PubMed Health⌕ Search

Biomedical subjects

S B Benjamin

Publications and source records attributed to S B Benjamin.

At least 19 recordsLinked to original sources
PubMed1998

Prospective study of somatostatin receptor scintigraphy and its effect on operative outcome in patients with Zollinger-Ellison syndrome.

OBJECTIVE: To determine the relative abilities of somatostatin receptor scintigraphy (SRS) and conventional imaging studies (computed tomography, magnetic resonance imaging, ultrasound, angiography) to localize gastrinomas before surgery in patients with Zollinger-Ellison syndrome (ZES) subsequently found at surgery, and to determine the effect of SRS on the disease-free rate. SUMMARY BACKGROUND DATA: Recent studies demonstrate that SRS is the most sensitive imaging modality for localizing neuroendocrine tumors such as gastrinomas. Because of conflicting results in small series, it is unclear in ZES whether SRS will alter the disease-free rate, which gastrinomas are not detected, what factors contribute to failure to detect a gastrinoma, or whether the SRS result should be used to determine operability in patients without hepatic metastases, as recently recommended by some investigators. METHODS: Thirty-five consecutive patients with ZES undergoing 37 exploratory laparotomies for possible cure were prospectively studied. All had SRS and conventional imaging studies before surgery. Imaging results were determined by an independent investigator depending on surgical findings. All patients underwent an identical surgical protocol (palpation after an extensive Kocher maneuver, ultrasound during surgery, duodenal transillumination, and 3 cm duodenotomy) and postoperative assessment of disease status (fasting gastrin, secretin test imaging within 2 weeks, at 3 to 6 months, and yearly), as used in pre-SRS studies previously. RESULTS: Gastrinomas were detected in all patients at each surgery. Seventy-four gastrinomas were found: 22 duodenal, 8 pancreatic, 3 primaries in other sites, and 41 lymph node metastases. The relative detection order on a per-patient or per-lesion basis was SRS > angiography, magnetic resonance imaging, computed tomography > ultrasound. On a per-lesion basis, SRS had greater sensitivity than all conventional studies combined. SRS missed one third of all lesions found at surgery. SRS detected 30% of gastrinomas < or =1.1 cm, 64% of those 1.1 to 2 cm, and 96% of those >2 cm and missed primarily small duodenal tumors. Tumor size correlated closely with SRS rate of detection. SRS did not increase the disease-free rate immediately after surgery or at 2 years mean follow-up. CONCLUSIONS: SRS is the most sensitive preoperative imaging study for extrahepatic gastrinomas in patients with ZES and should replace conventional imaging studies as the preoperative study of choice. Negative results of SRS for localizing extrahepatic gastrinomas should not be used to decide operability, because a surgical procedure will detect 33% more gastrinomas than SRS. SRS does not increase the disease-free rate. In the future, more sensitive methods to detect small gastrinomas, especially in the duodenum and in periduodenal lymph nodes, or more extensive surgery will be needed to improve the postoperative disease-free rate in ZES.

Adult↗
PubMed1997

A new system for defining endoscopic complications emphasizing the measure of importance.

BACKGROUND: Currently, there are no satisfactory systems for defining, classifying, and/or scoring endoscopic complications, although it would be important for quality assurance, comparative studies, and outcomes research. Recently the term "negative outcomes" was proposed rather than "complications," and an approach that incorporates "measures of importance" was added to compare negative outcomes. METHODS: A system was developed that defines, classifies, and grades negative outcomes with a scoring system based on measures of importance. Information was recorded on a Morbidity and Mortality (M & M) form, which was used at a monthly quality assurance (M & M) conference. Several measures of importance related to the immediate negative outcome (O) were quantified (effect of the complication on completion of the endoscopy, change in level of care, change in number of hospital days, necessity for new invasive procedures). The disability (D), defined as a residual or chronic negative outcome caused by the complication, was characterized and scored. Death (D) was also characterized, the value varying with circumstances. As a quantitative measure, an overall ODD score was used. RESULTS: One hundred twenty-three negative outcomes were retrospectively classified using the new M & M form and the ODD score was applied for 117 complications. Complications were ranked according to the ODD score. CONCLUSION: A system for defining, classifying, and grading negative outcomes of endoscopic procedures is proposed with a quantitative scoring system that emphasizes measures of importance. The ODD score looks at the immediate negative outcome and also the separate long-term issues of disability and death.

