The Value of Gastrografin in the Differential Diagnosis of Paralytic Ileus Versus Mechanical Intestinal Obstruction:

A Cr i t i ca l R e v i e w a n d R e p o r t o f T w o Cases*

MICHAEL ZER, M.D., DAN KAZNELSON, M.D., D.M.D., Zvl FEIGENBERG, M.D.,

MOSHE D'INTSMAN, M . D .

From the Department o] Surgery "A", Beilinson Medical Center, Petah Tiqva, and The Sackler School o] Medicine, Tel Aviv University, Israel

USE Of the water-soluble contrast medium, Gastrografin,| as an aid in the differential diagnosis between paralytic ileus and me- chanical intestinal obstruction has been reported repeatedly. 2-8 T h e reliability of using Gastrografin for this purpose has been controversial, and thus this use has not gained general acceptance. In 1972, Zer et al. reported the use of Gastrografin as a therapeutic agent in stomal malfunction after gastric resection. 9 Since then, the present authors have been using Gastro- grafin in cases in which difficulties have been encountered in the differential diag- nosis of paralytic ileus versus any type of suspected intestinal obstruction. In general, this method has proved reliable, without serious complications or dangers arising from the few diagnostic failures met with. Recently, however, we encountered two cases in which the presence of serious post- operative conditions was masked by the fact that the roentgenographic contrast exami- nation using Gastrografin indicated the diagnosis of paralytic ileus. Consequently, in these cases the decisions regarding urgent, mandatory surgical revision of the abdomen were dangerously delayed. As a result of these failures, the use of Gastrografin in the differential diagnosis of ileus was critically reviewed. This review is presented, together

* Received for publication November 23, 1976. Address reprint requests to Dr. Dintsman: Head,

Department of Surgery A, Beilinson Hospital, Petah Tiqva, Israel.

Dis. Col. & Rect. October 1977

with a report of the two cases that initi- ated it.

Materials and Methods

Throughou t the years 1973-1975, 41 cases in which the diagnostic problem of differ- entiation between paralytic ileus and me- chanical intestinal obstruction was not solved initially by physical examination and plain abdominal roentgenograms were en- countered in the surgical department. In these cases, when a conservative therapeutic trial including nasogastric drainage and hypertonic MgSO4 enemas had failed, 30--40 ml Gastrografin were administered orally or through the nasogastric tube. Serial ab- dominal roentgenograms were then ob- tained at hourly intervals for three to five hours. When during this period the pres- ence of Gastrografin in the colon could be demonstrated (Figs. 1 and 2), or when diar- rhea was provoked, the examination was rated "obstruction-negative" and surgical treatment was withheld except when defi- nite signs of peritoneal irritation appeared. Failure of the contrast medium to reach the colon within the above-mentioned interval was interpreted as "obstruction-positive" and the need for urgent surgical exploration reconsidered.

Twenty-two of the patients were men and 19, women. Mean age was 63 years (range 26-86 years).

For evaluation of the results, the series was divided into three groups: Group I (16

573 Volume 20 Number 7

574

FIG. 1. Cont ras t examina t ion , obst ruct ion-nega- tive. T h e colon is clearly demonst ra ted . A small a m o u n t of the contrast m e d i u m is still present in the s tomach. Fi lm exposed 45 minu te s after admin- is trat ion of Gastrografin.

ZER, E T AL. Dis. Col. & Rcct. October 1977

eight cases and inconclusive in one, that of a patient who vomited following adminis- tration of Gastrografin. Thus, diagnostic reliability in this subgroup was 89 per cent.

In the subgroup of two cases of patients who had paralytic ileus (I B o) resulting from mild postoperative peritonitis (probably from contamination at time of operation), reliability was zero, as the Gastrografin ex- aminations in these cases were obstruction- positive. Notwithstanding the results of the contrast examinations, these patients were not subjected to reoperation because of favorable responses to conservative therapy. This, of course, does not detract from the failure of the Gastrografin examination, as the patients would have been submitted to

cases), patients who showed signs of "ileus" in the early postoperative period following gastrointestinal operations; Group II (12 cases), patients who were admitted to the surgical depar tment with signs of paralytic ileus/intestinal obstruction, and who had past histories of abdominal operations; Group III (13 cases), patients admitted with signs of paralytic ileus/intestinal ob- struction, without any previous abdominal operation.

