radiology of the post-operative abdomen

R A D I O L O G Y O F T H E P O S T - O P E R A T I V E A B D O M E N *

ERIC SAMUEL, J. G. DUNCAN, T. PHILP and M. D. SI IMERLING

Department of Diagnostic Radiology, Royal Infirmary, Edinburgh

THE cases which are included in this survey are those with complications occurring in the immediate post-operative period. These are largely related to the pre-operative condition or to the operative procedure. The immediate post-operative period is taken as any time during the normal period of convalescence.

Many of these post-operative patients present with symptoms of some urgency not typical of any specific complication. The form which the treatment takes depends on a quick and accurate assessment of the pathological process, and the radiologist may therefore be called in at a very early stage. Some patients are fit to be transported to the X-ray Department but a number have to be examined in the ward with a bedside unit, which immediately limits the scope of the investigation. With modern resuscitative measures, however, and with the co-operation of the surgical staff, the majority may be examined in the X-ray Department.

The most frequent abdominal complications that are likely to demand the services of the radiologist are : - - 1. Leaks and fistulae _from suture lines. 2. Obstructions and ileus. 3. Infections. 4. Vascular catastrophies and haemorrhages.

These complications may be investigated either by plain films, or by contrast investigations.

PLAIN FILMS OF THE ABDOMEN

In the first instance the radiological investigation is confined to plain radiography of the abdomen in supine, erect and decubitus positions, as the circumstances warrant. The interpretation of these films is modified by the period elapsing after the operation in relation to the disappearance of gas.

Post-operative air in the peritoneal cavity is normally absorbed in four to seven days but may be present up to fourteen days. The presence of gas during the first post-operative week m a y therefore be of limited value, but any obvious increase in the amount of gas during this time is of significance.

The plain film of the abdomen must be scrutinised with special reference to certain points.

Gas patterns in tile bowel. ATter abdominal operative procedures it has always been accepted that a period of so-called " physiological ileus " occurs due to handling and cutting the bowel, but during the last year or two some doubt has been cast on the validity of this conception in the uncomplicated case. Investigation has shown that ileus is not an invariable consequence of abdominal surgery (Baker and Dudley 1961). It may be that excess gas in the uncomplicated case is due to a considerable extent to air swallowing on an empty stomach.

The distribution of gas and fluid levels in the bowel is of importance as occurs in mesenteric thrombosis, acute gastric dilatation, etc., and in relation to the diagnosis of obstruction and ileus. Generalised metabolic disturbances of a non- surgical nature may produce similar appearances and the presence of excess gas and fluid levels therefore need not necessarily indicate obstruction as indicated in the following case.

Figure 1 shows the erect film of a post-operative abdomen in a middle-aged male who developed abdominal distension after repair of an inguinal hernia. Gas and fluid levels are visible but no colicky abdominal pain was complained of and the condition subsided on conservative treatment. The appearance was due to hypopotassaemia which was noted in the post-operative state.

In contrast, in high obstruction there may be a significant absence of gas in dilated bowel loops although some gas may be seen in the stomach. A twenty-year-old male had closure of a perforated duodenal ulcer and vagotomy carried out: three weeks subsequently he developed signs of intestinal obstruction. A significant absence of gas was seen in the upper abdomen. In the erect film a fluid level was seen in the stomach and another lower in the abdomen. A definite diagnosis could not be made from plain films alone. Contrast medium investigation showed an obstructed duodenum between second and third parts.

Residual gas poekets.--Gas may be detected post-operatively in surgical pockets outside the bowel. Such pockets of gas may cause considerable difficulties in differential diagnosis. Figure 2 shows the appearance of an abscess with an air-fluid level

* Based on a symposium presented to the Faculty of Radiologists Meeting in Edinburgh, October 1961

133

134 C L I N I C A L R A D I O L O G Y

FIG. 1 l l ~ J , ~ . - - L I W ~ , t l X L t l t a l t W l ~ I W U ~ , t U t t l y ~ U U W l t l N a t t U l U l ~ V ~ t 111 t l l ~

splenic bed behind the gastric fundus.

FIG. 3 FIG. 4 FIG. 3--Erect film after nephrectomy showing a spherical mass with a fluid level displacing the large bowel. FxG. 4--Lateral

projection of same case showing'extent of mass.

R A D I O L O G Y OF THE P O S T - O P E R A T I V E A B D O M E N 135

Fro. 5 Fic. 6 FIG. 5--Multiple gas bubbles over left half of abdomen i n the retroperitoneal tissues due to retroperitoneal leak from descending

colon. Fro. 6--Mult iple gas bubbles over the right renal area. Perinephric abscess with gas-forming organisms.

developing in the splenic bed after splenectomy for thrombocytopaenic purpura. Figures 3 and 4 show a renal bed abscess occurring after a left nephrectomy. Views taken in different positions show very accurately the extent of the abscess. In the immediate post-operative stage the appearance of fluid levels merely means serous exudate or liquefied blood-- the " gas " being air introduced at operation. This is analagous to the appearances in the thorax after thoracotomy. Thepersis tence of the gas and fluid level beyond a few days usually implies infection with abscess formation.

Extraperitoneal gas.--Spread of gas as a result of infection into the retroperitoneal soft tissues may occur. The interstitial nature of these gas bubbles produces a typical " bubbly " appearance on the films. Figure 5 shows the appearance presented by a retroperitoneal leak from the descending colon with typical gas bubble formation. The film which is reproduced is one of an intravenous urogram series carried out as part of a general investigation. Figure 6 gives a similar appearance on the right side, not, however, produced by a leak from the bowel but by a pyonephrosis with gas-forming organisms in a perinephric abscess--a rare finding.

