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Dive into the research topics where John A. Dumot is active.

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Featured researches published by John A. Dumot.


Gastroenterology | 2011

Durability of Radiofrequency Ablation in Barrett's Esophagus With Dysplasia

Nicholas J. Shaheen; Bergein F. Overholt; Richard E. Sampliner; Herbert C. Wolfsen; Kenneth K. Wang; David E. Fleischer; Virender K. Sharma; Glenn M. Eisen; M. Brian Fennerty; John G. Hunter; Mary P. Bronner; John R. Goldblum; Ana E. Bennett; Hiroshi Mashimo; Richard I. Rothstein; Stuart R. Gordon; Steven A. Edmundowicz; Ryan D. Madanick; Anne F. Peery; V. Raman Muthusamy; Kenneth J. Chang; Michael B. Kimmey; Stuart J. Spechler; Ali Siddiqui; Rhonda F. Souza; Anthony Infantolino; John A. Dumot; Gary W. Falk; Joseph A. Galanko; Blair A. Jobe

BACKGROUND & AIMS Radiofrequency ablation (RFA) can eradicate dysplasia and intestinal metaplasia in patients with dysplastic Barretts esophagus (BE), and reduce rates of esophageal adenocarcinoma. We assessed long-term rates of eradication, durability of neosquamous epithelium, disease progression, and safety of RFA in patients with dysplastic BE. METHODS We performed a randomized trial of 127 subjects with dysplastic BE; after cross-over subjects were included, 119 received RFA. Subjects were followed for a mean time of 3.05 years; the study was extended to 5 years for patients with eradication of intestinal metaplasia at 2 years. Outcomes included eradication of dysplasia or intestinal metaplasia after 2 and 3 years, durability of response, disease progression, and adverse events. RESULTS After 2 years, 101 of 106 patients had complete eradication of all dysplasia (95%) and 99 of 106 had eradication of intestinal metaplasia (93%). After 2 years, among subjects with initial low-grade dysplasia, all dysplasia was eradicated in 51 of 52 (98%) and intestinal metaplasia was eradicated in 51 of 52 (98%); among subjects with initial high-grade dysplasia, all dysplasia was eradicated in 50 of 54 (93%) and intestinal metaplasia was eradicated in 48 of 54 (89%). After 3 years, dysplasia was eradicated in 55 of 56 of subjects (98%) and intestinal metaplasia was eradicated in 51 of 56 (91%). Kaplan-Meier analysis showed that dysplasia remained eradicated in >85% of patients and intestinal metaplasia in >75%, without maintenance RFA. Serious adverse events occurred in 4 of 119 subjects (3.4%); the rate of stricture was 7.6%. The rate of esophageal adenocarcinoma was 1 per 181 patient-years (0.55%/patient-years); there was no cancer-related morbidity or mortality. The annual rate of any neoplastic progression was 1 per 73 patient-years (1.37%/patient-years). CONCLUSIONS In subjects with dysplastic BE, RFA therapy has an acceptable safety profile, is durable, and is associated with a low rate of disease progression, for up to 3 years.


Gastrointestinal Endoscopy | 2009

Safety and efficacy of endoscopic spray cryotherapy for Barrett's esophagus with high-grade dysplasia.

Nicholas J. Shaheen; Bruce D. Greenwald; Anne F. Peery; John A. Dumot; Norman S. Nishioka; Herbert C. Wolfsen; J.Steven Burdick; Julian A. Abrams; Kenneth K. Wang; Damien Mallat; Mark H. Johnston; Alvin M. Zfass; Jenny O. Smith; James S. Barthel; Charles J. Lightdale

