V K Sharma

Mayo Foundation for Medical Education and Research, Scottsdale, AZ, USA

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Publications (10)34.89 Total impact

  • Source
    Article: Endoscopic radiofrequency ablation for Barrett's esophagus: 5-year outcomes from a prospective multicenter trial.
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    ABSTRACT: The AIM-II Trial included patients with nondysplastic Barrett's esophagus (NDBE) treated with radiofrequency ablation (RFA). Complete eradication of NDBE (complete response-intestinal metaplasia [CR-IM]) was achieved in 98.4 % of patients at 2.5 years. We report the proportion of patients demonstrating CR-IM at 5-year follow-up. Prospective, multicenter US trial (NCT00489268). After endoscopic RFA of NDBE up to 6 cm, patients with CR-IM at 2.5 years were eligible for longer-term follow-up. At 5 years, we obtained four-quadrant biopsies from every 1 cm of the original extent of Barrett's esophagus. All specimens were reviewed by one expert gastrointestinal pathologist, followed by focal RFA and repeat biopsy if NDBE was identified. Primary outcomes were (i) proportion of patients demonstrating CR-IM at 5-year biopsy, and (ii) proportion of patients demonstrating CR-IM at 5-year biopsy or after the single-session focal RFA. Of 60 eligible patients, 50 consented to participate. Of 1473 esophageal specimens obtained at 5 years 85 % contained lamina propria or deeper tissue (per patient, mean 30 , standard deviation [SD] 13). CR-IM was demonstrated in 92 % (46 / 50) of patients, while 8 % (4 / 50) had focal NDBE; focal RFA converted all these to CR-IM. There were no buried glands, dysplasia, strictures, or serious adverse events. Kaplan-Meier CR-IM survival analysis showed probability of maintaining CR-IM for at least 4 years after first durable CR-IM was 0.91 (95 % confidence interval [CI] 0.77 - 0.97) and mean duration of CR-IM was 4.22 years (standard error [SE] 0.12). In patients with NDBE treated with RFA, CR-IM was demonstrated in the majority of patients (92 %) at 5-year follow-up, biopsy depth was adequate to detect recurrence, and all failures (4 / 4, 100 %) were converted to CR-IM with single-session focal RFA.
    Endoscopy 10/2010; 42(10):781-9. · 5.21 Impact Factor
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    Article: An economic analysis of endoscopic ablative therapy for management of nondysplastic Barrett's esophagus.
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    ABSTRACT: Advances have occurred in the development of safe and effective ablative therapies for Barrett's esophagus. The aim of the current study was to perform an economic analysis evaluating the cost-effectiveness of endoscopic ablation of nondysplastic Barrett's esophagus. A Markov model evaluated three competing strategies in a hypothetical 50-year-old cohort with nondysplastic Barrett's esophagus from a societal perspective. Strategy I -- natural history of Barrett's disease (without surveillance); Strategy II -- surveillance performed according to the American College of Gastroenterology practice guidelines; Strategy III -- endoscopic ablative therapy. The model was biased against ablative therapy with a conservative estimate of complete response and continued standard surveillance even after complete ablation. All potential complications were accounted for, and an incomplete histological response after ablation was presumed to have the same risk of progression as untreated Barrett's. Transitional probabilities, discounted cost, and utility values to estimate quality-adjusted life-years (QALY) were obtained from published information. Direct costs were used in our analysis. In baseline analysis, the ablative strategy yielded the highest QALY and was more cost-effective than endoscopic surveillance. In a Monte Carlo analysis, the relative risk of developing cancer in the strategy based on endoscopic ablation was decreased compared with the other strategies. In threshold analysis, the critical determinants of cost-effectiveness of the ablative strategy were rate of complete response to ablation, total cost of ablation, and risk of progression to dysplasia. Within the limits of the model, ablation for nondysplastic Barrett's esophagus is more cost-effective than endoscopic surveillance. Clinical trials of ablative therapy in nondysplastic Barrett's esophagus are needed to establish its effectiveness in reducing cancer risk.