Soft tissue mass.--This may be detected as a mass by itself or associated with other changes

such as displacement of local organs with local ileus in adjoining coils of bowel. These changes may be accompanied by gas bubbles or fluid levels, both in the mass itself or in adjacent organs.

Gas following instrumentation or diagnostic procedures.--Rupture of the lower oesophagus may be produced during instrumentation for relief of stricture formation or on oesophagoscopy. One such case showed that the oesophagus was split over its lower half and the upper part of the stomach was also involved. Gas may be detected in the biliary tree after sphincterotomy or in the retroperitoneal tissues following barium enema investigation. Gas in the veins of the liver may also be seen in cases of mesenteric thrombosis (Sisk 1961).

CONTRAST I N V E S T I G A T I O N

The plain film of the abdomen may be thus of considerable help in many instances but, particularly during the first few post-operative days, its value may be limited in detection of leaks and high obstructions. Positive contrast media have then to be used to complete the investigation.

Over the past three years, gastrografin has been used extensively in this hospital in both pre- and post-operative states. There are several points worth noting in connection with this subject : - -


FIG. 7 Fro. 8 FIG. 7--Supine film taken one hour after the administration of 40 c.c. gastrografin, showing a large quantity of contrast medium pooled in the gastric fundus. (By courtesy of the Journal of the Royal College of Surgeons of Edinburgh.) FIG. 8~Supine film of same case after the patient had been rotated into the right lateral decubitus position. (By courtesy of the Journal of the Royal

College of Surgeons of Edinburgh.)

1. Gastrografin is a hypertonic solution which mixes readily with fluids in the gastro-intestinal tract.

2. It is not absorbed from the gastro-intestinal tract.

3. It is quite innocuous, and is absorbed if it leaks outside the bowel.

4. Due to its physical properties it can pass through an area of ileus due to any cause. It is thus of value in differentiating between mechanical obstruction and ileus, and the degree and extent of the ileus is demonstrated.

5. Arising out of what has been said, the demon- stration of the onward passage of gastrografin is not proof of the onward passage of bowel content and it is important to appreciate this point. Equally, it must be remembered that incomplete mechanical obstruction may not hold up the passage of gastrografin.

Although in some instances thin barium may be of equal value, or, some may argue, of more value, gastrografin has obvious advantages in cases where leakage, both pre- and post-operatively, is likely to be encountered.

After routine plain films have been taken and examined, 40 c.c. of gastrografin are given, either by mouth or injected through an aspiration tube if this is already in the stomach. The patient is then in the supine or semi-recumbent position. Films

FIG. 9 Lateral film with patient in supine position, showing the stoma lying at a higher level than the dye in the stomach. (By courtesy of the Journal of the Royal College of Surgeons of

Edinburgh.)

are taken at fifteen and thirty minutes but posturing of the patient before radiography is essential for diagnostic purposes. If the patient is allowed to remain supine, the contrast medium will remain pooled in the fundus of the stomach for an indefinite period.

Figures 7, 8 and 9 show contrast studies in a patient who had had a Billroth I gastrectomy carried out. Pooling of contrast medium is seen in the fundus of the stomach after one hour. The patient was then turned on to the right side before further radiography and free flow into the duodenum now takes place. A supine lateral film

R A D I O L O G Y OF T H E P O S T - O P E R A T I V E A B D O M E N

reveals that the stoma lies anteriorly above the level of the contrast medium. Satisfactory positioning is necessary (l) to induce gastric emptying, (2) to demonstrate the stoma both in gastrectomy and gastro-enterostomy by bringing contrast medium into contact with that area, and (3) to induce filling of anastomotic loops and the rest of small bowel if considered necessary.

In some instances the patient may have to be turned into the prone position but any film taken is a guide to further positioning in order to outline the areas in question. Such films may be taken as desired after the thirty minute film. Time must be allowed to allow the contrast medium to seep out through a leak and unless this is done, pathological

A.

137

changes which may be demonstrated clearly later may be easily missed on an early film. Figures 10 and 11 show a Billroth I gastrectomy with a rather poorly demonstrated leak at fifteen minutes but very obvious collection of dye outside the stomach at thirty minutes.

LEAKS A N D FISTULAE In a series of twelve cases with definite post-

operative leaks, eleven anastomotic and one as a result of instrumentation, nine were demonstrated by gastrografin. A further two cases were presumed to have leaked from anastomotic suture lines because of the development of abscesses but none

TABLE 1

POST-OPERATIVE LEAKS AND FISTULAE

Twelve cases: nine demonstrated on gastrografin; three not demonstrated.

Case

1

2

3

4

5

6

7

8

9

10

11

12

Name

D. P.

H, g .

B . G .

E . K .

J . S .

R . W .

R . M .

I . K .

M.L.

K . I .

C. G.

M. H.

i Se

Iv

Iv

Iv

Iv

Iv

Iv

F

Operation (P. G. = Partial Gastrectomy)

P. G. for Ca.

P. G. for D. U.

P. G. for D, U.

P. G. for D. U.

P. G. for G. U.

P. G. for Ca.

P. G. for Ca.

P. G. for G. U.

P. G. for Ca.

Local resection of colon

Local resection of colon

Dilatation of oesophageal stricture

Gastrografin

+

+

+

+

+

+

+

+

Clinical Findings

External fistula

External fistula

Fistula to the pleura

Abscess at anastomosis

External fistula and subphrenic abscess

External fistula and subphrenic abscess

Leaks to the peritoneal cavity

Leak to the peritoneal cavity

P. M.

Disruption of anastomosis

Stomal leak

Operation

Stomal leak

Oesophagus split over lower half

B. Two cases: no leak proved and none demonstrated by gastrografin

Case

1 3 - -

14

Name

R. W.

J. B.

Sex

M

M

Operation

P. G. for D. U.

P. G. for D. U.

Gastrografin Clinical Findings

Subphrenic drained. No leak proved

P. M.

Local peritonitis. No leak demonstrated.

