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Biomedical subjects

N Vakil

Publications and source records attributed to N Vakil.

At least 73 records · Page 4Linked to original sources
PubMed1998

Palliation of malignant esophageal obstruction due to intrinsic and extrinsic lesions with expandable metal stents.

OBJECTIVE: Metal stents have become the standard of care for esophageal stenting. The aim of this study was to determine the safety and efficacy of metal stents for the palliation of dysphagia caused by extraesophageal malignancies compressing the esophagus, compared with that caused by intrinsic lesions involving the esophagus. METHODS: Expandable metal stents were placed in 46 consecutive patients with dysphagia caused by malignant extrinsic compression of the esophagus (n=24) and intrinsic esophageal strictures (n=22). Quality of life was determined by a dysphagia score and the Karnofsky performance scale. Patients were followed until death. RESULTS: Stents were successfully deployed in all 24 patients. Dysphagia scores improved from a median of 3 (range, 3-4; mean, 3.5+/-0.2) to a median of 2 (range, 1-4; mean, 1.6+/-0.4; p < 0.0001) in the extrinsic group, and from a median of 3 (range, 2-4) to a median of 1 (range, 1-3) in the intrinsic group (p < 0.0001). The improvement was significantly greater (p=0.01) in the intrinsic group. There was no significant difference in the Karnofsky score between the two groups. CONCLUSIONS: Patients with intrinsic lesions have better palliation of dysphagia than those with extrinsic lesions. Future studies with other study designs will need to consider this.

Aged↗
PubMed1998

Cost-effectiveness of noninvasive testing and treatment strategies for H. pylori infection in children with dyspepsia.

OBJECTIVE: We sought to model the cost-effectiveness of endoscopy, noninvasive testing and treatment strategies for Helicobacter pylori infection in children with recurrent abdominal pain in two health care systems, those of the United States and Finland. METHODS: Initial serological testing and treatment was compared to empirical treatment with antimicrobials, endoscopy with rapid urease testing, and 13C urea breath testing. Key assumptions and ranges were obtained from the published literature. Costs were determined for the acquisition of various tests and actual reimbursement figures were used for procedural costs. RESULTS: The disease management costs were very similar for both endoscopy ($643.00) and serology ($646.00) in the United States. In Finland, endoscopy ($173.00) was less expensive than serology ($192.00). The 13C urea breath test was the most expensive procedure in the United States. Sensitivity analysis demonstrated that serological testing became the preferred path if its cost was < $42 in the United States. Empirical treatment of children with dyspepsia was not cost-effective in either country. Sensitivity analysis showed that when prevalence of infection was > 53% in children with recurrent abdominal pain, empirical therapy with endoscopy reserved for failures was the optimal path. CONCLUSIONS: In developed countries like the United States and Finland, significant cost savings are unlikely with an initial test and treat strategy based on serology. Noninvasive testing and treatment of H. pylori infection can be cost-effective in populations with highly prevalent rates of infection.

Anti-Bacterial Agents↗
PubMed1998

Metal stents for the palliation of inoperable upper gastrointestinal stenoses.

We sought to determine the efficacy of metal stents in the palliation of malignant upper gastrointestinal stenoses. Six patients with inoperable malignant obstruction of the upper gastrointestinal tract, intractable nausea and vomiting, and an inability to maintain an oral intake were studied. A metal stent was inserted under endoscopic control and deployed in the stenosis. Stents were successfully deployed in all patients, and there were no immediate complications. All patients were able to eat after the procedure and parenteral nutrition was discontinued in all. Mean survival was 23 +/- 8.6 days. We conclude that metal stents represent a promising approach to the management of selected patients with malignant upper gastrointestinal stenoses and that their use warrants further study.

Adult↗
PubMed1998

A prospective, controlled study of Helicobacter pylori seroprevalence in coronary artery disease.

OBJECTIVE: Recent studies have suggested that chronic infections may be a risk factor for coronary artery disease. The aim of this study was to determine whether Helicobacter pylori (H. pylori) infection was an independent risk factor for coronary artery disease. METHODS: A total of 179 patients undergoing coronary angiography for suspected coronary artery disease were prospectively studied. Angiograms were read by experienced invasive cardiologists blinded to the results of H. pylori serology, which was determined by a validated multiwell ELISA assay. RESULTS: A total of 121 patients (68%) had evidence of coronary artery disease, whereas 58 patients (32%) had normal coronary angiograms. Of the 121 patients with coronary artery disease, 29 had single vessel disease, 39 had double vessel disease, and 53 had triple vessel disease, respectively. There was no significant difference in seroprevalence of H. pylori infection in patients with and without coronary artery disease (p = 0.63). The odds ratio (after adjustment for other known risk factors) for coronary artery disease in H. pylori-infected subjects was 0.45 (95% CI = 0.15, 1.37; p = 0.107). In patients with coronary artery disease, H. pylori infection did not increase the likelihood of severe disease (odds ratio for triple vessel disease = 0.53; 95% CI 0.18, 1.60; p = 0.201). CONCLUSION: H. pylori infection rates are similar in patients with normal and abnormal coronary arteries, and infection with H. pylori is not an independent risk factor for coronary artery disease. In patients who have coronary artery disease, H. pylori infection is not a risk factor for more severe disease. These data argue against a causal role for H. pylori in the pathogenesis of coronary artery disease.