    Endoscopy 06/2009; 41(5):400-8. · 5.21 Impact Factor
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    Article: Radiofrequency ablation for total Barrett's eradication: a description of the endoscopic technique, its clinical results and future prospects.
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    ABSTRACT: Stepwise circumferential and focal radiofrequency ablation using the HALO system is a novel and promising ablative modality for Barrett's esophagus. Primary circumferential ablation is performed using a balloon-based bipolar electrode, while secondary treatment of residual Barrett's epithelium is performed using an endoscope-mounted bipolar electrode on an articulated platform. It has been used as a single-modality treatment or in combination with other therapies. Recent studies suggest that this ablation technique is highly effective in removing Barrett's mucosa and its associated dysplasia without the known drawbacks of photodynamic therapy or argon plasma coagulation, such as esophageal stenosis and subsquamous foci of intestinal metaplasia (also known as "buried Barrett"). [nl]In this review paper we will explain the technical background of radiofrequency ablation using the HALO system, give a summary of its current status, and speculate on possible future applications.
    Endoscopy 01/2009; 40(12):1033-40. · 5.21 Impact Factor
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    Article: A prospective pilot trial of ablation of Barrett's esophagus with low-grade dysplasia using stepwise circumferential and focal ablation (HALO system).
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    ABSTRACT: Yearly surveillance endoscopy is carried out for Barrett's esophagus with low-grade dysplasia (LGD) so that progression to high-grade dysplasia and adenocarcinoma can be detected at the earliest stage. The aim of the study was to assess the long-term safety and effectiveness of circumferential ablation followed by focal ablation (HALO system) for eliminating Barrett's esophagus and LGD. Patients with 2 - 6 cm of Barrett's esophagus with histology demonstrating LGD on their last two sequential endoscopies over the previous 2 years and confirmed by two pathologists were enrolled in this prospective, single-center trial. Circumferential ablation was carried out at baseline and at 4 months (if residual Barrett's esophagus present). Endoscopy with 4-quadrant biopsies every 1 cm was performed at 1, 3, 6, 12, and 24 months. After 1 year, focal ablation was applied to any visible Barrett's esophagus or irregularity of the squamocolumnar junction. Patients received lansoprazole 30 mg bid. Complete responses for dysplasia (CR-dysplasia) and intestinal metaplasia (CR-IM) at 2-year follow-up, with complete response defined as "all biopsies negative for dysplasia or intestinal metaplasia" were the main outcomes. Ten patients (nine men, mean age 66.9 years, range 48 - 79) with confirmed LGD (median 4.4 cm, range 3 - 6) underwent circumferential ablation with focal ablation after 1 year as necessary. At 2 years, CR-dysplasia was 100 % and CR-IM was 90 %. There were no strictures or buried intestinal metaplasia at follow-up. A stepwise regimen of circumferential ablation followed by focal ablation appears to eradicate intestinal metaplasia (90 % CR-IM) and dysplasia (100 % CR-dysplasia) at 2-year follow-up in this trial, without stricture formation or buried intestinal metaplasia.
    Endoscopy 06/2008; 40(5):380-7. · 5.21 Impact Factor
  • Article: Patient characteristics, clinical, endoscopic, and histologic findings in adult eosinophilic esophagitis: a case series and systematic review of the medical literature.