Operation

138 CLINICAL RADIOLOGY

Fro. 10 FIG. 11 Fro. 12 FIG. 10--Fine leak superimposed on gastric fundus from Billroth I gastrectomy suture line demonstrated at fifteen minutes. FIG. 11--Same case after thirty minutes showing much larger collection of contrast medium due to leak. FIG. 12--An extensive

tear of the oesophagus is shown with contrast medium in the mediastinum.

w a s proved at operat ion in one case, or at post- m o r t e m in the other. No leak was demonst ra ted in either of these on gastrografin studies. F o u r of these cases are ment ioned briefly : -

Case 6.--A male, aged fifty-two, who had an oesophago- gastrectomy for a posterior wall gastric ulcer, developed pyrexia three weeks later. Gastrografin examination demonstrated a leak from the anastomosis both into the left subphrenic space and into the left pleural cavity.

Case 5.--A male, aged sixty-one, had a Billroth I gastrectomy carried out for gastric ulceration. Five days after operation, gas was noted to be discharging from the abdominal wound. Gastrografin examination showed a large leak from the anastomotic line passing downwards and to the right of the abdominal wound and upwards to the left below the greater curvature of the stomach. A further pocket was seen above the stoma.

Case 12.--A female, aged thirty-two, developed an extensive lower oesophageal stricture after fairly prolonged intubation for severe duodenal ulcer symptoms during the latter half of pregnancy. Dilatation of the stricture had been carried out on several occasions followed by progressive stenosis. On the last occasion the oesophagus was unfortunately ruptured and a tear was demonstrated from the level of the carina right down through the diaphragm. Gastrografin shows extensive leakage of contrast medium into the mediastinum and demonstrates the extent of the damage to the oesophageal wall. The characteristic appearance of gastrografin in the mediastinal tissues is clearly seen (Fig. 12).

Case 1.--A male, aged seventy-two years, had a Polya gastrectomy carried out for gastric carcinoma. Post- operatively there was pyrexia and upper abdominal pain and guarding. An erect plain film of the abdomen showed two fluid levels under the left dome of the diaphragm with air in the efferent loop. Gas bubbles and a soft tissue mass were seen adjacent to the stoma. Gastrografin defined the gastric stump and a dilated afferent loop and defined the

fluid level outside the stomach. Noleakagewas demonstrated. Post-mortem examination demonstrated a necrotic anastomotic line with leakage.

The other two cases where leaks were missed on gastrografin examinat ion showed leaks at operat ion or pos t -mor tem examinat ion. We have not been able to explain our reason for non- demonstra t ion o f these leaks.

O B S T R U C T I O N S A N D I L E U S

This group is made up of thirteen cases with post-operat ive complicat ions o f obstruct ion or ileus. Of these thirteen cases, nine occurred in gastro-enterostomy recently performed. One other case had been operated on thirty years previously. One case was a retro-colic Polya gastrectomy and two cases had operat ions for colonic pathology.

High intestinal obstruct ions occurring after gastric surgery will present with vomit ing or excessive amounts o f aspirate on gastric suction. There may be no clinical features of note in the early stages apar t f rom this and it is impor tan t to have an early assessment of the situation to decide on the proper line of t reatment .

Plain films of the abdomen may show some distension of the s tomach or gastric remnant but little else. Patients should, i f at all possible, be examined in the X-ray Depa r tmen t where they can be screened, in order to obta in informat ion about abnormal peristalsis, circus movement , etc., and also to posit ion the pat ient for radiography. The examinat ion can be comple ted more quickly by this method than by ward radiography.

/

Case

15

16

17

18

19

20

21

22

23

24

25

2(

27

Name

M.W.

T, C,

J. Mc]

H. E.

W. M

A.M.

J. ~.

E.C.

R.B.

J .T.

G. R.

R .D.

G. R.

Sex

M

M

~. M

M

M

M

M

F

M

M

M

M

M

R A D I O L O G Y OF THE P O S T - O P E R A T I V E ABDOMEN

TABL~ 2 OBSTRUCTIONS AND ILEUS

Ten gastro-enterostomies; one partial gastrectomy; two others.

139

Operation

Gastro-enterostomy for D. U.







Gastro-enterostorny for pyloric stenosis

Gastro-enterostomy thirty years ago

Gastro-enterostomy

Retro-colic partial gastrectomy

Resection of pelvic colon (volvulus)

Laparotomy--mild colitis

X-ray Findings

Obstructed afferent and efferent loops

Circus movement with dilated afferent loop

Circus movement with dilated afferent loop

Obstructed third part of duodenum. No stomal function.

Gastric distension and dilated duodenal loop

Dilated afferent loop. No circus movement. Efferent loop not demonstrated

Stoma not functioning

Dilatation of afferent loop

Circus movement and dilatation of afferent loop

Duodenum dilated at forty minutes. Nil beyond stoma. Gas and fluid levels up to caecum in twenty-four hours

Extrinsic pressure along suture line with deformity and partial obstruction of the efferent loop and obstruction of afferent loop

Grossly dilated jejunum

Jejunal dilatation

Operative Findings

Both loops had herniated through the transverse mesocolon into the lesser sac.