BACKGROUND Endoscopic ablation to treat Barretts esophagus (BE) with high-grade dysplasia (HGD) is associated with a decreased incidence of esophageal adenocarcinoma. Endoscopic spray cryotherapy (CRYO) demonstrates promising preliminary data. OBJECTIVE To assess the safety and efficacy of CRYO in BE with HGD. DESIGN Multicenter, retrospective cohort study. SETTING Nine academic and community centers; treatment period, 2007 to 2009. PATIENTS Subjects with HGD confirmed by 2 pathologists. Previous EMR was allowed if residual HGD remained. INTERVENTIONS CRYO with follow-up biopsies. MAIN OUTCOME MEASUREMENTS Complete eradication of HGD with persistent low-grade dysplasia, complete eradication of all dysplasia with persistent nondysplastic intestinal metaplasia, and complete eradication of all intestinal metaplasia. RESULTS Ninety-eight subjects (mean age 65.4 years, 83% male) with BE and HGD (mean length 5.3 cm) underwent 333 treatments (mean 3.4 treatments per subject). There were no esophageal perforations. Strictures developed in 3 subjects. Two subjects reported severe chest pain managed with oral narcotics. One subject was hospitalized for bright red blood per rectum. Sixty subjects had completed all planned CRYO treatments and were included in the efficacy analysis. Fifty-eight subjects (97%) had complete eradication of HGD, 52 (87%) had complete eradication of all dysplasia with persistent nondysplastic intestinal metaplasia, and 34 (57%) had complete eradication of all intestinal metaplasia. Subsquamous BE was found in 2 subjects (3%). LIMITATIONS Nonrandomized, retrospective study with no control group, short follow-up (10.5 months), lack of centralized pathology, and use of surrogate outcome for decreased cancer risk. CONCLUSIONS CRYO is a safe and well-tolerated therapy for BE and HGD. Short-term results suggest that CRYO is highly effective in eradicating HGD.


The American Journal of Gastroenterology | 2005

Deep sedation occurs frequently during elective endoscopy with meperidine and midazolam.

Sandeep Patel; John J. Vargo; Farah Khandwala; Rocio Lopez; Pat Trolli; John A. Dumot; Darwin L. Conwell; Gregory Zuccaro

BACKGROUND AND AIMS:Although moderate (conscious) sedation is intended during elective gastrointestinal endoscopy, unintended levels of deep sedation occur. The aims of this study were to prospectively evaluate the incidence and risk factors of deep sedation during elective endoscopy with meperidine and midazolam intended to maintain a level of moderate sedation.METHODS:Eighty American Society of Anesthesiology class 1-2, outpatients presenting for elective esophagogastroduodenoscopy (EGD), colonoscopy, endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasonography (EUS) were offered enrollment. Intravenous meperidine and midazolam were administered according to a standardized protocol. Hemodynamic parameters and levels of sedation were assessed and recorded by a single observer at 3-min intervals. The Modified Observers Assessment of Alertness/Sedation (MOAA/S) scale (ranging 1–5) is a subjective sedation assessment scale used to assess sedation levels. Occurrence of deep sedation, defined by MOAA/S 1–2, was recorded. Univariable and multivariable analyses were used to assess predictors of deep sedation.RESULTS:Deep sedation occurred in 54/80 (68%) patients for a total of 204/785 (26%) of total sedation assessments. The percentage of deep sedation episodes of all sedation-level observations by procedure was 26% for EGD, 11% for colonoscopy, 35% for ERCP, and 29% for EUS. Deep sedation occurred at least once in 60% of EGD, 45% of colonoscopy, 85% of ERCP, and 80% of EUS. Multivariable analysis showed that only ERCP and EUS were independent risk factors of deep sedation.CONCLUSIONS:Deep sedation occurs frequently during elective endoscopy with meperidine and midazolam used with the intent of moderate sedation. ERCP and EUS are risk factors for the occurrence of deep sedation, independent of sedation dose or length of procedure.


Gastrointestinal Endoscopy | 2009

An open-label, prospective trial of cryospray ablation for Barrett's esophagus high-grade dysplasia and early esophageal cancer in high-risk patients

John A. Dumot; John J. Vargo; Gary W. Falk; Lorraine Frey; Rocio Lopez; Thomas W. Rice

BACKGROUND Endoscopic ablation of Barretts esophagus (BE) is a treatment option for patients with high-grade dysplasia (HGD) and intramucosal carcinoma (IMCA). OBJECTIVE To assess the safety and efficacy of a unique noncontact method of liquid nitrogen cryoablation as measured by histologic response rate and cancer-free survival. DESIGN Single-center, nonrandomized cohort study. SETTING Referral center, conducted between September 2005 and September 2008. PATIENTS Patients with BE and HGD or IMCA who were deemed inoperable or who refused esophagectomy. Age, length of BE, and previous ablation were not exclusion criteria. INTERVENTION Cryoablation every 6 weeks until endoscopic resolution. EMR was used for pathologic staging of nodular areas before cryoablation and focal residual areas during the follow-up period. MAIN OUTCOME MEASUREMENTS Histologic response was defined by the worst pathology obtained at any level of the esophagus or gastric cardia in 1 of 3 categories: (1) incremental = absence of HGD and IMCA in all biopsy specimens, (2) partial = residual IMCA with absence of any dysplasia, and (3) complete = absence of any intestinal metaplasia or dysplasia. RESULTS Thirty patients underwent ablation; 9 had undergone previous ablation or mucosectomy. Twenty-seven of 30 patients (90%) had downgrading of pathology stage after treatment. Elimination of cancer or downgrading of HGD at last follow-up was 68% for HGD and 80.0% for IMCA, with a median follow-up period of 12 months (25th percentile, 6; 75th percentile, 24). Minor adverse events included mild pain (n = 7), a low incidence of mild strictures (n = 3), and lip ulcer (n = 1). One major adverse event (perforation) in a patient with Marfan syndrome occurred with the prototype system. During follow-up, 3 of 6 patients with complete response had recurrence of dysplasia or cancer in the gastric cardia. LIMITATIONS A nonrandomized, single-center study with a heterogeneous cohort of patients. CONCLUSIONS Patients with BE and HGD or IMCA have a positive response to endoscopic cryotherapy at 1-year follow-up.


