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Prateek Sharma

Publications and source records attributed to Prateek Sharma.

At least 19 recordsLinked to original sources
PubMed2006

The development and validation of an endoscopic grading system for Barrett's esophagus: the Prague C & M criteria.

BACKGROUND & AIMS: Barrett's esophagus (BE) is a premalignant condition for esophageal adenocarcinoma, its diagnosis relying initially on recognition of a columnar-lined distal esophagus. We aimed to develop and validate explicit, consensus-driven criteria for the endoscopic diagnosis and grading of BE. METHODS: An international working group agreed on criteria and developed materials for their formal evaluation using video-endoscopic recordings gathered in a standardized manner in 29 patients. The criteria included assessment of the circumferential (C) and maximum (M) extent of the endoscopically visualized BE segment as well as endoscopic landmarks. The recordings were scored according to these criteria by a separate international panel of 29 endoscopists. RESULTS: The Prague C & M Criteria give explicit guidance on the endoscopic recognition of BE and grading of its extent. The overall reliability coefficients (RC) for the assessment of the C & M extent of the endoscopic BE segment above the gastroesophageal junction were 0.95 and 0.94, respectively. The rates of exact agreement (for C & M values) for pairwise comparisons of individual patient values were 53% and 38%, respectively, whereas the values for agreement within a 2-cm interval were 97% and 95%, respectively. The overall RC for endoscopic recognition of BE >/=1 cm was 0.72, whereas for BE <1 cm, it was 0.22. The RCs for recognizing the location of the gastroesophageal junction and the diaphragmatic hiatus were 0.88 and 0.85, respectively. CONCLUSIONS: The Prague C & M Criteria have high overall validity for the endoscopic assessment of visualized BE lengths.

Barrett Esophagus↗
PubMed2006

Gastric and esophageal pH in patients with Barrett's esophagus treated with three esomeprazole dosages: a randomized, double-blind, crossover trial.

BACKGROUND: It has been suggested that patients with Barrett's esophagus (BE) are unusually resistant to the antisecretory effects of proton pump inhibitors (PPIs). OBJECTIVES: To compare intragastric and intraesophageal acidity in patients with BE receiving esomeprazole 40 mg three times daily (t.i.d.), esomeprazole 40 mg twice daily (b.i.d.), and esomeprazole 20 mg t.i.d. METHODS: In this randomized, double-blind, three-way crossover study, patients with long-segment BE received each of the three esomeprazole dosages for 5 days separated by 10-14-day washout periods. Intragastric and intraesophageal pHs were measured for 24 h on day 5. RESULTS: Among 31 patients with evaluable pH data, intragastric pH was >4.0 for 88.4%, 81.4%, and 80.4% of day 5 after treatment with esomeprazole 40 mg t.i.d., 40 mg b.i.d., and 20 mg t.i.d., respectively. Esomeprazole 40 mg t.i.d. was significantly more effective than the other dosages (p < 0.01). Intraesophageal pH was <4.0 for mean values of <5% of the monitoring period with all the three dosing regimens, but esophageal pH remained <4.0 for >5% of the time in 16%, 23%, and 19% of patients receiving esomeprazole 40 mg t.i.d., 40 mg b.i.d., and 20 mg t.i.d., respectively. All dosages were well tolerated. CONCLUSIONS: All the three esomeprazole dosages significantly decreased intragastric acidity and reduced esophageal acid exposure to mean normal values in the total group of patients with BE. However, abnormal esophageal acid exposure continued in 16-23% of patients despite the significant decrease in gastric acidity. These results suggest that the apparent "PPI resistance" described in patients with BE may be caused by their profound reflux diathesis rather than by gastric resistance to the antisecretory effects of PPIs.

Aged↗
PubMed2006

Water quality modelling of the river Yamuna (India) using QUAL2E-UNCAS.

