The distal esophageal sphincter and its relationship to gastroesophageal reflux

Accuracy of the Air Flow Sphincter Locator system in identifying the lower esophageal sphincter for placement of pH catheters

The Air Flow Sphincter Locator (AFSL) is marketed as an alternative method to manometry for localizing the lower esophageal sphincter (LES) for pH probe placement. Such a system is desirable due to the additional time, cost, and discomfort associated with dual nasal intubation, but its accuracy has never been assessed. To assess the accuracy of the AFSL in localizing the LES. Fifty consecutive outpatients presenting for pH and manometry studies were included. The upper border of the LES was determined using HRM and the AFSL by two technicians independently. LES locations measured by technicians using AFSL versus manometry, as well as the manometrically determined LES locations by technicians versus MDs were compared. Differences in LES locations determined by HRM as read by MDs versus technicians were small; none were >3 cm, and 92% were within 2 cm. Comparison between LES locations determined by technicians using HRM versus the AFSL revealed that 52% had a difference of 2-3cm and 32% had a difference of >3 cm. Hiatal hernia was associated with a difference in LES location of >3 cm. Excluding patients with hiatal hernia, nonetheless, still produced a >3 cm difference in 24% of studies. Prior reports have suggested that a difference greater than +/-3 cm in pH probe placement is considered unacceptable for clinical studies. Based on our study, the AFSL placed the LES outside of this range in 32% of patients, and may be particularly inaccurate in the setting of a hiatal hernia. This suggests that the device may not be an acceptable alternative to manometry in determining LES location for pH probe placement.

The University of Chicago contribution to the treatment of gastroesophageal reflux disease and its complications: a tribute to David B. Skinner 1935-2003

OBJECTIVE

To highlight the contributions from the University of Chicago under the leadership of Dr David B. Skinner to the understanding of gastroesophageal reflux disease (GERD) and its complications.

BACKGROUND

The invention of the esophagoscope confirmed that GERD was a premorbid condition. The medical world was divided between those who believed in a morphological lower esophageal sphincter (LES) and those who did not. Those who did not believe attempted to rearrange the anatomy of the foregut organs to stop reflux with minimal success. The discovery of the LES focused attention on the sphincter as the main deterrent to reflux and the hope that measurement of a low LES pressure would mark the presence of GERD. This turned out not to be so. In July 1973, with this history of confusion, Dr Skinner at the age of 36 assumed the chair of surgery at the University of Chicago.

METHODS

The publications of the University of Chicago's esophageal group were collected from private and public (PubMed) databases, reviewed, and seminal contributions selected.

RESULTS

Twenty-four-hour esophageal pH monitoring led to the understanding of the LES, its contribution to GERD, and the complication of Barrett's esophagus. The relationship of Barrett's to adenocarcinoma was clarified. The rising incidence of esophageal adenocarcinoma led to contributions in the staging of esophageal cancer and its treatment with an en bloc resection.

CONCLUSIONS

Ten years after the death of Dr Skinner, we can appreciate the monumental contributions to benign and malignant esophageal disease under his leadership.

Estudo prospectivo comparativo de duas modalidades de posicionamento do sensor de phmetria esofágica prolongada: por manometria esofágica e pela viragem do Ph

