Pharyngoesophageal (Zenker's) diverticulum: A reappraisal

Pharyngoesophageal (Zenker's) diverticulum: A reappraisal

GASTROENTEROLOGY 1982:82:734-6 Pharyngoesopha geal (Zenker Diverticulum: A Reappraisal THOMAS E. KNUFF, STANLEY B. BENJAMIN, and DONALD 0. CASTELL G...

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GASTROENTEROLOGY

1982:82:734-6

Pharyngoesopha geal (Zenker Diverticulum: A Reappraisal THOMAS E. KNUFF, STANLEY B. BENJAMIN, and DONALD 0. CASTELL Gastroenterology Branch, Internal Medicine Service, National Naval Medical Center, and the Digestive Diseases Division, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland

Manometric evaluation of pharyngeal contraction and upper esophageal sphincter relaxation was performed in a group of patients with Zenker’s diverticulum using a specially designed low compliance manometric recording system. The results were compared with those in normal controls. In all cases, the upper esophageal sphincter showed complete relaxation during swallowing and no incoordination between pharyngeal contraction and upper esophageal sphincter relaxation could be demonstrated compared to time intervals found in the control group. Resting upper esophageal sphincter pressures were significantly lower in diverticulum patients than in controls. It is concluded that symptomatic patients with Zenker’s diverticulum have normal pharyngeal-upper esophageal sphincter coordination, exhibit complete upper esophageal sphincter relaxation on swallowing, and have low resting upper esophageal sphincter pressures. These results seriously question the previous concept of abnormalities of pharyngeal-upper

dination

in patients

esophageal

sphincter

coor-

with Zenker’s diverticulum.

A pharyngoesophageal diverticulum (PED) is a protrusion of the hypopharyngeal mucosa posteriorly between the oblique fibers of the inferior pharyngeal Received June 22, 1981. Accepted December 3, 1981. Address requests for reprints to: Donald 0. Castell, Digestive Diseases Division, Uniformed Services University Health Sciences, Bethesda, Maryland 20814.

M.D., of the

This work was supported by the Department of the Navy Clinical Investigation Project #O-06-1398 and the Uniformed Services University of the Health Sciences Grant #R08316. Presented at the Annual Meeting of the American Gastroenterological Association, Salt Lake City, Utah, May 1980 and published in abstract form in GASTROENTEROLOGY 1980;78:1196. The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Navy or the Depart-

ment of Defense. 0 1982 by the American

Gastroenterological

0016.5085/82/040734-03$02.50

Association

constrictor and the transverse fibers of the cricopharyngeus muscle. Since the first case reported by Ludlow in 1769 (l), numerous etiologic mechanisms for PED have been proposed. The majority of these theories postulate disordered function between pharyngeal contraction and cricopharyngeal relaxation. At present, the most widely accepted hypothesis is that of muscular incoordination during swallowing with the cricopharyngeus undergoing premature closure before the entire pharyngeal bolus can be propelled into the esophagus (2). However, the evidence that such a physiologic abnormality exists remains controversial (3,4). We have studied the manometric relationship between pharyngeal contraction and upper esophageal sphincter (UES) relaxation in patients with symptomatic PED and compared the result with similar measurements in healthy controls. Methods Our study group included 9 patients, 5 men and 4 women, in their sixth and seventh decades, with a mean age of 60 yr. A PED, varying in size from 0.5 to 12 cm, had been previously diagnosed in each patient by barium swallow. All were located in a left lateral direction. The control group was composed of 15 patients in a similar age group who had no evidence of upper esophageal disease.

Manometric

Studies

A 4-lumen polyvinyl oval catheter (internal diameter of each lumen 0.8 mm; catheter diameter 3.2 x 4.5 mm), which had been previously shown to conform to the shape of the UES (5), was utilized. The orifices for recording were radially oriented at 90” angles, and spaced at 5-cm intervals. This catheter shape and orientation enabled recording of UES pressures in the posterior, anterior, and right and left lateral directions (6). A pneumohydraulit capillary infusion system (Arndorfer Medical Specialties) infused distilled water at a rate of 0.5 mlimin,

April

1982

ZENKER’S

DIVERTICIJLUM

735

maximal resting sphincter pressure toward esophageal pressure induced by a swallow. To critically assess the timing of pressure events between pharyngeal contraction and UES relaxation and in order to quantitate this relationship, we assessed four parameters (Figure 1).