Documentation↗
PubMed1997

Silicone-covered Wallstent prototypes for palliation of malignant esophageal obstruction and digestive-respiratory fistulas.

BACKGROUND: Endoscopic palliation of malignant esophageal obstruction with uncovered self-expanding metal stents has been shown to have fewer complications than with conventional plastic stents. The addition of a membrane might prevent tumor ingrowth and allow treatment of digestive-respiratory fistulas. We report the clinical experience with a prototype silicone membrane-covered self-expanding metal stent. METHODS: Twenty-three silicone membrane-covered Wallstent prototypes were used in 21 patients with dysphagia due to inoperable malignant tumors involving the esophagus and cardia. RESULTS: Stent implantation was technically successful in all patients. There were no procedure-related perforations or deaths. The prototype stent was successful in sealing seven of the eight (87.5%) digestive-respiratory fistulas. As a group, the mean dysphagia grade improved significantly after stent placement (4.8 +/- 0.9 vs 3.4 +/- 1.6, p < 0.0005). However, 9 of 21 (42.9%) patients experienced no improvement in their dysphagia. Complications occurred in 13 of 21 (61.9%) patients. Tumor ingrowth was not observed in any patient. CONCLUSIONS: The prototype covered self-expanding metal stent was effective in sealing digestive-respiratory fistulas and provided palliation of dysphagia in slightly more than one half of the patients studied. A great deal has been learned from the preliminary experience, which has led to design modifications. The utility of the commercially available device should be evaluated in further prospective clinical trials.

Adult↗
PubMed1996

Flumazenil reversal of psychomotor impairment due to midazolam or diazepam for conscious sedation for upper endoscopy.

BACKGROUND: Flumazenil is a competitive benzodiazepine antagonist that acts to reverse their sedative and hypnotic effects. It is indicated in the management of benzodiazepine overdose, but its role in the routine reversal of endoscopic conscious sedation has not been defined. METHODS: Patients undergoing diagnostic upper endoscopy who received sedation with either diazepam or midazolam alone were given flumazenil 0.2 mg incrementally immediately following the procedure until awake. They were then asked to repeat three psychomotor tests measuring cognitive and motor skills, with their baseline scores compared with postprocedure scores over a 3-hour period. RESULTS: Full psychomotor function was restored to baseline values within 30 minutes after flumazenil in 79% of patients, with no differences in the reversal of psychomotor skill impairment observed between diazepam and midazolam sedation. There was no evidence of rebound sedation seen for up to 3 hours. No significant anterograde amnesia was evident in 78% of individuals. CONCLUSIONS: These results demonstrate that flumazenil's effects on reversing psychomotor impairment are similar when midazolam or diazepam are used for conscious sedation. However, the potential usefulness of routine flumazenil reversal of conscious sedation will require further evaluation of specific psychomotor performance skills (such as driving a car) before we lift the admonition against leaving the endoscopic suite unattended, driving a vehicle, or operating complicated machinery for several hours.

Adult↗
PubMed1996

High-resolution chromoendoscopy for the diagnosis of diminutive colon polyps: implications for colon cancer screening.

