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Dive into the research topics where David S. Loeb is active.

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Featured researches published by David S. Loeb.


Gastroenterology | 2008

Prospective, Controlled Tandem Endoscopy Study of Narrow Band Imaging for Dysplasia Detection in Barrett's Esophagus

Herbert C. Wolfsen; Julia E. Crook; Murli Krishna; Sami R. Achem; Kenneth R. DeVault; Ernest P. Bouras; David S. Loeb; Mark E. Stark; Timothy A. Woodward; Lois L. Hemminger; Michael B. Wallace

BACKGROUND & AIMS High-resolution endoscopy with narrow band imaging (NBI) enhances the visualization of mucosal glandular and vascular structures. This study assessed whether narrow band targeted biopsies could detect advanced dysplasia using fewer biopsy samples compared with standard resolution endoscopy. METHODS We conducted a prospective, blinded, tandem endoscopy study in a tertiary care center with 65 patients with Barretts esophagus undergoing evaluation for previously detected dysplasia. Standard resolution endoscopy was used first to detect visible lesions. Narrow band endoscopy was then used by another gastroenterologist to detect and biopsy areas suspicious for dysplasia. The lesions initially detected by standard resolution endoscopy were then disclosed and biopsied, after biopsy of the lesions targeted with NBI. Finally, random 4-quadrant biopsies were taken throughout the segment of Barretts mucosa. RESULTS Higher grades of dysplasia were found by NBI in 12 patients (18%), compared with no cases (0%) in whom standard resolution white light endoscopy with random biopsy detected a higher grade of histology (P < .001). Correspondingly, narrow band directed biopsies detected dysplasia in more patients (n = 37; 57%) compared with biopsies taken using standard resolution endoscopy (n = 28; 43%). In addition, more biopsies were taken using standard resolution endoscopy with random biopsy compared with narrow band targeted biopsies (mean 8.5 versus 4.7; P < .001). CONCLUSIONS In patients evaluated for Barretts esophagus with dysplasia, NBI detected significantly more patients with dysplasia and higher grades of dysplasia with fewer biopsy samples compared with standard resolution endoscopy.


The American Journal of Gastroenterology | 2006

Barrett's esophagus is common in older men and women undergoing screening colonoscopy regardless of reflux symptoms.

Eric M. Ward; Herbert C. Wolfsen; Sami R. Achem; David S. Loeb; Murli Krishna; Lois L. Hemminger; Kenneth R. DeVault

BACKGROUND:Although Barretts esophagus (BE) is the precursor of esophageal adenocarcinoma (ACA), most patients with ACA present outside of a BE surveillance program. This could be due to undiagnosed symptomatic GER and BE or BE/ACA occurring in patients without reflux symptoms. We have, therefore, studied the prevalence of BE and symptom status in older patients referred for colonoscopy.METHODSAll patients referred for outpatient colonoscopy were eligible if they were at least 65 yr old and had not previously undergone esophagoscopy. After informed consent, the patients completed detailed GER questionnaires. During the research endoscopy, the endoscopist recorded the squamocolumnar junction (SCJ) as either long-segment BE (LSBE), short-segment BE (SSBE), or normal. If the SCJ was felt to be “irregular” the endoscopist was asked to predict, in their judgment, if BE was present. All patients had biopsies below the SCJ, which were examined by a gastrointestinal pathologist who was blinded to the endoscopic findings.RESULTSBE esophagus was present in 50 of the 300 patients studied (16.7%). BE was more common in men (35 of 161, 21.7%) than in women (15 of 139, 10.8%) (p < 0.025). GERD symptoms were reported in 106 patients (35%) and BE was present in 19.8% of symptomatic and 14.9% of asymptomatic cases (NS). The majority of the BE in this study was less than 3 cm in length (92%). The questionnaires did not predict the presence of BE.CONCLUSIONSBE is common in unscreened male and female patients at least 65 yr of age who are referred for colonoscopy. Men were more likely than women to have BE although it occurred in both sexes. Reflux symptoms were fairly common but a poor predictor of BE.


