MACKAY : POST-GASTRECTOMY MALABSORPTION 767

THE EFFECT OF JEJUNAL SEGMENT INTERPOSITION ON POST-GASTRECTOMY MALABSORPTION IN DOGS

BY COLIN MACKAY DEPARTMENT OF SURGERY, WESTERN INFIRMARY, GLASGOW

ALTHOUGH Polya gastrectomy is now less popular as a method of treating duodenal ulcer, it has been widely used in the past. There is, therefore, in the community a large number of patients who have had gastrectomy. While the majority of these patients are very well, a minority have troublesome symptoms and of these a small percentage will require remedial surgery. Henley (1952) was the first to describe jejunal segment interposition as a remedial operation; since then the procedure has been fairly widely used (Hedenstedt and Heijkenskjold, 1961; Kay and Cox,

lsoperistaltic gastro- duodenal loop f IPGO)

Antiperistaltic gastro- jejunal loop fAPGJ I Antiperistaltic gastro-

duodenal loop f A P G O ) FIG. I.-The four groups.

1964; Herrington, 1965). However, there have been few metabolic studies and the actual mechanisms of any benefit produced are not clear.

The aim of the present project was to study, in dogs, the effect of jejunal segment interposition on :-

a. Post-gastrectomy malabsorption. b. Gastric emptying. It was decided to limit the study to malabsorption

because of the difficulty in obtaining objective measurements in conditions such as dumping and bilious vomiting in the experimental animal.

METHODS AND MATERIALS Sixteen mongrel dogs weighing 12-27 kg. were

subjected to a Polya-type gastrectomy. The proximal limit of resection was a line joining the point on the lesser curve where the left gastric artery met the 53*

stomach wall and, on the greater curve, the highest short gastric artery, thus producing a 75-80 per cent resection. Postoperatively the dogs, with their aggressive eating habits, tended to vomit and were accordingly fed at hourly intervals during the day with as much food as they could tolerate without vomiting. Three months following gastrectomy the dogs were again weighed.

They were then randomly allocated to one of four groups (Fig. I). Group I with Polya gastrectomy alone acted as controls. In Group 2 an isoperistaltic

(per cent)

- 10

-20 F - months after I’ gastrectomy

, 3 months after - I loop

P<O.Ol FIG. 2.--Changes in weight (mean . \ t andud error) for the four

groups. (:hange in weight 3 months after gastrectomy IS expressed as a percentage of pre-gastrectomy weight. Change in weight afrcr jejunal interposition is expressed as a percentage of pre-inter- pusition weight. P values ohtained using Student’s r-test.

segment of jejunum was interposed between the gastric remnant and the duodenum. In Group 3 an antiperistaltic segment was interposed in a similar way. Group 4, with an antiperistaltic segment interposed between the gastric remnant and the jejunum, differed from the other two interposition groups in that the food by-passed the duodenum. An attempt was made to produce a segment about 7 cm. long, but the length varied slightly depending on the available blood-supply. Postoperatively the dogs were again fed ad libitum at hourly intervals during the day. Three months after the second operation the dogs were again weighed. A fifth group consisted of 4 normal dogs.

Each animal was placed in a metabolic cage for a period of 5 days and fed a daily diet of 350 g. of the same proprietary dog food. The animals were allowed z days to become accustomed to their surroundings and faeces were collected over the

768 BRIT. J. SURG., 1969, Vol. 56, No. 10, OCTOBER

final 3 days for analysis of fat by the method of van de Kamer, Huinink, and Weyers (1949) and of nitrogen by the method of Kjeldahl as described by Prunty, McSwiney, and Hawkins (1959).

B and that on serial films measured as a percentage of this initial size. Thus a graphic representation of the rate of gastric emptying was obtained in each animal.

Conventional tests of xylose absorption were performed, but the results were extremely variable owing mainly to difficulty in obtaining accurate collec- tions of urine. The conventional test was therefore abandoned. Xylose (7 g.) was given orally and

P <0.005 P<0.005 P<O.Ol P<O.O5 FIG. 3.-Daily faecal fat output (mean +standard error) for each

of five groups. The Polya gastrectomy group was the basis for comparison.