BACKGROUND & AIMS: A visual, nonbiopsy technique that could reliably determine the histology of diminutive colorectal polyps could greatly reduce the cost of colon cancer screening. This study was designed to report our experience using a high-resolution colonoscope combined with indigo carmine dye to diagnosis diminutive colorectal polyps. METHODS: Colonoscopy using a Fujinon EC-400 HM/HL was performed in 36 patients with polyps <10mm in diameter. Polyps from the first 12 patients (phase 1) were sprayed with 10 mL of 0.2% indigo carmine dye, and a biopsy was performed or a specimen removed and submitted for histological analysis. The morphological data were used to predict polyp histology in the subsequent 24 patients (phase 2). RESULTS: Hyperplastic polyps had a characteristic surface "pit pattern" of orderly arranged "dots" that resembled the surrounding, nonpolypoid mucosa. Adenomatous polyps had surface "grooves" or "sulci." Sensitivity and specificity of our techniques in distinguishing adenomatous from nonadenomatous colorectal polyps were 93% and 95% respectively. CONCLUSIONS: High-resolution chromoendoscopy provides morphological detail of diminutive colorectal polyps that correlates well with polyp histology. If incorporated into colon cancer screening, these techniques may limit the need for biopsy and/or subsequent colonoscopy and ultimately decrease costs.

Adult↗
PubMed1996

Complications of conscious sedation.

Complications are a part of the practice of medicine. This is amply true for gastrointestinal endoscopy. The medications currently used in the practice of gastrointestinal endoscopy are essential to our ability to perform the wide array of diagnostic and therapeutic procedures that have become the hallmark of modern day gastroenterology. As in all of medicine, a decision is based on an assessment of risk versus benefit. Yes, these medications do carry risk with their use; however, with proper preparation and careful administration, the benefits derived far exceed the risks. We are able to perform a host of endoscopic surgical procedures precluding higher risk alternatives; patients are saved the anxiety and discomfort associated with the procedure and, in situations where follow-up procedures are necessary, they usually are more than willing to return. Maintaining these gains is the responsibility of the gastrointestinal endoscopist community and requires the recognition of the risks and a continuous effort to minimize them.

Analgesia↗
PubMed1996

Gastric polyps: relationship of size and histology to cancer risk.

OBJECTIVES: Management of gastric polyps based on polyp size (< or > 2 cm), and histology obtained from forceps biopsy sampling is controversial. To illuminate this subject, the 4-yr experience with endoscopic management of gastric epithelial polyps at a university hospital and a Veterans Administration medical center was reviewed with histopathologic correlation. METHODS: A computer data-base was used to recall the endoscopic diagnosis of "gastric polyp." Endoscopy reports, video, and still photography were reviewed for data on polyp appearance, size, location, and management. These data had been entered prospectively as required by the Computer-Based Management System. Histopathology was reviewed by a second, blinded, pathologist. Gastric polyps of epithelial origin, at least 0.5 cm in diameter, and not associated with polyposis syndromes, were included. RESULTS: Thirty-five gastric polyps in 23 patients met inclusion criteria. Snare polypectomy was ultimately performed on 26, and complete resection with forceps biopsy alone on 9. On histopathology 31 polyps were hyperplastic and 4 were adenomas. Six hyperplastic polyps contained focal dysplasia. Among these, carcinoma in situ was identified in three, all <2.0 cm. Furthermore, forceps biopsy in two of these did not reveal the dysplastic components. One adenomatous polyp also contained carcinoma, also <2.0 cm. CONCLUSIONS: These data emphasize that management based on polyp size or histology obtained from forceps biopsy sampling may be faulty. We recommend that gastric polyps >0.5 cm be removed in toto.

Adenocarcinoma↗
PubMed1996

Video-laparoscopic reduction of an intrathoracic stomach.

