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Biomedical subjects

M B Fennerty

Publications and source records attributed to M B Fennerty.

At least 109 records · Page 6Linked to original sources
PubMed1993

Are endoscopic measurements of colonic polyps reliable?

Many clinical studies of colorectal adenomatous polyps rely on endoscopic estimation of polyp size. To examine the reliability of such measurements, we conducted a study using artificial polyps in an endoscopy teaching model. Eight experienced endoscopists estimated the size of 13 polyps in two separate sessions 2 wk apart. Endoscopic estimates of polyp size tended to be significantly lower than the true polyp size for all polyps and all endoscopists at both sessions. We also found a statistically significant difference in the magnitude of the underestimation between the first and second session (p < 0.0001). At the first session, polyps tended to be estimated at 64% of their true size, and at the second session, the estimates tended to be at 77% of the actual polyp size. We estimate the magnitude of the variation in polyp measurements due to individual polyps, endoscopist, and examination session, and discuss the impact these sources of variation have in planning of clinical trials.

Colonic Neoplasms↗
PubMed1992

Preventing hypoxemia during colonoscopy. A randomized controlled trial of supplemental oxygen.

Hypoxia as measured by pulse oximetry is well recognized in patients undergoing colonoscopy. A single trial of supplemental oxygen therapy has been shown to diminish the observed desaturation during colonoscopy. We further defined the role of supplemental oxygen during colonoscopy in a randomized controlled trial. Ninety-four patients undergoing routine colonoscopy were randomized to oxygen (2 L by nasal prongs) or placebo (nasal prongs only) arms. The physician and patients were blinded to which arm they were in. Sixty-four percent of patients in the placebo arm desaturated (less than 90% saturation) versus 29% in the treatment arm (p less than 0.001). There were no complications observed in either arm. We conclude that supplemental oxygen will decrease but not prevent the incidence of arterial desaturation observed during colonoscopy.

Aged↗
PubMed1992

Effectiveness of India ink as a long-term colonic mucosal marker.

We prospectively studied the use of India ink as a long-term or "permanent" mucosal marker as part of a study investigating the natural history of diminutive distal colorectal polyps. Twenty-six patients had 32 India ink tatoos implanted. The tatoo sites of the 19 patients who were followed at least 6 months continued to display intensely stained mucosa at the original sites. No side effects or complications were encountered. India ink appears to be a safe and effective long-term marker for colonic mucosal lesions.

Carbon↗
PubMed1992

Chemopreventive studies in Barrett's esophagus: a model premalignant lesion for esophageal adenocarcinoma.

Barrett's esophagus is a premalignant lesion in which the lower esophagus is lined with metaplastic columnar epithelium rather than the normal stratified squamous epithelium. It is a precursor lesion for adenocarcinoma of the esophagus. We are studying Barrett's esophagus as a model premalignant lesion for adenocarcinoma from the standpoint of identifying biologic markers of increased cancer risk as well as therapeutic strategies for eradicating the lesion. Ornithine decarboxylase (ODC) activity in Barrett's mucosa was significantly higher than in normal adjacent mucosa from the same patient. However, polyamine content was not significantly altered, suggesting dysregulation of the polyamine pathway. Flow cytometry is being used to assess the presence of aneuploidy and its significance in a premalignant lesion. Initial results have demonstrated that aneuploidy and dysplasia can be discordant. Cytogenetic analysis using short-term epithelial cultures established from endoscopic biopsies of the lesion has demonstrated the presence of clonal karyotypic abnormalities. The clinical significance of aneuploidy and abnormal karyotype, however, remains to be proved. Chemopreventive intervention trials have included use of 13-cis-retinoic acid. Considerable toxicity was encountered, and the lesion showed no change in extent in 11 evaluable patients. A subsequent clinical trial with a biologic endpoint used alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ODC, to test whether a low dose could produce changes in polyamine content in gastrointestinal mucosa.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1992

Peroral cholangioscopy with intracorporeal electrohydraulic lithotripsy for choledocholithiasis.

Five patients with choledocholithiasis refractory to standard extraction methods after endoscopic sphincterotomy underwent peroral cholangioscopy with the "mother-daughter" endoscopy system. electrohydraulic lithotripsy of nine stones was performed successfully and without complication, other than minor transient bleeding in one patient. The outer sheath of the "daughter scope" sustained a linear burn in one instance. This method of stone fragmentation is a useful adjunct to achieve ductal clearance in difficult cases.

