Genitourinary Raymond Michael

B. Dyer, MD Y. M. Chen, MD

Vicarious in Patients Ureteral

W. Gilpin, MD #{149} Ronald L Douglas Case, PhD

at intravenous

and

evi-

urogra-

occurs

with

greater

frequency when obstruction ciated with contrast material asation. Index

terms:

Contrast

Gallbladder, or obstruction, 82.84 82.1221

#{149}

Radiology

media, 762.91

effects,

762.91,

Ureter,

stenosis

#{149}

1990; 177:739-742

reprint

requests

#{176}RSNA, 1990

to R.B.D.

C

ONTRAST

materials

intravenously of the urinary most exclusively tion. Vicarious

nitrogen and creatinine levels obtained before or within 24 hours after the contmast material study were available for 41 patients.

administered

for opacification tract

are excreted by glomerular contrast material

alfiltracx-

cretion (VCME) has been considered a sign of impaired renal function (16). VCME has been reported in small series of patients with normal function, in whom it is most

sociated

with

unilateral

renal often as-

renal

disease,

such as umeteral obstruction (5,7-9). We undertook a retrospective study to determine the frequency with which VCME was seen on delayed radiogmaphs obtained following intravenous urography in patients with acute unilateral renal obstruction. Our findings indicate that VCME is

more

common

than

previously

preciated in these patients and more frequently when obstruction associated with contrast material tmavasation.

PATIENTS

is assoextrav-

I From the Department of Radiology, Bowman Gray School of Medicine, 300 5 Hawthorne Rd. Winston-Salem, NC 27103. From the 1989 RSNA scientific assembly. Received January 9, 1990; revision requested February 27; revision received June 22; accepted August 8. Ad-

dress

MD

Contrast Material Excretion with Acute Unilateral Obstruction’

phy, obtained at least 24 hours after injection of contrast material, were retrospectively studied. Vicarious contrast material excretion (VCME) as evidenced by gallbladder opacification on delayed radiographs was seen in 19 patients (42%), 10 of whom also showed extravasation of contrast material. A total of 15 of the 45 patients developed spontaneous extravasation; 10 (67%) showed VCME, while only nine of the 30 patients (30%) who did not have spontaneous extravasation of contrast material showed VCME. The creatinine level was elevated (>1.5 mg/dL [133 imol/L]) in four patients with VCME and in six patients without. This series indicates that VCME is more common than previously appreciated in patients with acute unilateral ureteral obstruction

Zagoria,

#{149}

Radiographs of 45 patients with dence of acute unilateral ureteral obstruction

J.

#{149} John

Radiology

AND

apoccurs is cx-

METHODS

Two hundred patients underwent intravenous urography between February 1986 and November 1988 to evaluate urinary tract obstruction. Patients with normal studies; evidence of chronic, bilateral, or postsurgical obstruction or obstruction in a solitary kidney; or radiologic evidence of cholecystectomy were cxcluded from review. Eighty-two patients were found to have acute unilateral obstruction from urinary tract stone disease. All intravenous urography was performed with use of a bolus injection of 100 mL of contrast material, and, in 45 patients, radiographs were obtained at least 24 hours after injection of contrast material. Those 45 patients, 41 men and four women ranging in age from 19 to 76 years (average, 44 years), made up the study group. A retrospective analysis was undertaken to determine the frequency of VCME as indicated by gallbladder opacification on the delayed radiographs. In

addition

to the presence

or absence

of

VCME, side and site of obstruction, stone size, and presence of spontaneous extravasation of contrast material as defined by Schwartz et a! (10) were noted. Blood urea

RESULTS Characteristics

of the

45 patients

are shown in Table 1 . Nineteen of the 45 patients (42%) had VCME as evidenced by gallbladder opacification.

Visualization

occurred graph

in four

alization, between tients, injection

of the

prior

gallbladder

to a 12-hour patients

4.5 hours after 12 and 24 hours and

more than in six patients

ization,

95 hours

patients atinine

with levels

mg/dL

[141-548

radio-

(earliest

24 hours (latest

after

VCME were

visu-

injection), in nine

injection).

were elevated

pa-

after visual-

All

male. Crc(1.6-6.2

smol/L])

in four

pa-

tients with VCME (two with and two without extravasation) and in six patients without VCME (1.7-2.1 mg/dL [150-185 mol/L]). Extravasation of contrast material

occurred (33%).

in 15 of the The

grade

45 patients

of extravasation

as

defined by Chapman et al (11), type of extravasation, and dose and type of contrast material in these 15 patients are listed in Table 2. Ten of the 15 patients (67%) with extmavasation had evidence of VCME (Fig 1), and nine of the 30 patients (30%) without extravasation

.043,

had

Yates

x2

VCME

corrected

2) (P

(Fig

method).