RACIONAL: Por padronização aceita internacionalmente, posiciona-se o sensor distal de pHmetria esofágica a 5 cm acima da borda superior do esfíncter inferior do esôfago, localizado por manometria esofágica. Porém, vários autores sugerem técnicas alternativas de posicionamento que prescindem da manometria. Dentre essas, destaca-se a da viragem do pH, tema este controverso pela sua duvidosa confiabilidade. OBJETIVO: Avaliar a adequação do posicionamento do sensor distal de pHmetria pela técnica de viragem do pH, considerando-se a presença, o tipo e o grau de erro de posicionamento que tal técnica proporciona, e também estudar a influência da posição adotada pelo paciente durante a técnica da viragem. MÉTODOS: Foram estudados de modo prospectivo, durante o período de 1 ano, 1.031 pacientes. Durante entrevista clínica, foram registrados os dados demográficos e as queixas clínicas apresentadas. Todos foram submetidos a manometria esofágica para localização do esfíncter inferior do esôfago e a técnica da viragem do pH. A identificação do ponto de viragem foi realizada de dois modos distintos, caracterizando dois grupos de estudo: com o paciente sentado (grupo I - 450 pacientes) e com o paciente em decúbito dorsal horizontal (grupo II - 581 pacientes). Após a identificação do ponto de viragem, o sensor distal de pHmetria era posicionado na posição padronizada, baseada na localização manométrica do esfíncter. Registrava-se onde seria posicionado o sensor de pH se fosse adotada a técnica da viragem. Para avaliação da adequação do posicionamento, considerou-se que o erro é representado pela diferença (em centímetros) entre a localização padronizada (manométrica) e a localização que seria adotada caso fosse empregada a técnica da viragem. Considerou-se que o erro seria grosseiro se fosse maior que 2 cm. Analisou-se também o tipo de erro mais freqüente (se acima ou abaixo da posição padronizada). Foram incluídos todos pacientes que aceitaram participar da pesquisa e excluídos os casos nos quais não se identificou acidificação intragástrica. RESULTADOS: Se fosse adotada a técnica da viragem, haveria erro no posicionamento do sensor em 945 pacientes (91,6%), portanto, o sensor seria posicionado na posição padronizada em apenas 86 (8,4%) casos. Em relação à caracterização do grau de erro, haveria erro considerado grosseiro em 597 (63,2%) pacientes. Em relação ao tipo de erro, o sensor seria posicionado abaixo do local padronizado em 857 (90,7%) casos. Não houve diferença significante entre os dois grupos de estudo em relação a nenhum dos parâmetros analisados, indicando que a posição adotada pelo paciente durante a manobra da viragem não interfere no erro inerente à técnica. CONCLUSÕES: 1. O posicionamento do sensor distal de pHmetria pela técnica da viragem do pH não é confiável. 2. A técnica da viragem proporciona margem de erro expressiva. 3. O tipo de erro mais comum que tal modalidade técnica proporciona é o posicionamento mais distal do sensor, que pode superestimar a ocorrência de refluxo. 4. Não há influência da posição adotada pelo paciente durante a realização da técnica da viragem do pH na eficiência do método.

pH probe positioning for 24-hour pH-metry by manometry or pH step-up

OBJECTIVES

Before pH measurement, manometry is recommended for precise pH probe positioning. We investigated whether the pH probe could be positioned accurately by the pH difference between the oesophagus and the stomach (pH step-up).

METHODS

Dual-channel 24-h pH-metry with probes positioned 5 cm above either the manometrically determined upper lower oesophageal sphincter margin or the pH step-up was performed in healthy volunteers and reflux patients. To determine the pH step-up, the pH probe was pulled back from the stomach until a sudden rise to pH greater than four occurred. Probe position, reflux episodes and the fraction of the time pH was less than four were compared using the Wilcoxon test for difference and the Hodges-Lehman estimate inclusive confidence interval for equivalence. The pH step-up method was evaluated further during proton pump inhibitor therapy and after drug discontinuation.

RESULTS

The pH probe was positioned 2 cm and 1 cm closer to the stomach by the pH step-up method in the volunteers and reflux patients, respectively. A small increase in upright reflux episodes but not in supine reflux episodes was registered by the probe positioned by pH step-up. No significant differences in the fraction of the time pH was less than four were obtained between the two probes. The Hodges-Lehman calculation proved equivalence for both methods of probe positioning for 24-h pH-metry. During proton pump inhibitor therapy, no pH step-up was detectable in three volunteers and in one patient. On the first day after discontinuing therapy, the pH step-up method yielded clear-cut results again.

CONCLUSION

The pH probe for diagnostic 24-h pH-metry and, with some limitations, also for 24-h pH-metry for therapy control, can be positioned accurately by the pH step-up method.

The role of esophageal motility and hiatal hernia in esophageal exposure to acid

BACKGROUND

The pathogenesis of gastroesophageal reflux disease (GERD) is multifactorial. This study evaluates the relationship between esophageal exposure to acid, the presence or absence of a hiatal hernia, and manometric indicators of esophageal motility.

METHODS

A total of 51 patients with foregut symptoms were evaluated with upper gastrointestinal series or endoscopy, 24-h pH testing, and esophageal manometry. The DeMeester score was used to distinguish patients with physiologic reflux (DeMeester score <14.72) patients with pathologic reflux (DeMeester score >14.72).

