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Biomedical subjects

T R DeMeester

Publications and source records attributed to T R DeMeester.

At least 127 records · Page 7Linked to original sources
PubMed1994

Laparoscopic Nissen fundoplication is an effective treatment for gastroesophageal reflux disease.

OBJECTIVE: The open Nissen fundoplication is effective therapy for gastroesophageal reflux disease. In this study, the outcomes in 198 patients treated with the laparoscopic Nissen fundoplication was evaluated for up to 32 months after surgery to ascertain whether similar positive results could be obtained. SUMMARY BACKGROUND DATA: To ensure surgical success, patients were required to have mechanically defective sphincters on manometry and increased esophageal acid exposure on 24-hour pH monitoring. The patients either had severe complications of gastroesophageal reflux disease or had failed medical therapy. These requirements have been found to be necessary to ensure a successful surgical outcome. METHODS: The disease was complicated by ulceration (46), stricture (25) and Barrett's esophagus (33). Patients underwent standard Nissen fundoplications identical in every detail to open procedures except that the procedures were carried out by the laparoscopic route. RESULTS: Perioperative complications included gastric or esophageal perforation (3), pneumothorax (2), bleeding (2), breakdown of crural repair (2) and periesophageal abscess (1). The only mortality occurred from a duodenal perforation. Six patients required conversion to the open procedure. The median hospital stay was 3 days. One hundred patients were observed for follow-up for 6 to 32 months (median 12 months), with outcomes similar to the open Nissen fundoplication. Further surgery was required for two patients who had recurrent gastroesophageal reflux and one who developed an esophageal stricture. Ninety-seven percent are satisfied with their decision to have the operation. CONCLUSIONS: The laparoscopic Nissen fundoplication can be carried out safely and effectively with similar positive results to the open procedure and with all of the advantages of the minimally invasive approach.

Anesthesia, General↗
PubMed1994

Technique, indications, and clinical use of ambulatory 24-hour gastric pH monitoring in a surgical practice.

BACKGROUND: Prolonged pH monitoring is used increasingly to assess alterations of gastric luminal pH caused by gastroduodenal secretory and motor abnormalities. The clinical value of gastric pH monitoring, however, has been debated. METHODS: We obtained normal values for 24-hour ambulatory gastric pH monitoring in 50 healthy volunteers and evaluated its clinical use by monitoring pH in 285 consecutive patients with nonspecific foregut symptoms and duodenal ulcers (n = 33), gastric ulcers (n = 21), antral gastritis (n = 123), or no mucosal injury (n = 108). RESULTS: Patients with duodenal ulcer had a shift of their recorded pH values to a more acidic range, particularly during the night (p < 0.01). Multiple regression analysis showed that an increased percentage of time pH was less than 1.2 during the night indicates gastric acid hypersecretion. In contrast, patients with gastric ulcer or antral gastritis had an increased frequency of alkaline peaks and percentage of time spent at a pH greater than 3 (p < 0.01). The presence of excessive duodenogastric reflux was identified in 39% of these patients as compared with 7% with no gastric mucosal injury (p < 0.01). Delayed gastric emptying was suggested by prolonged postprandial alkalinization of the gastric pH record in 25% of the patients. Radionuclide gastric emptying studies confirmed this in 85% of these patients. CONCLUSIONS: Gastric pH monitoring allows evaluation of gastric secretory state fluctuation in gastric pH environment, duodenogastric reflux, and gastric emptying under physiologic conditions during a complete circadian cycle and has potential to be one of the most inclusive initial tests of gastroduodenal function.

Adolescent↗
PubMed1994

Twenty-four-hour gastric luminal pH in normal subjects: influence of probe position, food, posture, and duodenogastric reflux.