The American Journal of Gastroenterology | 2002

Colonoscopy in octogenarians: a prospective outpatient study

Frank Lukens; David S. Loeb; Victor I. Machicao; Sami R. Achem; Michael F. Picco

OBJECTIVES: The number of octogenarians (age ≥80 yr) referred for colonoscopy is increasing. Reported success rates regarding colonoscopy completion and adequacy of colonic preparation are poor overall in this group. This may be the result of age-related differences or biases due to retrospective data. The aims of this study were to prospectively determine differences between octogenarians and nonoctogenarians in adequacy of colonic preparation, success in completing colonoscopy, and complications of conscious sedation. METHODS: Prospective cohort study of 250 consecutive outpatients (150 nonoctogenarians and 100 octogenarians) referred for colonoscopy. Colonic preparation tolerance was assessed before colonoscopy, and the success rate and preparation were evaluated after the procedure. Conscious sedation complications were compared. RESULTS: In octogenarians and nonoctogenarians preparation tolerance (86% and 90%, respectively) was similar. Endoscopic success rate was slightly lower in octogenarians (90% vs 99%, p = 0.002). Preparation was poor in 16% of octogenarians compared with 4% of nonoctogenarians (p = 0.001). This was independent of the type of preparation used. Oxygen desaturation was more common in octogenarians (27% vs 19%, p = 0.0007) and associated with a higher meperidine dose (1.05 vs 0.75 mg/kg). No adverse outcomes occurred in either study group. CONCLUSIONS: Colonic preparations were well tolerated and colonoscopic success rates were high in octogenarians and nonoctogenarians. However, poor colonic preparation was four times as likely in octogenarians and was the most important impediment to adequate colonoscopy.


Mayo Clinic Proceedings | 2004

Complications of Endoscopy of the Upper Gastrointestinal Tract: A Single-Center Experience

Herbert C. Wolfsen; Lois L. Hemminger; Sami R. Achem; David S. Loeb; Mark E. Stark; Ernest P. Bouras; Kenneth R. DeVault

OBJECTIVE To evaluate prospectively the complications that occurred during consecutive endoscopies of the upper gastrointestinal tract. PATIENTS AND METHODS We evaluated all endoscopies of the upper gastrointestinal tract (except endoscopic retrograde cholangiopancreatography and endosonography) performed at the Ambulatory Surgical Center at the Mayo Clinic in Jacksonville, Fla, between January 1999 and June 2002. A staff gastroenterologist with or without a trainee performed these procedures. Therapeutic procedures included esophageal band ligation, injection sclerotherapy, botulinum toxin injection, extended upper endoscopy, pneumatic balloon dilation, endoscopic mucosal resection, and endoscopic ablation using thermal laser, argon beam coagulator, or photodynamic therapy. All complications were tabulated prospectively as per mandatory state licensure reporting. RESULTS Complications after diagnostic endoscopy of the upper gastrointestinal tract were related to anesthesia in 2 of the 12,841 patients. Perforations in 5 patients were associated with esophageal dilation (2), resection of duodenal lesions (2), or passage of a side-viewing instrument into the duodenum (1). No deaths occurred. CONCLUSIONS Diagnostic endoscopy of the upper gastrointestinal tract is safe, with a complication rate of less than 1 per 5000 cases. Therapeutic endoscopy increases the risk of complications. Compared with complication rates published previously, our results from a single center indicate a favorable reduction in complications related to endoscopy of the upper gastrointestinal tract.


The American Journal of Gastroenterology | 2006

Enhanced Magnification-Directed Biopsies Do Not Increase the Detection of Intestinal Metaplasia in Patients with GERD

Dawn D Ferguson; Kenneth R. DeVault; Murli Krishna; David S. Loeb; Herbert C. Wolfsen; Michael B. Wallace

BACKGROUND:The diagnosis of Barretts esophagus (BE) requires histologic confirmation of specialized intestinal metaplasia (SIM) through biopsy, a technique prone to sampling error. One method designed to improve the yield of biopsy uses acetic acid with magnification endoscopy: enhanced magnification endoscopy (EME). This technique identifies several mucosal surface patterns, and of these, pattern types III and IV have been associated with SIM.METHODS:We conducted a prospective, randomized trial to compare EME-directed biopsies and standard endoscopy with random biopsies in patients with symptoms of gastroesophageal reflux disease. Patients in the standard endoscopy group with evidence of BE had four-quadrant random biopsies taken every 2 cm. If there was no BE, four-quadrant biopsies were taken at the SCJ. Patients in the EME group had the mucosa at the SCJ classified as type I–IV based on published criteria. Biopsies targeted to type III and IV were compared to random biopsies.RESULTS:One hundred thirty-seven patients enrolled (68 randomized to EME, 69 to standard endoscopy). Fifty-six (41%) had endoscopic evidence of BE (20 standard endoscopy [29%] vs 36 EME [53%]). Of the patients with apparent BE, standard endoscopy with random biopsies confirmed SIM in 12 (60%) compared to 11 of 18 (61%) patients with EME targeted biopsies of patterns type III or IV (p = 1.0). Patients without apparent BE (N = 81) had SIM of the SCJ confirmed in 16% (8 of 49) with standard endoscopy and random biopsies compared with 8% (1 of 12) using EME-directed biopsy of pattern III or IV (p = 0.67).CONCLUSIONS:Random biopsies of endoscopically apparent BE and a normal SCJ yield SIM at the same rate as targeted biopsies with EME in patients with pattern types III or IV. This calls into question the utility of this technique in reducing sampling error to identify SIM.