For the purpose of this review, the reli- ability of the Gastrografin examination was defined as the relative number of cases in which a correct decision could be made for or against surgical treatment. These cases did not always coincide with those in which the presence or absence of obstruction was correctly demonstrated, as is evident in the two cases described below.

Results

Group I--Early Postoperative Ileus

(Table I): In the subgroup of nine cases of "reactive" postoperative ileus (l B1), the examinations were obstruction-negative in

Fro. 2. Cont ras t examina t ion , obs t ruc t ion-nega- tive. Almost the ent i re bowel is demons t ra ted .

Volume 20 5 7 5 Number 7

GASTROGRAFIN IN DIFFERENTIAL DIAGNOSIS

TABLE 1. Group I--Early Postoperative lleus--16 Cases

Result of Examinat ion

Obstruction Obstruct ion Positive Negative

Number (Surgery (Surgery Not Reliability* of Patients Indicated) Indicated) Inconclusive (Per Cent)

A. Initial surgical procedure

Gastrectomy for duodenal ulcer 8

Gastrectomy for neoplasm 4

Resection of colon 1 Resection of small bowel 1 Abdominoperineal resection 2

TOTAL 16

B. Underlying cause of ileus 1. Paralytic ("reactive" or electrolyte

imbalance) 9 2. Paralytic (due to postoperative

peritonitis) 2 3. Paralytic (due to anastomotic leakage

or gangrenous bowel) 2 t 4. Intestinal obstruction (due to

adhesions) 3

TOTAL 16

- - 8 1 89

2 -- -- 0

- 2 t - 0

3 -- -- 100

5 10 1 69

* See text for definition of reliability. tThe two cases reported in detail.

unnecessary reopera t ion had the results been followed bl indly as criteria for surgical t reatment.

I n the two instances of paralyt ic ileus (I B3) caused by anastomotic leakage and gangrene of the bowel, respectively, the Gastrografin examinat ions were obstructive- negative, i.e., surgical t rea tment was not in- dicated. Th i s migh t be considered a correct diagnostic conclusion insofar as no intesti- nal obst ruct ion was indeed present. How- ever, these two cases were listed as failures because the examina t ion did not disclose the presence of serious in t ra -abdominal complicat ions requi r ing immedia te surgical intervent ion. These are the two cases tha t are repor ted in detail.

I n the four th subgroup (I B 0 of early postoperat ive intestinal obstruct ion, (two cases fol lowing part ial gastrectomy and one fol lowing resection of the small bowel), the

condi t ion was correctly diagnosed f rom the contrast examina t ion and reopera t ion was per formed accordingly.

T h e overall diagnost ic reliabili ty in Group I was 69 per cent (11 of 16 cases).

G r o u p I I - - L a t e P o s t o p e r a t i v e I l e u s

(Tab le 2): I n the subgroup (II Bx) of five cases of incomplete intestinal obstruct ion, the Gastrografin examina t ion was obstruc- tion-positive in two cases. Thus , diagnost ic reliability in this subgroup was only 40 per cent. T h e three pat ients in w h o m the exami- na t ion failed to demons t ra te obst ruct ion

were opera ted on a few days later because their clinical condit ions did not improve. T h e delay of surgical t rea tment did not

cause any fur ther complicat ion.

I n the second subgroup (IIB._,), consist ing of four cases of complete intestinal obstruc- tion, diagnost ic reliability was 100 per cent,

576

TABLE 2.

ZER, ET AL.