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    ABSTRACT: The objective of our study is to describe patient characteristics, clinical, endoscopic, and pathologic features and management of adult eosinophilic esophagitis (EE). A retrospective review of adults with EE (20 or more eosinophils per high-power field) diagnosed between 1997 and 2006, and a systematic review of the medical literature was performed. Forty-two patients (31 male; 11 female) had EE. Mean (SD) age at diagnosis was 44 (15.8) years, with highest prevalence (48%) at age 20-39. Predominant symptoms were dysphagia (81%); median duration, 8 years; range, 1-30 years and food impaction (55%). Forty-three percent had allergy or atopy, 36% had asthma, 54% had peripheral eosinophilia, and 10% had a first-degree relative with dysphagia. Endoscopic findings included ringed esophagus (55%), linear furrows (33%), narrow esophagus (10%), normal esophagus (7%), and esophageal strictures (38%). Mean number of dilations was 2 (range, 1-5). There were no perforations, but superficial mucosal tears occurred in 31% of dilations. Nine patients were treated with topical fluticasone with clinical improvement in all four (100%) patients who were seen in follow-up. Pathologic findings included 20 or more eosinophils per high-power field from proximal or mid-esophageal biopsy specimens. A systematic review of 14 studies (11 manuscripts, 2 abstracts, and this case series) with 212 patients showed similar findings. EE should be suspected in young men with unexplained dysphagia or food impaction even in the absence of typical endoscopic findings of rings or corrugations, linear furrows, and narrow esophagus; diagnosis is confirmed by 20 or more eosinophils per high-power field on proximal or mid-esophageal biopsies; EE is associated with allergic or atopic disorders; topical steroids are effective in the management of EE; dilation of esophageal strictures is reasonably safe in EE.
    Diseases of the Esophagus 02/2007; 20(4):311-9. · 1.81 Impact Factor
  • Article: The yield of capsule endoscopy in patients with abdominal pain or diarrhea.
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    ABSTRACT: Capsule endoscopy, proven effective for evaluation of obscure gastrointestinal bleeding and suspected Crohn's disease, is increasingly used to investigate other small-intestine disorders, but its yield for other indications is not well known. We sought to evaluate its yield and findings for abdominal pain or diarrhea. Medical records of patients with abdominal pain or diarrhea (> 6 weeks' duration) who underwent capsule endoscopy between August 2001 and June 2004 were retrospectively reviewed for demographic data, indications, findings, diagnoses, complications, and radiologic studies. All patients had previous endoscopic or radiologic examinations (colonoscopy, enteroscopy, upper endoscopy, small-bowel series, computed tomography enterography, or computed tomography) demonstrating no abnormalities sufficient for diagnosis. 64 patients (26 men; 38 women; mean age, 43 years; age range, 19 - 83 years) who met study criteria had 68 capsule endoscopy studies. Indications were abdominal pain (35 patients), diarrhea (14), or both (15). Complete small-bowel visualization with identification of the cecum was achieved in 81 %; yield of positive findings was 9 % (6 patients). By indications, the yield was 6 % for abdominal pain, 14 % for diarrhea, and 13 % for both. Diagnoses included Crohn's disease (3), enteropathy induced by nonsteroidal anti-inflammatory drugs (2), and submucosal tumor (1). Capsule retention occurred in two patients, requiring surgical removal. Capsule endoscopy had a low yield for evaluation of abdominal pain or diarrhea and cannot be recommended as a first-line test without further study. Nonetheless, it facilitated diagnosis in 9 % of patients with negative endoscopic and radiologic examinations.
    Endoscopy 05/2006; 38(5):498-502. · 5.21 Impact Factor
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    Article: Does gastroesophageal reflux contribute to the development of chronic sinusitis? A review of the evidence.
    J K Dibaise, V K Sharma
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    ABSTRACT: Although recent studies suggest that gastroesophageal reflux disease (GERD) may contribute to a variety of ear, nose and throat and pulmonary diseases, the cause-and-effect relationship for the vast majority remains far from proven. In this article, the evidence supporting a possible causal association between GERD and chronic sinusitis has been reviewed. The evidence would suggest that: (i) a higher prevalence of GERD and a different esophagopharyngeal distribution of the gastric refluxate occurs in patients with chronic sinusitis unresponsive to conventional medical and surgical therapy compared to the general population; (ii) a biologically plausible pathogenetic mechanism exists whereby GERD may result in chronic sinusitis; and (iii) clinical manifestations of chronic sinusitis respond variably to antireflux therapy. While these findings suggest that GERD may contribute to the pathogenesis of chronic sinusitis in some patients, it is apparent that the quality of the evidence supporting each of these three lines of evidence is low and therefore does not conclusively establish a cause-and-effect relationship. A number of unresolved issues regarding prevalence, pathophysiological mechanism, diagnosis and treatment exist that deserve further investigation in order to solidify the relationship between GERD and chronic sinusitis. In conclusion, given the possible relationship between GERD and chronic sinusitis, until more convincing data are available, it may be prudent to investigate for GERD as a potential cofactor or initiating factor in patients with chronic sinusitis when no other etiology exists, or in those whose symptoms are unresponsive to conventional therapies.
