Does duodenal juice reflux into the esophagus of patients with complicated GERD? Evaluation of a fiberoptic sensor for bilirubin

BACKGROUND

It is controversial whether duodenal juice can damage esophageal mucosa in patients with gastroesophageal reflux disease (GERD). The issue remains unresolved partly because of difficulties in detecting the presence of duodenal juice in the lower esophagus.

OBJECTIVES AND METHODS

This study utilized an in vitro portable spectrophotometer with a fiberoptic probe capable of detecting bile as a marker of duodenal juice. Absorbance/concentration curves were established with known bilirubin concentrations at pH 1.4 and pH 7.7. Esophageal pH and bilirubin absorbance were monitored in vivo over a 24-hour period in 20 healthy volunteers to determine the absorbance threshold for clinical use. The study population consisted of 21 patients with GERD. Four had no mucosal injury, 5 erosive esophagitis, and 12 Barrett's esophagus.

RESULTS

The correlation between absorbance and bilirubin concentration was 0.98 and 0.99 for acid and alkaline environments, but bilirubin absorbance was 35% less in an acid environment. Using an absorbance threshold of 0.14, patients with GERD taken in toto had elevated esophageal exposure to bilirubin. No difference was observed in bilirubin exposure between reflux patients without mucosal injury and controls. Highest exposure occurred in patients with Barrett's esophagus. An important observation was that esophageal bilirubin exposure frequently occurred during periods when the esophageal pH was in the normal range.

CONCLUSIONS

The fiberoptic probe accurately detects esophageal bilirubin as a marker of duodenal juice. Esophageal exposure to bilirubin is uncommon in normal subjects. Patients with erosive esophagitis and Barrett's metaplasia have increased esophageal exposure to duodenal juice compared to normal subjects. Reflux of duodenal juice into the esophagus can occur when the esophageal pH is within its normal range and is undetectable by pH monitoring alone.

Motility in the Hunt-Lawrence pouch after total gastrectomy

PURPOSE

The aim of this study was to evaluate motility patterns of the Hunt-Lawrence pouch and the jejunal limb of patients reconstructed with a pouch after total gastrectomy, and to compare the findings in symptomatic patients to those without symptoms after the operation.

PATIENTS AND METHODS

Thirty-three patients who had undergone post-gastrectomy pouch reconstruction were studied using a water-perfused motility system. In 21, the pouch was connected by a Roux-en-Y, and, in 12, by a jejunal interposition. Twenty-eight patients were asymptomatic, including 17 connected by a Roux-en-Y and 11 by a jejunal interposition. Five patients were by a jejunal interposition. Five patients were symptomatic, including 4 connected by Roux-en-Y Y and 1 by jejunal interposition. A control group consisted of 5 healthy volunteers who had not undergone operation.

RESULTS

The motility phases in the pouch and jejunal limb of asymptomatic patients were of shorter duration than those of controls, and they followed a random sequence instead of a normal progression from phase I to II to III. Motility features were similar in the pouch and the jejunal limb. Orthograde propagation of phase III-like activity was reduced and may contribute to the pouch storage function. Four of the 5 symptomatic patients showed highly abnormal motility with hypomotile or obstructive patterns. The technique of connecting the pouch--jejunal interposition of Roux-en-Y--did not affect the motility findings.

CONCLUSIONS

The altered motility occurs after a Hunt-Lawrence pouch reconstruction in asymptomatic patients. Symptoms after gastrectomy are associated with further disturbed motility that can be differentiated from the motility changes in asymptomatic patients.

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.

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.

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.

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.

