Technical

Developments

Transhepatic

Portal

Transplant Nancy Walter Robert Noninvasive

Venography

in Potential

Pediatric

Liver

ReciDients’

K. Rollins, S. Andrews, E. Barton, imaging anatomy

teric venous diatric liver

and Instrumentation

MD MD MD of portomesenin prospective

transplant

pemay

recipients

be limited by the small size of the yesA simple technique of percutaneous transhepatic portal venography was developed that involves the use of a 22gauge needle and hand injection of contrast material. The technique was used in six infants (aged 4-15 months) with portal hypertension and end-stage liver sels.

disease due to biliary vein was diagnostically

atresia. The opacified

four of the six patients. complications Index Portal

related

terms:

Liver,

vein,

anatomy,

Radiology

D

1990;

There to the

portal in

were

transplantation,

of extrahepatic

a simple

Materials

technique

and

for

I

From

(N.K.R., University

the

included six infants with known portal end-stage liver dis-

Departments

of Radiology

R.E.B.) and Pediatric of Texas

percu-

venograliver trans-

Methods

The study group (aged 4-15 months) hypertension and

Surgery

Southwestern

(W.S.A.),

Medical

Center, and Children’s Medical Center, 1935 Motor St. Dallas TX 75235. Received July 3, 1989; revision requested August 4; revision re-

ceived August 15; accepted reprint requests to N.K.R. C RSNA, 1990

262

#{149} Radiology

shows

shows

patent

portal with

main

venogram

polysplenia.

761.91

95.124

taneous transhepatic portal phy in potential pediatric plant recipients.

portal

2. 1, 2. (1) Transhepatic portal venogram. Digital subtracted image vein (arrow) and a spontaneous splenorenal shunt. (2) Transhepatic excellent opacification of the portal and splenic veins in a patient

procedure.

yenous anatomy is necessary in the child being considered for orthotopic liver transplantation. Ultrasound (US) remains the initial, and frequently the only, imaging study needed in pnetransplantation evaluation (1). Howeyen, sonognaphic definition of abdominab venous structures may be limited by overlying bowel gas or high position of the liver relative to the costal margin. Magnetic resonance (MR) imaging has clinical utility in pretnansplantation evaluation of pediatric patients (2,3), but occasionally the portal venous anatomy remains unclean. We describe

Figures

no

174:262-263

ELINEATION

1.

August

18. Address

ease due to biliary atnesia. US and MR imaging had failed to show the extrahepatic portal vein either because of overlying bowel gas at US, the small size of the venous structures, on the presence of numerous vanices in the liver hilus. Two patients had moderate ascites; one had a prothrombin time of 17 seconds (normal, 10-13 seconds), and the other had a normal prothrombin time. The remaining four patients had no ascites and normal coagulation times. Five patients received no antibiotics; one patient received antibiotics prior to the procedure because of fever of uncertain origin that was suspected to be due to cholangitis. With the patients under general anesthesia and with the use of aseptic technique, the liven was punctured in the right mida.xillary line with a 10-cm, 22-gauge Chiba needle (Cook, Bloomington, md). The needle was advanced

procedure, the needle was simply withdrawn. No compression bandages were applied. Five patients were discharged within 24 hours of the procedure; the

with

dune.

A patent

was

demonstrated

tenic

venography.

died

several related

fluonoscopic

guidance

in

a cephal-

ic direction toward T-11 or T-12. No attempt was made by the patient to suspend respiration during movement of the needle. The stybet was removed, and the needle was slowly withdrawn while a small amount of contrast matenab (iopamidob, Isovue 300; Squibb, New Brunswick, NJ) was injected. The procedure was repeated until injection of contrast material showed the tip of the needle to be within a portal venous radicle. At this point, contrast material was hand injected during serial filming on digital acquisition at a rate of 1 or 2 frames pen second. The total volume of contrast material used varied from 4 to 1 1 mL, and the total procedure time ranged from 1 1 to 20 minutes. At the termination of the

sixth for

patient

remained

systemic

in

antibiotic

the

hospital

therapy.

Results Diagnostic opacification of the portal vein was achieved in four of the six patients. Figures 1 and 2 illustrate excellent

retrograde

tal the

fourth

trast

opacification

achieved

veins

patient,

material

and the

study.

the

opacified.

within portal

vein

the In

the vein

(Fig

portal

pletely opacified. In two patients not

subhepatic

panenchyma The

the

patients.

extravasation

into

hepatic

of

in three

In of conspace

3) limited

incom-

was

portal

one,

por-

vein

was

antegnade

flow

intnahepatic was seen

radicles of the during the pnoceextrahepatic portal vein by operative mesenThe

other

patient

of complications hypertension. No further investigation of the portal venous system had been performed. There were no complications rebated to the procedure. Neither patient with ascites had any leakage of fluid at the puncture any

months to his

site.

