THE NORMAL HUMAN ESOPHAGEAL MUCOSA: A HISTOLOGICAL REAPPRAISAL

Transcription

1 GASTROENTEROLOGY 68:40-44, 1975 Copyright 1975 by The Williams & Wilkins Co. Vol. 68, No.1 Printed in U.S.A. THE NORMAL HUMAN ESOPHAGEAL MUCOSA: A HISTOLOGICAL REAPPRAISAL WILFRED M. WEINSTEIN, M.D., EARL R. BOGOCH, AND KENNETH L. BOWES, M.D. Departments of Medicine and Surgery, University of Alberta, Edmonton, Alberta, Canada In 19 asymptomatic subjects, a total of 95 mucosal suction biopsies were taken from multiple sites in the distal 10 cm of esophagus. The biopsies were examined for evidence of basal cell hyperplasia and elongated dermal papillae, features considered to be histological consequences of gastroesophageal reflux. Fifty-seven per cent of the biopsies in the distal 2.5 cm of the esophagus and 19% of the biopsies above 2.5 cm exhibited these histological features. It is generally accepted that a poor correlation exists between symptoms of gastroesophageal reflux and inflammatory change in the esophageal mucosa. l 2 In 1970, Ismail-Beigi et al. 3 described new histological features in the esophageal mucosa that they considered to be consequences of gastroesophageal reflux. Their study was based on the examination of biopsies taken at a single, manometrically localized site in the lower esophagus. Eight-five per cent of their symptomatic patients with a positive ph test had biopsies exhibiting basal cell hyperplasia and Received December 10, Accepted July 8, Presented in part at the annual meeting of the Canadian Gastroenterological Association, Edmonton, Alberta, Canada, January, Address requests for reprints to: Dr. W. M. Weinstein, Department of Medicine, Clinical Sciences Building, University of Alberta, Edmonton, Alberta, Canada, T6G 2G3. Supported by Research Grant MA4246 from the Medical Research Council of Canada. Mr. Bogoch was supported by a student research grant from the Medical Research Council of Canada (MS-1129). The authors wish to thank the volunteers in the study, and also Bill Saunders for his advice and assistance, Diane Soltesz and Colleen Murdoch for their technical assistance, Dr. C. E. Pope II for reviewing some of the biopsies, and Dr. E. E. Daniel for several critical reviews of the manuscript. 40 elongated dermal papillae. On the other hand, 90% of their asymptomatic patients with a negative ph test had mucosa with only a thin basal zone, and shallow dermal papillae. However, they had two sizeable subgroups of patients: asymptomatic with a positive ph test, and symptomatic with a negative ph test. In both of these subgroups, more than 50% of the individuals had biopsies exhibiting the changes of basal cell hyperplasia and elongated dermal papillae. What is the reliability of these histological criteria in a clinical diagnostic setting? Their value as a diagnostic aid would be enhanced if it were shown that there is good diagnostic reliability in biopsies taken at random from the lower esophagus, without manometric localization. For this reason, we examined biopsies taken from multiple sites in normal volunteers, and applied the histological criteria described by Ismail-Beigi et al. 3 Materials and Methods Nineteen individuals without symptoms of gastroesophageal reflux gave informed consent for the studies. Thirteen of the 19 had never experienced the sensation of heartburn. The remaining 6 had experienced the sensation on rare occasions in the past. The 19 individuals ranged in age from 18 to 47 years (mean, 24). Fourteen of the 19 subjects were less than 25 years of age. Twelve of the 19 subjects were