Adult↗
PubMed1991

Referral patterns and the results of antireflux operations in patients more than sixty years of age.

The role of antireflux operations in the elderly is ill-defined. Often, these patients are managed medically despite refractory symptoms for fear of surgical morbidity and mortality by referring physicians. This investigation was done to review the referral patterns and results of antireflux operations for patients more than 60 years old. The charts of all patients undergoing operation for reflux were reviewed during an eight year period from 1981 to 1989. One hundred and three patients underwent Nissen fundoplication. All patients had been treated with H2 blockers or antacids, or both, prior to referral for operation. Group 1 (N = 43) consisted of all patients who were 60 years of age and group 2 (N = 60), all patients less than 60 years of age. The mean age of those in group 1 was 70.6 years versus 43.7 years for those in group 2. The mean duration of symptoms was far greater in the elderly group versus the younger group (14.4 versus 4.1 years) (p less than 0.001). Twenty-eight patients in group 1 were referred for surgical treatment because of complications of reflux versus only four in group 2 (p less than 0.01) in whom intractability was the main indication for surgical treatment. The specific complications of gastroesophageal reflux disease that led to the referral of elderly patients for operation were stricture, bleeding, aspiration and Barrett's esophagus. There was one death and this occurred in a 46 year old woman who had a massive pulmonary embolism postoperatively. The mean duration of follow-up study was 5.1 years. Improvement in symptoms was noted by 37 patients in group 1 versus 56 in group 2. We conclude that elderly patients are most often referred for antireflux operations for complications of reflux versus younger patients in whom intractability is the most common indication. Earlier referral is warranted if reflux symptoms persist despite adequate medical therapy. Despite advanced esophageal disease, the results of antireflux operations are good, and surgical morbidity and mortality rates are low enough to warrant intervention in this group of patients, provided no medical contraindications exist.

Adult↗
PubMed1990

Prospective study of the frequency and size distribution of polyps missed by colonoscopy.

An important determinant in interpreting the results of colorectal polyp chemoprevention trials is the rate of polyps missed during colonscopic examination. We prospectively examined 90 patients by tandem colonoscopy performed by two alternating examiners. In 69 (76.7%) patients, 221 neoplastic lesions were documented histologically. Of a total of 58 lesions detected in 31 patients, no neoplastic lesion greater than or equal to 10 mm in size was missed; 16% of diminutive (less than or equal to 5 mm) neoplastic polyps and 12.3% of medium-sized (6-9 mm) neoplastic polyps were missed by the first examiner. We conclude that an experienced colonoscopist will miss about 15% of colorectal neoplastic polyps less than 10 mm in size in the setting of adequate bowel preparation. Large (greater than or equal to 10 mm) polyps were rarely missed, however, with the "miss" rate in our study equal to 0, with a 95% confidence limit of 4.64%.

Adult↗
PubMed1990

Lack of impact of therapy on extent of Barrett's esophagus in 67 patients.

Sixty-seven patients with Barrett's esophagus have been prospectively followed over an average of 36 months (range 6 to 76 months) with standardized endoscopic observation and biopsies of the length of columnar epithelium. The initial length of Barrett's epithelium ranged from 1 to 16 cm, mean 5.5 cm. Specialized columnar epithelium was present in 64 of the 67 patients. Patients were treated predominantly with H2-receptor blocker therapy to relieve symptoms. Eighty-two percent of patients had less than a 1-cm change in length per year. The mean rate of change of length was -0.093 cm per year. These results confirm in a relatively large, prospective study that standard antireflux therapy for Barrett's esophagus does not result in consistent reduction in the extent of Barrett's epithelium over a three-year interval.

Adult↗
PubMed1990

Esophageal perforation during pneumatic dilatation for achalasia: a possible association with malnutrition.

Pneumatic balloon dilatation of the lower esophageal sphincter is commonly utilized as primary therapy for achalasia. Perforation related to pneumatic dilatation is uncommon (2-6%) but may result in severe morbidity. Factors associated with risk of perforation are not well defined. We noted perforation in three patients undergoing forceful balloon dilatation. All these patients had clinical evidence of significant malnutrition (recent marked weight loss and severe hypoalbuminemia). Malnutrition may be a causal factor for perforation in patients with achalasia undergoing dilatation.

Adolescent↗
PubMed1989

Discordance between flow cytometric abnormalities and dysplasia in Barrett's esophagus.

