreatic cancer (one resectable, one metastatic), five with intraductal papillary mucinous neoplasms (IPMN), seven with cysts, and six with parenchymal changes. Five had pancreatic surgery (one total pancreatectomy for pancreatic cancer, three distal and one central pancreatectomy for pancreatic intraepithelial neoplasia 2 and IPMN). A total of 24 (47%) had genetic testing (19 for BRCA1/2 mutations, 4 for CDKN2A, 1 for MLH1/MSH2) and 7 were positive for BRCA1/2 mutations. Four extrapancreatic neoplasms were found: two ovarian cancers on prophylactic total abdominal hysterectomy and bilateral salpingo-oophorectomy, one carcinoid, and one papillary thyroid carcinoma. Overall, 6 (12%) of the 51 patients had neoplastic lesions in the pancreas and 9 (18%) had neoplasms in any location. All were on the initial round of screening. All patients remain alive and without complications of screening. Conclusions: Pancreatic cancer screening for high-risk patients with a comprehensive strategy of imaging and genetics is effective and identifies curable neoplasms that can be resected. Ongoing study will better define who will benefit from screening and what screening strategy will be the most effective. Clin Cancer Res; 16(20); 5028–37. ©2010 AACR.


Gastrointestinal Endoscopy | 2011

Direct visualization of indeterminate pancreaticobiliary strictures with probe-based confocal laser endomicroscopy: a multicenter experience.

Alexander Meining; Yang K. Chen; Douglas K. Pleskow; Peter D. Stevens; Raj J. Shah; Ram Chuttani; Joel E. Michalek; Adam Slivka

BACKGROUND Because of the low sensitivity of current ERCP-guided tissue sampling methods, management of patients with indeterminate pancreaticobiliary strictures is a challenge. Probe-based confocal laser endomicroscopy (pCLE) enables real-time microscopic visualization of strictures during an ongoing ERCP. OBJECTIVE To document the utility, performance, and accuracy of real-time pCLE diagnosis compared with histopathology. DESIGN Prospective observational study within the framework of a multicenter registry. SETTING Five academic centers. PATIENTS This study involved 102 patients with indeterminate pancreaticobiliary strictures. INTERVENTION Clinical information, ERCP findings, tissue sampling results, and pCLE videos were collected prospectively. Investigators were asked to provide a presumptive diagnosis based on pCLE during the procedure before pathology results were available. All patients received at least 30 days of follow-up until definitive diagnosis of malignancy was established or 1-year follow-up if index tissue sampling was benign. MAIN OUTCOME MEASUREMENTS Diagnostic accuracy, sensitivity, specificity of ERCP-guided pCLE compared with ERCP with tissue acquisition. RESULTS There were no pCLE-related adverse events in the study. We were able to evaluate 89 patients, of whom 40 were proven to have cancer. The sensitivity, specificity, positive-predictive value, and negative-predictive value of pCLE for detecting cancerous strictures were 98%, 67%, 71%, and 97%, respectively, compared with 45%, 100%, 100%, and 69% for index pathology. This resulted in an overall accuracy of 81% for pCLE compared with 75% for index pathology. Accuracy for combination of ERCP and pCLE was significantly higher compared with ERCP with tissue acquisition (90% vs 73%; P = .001). LIMITATIONS Investigators had access to all relevant clinical information, which may have biased the predictive characteristics of pCLE. CONCLUSION Probe-based CLE provides reliable microscopic examination and has excellent sensitivity and negative predictive value. The significantly higher accuracy of ERCP and pCLE compared with ERCP with tissue acquisition may support supplementing ERCP with pCLE.


Gastrointestinal Endoscopy | 2013

A multicenter, U.S. experience of single-balloon, double-balloon, and rotational overtube–assisted enteroscopy ERCP in patients with surgically altered pancreaticobiliary anatomy (with video)

Raj J. Shah; Maximiliano Smolkin; Roy D. Yen; Andrew S. Ross; Richard A. Kozarek; Douglas A. Howell; Gennadiy Bakis; Sreenivasan S. Jonnalagadda; Abed Al-Lehibi; Al Hardy; Douglas R. Morgan; Amrita Sethi; Peter D. Stevens; Paul Akerman; Shyam Thakkar; Brian C. Brauer

