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Biomedical subjects

R A Hinder

Publications and source records attributed to R A Hinder.

At least 91 records · Page 5Linked to original sources
PubMed1995

Laparoscopic Nissen fundoplication.

Most patients with gastroesophageal reflux disease (GERD) can be treated effectively with medical therapy; however, in patients with severe GERD who are unresponsive to medical therapy, the lower esophageal sphincter (LES) is often found to be mechanically incompetent. Surgical therapy, which improves the LES antireflux barrier, may then be a good option. A very effective and popular antireflux procedure is the Nissen fundoplication, which can be safely done via the laparoscopic route. Preoperative evaluation should include contrast radiography, esophagoduodenoscopy (EGD) with biopsies, esophageal manometry, and 24-hour pH monitoring. Indications for surgery include failure or inability to continue on medical therapy, GERD-related respiratory symptoms, and severe complications of GERD, such as ulceration, stricture, and Barrett's esophagus. A short, loose Nissen fundoplication is ideal for patients with normal esophageal body motility. Operative complications are infrequent, and they include gastric perforation, bleeding, and pneumothorax. Following the laparoscopic approach, nearly all patients can leave the hospital on the first or second postoperative day. Follow-up esophageal manometry and 24-hour pH monitoring show the same good long-term results as seen after open Nissen fundoplication. Laparoscopic Nissen fundoplication can be performed safely and effectively with all of the advantages of a minimally invasive approach.

Esophagus↗
PubMed1994

Is Barrett's metaplasia the source of adenocarcinomas of the cardia?

OBJECTIVE: To investigate the prevalence of Barrett's esophagus in patients with adenocarcinomas located at the gastroesophageal junction. DESIGN: A case series of patients who underwent esophagogastrectomy for adenocarcinoma was retrospectively reviewed. Tumors were grouped by location as esophageal, cardiac, and subcardiac, and the prevalence of specialized intestinal metaplasia in the histological specimens was determined. SETTING: A university department of surgery that specializes in esophageal diseases. PATIENTS: One hundred patients with adenocarcinoma of the esophagus, cardia, or proximal stomach. MAIN OUTCOME: Cardiac adenocarcinomas were associated with Barrett's esophagus in 42% of the patients. RESULTS: Specialized intestinal metaplasia was identified in the histological sections from the resected specimen in 42% (13/31) of cardiac adenocarcinomas and in 79% (38/48) of esophageal adenocarcinomas but in only 5% (1/21) of subcardiac adenocarcinomas. The preoperative endoscopic biopsy results concurred with the final diagnosis of Barrett's esophagus in 33 of the 38 esophageal tumors, six of the 13 cardiac tumors, and the one subcardiac tumor but failed to detect specialized intestinal metaplasia in 54% (7/13) of cardiac tumors. Cardiac tumors were associated with shorter lengths of Barrett's mucosa than esophageal tumors (2.7 +/- 1.8 cm vs 7.4 +/- 3.4 cm, P < .01). The Barrett's metaplasia was dysplastic in 36 of the 38 esophageal tumors, 10 of the 13 cardiac tumors, but not in the subcardiac tumor. CONCLUSIONS: Adenocarcinomas located at the gastroesophageal junction were associated with Barrett's metaplasia in nearly one half of the patients. The length of the Barrett segment tends to be short and may be missed during endoscopy. The presence of high-grade dysplasia within Barrett's mucosa supports a barrett's origin for half of the adenocarcinomas arising at this location.

Adenocarcinoma↗
PubMed1994

Gastric remnant cancer has a better prognosis than primary gastric cancer.

OBJECTIVE: To study the prognosis of gastric remnant cancer following radical resection (group 1) compared with that of primary gastric cancer of the upper third of the stomach following radical resection (group 2). DESIGN: Cohort study with a 5-year follow-up. SETTING: A university hospital in Austria. PATIENTS: Group 1 consisted of 43 patients, and group 2, of 61. Postoperative deaths and deaths during the follow-up period that were not related to gastric cancer were excluded. Fifteen patients in group 1 (34.9%) presented with stage I cancer; 10 (23.3%), stage II; 13 (30.2%), stage III; and five (11.6%), stage IV. Twenty patients in group 2 (32.8%) presented with stage I cancer; 12 (19.7%), stage II; 15 (24.6%), stage III; and 14 (22.9%), stage IV (Union Internationale Contre le Cancer staging classification, 1987). MAIN OUTCOME MEASURES: Overall and stage-related 5-year survival rates. RESULTS: The overall 5-year survival rate was 53.5% in group 1 and 32.8% in group 2 (P < .05). The stage-related 5-year survival rate in group 1 was 100% for stage I and 80% for stage II. In group 2, the stage-related 5-year survival rate was 65% for stage I and 25% for stage II (both, P < .01). No significant difference was noted for stages III and IV. CONCLUSIONS: The prognosis of cancer of the gastric remnant presenting as stage I or II is good and is significantly better than that of the equivalent stages of primary cancer of the upper third of the stomach.

Adolescent↗
PubMed1994

Thoracoscopic esophageal myotomy--a surgical technique for achalasia diffuse esophageal spasm and "nutcracker esophagus".