P<O.OI P>0.05 P<0.05 P>O.I FIG. 4.-Daily faecal nitrogen output (mean +standard error)

for each of five groups. The Polya gastrectomy group was the basis for comparison.

FIG. 5.-Typical radiographs. A, A dog with a Polya gastrectomy; 6, A dog with gastrectomy plus an isoperistalric gastroduodenal segment; C, A dog with gastrectomy plus an anti- peristaltic gastrojejunal segment. Radiographs on the left were taken within 5 mnutes of ingestion of the meal; those on the right were taken 2 hours after the meal.

Gastric emptying was measured radiologically on each animal. After a 12-hour fast, the dog was fed a 50-8. meal of a proprietary dog food to which was added a solution of z tablespoonfuls of Micropaque in IOO ml. water. The volume of this meal was similar to rhe bulk of an average hourly feed; the dogs finished the meal within z minutes. Radiographs samples of blood were withdrawn at hourly intervals were taken immediately after the meal and at half- for 6 hours for estimation of the concentration of hourly intervals for z hours. The size of the gastric xylose in the plasma by the method of Roe and Rice remnant on each radiograph was measured by (1948). T o provide a more physiological stimulus to planimetry. The gastric size in the film exposed the gastric remnant the xylose was given in the immediately after the meal was taken as IOO per cent form of a meal. The animals were starved for

MACKAY: POST-GASTRECTOMY MALABSORPTION 769

12 hours and then given a meal of 50 g. proprietary dog food to which was added a solution of 7 g. xylose dissolved in IOO ml. warm water. The food completely absorbed the fluid. The animals finished the meal within 2 minutes. Thereafter blood was withdrawn for estimation of plasma-xylose concentra- tion at hourly intervals for 6 hours. Because inter- group differences were most marked during the first 2 hours, the test was repeated and samples of blood were taken every 15 minutes over the first 2 hours.

x----x Normal x x Gastrectomy - IPGD X-X APGD *-. APGJ

I I I+ 2

Time after meal (hours)

FIG. 6.-Mean rate of gastric emptying. Abbreviations as shown in Fig. I.

501 I , T

0 - I 1; 2 Hours

FIG. 8.-I'lasma-xylose curves in gastrectomy and isoperistaltic gastroduodenal groups following xylose meal.

RESULTS Body-weight.-Three months following gastrec-

tomy all animals had lost weight (Fig. 2). In the following 3 months (i.e., after jejunal interposition) there was significant weight gain in all three inter- position groups,, but in the group with gastrectomy alone the animals continued to lose weight although not as much as in the first 3 months. Most weight was gained in the isoperistaltic gastroduodenal group.

Faecal Fat.--The daily faecal fat outputs are shown in Fig. 3. The daily excretion of fat in the faeces was significantly higher in the dogs which had undergone Polya gastrectomy than in the group of normal dogs. In all three jejunal interposition groups the daily faecal fat was significantly lower than in the gastrectomy group, the difference being more marked in the gastroduodenal groups than in the gastrojejunal.

Faecal Nitrogen.-The faecal excretion of nitrogen was significantly higher in the gastrectomy group than in the group of normal dogs (Fig. 4). In all three jejunal interposition groups the faecal nitrogen was lower than in the gastrectomy group, the difference being significant in the antiperistaltic gastroduodenal group, almost significant in the isoperistaltic gastroduodenal group, and not signifi- cant in the antiperistaltic gastrojejunal group.

35

5 - E

e L 25

0

a

2 - : x 15 x E 3 - a

5

x----x Normal x............~ Gastrectomy - IPGD x-x APGD 0-0 APGJ

x-. --. X z - 4

I I 2 3 4 5 6

Hours FIG. 7.-Mean plasma-xylose curves following ingestion of 7 g.

xylose in water.

50-

2

% 30-

x

0 2 1 I + Hours

FIG. 9.--Plasma-xylose curves in gastrectomy and antiperistaltic gastroduodenal groups following xylose meal.