RESULTS

Patients with physiologic reflux had fewer hypotensive contractions and a smaller percentage of uncoordinated and hypotensive contractions combined, as compared to patients with pathologic reflux. The amplitude of distal esophageal contractions was greater in patients with physiologic reflux. Also, patients with a hiatal hernia had a higher incidence of pathologic reflux, regardless of the lower esophageal sphincter pressure.

CONCLUSION

Patients with pathologic reflux have abnormal acid exposure associated with pump failure of the esophagus and/or a mechanical defect of the cardia associated with a hiatal hernia.

Effects of intraluminal acidification on oesophageal motor activity

This study assessed the effect of prolonged intraluminal acidification on the motor activity of the entire oesophageal body (under controlled conditions). Intraoesophageal pressures were recorded in 13 endoscopy negative subjects with gastro-oesophageal reflux disease in whom saline, HC1 0.1 N, and saline solutions were infused (1.5 ml/min) blindly in the oesophageal body, 6 cm distal to the upper oesophageal sphincter for three consecutive periods of 45 minutes each. These findings were compared with those of a control group. Intraoesophageal acidification caused an increase in the deglutition frequency (p < 0.02), the occurrence of multipeaked waves (p < 0.04) as well as a decrease of the propagating velocity (p < 0.04) of the primary peristaltic contractions. Furthermore, intraoesophageal acidification determined an increase, at all levels of the oesophagus, of the duration (p < 0.04) and, more noticeable in the proximal oesophageal body, of the amplitude (p < 0.02) of primary peristaltic contraction waves. In conclusion prolonged intraoesophageal acidification can considerably affect frequency of deglutition, morphology, and propagating patterns of primary peristaltic contractions. This study shows that these effects are independent from volume distension of the oesophagus and supports the presence of acid sensitive receptors in the oesophageal mucosa.

Assessment of neural inhibition of the lower esophageal sphincter in cats with esophagitis

BACKGROUND

The aim of this study was to investigate the inhibitory innervation of the lower esophageal sphincter in the presence of esophagitis.

METHODS

Esophagitis was produced in five anesthetized cats with intraesophageal perfusion of HCl. Sphincter pressure responses were assessed with a sleeve catheter after administration of bethanechol, cholecystokinin octapeptide, and McNeil-A343 and with intraesophageal balloon distension.

RESULTS

In the presence of esophagitis (1) resting lower esophageal sphincter pressure decreased; (2) the excitatory response to bethanechol was maintained; (3) there was a reduction in the excitatory response to McNeil-A343 and cholecystokinin at the highest dosages; (4) there was an increase in the potency of cholecystokinin and McNeil-A343 to produce an inhibitory response; (5) the inhibitory response to intraesophageal balloon distension was maintained; and (6) increased inhibitory responses took longer to normalize than the reduced excitatory responses.

CONCLUSIONS

Esophagitis decreases cholinergic excitation, but neural inhibition to the LES remains intact. These findings suggest that blocking intact inhibition may be a new therapeutic approach for esophagitis caused by gastroesophageal reflux.

Gastroesophageal pH step-up inaccurately locates proximal border of lower esophageal sphincter

Limiting the widespread use of 24-hr pH monitoring is the necessity of manometrically placing the pH probe 5 cm above the proximal lower esophageal sphincter (LES) border. Therefore, we prospectively compared LES localization by gastroesophageal pH step-up with manometry in 71 patients and 14 asymptomatic volunteers. The gastroesophageal pH step-up significantly correlated with the proximal LES border in patients (r = 0.53, P less than 0.0001) and volunteers (r = 0.91, P less than 0.0001). Based on previously published criteria, the pH step-up value was considered acceptably accurate if it was within +/- 3 cm (6 cm total span) of the manometrically determined proximal LES border. In 58% of patients and 29% of volunteers the pH step-up occurred outside this accuracy range. Esophagitis (P = 0.015) and abnormal reflux parameters (P = 0.002) were variables contributing to this error. Subsequent analysis found that the pH step-up overestimated the proximal LES border and occurred at the midportion of the sphincter. The pH step-up still inaccurately located the mid LES in 34% of patients. Therefore, manometry should remain the standard for accurate LES localization prior to placing the pH probe.

