Denervated stomach as an esophageal substitute recovers intraluminal acidity with time

Duodenogastric reflux after esophagectomy and gastric pull-up: the effect of the route of reconstruction

Duodenogastric reflux (DGR) is a common sequel of subtotal esophagectomy and gastric pull-up, and it may contribute to mucosal changes of both the gastric conduit and the esophageal remnant. This study investigated the effect of the route of reconstruction on the DGR. 24-hour ambulatory bilirubin monitoring was performed on patients who underwent transhiatal subtotal esophagectomy and a gastric tube interposition either in the posterior mediastinum (PM group, n = 11), or in the retrosternal space (RS group, n = 8): A Control group of 8 healthy volunteers was also studied. The median percentage of reflux time, the median number of reflux episodes, and the median number of reflux episodes longer than 5 minutes, in PM versus RS groups, were 29.1% versus 0.15% (p < 0.001), 185 versus 8 (p = 0.002) and 10 versus 0 (p = 0.001), respectively. The values of the above variables in PM versus control groups were 29.1% versus 3.95% (p = 0.007), 185 versus 21 (p = 0.02), and 10 versus 2 (p = 0.009), respectively, whereas in RS versus control groups they were 0.15% versus 3.95% (p = 0.01), 8 versus 21 (p = 0.04), and 0 versus 2 (p = 0.05), respectively. Posterior mediastinal gastric interposition is associated with high reflux of duodenal contents, whereas retrosternal interposition minimizes the reflux at levels even lower than those of the healthy individuals. The latter type of reconstruction may be a good alternative from that perspective, especially in patients with long life expectancy.

Acid and duodenogastroesophageal reflux after esophagectomy with gastric tube reconstruction

OBJECTIVE

Patients who undergo esophagectomy with gastric tube reconstruction incur increased risk for acid reflux and duodenogastroesophageal reflux. Few postesophagectomy studies of gastroesophageal reflux disease have included simultaneous 24-h pH and bilirubin monitoring. The aim of this study is to evaluate acid reflux and duodenogastroesophageal reflux after esophagectomy with gastric tube reconstruction.

METHODS

Reflux symptom evaluation, endoscopy, and simultaneous 24-h pH and bilirubin monitoring in the cervical esophagus were performed in 25 patients who underwent Ivor Lewis esophagectomy, intrathoracic esophagogastrostomy, and digital dilation of the pyloric ring as treatment for esophageal cancer.

RESULTS

Reflux symptoms were severe, mild, and absent in 2, 7, and 16 patients, respectively. Reflux esophagitis and Barrett's esophagus was observed in 11 and 1 patients, respectively. Elevated acid reflux occurred in 7 patients (28%). Elevated duodenogastroesophageal reflux was recorded in 11 patients (44%). Reflux profile analysis identified three patterns: 4 subjects (16%) with both elevated acid reflux and duodenogastroesophageal reflux; 3 (12%) with only elevated acid reflux; and 7 (28%) with only elevated duodenogastroesophageal reflux. Of 7 patients with only elevated duodenogastroesophageal reflux, 4 developed reflux esophagitis. Although reflux symptoms did not correlate with endoscopic esophagitis, a significant correlation was observed between endoscopic esophagitis and acid reflux and/or duodenogastroesophageal reflux.

CONCLUSIONS

Reflux symptoms represented a poor indication of esophagitis in patients with esophagectomy and gastric tube reconstruction. Simultaneous 24-h pH and bilirubin monitoring can help in identifying patients at high risk for reflux esophagitis, as well as indicating the cause of esophagitis.

Colonic interposition vs. gastric pull-up after total esophagectomy

Gastric pull-up is the most frequent reconstruction after esophagectomy. In this report we aimed to compare gastric pull-up with colonic interposition in terms of graft function and patient satisfaction. Of 62 patients undergoing esophagectomy, reconstruction was performed by colonic interposition in 11 and gastric pull-up in 51 (without pyloric drainage in 44 and with pyloric drainage in 7). All esophagectomies were performed transhiatally. Patient follow-up ranged from 6 to 132 months (median 14 months). Follow-up examinations were performed 1, 9, 15, and 24 months postoperatively. The following factors were evaluated: time to the start of oral liquid and solid nutrients without vomiting, frequency of regurgitation, presence of pillow staining (night regurgitation), postprandial fullness, and degree of satisfaction during and after eating compared between groups undergoing colonic interposition and gastric pull-up with or without pyloric drainage. Among patients undergoing gastric pull-up, regurgitation was observed in 22% to 27% during follow-up. None of the patients with colonic interposition had reflux or regurgitation. Twenty-five percent of patients with gastric pull-up without drainage and 66% of patients with gastric pull-up plus drainage had reflux esophagitis at 15 months. No esophagitis was observed in patients with colonic interposition during the same period. Overall satisfaction was superior in patients undergoing colonic interposition followed by gastric pull-up with no drainage. Colonic interposition after esophageal resection is a viable option. Our study suggests that function of the replacement is better in this group of patients.