Eighty-six specimens from 25 patients with Barrett's epithelium were analyzed by both histology and flow cytometry. Of these, 73 were without dysplasia and 13 had dysplasia (7 low grade, 6 high grade). Eight of the nondysplastic specimens were aneuploid and another 15 had increased G2. Among the dysplastic specimens, two were aneuploid and two had increased G2. These data were grouped into four classifications: type 1 (65 specimens), specialized columnar epithelium (Barrett's) without dysplasia and no aneuploidy; type 2 (8 specimens), Barrett's epithelium without dysplasia and an aneuploid cell population; type 3 (11 specimens), Barrett's epithelium with dysplasia and no aneuploidy; and type 4 (2 specimens), Barrett's epithelium with dysplasia and aneuploidy. Distribution by type was 76%, 9%, 13%, and 2%, respectively. We conclude that histologic dysplasia and aneuploidy are often discordant. They may identify separate subgroups at risk, or when concordant, may reflect an increased cancer risk in that population. Further study will define the role of histology and flow cytometry in the screening and management of patients with Barrett's esophagus.

Adult↗
PubMedDate not supplied

A comparison of 10 and 14 days of lansoprazole triple therapy for eradication of Helicobacter pylori.

BACKGROUND: Data from large, multicenter, US studies determining the efficacy of triple therapy for the eradication of Helicobacter pylori are lacking, especially for a treatment duration of less than 14 days. METHODS: Patients with H pylori infection and active duodenal ulcer disease or a history of duodenal ulcer disease within the past year were randomized to receive 30 mg of lansoprazole, 1 g of amoxicillin, and 500 mg of clarithromycin twice daily for 10 or 14 days. The primary efficacy end point was the eradication of H pylori as confirmed by negative histological and culture results at 4 to 6 weeks after the completion of treatment. RESULTS: Of 284 patients enrolled in the study from 46 US sites, 236 met the entry criteria. At 4 to 6 weeks after the end of therapy, H pylori was eradicated in 85% (96/ 113) of the patients receiving 14-day triple therapy and in 84% (103/123) of those receiving 10-day triple therapy by per-protocol analysis (95% confidence interval for treatment group differences, -10.5 to 8.1; P>.05). There was also no significant difference between the 14- and 10-day treatment groups when analyzed by an intent-to-treat analysis of H pylori eradication. A similar proportion of patients in each treatment group reported an adverse event related to therapy (34% [46/136] vs 38% [56/148], respectively). CONCLUSIONS: In patients with an active or a recent history of duodenal ulcer, lansoprazole-based triple therapy for 10 or 14 days is highly effective in the eradication of H pylori. The duration of therapy may be reduced from 14 to 10 days without a significant effect on regimen efficacy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMedDate not supplied

Physiologic changes during colonoscopy.

We prospectively evaluated multiple physiologic parameters in 104 consecutive unselected patients undergoing elective colonoscopy. Changes observed during colonoscopy were then correlated with the type of anesthesia and level of sedation, position of the endoscope and presence of looping, existence of comorbid medical conditions, concomitant medication usage, and the occurrence of endoscopy induced pain. Clinically important changes in O2 saturation (54%) and in blood pressure (44%) were most frequently noted. Less frequent were changes in pulse (15%) or respiratory rate (4%). These clinically significant changes were associated with induction of anesthesia or endoscope looping and pain in 58 to 62% of the patients. In the remainder of patients, no obvious factor was associated with the observed alterations in physiologic parameters. There was no correlation with presence of comorbid medical conditions, use of concurrent medication, dose of anesthesia, level of sedation, and/or colon segment reached by the endoscope. Although there was no apparent morbidity associated with the induced changes in physiologic parameters, these data suggest that certain patients may be at increased risk of procedure-related morbidity and support the need for physiologic monitoring in high-risk patients.

Adult↗
PubMedDate not supplied

Prospective blinded trial of the colonoscopic miss-rate of large colorectal polyps.

We prospectively studied the colonoscopic miss-rate of large colorectal polyps in a blinded trial featuring tandem colonoscopy. Sixty-three lesions greater than or equal to 1 cm in size were discovered and none were missed. Confidence intervals of 95% are a miss-rate of 0 to 4.6%. We conclude that less than 5% of large colorectal polyps are missed during the index colonoscopic examination in a well-prepared colon.

Aged↗