Effects of atropine and glycopyrrolate on esophageal, gastric, and tracheal pH in anesthetized dogs

Atropine, glycopyrrolate, or saline solution was administered before anesthesia in a blinded, controlled study of 40 dogs scheduled to undergo surgery. Effects of treatment on esophageal, gastric, and tracheal pH were measured with an intraluminal pH meter. Preanesthetic administration of atropine and glycopyrrolate had no effect on esophageal, gastric, or tracheal pH but did result in increased heart rate. Thoracotomy procedures resulted in decreased intraluminal esophageal pH and increased heart rate. Esophageal pH at the level of the thoracic inlet decreased over the duration of surgery.

Pathophysiology of gastroesophageal reflux

The factors controlling competence of the gastroesophageal junction have been carefully analyzed over the last decade. Although the presence of an anatomic sphincter guarding the lower esophagus has not been confirmed in humans, a manometrically defined high-pressure zone is present in the lower esophagus. The magnitude of sphincter pressure correlates well with the incidence of pathologic gastroesophageal reflux. Another important determinant of cardial competence is the length of intra-abdominal esophagus. The interaction of length and pressure in maintaining competence is demonstrated by several clinical and experimental studies. Twenty percent of refluxors have normal components of cardial competence. Several physical factors, namely components of Laplace's law, may govern control of reflux especially after antireflux repairs. The occurrence of esophagitis as a complication of gastroesophageal reflux is determined by the ability of the esophageal body to rid itself of an acid load as well as by factors that delay gastric emptying.

Determinants of gastro-oesophageal reflux and their inter-relationships

Gastro-oesophageal reflux was measured by 24-h ambulatory oesophageal pH monitoring in 220 patients with symptoms suggestive of gastro-oesophageal reflux disease. By multiple regression analysis it was found that the pressure in the distal oesophageal high pressure zone, the presence of a hiatal hernia, the intra-abdominal length of the high pressure zone, the amplitude of the contraction waves in the distal oesophagus and age all significantly participated in the determination of the amount of gastro-oesophageal reflux. The pressure in the distal oesophageal high pressure zone was the single variable that correlated most strongly to the amount of reflux. Although the amount of reflux increased significantly with increasing weight as measured by Broca's index, this variable did not participate in the determination of reflux by the multiple regression test. The study emphasizes the role of the pressure and intra-abdominal length of the distal oesophageal high pressure zone as the primary antireflux barrier. It also shows that a hiatal hernia plays a role in generating gastro-oesophageal reflux through a mechanism other than affecting the pressure and the intra-abdominal length of the high pressure zone.

Is an antireflux procedure necessary in conjunction with parietal cell vagotomy in the absence of preoperative reflux?

During a 4 year period, we found no objective evidence that parietal cell vagotomy contributes to the production of gastroesophageal reflux. The fact that patients without reflux preoperatively achieved the same satisfactory clinical results whether parietal cell vagotomy was or was not accompanied by an antireflux procedure supports this view. Therefore, in the absence of reflux, we cannot recommend the prophylactic use of an antireflux procedure in combination with parietal cell vagotomy in the treatment of patients with duodenal ulcer. On the other hand, patients with duodenal ulcer should be evaluated for gastroesophageal reflux before operation because it is desirable to combine parietal cell vagotomy with an antireflux procedure if both conditions exist. Patients who have mild reflux preoperatively but no symptoms of reflux after parietal cell vagotomy alone, as in three of the four patients in Group IV, may have such symptoms subsequently. Therefore, we think that the combined procedure does not increase the morbidity over that of parietal cell vagotomy alone and recommend the combination of parietal cell vagotomy and an antireflux procedure for any patient undergoing operation for duodenal ulcer who also demonstrates an abnormal degree of gastroesophageal reflux.

