Chapter 30 (page 148)

The Pyloric Sphincteric Cylinder in Health and Disease

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Chapter 30 (page 148)

Chapter 30

Duodenal Ulceration and the Pyloric Sphincteric Cylinder

As far as we are aware the contractile behaviour of the pyloric sphincteric cylinder in cases of duodenal ulceration has not been described. However, other features of the pyloric part of the stomach in duodenal ulceration have been studied extensively, and a consideration of some of these may give an indication of the type of motility which can be expected.

Griffith et al. (l966) examined the rate of gastric emptying in a small number of cases of uncomplicated duodenal ulceration by means of radio-isotope labelled solid meals, and found it to be faster than normal. Buckler (l967), in a study of 193 patients with uncomplicated duodenal ulcer, found no significant difference in the total emptying time of a solid meal as compared with normal subjects, and concluded that the pattern of gastric emptying in duodenal ulcer patients was similar to that of normal individuals.

Schrager et al. (l967) performed histological examinations of the "antrum" in 75 surgical resection specimens of duodenal ulceration. In a third of the cases the duodenal ulcer was adjacent to the pyloric mucosa, and in the remainder it was 2.0 cm distal to the "sphincter". The duodenal mucosa surrounding the ulcer was normal. In all cases mild, diffuse inflammatory alterations, involving the whole of the antral mucosa, were noted; these consisted of lymphocytic and plasma cell infiltration, with variable degrees of pyloric gland destruction and intestinalization. In the great majority of cases less than 25 percent of pyloric glands were damaged; in a small minority there was a 25 to 50 percent reduction in glands, and in some of these an increase in fibrous tissue in the submucosa was observed. The changes were more severe along the lesser curvature near the boundary zone between the "antral" and body mucosa, i.e. the part furthest removed from the ulcer; the body mucosa appeared completely normal. It was concluded that duodenal ulceration was associated with mild inflammatory change of the gastric antral mucosa, in contrast to gastric ulceration, which was accompanied by much more severe inflammatory alterations.

Griffith et al. (l968), in a second series of cases, again found the gastric emptying rate of solids to be more rapid in duodenal ulceration than in normal controls, while George (l968) found that the mean emptying time of a fluid test-meal in 34 patients with uncomplicated duodenal ulcer did not differ from that of controls.

Kwong et al. (l970) studied the electrical activity of the distal 6.0 cm of the "antrum" by means of serosal electrodes implanted at operation for duodenal ulceration. The general patterns of the wave forms, the amplitude of the waves and the conduction time of the electrical impulses were the same as in normal controls. However, the frequency of the waves was increased, being approximately 6 cycles per minute in duodenal ulcer as opposed to 3 cycles per minute in controls. Cobb et al. (l97l), in a study of 12 duodenal ulcer patients and normal controls, found no difference in the pattern of gastric emptying of liquids in the two groups.

Fordtran and Walsh (l973) studied gastric emptying of solid meals in 7 patients with duodenal ulcer and 6 normal subjects. Using an infusion of sodiumbicarbonate to control intragastric pH and to act as a buffer, it was found that the duodenal ulcer patients emptied the meal buffer at a much more rapid rate than normal controls. It was acknowledged that the emptying rate of the buffer might not necessarily be the same as the emptying rate of the total mass in the stomach.

Using a solid meal labelled with Indium ^113m DPTA, Howlett et al. (l976) compared gastric emptying in 27 duodenal ulcer patients with 26 normal subjects. The half emptying time did not differ significantly in the two groups; when applying a method of principal component analysis to the results, a number of duodenal ulcer patients showed a relative slowing of the rate during the later phase of gastric emptying. It was suggested that the faster emptying previously found by Griffith et al. (l966, l968) and by Fordtran and Walsh (l973) might have been due to the fact that their meals had twice the volume of that of Howlett et al. (l976).

Liebermann-Meffert et al. (l98l) studied the response of gastric musculature to electrical vagal stimulation during intraoperative vagomotor tests in different groups of patients. Although a pressure rise occurred in all groups, it was found that the amplitude and duration of the contractions, and the integrated motor response was significantly greater in patients with gastric ulcer than in patients with duodenal ulcer. It was concluded that the motility disorder of the gastric musculature in duodenal ulceration was less evident than in gastric ulceration and seemed to be of minor importance. During histological studies of the antropyloric wall in peptic ulcer disease, Liebermann-Meffert and Allgöwer (l98l) found that less thickening occurred in duodenal ulcer than in gastric ulcer; the abnormal features of muscle and ganglion cells were also less severe in duodenal ulceration.

Lam et al. (l982), using a marker-dilution method, found that duodenal ulcer patients emptied liquid meals more rapidly than normal subjects.

Earlam et al. (l985) found histological evidence of chronic "antral" gastritis in 33 of 36 patients with duodenal ulceration who required surgery after prolonged but unsuccessful medical therapy. Of these, 24 had chronic superficial, and 9 chronic atrophic gastritis. The high incidence of antral gastritis was considered to be a striking finding; it was thought that it could be related to the severe symptoms in this particular group of cases.

According to Brooks (l985) duodenal ulceration should be looked upon as a heterogeneous syndrome which includes the following: (1) acute erosions; (2) uncomplicated ulcers; (3) bleeding; (4) perforation; (5) gastric outlet obstruction; (6) ulcers resistant to healing under treatment, and (7) recurrent ulceration after surgery. Not all patients will exhibit the same abnormalities in function; in some, gastric motor function may show an increase in frequency and amplitude of "antral" contractions with accelerated emptying of solids. On the whole associated gastritis of antral mucosa is a common finding.