Group l l--Late Postoperative lleus--12 Cases

Dis. Col. & Rect. October 1977

Result of Examination

Obstruction Obstruction Positive Negative

Number (Surgery (Surgery Not of Patients Indicated) Indicated)

Reliability (Per Cent)

A. Initial surgical procedure Gastrectomy

Staging laparotomy for Hodgkin's lymphoma

Resection of intestine

Abdominoperineal resection

Cholecystectomy

Gynecologic surgery

TOTAL

B. Underlying cause of ileus

1. Incomplete intestinal obstruction a. Due to adhesions b. Due to neoplasm

2. Complete intestinal obstruction a. Due to adhesions b. Due to neoplasm

3. Fecal impaction

4. Abdominal wall abscess (adjacent to colostomy)

TOTAL

1

1

3

2

1

4

12

5 2 2 1 1 $ 1 2

3 40

4 4 - - 100

2 w

1

12 6

2 100

1 100

6 75

TABLE 3. Group Ill--Patients without Previous Abdominal Surgery

Result of Examination

Obstruction Obstruction Positive Negative

Underlying Cause of Number of (Surgery (Surgery Not Ileus Patients Indicated) Indicated) Inconclusive

Reliability (Per Cent)

I. Renal colic 3 - 2 1 67

2. Pancreatitis 2 - 1 '1 50

3. Mesenteric ischemia 4 3 1 - 75

4. Intramural hematoma

("anticoagulant ileus") 1 1 - - 100

5. Pseudo-obstruction of the bowel (generalized carcinomat0sis ) 3 . 2 1 - 33

TOTAL 13 6 5 2 62

as was also t r u e fo r t h e r e m a i n d e r o f G r o u p

I I ( two cases o f fecal i m p a c t i o n a n d o n e o f

a b d o m i n a l - w a l l abscess a d j a c e n t , to a colos-

t o m y loop) .

T h e o v e r a l l d i a g n o s t i c r e l i a b i l i t y i n

G r o u p I I was 75 p e r cen t ( n i n e o f 12 cases).

G r o u p I I I - - P a t i e n t s w i t h o u t P r e v i o u s

A b d o m i n a l S u r g e r y ( T a b l e 3): R e s u l t s i n

th is g r o u p a re c o n t r o v e r s i a l , i n t h a t i t in-

c l u d e d cases o f i l eus c a u s e d by a v a r i e t y o f

c o n d i t i o n s , s o m e o f w h i c h i n c l u d e d b o t h

p a r a l y t i c a n d o b s t r u c t i v e e l e m e n t s . I n add i -

Volurae20 G A S T R O G R A H N IN D I F F E R E N T I A L D I A G N O S I S 577 Number 7

Fro. 3. Patient 1. A (leIt), several distended loops of small and large intestine can be seen. B (right) , contrast examination, obstruction-negative. Gastrog-rafin is present in the right colon. The rectum is faintly outlined by the contrast medium.

t ion, the ind ica t ions for surgical t r e a tmen t in some of the ins tances were no t unequivo- cal. T h e d iagnos t i c r e l i ab i l i t y of the Gastro- graf in e x a m i n a t i o n in this g r o u p may thus be cons ide red a r o u g h a p p r o x i m a t i o n only.

I n the s u b g r o u p of cases of pa ra ly t i c i leus ( I l l a ) r e su l t ing f rom rena l colic, the Gastro- graf in e x a m i n a t i o n was obs t ruc t ion-nega t ive in two cases and inconclus ive in one, tha t of a p a t i e n t who v o m i t e d fo l lowing adminis - t r a t i o n of the con t ras t med ium. R e l i a b i l i t y in this s u b g r o u p was 67 per cent.

I n the two cases of pa ra ly t i c i leus caused by panc rea t i t i s (lII. ,) the e x a m i n a t i o n was obs t ruc t ion -nega t ive in one case and incon- clusive in the o ther . R e l i a b i l i t y was 50 per cent.

I n the t h i rd s u b g r o u p ( l l la) , cases of pa-

t ients who had mesenter ic ischemia, no at-

t e m p t was made to d i s t ingu i sh be tween

acu te a n d subacu te ischemia, as both , for

the p resen t purpose , were cons idered indi-

ca t ions for surgical t rea tment . T h e Gastro-

graf in e x a m i n a t i o n was obs t ruc t ion-pos i t ive

in th ree cases a n d nega t ive in one. T h e

r e l i a b i l i t y in this subg roup was thus esti-

m a t e d to be 75 p e r cent.