=

All

patients with extravasation of contrast material were male and all had small stones in the distal ureter. The stones were impacted at the uretero-

vesical

junction

in 10 of those

pa-

tients.

DISCUSSION In patients lam filtration,

with normal urographic

Abbreviation: VCME material excretion.

glomerucontrast

vicarious

ma-

contrast

739

:

‘a!.4

..,.e

.‘

I a.

b.

Figure

1.

(a) Radiograph

obtained

30 minutes

after

injection

of urographic

contrast

material

demonstrates

a persistent

dense

nephrogram

on the left. Calicectasis is noted, and fomnical rupture has occurred in the upper and midcalyceal groups, allowing entry of contrast material into the lymphatic system. Faint calcification is seen over the medial aspect of the right renal pelvis. (b) Radiograph of the right upper quadrant with the patient in the right posterior oblique position obtained 18 hours after injection of contrast material shows vicarious excretion of contrast material with opacification of the gallbladder. Several large radiolucent filling defects are identified within the gallbladder lumen (arrows), and a curvilinear calcification in the gallbladder neck, which proved to be a calcified gallstone, is also seen (arrowheads).

terial shows minimal hepatobiliary excretion. Less than 2% of the urographic dose of the diatrizoates and iothalamates is handled by hepatobiliary excretion (5,9,12,13), although this is the major alternative route of

contrast

material

excretion.

The

term

excretion has been used to describe biliary contrast material detected radiogmaphically following intravenous administration of contrast material. The initial reports of VCME following urographic dosage concerned vicarious

patients

with

postulated ular filtration mal disease

uremia

that

(1,2,4).

reduction due to renal led to prolonged

It was in glomerparenchyrecircu-

lation of contrast material with greatem protein binding as a result of prolonged intravascular contact. In addition, the acidosis often associated with uremia enhances the protein binding of the contrast molecule (5,14). Several isolated reports have appeared of VCME occurring in patients with normal renal function, most often associated with acute unilateral renal obstruction; however, the frequency of this occurrence is difficult to determine, and it has been considered rare (1,4,7). The mechanism proposed for the occurmence of VCME with acute unilateral renal obstruction is similar to that implicated in renal parenchymal dis740

Radiology

#{149}

Table 1 Characteristics of 45 Patients Ureteral Obstruction

with

Delayed

Radiographs No.

Characteristics Stone

and Acute

Unilateral

of Patients

With VCME

Without

VCME

size

Notseen 2mm

3mm Side of obstruction Right

Lelt Site of obstruction Proximal third Middle third Distal third Extravasation

1 10 8

3 5 18

11

9

8

17

0

3 3 20

2 17

Present

10

5

Absent

9

21

ease. It is thought that, despite the functioning of one kidney with normal glomerular filtration, obstruction of the other kidney increases circulation time sufficiently to allow protein binding in some instances. In addition, Shea and Pfister (5) have suggested that transient intracellular acidosis produced by obstruction may also increase protein binding, as does the acidosis that occurs in uremia. An additional factor that may prolong vascular contact of contrast materials in patients with acute unilateral renal obstruction, and thus pro-

mote

hepatobiliary

spontaneous First described

(15,16),

excretion,

spontaneous

sation

urinary

is thought

iologic structed

is

urinary extravasation. by Fuchs in 1930

“safety urinary

extrava-

to represent

valve” tract.

sure

within

the

may

cause

rupture

a phys-

for the Elevated

collecting

obpres-

system

of a caliceal

fomnix

more rarely, produce a direct tear in the renal pelvis. Contrast material then enters the renal sinus area or, less commonly, the venous or lymphatic system. With extensive cx(10,17)

or,

travasation, ter

the

contrast perirenal

material space

or dissect

December

may

eninfe-

1990

Figure 2. (a) Radiograph obtained 90 mmutes after intravenous administration of contrast material demonstrates a persistently dense nephrogram on the right, with mild pyelocaliectasis. Ureterectasis with columnization of contrast material is seen to the 1evel of a small stone (arrowhead) impacted at the ureterovesical junction. (b) Radiograph obtained 22 hours after injection of contrast material

demonstrates

opacification

of

the

gallbladder. The ureterovesical junction stone is again identified (arrowhead). No cxtravasation

was

seen

blood urea nitrogen were normal.

ous

renal

sence

this

in

and

or ureteral

patient,

and

creatinine

levels

surgery,

(c) abtract le-

of a destructive urinary (d) absence of external

sion,

trauma,

(e) absence of external compression, and (f) absence of pressure necrosis due to a stone. The presence of contrast

material

in the

soft

tissues,

circulation via the venous and phatic system, suggests increased

or me-

lym-

contact of contrast material with the vascular system by means of alternate routes of resorption. In early reports of this phenomenon, its occurrence was considered

rare.

b.

a.