OBJECTIVES: The aim of this study was to determine the gastric pH at different levels in the stomach under varying physiological circumstances. METHODS: Simultaneous 24-hour ambulatory gastric pH monitoring was performed with multiple electrodes in 24 normal subjects, divided into groups of six, to study the influence of food, the supine posture, and physiological duodenogastric reflux on gastric pH in different parts of the stomach. In 18 subjects, simultaneous recordings were made from two electrodes positioned 5 and/or 10 cm below the manometrically-defined lower border of the lower esophageal sphincter and, in six subjects, from three electrodes, one positioned 5 cm below the lower esophageal sphincter and two others positioned 5 and 8 cm proximal to the pylorus. RESULTS: During the daytime fasting period, pH was homogenous across the stomach with most time being spent between pH 1 and 2. Marked similarities in recorded pH were noted when two probes were placed in the stomach at the same level, indicating regional consistency in the pH of the chyme. This finding was observed when probes were free from each other or tethered together. Food increased pH most in the fundus, less in the midstomach, and least in the antrum. At night, when supine, alkaline shifts occurred in the distal stomach, most likely because of physiological duodenogastric reflux. These were commonly recorded in the antrum but only occasionally in the proximal stomach. CONCLUSIONS: Measurement of the gastric pH environment requires standardization of the probe position, of feeding, and of posture, and global measurement of gastric pH requires simultaneous recording in both the proximal and distal stomach.

Adult↗
PubMed1994

Outcome of adenocarcinoma arising in Barrett's esophagus in endoscopically surveyed and nonsurveyed patients.

The value of endoscopic surveillance of Barrett's esophagus and the appropriate management of high-grade dysplasia remain unclear. Seventeen patients who were referred from endoscopic surveillance programs for management of high-grade dysplasia or adenocarcinoma developing in Barrett's esophagus were compared with 35 patients who had a newly recognized Barrett's adenocarcinoma, who had not been in a surveillance program. The referral diagnosis in the surveyed group was adenocarcinoma in six and high-grade dysplasia in 11. After repeat endoscopy with aggressive biopsy, two additional patients with adenocarcinoma were identified. Of the nine patients who underwent esophagectomy for high-grade dysplasia, five had invasive adenocarcinoma in the esophagectomy specimen, which had been missed before the operation, despite the fact that the median number of biopsy specimens obtained per 2 cm of Barrett's mucosa was 7.8 (range 1.5 to 15.0). Overall, 13 patients in the surveyed group had adenocarcinoma, 12 staged early and one staged intermediate by the WNM classification. Surveyed patients were operated on at an earlier stage than the nonsurveyed patients (10 early, 14 intermediate, and 11 late stage tumors; chi 2 = 15.6, p < 0.01). Despite the presence of adenocarcinoma in 13 of the 17 surveyed patients, their survival was significantly better than that of the nonsurveyed group (chi 2 = 5.8, p < 0.05). Patients referred from surveillance programs for Barrett's esophagus have a better outcome and earlier stage tumors than nonsurveyed patients. Inasmuch as multiple biopsy procedures do not exclude the presence of adenocarcinoma, continued surveillance of high-grade dysplasia is dangerous and potentially destructive to surveillance efforts.

Adenocarcinoma↗
PubMed1994

The effect of symptoms and nonspecific motility abnormalities on outcomes of surgical therapy for gastroesophageal reflux disease.

The outcome of Nissen fundoplication in patients with a nonspecific motility abnormality compared with the outcome in patients with normal motility is unknown. One hundred consecutive patients who underwent primary Nissen fundoplication were evaluated before and a median of 50 months after operation, with emphasis on the presence of a preoperative motility disorder and its relationship to preoperative and postoperative symptoms. Compared with patients who had normal motility, patients with a nonspecific motility abnormality had a greater prevalence and severity of heartburn and regurgitation before operation. These patients also had a greater esophageal exposure to gastric juice on pH monitoring as a result of poorer esophageal clearance function. The prevalence and severity of preoperative dysphagia was not related to the presence of a motility disorder. A 90% or a 95% actuarial success rate was achieved in the relief of heartburn and regurgitation over a 96-month period in patients with and without a motility abnormality. The overall actuarial success rate was 93%. Dysphagia was rarely caused or made more severe by the procedure; if present before the operation, it was relieved in most patients. The prevalence of persistent postoperative dysphagia was similar in patients with and without a motility abnormality. The success of Nissen fundoplication in properly selected patients is not affected by the presence of a nonspecific motility disorder.

Deglutition Disorders↗
PubMed1993

Manometry of individual segments of the distal esophageal sphincter. Its relation to functional incompetence.