Kink in efferent loop immediately beyond stoma

Proximal inch of afferent loop strangulated by margin of mesocolic gap

Efferent loop adherent to third part of duodenum and, along with mesenteric vessels, causing obstruction. Stoma patent

No operation--settled satisfactorily. Stomal oedema

Afferent loop kinked. Stoma occluded by adhesions and torsion

No operation--settled

No operation--settled

No obstruction. Scarring of jejunum opposite stoma

Settled--no operation

Haematoma of transverse mesocolon with oedema and oedematous omentum around stoma



All the gastro-enterostomies included in Table 2 have been operated on in the past eighteen months and are of the retro-colic type. Case 23 is the one exception. The complications which have been encountered have affected the stoma and either the afferent or efferent loops or a combination of both. As in Case 21, the obstruction may be temporary and caused by oedema at the stoma, or one or both anastomotic loops may herniate into the lesser sac through the mesocolic gap as in Case 15. This patient had a posterior gastro- enterostomy and vagotomy carried out for duodenal ulceration. Eight days post-operatively he

developed colicky abdominal pain. A plain film of the abdomen showed that the stomach was distended with fluid. Gastrografin shows a dilated stomach and proximal duodenal loop. There is a filling defect in the stomach and neither of the anastomotic loops nor the stoma are demonstrated (Fig. 13). The diagnosis was suggested pre- operatively. Both loops had slipped into the lesser sac producing a filling defect on the posterior part of the stomach, obstruction of both loops and proximal dilatation.

In other instances, kinking or obstruction of either loop by the edge of the mesocolon may


occur (Case 16). Case 17 developed strangulation of the proximal inch of the afferent loop by the margin of the mesocolon.

FIG. 13 A distended stomach and proximal duodenal loop

are shown. The antrum of the stomach shows a large filling defect. (By courtesy of the Journal of the

Royal College of Surgeons of Edinburgh.)

Case 18 also had a posterior gastro-enterostomy and vagotomy carried out for duodenal ulceration. Convalescence was satisfactory until the thirteenth post-operative day when the patient began to vomit large amounts of bile-stained fluid and there were also copious aspirates. Gastrografin, after gastric aspiration, shows a rather distended stomach with a dilated duodenal loop up to the mid portion of the third part where there was a complete obstruction (Fig. 14). Very marked to and fro peristalsis was noted. A functioning stoma was not demonstrated. Operation revealed that the efferent loop had become adherent to the third part ,of the duodenum and, along with the mesenteric vessels, was forming a tight band and causing obstruction.

Case 20 was found to have torsion and obstruction of the stoma and kinking of the afferent loop due to adhesions.

Case 23 is of interest although not in the immediate post-operative period. A chronic saddle ulcer had developed opposite the stoma leading to progressive fibrosis and contraction of the jejunum. The jejunal wall had become pulled up into the stoma so that there was no longer direct continuity between afferent and efferent loops and circus movement was taking place.

It is evident from this small group of cases that, although gastro-enterostomy is now being used

Fm. 14 FIG. 15 FIG. 14--Gaseous distension of the stomach and dilatation of the duodenal loop with obstruction in third part. FIG. 15--Extrinsic pressure along the suture line after partial gastrectomy. The efferent loop shows partial, and the afferent loop complete,

obstruction. Haematoma of transverse mesocolon produced pressure deformity.

RADIOLOGY OF THE POST-OPERATIVE ABDOMEN 141

more frequently in preference to partial gastrectolny, complications in the post-operative period are by no means rare. The passage of time and the advent of a newer generation of surgeons have probably helped to cloud the memory regarding the complications which occurred in the past.

The one case of retro-colic Polya gastrectomy in the Table is of interest. Case 25.--This patient, aged fifty-two, was operated on because of a long history of duodenal ulceration. After gastric suction was stopped on the fifth day, he felt distended and vomited 400 c.c. of fluid. Quite large aspirates followed and gastrografin shows a dilated gastric stump and extrinsic pressure along the suture line with deformity and partial obstruction of the efferent loop and obstruction of the afferent loop (Fig. 15). At operation a haematoma was found in the transverse mesocolon producing the pressure deformity seen on the film. There was associated gross oedema of the mesocolon and omentum, the latter being wrapped round the site of the anastomosis.

The two remaining cases in this group presented with mid jejunal obstructions of a " temporary " nature, following laparotomy for colonic pathology. Both of these were demonstrated by contrast examination but settled without operation.

P E R I T O N E A L INFECTIONS A N D SEQUELAE

Peritoneal infection occurring after abdominal operation may arise in one or more of three ways : - -

(a) As a continuation of infection present before the operation.

(b) As a direct result of the operative procedure. (c) As a later complication following wound

infection, haematogenous spread, or direct spread from the bowel content.

Such infections may result in a generalised peritonitis which may progress to local abscess formation, or may be more localised from the outset and remain as a confined intra-abdominal collection of pus.

Although such localised abscesses may occur anywhere within the peritoneal cavity and in certain extra-peritoneal sites, they have a predilection for certain areas of which the subphrenic spaces are the commonest. Of forty-five consecutive cases of post-operative peritoneal infection analysed in the Royal Infirmary, Edinburgh, there were thirty-one cases (69 per cent) oflocalised subphrenic infection with abscess formation.

Ineidenee.--According to Harley (1955), the commonest causes of subphrenic abscess are

perforated peptic ulcers and acute appendicitis. In such cases, the presence of infection before operation must be presumed, but the next commonest cause of such abscesses is abdominal operation itself. Consideration of the type of operation predisposing to peritoneal infection has shown that the highest incidence follows gastric operations, particularly partial gastrectomy. In the present series of forty-five cases under review, it can be seen from Table 3 that gastrectomy accounted for almost half the total incidence of subphrenic abscess. The lower incidence following perforated peptic ulcer and appendicitis might be explained by present-day rigid antibiotic cover in those cases where peritoneal soiling is presumed pre-operatively.

It is now generally accepted that the likeliest cause of peritoneal infection following gastrectomy is the development of a leak from either the anastomotic suture line or the duodenal stump. Depend- ing upon the size and duration of such a leak, it may or may not be demonstrable radiologically by contrast media.