Table 2 Relationship of Spontaneous with Extravasation

Urinary

Extravasation

and VCME

in the 15 Patients

Extravasation Patient No.

Grades

*

Type Type

3

Pyelosinus

1-

Diatrizoate

meglumine

1

Pyelolymphatic

+

Diatrizoate

meglumine

3 4

3 2

Pyelosinus/perirenal Pyelosinus

+ +

Diatrizoate Diatrizoate

meglumine meglumine

5

4

Pyelosinus/perirenal

6 7

4 4

Pyelosinus Pyelosinus

1

Pyelosinus

4 2 3 2 4 3 4

Pyelosinus Pyelosinus Pyelosinus Pyelosinus Pyelosinus Pyelosinus Pyelosinus

Numbers

refer

to the classification

and

pyelolymphatic

and

pyelolymphatic

+

Diatrizoate

meglumine

+ +

Diatrizoate Diatrizoate

meglumine meglumine

+

lohexol

+ +

Iohexol lohexol Diatrizoate

meglumine

lohexol Diatrizoate

meglumine

Diatrizoate Diatrizoate

meglumine meglumine

-

and

pyelolymphatic

-

of Chapman

et al (11): Grade

1

extravasation

grade 2 = extravasation about two or more calices or extending to the renal capsule, extravasation, and grade 4 periureteral/retroperitoneal extravasation. t + = patient experienced VCME, patient did not experience VCME. I Dose given to all patients was 100 mL.

riorly to outline variable lengths the ureter. Criteria proposed by Schwartz et al (10) for definition

Volume

of Materialt

1

8

pyelolymphatic

Contrast

2

9 10 11 12 13 14 15

and

VCMEt

177

Number

#{149}

3

of of

about grade

3

one

calix,

perirenal

spontaneous urinary extravasation include (a) absence of recent umeteral instrumentation, (b) absence of previ-

More

recently,

ranging in patients obstruction has been

from

pressure

of 80-100

frequencies

0.1% to 18% (11,18,19) with unilateral uretemal have been reported. It suggested that an absolute

mm

Hg

within

the collecting system is necessary to produce extravasation (18,20); in addition, the more rapid the rise in intrapelvic pressure, the more likely the occurrence of extravasation (1 1). Pressure within the collecting system is directly proportional to the degree and duration of acute obstruction and the dose and type of contrast material. Bernardino and McClennan (18) suggested that higher frequencies of extravasation can be expected with larger doses of contrast material and with use of high-osmolality contrast material because of the greater osmotic diuresis with resultant increase in collecting system pressure. In our series, extravasation occurred with use of both high(diatrizoate meglumine; Renografin-60, Squibb Diagnostics, Princeton, NJ) and low(iohexol; Omnipaque 300, Winthrop Pharmaceuticals, New York) osmolar contrast materials, but the difference was not significant. The presence of spontaneous unnary extravasation, with its release of pressure in the collecting system, tends to be associated with a more benign clinical course. Chapman et al (11), in a prospective series, noted that

patients

with

extravasation

Radiology

were #{149} 741

male, had less hydronephrosis, required less intervention for stones, and tended to have small stones (1-5

4.

Segall HD. Gallbladder visualization following the injection of diatrizoate. AJR

5.

Shea TE, Pfister RC. Opacification gallbladder by urographic contrast

vesical junction. Our series supports the tendency for distal stone impaction in patients with extravasation and the male preponderance. However, because our study included only four women, the association between sex and extravasation was not significant. The only postulated mechanism for male predominance

tients with extravasation had cvidence of VCME, and nine of the 30 patients without extravasation had VCME. The increased incidence of VCME in patients with extravasation was statistically significant. In view of the mechanism of VCME in patients with normal renal function, this association with extravasation is not unanticipated. Prolonged contact of contrast material with the vascular system promotes protein binding and may be enhanced by transitory acido-

in

sis associated

9.

mm)

impacted

the

at or near

occurrence

the

uretero-

of extravasation

of

with

obstruction.