The major components of the lower esophageal sphincter, the pressure it exerts, its total length, and the length of sphincter affected by abdominal pressure are usually expressed as means of several recordings from different radial segments of the sphincter. In segmental manometry, the individual readings for these components in each segment, rather than the mean values, are analyzed. We used segmental manometry to study 50 normal volunteers and 200 patients with symptoms suggestive of gastroesophageal reflux. Of the latter, 100 had increased esophageal acid exposure and 100 did not. An increased number of defective segments was associated with a greater prevalence of increased esophageal acid exposure. Segmental analysis disclosed the same number (52) of defective sphincters (defined as sphincters with two or more defective segments) in the 100 patients with increased acid exposure as did standard analysis. However, the relationship between a defective lower esophageal sphincter and the number of reflux episodes was clearer when a defective sphincter was defined using standard analysis. Segmental analysis of the lower esophageal sphincter has no clear advantage over standard analysis.

Adolescent↗
PubMed1993

Abnormal plasma gut hormones in pathologic duodenogastric reflux and their response to surgery.

Fasting and postprandial plasma levels of the gut hormones gastrin, cholecystokinin (CCK), secretin, glucose-dependent insulinotropic polypeptide, motilin, neurotensin, peptide YY (PYY), enteroglucagon, glucagon, insulin, and pancreatic polypeptide were measured in 11 patients with alkaline gastritis associated with excessive duodenogastric reflux not related to previous gastric surgery (primary DGR), 12 primary DGR patients after pancreatico-biliary diversion ("duodenal switch" procedure), and in 10 age-matched healthy controls. Gastric emptying of a semisolid oatmeal was also measured in patients with primary DGR and in patients after bile diversion. Fasting plasma levels of the distal gut hormone neurotensin and the pancreatic islet hormone insulin were significantly greater in patients with primary DGR compared with controls. Neurotensin levels were normal in patients studied after bile diversion. Postprandial plasma levels, incremental integrated and total integrated responses for CCK, secretin, insulin, neurotensin, PYY, and enteroglucagon, were significantly greater in patients with primary DGR compared with controls. The majority of these responses normalized after bile diversion; however, the postprandial response for insulin and enteroglucagon remained elevated. Patients with primary DGR had a rapid early postprandial phase of gastric emptying of solids, which showed a significant correlation with plasma neurotensin levels. Bile diversion produced a significant delay in this lag-phase of gastric emptying. These abnormalities in gut regulatory hormones appear to be adaptive changes to rapid early postprandial gastric emptying, probably related to antropyloric dysmotility, which has been implicated in the pathogenesis of this condition. Measurement of these gastrointestinal hormones may become useful in the diagnosis of primary DGR.

Anastomosis, Roux-en-Y↗
PubMed1993

Outcome effect of adherence to operative principles of Nissen fundoplication by multiple surgeons. The Department of Veterans Affairs Gastroesophageal Reflux Disease Study Group.

Fifty-eight patients participated in a multi-institutional study designed to assess the outcome of Nissen fundoplication when performed for complicated disease by a variety of surgeons with varied skill and experience with compliance to established technical principles. All patients had an abnormal 24-hour pH study and mucosal injury on endoscopy. The surgical procedures were performed in 8 Veterans Administration hospitals by surgical residents supervised by surgical faculty, after initial agreement on 10 operative principles for the Nissen fundoplication. The mean symptomatic scores at 52 and 104 weeks improved significantly compared with the preoperative score (p < 0.0001). There was significant improvement in total percent time at pH below 4 at 52 weeks (p < 0.01) and 104 weeks (p < 0.01). There was significant improvement in the grade of esophagitis at 1 year (p < 0.0001). Compliance was greater than 90% for 7 of 10 principles of repair. In conclusion, a Nissen fundoplication resulted in relief of symptoms in 93% of patients and a 77% rate of healing of esophagitis. These results in complicated reflux disease were achieved by a variety of surgeons with varied experience in antireflux surgery.

Esophagitis↗
PubMed1993

Gastroesophageal reflux.