Length of the distal esophageal sphincter and competency of the cardia

Pressure and abdominal length of the distal esophageal sphincter are important factors in maintaining competency of the cardia against challenges of intraabdominal pressure. Some patients with normal distal esophageal sphincter pressure and position may have reflux which could be due to the inability of the cardia to overcome challenges of intragastric pressure. Three experimental studies and one clinical study were designed to evaluate this problem. The results showed that the resistance to flow through the cardia is related to the integrated effect of distal esophageal sphincter pressure and length; the ratio of distal esophageal sphincter to intragastric pressure necessary to maintain competency is inversely related to the length of sphincter present; gastric dilatation has an adverse effect on the degree of competency achieved by a given distal esophageal sphincter length; and patients with an overall distal esophageal sphincter length of 2 cm or less measured at rest in the fasting state are subject to reflux caused by gastric dilatation, increased intragastric pressure independent of intraabdominal pressure, or both.

The defense mechanisms of the esophagus

Gastroesophageal reflux is a normal event, and the gastrointestinal tract possesses mechanisms to deal with the refluxed content so that symptoms are not produced. When the amount of refluxed material increases, or the quality changes, or one or more of the defense mechanisms breaks down, then the consequences occur in the esophagus. The variability of symptoms, of mucosal changes, and of motility patterns in response to pathologic gastroesophageal reflux imposes difficulties when one is trying to assess this disorder objectively.

Evaluation and management of diseases of the esophagus

Current methods to evaluate patients with esophageal disease include barium swallow with fluoroscopy, which is useful in demonstrating structural defects. Disordered motility is better evaluated with a cine-esophagram. Recent application of radioisotopes has been useful in evaluation of esophageal reflux and the post-treatment of achalasia. Esophageal motility studies may evaluate lower esophageal sphincter and upper esophageal sphincter pressures and the response of the body of the esophagus to series of swallows. Since there is no "gold standard" for the evaluation of reflux esophagitis, some of the tests designed to evaluate reflux and the patient's reaction to acid in the esophagus include the acid infusion test, the standard acid reflux test, the acid clearance test, and 24-hour pH monitoring. Endoscopy with either the flexible or the rigid instrument is important for the diagnosis of obstruction or esophagitis and allows direct visualization of the esophagus. The treatment of reflux esophagitis is discussed. The differential diagnosis of dysphagia may include achalasia, diffuse esophageal spasm, and mechanical obstruction of the esophagus due to rings, webs, strictures, and benign or malignant tumors. The evaluation of dysphagia should include radiologic as well as endoscopic evaluation. Treatment of obstruction varies according to the nature of the lesion. The Mallory-Weiss syndrome or bleeding from the mucosal tears of the gastroesophageal junction and Boerhaave's syndrome, spontaneous esophageal perforation, are two disorders associated with vomiting. The Mallory-Weiss syndrome usually resolves without specific therapy, but a high index of suspicion is required for patients with chest pain after vomiting, as spontaneous perforation necessitates immediate surgery. Most diverticula need no treatment, but the Zenker diverticulum, if symptomatic, should probably be surgically repaired.

Gastric secretion and emptying of liquids in reflex esophagitis

We have investigated the gastric secretory activity and the emptying half-time of a liquid meal in 17 selected patients with reflex esophagitis compared to 10 controls. The basal acid output and the basal and maximal secretory volume were higher in the patient group (P less than 0.05, P = 0.05, and P less than 0.01, respectively), while the maximal acid output and the basal and maximal acid concentration were not different in the two groups. The gastric emptying half-time of a liquid meal was higher in the patient group (P less than 0.001). Our results show that gastric function may be altered in reflux esophagitis patients and suggest particularly that a delayed emptying of liquids may play a role in the pathogenesis of the disease in some patients.

Evaluation of elevation of the head of the bed, bethanechol, and antacid form tablets on gastroesophageal reflux

To ascertain how elevation of the head of the bed, bethanechol, and antacid foam tablets affect gastroesophageal reflux, we used prolonged intraesophageal pH monitoring in 55 symptomatic patients. Acid exposure was separated into reflux frequency and esophageal acid clearance time and recorded during the day in the upright posture and recumbent at night. Values before and during each therapy were compared to physiologic reflux in 15 asymptomatic controls. Ten patients slept with the head of the bed elevated and had a 67% improvement in the acid clearance time (P less than 0.025); however, the frequency of reflux episodes remained unchanged. Twelve patients given 25 mg of bethanechol 4 times a day had a 50% decrease in recumbent acid exposure only (P less than 0.05), due to a trend towards decreased reflux episodes and acid clearance in time. Bethanechol combined with head of bed elevation in 19 other patients decreased both reflux frequency (30%) and acid clearance time (53%, all P less than 0.05). Antacid foam tablets failed to significantly diminish acid exposure. Nocturnal reflux responded the best to those therapies tested.