I n the one case of a pa t i en t who h a d a

large i n t r a m u r a l h e m a t o m a of the bowel

( " a n t i c o a g u l a n t i leus") , the con t ras t exami- n a t i o n was obs t ruc t ion-pos i t ive . At opera- t ion, the h e m a t o m a was seen to have caused comple t e obs t ruc t i on of the bowel.

In the cases of " p s e u d o - o b s t r u c t i o n " of the bowel (III.~) r e su l t i ng f rom genera l i zed carc inomatos is , surgical t r e a t m e n t was not cons idered ind ica ted , a l t h o u g h in some cases ope ra t ive i n t e r v e n t i o n may i n d e e d be needed to decompress the bowel. 1 In this subg roup the e x a m i n a t i o n was obs t ruc t ion- posi t ive in two cases a n d negat ive in one. T h e r e l i ab i l i t y was 33 per cent.

T h e overa l l d i agnos t i c r e l i ab i l i t y ill G r o u p I l l was 62 per cent (e ight of 13 cases).

R e p o r t o f T w o C a s e s

Patient 1: A 64-year-old man had resection of the sigmoid colon because of carcinoma. On the fourth postoperative day abdominal distention and vomit- ing appeared. Body temperature was slightly ele- vated (100.0 F), and signs of peritoneal irritation were absent. Plain roentgenograms of the abdomen demonstrated several distended loops of both large and small intestine, consistent with the diagnosis of paralytic ileus. A nasogastric tube was inserted and drained bilious fluid. As no clinical improvement was evident within 12 hours, 40 ml of Gastrografin were administered. Abdominal roentgenograms ob- tained two hours later revealed contrast medium in the right colon. In addition, small amounts of Gastrografin were present in the rectum (Fig. 3). Results of the examination were interpreted as

578 ZER, E T AL. Dis. Col. & Rect. October 1977

obstruction-negative; this was confirmed later by the passage of a soft stool. Accordingly, conserva- tive therapy was continued for 48 hours, the gastric tube draining large amounts (3,000 mi/24 hours) of bilious fluid. However, as the patient's condition failed to improve, surgical exploration was done on the seventh postoperative day and revealed a leak of the colonic anastomosis. The area of leakage had been walled off by several loops of small intestine, preventing generalized peritonitis. Colostomy was performed. The patient recovered promptly and was discharged on the fifteenth day after reoperation.

Patient 2: A 69-year-old woman was urgently transferred to the surgical department because of acute surgical abdomen, associated with hypovolemic shock. Massive intravenous replacement therapy was instituted and the patient was taken to the operating room. At laparotomy mesenteric-vein thrombosis was found, with gangrene of nearly all of the small bowel from the ligament of Treitz dis- tally, leaving about 90 cm of apparently viable ileum. Resection of the small intestine with a duodeno-ileal anastomosis was performed. The colon appeared viable, although no pulse could be clearly observed in its blood vessels. This fact was attributed to low blood pressure (80/60 mm Hg) at the time of operation. Postoperatively, intra- venous replacement and supportive therapy was continued, including tow-molecular-weight dextran and antibiotics in massive doses. The patient's gen- eral condition improved and the blood pressure was stable at 130-140/80 mm Hg. The nasogastric tube, however, contin{led to drain large amounts (2,200 ml/24 hours) of bilious fluid, and the differential diagnosis was anastomotic malfunction versus high intestinal obstruction. On the sixth postoperative day, 30 ml of Gastrografin were administered through the gastric tube. Serial abdominal roent- genograms were demonstrated gastric stasis and slow passage of the contrast medium into the bowel. After four hours, however, the colon was clearly demonstrated, and after two more hours a single soft stool was passed. Results of the examination were interpreted as obstruction-negative, and a diagnosis of paralytic ileus was made. On the fol- lowing day the amount of fluid draining through the nasogastric tube was markedly reduced and the tube was withdrawn. The patient's condition con- tinued to improve, and on the eighth postoperative day she was taking food by mouth without vomiting.