A paraesophageal hiatal hernia is caused by a defect in the anterolateral aspect of the diaphragmatic esophageal hiatus. Most commonly, the stomach migrates into the hernia sac. Although most patients are asymptomatic, repair is advised at the time of the diagnosis because of the high morbidity and mortality associated with surgery for the complications of paraesophageal hiatal hernias. However, because of the morbidity associated with conventional surgical techniques, there has been great reluctance to subject an asymptomatic patient to surgical repair. We report a minimally invasive technique for the reduction of a paraesophageal hiatal hernia and repair of the diaphragmatic hiatal defect. Video laparoscopy, with its attendant low morbidity, may be the ideal technique for the repair of paraesophageal hiatal hernias.

Female↗
PubMed1995

Functional evidence for the presence of nitric oxide synthase in the dorsal motor nucleus of the vagus.

BACKGROUND & AIMS: Histochemical studies indicate that reduced nicotinamide adenine dinucleotide phosphate diaphorase, the nitric oxide synthase-related enzyme, is present in the dorsal motor nucleus of the vagus of the cat. We have previously shown in vitro that NO synthase is present in this nucleus in the rat and that the excitatory effect of N-methyl-D-aspartate on these neurons is in part caused by NO formation. The aim of this study was to obtain functional evidence for the presence of NO synthase in the cat dorsal motor nucleus of the vagus. METHODS: L-Glutamate, L-arginine, D-arginine, the NO donor S-nitroso-N-acetyl-penicillamine, and the NO synthase inhibitor NG-nitro-L-arginine-methyl ester were unilaterally microinjected into the rostral dorsal motor nucleus of anesthetized cats, and antral and pyloric motility were monitored using extraluminal force transducers. RESULTS: Microinjection of L-arginine increased gastric motility, whereas D-arginine had no effect. Vagotomy eliminated the L-arginine-induced increases. Microinjection of S-nitroso-N-acetyl-penicillamine increased antral motility. NG-Nitro-L-arginine-methyl ester prevented L-arginine from exerting an effect on gastric motility. CONCLUSIONS: Motility increases obtained after microinjection of L-arginine into the dorsal motor nucleus and prevention of these motility increases with microinjection of a NO synthase inhibitor provide functional evidence for the presence of NO synthase in the dorsal motor nucleus of the vagus in the cat.

Animals↗
PubMed1995

Endoscopic ultrasound for staging esophageal cancer, with or without dilation, is clinically important and safe.

BACKGROUND: To fully evaluate patients with esophageal cancer by endoscopic ultrasonography (EUS), the transducer must pass through the entire tumor to the cardia to scan the celiac axis. Dilation may be necessary. Published information suggests that dilation with EUS carries a sizeable risk. METHODS: In order to assess the complication rate associated with dilation prior to EUS in patients with esophageal cancer and the clinical significance of dilation for complete EUS staging, we reviewed the records of all patients who had undergone EUS for esophageal cancer. RESULTS: Sixty-three patients underwent EUS staging of esophageal cancer. Thirty-nine (62%) had lesions through which the EUS scope was passable (Group I). Ten (16%) patients (Group II) had lesions through which an EUS scope (diameter 13 mm) was unable to pass even after dilation. Fourteen patients (22%) had lesions that were dilated to allow passage of the EUS scope (Group III). All patients in Groups II and III had confirmation of EUS staging by CT and/or surgery. In Group II, five patients had tumors defined as T4 (50%) and five as T3 (50%). In Group III, nine (64%) had T4 tumors, four (29%) had T3, and one (7.7%) had T2. No complications were encountered in any group. CONCLUSION: EUS, either alone or after dilation, is a safe procedure and the complete EUS examination with celiac node visualization adds prognostically significant information.

Adult↗
PubMed1995

Dietary fat modulates gastric lipase activity in healthy humans.

