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Biomedical subjects

M F Vaezi

Publications and source records attributed to M F Vaezi.

At least 19 recordsLinked to original sources
PubMed2002

Timed barium oesophagram: better predictor of long term success after pneumatic dilation in achalasia than symptom assessment.

BACKGROUND: Symptom relief post pneumatic dilation is traditionally used to assess treatment success in achalasia patients. Recently, we showed that symptom relief and objective oesophageal emptying are concordant in about 70% of patients, while up to 30% of achalasia patients report near complete symptom relief despite poor oesophageal emptying of barium. AIMS: We now report the results of long term clinical follow up in these two groups of achalasia patients, assessing differences in symptomatic remission rates. METHODS: Achalasia patients undergoing pneumatic dilation since 1995 were evaluated both symptomatically and objectively at regular intervals. Pre and post dilation symptoms were recorded. Barium column height was measured five minutes after ingesting a fixed volume of barium per patient to assess oesophageal emptying. Patients who initially reported near complete symptom relief were divided into two groups based on objective findings on barium study: (1) complete oesophageal emptying (concordant group), and (2) poor oesophageal emptying (discordant group). Patients were followed prospectively for symptom recurrence. RESULTS: Thirty four patients with complete symptom relief post pneumatic dilation were identified. In 22/34 (65%) patients, the degree of symptom and barium height improvements was similar (concordant group). In 10/34 (30%) patients, there was < 50% improvement in barium height (discordant group). Significantly (p<0.001) more discordant (9/10; 90%) than concordant (2/22; 9%) patients failed therapy at the one year follow up. Seventeen of 22 (77%) concordant patients were still in remission while all discordant patients had failed therapy by six years of follow up. Length of time in symptom remission (mean (SEM)) post pneumatic dilation was significantly (p=0.001) less for the discordant group (18.0 (3.6) months) compared with the concordant group (59.0 (4.8) months). CONCLUSIONS: (1) Poor oesophageal emptying is present in nearly 30% of achalasia patients reporting complete symptom relief post pneumatic dilation. (2) The majority (90%) of these patients will fail within one year of treatment. (3) Timed barium oesophagram is an important tool in the objective evaluation of achalasia patients post pneumatic dilation.

Adult↗
PubMed2001

Duodenogastroesophageal reflux and methods to monitor nonacidic reflux.

The role of duodenogastroesophageal reflux (DGER), once erroneously termed "bile reflux," in causing esophageal mucosal damage has been an area of interest in both animal and human studies. However, because of the lack of appropriate techniques to accurately measure DGER, extrapolation of findings from animal studies to humans has been difficult to make. The recent advent of the Bilitec system (Metronics Instruments, Minneapolis, MN), an ambulatory bilirubin monitoring device, is increasing our knowledge of the specific role of DGER in esophageal diseases. Studies suggest that DGER without acid reflux may result in symptoms, but unless acid reflux is present simultaneously, it does not cause esophagitis. Therefore, therapies should aim at reducing both DGER and acid reflux. Studies show that this may be accomplished by antireflux surgery or the use of proton pump inhibitors, which by reducing gastric volume, decrease the damaging potential of both acid and DGER.

Animals↗
PubMed2001

Ambulatory gastric pH monitoring: proper probe placement and normal values.

BACKGROUND: Gastric acid production may persist while patients are treated with proton pump inhibitors. Twenty-four-hour intragastric pH monitoring is being used to identify gastric acid in the stomach while on medical therapy. AIM: To identify the optimal region of the stomach to demonstrate the presence of gastric acid. METHOD: Probe locations confirmed with fluoroscopy after placement and prior to removal. In experiment 1, five volunteers underwent simultaneous, 24-h gastro-oesophageal pH monitoring with the pH sensors located in the gastric antrum, body, fundus and distal oesophagus. In experiment 2, five volunteers underwent simultaneous 24-h pH monitoring with sensors located side by side in the gastric fundus assessing the reproducibility of gastric pH in this region. In experiment 3, 35 volunteers underwent 24-h pH monitoring with pH sensors located in the distal oesophagus and gastric fundus. The mean percentage time for which pH < 4 was calculated for total, upright, and supine time periods. RESULTS: pH profiles for the gastric fundus and body are similar-the mean percentage total time for which pH < 4 was 92.2% and 90.1%, respectively (P=N.S.). These values are significantly different from the antrum; pH < 4=54.6% (P < 0.01). pH values from the gastric fundus are highly reproducible (linear regression P= 0.004, r(2)=0.96). The normal values (mean +/- 95th percentile) for percentage time gastric pH < 4 in the fundus were: total 95.6 +/- 1.5%, upright 94.8 +/- 1.8%, and supine 96.5 +/- 2.3%. CONCLUSION: The fundus is the optimal location to evaluate the presence of gastric acid; pH values are highly reproducible in this area. Normal values for percentage time gastric pH < 4 for a healthy population are now defined.