Journal of Clinical Oncology | 2000

Does Paclitaxel Improve the Chemoradiotherapy of Locoregionally Advanced Esophageal Cancer? A Nonrandomized Comparison With Fluorouracil-Based Therapy

David J. Adelstein; Thomas W. Rice; Lisa Rybicki; Marjorie A. Larto; Jay P. Ciezki; Jerrold P. Saxton; Malcolm M. DeCamp; John J. Vargo; John A. Dumot; Gregory Zuccaro

PURPOSE A phase II trial of accelerated fractionation radiation with concurrent cisplatin and paclitaxel chemotherapy was performed to investigate the role of the paclitaxel, when substituted for fluorouracil (5-FU), in the chemoradiotherapy of esophageal cancer. PATIENTS AND METHODS Patients with an esophageal ultrasound stage of T(3) or N(1) or M(1) (nodal) esophageal cancer were treated with two courses of a cisplatin infusion (20 mg/m(2)/d for 4 days) and paclitaxel (175 mg/m(2) over 24 hours) concurrent with a split course of accelerated fractionation radiation (1.5 Gy bid to a total dose of 45 Gy). Surgical resection was performed 4 to 6 weeks later followed by a single identical postoperative course of chemoradiotherapy (24 Gy) in patients with significant residual tumor at surgery. Toxicity and results of this treatment were retrospectively compared with our previous 5-FU and cisplatin chemoradiotherapy experience. RESULTS Between September 1995 and July 1997, 40 patients were entered onto this study. Although dysphagia proved worse in our 5-FU-treated patients, profound leukopenia and a need for unplanned hospitalization were significantly more common in the paclitaxel group. Thirty-seven patients (93%) proved resectable for cure. The 3-year projected overall survival is 30%, locoregional control is 81%, and distant metastatic disease control is 44%. When compared with a similarly staged cohort of 5-FU-treated patients, there was no advantage for any survival function studied. CONCLUSION This paclitaxel-based treatment regimen for locoregionally advanced esophageal cancer produced increased toxicity with no improvement in results when compared with our previous 5-FU experience. Paclitaxel-based treatments must be carefully and prospectively studied before their incorporation into the standard management of esophageal cancer.


The American Journal of Gastroenterology | 2001

Optical Coherence Tomography of the Esophagus and Proximal Stomach in Health and Disease

Gregory Zuccaro; Natalia D. Gladkova; John J. Vargo; F. I. Feldchtein; Elena V. Zagaynova; Darwin L. Conwell; Gary W. Falk; John R. Goldblum; John A. Dumot; Jeffrey L. Ponsky; Grigory V. Gelikonov; B Davros; E Donchenko; Joel E. Richter

OBJECTIVE: Surveillance of Barrett’s esophagus is problematic, as high-grade dysplasia cannot be recognized endoscopically. Endoscopic ultrasound lacks the resolution to detect high-grade dysplasia. Optical coherence tomography (OCT) employs infrared light reflectance to provide in vivo tissue images at resolution far superior to endoscopic ultrasound, nearly at the level of histology. We have developed a catheter-based system well suited for study of the GI tract. The purpose of this study was to test this catheter-based OCT system and characterize the OCT appearance of normal squamous mucosa, gastric cardia, Barrett’s esophagus, and carcinoma. METHODS: The OCT catheter was passed through the operating channel of the endoscope and placed in contact with the esophageal mucosa. Image acquisition occurred in approximately 3 s. OCT images were correlated with biopsy and/or resection specimens. RESULTS: OCT was used to construct 477 images of the esophagus and stomach in 69 patients. There were unique, distinct OCT appearances of squamous mucosa, gastric cardia, Barrett’s esophagus, and carcinoma. Further, these OCT images were accurately recognized by observers unaware of their site of origin. CONCLUSIONS: OCT provides a highly detailed view of the GI wall, with clear delineation of a multiple layered structure. It is able to distinguish squamous mucosa, gastric cardia, Barrett’s esophagus, and cancer. This technique holds great potential as an adjunct to the surveillance of patients with Barrett’s esophagus, ulcerative pancolitis, and other premalignant conditions.