On the tenth postoperative day the patient's condition suddenly deteriorated. Signs of septic shock and peritoneal irritation appeared, and the patient was urgently transferred to the operating room, anastomotic leakage being suspected. At re- laparotomy segmental gangrene of the splenic flex- ure of the colon was found, with gross contamina- tion of the peritoneal cavity. Exteriorization of the colon was performed, but the patient died on the following day, not having recovered from septic shock.

D i s c u s s i o n

T h e mos t r e l i a b l e d i a g n o s t i c a i d in the

d i f f e r en t i a l d i agnos i s of p a r a l y t i c i l eus ver-

sus i n t e s t i na l o b s t r u c t i o n is b e y o n d d o u b t

the p l a i n a b d o m i n a l r o e n t g e n o g r a m . 2 . 3, 6. 7

T h e d i agnos i s is based u p o n i n t e r p r e t a t i o n

of the d i s t r i b u t i o n o f gas a n d f lu ids in var i -

ous par t s of the i n t e s t i n a l l u m e n , w h i c h is

d e c e p t i v e in a m i n o r i t y of cases o n l y ) C o l e t t i

a n d Bossar t 2 f o u n d t h a t t he a c c u r a c y of t he

p l a i n a b d o m i n a l r o e n t g e n o g r a m in t h e dif-

f e r e n t i a l d i agnos i s o f i l eus is as h i g h as 80

p e r cent , w h i l e Suf i an a n d M a t s u m o t o re-

p o r t e d a l o w e r f igure of 60 p e r c e n t >

In c o n t r o v e r s i a l cases of i leus , ser ia l expo-

sures o f t he passage o f G a s t r o g r a f i n t h r o u g h

the g a s t r o i n t e s t i n a l t r ac t m a y be used as a

v a l u a b l e a d d i t i o n a l d i a g n o s t i c a id , b u t i t is

u n d e r no c i r c u m s t a n c e s s u i t a b l e as a subst i-

t u t i o n for the p l a i n a b d o m i n a l r o e n t g e n o -

g r am. G a s t r o g r a f i n is a w a t e r - s o l u b l e con-

t ras t m e d i u m t h a t possesses m a n y a d v a n -

tages o v e r ba r ium.4 .9 I t is c h a r a c t e r i z e d by

r a p i d passage t h r o u g h the s m a l l b o w e l . I n

a h e a l t h y subjec t , G a s t r o g r a f i n , a d m i n i s -

t e red pe ro ra l l y , r eaches t he c e c u m in an

a v e r a g e of 45 m i n u t e s ( r a n g e 3 0 - 9 0 m i n -

utes). A de lay of t h r ee h o u r s o r m o r e is

h i g h l y i n d i c a t i v e of i n t e s t i n a l o b s t r u c t i o n .

E p s t e i n 3 r e p o r t e d a sa t i s f ac to ry c o r r e l a t i o n

b e t w e e n resul t s o f t he c o n t r a s t e x a m i n a t i o n

u s ing G a s t r o g r a f i n a n d c l i n i ca l f i nd ings in

a g r o u p of 14 pat ients . . Su f i an a n d Matsu -

m o t o 6 r e p o r t e d a n e s t i m a t e d r e l i a b i l i t y o f

o n l y 50 p e r cent . I n the p r e s e n t series, t he

r e l i a b i l i t y a p p r o x i m a t e d 70 p e r cent .