Recurrent Barrett's esophagus and adenocarcinoma after esophagectomy

Background

Esophagectomy is considered the gold standard for the treatment of high-grade dysplasia in Barrett's esophagus (BE) and for noninvasive adenocarcinoma (ACA) of the distal esophagus. If all of the metaplastic epithelium is removed, the patient is considered "cured". Despite this, BE has been reported in patients who have previously undergone esophagectomy. It is often debated whether this is "new" BE or the result of an esophagectomy that did not include a sufficiently proximal margin. Our aim was to determine if BE recurred in esophagectomy patients where the entire segment of BE had been removed.

Methods

Records were searched for patients who had undergone esophagectomy for cure at our institution. Records were reviewed for surgical, endoscopic, and histopathologic findings. The patients in whom we have endoscopic follow-up are the subjects of this report.

Results

Since 1995, 45 patients have undergone esophagectomy for cure for Barrett's dysplasia or localized ACA. Thirty-six of these 45 patients underwent endoscopy after surgery including 8/45 patients (18%) with recurrent Barrett's metaplasia or neoplasia after curative resection.

Conclusion

Recurrent Barrett's esophagus or adenocarcinoma after esophagectomy was common in our patients who underwent at least one endoscopy after surgery. This appears to represent the development of metachronous disease after complete resection of esophageal disease. Half of these patients have required subsequent treatment thus far, either repeat surgery or photodynamic therapy. These results support the use of endoscopic surveillance in patients who have undergone "curative" esophagectomy for Barrett's dysplasia or localized cancer.

Antireflux anastomosis following oesophagectomy

BACKGROUND

Reflux of duodeno-gastric fluid is a significant problem after oesophagectomy with gastric conduit reconstruction. It can impact considerably upon the patient's quality of life and can induce oesophagitis and Barrett's metaplasia in the remnant oesophagus.

AIM

The aim of the present study was to describe the use of a modified fundoplication in controlling reflux after oesophagectomy.

METHODS

Patients undergoing subtotal oesophagectomy at the Royal Adelaide Hospital were identified. Clinical and operative details were obtained from hospital records. All patients had an end oesophagus to side stomach anastomosis. Two cohorts were identified - one with a standard anastomosis only and the other in whom a modified fundoplication had been added. A structured phone interview was used to assess reflux in the two groups with a minimum of 6 months follow up. The interviewer was blinded to the operative details.

RESULTS

The operative technique is described. A total of 44 patients were assessed, 33 having the fundoplication type anastomosis and 11 the standard anastomosis. Operative morbidity was not different between the groups. Symptoms of reflux were better controlled in patients with the fundoplication anastomosis than in patients with a standard anastomosis. Of those with a fundoplication, 14 of 33 patients (42%) were asymptomatic with respect to reflux compared to only one of 11 patients (9%) in the standard anastomosis group. Only four of the 33 patients (12%) with a fundoplication anastomosis had symptoms of severe reflux while seven of the 11 patients (63%) with a standard anastomosis had severe reflux symptoms.

CONCLUSIONS

This initial evaluation of a modified fundoplication as an antireflux manoeuvre after oesophagectomy suggests that the technique is effective in controlling post-oesophagectomy reflux in the majority of patients. It is simple to perform and may have benefits in improving quality of life and preventing oesophagitis and metaplastic changes in the remnant oesophagus. A more detailed prospective study of the technique is warranted.