This paper describes the utility of QUAL2E as a modelling package in the evaluation of a water quality improvement programme. In this study, QUAL2E was applied to determine the pollution loads in the river Yamuna during its course through the national capital territory of Delhi, India. The study aimed at examining the influence of different scenarios on river water quality. Four different pollution scenarios were analysed besides the 'business as usual' situation. The study revealed that it was necessary to treat the discharge from drains to the river Yamuna and diversion of a substantial load to the Agra canal for further treatment was also essential. It was also established through this study that maintaining a flow rate of more than 10 m(3)/s in the river could also help preserve the river's water quality. To clearly display the model outcomes and demarcate polluted zones in the river stretch, model results were interfaced with a Geographical Information System (GIS) to produce cartographic outputs. In addition, uncertainty analysis in the form of first-order error analysis and Monte Carlo analysis was performed, to realise the effect of each model parameter on DO and BOD predictions. The uncertainty analysis gave satisfactory results on simulated data.

Environmental Monitoring↗
PubMed2006

Dysplasia and cancer in a large multicenter cohort of patients with Barrett's esophagus.

BACKGROUND & AIMS: The exact incidence of adenocarcinoma in patients with Barrett's esophagus (BE) is not known and is reported to vary from 0.2%-2% per year. Published series of patients with BE have included relatively small numbers of patients with limited duration of follow-up. The goal of this study was to define the prevalence and incidence of dysplasia and cancer and evaluate the paths of progression in a large multicenter cohort of BE patients. METHODS: The BE study is a multicenter clinical and endoscopic outcomes project involving a single large database of patients with BE. Data from each of the participating centers were merged into the main study database. Cancers and HGD occurring within 12 months of the index endoscopy were regarded as prevalent cases. RESULTS: One thousand three hundred seventy-six patients met the study criteria (95% white, 14% women); 91 patients had cancer at the initial endoscopy (prevalent cases, 6.7%; 95% confidence interval [CI], 4.8%-8.7%). Six hundred eighteen patients were followed for a total of 2546 patient-years; mean follow-up was 4.12 years. Twelve patients developed cancer during follow-up, a cancer incidence of 1 in 212 patient-years of follow-up (0.5% per year; 95% CI, 0%-1.1%). The combined incidence of HGD and/or cancer was 1 in 75 patient-years of follow-up or 1.3% per year (95% CI, 0%-2.2%). Of the 34 patients developing HGD and/or cancer, 18 patients (53%) had at least 2 initial consecutive endoscopies with biopsies revealing nondysplastic mucosa. The incidence of LGD was 4.3% per year (95% CI, 2.8%-6.0%). In the 156 patients with LGD, regression to no dysplasia occurred in 66%, persistent LGD in 21%, and progression to HGD/cancer in 13%. The incidence of cancer in patients with LGD was 1 in 156 patient-years of follow-up or 0.6% per year (95% CI, 0%-1.3%). CONCLUSIONS: Preliminary results from this trial define the prevalence and incidence of dysplasia and cancer in a multicenter cohort of patients with BE. At least half the patients who developed HGD and/or cancer had 2 consecutive initial endoscopies with biopsies revealing nondysplastic mucosa. The majority of patients with LGD regressed and had a cancer incidence similar to all BE patients.

Adenocarcinoma↗
PubMed2006

The rationale for screening and surveillance of Barrett's metaplasia.

Oesophageal adenocarcinoma is a rare cancer; however, it is the most rapidly increasing cancer in the western world. Barrett's oesophagus is the only recognised precursor and is associated with the majority of cases of adenocarcinoma. The role of screening and surveillance in patients with Barrett's oesophagus remains controversial. There is insufficient evidence to show that screening improves survival and is cost-effective. Indirect evidence suggests that patients diagnosed with cancer while undergoing surveillance endoscopy are diagnosed at an earlier stage and have an improved survival. The problems with current surveillance techniques include lack of data on natural history of Barrett's oesophagus, test invasiveness, costs, lack of standardisation and validation of biopsy and treatment protocols, and endoscopy intervals. The use of novel endoscopic techniques and biomarkers combined with better identification of high-risk groups could make screening and surveillance a cost-effective practice in the future.