Nodal metastasis and sites of recurrence after en bloc esophagectomy for adenocarcinoma

The operative specimens from 43 patients undergoing en bloc esophagectomy for adenocarcinoma of the lower esophagus or cardia were analyzed. Depth of invasion of the tumor and extent and location of lymph node metastases were determined. Postoperative recurrence was identified from positive findings on successive 3-month computed tomographic scans. Positive nodes occurred in 33% (2/6) of intramucosal tumors, 67% (6/9) of intramural tumors, and 89% (25/28) of transmural tumors (p < 0.01). Commonly involved nodes were those in the lesser curve of the stomach (42%), parahiatal nodes (35%), paraesophageal nodes (28%), and celiac nodes (21%). Excluding perioperative deaths, follow-up was complete for 38 patients. Twenty patients had recurrence. Fifteen patients (40%, 15/38) had nodal recurrence: cervical, 7.9% (3/38); superior mediastinal, 21% (8/38); and abdominal, 24% (9/38) (retropancreatic in 7 and retrocrural in 2). Of 5 patients with nodal recurrence alone, 3 (60%) had recurrence at sites outside the margins of resection. Patients with four metastatic nodes or less had a survival advantage over those with more than four (p < 0.05). There was no difference in survival according to location of nodal metastases. Two (22.2%) of 9 patients with celiac node metastases survived longer than 4 years. Adenocarcinoma of the lower esophagus and cardia spreads widely to mediastinal and abdominal nodes, and death can occur from nodal disease. Rates of lymph node metastases increase with the depth of the primary tumor. Patients with lymphatic metastases can be cured particularly if there are fewer than four nodes involved. Curative surgical therapy necessitates wide lymph node resection to ensure removal of all metastatic nodes.

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.

Living-related donor lobectomy for bilateral lobar transplantation in patients with cystic fibrosis

Donor lobectomy has been performed in 14 patients enabling 7 recipients with cystic fibrosis to undergo bilateral living-related lobar pulmonary transplantation. Donors included 11 patients, 2 brothers, and 1 uncle. Donor mean age was 43 years (range 24 to 55 years). Their mean height and weight was 170 cm (range, 169 to 180 cm) and 72.4 kg (range, 55 to 90 kg), respectively, compared with 161 cm (range, 140 to 175 cm) and 42.4 kg (range, 27 to 55 kg), respectively, in the recipient group. Donor pulmonary evaluation consisted of a history and physical examination, chest roentgenogram and computed tomographic scan, spirometry with arterial blood gas measurement, echocardiography, and perfusion scanning. From each pair of donors, one was selected for right lower lobectomy and the other for left lower lobectomy. Standard lobectomy techniques were modified to facilitate implantation and optimize preservation of the donor lobes. On the right side, the middle lobe was removed and discarded in the first three donors to provide an adequate cuff of pulmonary artery and bronchus for implantation. With increased experience, this has proved not to be necessary. There have been no deaths and no long-term complications in the donor group. Prolonged postoperative air leaks occurred in the 3 patients who underwent right lower and middle lobectomies. All donors have been able to resume their previous lifestyles. Living-related donor lobectomy provides an alternative to cadaveric organs in select patients in need of pulmonary transplantation.

Selection of patients for curative or palliative resection of esophageal cancer based on preoperative endoscopic ultrasonography

OBJECTIVE

To assess the accuracy of pretreatment staging and the potential of using endosonographic findings to select patients for curative or palliative resection by comparing the preoperative endosonographic and computed tomographic (CT) findings with the histology of the surgical specimen.

METHODS

Forty-two patients referred to our clinic with esophageal carcinoma underwent preoperative upper endoscopy with biopsy, endosonography, thoracic CT, and abdominal CT. Based on endoscopic ultrasonographic findings, patients with early-stage disease underwent en-bloc esophagogastrectomy, whereas those with advanced disease had a palliative transhiatal esophagectomy. Exceptions included patients with poor physiologic reserve who were treated by the transhiatal route.

RESULTS

In eight patients, we were unable to pass the ultrasonographic endoscope. Seven of these eight had transmural tumors with nodal involvement on histologic study. Tumor length, based on endosonographic measurements, was correctly predicted in 34 patients (85%). Extent of wall penetration was accurately predicted in 26 (76%) of the 34, and regional lymph node status was accurately predicted in 28 (82%) of the 34. Of the patients with sonographic wall penetration, 80% had histologic evidence of one or more positive nodes. Using the WNM staging system, endoscopic ultrasonography correctly staged the cancer in 68% of the patients. Three patients were treated with an inappropriate procedure.

CONCLUSION

Endosonography is a reliable method for the preoperative staging and selection of patients for curative or palliative resection. Endosonographic wall penetration appears to be a critical factor in determining tumor spread.