Gastrointestinal Endoscopy | 2009

Endoscopic spray cryotherapy for esophageal cancer: safety and efficacy

Bruce D. Greenwald; John A. Dumot; Julian A. Abrams; Charles J. Lightdale; Donald David; Norman S. Nishioka; Patrick Yachimski; Mark H. Johnston; Nicholas J. Shaheen; Alvin M. Zfass; Jenny O. Smith; Kanwar R. Gill; J.Steven Burdick; Damien Mallat; Herbert C. Wolfsen

BACKGROUND Few options exist for patients with localized esophageal cancer ineligible for conventional therapies. Endoscopic spray cryotherapy with low-pressure liquid nitrogen has demonstrated efficacy in this setting in early studies. OBJECTIVE To assess the safety and efficacy of cryotherapy in esophageal carcinoma. DESIGN Multicenter, retrospective cohort study. SETTING Ten academic and community medical centers between 2006 and 2009. PATIENTS Subjects with esophageal carcinoma in whom conventional therapy failed and those who refused or were ineligible for conventional therapy. INTERVENTIONS Cryotherapy with follow-up biopsies. Treatment was complete when tumor eradication was confirmed by biopsy or when treatment was halted because of tumor progression, patient preference, or comorbid condition. MAIN OUTCOME MEASUREMENTS Complete eradication of luminal cancer and adverse events. RESULTS Seventy-nine subjects (median age 76 years, 81% male, 94% with adenocarcinoma) were treated. Tumor stage included T1-60, T2-16, and T3/4-3. Mean tumor length was 4.0 cm (range 1-15 cm). Previous treatment including endoscopic resection, photodynamic therapy, esophagectomy, chemotherapy, and radiation therapy failed in 53 subjects (67%). Forty-nine completed treatment. Complete response of intraluminal disease was seen in 31 of 49 subjects (61.2%), including 18 of 24 (75%) with mucosal cancer. Mean (standard deviation) length of follow-up after treatment was 10.6 (8.4) months overall and 11.5 (2.8) months for T1 disease. No serious adverse events were reported. Benign stricture developed in 10 (13%), with esophageal narrowing from previous endoscopic resection, radiotherapy, or photodynamic therapy noted in 9 of 10 subjects. LIMITATIONS Retrospective study design, short follow-up. CONCLUSIONS Spray cryotherapy is safe and well tolerated for esophageal cancer. Short-term results suggest that it is effective in those who could not receive conventional treatment, especially for those with mucosal cancer.


The American Journal of Gastroenterology | 2001

A randomized, double blind study of interleukin 10 for the prevention of ERCP-induced pancreatitis

John A. Dumot; Darwin L. Conwell; Gregory Zuccaro; John J. Vargo; Steven S. Shay; Kirk A. Easley; Jeffrey L. Ponsky

OBJECTIVES: Inflammatory cytokines are released during acute pancreatitis. Interleukin 10 (IL-10) is a potent anti-inflammatory cytokine with immunosuppressive and anti-inflammatory activities. IL-10 has been shown to attenuate pancreatitis in an animal model. A double blind, placebo-controlled pilot study was conducted to evaluate the safety and efficacy of low dose IL-10 for the prevention of ERCP-induced pancreatitis. METHODS: Patients were randomized to receive a single i.v. dose of recombinant human IL-10 (8 μg/kg) or a placebo i.v. bolus injection 15 min before the procedure. Pancreatitis was defined as abdominal pain radiating to the back associated with elevated amylase or lipase two or more times the upper limit of normal requiring hospitalization for ≥2 days. Severity of pancreatitis was based on days of hospitalization. RESULTS: Two hundred patients were enrolled (101 IL-10, 99 placebo). No difference in age, gender, degree of pancreatic duct filling, therapeutic intervention, or complication was detected between the two groups. Eleven patients in the IL-10 group and nine patients in the placebo group had pancreatitis (p = 0.65). The median length of hospitalization was 4 days in the IL-10 group and 3 days in the placebo group (p = 0.75). CONCLUSIONS: IL-10 at the 8-μg/kg i.v. dose was not effective in reducing the incidence or severity of ERCP-induced pancreatitis. Further investigations are necessary to determine if manipulation of the cytokine pathway can prevent ERCP-induced pancreatitis.