Manometric evaluation of the intrathoracic stomach after gastric transposition in children

Gastric transposition (GT) is one of the options for the esophageal replacement in children with esophageal atresia with or without tracheoesophageal fistula (EATEF). To date, no manometric studies have been conducted on the intrathoracic stomach after GT in EATEF patients; hence, this study was designed. Babies ( n=18) of EATEF who underwent esophageal replacement by GT were studied and manometry was correlated with the clinical outcome, age at surgery, and route of GT. The mean age at evaluation was 30.5 months (range 4-84 months). These cases were sub-stratified into group I (GT during neonatal period) and group II (GT during post-neonatal period). Mean age at surgery was 6 days and 7.8 months in groups I and II, respectively. There was no propulsive antegrade propagated peristaltic waves in any of the patients. Mean resting pressure and mean peak pressures were 19.5 and 50.4 mm Hg in groups I and II, respectively. Mass contractions to liquid swallow was noted in 77 and 55% of patients in groups I and II, respectively. There was no significant difference in the pressure parameters or appearance of mass contractions between group-I and group-II patients. Similarly, there was no significant difference in pressure parameters or appearance of mass contractions between the children who had transhiatal vs retrosternal GT. It needs to be determined whether the mass contractions noted in GT ever progress to a coordinated propulsive rhythmic contractions and whether this has a final bearing on the long-term functional outcome of GT patients.

Whole stomach with antro-pyloric nerve preservation as an esophageal substitute: an original technique

The paper describes an original technique of gastric tailoring in which the two-thirds of the lesser curvature proximal to the crow's foot are denuded flush with the gastric wall, leaving both nerves of Latarjet and the hepatic branches of the left vagus nerve intact. Maintenance of the vagal supply to the antro-pyloric segment in two patients resulted in the presence of peristaltic contractions sweeping over the antrum on simple observation of the antral wall at the end of the procedure and on both upper G-I series and intragastric manometry tracings 6 weeks postoperatively. Gastric exposure to bile on 24-h gastric bile monitoring was normal 6 weeks after the operation. Neither patient had any gastrointestinal symptoms with the exception of early sensations of postprandial fullness when overeating.

Tissue engineering of the gastrointestinal tract for surgical replacement: a nutrition tool of the future?

Optimal nutrition depends on the multiple complex functions performed by the gastrointestinal tract, which range from basic functions such as storage, conduit and mechanical processing to more finely regulated capabilities such as vectorial transport, immune defence and cell signalling. Surgical strategies to supply lacking gastrointestinal tract tissues have relied on either replacement by proxy (surgical substitution) or the introduction of prostheses. Tissue engineering seeks to replace missing tissues with engineered tissues that more accurately reproduce the native physiological and anatomical milieu. It is now possible to engineer several areas of the gastrointestinal tract with high fidelity, and to employ tissue-engineered bowel in replacement in animal models. These replacement models have reflected excellent anatomical and physiological recapitulation of native bowel by the tissue-engineered constructs in vivo.

Factors influencing the development of Barrett's epithelium in the esophageal remnant postesophagectomy

BACKGROUND

Barrett's esophagus results from chronic reflux of both acid and bile. Reflux of gastric and duodenal contents is facilitated through the denervated stomach following esophagectomy, but the development of Barrett's changes in this model and the relationship to gastric and esophageal physiology is poorly understood.

AIMS

To document the development of new Barrett's changes, i.e., columnar metaplasia or specialized intestinal metaplasia (SIM) above the anastomosis, and relate this to the recovery of gastric acid production, acid and bile reflux, manometry, and symptoms.

PATIENTS AND METHODS

Forty-eight patients at a median follow-up of 26 months (range = 12-67) postesophagectomy underwent endoscopy with biopsies taken 1-2 cm above the anastomosis. The indication for esophagectomy had been adenocarcinoma (n = 27), high-grade dysplasia (n = 2), and squamous cell cancer (n = 19). Physiology studies were performed in 27 patients and included manometry (n = 25), intraluminal gastric pH (n = 24), as well as simultaneous 24-hour esophageal pH (n = 27) and bile monitoring (n = 20).

RESULTS

Duodenogastric reflux increased over time, with differences between patients greater than and less than 3 years postesophagectomy for acid (p = 0.04) and bile (p = 0.02). Twenty-four patients (50%) developed columnar metaplasia and of these 13 had SIM. The prevalence of columnar metaplasia did not relate to the magnitude of acid or bile reflux, to preoperative neoadjuvant therapies, or to the original tumor histology. The duration of reflux was most significant, with increasing prevalence over time, with SIM in 13 patients at a median of 61 months postesophagectomy compared with 20 months in the 35 patients who were SIM-negative (p < 0.006). Supine reflux correlated with symptoms.