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.

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.

Alkaline gastroesophageal reflux: assessment by ambulatory esophageal aspiration and pH monitoring

The pathophysiologic effect of duodenal contents in the refluxed gastric juice of patients with gastroesophageal reflux disease (GERD) is controversial. We evaluated the composition of the refluxed gastric juice in 43 normal volunteers and 52 patients with GERD using a newly developed device that allows ambulatory esophageal aspiration. The findings were correlated with the results of 24-hour esophageal pH monitoring and the presence of complications of GERD. Compared with bile concentrations in normal volunteers, the total bile acid concentration in the reflux aspirates was higher in patients with GERD (p < 0.01). There was a significant correlation between the bile acid concentration in the aspirates and the percentage of time the pH was above 7 on ambulatory 24-hour esophageal pH monitoring (r = 0.59, p = 0.006), and both were highest during the night (p < 0.01). The bile acid concentration and the percentage of time pH was greater than 7 were particularly increased in patients with strictures or Barrett's esophagus (p < 0.01). Both an increased bile acid concentration in aspirates and the percentage of time with pH greater than 7 on pH monitoring were observed primarily in patients with a destroyed gastroduodenal barrier [status post Billroth II resection (BII), Billroth I resection (BI), or pyloroplasty] or after cholecystectomy. An increased bile acid concentration also occurred in a substantial number of patients without previous foregut surgery, although this did not usually result in an increase in the time that pH was above 7. These data suggest that contamination of the refluxed gastric juice with bile acids predisposes the patient to the development of strictures and Barrett's esophagus. An increased time that pH is greater than 7 on esophageal pH monitoring indicates biliary reflux and occurs primarily after previous foregut surgery. A normal-time pH above 7 does, however, not exclude contamination of the refluxed gastric juice with duodenal contents.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

Manual verification of computer analysis of 24-hour esophageal motility

The application of solid-state technology to intraesophageal pressure monitoring over an entire circadian cycle has resulted in large amounts of data that require computer analysis. Recently available commercial software has yet to be validated. The aim of this study was to compare the analysis of ambulatory esophageal manometry by an automated computer program with manual analysis and make the software modifications necessary to validate the automated system for clinical use. Computer-aided analysis of a large number of esophageal contractions recorded during ambulatory esophageal manometry was compared with manual analysis by four experienced physicians. Good correlations were found between manual and computerized measurements of contraction amplitude and duration (r = 0.99 and r = 0.73, respectively). Software modifications resulted in correct identification of 94% of contractions and correct classification of 93.3% of these waves as peristaltic or simultaneous. These results demonstrate that the evaluated program for automated analysis of ambulatory esophageal manometry is accurate and reliable for research and clinical applications.

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.

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.

Foreign body entrapment in the esophagus of healthy subjects--a manometric and scintigraphic study

Foreign body entrapment and mucosal injury caused by oral medications are increasingly reported to occur in the upper esophagus in apparently normal subjects. We performed esophageal manometry in 40 normal volunteers to determine whether a unique motility pattern in the upper third of the esophagus predisposes to entrapment of foreign bodies at this site; 18 normal volunteers also had transit scintigraphy of a gelatin capsule filled with a radionuclide. The esophageal body was divided into five consecutive segments starting proximally, with each segment corresponding to 20% of the total length. Amplitude, slope, and velocity of the esophageal contraction were markedly decreased in the second segment compared with the other segments. Entrapment and dissolution of a gelatin capsule occurred in 39% of volunteers in the proximal esophagus correlating to the second segment, i.e., the segment with the lowest amplitude, slope, and velocity of esophageal contractions. The observation that wet swallows have greater amplitudes (P less than 0.01) and steeper slopes (P less than 0.05) than dry swallows explains why the occurrence of pill entrapment was reduced when taken with sufficient water. However, even with a water chaser of 120 mL, pill entrapment occurred at the second segment of the esophagus in 1 of 18 volunteers. The observed motility pattern in the proximal esophagus provides a better explanation for the entrapment of foreign bodies at this site than compression of the esophagus by the left main stem bronchus, aortic arch, or left atrium as suggested by other investigators.