Spread of infeetion.--Pelvic abscesses more commonly follow lower abdominal operations but spread of infection may occur to any part of the intraperitoneal cavity and more central collections of pus between individual coils of small bowel, having no specific anatomical plane, are probably more common than has been realised. Such intraperitoneal spread tends to follow certain recognised pathways of which the paracolic gutters are perhaps the most important (Fig. 16).

Case 28.--C. H., female, aged 12 years. Appendicectomy for acute appendicitis (29.7.61). By 4.8.61 she had developed signs of infection in the right iliac fossa (Fig. 17), and by 9.8.61 a paracolic abscess was showing radiologically,

TABLE 3

FORTY-FIVE CONSECUTIVE CASES OF POST-OPERATIVE

PERITONEAL INFECTION

Operation

Partial gastrectomy

Total gastrectomy

Perforated peptic ulcer

Cholecystectomy

Appendicectomy

Partial colectomy

Others

Total

No. of Cases

17

2

7

5

4

4

6

45

Per cent of Total

t 42

16

11

9

9

13

100


displacing the ascending colon medially (Fig. 18). The pelvic abscess was drained on 17.8.61. She subsequently developed a right suprahepatic abscess and a right empyema, both requiring further drainage (Fig. 19).

Two similar cases were encountered in the present series--one in a young girl of sixteen years following a ruptured right ovarian cyst, and the other in a man of twenty-four years following appendicectomy.

Abscesses following appendicectomy and cholecystectomy tend to occur in the right subphrenic spaces but may spread to the contralateral side (Figs. 25A and 25B). In the case of partial gastrectomy, leakage from the anastomosis will tend to result in left subphrenic infection whereas leakage from the duodenal stump will tend to spread to the right subphrenic area. Harley (1955) observes that partial gastrectomy is the operation most likely to be complicated by subphrenic abscess and that the right and left sides are involved with almost equal frequency. That has also been our finding as is seen from Table 4. It is worthy of note, however,

Right suprahepatic Left suprahepatic

~""~Stom ach and Duodenum

Right infrahepat c ~ j space

. f

Right ~aracolic Left paracolic gutter gutter

Right infracolic Left infracolic _ space space

Pelvis

Fm. 16

TABLE 4 SITE OF ABSCESS FORMATION IN TWENIY CASES

FOLLOWING GASTRECTOMY

Left subphrenic space 7

Right subphrenic space . 6

Localised to area of anastomosis 6

Pelvic 1

that an equal number of abscesses have remained localised to the area of the anastomosis, a feature which does not appear to' have been appreciated before and which suggests that leakage from the suture line is much commoner than leakage from the duodenal stump.

RADIOLOGICAL FEATURES Plain films of abdomen.--The absorption of air

from the peritoneal cavity after laparotomy usually takes about four to seven days but may be delayed longer in certain instances. This will depend to a certain extent on the amount of air present immediately following operation and it has been found that the greatest quantity follows upper abdominal, and particularly gastric, operations. Bevan (1961) considers that localised pneumoperitoneum is more likely to lead to certain complications including the formation of a subphrenic abscess than when the air is more widely dispersed, and advocates free mobility of the patient in the early post-operative period in order to assist the dispersal of the gas. We consider, however, that any undue delay in the absorption of the pneumoperitoneum or any increase in the amount of gas shown radiologically should raise the suspicion of intestinal leakage and peritoneal~infection.

FIG. 17 Fro. 18 FIG. 19 Fro. 17--Case28. Soft tissue mass of abscess in appendix bed (sixth post-operative day). Fro. 18--Case28, Right paracolic abscess displacing colon medially (eleventh post-operative day). FIG. 19--Case 28. Right suprahepatic abscess and right empyema (nine-

teenth post-operative day).

RADIOLOGY OF THE POST-OPERATIVE ABDOMEN 143

Ft6.20 Fm. 21 FIG. 20--Case 29. Large pneumoperitoneum following leak from anastomotic suture line (seventh post-operative day).

FIG. 21--Case 30. Right subphrenic abscess showing thickening of diaphragm (seventh post-operative day).

Case 29.--H. L., male, agedfiftyyears. Partialgastrectomy for duodenal ulcer with repeated haematemeses (17.2.60). Routine films taken on the second post-operative day showed only a very small residual pneumoperitoneum below the right hemidiaphragm. On the seventh post-operative day he was re-examined radiologically and shown to have a large re-accumulation of air within the peritoneal cavity (Fig. 20). Gastrografin failed in this case to show the leak which was present at the upper limit of the suture line and which was closed at laparotomy. He subsequently developed a left subphrenic abscess and a left empyema.

In the absence o f localised infection, the d i aphragm will appear on the erect fi lm as a thin line and generalised in t raper i toneal fluid may occasional ly be seen as a hor izonta l level. Wi th the onset o f subphrenic infection, the shadow of the d i aph ragm thickens and becomes more indis t inct due to in f lammatory exudate. Such changes in the appearances of the d iaphragm and in the a m o u n t of in t raper i tonea l air may occur early in the post- opera t ive per iod and we do no t agree with Bevan (1961) who considers that a plain rad iograph is of little help in the diagnosis o f intest inal leak or subphrenic abscess dur ing the first two weeks after opera t ion .

Case 30.--G. M., male, aged forty-eight years. Polya partial gastrectomy for duodenal ulcer with repeated haematemeses and early obstruction (20.12.60). Within seven days he had developed a right subphrenic abscess and the thickened and indistinct diaphragm is shown in Figure 21. This abscess was drained and leakage from the duodenal stump was found. He subsequently developed a pelvic abscess, the infection having presumably taken the usual route down the paracolic gutter.