CONCLUSIONS

The development of Barrett's epithelium is frequent after esophagectomy, is time-related, reflecting chronic acid and bile exposure, and is not specific for adenocarcinoma or the presence of previous Barrett's epithelium. This model may represent a useful in vivo model of the pathogenesis of Barrett's metaplasia and tumorigenesis.

Reflux after oesophagectomy

Background

Reflux of gastric and duodenal content after oesophagectomy with gastric conduit reconstruction is a common problem and largely considered an inevitable consequence of surgery. Cervical burning and regurgitation, often more pronounced when supine, can be troublesome and even disabling, interfering substantially with quality of life. The aim of this study was to identify the factors contributing to reflux after oesophagectomy and evaluate measures to prevent or control it.

Methods

A Medline search using the terms ‘gastro-oesophageal reflux’, ‘oesophagectomy’ and ‘antireflux surgery’ was conducted. Additional references and search pathways were sourced from the bibliographies of articles located.

Results and conclusion

Reflux after oesophagectomy is a significant problem, with both clinical and pathological consequences. Simple measures to facilitate gastric emptying, such as creating a gastric tube, performing a pyloric drainage procedure and using gastric motility agents, may produce a reduction in symptoms but do not alone control reflux itself. A variety of surgical reconstructions have been used, many of which are either difficult to fashion or not suitable when a radical resection has been performed. A modified fundoplication at the anastomosis seems to be the simplest technique and may be relatively effective in controlling symptoms. The impact of strategies to reduce reflux on quality of life and on pathological sequelae of reflux in the oesophageal remnant remains to be evaluated.

Musings on the wanderer: what's new in our understanding of vago-vagal reflexes? V. Remodeling of vagus and enteric neural circuitry after vagal injury

The vago-vagal reflexes mediate a wide range of digestive functions such as motility, secretion, and feeding behavior. Previous articles in this series have discussed the organization and functions of this important neural pathway. The focus of this review will be on some of the events responsible for the adaptive changes of the vagus and the enteric neutral circuitry that occur after vagal injury. The extraordinary plasticity of the neural systems to regain functions when challenged with neural injury will be discussed. In general, neuropeptides and transmitter-related enzymes in the vagal sensory neurons are downregulated after vagal injury to protect against further injury. Conversely, molecules previously absent or present at low levels begin to appear or are upregulated and are available to participate in the survival-regeneration process. Neurotrophins and other related proteins made at the site of the lesion and then retrogradely transported to the soma may play an important role in the regulation of neuropeptide phenotype expression and axonal growth. Vagal injury also triggers adaptive changes within the enteric nervous system to minimize the loss of gastrointestinal functions resulting from the interruption of the vago-vagal pathways. These may include rearrangement of the enteric neural circuitry, changes in the electrophysiological properties of sensory receptors in the intramural neural networks, an increase in receptor numbers, and changes in the affinity states of receptors on enteric neurons.

Tissue-engineered esophagus: experimental substitution by onlay patch or interposition

OBJECTIVES

We proposed to fabricate a tissue-engineered esophagus and to use it for replacement of the abdominal esophagus.

METHODS

Esophagus organoid units, mesenchymal cores surrounded by epithelial cells, were isolated from neonatal or adult rats and paratopically transplanted on biodegradable polymer tubes, which were implanted in syngeneic hosts. Four weeks later, the tissue-engineered esophagus was either harvested or anastomosed as an onlay patch or total interposition graft. Green Fluorescent Protein labeling by means of viral infection of the organoid units was performed before implantation. Histology and immunohistochemical detection of the antigen alpha-actin smooth muscle were performed.

RESULTS

Tissue-engineered esophagus grows in sufficient quantity for interposition grafting. Histology reveals a complete esophageal wall, including mucosa, submucosa, and muscularis propria, which was confirmed by means of immunohistochemical staining for alpha-actin smooth muscle. Tissue-engineered esophagus architecture was maintained after interposition or use as a patch, and animals gained weight on a normal diet. Green Fluorescent Protein-labeled tissue-engineered esophagus preserved its fluorescent label, proving the donor origin of the tissue-engineered esophagus.