Concentration of refluxed acid and esophageal mucosal injury

The hallmark of gastroesophageal reflux disease (GERD) is an increase in esophageal exposure to gastric juice. This exposure can result in complications such as esophagitis, stricture, and Barrett's esophagus. The aim of this study is to determine if there are specific pH exposure patterns that are associated with the development of these complications. The 24-hour esophageal pH data for 50 normal subjects and 154 patients with proven GERD were analyzed for time spent at different pH intervals. Increased esophageal acid exposure at a given interval occurred when the cumulative time of exposure exceeded the 95th percentile of that measured in the 50 normal subjects for that interval. The greatest prevalence of mucosal damage was found in the those patients with increased esophageal exposure to pH 0 to 2, corresponding to the known pKa of pepsin. This exposure was not related to a hypersecretory state. In addition, mucosal injury was associated with an increased esophageal exposure to pH 7 to 8. We conclude that mucosal injury in patients with GERD is related to the exposure time to gastric juice with a pH of less than 2 or greater than 7.

Clinical value of endoscopy and histology in the diagnosis of duodenogastric reflux disease

BACKGROUND

The endoscopic observation of a bile lake in the stomach, antral gastritis, or ulcerations and the histologic finding of foveolar hyperplasia or chronic gastritis have been implicated as indicators of excessive duodenogastric reflux. The accuracy of these criteria was evaluated in 135 patients with nonspecific symptoms in the foregut suggestive of duodenogastric reflux and no evidence for alcohol- or drug-induced gastric mucosal injury.

METHODS

The presence of excessive duodenogastric reflux was objectively determined by means of both gastric pH monitoring and cholescintigraphy with cholecystokinin stimulation.

RESULTS

Endoscopy showed antral gastritis in 67 patients, gastric ulcers in 19, and a bile lake in the stomach in 39 (total of 135 patients). Of 90 patients who underwent biopsy, histologic findings showed foveolar hyperplasia in 26, chronic gastritis in 19, and active gastritis in 28 patients. The latter condition was associated with Helicobacter pylori in 20 patients. When gastric pH monitoring, cholescintigraphy, or both were used as "gold standard," the sensitivity, specificity, accuracy, and positive predictive value of endoscopic and histologic criteria to diagnose the presence of excessive duodenogastric reflux were poor except in the rare case of active gastritis but no Helicobacter pylori.

CONCLUSIONS

The presence of duodenogastric reflux disease cannot be accurately diagnosed with endoscopic or histologic criteria. The diagnosis should be made with objective techniques, particularly when surgical therapy is considered.

Physiologic assessment and surgical management of diffuse esophageal spasm

The physiologic abnormalities and management of patients with diffuse esophageal spasm are controversial. We evaluated the symptomatic and functional results of surgical therapy in 19 patients with diffuse esophageal spasm who were incapacitated with dysphagia and chest pain and unresponsive to conservative management. A long esophageal myotomy with an antireflux procedure was performed in 15 patients, and four patients with multiple previous esophageal procedures had an esophagectomy. Eleven patients had increased esophageal exposure to gastric juice on preoperative 24-hour esophageal pH monitoring. The severity of dysphagia, chest pain, regurgitation, and heartburn was scored on a scale of 0 to 3 before and a mean of 24 months (range 8 months to 13 years) after the operation. After myotomy, each of these symptoms and the overall symptom score improved significantly (p < 0.01). The improvement in the symptom scores in the patients who had esophagectomy were comparable with the improvement after myotomy. On self-assessment, 90% of the patients would have the operation again if again faced with the decision. Standard and ambulatory 24-hour manometry showed a significant reduction in the amplitude of the esophageal body contractions, a decrease in the frequency of simultaneous contractions, and the elimination of multi-peaked waves after the myotomy. Despite the addition of an antireflux procedure, lower esophageal sphincter pressure, overall length, and abdominal length were reduced markedly after the myotomy. This was associated with persistent or emerging heartburn or regurgitation in four patients. These data indicate that a long esophageal myotomy is a valid treatment alternative in appropriately selected patients with diffuse esophageal spasm. Esophagectomy and colon interposition is the procedure of choice in patients with multiple previously failed myotomies.