A’ is the time from onset of UES relaxation

0

Figure

2

.4

.6

.a

1.0 2 A TIME ,sec>

.s

.B

2.0

1. Comparison of time intervals for pharyngeal contraction and cricopharyngeal relaxation in controls and patients with pharyngoesophageal diverticulum (PED). Details of intervals described in text.

providing a high fidelity, low compliance system with a pressure rise rate of >4OO mmHg/s (7). The catheters were connected to transducers and then to a direct writing recorder.

Study

Using these four parameters, timing of any other specific internal event could be extrapolated. For each patient, a mean value of each of these parameters for the nine swallows was obtained for comparison. Tracings were analyzed in a blinded fashion at the same sitting by mixing and random coding to allow all tracings to be read as unknowns. Statistical evaluation of mean values between patients and controls for all indices measured was made using a t-test for unpaired samples.

Results

Design

All patients were studied after at least an 8-h fast and after stopping all medications for at least 24 h. The catheter was passed through the nose and studies were performed in a supine position. A manometric profile of the LJES was performed utilizing a station pull-through technique at 0.5-cm intervals. At the point of maximal UES pressure in each direction (posterior, anterior, right, and left), the patient was instructed to swallow on three separate occasions. Speed of the recording paper was increased to 5 mm/s during these swallows to allow for more accurate measurement of pressure events. Pharyngeal pressures were simultaneously recorded 5 cm proximally during studies in the anterior, right, and left lateral positions, and these nine swallows were used for analysis of pressure events. Analysis

to the onset of pharyngeal contraction. B’ is the time from onset of UES relaxation to peak pharyngeal contraction. relaxation to termiC’ is the time from onset of sphincter nation of pharyngeal contraction. D’ establishes the duration of UES relaxation.

of Recordings

A schematic representation of normal pharyngeal and UES pressure events is shown in Figure 1. During voluntary swallowing, the UES relaxation begins before pharyngeal contraction (point A); the nadir of UES relaxation occurs before the zenith of pharyngeal contractions (point B); the pharyngeal contractions return to baseline [point C) during the recovery of sphincter relaxation; and the UES pressure returns to baseline levels [point D) after pharyngeal contraction has been terminated. The postrelaxation rise in UES pressure represents cricopharyngeal contraction as part of the peristaltic wave passing from pharynx into the esophagus. Resting UES pressures in each of the four directions were measured as the gradient between maximal resting pressure in the upper esophagus just below the UES and maximal stable sphincter pressure before a swallow. Relaxation of the UES was defined as a sharp decrease in

In all patients and controls, UES relaxation occurred with each swallow. These were qualitatively evaluated to be complete relaxations, decreasing to the level of the esophageal resting pressure in all events. A comparison of mean values for the four parameters of pharyngeal contraction and UES relaxation between our PED patients and controls revealed no differences between the two groups (Figure 1). These parameters included the interval from onset of UES relaxation to the onset of pharyngeal contraction (A’], the time from the onset of UES relaxation to the peak of pharyngeal pressure (B’), the interval from the onset of UES relaxation to the termination of pharyngeal contraction (C’), and total duration of UES relaxation (D’). These are listed in Table 1 and shown in Figure 1. In evaluating the UES resting pressures alone, however, a marked difference was noted. Mean UES pressures recorded in the four axial directions beTable

I.

Comparison of Mean Values for the Four Parameters of Pharyngeal Contraction and Upper Esophageal Sphincter Relaxation between Pharyngoesophageal Diverticulum Patients and Controls PED patients

A’ B’ C’ D’

(x 2 SE, s)

Controls (5f + SE, s)

0.54 0.94 1.23 1.44

0.58 0.98 1.26 1.58

2 -+ 2 +

0.08 0.12 0.13 0.15

k t k k

0.05 0.06 0.07 0.07

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GASTROENTEROLOGY Vol. 82. No. 4

KNUFF ET AL.