2 January 1975 HISTOLOGY OF NORMAL ESOPHAGEAL MUCOSA 41 females and 5 were on oral contraceptives. None of the 19 subjects were on other medications, none had any other symptoms, and none had previously undergone upper gastrointestinal tract surgery. An acid infusion test, esophageal manometry study, and multiple biopsies of the esophagus were performed in each subject. A modified Bernstein acid infusion test' was performed as follows : a polyvinyl tube was introduced into the esophagus to a distance of 25 cm from the incisors. An infusion of normal saline at 120 drops per min was started for 10 min. Then the infusion was changed to 0.1 N HCI without the subject's knowledge, and it was continued at the same rate for 30 min. If retrosternal burning occurred during the infusion of acid, saline was reinstituted without the subject's knowledge. The test was interpreted as positive if the subject experienced a sensation of retrosternal burning at any time during the infusion of HC!. Four water-filled polyvinyl catheters (0.044 cm internal diameter, outside diameter) were used to transmit intraluminal pressures to external transducers (P23De, Statham Instruments Inc., Oxnard, Calif.). The outputs from the transducers were recorded on a Honeywell (Denver, Colo.) Visicorder. The catheters were constructed so that there were four infusion ports, 5 cm apart. Distilled water was infused through each catheter at a rate of 1.8 ml per min. The subjects were in the supine position during the manometry studies. Resting intraluminal pressures were recorded distal to within, and proximal to the lower esophageal sphincter (LES). An average of three pressure readings was taken as the final value for LES pressures. The LES pressure was also recorded during abdominal compression using a large cuff inflated to 50 mm Hg. The LES was considered manometrically normal if: (1) the resting pressure within the LES was equal to or greater than 10 cm of water relative to intragastric readings, and, (2) the sphincter-stomach gradient was maintained or increased during abdominal compression. 5 Esophageal mucosal biopsies were obtained at least 10 days after the acid infusion test and manometry studies. A hydraulic biopsy tubes was modified with the attachment of two polyvinyl manometry catheters (0.044 cm internal diameter, cm outside diameter) to opposite sides of the hydraulic biopsy tube (fig. 1). The infusion ports of both manometry catheters were 2 cm proximal to the biopsy port of the hydraulic biopsy tube. One manometry catheter was in direct line with the biopsy port of the hydraulic biopsy tube, and the second manome- FIG. 1. Diagrammatic representation of the hydraulic biopsy tube with two manometry catheters attached. try catheter was opposite. Distilled water was infused through both catheters at 1.8 ml per min. The hydraulic biopsy tube was inserted into the stomach, and the other end of the tube was attached to a notched stand, allowing removal at precise 0.5-cm intervals. Serial biopsies were then obtained, beginning just below the LES and continuing for a distance of up to 10 cm into the esophagus. A total of 95 biopsies were obtained from the 19 subjects. The mucosal biopsies were oriented on monofilament plastic mesh, fixed for 12 to 24 hr in Bouin's solution, embedded in paraffin, and serially sectioned at Ninety consecutive sections from the best oriented core of the biopsy were evaluated by two of us (W.M.W. and E.R.B.). The histological criteria previously outlined by Ismail-Beigi et a!. were used. A biopsy was read as "abnormal" if it contained: (1) a hyperplastic basal cell layer, and (2) dermal papillae extending two-thirds or more of the thickness of the epithelial layer (fig. 2). In cases of disagreement between the two observers the biopsies were reevaluated in the coded slides until there was agreement. Results The results are outlined in table 1. Two of the 19 subjects had a positive acid infusion test. Both of these subjects had normal manometry studies. One of the 2 subjects had never previously experienced the sensation of heartburn. Three of the 19 subjects had an abnormal manometry study. One of these 3 had a low resting sphincter pressure of 6 cm of water. The remaining 2 had normal resting sphincter pressures, but had inadequate responses to abdominal compression. The two manometry tubes attached to the hydraulic biopsy tube usually recorded entry into the LES at different levels. The average distance between these two levels was 1.7 ± 0.7 (so) cm. In some subjects, the catheter on the same side as the biopsy