CONCLUSIONS

Tissue-engineered esophagus resembles the native esophagus and maintains normal histology in anastomosis, with implications for therapy of long-segment esophageal tissue loss caused by congenital absence, surgical excision, or trauma.

Outcome of histologically node-negative esophageal squamous cell carcinoma

The outcome of node-negative esophageal carcinoma and the prognostic significance of lymph node micrometastasis remain unknown. The aim of this retrospective study was to clarify these two points. A series of 98 patients who underwent curative operation for histologically node-negative (pN0 in TNM classification) esophageal carcinoma were enrolled in the study. We reviewed the cause of death of these patients. The survival curves were calculated and compared after stratifications according to clinicopathologic parameters. Lymph node micrometastasis in the patients with recurrences was examined using immunohistochemical staining of cytokeratin. Their ages ranged from 45 to 83 years (mean 64.3 years). There were 83 men and 15 women. Altogether, 54 patients were still alive, and 44 had died. A total of 9 patients died from recurrence of their esophageal carcinoma, 33 died from other causes (pneumonia 11, extraesophageal carcinoma 7, and so on), and 2 died from unknown causes. Eight patients had locoregional recurrences, and two patients had distant recurrences. The overall survival rate for the 98 patients was 58.2%. The survival for patients with pT2 or pT3 tumors was significantly worse than for those with pTis or pT1 tumors (p = 0.02, log-rank test). Other clinicopathologic factors did not affect the prognosis. Immunohistochemical study found no lymph node micrometastasis in 365 lymph nodes resected from the patients with recurrences. Only the depth of tumor invasion affected the outcome of patients with node-negative esophageal carcinoma. Altogether, 75% of patients died of other causes without recurrence, with the two main causes of death being pulmonary complications and extraesophageal carcinoma in these patients. Lymph node micrometastasis was not associated with recurrence in this series.

Esophageal carcinoma: surgery, radiotherapy, and chemotherapy

Several new developments in the potentially curative therapy of esophageal cancer have drawn attention over the past year. There is a potential benefit of centralization of esophagectomies in dedicated centers. Early mucosal lesions are increasingly treated by local ablative therapy. Tumors invading the submucosa are preferably treated by surgical resection. There is ongoing controversy about the optimal surgical approach. Positron emission tomography scanning is a promising tool in the preoperative work-up but needs critical evaluation. The question of whether chemoradiation with voice preservation (followed by salvage surgery in case of tumor recurrence) can replace pharyngolaryngectomy in patients with cervical esophageal cancer is still unanswered. A review of eight randomized trials demonstrated that chemoradiation as primary treatment of esophageal cancer provides an absolute reduction of mortality. The addition of new drugs like paclitaxel and irinotecan into induction regimens for the treatment of advanced disease results in higher response rates but also in increased toxicity. Preoperative radiotherapy as single modality treatment does not improve overall survival, whereas the benefit of preoperative chemotherapy and chemoradiation has not been proven unequivocally. Several retrospective studies with a small number of patients suggest that local response parameters like pathologic complete response and downstaging of regional lymph node (N) status are correlated with longer survival.

Metaplastic columnar mucosa in the cervical esophagus after esophagectomy

OBJECTIVE

To evaluate the pathogenesis of metaplastic processes within the esophagus using a human model in which the exact duration of reflux was known.

SUMMARY BACKGROUND DATA

The pathogenesis of Barrett's esophagus (BE) is incompletely understood. Patients undergoing esophagectomy and gastric tube reconstruction represent a good model for studying the pathophysiology of columnar cell metaplasia of the human esophagus because the cervical esophagus is rarely or never exposed to gastric contents before the surgical procedure.

METHODS

Thirty-two patients underwent manometry, simultaneous 24-hour pH and bilirubin monitoring, and endoscopy with biopsy 3 to 10.4 years after esophagectomy. The presence of columnar mucosa in the cervical esophagus was confirmed on histologic examination. The findings on endoscopy and histology were related to clinical data and the results of pH and bilirubin monitoring 1 cm proximal to the esophagogastrostomy.

RESULTS

Fifteen (46.9%) of the 32 patients had metaplastic columnar mucosa within their cervical esophagus. Metaplasia was significantly more common in patients with a preoperative diagnosis of BE. The length of metaplastic mucosa correlated significantly with the degree of esophageal acid exposure, but the presence of abnormal bilirubin exposure was unrelated to the presence of metaplasia. The prevalence of metaplasia did not change with increasing time. Intestinal metaplasia was found within the columnar-lined segment in three patients 8.5, 9.5, and 10.4 years after esophagectomy. All patients with intestinal metaplasia had abnormal exposure of both acid and bilirubin, but the presence of combined reflux was not significantly higher in these patients compared with patients with nonintestinalized segments of columnar mucosa.