Manometric oesophageal function, acid perfusion test and symptomatology in a 55-year-old general population

The frequency of different kinds of oesophageal dysfunction (OD) as shown by manometry and acid perfusion test was investigated in a 55-year-old general population. OD was found in 34 +/- 8% (95% confidence interval). Seventeen per cent had signs of dysmotility, 14% of hiatal hernia, 6% of lower oesophageal sphincter (LES) hypotension, 5% had a positive acid perfusion test and 13% had more than one kind of OD. Symptoms of gastro-oesophageal reflux and chest symptoms were significantly more common in OD subjects than in subjects with normal oesophageal function. The oesophageal function tests had a capability in detecting 66% of subjects in the general population with heartburn or acid regurgitation, whereas they had a poor capability in detecting subjects with other oesophageal related symptoms. This investigation can therefore not answer the question whether our criteria for OD is clinically relevant or not. Irrespective of this, it is important to know the frequency of OD in the general population if the relevance of the OD frequency in hospital patient materials is to be evaluated.

Lower esophageal sphincter pressure in histologic esophagitis

The fasting lower esophageal sphincter pressure of 18 normal volunteers was compared to 22 patients with symptoms and objective evidence of gastroesophageal reflux. Lower esophageal sphincter pressure was measured by rapid pull-through using an 8-lumen radially perfused catheter that sampled pressure every45 degrees around the circumference of the sphincter. The 22 reflux patients were subdivided for analysis into two groups, those with an acute inflammatory infiltrate on biopsy and those without inflammation. Those patients without inflammatory esophagitis had normal sphincter pressures. Those with a definite inflammatory infiltrate had pressures significantly less than normal. The least reliable separation between normals and those with inflammatory esophagitis occurred in the anterior orientations. We conclude that while basal lower esophageal sphincter pressure measurement may identify patients with reflux and inflammatory esophagitis, it is of no help in identifying those patients with reflux unassociated with inflammation. Decreased basal fasting LESP does not appear to be the most important primary determinant of gastroesophageal reflux.

Pulmonary aspiration as a consequence of gastroesophageal reflux: a diagnostic approach

A radioisotope scintiscanning technique that can document pulmonary aspiration of gastric contents in patients with gastroesophageal reflux is described. Six patients with suspected nocturnal aspiration from reflux were studied. Three of the six had positive lung scans 8 hr after intragastric placement of 10 mCi of technetium 99m sulfur colloid. Overnight intraesophageal pH monitoring revealed prolonged episodes of GE reflux in those with positive scans. These preliminary observations suggest that this scintigraphic technique may be an effective method for documenting pulmonary symptoms as a consequence of gastroesophageal reflux.

Clinical and in vitro analysis of determinants of gastroesophageal competence. A study of the principles of antireflux surgery

The analysis of esophageal manometry and 24 hour esophageal pH monitoring in 266 consecutive patients indicates that the competency of the cardia depends upon the amplitude of the distal esophageal high pressure zone and the length of the abdominal esophagus. These two determinants of competency were examined using human esophagi in a unique in vitro model which allowed control of these parameters, as well as intraabdominal, intragastric, and intrathoracic pressures. The following principles of the function of the abdominal esophagus were graphically illustrated: (1) Competency of a segment of intraabdominal esophagus without intrinsic tone occurs only when intraabdominal pressure is equal to or greater than intragastric pressure. (2) Competency of a segment of intraabdominal esophagus without intrinsic tone is directly related to its length. (3) The length of intraabdominal esophagus necessary to maintain competency is indirectly related to variations in intraabdominal pressure. (4) Competency of a segment of intraabdominal esophagus is augmented by the presence of intrinsic tone, and the shorter the length, the greater the intrinsic tone needed. (5) Competency of a segment of intraabdominal esophagus is augmented by negative intrathoracic pressure. These findings beautifully illustrate the mechanical valvelike function of the abdominal esophagus and the objectives to be accomplished in the surgical treatment of gastroesophageal reflux.