Adult↗
PubMed1998

Clarithromycin-resistant Helicobacter pylori in patients with duodenal ulcer in the United States.

BACKGROUND: Clarithromycin is a key component of several antimicrobial treatment regimens for Helicobacter pylori. Cure rates with clarithromycin-containing regimens are significantly decreased when resistance is present. Resistance develops by a point mutation in the ribosomal RNA of some organisms exposed to clarithromycin. We studied the prevalence of clarithromycin-resistant organisms in patients with duodenal ulcer in the United States from 1993-96. METHODS: Patients with endoscopic evidence of a duodenal ulcer were studied. Gastric biopsies were cultured for H. pylori and antimicrobial sensitivity was determined by the E-test (epsilometer agar diffusion gradient). RESULTS: In 1993-94, three of 78 patients (4%) had clarithromycin-resistant strains of H. pylori. In 1995-96, 44 of 348 patients (12.6%; p = 0.025) had resistant strains of H. pylori. Patients who had previously failed antimicrobial treatment for H. pylori accounted for much of the increase in resistant strains (25%). CONCLUSIONS: Failed therapy with clarithromycin-based regimens is a growing cause of antimicrobial resistance in H. pylori in the United States. Whereas the overall rates of primary resistance are low, the increase in secondary resistance over a short period of time is worrisome. New treatments that prevent the emergence of resistance may be important in the future.

Anti-Bacterial Agents↗
PubMed1997

Evolving therapy for Helicobacter pylori infection: efficacy and economic impact in the treatment of patients with duodenal ulcer disease.

Helicobacter pylori infection is present in most patients with duodenal ulcer disease, and cure of H pylori infection has been shown to dramatically reduce ulcer recurrence. Therapeutic strategies for duodenal ulcer disease have rapidly evolved over the past several years in an effort to consistently cure H pylori infection in a safe, cost-efficient manner. This paper reviews the effectiveness of treatments for H pylori infection in patients assessed with duodenal ulcer disease. The impact of clinical success on economic effectiveness has been determined in a recent prospective outcomes trial. Treatments with clarithromycin plus omeprazole or clarithromycin plus ranitidine-bismuth-citrate (RBC) provide consistent cure of H pylori infection, with eradication rates of 70% to 80%. Recent studies suggest that higher rates of eradication are possible with triple combination therapy (e.g., clarithromycin plus a second antibiotic and a proton pump inhibitor or RBC), but the optimal triple therapy regimen (including the combination of drugs, dosage, and duration of treatment) has not yet been defined. A recent 1-year prospective outcomes trial has demonstrated that eradication therapy with clarithromycin and omeprazole, compared with standard antisecretory therapy, provides measurable savings in utilization of ulcer-related health-care resources. Combination therapy with clarithromycin plus omeprazole, clarithromycin plus RBC, or clarithromycin plus lansoprazole and amoxicillin have been approved for the treatment of H pylori infection in patients with duodenal ulcer disease. Economic analysis has confirmed that cure of H pylori infection not only contributes to the clinical resolution of duodenal ulcer disease, but also provides economic advantages by reducing costs associated with recurrence.

Anti-Bacterial Agents↗
PubMed1997

The Pyloritek test and the CLO test: accuracy and incremental cost analysis.

OBJECTIVE: The aim of this study was to compare the Pyloritek test (a 1-h rapid urease test) to the widely used CLO test. METHODS: Seventy-one patients undergoing upper endoscopy were studied. All patients gave informed consent. A single antral biopsy specimen was obtained for the CLO test, and another was obtained for the Pyloritek test. Additional specimens were obtained for culture and processed in the event of a discordant result. The Pyloritek assay was read at 1 h by one observer. The CLO test was read at 24 h by an observer blinded to the results of the Pyloritek assay. RESULTS: There were 18 males and 53 females, and the mean age (+/- SEM) was 53 +/- 17 yr. Thirty-two patients had a positive result on the CLO test, and 39 had a negative test result. Of the 32 patients with a positive CLO test result at 24 h, 31 were positive by the Pyloritek test at 1 h. All 39 patients with negative CLO test results had negative Pyloritek test results as well. There was one discordant result, a negative Pyloritek test result and a positive CLO test result. Culture demonstrated growth of Helicobacter pylori. The kappa value, a measure of the reliability of the Pyloritek test compared with the CLO test, was 0.972 (SE, 0.0284; 95% confidence interval, 0.925-1). Marginal cost-effectiveness analysis favored the Pyloritek test. CONCLUSIONS: Results of the Pyloritek test at 1 h and the CLO test at 24 h are comparable in terms of detection of urease activity.