Radiology.-Fig. 5 A-C are representative radio- graphs from three of the five groups. In the gastrec- tomy group the radio-opaque material started to leave the gastric remnant within 5 minutes and at 2 hours there was no evidence of material in the remnant. In the isoperistaltic gastroduodenal group there was still an appreciable amount of radio-opaque material in the gastric remnant 2 hours after the meal. Also in the antiperistaltic gastrojejunal group the gastric remnant was still visible 2 hours after the meal, although the amount of retained material was not as great as in the isoperistaltic gastroduodenal group. The mean rates of gastric emptying for each of the five groups are shown in Fig. 6. In normal dogs gastric emptying was slow over the first hour but more rapid thereafter, being complete by 2 hours. In the gastrectomy group gastric emptying was very

770 BRIT. J. SURG., 1969, Vol. 56, No. 10, OCTOBER

rapid over the first 30 minutes. A very different picture was obtained in the jejunal interposition groups. There was delay in gastric emptying which was more marked in the gastroduodenal groups than in the gastrojejunal. There was little to choose between the isoperistaltic and antiperistaltic gastroduodenal groups.

Xylose Test.-When xylose was given alone there was little or no difference in the plasma-xylose curves

0 I I+ 2 * Hours

FIG. 10.-Plasma-xylose curves in gastrectomy and antiperistaltic gastrojejunal groups following xylose meal.

possible ways in which jejunal interposition may benefit. Firstly, rerouting the food through the duodenum; this is the well-known principle under- lying the practice of converting a Polya gastrectomy to a Billroth-I. This cannot be the only way in which the animals benefited because those with antiperi- staltic gastrojejunal segments also gained weight and had less steatorrhoea than the dogs with gastrectomy. The second possible way benefit is obtained is delay in gastric emptying with restoration of reservoir function to the gastric remnant.

Measurement of the rate of gastric emptying is difficult. The methods available tend to be either accurate and unphysiological or inaccurate and physio- logical. The radiological method used in this work employed relatively physiological substances, although it cannot be claimed to be highly accurate as it measures a three-dimensional structure in only two dimensions. The results, however, demonstrated a clear-cut delay in the rate of emptying of the gastric remnant in the dogs with the interposed segments, a finding contrary to that of Everson (I~ss), who con- cluded that interposed jejunal segments merely acted as simple conduits between the gastric remnant and the duodenum.

It was hoped that the modification of the xylose absorption test would also give an assessment of the rate of gastric emptying. When xylose was given orally along with a small amount of water there was

FIG. I 1.-Mechanism of interposition of an isoperistaltic gastroduodenal segment.

between the groups (Fig. 7), suggesting that there was no difference in the pattern of xylose absorption. However, when xylose was given incorporated in a meal a very different picture was obtained; the peak plasma-xylose level was reached in I hour in the gastrectomy group, in 2 hours in the antiperistaltic gastrojejunal group, between z and 3 hours in the isoperistaltic gastroduodenal group, and at 3 hours in the antiperistaltic gastroduodenal group. The inter-group differences were most marked over the first 2 hours of the test and these are shown in

DISCUSSION This work confirms the well-documented finding

that high Polya gastrectomy results in weight-loss and steatorrhoea (Stammers and Williams, 1963). The interposition of a segment of jejunum between the gastric remnant and the small bowel has been shown in dogs to result in significant gain in weight and reduction of steatorrhoea in keeping with the findings of Everson (1955) and Little (1967). There are two

Figs. 8-10.

no difference in the plasma-xylose curves between the groups. However, when the xylose was given along with a meal marked differences among the groups were revealed. In the gastrectomy group the plasma-xylose concentration increased rapidly suggesting rapid gastric emptying; in the gastro- duodenal groups the increase was much more gradual, suggesting delay in gastric emptying; in the gastro- jejunal group the increase was more rapid than in the gastroduodenal groups suggesting less delay in gastric emptying. This method of investigating gastric emptying is being further investigated both in dogs and in patients.

The demonstrated delay in gastric emptying could result from one or both of two factors: an inhibitory mechanism in the duodenum and an intrinsic property of the interposed segment itself. In con- nexion with the latter it might be suggested that the delay in gastric emptying was due to a mechanical narrowing at the anastomosis; this is unlikely as the method of jejunal interposition used did not interfere with the Polya anastomosis (Fig. I I).