CONCLUSIONS

Esophageal columnar metaplasia is a common complication after gastric pull-up esophagectomy. Metaplasia is more likely to develop in patients with previous BE than other patients. Metaplasia develops in response to squamous epithelial injury in predisposed individuals.

High-grade dysplasia in Barrett's esophagus. The case for esophagectomy

The main principles for optimal management of HGD arising in Barrett's esophagus are that unequivocal diagnosis of HGD is a prerequisite for making the decision of any kind of treatment. HGD must be resected because of the presence of neoplastic cells in the lamina propria in 40% of patients. No reliable endoscopic or endosonographic feature exists that allows accurate prediction of the existence of neoplastic cells within the lamina propria of a patient having HGD in endoscopic biopsy material. Prompt decision to remove an HGD lesion as soon as unequivocal histologic diagnosis has been settled prevents the development of extraesophageal neoplastic spread. Esophagectomy is preferable to endoscopic mucosal excision because approximately 20% of patients who have HGD in preoperative biopsy material carry neoplastic cells beyond the muscularis mucosae. Esophagectomy can be limited to the removal of the esophageal tube without extended lymphadenectomy because 96% of patients who have HGD in endoscopic biopsy samples have a neoplastic process confined to the esophageal wall. Esophageal resection must encompass all the Barrett's area because of the risk for the further development of a second cancer in the metaplastic remnant. Vagus-sparing esophagectomy with colon interposition or elevation of the antrally innervated stomach up to the neck is preferable to conventional esophagectomy with gastric pull up because the former procedure maintains gastric function intact, whereas the latter exposes patients to the risk for the long-term development of reflux esophagitis and even of metaplastic transformation of the proximal esophageal remnant. Subtle details in the understanding of a given patient's clinical course may be critical for making the decision of the most relevant mode of therapy; therefore, patients who have HGD should be treated in dedicated centers, the experience of which offers the best chances of uneventful recovery if the surgical option is retained.

Bile exposure of the denervated stomach as an esophageal substitute

BACKGROUND

Both the supine position and the existence of a gastric drainage procedure are suspected to promote reflux of duodenal juice into the denervated intrathoracic stomach. Erythromycin has been shown to weaken pyloric resistance to gastric outflow and to enhance antral motility, gastric emptying, and gallbladder contractility.

METHODS

The presence of bile in the gastric transplant of 79 patients was monitored over a 24-hour period with use of the Bilitec 2000 optoelectronic device 3 to 195 months after subtotal esophagectomy. Ten patients were reinvestigated after a 3-year period. Five groups were studied: group I: n = 12, no gastric drainage, never given erythromycin, group 2: n = 40, gastric drainage, never given erythromycin, group 3: n = 7, no gastric drainage, given erythromycin, group 4: n = 13, gastric drainage, given erythromycin, and group 5: n = 7, no longer given erythromycin (with or without gastric drainage). The percentage of time gastric bile absorbance was more than 0.25 was calculated for the total, supine, and upright periods of recording in reference to data from 25 healthy volunteers.

RESULTS

The Bilitec test was pathologic in 9 of the 12 patients of group 1 whereas it was normal in three. Gastric exposure to bile was longer in group I patients than in controls for the total (p = 0.012) and supine (0.036) periods, but the difference did not reach statistical significance for the upright period (p = 0.080). Bile exposure in group 4 did not significantly differ from controls (total: p = 0.701; supine: p = 0.124; upright: p = 0.712). Bile exposure for the total period did not significantly differ whether patients were taking erythromycin or the drug had been discontinued at the time of the study (p = 0.234); and it tended to decrease with time in patients investigated twice (p = 0.046).

CONCLUSIONS

Gastric exposure to bile after truncal vagotomy and transposition of the stomach up to the neck is pathologic in three quarters of patients. It is more marked in the supine than in the upright position and tends to decrease with time. The addition of a gastric drainage procedure in combination with erythromycin therapy tends to normalize gastric exposure to bile. The effects of erythromycin may persist after discontinuation of the drug.