Adult↗
PubMed1997

Effect of push enteroscopy on transfusion requirements and quality of life in patients with unexplained gastrointestinal bleeding.

AIM: The aim of our study was to determine whether push enteroscopy altered transfusion requirements or quality of life in patients with unexplained gastrointestinal bleeding. METHODS: Twenty-nine patients with gastrointestinal bleeding unexplained by upper endoscopy and colonoscopy or persistent despite appropriate therapy after these procedures, underwent enteroscopy. Transfusion records in the year preceding and after the procedure were obtained from blood bank records and from telephone interviews every 6 months. RESULTS: Of 29 patients, 20 had received a transfusion (mean 8 +/- 3 units per patient) in the year preceding enteroscopy. In the year after the enteroscopy, 11 patients required transfusion (p = 0.034), and the mean transfusion requirement fell to 4 +/- 2 units, (p = 0.007). Angiodysplasia, the most frequent lesion found at enteroscopy (13 patients, 45%) were treated by endoscopic cautery. These patients had received an average of 13 +/- 6 units of packed cells per patient in the year preceding the procedure. In the year after enteroscopy, there was a significant reduction in transfusions (6 +/- 3 units per patient; p = 0.021). Of the 13 patients, 4 (31%) no longer required transfusions. Median functional status improved from 60 to 90 (p = 0.005). CONCLUSIONS: Enteroscopy alters the outcome of some patients with obscure gastrointestinal bleeding by reducing or eliminating bleeding and improving functional status.

Angiodysplasia↗
PubMed1996

The economics of eradicating Helicobacter pylori infection in duodenal ulcer disease.

Approximately 5 million people in the United States suffer from peptic ulcer disease, making this an important clinical problem. In addition to the huge costs associated with treatment, peptic ulcer disease also results in losses to industry as a result of loss of productivity. Infection with Helicobacter pylori is now accepted as the cause of duodenal ulcer in the majority of patients. Eradication of this infection leads to healing of the ulcer and prevents disease recurrence. A number of treatment regimens have been described for the eradication of H. pylori, but there is uncertainty regarding the optimum regimen to be used. Economic analyses allow an assessment of the probable costs associated with existing and new treatment strategies. In an era of increasing cost awareness, the results of such analyses are becoming increasingly important determinants of management strategies for the treatment of H. pylori infection.

Drug Resistance, Microbial↗
PubMed1996

A prospective trial of self-expanding metal stents in the palliation of malignant esophageal obstruction after failure of primary curative therapy.

BACKGROUND: Self-expanding metal stents have been shown to be safe and effective for the primary palliation of patients with inoperable malignant esophageal obstruction. We sought to determine their safety and efficacy in patients who fail curative therapy. METHODS: Seventeen patients with esophageal carcinoma who had recurrent dysphagia after radiation, surgery, or chemoradiation therapy for esophageal carcinoma were studied. All patients had recurrent dysphagia, and an uncovered metal stent was inserted for palliation. Patients were followed-up at 4-week intervals until death. Palliation was measured by a dysphagia score and the Karnofsky index. RESULTS: Seventeen patients with recurrent dysphagia after primary treatment with surgery (n = 4), radiation (n = 11), and chemoradiation (n = 2) received uncovered Wallstents for palliation of dysphagia. The dysphagia score improved by at least 1 point in all patients. Thirteen of 17 patients had a 2 point improvement in the dysphagia score. The Karnofsky index improved significantly (from 58 +/- 3 to 66 +/- 3, p = 0.0002). Fourteen of the 17 patients had patent stents until death. Three of 12 patients (25%) died of stent-related complications (bleeding in 1, septic complications in 2 patients). CONCLUSIONS: Patients with recurrence of esophageal carcinoma after surgery can be successfully treated with metal stents, but patients who have received radiation therapy with curative intent may be at greater risk for complications because of radiation-induced tumor necrosis and vascular changes in the esophageal wall. Larger prospective studies are necessary to clarify this issue.

Aged↗
PubMed1996

Human tissue responses to metal stents implanted in vivo for the palliation of malignant stenoses.