BACKGROUND Data on overtube-assisted enteroscopy to facilitate ERCP in patients with surgically altered pancreaticobiliary anatomy, or long-limb surgical bypass, is limited. OBJECTIVE To evaluate and compare ERCP success by using single-balloon (SBE), double-balloon (DBE), or rotational overtube enteroscopy. DESIGN Consecutive patients identified retrospectively. SETTING Eight U.S. referral centers. PATIENTS Long-limb surgical bypass patients with suspected pancreaticobiliary diseases. INTERVENTION Overtube-assisted enteroscopy ERCP. MAIN OUTCOME MEASUREMENTS Enteroscopy success: visualizing the pancreaticobiliary-enteric anastomosis or papilla. ERCP success: completing the intended pancreaticobiliary intervention. Clinical success: greater than 50% reduction in abdominal pain or level of hepatic enzyme elevations or resolution of jaundice. RESULTS From January 2008 through October 2009, 129 patients had 180 enteroscopy-ERCPs. Anatomy was Roux-en-Y: gastric bypass (n = 63), hepaticojejunostomy (n = 45), postgastrectomy (n = 6), Whipple procedure (n = 10), and other (n = 5). ERCP success was 81 of 129 (63%). Enteroscopy success: 92 of 129 (71%), of whom 81 of 92 (88%) achieved ERCP success. Reasons for ERCP failure (n = 48): afferent limb entered but pancreaticobiliary anastomosis and/or papilla not reached (n = 23), cannulation failure (n = 11), afferent limb angulation (n = 8), and jejunojejunostomy not identified (n = 6). Select interventions: anastomotic stricturoplasty (cautery ± dilation, n = 16), stone removal (n = 21), stent (n = 25), and direct cholangioscopy (n = 11). ERCP success rates were similar between Roux-en-Y gastric bypass and other long-limb surgical bypass and among SBE, DBE, and rotational overtube enteroscopy. Complications were 16 of 129, 12.4%. LIMITATIONS Retrospective study. CONCLUSION (1) ERCP is successful in nearly two-thirds of long-limb surgical bypass patients and in 88% when the papilla or pancreaticobiliary-enteric anastomosis is reached. (2) Enteroscopy success in long-limb surgical bypass is similar among SBE, DBE, and rotational overtube enteroscopy methods. (3) Referral of long-limb surgical bypass patients who require ERCP to high-volume institutions may be considered before more invasive percutaneous or surgical alternatives.


Annals of Surgery | 2009

Transvaginal natural orifice translumenal endoscopic surgery cholecystectomy: early evolution of the technique.

Andrew A. Gumbs; Dennis L. Fowler; Luca Milone; John C. Evanko; Akuezunkpa Ude; Peter D. Stevens; Marc Bessler

Introduction:Initial excitement for Natural Orifice Transluminal Endoscopic Surgery (NOTES) has been partly tempered by the reality that a NOTES procedure without laparoscopic or needleoscopic-assistance has not been performed by most groups. After safely performing laparoscopically-assisted transvaginal cholecystectomy in an IACUC-approved porcine model, we embarked on an IRB-approved protocol to ultimately perform a pure NOTES cholecystectomy. Materials and Methods:We describe our experience with performing a true NOTES tansvaginal cholecystectomy after safely accomplishing 3 laparoscopically-assisted hybrid NOTES procedures in humans. To overcome the retracting limitations of currently available endoscopes, we used a 5-mm curved or articulating retractor that was placed into the abdomen via a separate colpotomy in the second and third patient. In a fourth patient, pneumoperitoneum to 15 torr was obtained via a transvaginal trocar placed through a colpotomy made under direct vision and endoscopically placed clips were used for both the cystic duct and artery, thus, obviating the need for any transabdominally placed instruments or needles. Results:This patient was the first patient to undergo a completely NOTES cholecystectomy at our institution and to our knowledge in the United States. She was discharged on the day of surgery and has not suffered any complication after 1 month of follow-up. Conclusion:Pure NOTES transvaginal cholecystectomy without aid of laparoscopic or needleoscopic instruments is feasible and safe in humans. Additional experience with this technique will be required before comparative studies to standard laparoscopy and hybrid techniques are appropriate.


Gastrointestinal Endoscopy | 1997

Combined magnification endoscopy with chromoendoscopy in the evaluation of patients with suspected malabsorption

Lance M. Siegel; Peter D. Stevens; Charles J. Lightdale; Peter H. Green; Stephen Goodman; Reuben J. Garcia-Carrasquillo; Heidrun Rotterdam

BACKGROUND Magnification endoscopy and chromoendoscopy together have been used to evaluate mucosal detail in a number of conditions, including Barretts esophagus and flat colonic polyps, but they have not been used to evaluate villous atrophy in the proximal small intestine. METHODS Thirty-four patients suspected of having a malabsorption syndrome (either celiac disease or tropical sprue) were evaluated using an Olympus magnification gastroscope in both normal and high magnification settings. Indigo carmine dye spraying techniques were used to assist in evaluating duodenal mucosa for evidence of villous atrophy. The accuracy of endoscopically predicted villous atrophy was assessed by histologic evaluation of biopsy specimens taken in the descending duodenum. RESULTS Magnification endoscopy with dye spraying was both highly sensitive (94%) and specific (88%) in identifying patients with villous atrophy. This technique was more accurate (91%) in identifying patients with partial atrophy than standard endoscopy (9%, p < 0.01) and was also useful in identifying patients with patchy villous atrophy (5 of 5) to allow directed biopsies of abnormal tissue. CONCLUSION Magnification endoscopy with chromoendoscopy is a promising technique for the evaluation of patients with suspected malabsorption. This technique is especially valuable in patients with partial atrophy, where villous abnormalities can be patchy and the duodenum usually appears normal during standard endoscopy.