ORR: SINGLE-LAYER INTESTINAL ANASTOMOSIS 77 1

Acknowledgements.-I wish to acknowledge the shown to confer any advantage over an isoperistaltic help and guidance of Professor A. W. Kay and segment. However, further work is required to Mr. I. E. Gillespie, and also the technical assistance at determine the optimum length of the interposed the Wellcome Surgical Research Institute, Garscube, segment. and the Department of Surgery, Western Infirmary

Glasgow. SUMMARY

The use of an antiperistaltic segment has not been

Sixteen mongrel dogs were subjected to Polya gastrectomy. Three months later they were randomly allocated to one of the following four groups: (I) gastrectomy alone; (2) gastrectomy plus isoperistaltic gastroduodenal segment; (3) gastrectomy plus anti- peristaltic gastroduodenal segment; and (4) gastrec- tomy plus antiperistaltic gastrojejunal segment. Metabolic studies and measurement of gastric emptying were performed on these animals and also on 4 normal dogs. Gastrectomy resulted in weight- loss and steatorrhoea. Jejunal segment interposition resulted in significant weight-gain, reduced output of fat and nitrogen in the faeces, and delay in gastric emptying. Gastroduodenal segments were more effective than gastrojejunal; antiperistaltic segments did not appear to have much advantage over iso- peristaltic segments.

REFERENCES EVERSON, T. C . (Ig55), Archs Surg., Chicago, 70, 865. HEDENSTEDT, S., and HEIJKENSKJOLD, F. (1961), Acta chir.

HENLEY, F. A. (1952), Br .3 . Surg., 40, 118. HERRINGTON, J. L. (1969 , Ann. Surg., 162, 789. KAY, A. W., and COX, A. G. (1964), Br .3 . Surg., 51, 763. LITTLE, J. M. (1967), Ibid., 54, 958. PRUNTY, F. T. G., MCSWINEY, R. R., and HAWKINS, J. B.

(1959), A Laboratory Manual of Chemical Pathology. London : Pergamon.

ROE, J. H., and RICE, E. W. (1948), 3. biol. Chem., 173, 507.

STAMMERS, F. A. R., and WILLIAMS, J. A. (1963), Partial Gastrectomy : Complications and Metabolic Consequences. London : Butterworths.

VAN DE KAMER, J. H., HUININK, H. TEN B., and WEYERS, H. A. (Ig49),3. biol. Chem., 177, 347.

scand., 121, 262.

A SINGLE-LAYER INTESTINAL ANASTOMOSIS BY N. W. M. ORR

DEPARTMENT OF SURGERY, ST. THOMAS’S HOSPITAL, LONDON

THE aim of an intestinal anastomosis is to make a row of stitches (Beling, 1957; Buchin and van sound join of bowel through which the contents will Geertruyden, 1960; Heifetz, 1966; Bronwell, pass as soon as possible. Initially the anastomosis Rutledge, and Dalton, 1967; Hamilton, 1967). These should be secure, watertight, and haemostatic. The studies have shown that the two-layer inverting stitch amount of tissue trauma inflicted while making the is associated with a high incidence of leakage, anastomosis will affect the eventual strength of the obstruction of the lumen, formation of adhesions,

- - A 5 mm. B 2mm.

FIG. 1.-Types of intestinal anastomosis. A, Standard; B, One-layer.

join and the rate at which normal bowel function returns.

Halsted (1887) considered that only one row of sutures should be necessary to make an anastomosis and regarded Q second row as a factor of danger rather than of security. A number of clinical and experimental studies have been published in which anastomoses made with two rows of inverting stitches have been compared to anastomoses made with one 53**

clinical morbidity, and delayed intestinal motility. There seems to be little clinical or experimental support for the two-layer inverting stitch in living tissue. Yet most surgeons still use it as their standard technique.

ANIMAL STUDIES Methods.-Thirty-six anastomoses have been

made in the small intestines of 11 greyhounds.