Ambulatory 24-h esophageal pH monitoring: normal values, optimal thresholds, specificity, sensitivity, and reproducibility

Ambulatory 24-h esophageal pH monitoring is increasing in popularity as the means to measure esophageal exposure to gastric juice and document the presence of gastroesophageal reflux disease, particularly before surgical therapy. Normal values for pH exposure were obtained from 50 asymptomatic healthy subjects. Receiver operating characteristic curves constructed from another 25 asymptomatic healthy subjects and 25 selected patients with other markers of increased esophageal acid exposure showed that a composite score and the percent total time pH less than 4 provide the most efficient interpretation of the test with a sensitivity of 96%, a specificity of 100% and an accuracy of 98% for the composite score, and a sensitivity, specificity, and accuracy of 96% for the percent total time pH less than 4. Repeat monitoring of healthy volunteers and symptomatic subjects in the inpatient and outpatient environment showed no significant difference, with the exception that the number of reflux episodes was significantly greater during the outpatient recording in volunteers. This did not affect the clinical accuracy of the test. Esophageal pH probes were well tolerated, but caused belching and coughing during the early part of the monitored period. We conclude that computerized ambulatory 24-h esophageal pH monitoring in the outpatient setting provides accurate and reproducible results.

Neuropeptide release from the isolated, perfused, lower esophageal sphincter region of the rabbit and the effect of vasoactive intestinal peptide on the sphincter

BACKGROUND

The aim was to evaluate the isolated, vascularly perfused, lower esophageal sphincter (LES) as a model for investigating the functional role of neuropeptides such as vasoactive intestinal peptide (VIP).

METHODS

At laparotomy the LES was removed along with the distal esophagus, stomach, and left gastric artery and vein. The LES area, isolated from the body of the stomach by a custom-made clamp, was perfused with oxygenated Krebs-Ringer bicarbonate solution (pH 7.4, 38 degrees C) via the left gastric artery. The LES pressure was monitored continuously with a custom-made Dent sleeve catheter. LES pressure and release of neuropeptides were investigated after carbachol and VIP were administered alone or in combination. VIP, calcitonin gene-related peptide (CGRP), and somatostatin were measured in the venous perfusate collected from the left gastric vein.

RESULTS

LES tone and contraction frequency were similarly increased by 10 and 100 nmol/L carbachol (increment, 4.0 +/- 0.26 mm Hg with 10 nmol/L carbachol; p less than 0.0003). Perfusion with 10 nmol/L VIP decreased basal tone and completely abolished the contraction induced by 100 nmol/L carbachol. VIP, CGRP, and somatostatin were released from the LES in response to 10 nmol/L carbachol (VIP rose from 55 +/- 13 to 179 +/- 24 pmol/L, CGRP, from 114 +/- 30 to 239 +/- 33 pmol/L, and somatostatin from 15 +/- 2 to 27 +/- 4 pmol/L; all p less than 0.001).

CONCLUSIONS

These findings support a role for VIP in the inhibitory reflex of the LES but suggest that other neuropeptides may also be involved. The isolated, perfused LES provides a new tool for investigating neuropeptide interactions.

Complications of gastroesophageal reflux disease. Role of the lower esophageal sphincter, esophageal acid and acid/alkaline exposure, and duodenogastric reflux

The factors contributing to the development of esophageal mucosal injury in gastroesophageal reflux disease (GERD) are unclear. The lower esophageal sphincter, esophageal acid and acid/alkaline exposure, and the presence of excessive duodenogastric reflux (DGR) was evaluated in 205 consecutive patients with GERD and various degrees of mucosal injury (no mucosal injury, n = 92; esophagitis, n = 66; stricture, n = 19; Barrett's esophagus, n = 28). Manometry and 24-hour esophageal pH monitoring showed that the prevalence and severity of esophageal mucosal injury was higher in patients with a mechanically defective lower esophageal sphincter (p less than 0.01) or increased esophageal acid/alkaline exposure (p less than 0.01) as compared with those with a normal sphincter or only increased esophageal acid exposure. Complications of GERD were particularly frequent and severe in patients who had a combination of a defective sphincter and increased esophageal acid/alkaline exposure (p less than 0.01). Combined esophageal and gastric pH monitoring showed that esophageal alkaline exposure was increased only in GERD patients with DGR (p less than 0.05) and that DGR was more frequent in GERD patients with a stricture or Barrett's esophagus. A mechanically defective lower esophageal sphincter and reflux of acid gastric juice contaminated with duodenal contents therefore appear to be the most important determinants for the development of mucosal injury in GERD. This explains why some patients fail medical therapy and supports the surgical reconstruction of the defective sphincter as the most effective therapy.