G a s t r o g r a f i n is s u p e r i o r to b a r i u m in t h a t

it m a y be used e v e n w h e n an a n a s t o m o t i c

l eak is suspec ted , because i t does n o t cause

i r r i t a t i o n to t he p e r i t o n e a l cav i ty . F u r t h e r -

more , i t does n o t b lock the i n t e s t i ne , o r

cause a g g r a v a t i o n o f an a l r e a d y e x i s t i n g in-

t e s t ina l o b s t r u c t i o n . T h e phys i ca l p r o p e r t i e s

of G a s t r o g r a f i n e n a b l e i t to pass t h r o u g h a

s e g m e n t o f i leus a n d e v e n t h r o u g h an a rea

of i n c o m p l e t e m e c h a n i c a l o b s t r u c t i o n . Con-

s equen t l y , the passage of G a s t r o g r a f i n , c l in i -

Volume 20 Number 7

GASTROGRAFIN IN DIFFERENTIAL DIAGNOSIS 579

cally expressed as diarrhea when the con- trast med ium reaches the rectum, does not definitely prove that passage of the bowel contents is poss ib le : Th i s d iar rhea should be followed by at least one addi t ional , spontaneous passage of stool in order to yield a result of the examina t ion that may justifiably be in terpreted as "obstruct ion- negative." W h e n this does not happen , the presence of intestinal obst ruct ion should still be suspected, and at any rate, the diagnosis of paralyt ic ileus should be re-evaluated.

I n medical l i terature, little considerat ion has been given to the possible hazards arising f rom the uncri t ical acceptance of the results of the contrast examinat ion , using Gastro- grafin, in cases of ileus. Sykes and Schofield 7 men t ion that the use of this diagnostic me thod may cause undue delay of a manda- tory reoperat ion. Thus , they discourage its e m p l o y m e n t in cases of ileus and recom- mend reliance solely upon observations made f rom the p la in abdomina l roentgeno- gram. Ill the op in ion of the present authors, the contrast examina t ion using Gastrografin can be a diagnost ic aid of considerable value in controversial cases of ileus, so long as the result is looked u p o n with a certain a m o u n t of criticism. Th i s critical a t t i tude towards the clinically unconf i rmed roentgenologic diagnosis of "obstruct ion-negat ive" is of p a r a m o u n t importance. In the absence of clinical improvemen t of the pat ient ' s condi- tion, surgical t rea tment should be decided u p o n wi thou t hesi tat ion in order to diagnose and treat possible serious under ly ing condi- tions, which may have been masked by re- sults of the contrast examina t ion using Gas- trografin. Th i s is clearly i l lustrated in the cases presented.

Summary

T w o cases in which serious intra-abdomi- nal complicat ions were masked by results of the contrast examina t ion using Gastrografin

were encountered. T h i s caused the authors to review critically the use of Gastrografin in the differential diagnosis of paralyt ic ileus versus mechanica l intestinal obstruc- tion. In a series of 41 cases in which the diagnostic p rob lem was not solved initially by means of physical examina t ion and plain abdomina l roentgenograms, the Gastro- grafin examina t ion proved reliable in 28 (68 per cent). T h e reliabil i ty of the exami- nat ion was defined as the relative n u m b e r of cases in which a correct decision could be made for or against surgical operat ion. I t is concluded that Gastrografin is a valuable diagnostic aid in controversial cases of ileus. A "negat ive" result of the examinat ion , however, should never be al lowed to d a m p the surgeon's awareness of possible serious in t ra -abdominal condit ions, which the con- trast examina t ion has failed to disclose and which require immedia te surgical intervention.

References

1. Chaimotf C, Dintsman M: The pseudo-obstruc- tion of bowel syndrome: A suggestion of a simple surgical remedy. Am J Proctol 25:39 (Feb) 1974

9. Coletti L, Bossart PA: Intestinal obstruction during the early postoperative period. Arch Surg 88:774, 1964

3. Epstein BS: Nonabsorbable water-soluble con- trast mediums: Their use in diagnosis of intestinal obstruction. JAMA 165:44, 1957

4. Lessman FP, Lilienfeld RM: Gastrografin as water soluble contrast medium in roentgen examination" of the G.I. tract. Acta Radiol 51:170, 1959

5. Samuel E, Duncan JG, Philp T, et al: Radiology of the post-operative abdomen. Clin Radiol 14:133, 1963

6. Sufian S, Matsumoto T: Intestinal obstruction. Am J Surg 180:9, 1975

7. Sykes PA, Schofield PF: Early postoperative small bowel obstruction. Br J Surg 61:594, 1974

8. Vest B, Margulis AR: The roentgen diagnosis of postoperative ileus-obstruction. Surg Gynecol Obstet 115:421, 1962

9. Zer M, Dintsman M, Chaimoff C: Gastrografin as a therapeutic agent in stomal malfunction after gastric resection. Am J Surg 124:591, 1972