Esophagus↗
PubMed2001

New techniques in measuring nonacidic esophageal reflux.

New techniques in esophageal monitoring are allowing for better differentiation in the role of different gastric refluxates in esophageal mucosal damage and patient symptoms. The Bilitec 2001 (Synectics, Stockholm, Sweden) is a portable spectrophotometer that measures bilirubin as a surrogate marker for bile reflux and multichannel intraluminal impedance (MII) (Sandhill Scientific Inc, Highlands Ranch, CO) is a new technique allowing measurement of esophageal volume refluxate. Both techniques assess the role of nonacidic esophageal reflux. Despite their novel approach in assessing nonacid reflux, both methods have limitations. Future studies in this area, however, will prove beneficial in identifying their role in diagnosis and management of patients with suspected nonacid reflux disease.

Animals↗
PubMed2001

Quantitative methods to determine efficacy of treatment in achalasia.

Determining success after achalasia therapy is an important aspect of treating this disease. Esophageal manometry, scintigraphy, and barium esophagram are the most commonly employed techniques. Recent data suggest that barium esophagram may be most practical and informative compared to manometry and scintigraphy in predicting treatment success in achalasia patients after therapy.

Barium Sulfate↗
PubMed2000

Duodenogastro-oesophageal reflux.

The role of duodenogastro-oesophageal reflux (DGOR), once erroneously termed 'bile reflux', in causing oesophageal mucosal damage has been an area of interest in both animal and human studies. However, due to the lack of appropriate techniques for accurately measuring DGOR, extrapolation of findings from animal studies to humans was difficult to make. The recent advent of the Bilitec system, an ambulatory bilirubin monitoring device, is increasing our knowledge of the specific role of DGOR in oesophageal diseases. Studies suggest that the DGOR without acid reflux may result in symptoms but unless acid reflux is present simultaneously, it does not cause oesophagitis. Therefore, our therapies should aim at reducing both DGOR and acid reflux. Studies show that this may be accomplished by anti-reflux surgery or the use of proton pump inhibitors, which, by reducing gastric volume, decrease the damaging potential of both acid and DGOR.

Anastomosis, Surgical↗
PubMed2000

Cytokeratin immunoreactivity patterns in the diagnosis of short-segment Barrett's esophagus.

BACKGROUND & AIMS: The origin of intestinal metaplasia in short segments of columnar mucosa at the esophagogastric junction has clinical importance but can be difficult to determine at endoscopy. Cytokeratin (CK) 7 and 20 patterns are specific for long-segment Barrett's esophagus; however, their utility in short-segment Barrett's esophagus has not been assessed. METHODS: Endoscopic biopsy specimens from patients with long-segment Barrett's esophagus (n = 49), suspected short-segment Barrett's esophagus (n = 43), and gastric intestinal metaplasia (n = 26) were immunostained for CK7 and CK20. Comprehensive clinical data were obtained, including age, gender, and hiatal hernia and Helicobacter pylori status. RESULTS: A Barrett's CK7/20 pattern was present in 48 (98%) of 49 patients with long-segment Barrett's esophagus, 35 (82%) of 43 with suspected short-segment Barrett's esophagus, and 0 (0%) of 26 patients with gastric intestinal metaplasia. Patients with suspected short-segment Barrett's esophagus with a Barrett's CK7/20 pattern were clinically similar to those with long-segment Barrett's esophagus. In contrast, patients with suspected short-segment Barrett's esophagus with no Barrett's CK7/20 pattern were clinically similar to those with gastric intestinal metaplasia. CONCLUSIONS: A Barrett's CK7/20 pattern identifies a subset of patients with suspected short-segment Barrett's esophagus who have a patient profile similar to that seen in long-segment Barrett's esophagus. A Barrett's CK7/20 pattern is an objective marker of Barrett's mucosa that in conjunction with appropriate clinical and endoscopic data can be used by clinicians to better define patients with short-segment Barrett's esophagus.

Aged↗
PubMed2000

CagA-positive strains of Helicobacter pylori may protect against Barrett's esophagus.