Gastroesophageal reflux is a common disease that accounts for approximately 75% of esophageal pathology. Motility abnormalities of the esophagus and stomach, including an incompetent lower esophageal sphincter, are responsible for pathologic reflux in the majority of patients. Surgical treatment offers the only chance for long-term cure. Obtaining optimal results following surgery of the esophagus is one of the most challenging aspects of modern surgical therapy. Given a precise diagnosis, careful patient selection, critical attention to detail in the perioperative period, and the meticulous performance of the appropriate anti-reflux procedure, long-term success can be assured in more than 90% of patients.

Gastroesophageal Reflux↗
PubMed1993

Metabolism of carcinogenic nitrosamines in the rat and human esophagus and induction of esophageal adenocarcinoma in rats.

The mechanism is discussed by which certain nitrosamines induce esophageal papillomas and squamous cancer in rats, and some evidence is presented for the view that nitrosamines also induce the same cancer in humans, especially in China and South Africa. Studies on the metabolism of nitrosamines by cytochrome P450 isozymes in rat and human esophagus, including the activation reactions of formaldehyde and pentaldehyde formation from methyl-n-amylnitrosamine (MNAN), are reviewed. These reactions are catalyzed by microsomes from the rat and human esophagus, probably because these microsomes contain specific cytochrome P450 isozymes. Evidence is reviewed for the occurrence of nitrosamines related to MNAN in fungus-infected corn. The incidence of esophageal adenocarcinoma is rising in Western countries. The precursor lesion, Barrett's esophagus, is associated with colon cancer, suggesting a role for bile salts in the induction of the esophageal tumor. Studies are described in which rats were subjected to esophago-duodenostomy (joining the duodenum to the esophagus) and then treated with nitrosamines that normally induce esophageal squamous cancer. Adenocarcinomas of the lower esophagus were induced as well as Barrett's esophagus (under one set of conditions). Feeding a high-fat diet with this system increased the incidence of esophageal adenocarcinoma. This tumor was not induced when the operation was changed to esophago-gastroplasty (widening the lower esophageal sphincter). These results support a role of reflux of duodenal contents (including bile and pancreatic juice) rather than of gastric contents in the etiology of human esophageal adenocarcinoma.

Adenocarcinoma↗
PubMed1993

Indications, technique, and clinical use of ambulatory 24-hour esophageal motility monitoring in a surgical practice.

The development of miniaturized electronic pressure transducers and portable digital data recorders with large storage capacity has made ambulatory monitoring of esophageal motor function over an entire circadian cycle possible. The broad clinical application of this new technology in a large number of asymptomatic normal volunteers and patients with primary esophageal motor disorders or gastroesophageal reflux disease provides new insights into esophageal motor function in health and disease under a variety of physiologic conditions. In normal volunteers and symptomatic patients, esophageal motor activity increases with both the state of consciousness and eating activity, i.e., from sleep to awake to meal periods. In the normal situation there is a higher prevalence of nonperistaltic esophageal contractions than appreciated on stationary manometry. Compared with standard manometry, ambulatory esophageal manometry provides a more than 100-fold larger database for the classification and quantitation of abnormal esophageal motor function and leads to a change in the diagnosis in a substantial portion of patients with symptoms suggestive of a primary esophageal motor disorder. In patients with nonobstructive dysphagia, the circadian esophageal motility pattern is characterized by an inability to organize the motor activity into peristaltic contractions during meal periods. In patients with noncardiac chest pain, ambulatory motility monitoring can document a direct correlation of abnormal esophageal motor activity with the symptom and shows that the abnormal motor activity immediately preceding the pain episodes is characterized by an increased frequency of simultaneous, double- and triple-peaked, high-amplitude, and long-duration contractions. A long esophageal myotomy can abolish the ability of the esophagus to produce this abnormal motor pattern. In patients with gastroesophageal reflux disease, ambulatory motility monitoring shows that the contractility of the esophageal body deteriorates with increasing severity of esophageal mucosal injury, compromising the clearance function of the esophageal body. These data suggest that ambulatory esophageal motility monitoring allows for a more precise classification of esophageal motor disorders than standard manometry and can identify abnormal esophageal motor pattern associated with nonobstructive dysphagia, noncardiac chest pain, or gastroesophageal reflux. Ambulatory esophageal manometry therefore should replace standard manometry in the assessment of esophageal body function and has potential to improve the diagnosis and management of patients with esophageal motor abnormalities. The combination of ambulatory 24-hour esophageal manometry with esophageal and gastric pH monitoring is currently the most physiologic way to assess patients with functional foregut disorders.