Adenocarcinoma↗
PubMed2006

The utility of a novel narrow band imaging endoscopy system in patients with Barrett's esophagus.

BACKGROUND: A narrow band imaging (NBI) endoscopy system has been developed that allows superficial surface imaging of esophageal tissue in vivo. OBJECTIVE: The objective was to assess the potential of NBI for prediction of histology during screening and surveillance endoscopy in patients with Barrett's esophagus (BE). DESIGN: A prospective cohort study. SETTING: Veterans Affairs Medical Center. PATIENTS: Fifty-one patients with known or suspected BE. METHODS: NBI images were graded according to mucosal pattern (ridge/villous, circular and irregular/distorted) and vascular pattern (normal and abnormal), and correlated with histology in a prospective, blinded manner. MAIN OUTCOME MEASUREMENTS: Biopsy-confirmed intestinal metaplasia (IM) and dysplasia were used as the outcome measures. RESULTS: Of 51 patients (mean BE length 3.5 cm), 28 had IM without dysplasia, 8 had low-grade dysplasia (LGD), 7 had high-grade dysplasia (HGD), and 8 had cardiac-type mucosa. The sensitivity, specificity, and positive predictive value of ridge/villous pattern for diagnosis of IM without HGD were 93.5%, 86.7%, and 94.7%, respectively. The sensitivity, specificity, and positive predictive value of irregular/distorted pattern for HGD were 100%, 98.7%, and 95.3%, respectively. If biopsies were limited to areas with irregular/distorted pattern, no patient with HGD would have been missed. However, NBI was unable to distinguish areas of IM from those with LGD. LIMITATIONS: The open study design without a control group was the main limitation. CONCLUSIONS: NBI is a novel diagnostic tool with a high degree of accuracy for the detection of metaplastic and dysplastic tissue within the BE segment.

Adult↗
PubMed2006

An evidence-based, Latin-American consensus on gastro-oesophageal reflux disease.

In recognition of the high prevalence of gastro-oesophageal reflux disease (GORD) and its importance in Latin America, the InterAmerican Association of Gastroenterology and the InterAmerican Society of Digestive Endoscopy organized a Latin-American Consensus on GORD in Cancun, Mexico in September 2004. The main objectives of the consensus meeting were to provide evidence-based guidance with respect to the diagnosis and treatment of GORD, relevant to all countries in the region. The methodology, results and recommendations of the consensus are described in detail.

Adult↗
PubMed2006

Barrett's esophagus.

PURPOSE OF REVIEW: Barrett's esophagus continues to be a popular topic among clinicians and researchers alike. Population based studies have finally been undertaken to better identify subset populations at high risk of developing Barrett's esophagus, and possible better tolerated alternatives to standard endoscopy for cost-effective screening. In addition, several studies over the past year have marked a transition from identifying those with Barrett's esophagus and in need of intensive surveillance, to an increasing number of novel treatment therapies that are now primed to move from experimental protocols to clinical practice. RECENT FINDINGS: Obesity's role as a risk factor for the development of Barrett's esophagus continues to be better defined. Various disorders affecting the motility of the gastrointestinal tract, such as celiac sprue and scleroderma, and their relationship with Barrett's esophagus development are becoming more widely recognized. The use of endoscopic mucosal resection and photodynamic therapy for treatment of dysplastic Barrett's esophagus continues to gain increased acceptance, with an additional wealth of supportive data for its effectiveness becoming available. SUMMARY: The past year has brought many advances in the epidemiology and endoscopic treatment of those with Barrett's esophagus. Clinicians will benefit from this review of these advances to ensure better patient outcomes.

Barrett Esophagus↗
PubMed2006

Detection of Barrett's esophagus after endoscopic healing of erosive esophagitis.