OBJECTIVE: Helicobacter pylori (H. pylori) colonization is associated with chronic gastritis, peptic ulcer disease, and adenocarcinoma of the distal stomach. However, the role of H. pylori strain variation in complicated gastroesophageal reflux disease, especially Barrett's esophagus, is unknown. Therefore, the aim of this study was to evaluate the prevalence of colonization by cagA+ and cagA- H. pylori strains in the spectrum of gastroesophageal reflux disease, including Barrett's esophagus. METHODS: A total of 251 patients undergoing endoscopy were categorized into four groups: controls, patients with gastroesophageal reflux disease alone, and patients with short- and long-segment Barrett's esophagus. All patients underwent upper endoscopies with biopsies and serum collections. H. pylori and degree of mucosal inflammation in gastric biopsies were assessed and serological assessment made for H. pylori and cagA status. RESULTS: The overall prevalence of H. pylori colonization in the study population was 35% (95% confidence interval = 29.5-41.4%) which did not differ significantly among the groups. However, colonization by cagA+ H. pylori strains was significantly more prevalent among controls (11/25; 44%) and patients with gastroesophageal reflux disease (13/36; 36%) than in patients with short-segment (2/10; 20%) or long-segment Barrett's esophagus (0/18; 0%). Patients with Barrett's esophagus were less likely to be colonized by cagA+ H. pylori strains than reflux patients without Barrett's esophagus (odds ratio = 0.27, 95% confidence interval = 0.11-0.67, p = 0.004). CONCLUSIONS: Colonization by cagA+ H. pylori strains may be protective against the formation of short- and long-segment Barrett's esophagus and its malignant complications.

Antibodies, Bacterial↗
PubMed2000

A cost-minimization analysis of alternative treatment strategies for achalasia.

OBJECTIVE: The aim of this study is to compare the costs per cure of alternative strategies for the treatment of achalasia. METHODS: A cost-minimization model compared three strategies for otherwise healthy adults of any age with achalasia: 1) laparoscopic Heller myotomy with fundoplication (LHM); 2) pneumatic dilation (PD), with LHM reserved for treatment failures; 3) botulinum toxin (Botox) injection of the lower esophageal sphincter, with PD reserved for treatment failures. Probabilities of short- and long-term efficacy, treatment failure, symptomatic recurrence rates, and complications were derived from the published literature. Only direct costs were considered during the 5-yr time horizon. RESULTS: Respective reference case costs per cure of PD, Botox, and LHM strategies were $3,111, $3,723, and $10,792. Despite short- and long-term efficacy of 96% and 94%, respectively, the LHM strategy was most costly. Initial PD remained less costly than initial Botox, provided that rates of PD efficacy and perforation were > or = 70% and < 9.5%, respectively, and cost of a Botox session was > or = $450. The results were not sensitive to the probabilities of short- and long-term response to Botox, recurrence after PD, LHM efficacy, and post-LHM gastroesophageal reflux disease, nor to the costs of LHM and PD. CONCLUSIONS: For otherwise healthy patients with achalasia, initial PD is the least costly strategy provided that the PD perforation rate remains < 10%. Initial Botox is less costly only when nonendoscopic-related costs decrease by 25%. Initial LHM is the most costly strategy under all clinically plausible scenarios. Subsequent analyses should include a longer time horizon and an assessment of patient ference for each strategy.

Adult↗
PubMed1999

Role of Helicobacter pylori cagA(+) strains and specific host immune responses on the development of premalignant and malignant lesions in the gastric cardia.

The incidence rates of gastric cardia and esophageal adenocarcinomas are increasing, but data suggest that carriage of cagA(+) Helicobacter pylori strains may protect against development of Barrett's esophagus and esophageal adenocarcinoma. Our aims were to examine the relationship between pre-malignant and malignant lesions in the gastric cardia and serum antibodies to H. pylori antigens in patients with and without complications of Barrett's esophagus. The prevalence of carditis was 40% in controls compared with 13% in patients with complicated or uncomplicated Barrett's esophagus and cardia adenocarcinoma (p < 0.001). Cardia intestinal metaplasia (IM) and atrophy were present and concordant in 28% of controls but less frequent in patients with Barrett's alone or with dysplasia/adenocarcinoma (0% for each, p < 0.001). Carriage of cagA(+) strains was present in 34% of patients with carditis and significantly associated with increased frequency and severity of cardia inflammation, IM, and atrophy but not with adenocarcinoma. IgA and HspA seropositivity were significantly increased in H. pylori-colonized patients with carditis compared to persons with normal cardia histology (p </= 0.005) but not in persons with esophageal disease or cardia adenocarcinoma. We conclude that carriage of cagA(+) H. pylori strains and induction of particular serological responses are significantly associated with marked histological findings in the gastric cardia but not with adenocarcinoma of either the gastric cardia or esophagus.