3 42 WEINSTEIN ET AL. Vol. 68, No.1,-...., ~..... ~.... ~. ~ I...!. J ~....,.. \'. ~ ~.: # " ~!'- "to '. ",... - ti.,. t: ti _ FIG. 2. Top, esophageal mucosal biopsy specimen representative of those graded as "normal" in this study. Note the darkly staining basal cell layer (B), and the height of the dermal papilla (P) (hematoxylin and eosin, x 175). Bottom, esophageal mucosal biopsy specimen representative of those graded as "abnormal" in this study. Note the hyperplastic darkly staining basal cell layer and the elongated dermal papillae (P), compared to the biopsy above (hematoxylin and eosin, x 175). port recorded entry into sphincter first, and in other subjects, it was the opposite catheter which recorded entry first. The site of transition from gastric columnar to squamous epithelium was always at, or just above [0.7 ± 0.5 (sn) em], the point where both catheters recorded entry into sphincter. The distal margin of the LES was defined manometrically as the point at which the second of the two catheters recorded entry into the LES. We found that several "firings" of the

4 January 1975 HISTOLOGY OF NORMAL ESOPHAGEAL MUCOSA 43 TABLE 1. Results of an acid infusion test, esophageal manometry studies, and mucosal biopsies in 19 asymptomatic subjects Subject Age Sex LES pressure cmh,o Acid infusion No. of No. of biopsies abnormal taken biopsies Sites of normal biopsies a Sites of abnormal biopsies a 1" 22 F 20" Neg 6 2 1, 2.5, 4.5, , 1.5 2" 22 M 15 Neg F 11 Neg , 3.5, M 12 Neg 3 None 2,3, F 19 Neg 5 3 6,10 0.5,1, F 12 Neg 3 None 4,7, M 18 Neg , 1.5, 2, 4, 8 8 b 28 M 16 Neg ,0.5,1,2 9 b 33 M 12 Pos 6 4 3, 7 1.5,2,5, F 40 Neg , 0.5, 1, F 14 Neg 6 4 5, 10 1, 1.5, 2, b 22 M 13' Neg F 25 Neg ,2.5,3,5,7, F 47 Neg , 1,3,5,7, F 21 Neg , 2, 2.5, M 10 Neg 5 1 0,5,7, F 20 Pos 6 None 0, 0.5, 1, 2, 4, 8 18 b 23 F 6 Neg 6 None 1.5, 2, 2.5, 3.5, 5.5, F 10 Neg 9 None 5, 1, 1.5, 3, 3.5, 5.5, 7.5,9.5, 10 a Centimeters above the distal margin of the lower esophageal sphincter (LES); zero represents the distal margin of the LES. h Rare previous heartburn., Inadequate response to abdominal compression. hydraulic biopsy tube were often necessary in order to obtain a single esophageal mucosal biopsy at any given site. In two individuals, we were only able to obtain one biopsy despite numerous attempts at multiple sites. We had the impression that this was due, in part, to the presence of thick mucus in the esophagus. Six subjects noted a mild retrosternal discomfort with swallowing for 24 hr after the biopsies were taken. There were no other symptoms or complications from the biopsy procedure. In each subject at least two gastric biopsies were obtained before the first esophageal (squamous) biopsy was obtained. In no subject did a gastric biopsy follow the first sq uamous epithelial biopsy. Seven biopsies from 5 subjects contained both gastric columnar and squamous epithelium. Four of these seven junctional biopsies contained enough squamous epithelium to permit interpretation. There was no evidence of acute inflammation in any of the biopsies. The two observers agreed on the biopsy interpretation in 89% of the biopsies in the first evaluation and in the remainder of the biopsies in the second evaluation. Fourteen of the 19 subjects had one or more abnormal biopsies, and 7 of the 19 had three or more abnormal biopsies. The proportion of abnormal biopsies was no different in the group of 6 who had experienced heartburn on rare previous occa SlOns. A total of 36 of the 95 biopsies obtained in the study were abnormal, and the majority of these were concentrated in the most distal esophagus. In the distal 2.5 cm of esophagus, 27 of 47 biopsies (57%) were abnormal. However, proximal to this 2.5-cm region, nine of 48 biopsies (19%) were abnormal. As mentioned previously, 5 of the 19 subjects had either a positive acid infusion test or an abnormal manometry study. In these 5 subjects, seven of 25 (28%) biopsies were abnormal, whereas 29 of 70 (41%) biopsies were abnormal in the 14 subjects