Chest Pain↗
PubMed1993

Pharyngeal swallowing. The major factor in clearance of esophageal reflux episodes.

OBJECTIVE: This study defined the clearance mechanisms of naturally occurring reflux episodes in normal subjects and patients with gastroesophageal reflux disease. SUMMARY BACKGROUND: Previous studies on acid clearance have been performed in the laboratory setting in supine subjects using acid instillation and stationary motility. The mechanisms of clearance have not been studied using ambulatory pH and motility monitoring. METHODS: A new system capable of monitoring simultaneously for 24 hours pharyngeal pressure, esophageal motility, and pH was used to study the clearance of naturally occurring reflux episodes in 10 normal subjects and 18 patients with gastroesophageal reflux disease. Esophageal contraction waves were classified as primary (i.e., initiated by a pharyngeal swallow) and secondary (i.e., unrelated to a pharyngeal swallow). RESULTS: A total of 1288 reflux episodes were analyzed, during which 2781 contraction waves occurred. Clearance (i.e., restoration of pH to > 4) occurred after primary peristalsis in 83% of reflux episodes. An additional 11% were cleared by pharyngeal swallows without an esophageal body response. Secondary waves were rare and when they occurred, only 19% were peristaltic. Secondary peristalsis cleared only 9 of the 1288 reflux episodes. Patients and normal subjects cleared reflux episodes similarly. Baseline swallowing frequency was 0.87/min during the daytime and increased to 2.59/min (p < 0.01) during daytime reflux episodes. Swallowing frequency in response to nighttime reflux episodes was less (1.42/min; p < 0.05). CONCLUSIONS: Pharyngeal swallowing is the most important mechanism for esophageal acid clearance. Secondary waves are rare, usually disorganized, and unimportant in clearing a reflux episode. During sleep, the mechanisms of clearance are depressed.

Adolescent↗
PubMed1993

Cervical dysphagia is associated with gastric hyperacidity.

There is some controversy regarding the association of upper esophageal symptoms and acid gastroesophageal reflux. We carried out gastric acid analysis, 24-h esophageal pH measurement, and esophageal manometry in 150 patients with symptoms suggestive of gastroesophageal reflux disease. Of these, 22 (15%) had gastric acid hypersecretion [basal acid output level > 5 mmol/h (19 patients) or maximum acid output level > 30 mmol/h (13 patients)]. They were compared to 25 consecutive patients with normal gastric acid secretion. An incompetent lower esophageal sphincter was identified in a similar number of hypersecretors (HS) (59.1%) and normosecretors (NS) (44%). Esophageal acid exposure was more common in HS than in NS (score, 70 vs. 36.1, p < 0.05). This was reflected as a higher incidence of esophagitis in HS (67 vs. 14%, p < 0.0025). Symptoms of cervical dysphagia were present in eight of 22 HS and one of 25 NS (p = 0.009). There was no anatomical lesion on endoscopy to explain the dysphagia. Upper esophageal sphincter (UES) manometry showed normal pharyngeal pressure, resting UES pressure, and length in both groups. The mean closing UES pressure was 127 mm Hg in HS and 114 mm Hg in NS (0.1 > p > 0.05). The HS with cervical dysphagia were no different from HS without dysphagia in any respect. We conclude that patients with gastric acid hypersecretion have more acid reflux, esophagitis, and cervical dysphagia. This is not associated with demonstrable abnormality in stationary manometry. Prolonged measurement may be required to show any change.

Adult↗
PubMed1993

Value of physiologic assessment of foregut symptoms in a surgical practice.