Immunosuppression in patients with Barrett's esophagus

BACKGROUND

Patients with Barrett's esophagus have a higher incidence of esophageal cancer than has the general population. Local tissue injury and exposure to carcinogens presumably play a role in malignant transformation, but the possibility of altered host immune surveillance must also be considered.

METHODS

The level of immunoreactivity was investigated in six healthy control subjects; 14 patients with gastroesophageal reflux, seven with and seven without esophagitis; and nine patients with Barrett's esophagus. Parameters studied were (1) T-cell and B-cell function with mitogen-stimulated lymphocyte blastogenesis, (2) immunosuppressive properties of autologous serum, and (3) interleukin-2 production by peripheral blood mononuclear cells. Nutritional status as a possible cause for immunosuppression was assessed by measurement of serum albumin, transferrin, and prealbumin.

RESULTS

Patients with Barrett's esophagus had a significant suppression of all T-cell (p less than 0.01) and B-cell function (p less than 0.01) and interleukin-2 production (p less than 0.001) when they were compared to the controls. Interleukin-2 production was also reduced significantly compared to that in patients with gastroesophageal reflux with and without esophagitis (p less than 0.05). No differences were observed in serum immunosuppression or nutritional factors.

CONCLUSIONS

Although the immunosuppression observed in the patients with Barrett's esophagus was milder than that found in other immunocompromised states, it may be sufficient to encourage the malignant transformation of Barrett's mucosa.

Effect of Nissen fundoplication on esophageal motor function

The effect of Nissen fundoplication on the compromised esophageal body function in patients with gastroesophageal reflux disease is poorly understood. Stationary manometry of the distal esophageal body was performed in 50 normal volunteers and compared with that in 40 patients with increased esophageal acid exposure. The studies were performed before and 11 to 68 months (median, 30 months) after successful reflux control and healing of acute mucosal injury with Nissen fundoplication. Before the operation, patients had a lower mean amplitude of contractions, higher prevalence of low amplitude, and interrupted and simultaneous contractions in the distal esophagus compared with normal volunteers. Nissen fundoplication restored the lower esophageal sphincter to normal, increased contraction amplitude, and reduced the prevalence of low-amplitude contractions but did not improve contraction amplitude in patients with a mean amplitude below 35 mm Hg. Fundoplication improves esophageal contraction amplitude but should be performed before the mean contraction amplitude falls below 35 mm Hg.

Normal 24-hr ambulatory esophageal pH values. Influence of study center, pH electrode, age, and gender

Although the most sensitive and specific test for diagnosing gastroesophageal reflux disease, normal standards for prolonged esophageal pH monitoring are based on small sample sizes with questions raised about the effects of pH electrode, older age, gender, and methods of data analysis on pH variables. Recently three groups have established normal data bases using similar methodology. Multiple regression and nonparametric analyses showed that the values for the six traditional pH parameters were comparable across study centers. Therefore, the groups were combined for a total study population of 110 healthy subjects (47 men, 63 women, mean age 38 years with a range of 20-84 years). Further nonparametric analyses revealed the following: (1) type of pH electrode (antimony vs glass) is not significantly related to parameters of physiologic acid reflux; (2) age is not independently related to pH parameters; (3) men tend to have more physiologic reflux than women; and (4) older men tend to experience longer episodes of reflux than younger men and women. There was a significant effect of gender and a significant interaction between age and gender on the number of episodes greater than 5 min (P = 0.008). Nearly significant differences were found for percentage of total acid exposure time (P = 0.03), total reflux episodes (P = 0.02), and the longest reflux episode (P = 0.02). We believe these normal esophageal pH values can be used confidently as standards in any laboratory, and consideration should be given to developing separate standards for men and women.