The aim of this study was to determine whether the amount of dietary fat modulates the activity of gastric lipase in humans. Gastric juice was collected from six healthy subjects after 2-wk periods of either a high-fat (50% of energy as fat) or low-fat (25% of energy as fat) diet. The collection period lasted 2 h, the first hour under baseline conditions and the second hour after pentagastrin stimulation (6 micrograms/kg body wt). Gastric lipase and pepsin activities were quantitated at 15-min intervals and total enzyme outputs were calculated. Under baseline conditions there was a tendency for higher output of gastric lipase and pepsin after the high-fat diet than after the low-fat diet (gastric lipase: 745 compared with 446 U/h, pepsin: 107,677 compared with 78,505 U/h). The difference in output between diet groups was significant after pentagastrin stimulation (gastric lipase: 1323 compared with 875 U/h, pepsin: 191,751 compared with 128,961 U/h, for high-fat compared with low-fat diet, respectively, P < 0.05). This study is the first to report that a high-fat diet leads to an increase in the activity of gastric enzymes in humans.

Adaptation, Physiological↗
PubMed1995

Esophageal function and occurrence of Barrett's esophagus in Zollinger-Ellison syndrome.

Manifestations of esophageal disease are present in up to 60% of patients with Zollinger-Ellison syndrome (ZES), although esophageal function has been studied in only a few patients and the prevalence of Barrett's mucosa is unknown in these patients. It is unclear whether the high prevalence of esophageal disease is related to gastric acid hypersecretion alone or to abnormalities of esophageal motility or lower esophageal sphincter (LES) function in addition. To address these issues in the present study esophageal function was evaluated prospectively in 92 consecutive patients with ZES (66 with active disease, 26 disease-free after curative resection) seen during a 1-year period after controlling acid hypersecretion. In the patients with active disease the mean basal acid output (BAO) was 33 +/- 3.0 mEq/h, the maximal acid output (MAO) was 56 +/- 4.0 mEg/h, fasting serum gastrin was 8,736 +/- 4,813 pg/ml and duration of disease prior to study was 12.5 +/- 2.0 years. At the time of manometry, gastric acid secretion was controlled in all patients and no patient had evidence of gastroesophageal reflux disease at upper gastrointestinal endoscopy. Esophageal manometry revealed normal motility in 85% of patients. Eleven percent had low LES pressures, and only 1% of patients had an elevated LES pressure. The frequency of Barrett's mucosa (3%) was similar to that found in the general population but much less than that reported in patients with idiopathic GERD. No correlation was noted between LES pressures or manometric abnormalities and the fasting serum gastrin, BAO, MAO or the presence or absence of multiple endocrine neoplasia type I or previous vagotomy. Esophageal manometric results and LES pressure were similar in disease-free patients and those with active ZES. In conclusion, these results suggest that hypergastrinemia or other disease-specific abnormalities are not contributing to the high incidence of esophageal disease in patients with ZES because esophageal function in patients with ZES is similar to normals. Specifically, motility disorders in patients with ZES occur in similar frequency to normals, and LES pressure is normal in most patients. Despite the high levels of acid secretion and prominence of symptoms, the occurrence of Barrett's mucosa was uncommon (3%) raising the possibility of additional protective mechanisms in patients with ZES.

Adult↗
PubMed1992

Microvascular angina and the sensitive heart: historical perspective.

As our understanding of the etiology of chest pain of undetermined origin has evolved, the focus for studying this problem has switched from individual subspecialties to a multidisciplinary approach. In the subspecialties of gastroenterology and cardiology, the focus has shifted from organ-specific diagnoses to concepts of altered pain thresholds. Cardiologists began to look for functional causes of ischemia following the recognition that many patients with chest pain had normal coronary arteries. Abnormal responses of the coronary microcirculation to stress were identified in this population, and the concept of "microvascular angina" originated. Further evaluation, however, demonstrated that many of these patients did not have evidence of ischemia. In addition, a significant overlap with esophageal motility disorders was shown, and multiple sensitivities to otherwise nonirritating stimuli, whether in the heart or the esophagus, could be elicited in these patients. This finding led to the concept of abnormal visceral nociception, that is, the "sensitive heart" and the "tender esophagus," both the focus of ongoing clinical research.

Angina Pectoris↗