The source o f gas in any subphrenic abscess has given rise to considerable controversy. I t may, o f

course, be air remaining fol lowing l apa ro tomy or may be admi t ted th rough the abdomina l wound several days later, especial ly i f wound sepsis and dehiscence supervenes. Anae rob i c organisms are rarely found f rom cul ture of the abscess content and bronchia l fistula is invar iably a very late compl ica t ion. I t appears l ikely tha t the commones t cause is leakage f rom an a b d o m i n a l viscus.

Al though erect or decubi tus films are necessary for the demons t ra t ion of a fluid level in an abscess, the air may be shown on the rout ine supine film which may in fact define bet ter the extent of the abscess and any accessory pockets or tracts.

Case 31.--G. R., male, aged fifty-three years. Polya partial gastrectomy for duodenal ulcer with stenosis (19.5.61). By 28.5.61, i.e., nine days after operation, he had developed a right subphrenic abscess and Figure 22 shows the thick wall of the gas-containing abscess. The cause was considered to be a leaking duodenal stump. Following drainage, his condition improved but a fortnight later he developed a small intestinal obstruction which was confirmed with gastrografin. The supine radiograph of the abdomen showed gas tracking down the right paracolic gutter to the right iliac fossa (Fig. 23).

Cons idera t ion o f the n o r m a l soft tissue landmarks has shown that the ex t ra-per i tonea l fat line may be lost in general ised per i toni t is but , in the case o f localiscd abscesses, will d i sappear only i f an abscess is in the cor respond ing flank (Fr imann- Dah l 1960). Similarly, o ther soft tissue outlines may be b lur red by cont iguous abscesses and the soft tissue opaci ty o f an abscess i tself may be seen before the appearance o f a i r within it, and in fact, air may never appear .


l~lCJ. Zz--t~ase .~ I. lxl~nl, buopnreillC abscess with thick wall (ninth post- Fro. 23 FIG. 24 operative day). Fro. 23--Case 31. Supine film showing air in right paracolic gutter and low small bowel obstruction. FIG. 24--

Case 31. Pelvic abscess as cause of intestinal obstruction,

" A Fro. 25 B Fro. 26

Fro. 25, A and B--Development of left subphrenic abscess, causing bowel displacement and associated wi th intra-thoracic infection. Fro. 26--Abscess in lesser sac associated with retained swab having metal markers.

Returning to the last case, the soft tissue density of a localised pelvic abscess may be seen in the right iliac fossa (Fig. 24). This abscess was lying between coils of ileum and was the cause of the small bowel obstruction. It is of interest to note that the bladder outline is lost due to the adjacent abscess. This sign may be of value in !ocalising abscesses to specific anatomical planes and is of particular value in the pelvis where lateral pro- jections are less satisfactory.

In considering the opacity produced by a localised abscess, attention will naturally be drawn to any displacement and deformity of the normal bowel shadows and to the presence of localised bowel distension. We have already seen how an abscess in the paracolic gutter can displace the colon medially (Fig. 18) and deformity of the caecum is a well-known sign in appendicular abscess (Fig. 17). Figures 25A and 25B show the development of a left

subphrenic abscess following appendicectomy. This is an example of contralateral spread of infection and demonstrates both the soft tissue density of the abscess lying in the left posterior subphrenic space and the downward displacement of the splenic flexure of the colon. In addition to the soft tissue opacity of the abscess and the bowel displacement, the actual cause of the abscess, namely a retained swab, is shown in Figure 26. This abscess is situated within the lesser sac--an uncommon site for a post-operative intraperitoneal abscess, though a case has been reported recently by Elliot, Elliot and Pow (1961).

The occurrence of generalised peritonitis is usually characterised by more widespread ileus, by blurring of normal soft tissue landmarks, and by separation of the distended coils of bowel by peritoneal exudate and effusion. These features are well known and need not be considered further.

R A D I O L O G Y OF T HE P O S T - O P E R A T I V E A B D O M E N 145

The advent of antibiotic therapy has lessened the incidence of generalised spread of peritoneal infection but despite modern therapy, low grade peritoneal inflammation occurs not infrequently with the production of peritoneal adhesions. Sub- acute obstructions may result at a fairly early stage and the risk of obstruction later is always present.

Diaphragm.--Changes in the position and movement of the diaphragm in the presence of subphrenic abscess have been well documented. It is as well to remember, however, that localised or generalised elevation, and restricted or paradoxical movement may not always be present, and con- versely that primary pulmonary atelectasis and infection may produce diaphragmatic signs indis- tinguishable from subphrenic infection. Alterations in the thickness of the diaphragmatic shadow in the presence of intraperitoneal air have already been discussed.

Pulmonary and pleural eomplieations.--A serous pleural effusion is a common finding in association with subphrenic abscess and, as much of this fluid may be in the infi'alobar position, lateral decubitus films are frequently of value. The majority of such effusions resolve after treatment o f the primary infection, but occasionally may progress to empyema and require surgical drainage (Fig. 19).

Pulmonary infection may also occur as a direct extension of subphrenic infection but the development of lung abscesses and broncho-pleural fistula is now rare.

Contrast studies.--During the investigation of left-sided subphrenic abscesses, a small quantity of barium or gastrografin is frequently given to locate the position of the gastric fundus and to show any displacement or deformity of the stomach by such an abscess. Similarly, one may distend the stomach with air though such procedures are valueless in the investigation of abscesses on the right side. Harley (1955) and Frimann-Dahl (1960) both stress the potential dangers of diagnostic pneumoperitoneum in the investigation of subphrenic abscesses.

For the investigation of central or lower abdominal intraperitoneal abscesses, contrast series may show localised displacement of bowel loops around a soft tissue opacity, further aiding the localisation of the lesion.