Journal of Clinical Gastroenterology | 2013

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

Michel Kahaleh; Alan Brijbassie; Amrita Sethi; Marisa Degaetani; John M. Poneros; David E. Loren; Thomas E. Kowalski; Divyesh V. Sejpal; Sandeep Patel; Laura Rosenkranz; Kevin N. Mcnamara; Isaac Raijman; Jayant P. Talreja; Monica Gaidhane; Bryan G. Sauer; Peter D. Stevens

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.


Gastrointestinal Endoscopy | 1998

Clinical implications of endoluminal ultrasonography using through-the-scope catheter probes.

Amitabh Chak; Assad Soweid; Brenda J. Hoffman; Peter D. Stevens; Robert H. Hawes; Charles J. Lightdale; Gregory S. Cooper; Marcia I. Canto; Michael Sivak

BACKGROUND Ultrasound catheter probe-assisted endosonography is a relatively new technique. The aim of this prospective multicenter study was to determine its potential clinical impact by assessing changes in diagnostic and therapeutic management affected by catheter probes compared with ultrasound endoscopes. METHODS Endosonographers at three centers selected theoretic diagnostic and therapeutic plans that would be followed if neither catheter probes nor ultrasound endoscopes were available. Patients with suitable lesions underwent endosonography with catheter probes followed by an ultrasound endoscope. Diagnostic and therapeutic plans were noted after each examination. RESULTS Sixty-six patients, of whom 15 had a stenotic esophageal cancer, 39 had a mucosal or submucosal lesion, and 12 had a stricture of the pancreaticobiliary system or the gastrointestinal tract, were enrolled. If neither form of endosonography were available, invasive or surgical diagnostic procedures would have been performed on 23 (35%) patients and surgical therapy would have been planned in 31 (47%) patients. Catheter probe-assisted ultrasonography and endoscopic ultrasonography led to a less invasive diagnostic plan in 11 (16%) and 12 (18%) patients and a less invasive therapeutic plan in 10 (15%) and 14 (21%) patients, respectively (p > 0.1 for differences). CONCLUSIONS Catheter probe-assisted endosonography has a modest effect on diagnostic and therapeutic management, comparable with endoscopic ultrasonography in the same patients. The vast majority of effected changes are toward less invasive management.


Digestive and Liver Disease | 2014

Interobserver agreement for evaluation of imaging with single operator choledochoscopy: What are we looking at?

Amrita Sethi; Jessica L. Widmer; Neeral L. Shah; Douglas K. Pleskow; Steven A. Edmundowicz; Divyesh V. Sejpal; Frank G. Gress; George H. Pop; Monica Gaidhane; Bryan G. Sauer; Peter D. Stevens; Michel Kahaleh

BACKGROUND Single operator choledochoscopy is a platform used to assist in the confirmation of diagnosis of biliary lesions. However, there are little data regarding the interobserver agreement of imaging interpretation. Our objective was to assess the interobserver agreement in single operator choledochoscopy interpretation. METHODS 38 De-identified SPY Choledochoscopy video clips were sent to 7 interventional endoscopists. They were asked to score the videos on presence of four criteria selected by the investigators: growth, stricture, hyperplasia, and ulceration. Observers also chose a final diagnosis from the categories of cancer, hyperplasia, inflammation, or normal. Kappa scores were calculated for the scoring of the four criteria and for the selection of the final diagnosis. RESULTS The overall interobserver agreement was fair in scoring for the presence of a growth (K=0.28, SE 0.035) and stricture (K=0.32, SE 0.035). Scoring for ulceration was slight to fair (K=0.17, SE 0.035). There was only slight agreement for the presence of hyperplasia (K=0.11, SE 0.035); and presumed final diagnosis based on imaging (K=0.18, SE 0.022). CONCLUSION The results of this study support the need for an effort to identify and validate cholangioscopy imaging criteria for biliary pathology. This may assist in improving the reliability of the diagnostic value of cholangioscopy as its use becomes more widespread.

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Charles J. Lightdale

Columbia University Medical Center

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Amrita Sethi

Columbia University Medical Center

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John M. Poneros

Columbia University Medical Center

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Douglas K. Pleskow

Beth Israel Deaconess Medical Center

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Tamas A. Gonda

Columbia University Medical Center

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Yang K. Chen

University of Colorado Denver

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Adam Slivka

University of Pittsburgh

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