Thoracoscopic myotomy has been performed for diffuse esophageal spasm "nutcracker esophagus" and achalasia. Technical considerations for thoracoscopic long myotomy such as trocar placement, length of myotomy, extent of myotomy distal to the gastroesophageal junction, hiatal closure, fundoplication and degree of esophageal mobilization are discussed.

Esophageal Achalasia↗
PubMed1994

Effect of gastroduodenal juice and dietary fat on the development of Barrett's esophagus and esophageal neoplasia: an experimental rat model.

BACKGROUND: Reflux of duodenal content into the lower esophagus of rats enhances the formation of nitrosamine-induced esophageal cancer and results in the induction of adenocarcinoma. We investigated the extent of the mucosal injury that was produced when the lower esophagus of rats was exposed to the reflux of gastroduodenal juice in the presence or absence of a carcinogen and tested the hypothesis that induction of esophageal cancer in this model would be influenced by the intake of dietary fat. METHODS: Esophagoduodenostomy with gastric preservation was performed in 165 Sprague-Dawley rats in order to expose the lower esophagus to the reflux of gastroduodenal juice. Postoperatively selected groups of rats were treated with the carcinogen methyl-n-amylnitrosamine (MNAN). Subsequently, rats were fed diets of differing fat and calorie content for 20 weeks until they were put to death. RESULTS: Refluxed gastroduodenal juice, in the absence of MNAN, induced esophageal inflammatory changes (diffuse papillomatosis and hyperkeratosis) in 38 of 39 rats (97%), specialized columnar metaplasia (Barrett's esophagus) in four of 39 (10%), dysplasia in three of 39 (8%), and squamous cell carcinoma in one of 39 (3%). Diet did not influence the incidence of neoplasia in the absence of MNAN treatment. In rats treated with MNAN, refluxed gastroduodenal juice induced inflammation in 110 of 111 rats (99%), columnar metaplasia in 14 of 111 (13%), and cancer in 63 of 111 (57%). Fifty-eight percent of esophageal tumors were squamous cell carcinoma and 42% were adenocarcinoma. The highest incidence of tumors was observed in rats fed the semipurified high-fat diet (24 of 29; 83%) compared with rats fed the semipurified control diet (13 of 29; 45%), semipurified, calorie-restricted diet (15 of 27; 55%), and chow diet (11 of 26; 42%), p < 0.05. CONCLUSIONS: Reflux of gastroduodenal content into the lower esophagus of rats can induce both Barrett's metaplasia and neoplasia. Addition of a carcinogen increases the tumor yield and results in a proportion of the lesions being adenocarcinoma. This carcinogenic process is promoted by a diet with a high fat content.

Adenocarcinoma↗
PubMed1994

Gastroesophageal reflux disease is associated with enteric hormone abnormalities.

Basal and postprandial levels of the foregut hormones gastrin, cholecystokinin (CCK), motilin, and pancreatic polypeptide, and the distal gut hormones neurotensin and peptide YY were measured in 20 patients with gastroesophageal reflux disease (GERD). GERD was defined by abnormal esophageal exposure to pH less than 4. Ten GERD patients had decreased lower esophageal sphincter (LES) pressure (mean: 4.5 mm Hg, range: 0.8 to 6.8 mm Hg), and 10 patients had normal LES pressures (mean: 14.1 mm Hg, range: 9.7 to 22.4 mm Hg). Eight age-matched healthy subjects were also studied. Basal levels of peptide YY were moderately decreased in GERD patients compared with controls irrespective of LES pressure. In patients with abnormal LES pressure, basal levels of motilin and the postprandial response of CCK were significantly decreased compared with controls; and basal levels of neurotensin and the postprandial response of gastrin were significantly increased compared with controls. Pancreatic polypeptide levels were similar in all groups. These gut hormone changes, which are more marked in patients with poor LES pressure, may reflect primary or secondary abnormalities in GERD.

Esophagogastric Junction↗
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

Interposition of 'narrow' cycloperistaltic segments into isolated segments of jejunum--influence on fluid perfusion.

Two isolated segments of jejunum with the ends exteriorised as jejunostomies were created in each of 8 dogs. Towards the end of one of the two, a cycloperistaltic (C-P) segment, with a diameter 70% of that of the jejunum, was interposed. Fluid containing C-labelled polyethylene glycole [corrected] was infused at 4 ml/min through each of the 16 preparations and the results were compared. The presence of a C-P segment significantly reduced the volume of output (with C-P segment--mean (+/- standard deviation) 155.27 +/- 14.81 ml/h v. without C-P segment--210.09 +/- 19.41 ml/h) (P < 0.001) and increased absorption (with C-P--45.44 +/- 20.86 ml/h v. without C-P--20.48 +/- 8.42 ml/h) (P < 0.001) and pooling (with C-P--39.29 +/- 16.99 ml/h v. without C-P--9.42 +/- 17.16 ml/h) (P < 0.001). The C-P segment therefore delayed the passage of the perfused fluid.

Anastomosis, Surgical↗
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

Prolonged ambulatory antroduodenal manometry in humans.