5 44 WEINSTEIN ET AL. Vol. 68, No.1 who had both a normal acid infusion test and manometry study. Discussion The most significant finding in this study was that 57% of the biopsies obtained from the distal 2.5 cm of esophagus in asymptomatic individuals exhibited the features of basal cell hyperplasia and elongated dermal papillae. Even above this 2.5-cm region, 19% of the biopsies exhibited these changes. If one assumes that elongated dermal papillae and basal cell hyperplasia do represent histological consequences of reflux, then our findings would suggest that the most distal histological esophagus is frequently bathed in gastric' contents. Perhaps these histological changes result from the minor degrees of "physiologic reflux" that may occur whenever the lower esophageal sphincter relaxes in response to a swallow. Were our results prejudiced by the fact that some of our subjects had "significant" asymptomatic reflux? This is extremely unlikely in view of their age, lack of symptoms, and the manometry study results. Furthermore, the proportion of abnormal biopsies was not increased in the 5 subjects who had either a positive acid infusion test or an abnormal manometry study. Nevertheless, the question of significant asymptomatic reflux is difficult to define with currently available techniques. Some of the reasons for this difficulty have been analyzed recently. 7 The finding that the two manometry catheters attached to the hydraulic biopsy tube recorded entry into the distal margin of the LES at different levels has been reported previously.8 This may be due, in part, to the oblique entry of the esophagus into the stomach. We did find a close correlation, however, between the level of the histological transition and the level at which the second manometry catheter first recorded entry into the.distal margin of the LES. One objective of our study was to help establish the diagnostic reliability of the histological lesion described by Ismail Beigi et al. 3 To do this, it is necessary to compare our data with theirs. From our study it is clear that the new histological criteria cannot be applied in biopsies taken from the most distal esophagus. In asymptomatic individuals, more than one-half the biopsies were abnormal in the distal 2.5 cm of esophagus. However, even above this region, 19% of the biopsies were abnormal. Ismail-Beigi et al. 3 studied 43 patients who had severe heartburn and other symptoms of esophagitis. Ten of their 43 patients had a normal ph test. 3 They expressed their biopsy results in subgroups based on the results of this single ph test. However, if one analyzes their biopsy results in the 43 patients with severe heartburn taken as a group (irrespective of ph test results), it is evident that only 69% of the 86 biopsies were abnormal. We think that the histological criteria in question are unlikely to be of significant diagnostic value in a clinical setting when one or two biopsies are taken, even above the most distal 2.5 cm of esophagus. REFERENCES 1. Siegel CI, Hendrix TR: Esophageal abnormalities induced by acid perfusion in patients with heartburn. J Clin Invest 42: , Goldman MS, Rasch JR, Wiltsie DS, et al: The incidence of esophagitis in peptic ulcer disease. Am J Dig Dis 12: , Ismail-Beigi F, Horton PF, Pope CE II: Histological consequences of gastroesophageal reflux in man. Gastroenterology 58: , Bernstein LM, Baker LA: A clinical test for esophagitis. Gastroenterology 34: , Cohen S, Harris LD: Does hiatus hernia affect competence of the gastroesophageal sphincter? N Engl J Med 284: , Flick AL, Quinton WE, Rubin CE: A peroral hydraulic biopsy tube for multiple sampling at any level of the gastrointestinal tract. Gastroenterology 40: , Winans CS: Testing the normal gastroesophageal junction. Gastroenterology 62: , Kaye MD, Showalter JP: Manometric configuration of the lower esophageal sphincter in normal human subjects. Gastroenterology 61: , 1971