Clinical Gastroenterology and Hepatology | 2005

A Randomized Trial of Endoscopic Biliary Sphincterotomy Using Pure-Cut Versus Combined Cut and Coagulation Waveforms

Ian D. Norton; Bret T. Petersen; Jay Bosco; Doug B. Nelson; Peter B. Meier; Todd H. Baron; Stephen M. Lange; Christopher J. Gostout; David S. Loeb; Michael J. Levy; Maurits J. Wiersema; Nicole L. Pochron

BACKGROUND & AIMS Endoscopic biliary sphincterotomy has complication rates of 5%-12%. The output from the electrosurgical generator may influence the degree of coagulation and the rapidity of the incision, and thus rates of pancreatitis, hemorrhage, and perforation. Some modern generators incorporate feedback control to standardize output and automate the alternating cut and coagulation modes. Our aim was to compare 2 feedback-controlled generators, one with constant pure cutting-type output and the other with an alternating cut and coagulation mode. METHODS In this multicenter randomized study, 133 patients were assigned to the alternating cut/coag output and 134 patients were assigned to constant pure-cut output. Patients were stratified by their risk for pancreatitis. RESULTS The overall pancreatitis rate was 1.5%, including 3 patients in the cut/coag group and 1 patient in the pure-cut group (P>.05). There were 11 poorly controlled (zipper) incisions in the pure-cut group and none in the cut/coag group (P=.02). The incision was completed in all patients without stalling. Immediate hemorrhage occurred in 35 pure-cut patients and 8 cut/coag patients output (P=.002). There were no episodes of clinically significant bleeding, delayed bleeding, or perforation. CONCLUSIONS Biliary sphincterotomy using feedback-controlled generators results in dependable progression of incision with a low pancreatitis rate. Control of the incision is improved subjectively with the cut/coagulation output, but this did not translate into a difference in clinically significant complications.


Mayo Clinic Proceedings | 1992

Management of Gastroduodenopathy Associated With Use of Nonsteroidal Anti-Inflammatory Drugs

David S. Loeb; David A. Ahlquist; Nicholas J. Talley

Adverse events associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) are reported more frequently to the Food and Drug Administration than are those associated with any other group of drugs. The absolute risk for serious gastrointestinal events--in particular, ulcer bleeding, perforation, and death--is controversial; some investigators believe that an epidemic of NSAID-related complications is being experienced, whereas others suggest that the risks are being overemphasized. The management of patients who take NSAIDs regularly also remains controversial. Key unresolved issues include how best to identify those patients at particularly high risk for the development of ulcer complications and whether such patients should receive prophylactic therapy in an attempt to prevent such problems. In this review, we critically evaluate the currently available literature and present a management algorithm for the treatment and prevention of NSAID-associated gastroduodenopathy.


The American Journal of Gastroenterology | 2005

Pneumomediastinum following Enteryx injection for the treatment of gastroesophageal reflux disease.

Kyung W. Noh; David S. Loeb; Andrew H. Stockland; Sami R. Achem

We describe the case of a 68-year-old female who developed pneumomediastinum following the “Enteryx” procedure for the treatment of gastroesophageal reflux disease (GERD). The patient required hospitalization and parenteral antibiotics and responded favorably to a conservative approach. Similar complications have been observed with other endoscopic treatment modalities for GERD such as Stretta and suturing techniques. Our patient represents the third reported case of a serious complication after Enteryx implantation.


The American Journal of Gastroenterology | 1999

Hodgkin's disease of the esophagus: report of a case

David S. Loeb; Afonso Ribeiro; David M. Menke

Most esophageal malignancies are either squamous carcinomas or adenocarcinomas arising in the background of Barretts esophagus. We describe a case of an 85-yr-old woman in whom the diagnosis of esophageal malignancy was difficult to confirm despite its endoscopic appearance and previous biopsies. This case illustrates the difficulty in diagnosing Hodgkins disease of the esophagus. Despite the rarity of this entity, if clinically indicated by symptoms, large, deep biopsies by rigid esophagoscopy should be considered.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2003

Resource Utilization and Procedure Parameters for the Stretta Procedure: Comparison with Endoscopic Ultrasonography and Colonoscopy

Herbert C. Wolfsen; Lois L. Hemminger; Mark E. Stark; Sami R. Achem; David S. Loeb; Timothy A. Woodward; Kenneth R. DeVault

BACKGROUND No data are available regarding resource utilization of the Stretta procedure and its impact on endoscopy units in comparison with other endoscopy procedures. METHODS This observational cohort study compared the demographic data and procedural parameters for our first 13 cases undergoing the Stretta procedure, with similar endoscopic colonoscopy and ultrasonography (EUS) cases. RESULTS The characteristics of the patients were similar among these groups. The patients undergoing the Stretta procedure required significantly more sedative medication than those undergoing colonoscopy or EUS. The Stretta procedure time and recovery time were significantly longer than the colonoscopy procedure time and recovery time. The Stretta procedure time was also significantly longer than the EUS procedure time, but the Stretta recovery time was not significantly longer than the EUS recovery time. CONCLUSIONS Although this study is small and not randomized, it provides useful information regarding how endoscopic procedures compare with one another. Furthermore, these findings have implications for determining endoscopy unit staffing, work equivalency, and appropriate reimbursement.

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