Adenocarcinoma↗
PubMed1999

Cytokeratin subsets can reliably distinguish Barrett's esophagus from intestinal metaplasia of the stomach.

The histological distinction between intestinal metaplasia involving the distal esophagus (Barrett's esophagus [BE]) and intestinal metaplasia of the stomach has important clinical implications and can be difficult even with the use of histochemical mucin stains. Cytokeratin (CK) 7 and 20 are cytoplasmic structural proteins that show restricted expression in normal and malignant epithelia of the gastrointestinal tract. The aim of this study was to determine the use of CK7 and 20 expression in the histological distinction of BE from gastric intestinal metaplasia. CK7 and 20 immunostaining was performed on randomly selected surgical resection (n = 31) and biopsy specimens (n = 34) from patients with long-segment BE and gastric resection specimens (n = 11) and gastric cardia biopsy specimens (n = 13) in patients with histological evidence of intestinal metaplasia. A unique pattern of immunoreactivity designated the Barrett's CK7/20 pattern showed superficial CK20 staining and strong CK7 staining of both superficial and deep glands in 29 of 31 (94%) esophageal resection specimens and 34 of 34 (100%) esophageal biopsy specimens form patients with long-segment BE. A Barrett's CK7/20 pattern was not observed in gastric cardia biopsy specimens (n = 13) or gastric resection specimens (n = 11) in patients with histological evidence of intestinal metaplasia. The sensitivity, specificity, and positive predictive value of a Barrett's CK7/20 pattern for a diagnosis of long-segment BE was 97%, 100%, and 100%, respectively. CK7 and 20 reactivity patterns can reliably identify the location of intestinal metaplasia in the esophagus and stomach using histological material from both routine endoscopic biopsy and surgical resection specimens.

Barrett Esophagus↗
PubMed1999

Assessment of esophageal emptying post-pneumatic dilation: use of the timed barium esophagram.

OBJECTIVES: The reported success rate of pneumatic dilation in patients with achalasia varies from 50% to 93%. This wide variability may be due to using symptom relief post-dilation as the only assessment of success. There are no studies comparing subjective symptom improvements to objective improvement in esophageal emptying after pneumatic dilation. METHODS: Patients with achalasia undergoing pneumatic dilation from 1995 to 1997 were evaluated. Pre- and post-dilation symptoms were recorded using a standardized scoring system. Barium column height was measured 1 min and 5 min after upright ingestion to assess esophageal emptying. Based on percentage of total symptom and barium height improvement post-dilation, patients were grouped according to one of nine outcomes; the association between subjective and objective parameters of improvement was tested. RESULTS: A total of 37 patients underwent 53 pneumatic dilations. There was a significant association (p < 0.001) between improvement in patient symptoms and barium height. In 38 of 53 (72%) pneumatic dilations, the degree of symptom and barium height improvement was similar. Near complete symptom resolution was reported after 26 dilations. In eight of 26 (31%) patients however, there was < 50% improvement in barium height (group A). Compared with the 16 patients with 91-100% improvement in both symptoms and barium height (group B), forward stepwise regression identified age as the only difference between the two groups, with group A patients being significantly (p = 0.04) older. CONCLUSIONS: Objective assessment of esophageal emptying pre- and post-dilation identifies an important subset of patients with poor esophageal emptying who report near complete symptom resolution. This group may benefit from any early repeat pneumatic dilation.

Adult↗
PubMed1999

Botulinum toxin versus pneumatic dilatation in the treatment of achalasia: a randomised trial.