Therapy of noncardiac chest pain: is there a role for surgery?

Esophageal distention, motor abnormalities, or exposure of the esophageal mucosa to acidic gastric juice can cause chest pain indistinguishable from that of myocardial ischemia in patients with and without coronary artery disease. In these situations the exact cause of the symptom needs to be established prior to any surgical therapy. An antireflux procedure relieves chest pain in patients with increased esophageal acid exposure more reliably than medical therapy. The best results are obtained in patients in whom a direct correlation of the symptom with reflux episodes can be documented on 24-hour esophageal pH monitoring. Ambulatory 24-hour esophageal motility monitoring shows that esophageal motor disorders are a less frequent cause of noncardiac chest pain than suggested by standard manometry or provocation tests. Furthermore, chest pain episodes in patients with esophageal motor abnormalities are not associated with single contractions of excessively high amplitude or duration. Rather, the symptom appears to be triggered by an increased frequency of simultaneous, multipeaked, and repetitive motor activity. In appropriately selected patients with chest pain and dysphagia secondary to an esophageal motor abnormality, a long esophageal myotomy eliminates the ability of the esophagus to produce these contractions, reduces or eliminates dysphagia, and decreases the frequency and severity of chest pain episodes.

Nonobstructive dysphagia in gastroesophageal reflux disease: a study with combined ambulatory pH and motility monitoring

Nonobstructive dysphagia is a common symptom of gastroesophageal reflux disease, and may be present in up to 45% of patients. To elucidate the mechanism of dysphagia, stationary and ambulatory motility studies were performed in 10 controls and 27 patients with gastroesophageal reflux disease. Sixteen patients had nonobstructive dysphagia and 11 had no dysphagia. During stationary studies, there was essentially no difference in esophageal body motility among all the groups. Lower esophageal sphincter manometry was similar in patients with or without dysphagia. On ambulatory motility, about 40% of contractions in the body of the esophagus were simultaneous in the supine position in controls and both groups of patients. The rate of simultaneous contractions decreased in the upright position and at mealtimes in controls and in patients without dysphagia, but not in those with dysphagia. This resulted in a higher percentage (38%) of intraprandial simultaneous wave activity in patients with dysphagia than in those without dysphagia (23%) or in controls (13%) (p less than 0.05). Patients with reflux disease who suffer from nonobstructive dysphagia therefore have a motility disorder measurable on ambulatory motility studies which results in an increased percentage of nonperistaltic (simultaneous wave) activity during mealtimes.

Duodenoesophageal reflux and the development of esophageal adenocarcinoma in rats

BACKGROUND

The carcinogenic effect of duodenoesophageal reflux, gastroesophageal reflux, and nitrosamines was studied in the rat esophagus.

METHODS

Twenty male Sprague-Dawley rats underwent esophagogastroplasty to produce gastroesophageal reflux and 60 underwent duodenoesophageal anastomosis to produce duodenoesophageal reflux. Forty-three animals underwent no operation and acted as controls. Carcinogens known to produce squamous tumors in the rat esophagus (2,6-dimethylnitrosomorpholine [DMNM] or methyl-n-amylnitrosamine [MNAN]) were tested in each group.

RESULTS

The rate of squamous carcinoma was 25% for rats with DMNM alone, 30% for rats with MNAN alone, and 20% for rats with induced gastroesophageal reflux plus DMNM. The rate of malignant change rose to 80% in rats with induced duodenoesophageal reflux and DMNM and 67% with duodenoesophageal reflux and MNAN. With duodenoesophageal reflux, 50% of tumors were adenocarcinoma, in contrast to 100% squamous differentiation of tumors in rats given the carcinogens with esophagogastroplasty or no operation.

CONCLUSION

The presence of duodenoesophageal reflux increased the frequency and changed the histologic type of esophageal cancer in nitrosamine-treated rats. This indicates that duodenoesophageal reflux plays a role in the development of esophageal adenocarcinoma.