Table

2.

Mean Upper Esophageal for Pharyngoesophageal Patients and Controls

Sphincter Pressures Diverticiulum

UES pressure PED patients Posterior Left lateral Anterior Right lateral

61.6 26.9 41.6 41.7

z! ? ? 2

11.2 5.6 8.3 6.0

(x f SE, mmHg) Controls 91.6 42.9 72.2 41.9

-1-8.4 -t 5.3 -t 6.1 * 8.1

0 POSTERIOR P
Figure

LEFT P< 0.05

ANTERlOR P
2. Comparison of resting pressures in the cricopharyngeus in four orientations for normals and patients with pharyngoesophageal diverticulum (PED).

tween our PED patients and controls is seen in Figure 2. The mean pressures recorded in the posterior, left lateral, and anterior locations in PED patients were significantly lower than those for controls (p < 0.05). These are listed in Table 2.

Discussion The mechanism of swallowing is an integrated precision performance requiring coordinated relaxation of the UES in the face of high caudal propulsive pharyngeal pressures which propel a bolus of food from the pharynx through the hypopharynx and into the proximal esophagus. Since a PED is a relatively constant anatomic mucosal protrusion between the constricting inferior pharyngeal muscle mass and the relaxing mass of the circopharyngeus, teleologic presumptions as to etiology are only natural. This has led to such explanations as cricopharyngeal achalasia, delayed cricopharyngeal opening, a second swallow hypothesis, and mechanical incoordination of pressure events. While previous manometric studies on PED patients have been attempted, results have been controversial. In this study, we have utilized modern manometric techniques not previously available, including a low compliance infusion system and an oval-shaped catheter, to record pharyngeal activity and UES resting pressures and relaxation in PED patients. Similar to previous reports, we have found no increased pressure (“spasm”) or poor relaxation (“achalasia”) of the UES; however, unlike prior repdrts, we have been unable to disclose any evidence of pharyngeal-UES incoordination. In all instances in our PED patients and in the controls, the onset of LIES relaxation preceded pharyngeal con-

traction, the UES consistently relaxed to esophageal baseline, and pharyngeal contraction had been terminated before the return of UES pressure to resting values. The presence of these phenomena fail to document the previously proposed etiologies of PED. Using the manometric technique described in this study, specific quantitation of the radial asymmetry of the UES could be appreciated. While low UES pressures in patients with PED have been reported in the past (21, those findings have been controversial (8). Our results have confirmed the presence of low resting UES pressures in PED patients; however, it is unclear whether this might be a cause or effect. We conclude that symptomatic patients with PED have decreased resting UES pressures, normal UES relaxation, and exhibit no manometric evidence of pharyngeal-UES incoordination. While we have not clarified the etiology of PED, it is our contention that these results seriously question the previous concepts of the role of pharyngeal-UES contraction abnormalities in the pathophysiology of PED.

References 1. Ludlow A. A case of obstructed

deglutition from a preternatural dilitation of, and bag formed in the pharynx. Medica Observations and Inquiries 1769;3:65-101. 2. Ellis FH, Schlegel IF, Lynch VP, Payne WS. Cricopharyngeal myotomy for pharyngoesophageal diverticulum. Ann Surg 1969;170:340-9.

3. Kodicek J, Creamer B. A study of pharyngeal pouches. J Laryngol Otol 1961;75:406-11. 4. Pedersen SA, Hansen JB, Alstrup P. Pharngo-oesophageal diverticula. Stand J Thorac Cardiovasc Surg 1973;7:87-90. 5. Gerhardt DC, Shuck TS, Bordeaux RA, Winship DH. Human upper esophageal sphincter. Gastroenterology 1978;75:268-74. 6. Winans CS. The pharyngoesophageal closure mechanism: a manometric study. Gastroenterology 1972;63:768-77. 7. Arndorfer RC, Stef JJ, Dodds WJ, et al. Improved infusion system for intraluminal esophageal manometry. Gastroenterology 1977;73:23-7. . 8. Hunt RS, Connell AM, Smiley TB. The cricopharyngeal sphincter in gastric reflux. Gut 1970;11:303.