BACKGROUND: The presence of erosive esophagitis (EE) in patients presenting for upper endoscopy may prevent the detection of underlying Barrett's esophagus (BE) in the distal esophagus. AIM: To prospectively determine the proportion of patients detected with BE upon repeat endoscopy after healing of EE. METHODS: Patients with endoscopically confirmed EE without BE were treated with standard doses of acid suppression therapy and a repeat endoscopy was performed to assess the presence of BE. If columnar mucosa was visualized in the distal esophagus, targeted biopsies were obtained and all biopsies were evaluated for the presence of intestinal metaplasia. BE was defined as columnar mucosa in the distal esophagus with intestinal metaplasia on biopsy. RESULTS: A total of 172 patients with reflux symptoms were diagnosed with EE without BE on initial endoscopy. They were treated with standard doses of proton pump inhibitor therapy, and after a mean duration of 11 wk (range 8-16 wk), a repeat endoscopy was performed to confirm healing of EE and to document the presence of BE. On repeat endoscopy, EE was completely healed in 116 patients (67%), and of those, BE was suspected in 32 patients (i.e., columnar-lined distal esophagus) and was confirmed in 16 patients (13.8%). In the 56 patients with persistent EE on repeat endoscopy, columnar mucosa in areas of previously healed esophagitis was visualized in 8 and confirmed in 5 patients (8.9% of nonhealed cases). Overall, 21 (12%) patients were confirmed with BE on repeat endoscopy; all men, mean age 61 yr with a median BE length of 0.5 cm (range 0.5-5 cm, interquartile range 0.5 cm). The majority of these patients (N = 19) had short segment Barrett's esophagus (SSBE) (i.e., length <3 cm). CONCLUSIONS: In patients with EE undergoing treatment with acid suppressive therapy, BE (mainly SSBE) is detected in approximately 12% of patients on repeat endoscopy. Patients with reflux symptoms undergoing endoscopy for the detection of BE (i.e., screening) should be treated with acid suppressive therapy prior to endoscopy to enhance the yield of BE. Alternatively, if the goal is to document BE and if EE is found at the initial endoscopy, then repeat endoscopy may be considered after acid suppressive therapy.

Barrett Esophagus↗
PubMed2006

Advances in esophageal imaging: practical applications for clinicians.

In the 1960s, the revolution in the diagnosis and management of gastrointestinal diseases began with the introduction of the first flexible fiber endoscope. Since then, the technologies have evolved greatly. Particularly in recent years, much emphasis has been placed on developing new gastrointestinal endoscopy technologies or techniques in order to provide a precise and even a "real time" endoscopic diagnosis. Magnification and high-resolution endoscopy, chromoendoscopy, and narrow band imaging stand at the forefront of the novel endoscopic techniques for the diagnosis of conditions such as squamous cell carcinoma, Barrett's esophagus, and gastroesophageal reflux disease. This review summarizes the recent advances in esophageal imaging and its practical applications for clinicians.

Adenocarcinoma↗
PubMed2005

The frequency of Barrett's esophagus in high-risk patients with chronic GERD.