BACKGROUND: The aim of this study was to evaluate the reliability of symptoms in the diagnosis of gastroesophageal reflux disease and esophageal motility disorders as assessed by functional tests. METHODS: In 365 patients referred for suspected esophageal functional disease, symptomatic assessment was compared with the results of esophageal manometry and ambulatory 24-hour pH monitoring of the distal esophagus. RESULTS: Based on the patients' chief complaint, the symptomatic diagnosis was gastroesophageal reflux (44%), esophageal motor disorder (26%), chest pain of esophageal origin (9%), reflux and aspiration (8%), and abdominal pathology (12%). The symptomatic diagnosis was considerably altered by the results of the esophageal function tests: gastroesophageal reflux and motility disorders were found in all symptomatic diagnostic groups and a large number of patients in each group tested normal. The sensitivity and specificity of symptom-based diagnoses for functional disease were low. CONCLUSIONS: The results of this study showed that symptoms are an unreliable guide of esophageal abnormality, illustrating the need for objective testing in these patients, particularly to avoid inappropriate medical or surgical therapy.

Adolescent↗
PubMed1993

Superiority of extended en bloc esophagogastrectomy for carcinoma of the lower esophagus and cardia.

The belief that transhiatal esophagogastrectomy results in the same survival as a more extensive en bloc resection was tested in 69 patients with carcinoma in the distal esophagus and gastric cardia. Preoperative and intraoperative staging defined three distinct subgroups of patients. Those with apparently limited disease and good general health (group I, n = 30) underwent en bloc resection. Those with apparently limited disease but poor physiologic reserve (group II, n = 16) underwent transhiatal resection, as did those with evidence of more advanced disease (group III, n = 23). Overall, survival was significantly better in the 30 patients who underwent en bloc resection (41%) than in the 39 patients who underwent transhiatal resections (14%; p < 0.001, log-rank). Clinical staging showed apparently limited disease in 46 patients (groups I and II). These groups differed only in the presence of poor physiologic reserve because the percentages of patients with tumors limited to the esophageal wall (group I 13/30, group II 6/16) and four or fewer lymph node metastases (group I 21/30, group II 15/16) at the time of pathologic staging were not significantly different. Survival after en bloc resection was, however, significantly better (41% versus 21%; p < 0.05, log-rank). According to the WNM system of pathologic staging, 19 patients had early lesions defined as intramural lesions associated with four or fewer lymph node metastases, 26 had intermediate lesions defined as either transmural or associated with more than four lymph node metastases, and 24 had late lesions defined as both transmural and associated with fewer than four lymph node metastases. Survival was significantly better in patients with early lesions after en bloc resection compared with transhiatal resection (75% versus 20%, p < 0.01), survival was also significantly better in patients with advanced lesions (27% versus 9%, p < 0.01). For intermediate lesions, the survival was similar (14% versus 20%), although the median survival after en bloc resection was longer (24 months versus 8 months).

Actuarial Analysis↗
PubMed1993

Functional foregut abnormalities in Barrett's esophagus.

The factors predisposing to the development of Barrett's esophagus in patients with gastroesophageal reflux disease are unclear. We compared symptoms, esophageal acid and alkaline exposure (pH < 2, < 3, < 4, and > 7), lower esophageal sphincter resistance, esophageal clearance function, the gastric secretory state, gastric emptying, and duodenogastric reflux in 15 patients with Barrett's esophagus with 24 patients with esophagitis and with 22 normal subjects. Compared with patients with esophagitis, patients with Barrett's esophagus had less heartburn and regurgitation but had an increased frequency and duration of reflux episodes and percent time pH less than 2, less than 3, less than 4, and pH greater than 7 on ambulatory 24-hour esophageal pH monitoring. This was associated with a decreased lower esophageal sphincter resistance, a decreased contraction amplitude in the distal area of the esophagus, an increased frequency of nonperistaltic contractions and contractions less than 30 mm Hg on 24-hour ambulatory esophageal motility monitoring, increased basal and stimulated gastric acid secretion, and a higher prevalence of excessive duodenogastric reflux. These data show that despite less symptoms patients with Barrett's esophagus have a markedly increased esophageal acid and alkaline exposure compared with patients with esophagitis. This appears to be because of persistent reflux of highly concentrated gastric acid and duodenal contents across a mechanically defective lower esophageal sphincter in combination with inefficient esophageal clearance function.

Barrett Esophagus↗