In addition to localised ileus, mechanical obstruction may supervene due either to the early development of adhesions or to the occlusion of the bowel lumen by the abscess itself (Fig. 24).

The use of gastrografin has proved invaluable for the detection of anastomotic leaks following gastric

operations. Such leaks are now considered to account for one o f the commonest causes of post- operative peritoneal infection.

STUDY OF POST-GASTRECTOMY PATIENTS BY CIN EF LU O RO G RA P H Y

A study was undertaken to assess the usefulness of cinefluorography in the investigation of late post-gastrectomy complications. We were interested to know whether it could complement or even replace conventional methods.

The examination of the gastric remnant and stoma is difficult due to many reasons : - -

1. There is no " n o r m a l " anatomy of the stomach after resection, the appearance of the stomach remnant varying with the type of gastrec - tomy and the individual variations in surgical technique. Equally, the same surgeon doing the same operation will not produce exactly the same contours at the stoma. Detailed notes of the type of operation performed are a pre-requisite before examination of such patients.

2. Over-suturing may leave small mucosal pockets around the cut edges of the stomach and when these are filled with barium it may be extremely difficult to distinguish these from stomal ulcers or ulcers in the gastric remnant.

3. Further distortion may occur at the stoma by the oozing of blood, haematoma formation or the leakage of intestinal contents through the line of anastomosis with the later formation of adhesions and consequent scarring.

4. Recurrent anastomotic ulceration and pene- tration of the ulcer may also lead to secondary fibrosis and distortion during the reparative phase.

5. In the normal stomach, the pyloric sphincter effectively prevents the barium-filled stomach from emptying too rapidly, and the stomach can be examined at leisure. The stoma acts in no such way, and barium passes through the stoma rapidly and the many compression devices invented testify to the difficulty of keeping sufficient barium in the gastric stump for visualisation.

Teehnique.--The technique of our examination consists in asking the patient to swallow one mouthful of barium emulsion in the erect position. A cine run at 8 frames/second is then taken on a 35 ram. Arriflex camera attached to a Siemens 5 inch intensifier. Sixteen mm. copies are made from the 35 ram. Gevapan 30 film for demonstra- tion purposes. The dosage is not excessive as pulsing is employed on our equipment through the G.R. electronic generator. A patient of average weight receives 24 r per minute when 8 frames/ second are exposed (Greening and Proctor).

D(I 6)


FIG. 27A FIG. 28n FIG. 29A FIG. 30A

FIG. 27B FIG. 28B FIG. 29n FIG. 30B FIO. 27, A and B--Polya antecolic partial gastrectomy. Ten days after operation showing obliquity of stoma. Fro. 28, A and B-- Polya partial gastrectomy. Considerable deformity along the lesser curvature and stomal line. FIG. 29, A and B--Polya partial gastrectomy. Stomal ulcer and jejunitis. FIG. 30, A and B--Polya partial gastrectomy. Considerable stasis of afferent loop and

kinking of the elevated efferent loop. The jejunum adjacent to the stoma is enlarged.

Following this cine run, conventional spot films of the stoma may be taken. The patient then swallows more barium to distend the gastric remnant and pressure is maintained on the stoma. The patient is placed in the supine position and the competence of the cardia is tested. Supine and prone films may be taken. Finally, a second cine run may be exposed to show how the fully-filled remnant empties through the stoma.

Attempts were made to establish norms for the various types of partial gastrectomy by studying patients ten days after operation and then re- assessing such cases at the end of six months. The obliquity of the stoma in the antecolic Polya partial gastrectomy has been claimed to be due to post-operative adhesions, particularly between the gastric remnant and the spleen or liver (Stammers 1958). However, on examining the gastric remnant, this obliquity of the stoma may be already present ten days after operation (Fig. 27) and no change in this was seen six months later. It is therefore much more likely that the obliquity is produced by the drag in the erect position due to weight of the loops and their contents on the stoma.

The rate of emptying through the stoma varies enormously but there will be no excessive distension of the afferent and efferent loops in the normal remnant and the jejunal mucosal pattern will be normal.

Suturing deformities.--At the operation it is impossible to produce a completely smooth suture line and, moreover, over-suturing is liable to form pockets. When these pockets are filled with barium it may be extremely difficult to distinguish the features from those of recurrent ulceration (Fig. 28). Oedema in the early stages exaggerates the appearance.

Stomal ulcers.--Several patients with stomal ulcers were examined (Fig. 29). In no case has a stomal ulcer been demonstrated on cinefluorography that could not be visualised by conventional screening and spot films. Cinefluorography showed that when stomal ulceration is present there is a motility disturbance. Over-active movement of the jejunum next to the stoma is frequent and often a see-saw action could be seen between the afferent and efferent loops. The patient who has symptoms and signs suggesting stomal ulceration and who

R A D I O L O G Y OF T HE P O S T - O P E R A T I V E A B D O M E N 147

shows these features of abnonnal motility at the stoma may well have a stomal ulcer, although this may be impossible to demonstrate by barium meal because of oedema and scarring and the ulcer may only be found at operation.

MECHANICAL SYNDROMES 1. Afferent loop abnormality.~ln 1952, Wells and

MacPhee described the afferent loop syndrome. Their patients had persistent vomiting of bile and unmixed food. This is due to kinking of the afferent loop due to several factors and as a result, it becomes distended with secretion. Unfortunately, radiology is not very helpful in this condition. The afferent loop does not fill with barium but this frequent finding is also found with normal gas- trectomies. Neither has intravenous cholangio- graphy, in our experience, helped in the study of this syndrome as suggested by Scott and Whiteside (1956).