Diseases of The Esophagus | 2010

Safety, tolerability, and efficacy of endoscopic low-pressure liquid nitrogen spray cryotherapy in the esophagus

Bruce D. Greenwald; John A. Dumot; J. David Horwhat; Charles J. Lightdale; Julian A. Abrams

Endoscopic cryotherapy is a new technique for ablation of esophageal dysplasia and neoplasia. Preliminary studies have shown it to be safe and effective for this indication. The objective of this study is to characterize safety, tolerability, and efficacy of low-pressure liquid nitrogen endoscopic spray cryotherapy ablation in a large cohort across multiple study sites. Parallel prospective treatment studies at four tertiary care academic medical centers in the U.S. assessed spray cryotherapy in patients with Barretts esophagus with or without dysplasia, early stage esophageal cancer, and severe squamous dysplasia who underwent cryotherapy ablation of the esophagus. All patients were contacted between 1 and 10 days after treatment to assess for side effects and complications of treatment. The main outcome measurement was the incidence of serious adverse events and side effects from treatment. Complete response for high-grade dysplasia (HGD) (CR-HGD), all dysplasia (CR-D), intestinal metaplasia (CR-IM) and cancer (CR-C) were assessed in patients completing therapy during the study period. A total of 77 patients were treated for Barretts high-grade dysplasia (58.4%), intramucosal carcinoma (16.9%), invasive carcinoma (13%), Barretts esophagus without dysplasia (9.1%), and severe squamous dysplasia (2.6%). Twenty-two patients (28.6%) reported no side effects throughout treatment. In 323 procedures, the most common complaint was chest pain (17.6%) followed by dysphagia (13.3%), odynophagia (12.1%), and sore throat (9.6%). The mean duration of any symptoms was 3.6 days. No side effects were reported in 48% of the procedures (155/323). Symptoms did not correlate with age, gender, diagnosis, or to treatment early versus late in the patients or sites experience. Logit analysis showed that symptoms were greater in those with a Barretts segment of 6 cm or longer. Gastric perforation occurred in one patient with Marfans syndrome. Esophageal stricture developed in three, all successfully treated with dilation. In 17 HGD patients, cryotherapy produced CR-HGD, CR-D, and CR-IM of 94%, 88%, and 53%, respectively. Complete regression of cancer and HGD was seen in all seven patients with intramucosal carcinoma or stage I esophageal cancer. Endoscopic spray cryotherapy ablation using low-pressure liquid nitrogen in the esophagus is safe, well-tolerated, and efficacious.


The American Journal of Gastroenterology | 1999

Immunogenicity of hepatitis A vaccine in decompensated liver disease.

John A. Dumot; David S. Barnes; Zobair M. Younossi; Steven M. Gordon; Robin K. Avery; J. Michael Henderson; William D. Carey

ObjectiveHepatitis A can cause decompensation and death in patients with previous liver injury. The hepatitis A vaccine is recommended for patients with chronic liver disease. The aim of this study was to screen, immunize, and measure the safety and antibody response of the hepatitis A vaccine in liver failure and liver transplant patients.MethodsThis was a prospective immunization trial at a referral center for liver disease and liver transplantation. A total of 193 patients with severe chronic liver disease were screened and 24 patients were vaccinated. Sixteen end stage liver disease patients were compared with eight liver transplant patients. Hepatitis A vaccinations using 1440 ELISA units were given at 0 and 2 months. Serum hepatitis A antibody titers were measured after each vaccine dose. An antibody response ≥33 mIU/ml was considered protective.ResultsScreening seropositive rate was 70 of 193 (36%) and 24 patients were available for vaccination. The median antibody titer was markedly lower in liver transplant patients, 0.0 mIU/ml compared to liver failure patients 34.7 mIU/ml (p < 0.001). Liver transplant recipients did not respond to the vaccine (0 of eight patients) compared with seven of 14 liver failure patients (seroconversion rate 50%, p= 0.02).ConclusionsLiver failure significantly reduces the antibody response to hepatitis A vaccine, and liver transplant recipients were unable to respond to the vaccine. Although this study was small, immunization should be considered early for susceptible patients with chronic liver disease because the development of liver failure may blunt the immunogenicity of the vaccine.

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