BACKGROUND: Intrasphincteric injection of botulinum toxin is a new treatment option for achalasia. AIMS: To compare the immediate and long term efficacy of botulinum toxin with that of pneumatic dilatation. METHODS: Symptomatic patients with achalasia were randomised to botulinum toxin (22 patients, median age 57 years) or pneumatic dilatation (20 patients, median age 56 years). Symptom scores were assessed initially, and at one, three, six, nine, and 12 months after treatment. Objective assessment included oesophageal manometry initially and at one month, and barium oesophagram initially and at one, six, and 12 months post-treatment. RESULTS: Pneumatic dilatation resulted in a significantly (p=0.02) higher cumulative remission rate. At 12 months, 14/20 (70%) pneumatic dilatation and 7/22 (32%) botulinum toxin treated patients were in symptomatic remission (p=0.017). Failure rates were similar initially, but failure over time was significantly (p=0.01) higher after botulinum toxin (50%) than pneumatic dilatation (7%). Pneumatic dilatation resulted in significant (p<0.001) reduction in symptom scores, and lower oesophageal sphincter pressure, oesophageal barium column height, and oesophageal diameter. Botulinum toxin produced significant reduction in symptom scores (p<0.001), but no reduction in objective parameters. CONCLUSIONS: At one year pneumatic dilatation is more effective than botulinum toxin. Symptom improvement parallels objective oesophageal measurements after pneumatic dilatation but not after botulinum toxin treatment for achalasia.

Adult↗
PubMed1999

Achalasia: diagnosis and management.

Achalasia is a primary esophageal motor disorder of unknown cause that produces complaints of dysphagia, regurgitation, and chest pain. The current treatments for achalasia involve the reduction of lower esophageal sphincter (LES) pressure, resulting in improved esophageal emptying. Calcium channel blockers and nitrates, once used as an initial treatment strategy for early achalasia, are now used only in patients who are not candidates for pneumatic dilation or surgery, and in patients who do not respond to botulinum toxin injections. Because of the more rigid balloons, the current pneumatic dilators are more effective than the older, more compliant balloons. The graded approach to pneumatic dilation, using the Rigiflex (Boston Scientific Corp, Boston, MA) balloons (3.0, 3.5, and 4.0 cm) is now the most commonly used nonsurgical means of treating patients with achalasia, resulting in symptom improvement in up to 90% of patients. Surgical myotomy, once plagued by high morbidity and long hospital stay, can now be performed laparoscopically, with similar efficacy to the open surgical approach (94% versus 84%, respectively), reduced morbidity, and reduced hospitalization time. Because of the advances in both balloon dilation and laparoscopic myotomy, most patients with achalasia can now choose between these two equally efficacious treatment options. Botulinum toxin injection of the LES should be reserved for patients who can not undergo balloon dilation and are not surgical candidates.

Adult↗
PubMed1998

Current therapies for achalasia: comparison and efficacy.

Achalasia is a primary esophageal motor disorder of unknown etiology producing complaints of dysphagia, regurgitation, and chest pain. The current treatments for achalasia involve the reduction of lower esophageal sphincter (LES) pressure resulting in improved esophageal emptying. Calcium channel blockers and nitrates, once used as initial treatment strategy for early achalasia, are now only used in patients who are not candidates for pneumatic dilation or surgery and those not responding to botulinum toxin injections. By virtue of the more rigid balloons, the current pneumatic dilators are more effective and have better efficacy than the older more compliant balloons. The graded approach to pneumatic dilation using the Rigiflex balloons (3.0, 3.5, and 4.0 cm) are now the most commonly used nonsurgical means of treating patients with achalasia, resulting in symptom improvement in up to 90% of patients. Surgical myotomy, once with high morbidity and long hospital stay, can now be performed laparoscopically with similar efficacy to the open surgical approach (94% vs. 84%, respectively), reduced morbidity, and hospitalization time. Given the advances in both balloon dilation and laparoscopic myotomy, most patients with achalasia can now choose between these two equally efficacious treatment options. Botulinum toxin injection of the LES should be reserved for patients who cannot undergo balloon dilation and are not surgical candidates.

Algorithms↗
PubMed1998

Helicobacter pylori and gastroesophageal reflux disease: the bug may not be all bad.

Peptic ulcer disease and gastric cancer of the antrum and body have been declining in the 20th century. In contrast, a new group of diseases are increasingly rapidly in Western countries: gastroesophageal reflux disease, Barrett's esophagus, and adenocarcinoma of the distal esophagus. Recent studies suggest this phenomenon may be related to the simultaneous fall in the prevalence of Helicobacter pylori (H. pylori) colonization, especially by the virulent cagA + strains. H. pylori infection with the cagA+ strain is potentially protective against the spectrum of gastroesophageal reflux disease because it lowers intragastric acidity as the result of a pangastritis, frequently with multifocal gastric atrophy and possibly increased intragastric ammonia production. Assuming that some types of H. pylori strains are protective, our entire approach to the worldwide elimination of this organism, sometimes indiscriminately, will need critical reevaluation.

Adenocarcinoma↗