In addition to obstruction of the afferent loop, other disturbances may give rise to attacks of vomiting. Not all patients present with vomiting of bile unmixed with food and many patients vomit bile-stained fluid mixed with food. Wells and

MacPhee stated that reflux of barium into the afferent loop has no significance, and this is probably true when reflux is not marked. However, one of our patients who had had frequent attacks of bilious vomiting and epigastric pain since the Polya operation nine years before showed gross distension and abnormal motility of the afferent loop (Fig. 30). In this patient the afferent loop is directly below the stoma and filling of this loop took place rapidly with the production of excessive motility. The efferent loop was high and kinked, a n d this is the real cause of the disturbance. At operation dense adhesions were found in the area of the stoma. The afferent loop was long but was not distended at operation, but this is not surprising as the loop becomes empty and immobile due to continuous aspiration and general anaesthesia. The symptoms were completely relieved by division of the adhesions and conversion to a Billroth I type of gastrectomy.

In another patient with similar symptoms (Fig. 31) afferent loop filling with distension and excessive motility also occurred. Again there was kinking of the efferent loop causing partial obstruction and deviation of barium into the afferent loop.

FIG. 31A Fm. 32A FiG. 33A

FIG. 31B FIG. 32s FIG. 33n Flo. 31, A and B--Polya partial gastrectomy. Afferent loop high in position and showing considerable stasis and dilatation. The efferent loop is kinked. FIG. 32, A and B--Polya partial gastrectomy. Efferent loop obstruction with dilatation of jejunum adjacent to the stoma. FIG. 33, A and B~Po lya partial gastrectomy. The

efferent loop is high in position and kinked. The jejunum adjacent to the stoma is dilated.


The opening of the afferent loop was high in position and at operation this was found to be due to adhesions to the undersurface of the liver; dense adhesions were also present in the upper abdomen. Division of the adhesions and conversion to a Billroth I type gastrectomy relieved the symptoms.

We have called these disturbances afferent loop abnormalities to distinguish them from afferent loop syndrome where there is no filling of the loop.

2. Efferent loop disturbanees,--However, not all these patients with bile-stained vomiting and epigastric discomfort will show an afferent loop abnormality. These patients are perplexing and often have negative serial conventional barium meals. However, in some of these patients one may find a motility disturbance of the efferent loop on cinefluorography. Kinking of the efferent loop with partial obstruction may develop following adhesions caused by peritoneal soiling, post- operative leakage and haematoma formation, and later by the development of recurrent ulceration. The jejunum attached to the stoma and proximal to the obstruction becomes dilated and on spot films may appear to be part of the gastric remnant. However, cinefluorography will demonstrate that this part has the excessive peristaltic activity of an obstructed jejunal loop. One often sees an active see-saw like motion of barium between the afferent and efferent loops.

A patient who had had a Polya gastrectomy for duodenal ulcer and later a vagotomy for stomal ulceration developed further attacks of epigastric pain. Cinefluorography revealed a distended abnormally active segment of jejunum adjacent to the stoma (Fig. 32) and at operation a stomal ulcer with profuse adhesions and oedema was found. The profuse adhesions were producing efferent loop obstruction, and this explained the radiological findings. Only on a cine film was it possible to distinguish the obstructed jejunal loop :from the adjacent gastric remnant. The Polya gastrectomy was converted to a Billroth I type of gastrectomy, but unfortunately this did not relieve the symptoms as he developed further obstruction to the jejunum from intraperitoneal abscesses and required yet a further operation--a gastro- jejunostomy, to relieve this.

Another patient complained of epigastric pain and bilious vomiting, and cinefluorography demonstrated the ballooning out of the jejunum adjacent

to the stoma, and this was due to distortion of the efferent loop, producing partial obstruction. At operation the afferent loop was wide and long whereas the efferent loop was thickened and narrowed. An enterostomy was performed with relief of the patient's symptoms.

Two other patients with similar symptoms showed similar changes. One showed considerable ballooning of the jejunum adjacent to the stoma, and the efferent loop was kinked and high in position (Fig. 33) and grossly abnormal movement was observed. These patients are still under review and there has been no surgical intervention.

In some patients a sliding hiatus hernia may be discovered and may be a cause of continuing discomfort. In some patients this may follow the operation, particularly when vagotomy has been performed. In others, the hernia may be precipi- tated by obstruction at the stoma just as pyloric stenosis may have the same effect in the intact stomach. However, it may be difficult to be certain that the hernia was not present before the operation. These two patients with efferent loop obstruction also had symptoms of regurgitation and were shown to have sliding hiatus herniae.

We consider that cinefluorography has a place in the examination of the stomach after operation. It is particularly useful in demonstrating mechanical disturbances and in assessing stomal ulceration.

SUMMARY

A review is presented of the diagnostic scope and the value of radiological examinations in the management of complications encountered following abdominal surgery.

REFERENCES BAKER, L. W. • DUDLEY, H. A. F. (1961). Lancet, 2, 517. BEVAN, P. G. (1961). Brit. reed. o r. 2, 609. ELLIOT, K. A., ELLIOT, G. B. & Pow, R. E. (1961). Brit. J.

Radiol. 34, 622. FRIMANN-DAI-IL, J. (1960). Roentgen Examinations in Acute

Abdominal Diseases, 2nd ed. Springfield: Thomas. GREENING, J. R. & PROCTOR, N. M. (1961). Personal

communication. HARLEY, H. R. S. (1955). Subphrenic Abscess. Oxford:

Blackwell. SCOTT, J. E. S. & WH1TES~DE, C. G. (1956). Lancet, 2, 1330. StSK, P. B. (1961). Radiology, 77, 103. STAMMERS, F. A. R. (1958-59). J. roy. Coll. Surg. Edinb.

4, 121. WELLS, C. A. & MACPI-rEE, I. W. (1952). Lancet, 2, 1189.

radiology of the post-operative abdomen

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