    Diseases of the Esophagus 02/2006; 19(6):419-24. · 1.81 Impact Factor
  • Article: ICCE consensus for esophageal capsule endoscopy.
    V K Sharma, R Eliakim, P Sharma, D Faigel
    Endoscopy 11/2005; 37(10):1060-4. · 5.21 Impact Factor
  • Article: Current concepts and treatment options in eosinophilic esophagitis
    S. F. Pasha, V. K. Sharma, M. D. Crowell
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    ABSTRACT: Eosinophilic esophagitis (EE) is an inflammatory disorder of the esophagus that affects both children and adults, and is different from gastro-esophageal reflux disease. The immunopathogenesis of EE involves an allergic response to environmental and food allergens, and the proinflammatory cytokines IL-5 and IL-13. EE may be associated with atopic disorders and peripheral eosinophilia, and may be familial in distribution. The most common presentation is dysphagia and food impaction in adults, with additional manifestations of epigastric pain, emesis, weight loss and failure to thrive in children. Typical endoscopic findings include ringed esophagus, linear furrows, strictures and narrow esophagus. Diagnosis is confirmed by the presence of 20 or more eosinophils per high power field in the esophagus. The available treatment options include elemental diet, avoidance of specific food allergens, topical and systemic corticosteroids, and humanized monoclonal antibodies against IL-5. This review summarizes the etiopathogenesis, clinical, endoscopic and histopathological findings in EE, and describes current available treatment options.
    Curr Opin Investig Drugs. 7(11):992-6.
  • Article: Comparison of the impact of wireless versus catheter-based pH-metry on daily activities and study-related symptoms
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    ABSTRACT: AIMS: To evaluate the variation in tolerance to wireless pH-metry compared with catheter-based pH-metry, and to determine clinical characteristics that might predict reduced tolerance to wireless pH-metry. METHODS: Consecutive outpatients (n=341) completing wireless (n=234) or catheter-based pH-metry (n=106) were evaluated. All patients completed the pH-Metry Impact Scale and the pH-Metry Symptoms Scale to assess the impact of the pH-metry on activities of daily living and pH-metry associated changes in study-related symptoms. All data are presented as mean (SD) or odds ratios (95% confidence interval). RESULTS: The impact of pH-metry on activities of daily living were modest, but wireless pH-metry had less impact than catheter-based pH-metry (P=0.01). A sense of foreign body in the chest, chest discomfort, and chest pain were reported more frequently during wireless pH-metry. Difficulty swallowing and painful swallowing were more common during catheter-based pH-metry. Noncardiac chest pain was associated with increased symptom severity. Patients with poor tolerance were twice as likely to have a diagnosis of noncardiac chest pain (odds ratio=2. 53; 95% confidence interval, 1.4-4.6). CONCLUSIONS: Wireless pH-metry has less of an impact on activities of daily living but is not associated with fewer study-related symptoms compared with catheter-based pH-metry. The prevalence of specific study-related symptoms does differ between the 2 groups and noncardiac chest pain seems to be the primary risk factor for more severe study-related symptoms and reduced tolerance for wireless pH-metry. This information may be useful in helping to decide which patients should undergo the wireless pH-metry or receive additional counseling on procedural expectations.
    J Clin Gastroenterol. 45(2):100-6.