No

later portal

bleeding

occurred

in

patient.

Discussion Noninvasive

vein may

size and

in infants

imaging

and

of

the

portal

young

children be unsuccessful due to the small of the abdominal venous structures the presence of lange vanices in the January

1990

liven

hilus. Invasive indirect techinclude flow-through arterial portography, operative mesenteric yenography, and splenoportognaphy. Visualization of the portal vein with anterial portography requires prolonged injection of contrast material into the celiac or superior mesentenic arteries, or both. The volume of contrast material required may exceed the recommended dose. Mesenteric venography requires a laparotomy and cannulation of a peripheral mesenteric venous radicle with a small catheter (4). The procedure may be complicated by the presence of highly vascular intraabdominal adhesions, as well as postoperative leakage of ascitic fluid. As with arterial portography and splenoportography, hepatofugal portal venous flow and preferential flow of contrast material into collateral veins may limit opacification of the portal vein, resulting in the erroneous diagnosis of portal vein occlusion (2,5). With splenoportography, the direct injection of contrast material into the splenic pulp may occasionally generate enough pressure to temporarily reverse the direction of flow in the portal vein, overcoming the problem of hepatofugal flow. Failure to opacify the portal vein with splenoportography is not necessarily indicative of portal vein occlusion, because the splenic vein may be occluded or the direction of portal venous flow may not have been reversed (2,6). Transhepatic portal venognaphy has been widely used in adults since the 1950s but has for the most part been replaced by flow-through arterial pontognaphy. Ascites and prolonged coagulation times are contraindications to routine transhepatic portal venography, which is usually performed with a 5- or 6-F catheter. Scattered references have been made to the technique of transhepatic portal venognaphy in children (7).

niques

Volume

174

#{149} Number

1

Figure

3.

fication; coronary

(a) Apparent filling defect (arrow) in the portal vein represents no thrombus was found at transplantation. (b) Subtracted image and splenic veins.

The

low-volume

portal

vein

slow-flow state of the small patients with portab hypertension may allow the use of a 22-gauge needle and hand injection of contrast material, although, as ilbustrated in Figure 3, incomplete opacification of the portal vein may occur, which results in the erroneous diagnosis of nonoccluding thrombus; however, this does not preclude transplantation. The major limitation of transhepatic portal venography is hepatopetal flow, which cannot be even temporarily reversed, as we saw in one of our patients. Failure to opacify the portal vein with this technique mandates that further investigation, such as operative mesenteric venography, be performed before the patient is rejected as a liver transplantation candidate. Our initial experience with percutaneous transhepatic portal venography using a 22-gauge needle suggests that it is safe and easy to perform. No leakage of ascitic fluid on bleeding occurred. Extravasation of contrast material, which may occur before a branch of the portal vein is entered, appears to have no clinical sequelae. Although our initial experience in

incomplete opacishows opacified

is limited, this procedure promises to have application in the preoperative evaluation of infants and young children with end-stage liver disease. U

References 1.

Ledesma-Medina A, et al.

J, Domingues

Pediatric

liver

Standardization

of preoperative

imaging. 2.

Day

R, Bowen

transplantation.

Radiology

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DL, Lepourneau

MR evaluation

I.

diagnostic

JG, Allan BP, et al. vein in pediatcandidates, AJR 1986;

of the portal

3,

ric liver transplant 147:1027-1030. Williams DM, Cho KJ, Aisen AM, et al. Portal hypertension evaluated by MR imaging. Radiology 1985; 157:703-706.

4.

Auvert

J, Michel

approach

tension. 5,

6.

Cardella giographic recipients.

to the

JR. Farge

C.

Radiological

of portal hyperProgr Pediatr Radiol 1968; 2:1-45. JF, Amplatz K. Preoperative anevaluation of prospective liver Radiol Clin North Am 1987;

25:299-308. Prohst P, Rysavy

diagnosis

SA, Amplatz

K.

proved safety of splenoportography plugging of the needle tract. AJR 131:445-449. 7,

Cardella

JF.

vascular

problems

tion.

Semin

Evaluation

Intervent

and

after liver Radiol

Imby 1978;

treatment

of

transplants1986;

3:130-

148.

Radiology

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Transhepatic protal venography in potential pediatric liver transplant recipients.

Noninvasive imaging of portomesenteric venous anatomy in prospective pediatric liver transplant recipients may be limited by the small size of the ves...
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