Esophageal epithelial response to gastroesophageal reflux. A quantitative study

Exposure of the distal esophageal mucosa to acid gastric juice was quantitated by 24-hr pH monitoring in 100 individuals and was correlated with morphologic data derived from esophageal biopsies. The degree of acid exposure to the distal esophagus correlated directly with increases in both relative and absolute length of the subepithelial papillae and to relative basal zone hyperplasia. Both papillary length and basal zone hyperplasia decreased after antireflux surgery had reduced acid exposure to normal. Reflux in the recumbent position resulted in prolonged exposure of the mucosa to acid because of poor acid clearing from the esophagus. This caused longer papillae than did upright reflux, where there were more frequent reflux episodes, but with rapid acid clearance. The presence of a hiatal hernia was associated with longer papillae, lower DES pressure, increased reflux frequency, and prolonged recumbent acid clearance. Twenty-four hour pH monitoring correlated better with papillary length than did symptoms or other clinical measures of gastroesophageal reflux.

Relationship between gastro-oesophageal acid reflux, basal gastro-oesophageal sphincter pressure, and gastric acid secretion

Twelve-hour continuous pH-recording at the distal end of the oesophagus and measurement of basal gastro-oesophageal sphincter pressure with perfused catheters were carried out in 108 subjects. Fasting gastric secretion, basal secretion, and maximal acid secretion after subcutaneous injection of 6 microgram pentagastrin/kg bodyweight were determined additionally in some of the subjects. There was a significant inverse correlation between the results of continuous pH-recording and basal gastro-oesophageal sphincter pressure, which confirms the relationship between low sphincter pressure and gastro-oesophageal acid reflux. Furthermore, there was a significant direct correlation between the results of continuous pH-recording and the volume of basal secretion and the basal acid output. These findings emphasize the significance of gastric acid secretion for the results of continuous pH-recording. As reflux-preventive surgery may elicit alterations in the variables of acid secretion, the results of continuous pH-recording do not allow conclusions to be drawn with regard to the effectiveness of a surgically established gastro-oesophageal barrier.

Esophageal reflux--an unrecognized cause of recurrent obstructive bronchitis in children

Forty-three children with recurrent obstructive bronchitis but without prominent gastrointestinal symptoms were studied for esophageal reflux roentgenographically and by manometry. Roentgenographic evidence for reflux was shown in 26; these patients had a mean lower esophageal sphincter pressure of 6.3 mm Hg as compared to a mean LES pressure of 21.9 mm Hg in normal control infants. The remaining 17 patients had a mean LES pressure of 10.0 mm Hg, also significantly lower than that of control subjects. Fifteen of 20 patients with recurrent obstructive bronchitis noted alleviation of their pulmonary symptoms after medical treatment of their reflux. Sequential studies of another group with radiologically demonstrated reflux showed increases in sphincter pressures and disappearance of radiologically observed reflux in one third of the patients. It is suggested that esophageal reflux should be sought in patients with recurrent bronchitis: if found, antireflux therapy might be expected to improve the pulmonary symptomatology.

The effects of premedication drugs on the lower oesophageal high pressure zone and reflux status of rhesus monkeys and man

Thirty-five human volunteers and eight Rhesus monkeys were studied with standard gastrooesophageal manometric techniqes and their reflux status was evaluated witha pH probe placed in the lower oesophagus. morphine sulphate, pethidine hydrochloride, or idazepam was given intravenously until drowsiness was induced. The manometric and pH studies were repeated. All three drugs decreased the lower oesophageal high pressure zone and increased the probability of relux in both monkeys and man. Thes findings are relevant in the preparation of patients for surgery since gastrooesophageal reflux and pulmonary aspiration may be a problen in the pre-and postoperative phases.

Evaluation of the Nissen antireflux procedure by esophageal manometry and twenty-four hour pH monitoring

Fifteen normal volunteers without symptoms of gastroesophageal reflux and sixteen patients with symptoms of gastroesophageal reflux unresponsive to medical management and having endoscopic esophagitis had esophageal manometry and twenty-four hour pH monitoring of the distal esophagus. The symptomatic patients underwent a Nissen antireflux procedure and were restudied at four months. After surgery, patients had less reflux, a higher sphincteric pressure, and an equal amount of sphincter within the abdomen as did asymptomatic control subjects.