BACKGROUND: The reported frequency of Barrett's esophagus (BE) in patients with reflux symptoms varies from 5% to 15%. The exact frequency of long-segment BE (LSBE) (>3 cm) and short-segment BE (SSBE) (<3 cm) in patients with chronic symptoms of GERD is uncertain. The aim of this study was to determine the frequency of LSBE and SSBE in consecutive patients presenting for a first endoscopic evaluation with GERD as the indication. METHODS: Consecutive patients presenting to the endoscopy unit of a Veterans Affairs Medical Center for a first upper endoscopy with the indication of GERD were prospectively evaluated. Demographic information (gender, race, age), data on tobacco use and family history of esophageal disease, and body mass index (BMI) were recorded for all patients. Before endoscopy, all patients completed a validated GERD questionnaire. The diagnosis of BE was based on the presence of columnar-appearing mucosa in the distal esophagus, with confirmation by demonstration of intestinal metaplasia in biopsy specimens. All patients with erosive esophagitis on the initial endoscopy underwent a second endoscopy to document healing and to rule-out underlying BE. Patients with a history of BE, alarm symptoms (dysphagia, weight loss, anemia, evidence of GI bleeding), or prior endoscopy were excluded. RESULTS: A total of 378 consecutive patients with GERD (94% men, 86% white; median age 56 years, range 27-93 years) were evaluated. A diagnosis of BE was made in 50 patients (13.2%). The median length of Barrett's esophagus (BE) was 1.0 cm (range 0.5-15.0 cm). Of the patients with BE, 64% had short-segment BE (SSBE) (overall SSBE frequency 8.5%). The overall frequency of long-segment BE (LSBE) was 4.8%. A hiatal hernia was detected in 62% of the patients with BE. Of the 50 patients with BE (median age 62 years, range 29-81 years), 47 (94%) were men and 98% were white. Eighteen patients (36%) were using tobacco at the time of endoscopy; 23 (46%) were former users. The median body mass index (BMI) of patients with BE was 27.3 (overweight). There were no significant differences between patients with LSBE and SSBE with respect to age, gender, ethnicity, BMI, and GERD symptom duration. CONCLUSIONS: The frequency of BE in a high-risk patient group (chronic GERD, majority white men, age > 50 years) who sought medical attention is 13.2%, with the majority (64%) having SSBE. These data suggest that the frequency of BE in patients with GERD has not changed. The true prevalence of BE in the general population, including those who do not seek care, is undoubtedly lower, currently and historically. The majority of patients with BE are overweight and have a hiatal hernia. Demographic data for patients with LSBE and SSBE are similar, indicating that these are a continuum of the same process.

Adult↗
PubMed2005

Visible endoscopic and histologic changes in the cardia, before and after complete Barrett's esophagus ablation.

BACKGROUND: Adverse events associated with the thermal ablation of Barrett's esophagus (BE) include the generation of gastric mucosa buried beneath the neosquamous regrowth, and unrecognized development and growth of adenocarcinomas. No reports exist regarding the endoscopic appearance and histology of the cardia before and after BE ablation. The aim of our study was to assess the relative frequency of the occurrence of visible endoscopic and histologic changes in the cardia, before and after complete BE ablation. METHODS: A subset analysis of patients with uncomplicated BE, BE with dysplasia, or early carcinoma, who had been enrolled into one of 4 ongoing prospective studies of mucosal ablation, was examined. Eighty-two patients were identified who entered a BE ablation study, with 75 of these completing BE mucosal ablation. Cardia biopsy specimens were taken in all patients before ablation and serially after BE ablation. Cardia histology was graded by using the modified Sydney System for gastritis. RESULTS: Before ablation, cardia nodules were noted in 3, cardia intestinal metaplasia (IM) in 7 (8.5%), and none harbored cardia dysplasia. Postablation surveillance ranged from 3 to 75 months (mean 31.1 months [19.5]). Six subjects (8%) developed cardia nodules during surveillance; cardia IM was found in 21(28%), with 17 of these being a new finding (incidence of 25%). Cardia low-grade dysplasia incidence was 1.3% and high-grade dysplasia was 4% after BE ablation. CONCLUSIONS: The pathophysiology of the abnormal cardia histology and the endoscopic lesions (nodules) is unclear, but endoscopic surveillance of not only the neosquamous epithelium but also the cardia should be considered after ablation, especially in those high-grade dysplasia and early adenocarcinoma BE patients.

Adenocarcinoma↗
PubMed2005

Narrow band imaging in Barrett's esophagus.

Barrett's esophagus is the premalignant lesion for esophageal and esophagogastric junction adenocarcinoma. Progression of Barrett's esophagus to dysplasia and cancer can occur, thus requiring endoscopy with random biopsy examinations. Currently, the diagnosis of metaplastic and dysplastic mucosa within the esophagus requires endoscopy with biopsy examination of abnormal-appearing tissue. The presence of intestinal metaplasia and dysplasia within the esophagus often is patchy, and our current practices of performing standard endoscopy with random biopsy examinations are inaccurate. Narrow band imaging is among several tools used in the esophagus to improve detection of Barrett's esophagus and associated dysplasia. Current studies show that these techniques are promising, although the results still are preliminary.

Barrett Esophagus↗