which we are aware is that the male ureter is less compliant than the female ureter and, thus, more prone to the development of extravasation (11). Prior to the study, we had the impression that the occurrence of VCME was not rare. The occurrence of this phenomenon in patients with acute unilateral renal obstruction without other manifestations of renal parenchymal disease led to the retrospective analysis of the patient population described. Review of the creatmine levels in these patients revealed that elevated creatinine was more common in patients without VCME than in those with laboratory evidence of renal failure. A more common association in patients who developed VCME was the presence of spontaneous urinary extravasation. Spontaneous urinary extravasa-

The results from our series indicate that VCME in a patient population with acute unilateral ureteral obstruction is more common than has been previously reported. In addition, extravasation is believed to be more common than has been reported in the past and probably reflects current usage of higher doses of contrast material. In our series, the frequency of VCME may be artificially

tion

is not

generally

occurred

early

in the

course of urographic examination and was seen with both ionic and nonionic contrast materials. In some instances, this led to hospitalization, but, in most cases, delayed radiographs were obtained 24 hours or more after administration of contrast material for evaluation of stone migration because of the distal site of impaction and the anticipation of spontaneous passage. Among the 45 patients with delayed radiographs, VCME occurred in 42% and spontaneous urinary cxtravasation

in 33%.

Ten

of the

elevated

because

1969; 107:21-26.

AJR

6.

uncommon

in cases

1.

Becker Schwartz graphic

2.

15 pa3.

Arkless

R.

8.

10.

11.

12.

102:765-767. Holloway

A, Berdon

D. Vicarious media. Radiology

excretion 1968;

W, of urn90:243-

Clin

contrast North

media

Am

in

1972;

Gallbladder

H, Nance

on

excretory

J Urol

EP, Burks

1969; D, Winfield

creatinine. Invest Radiol 1988; 23:604-608. Schwartz A, Caine M, Hermann C, Bittermann W. Spontaneous renal extravasation during intravenous urography. AJR 1966; 98:27-40. Chapman JP, Gonzalez J, Diokno AC. Significance of urinary extravasation during renal colic. Urology 1987; 30:541-545. Ford KK, Wysong B, Thompson WM. Opacification

13.

seen

a case report.

AC. Vicarious excretion of contrast mcdiurn in patients without azotemia. Urology 1985; 25:201-203. Hopper KD, Weingast C, Rudikoff J, Thickman D. Vicarious excretion of water-soluble contrast media into the gallbladder in patients with normal serum

of the

intravenous

contrast

with

normal

renal

1983; Lautin

5:251-252. EM, Friedman

cretion

of contrast

gallbladder

following

injection

in patients

function.

Urol Radiol

AC.

Vicarious

media.

JAMA

cx-

1982;

247:1608-1610.

14.

15.

SokoloffJ, Talner cretion of sodium 1973; Fuchs

46:571-577. F. Cited

back-flow

17.

LB. The heterotopic cxiothalamate. Br J Radiol by: Olsson

in excretion

Acta Radiol

16.

0.

Studies

urography

on

(abstr).

1948; 30:501-502.

Fuchs F. Cited by: Sengpiel GW. Renal backflow in excretory urography. AJR 1957; 78:289-295. Harrow BR, Sloane

JA.

travasation

excretory

during

Pyelorenal

85:995-1005. ME, McClennan

cx-

urography.

J

18.

Urol 1961; Bernardino

19.

dose urography: incidence and relationship to spontaneous peripelvic extravasalion. AJR 1976; 127:373-376. Lindbom A. Fornix backflow in excretion

BL.

High

urography: its significance in the differential diagnosis of tuberculosis of the kid-

ney. Acta Radiol 1943: 24:411-418. Kohler R. Investigations on backflow retrograde

JA, Gregoire

Urographic

Radiol

urography:

20.

References

LB.

10:421-432. 7.

of obstruc-

tion and may be significantly increased in the presence of spontaneous urinary extravasation may obviate the necessity of invoking a renal failure mechanism when gallbladder opacification is detected in this patient population. U

1969; 107:763-768.

Talner uremia.

of hospitalization

for narcotic pain control and maintenance of a fasting state in anticipation of possible intervention in patients with a distally impacted stone. Both of these factors would favor increased concentration of urographic contrast material in the biliary systern. However, since only 45 of 82 patients had delayed radiographs, the overall frequency may yet be underestimated. An awareness that VCME

of the

media.

pyelography:

cal and clinical (suppl

study.

in

a roentgenologi-

Acta Radiol

1953;

99):1-92.

248. Chamberlain MJ, Sherwood T. The extrarenal excretion of d.iatrizoate in renal failure. Br J Radiol 1966; 39:765-770. Jancu J, Shapiro C. Extra-renal excretion of contrast material: a possible indicator of renal damage. Clin Radiol 1971; 22:219221.

742

Radiology

#{149}

December

1990