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
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