OBJECTIVES: To perform prolonged ambulatory recordings of antroduodenal motor activity in humans. METHODS: Antroduodenal manometric recordings were performed in 20 normal subjects (12 male, eight female, ages 19-41 years), using a 5-channel solid state catheter assembly (three antral, two duodenal transducers) positioned under fluoroscopy. A glass electrode simultaneously recorded pH in the antrum. RESULTS: Continuous, simultaneous recordings of antral and duodenal motor activity were obtained for 22.5 +/- 0.3 h. During fasting, 131 complete migrating motor complexes (MMCs) were recorded (6.6 +/- 0.9/subject). The average interval from onset of recording to completion of the first MMC cycle was 498 +/- 19.24 minutes. Significant diurnal variations were observed in MMC frequency (awake vs asleep: 0.25/subject/h vs 0.64/subject/h; p < 0.05), period (shorter during sleep), phase I duration (longer during sleep), and phase II duration (shorter during sleep). Among females, MMCs were more frequent and shorter. After meal administration, duodenal recording sites demonstrated a typical "fed" response; antral distension and/or retrograde catheter movement, on meal ingestion, however, precluded reliable antral "fed" recordings. CONCLUSIONS: Prolonged ambulatory antroduodenal manometry provides detailed and reliable information on fasting antral and duodenal motor activity, antral distension, and/or retrograde catheter migration on meal ingestion; there are limits, however, to the usefulness of this methodology for the evaluation of the fed motor response in the antrum.

Adult↗
PubMed1993

Effect of verapamil on hepatic ischemia/reperfusion injury.

Alterations in cellular calcium homeostasis are a critical factor in the pathogenesis of hepatic ischemic damage and may mediate oxygen free radical injury during the reperfusion period. We investigated the effect of the calcium channel blocker verapamil on hepatic ischemia/reperfusion injury in normal rats and rats sensitized to oxidative injury by chemical depletion of the endogenous antioxidant glutathione. Forty-five minutes of complete hepatic ischemia followed by reperfusion caused an increase in the serum glutamic pyruvic transaminase (SGPT) level and a decline in the endogenous hepatic glutathione level but no increase in hepatic lipid peroxidation products. Chemical depletion of hepatic glutathione with diethylmaleate did not induce hepatocellular injury but augmented hepatic ischemia/reperfusion-induced SGPT release and promoted lipid peroxidation. Pretreatment with the calcium entry blocker verapamil protected against the ischemia/reperfusion-induced drop in hepatic glutathione but did not reduce SGPT release in normal rats. In rats sensitized to oxidative injury by chemical depletion of endogenous glutathione, the calcium channel blocker verapamil protected against ischemia/reperfusion-induced lipid peroxidation and reduced the release of SGPT. These findings indicate that the rat liver is protected against oxidative injury after short periods of total ischemia by its rich supply of endogenous glutathione. A beneficial effect of verapamil occurs only in rats sensitized to oxidative injury, suggesting that the calcium channel blocker protects against oxygen radical attack.

Alanine Transaminase↗
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

Comparison of an intravenous bolus of famotidine and Mylanta II for the control of gastric pH in critically ill patients.

The effects of the intravenous bolus administration of famotidine versus the administration of Mylanta II liquid every 2 hours on the pH of the gastric antrum, body, and fundus for 24 hours were compared in 10 critically ill patients admitted to the intensive care unit with isolated cranial trauma. Patients received 30 mL of Mylanta II every 2 hours via nasogastric tube for 24 hours, followed by administration of 20 mg of intravenous bolus famotidine every 12 hours for the subsequent 24-hour period. pH of the gastric antrum, body, and fundus was monitored continuously using a three antimony pH electrode/nasogastric tube assembly. Gastric pH data were analyzed for the percentage of time pH was less than 4 and median pH for the antrum, body, and fundus for each 24-hour period. The percentage of time pH was less than 4 was significantly less in the antrum and body of the stomach during famotidine therapy (8.9% +/- 3.6% and 24.9% +/- 6.9%, respectively) compared with Mylanta II (39.1% +/- 6.7% and 57.6% +/- 8.5%, respectively, both p < 0.005), but was not significantly different in the fundus (famotidine: 25.3% +/- 7.8%; Mylanta II: 28.3% +/- 6.5%). Median gastric pH for 24 hours was significantly greater in the antrum and body of the stomach during famotidine therapy (7.8 +/- 0.2 and 6.8 +/- 0.6, respectively) compared with Mylanta II (4.5 +/- 0.6 and 3.7 +/- 0.9, respectively, p < 0.005 and p < 0.01, respectively), but was not significantly different in the fundus (famotidine: 5.9 +/- 0.8; Mylanta II: 5.4 +/- 0.7). The data indicate that an intravenous bolus of famotidine every 12 hours is more effective than Mylanta II liquid every 2 hours administered via a nasogastric tube in maintaining gastric pH above 4 in critically ill patients. Famotidine produces a uniform increase in gastric pH throughout the stomach, whereas Mylanta II controls only proximal gastric pH, probably related to fundic pooling of antacid in the supine position.

Adult↗
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

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↗