BACKGROUND: We sought to determine the histologic effects of metal stent placement on tumor tissue and on normal tissue proximal and distal to the tumor in patients with expandable metal stents implanted in vivo. METHODS: Twelve patients with 10 to 16 mm uncovered Wallstents were studied, 5 with esophageal stents, 4 with biliary stents and 3 with antral-duodenal stents. Stent duration ranged from 18 days to 15 months. Eleven autopsy specimens and one surgical specimen were examined. The organs with the stent in place were removed, and histologic specimens were obtained using a special saw-microtome that cuts through the tissue and the material of the stent. RESULTS: In all organs examined, the stent was incorporated into the material of the tumor to a varying degree. In the normal areas above and below the stenosis, the stent was incorporated into the wall of the organ and was covered by a collagenous reactive layer on the luminal aspect. The collagenous reaction was limited and did not cause exuberant growth or obstruction in any of the cases. CONCLUSIONS: The struts of uncovered Wallstents of 10 to 16 mm in diameter migrate into the submucus space above and below the tumor, probably by pressure necrosis, and become incorporated into the wall of the organ.

Aged↗
PubMed1996

Cost-effectiveness of treatment regimens for the eradication of Helicobacter pylori in duodenal ulcer.

BACKGROUND: Eradication of Helicobacter pylori with antimicrobials was recommended by a recent NIH consensus panel for all infected patients with peptic ulcer disease. The precise regimen that should be used for eradication of the infection remains uncertain because of the variety of regimens described, variable results with the regimens, and difficulties in predicting drug compliance outside clinical trials. METHODS: A decision analysis tree was developed with three regimens that are widely used regimens for the eradication of H. pylori: 1) 2-wk triple drug therapy (metronidazole, bismuth, tetracycline with H2 receptor antagonist), 2) 2-wk omeprazole and amoxicillin, and 3) 2-wk omeprazole and clarithromycin. Traditional H2 receptor antagonist therapy was used for comparison. A 2-yr time period was chosen for study to allow sufficient time for relapse and to evaluate its effect on the treatment strategy. Probabilities for eradication, compliance, and metronidazole resistance were determined from published data, and assumptions were tested by sensitivity analysis. RESULTS: Standard 2-wk triple drug therapy was the least expensive strategy ($720), and conventional H2 receptor antagonist therapy was the most expensive ($1791). Costs with 2-wk therapy with omeprazole and clarithromycin ($768) were lower than with omeprazole and amoxicillin ($1028). CONCLUSIONS: Treatment to eradicate H. pylori in infected patients with duodenal ulcer is a less expensive strategy than traditional therapy with H2 receptor antagonists. Triple drug therapy is the optimal regimen in areas where metronidazole resistance rates are < 36% and compliance is > 53%. Omeprazole and amoxicillin is not cost-effective unless eradication rates are greater than 74%. Dual drug therapy with omeprazole and clarithromycin is effective in regions where metronidazole resistance is high or where it is anticipated that there would be poor compliance with the more complicated triple drug therapy regimen.

Amoxicillin↗
PubMed1996

Enteroscopy. Outcomes.

Outcomes studies are important to determine the role of enteroscopy in the management of patients with obscure gastrointestinal bleeding. This article discusses the current available data and identifies areas for further research.

Endoscopes, Gastrointestinal↗
PubMed1995

Short- and long-term outcome of esophageal perforation.

Esophageal perforation is an important complication of endoscopy and dilation, but few data are available regarding long-term outcome in these patients. Thirty-one consecutive patients with esophageal perforation were studied. Long-term outcome was determined by office follow-up and questionnaires via mail or telephone. The study group included 16 men and 15 women with a mean age of 61 +/- 4 years. Instrumentation was the principal cause of perforation (77%), and pain was the principal symptom in the majority of cases. However, some patients reported no pain, their only symptom being shortness of breast or dysphagia on swallowing saliva. Contrast examinations were used to establish the diagnosis, but results were initially negative in 3 of 27 patients (11%). Seven patients were treated nonsurgically (nasogastric drainage, antibiotics, and intravenous alimentation). Fourteen patients underwent primary closure of the esophageal rent. Six patients underwent surgical drainage, 3 underwent total esophagectomy, and 1 died during surgery before the esophagus was exposed. Thirty-day mortality was 6.4%. Mean hospital stay was 26 +/- 5 days. Postdischarge follow-up was available in 28 of the 29 patients (97%) surviving initial hospitalization, and the mean follow-up was 47 +/- 9 months. Nineteen patients had persistent dysphagia, and 6 underwent dilation again. One of these patients had a second perforation. Contrary to results of some earlier studies, the mortality from esophageal perforation was low in our study because of early intervention in suspected cases. Results of contrast studies are sometimes negative in the early stages after perforation, and studies may need to be repeated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