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167
Stenoses of Vascular Anastomoses After Hepatic Transplantation: Treatment with Balloon
Nigel
Raby1
J. Karani1 S. Thomas1 J
Roer ,
O’Gradv2 Williams2
Vascular
Angioplasty
complications
after liver transplantation
sites of anastomosis in the hepatic artery, experience with more than 600 liver transplants,
include
occlusion
or stenosis
portal vein, and vena cava. vascular stenoses have been
at the
From our identified
in 10 patients
and treated by balloon angioplasty in nine. Three patients with hepatic stenosis and deteriorating graft function were treated by balloon angioplasty with a coaxial technique. A specially designed catheter facilitated a successful femoral artery approach. Portal vein stenoses in three patients resulted in portal hypertension. These were treated by balloon dilatation via transhepatic catheterization of the portal vein. Stenoses of the suprahepatic caval anastomosis were dilated in three patients with severe lower limb edema. Technical success was achieved in all three cases of hepatic artery stenosis with improvement in graft function. Recurrent stenoses in two patients were successfully treated with repeated dilatations. Portal hypertension resolved in two of three patients after portal venoplasty. Dilatation of a caval stenosis resulted in the resolution of leg edema in all three cases. Repeated dilatation was required in one case. No reduction in the portal venous pressure gradient occurred after venoplasty in one case, and an ultimately fatal caval thrombosis developed in one patient with caval stenosis before venoplasty could be performed. Our experience suggests that balloon angioplasty of arterial and venous stenoses complicating hepatic transplantation carries little risk and is a useful procedure for the treatment of these problems. artery
AJR 157:167-171,
July 1991
During orthotopic liver transplantation, four vascular anastomoses are fashioned. The donor hepatic artery and portal vein are anastomosed to the recipient vessels. The intrahepatic portion of the inferior vena cava requires two anastomoses of donor to recipient cava: one at the level of the diaphragm (the suprahepatic cava) and one below the liver above the level of the renal vessels (the infrahepatic cava). Stenosis or occlusion of any of these anastomoses may occur postoperatively. In this report, we describe nine cases in which anastomotic stenoses were treated by percutaneous angioplasty with improvement in graft function or relief of other significant complications. Another patient with caval stenosis who developed fatal caval thrombosis proximal to a suprahepatic stenosis is also described.
Materials Received vision 1
ptal, 2
October 29, 1 990; accepted after re1 1 , 1991 . Department of Radiology, Kings College HosJanuary
Denmark Liver
Hill, London
Hill, London
Unit,
Kings
SE5 9RS,
SE5 9RS,
College
Hospital,
England.
0361-803X/91/1571-0167 ©American
Roentgen
England. Denmark
The 1 0 cases liver transplants. cases
of
graft
included in the study were culled Posttransplantation angiography failure
and
suspected
identify a specific cause and angiography, arterioportography, transfemoral
imaging. Ray Society
and Methods
the
site
approach,
Arterial
stenosis
of anastomosis
with
chronic
in patients and images
distal
our experience with more than 600 done to assess arterial patency in
rejection
in which
with biliary strictures inferior venacavography
obtained
was defined just
from was
on conventional
as a solitary
to the
origin
short
of the
liver
biopsy
or hepatic
were film
narrowing
gastroduodenal
and
had
abscesses.
failed
all performed with
digital
via
a
subtraction
of the hepatic artery.
to
Hepatic
artery
Narrowing
at of
168
more
RABY
than
70%
significant.
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and a Thomas signed
of the transverse
Hepatic
artery
catheter
for this purpose.
diameter
angioplasty
was
(Schneider,
London,
This is a 7-French
was
done
considered
with
a coaxial
to be
catheter
AL.
de-
that is introduced
into the femoral artery with a sheath. The sidewinder configuration formed at the aortic bifurcation because the catheter is too short
to
is
allow
be
AJR:157,
5-French vein.
balloon
U.K.), specifically
ET
sheath was inserted
A 5-mm
precurved
balloon
over a guidewire catheter
was
July
1991
into the donor portal
passed
coaxially
across
the stenosis and inflated. In one case, two balloons were used (Fig. 2) to obtain the necessary effective diameter in a large portal vein.
stenosis (Fig. 1). A satisfactory result after angioplasty was defined as reduction of the narrowing to no more than 30% of the arterial transverse diameter. Portal vein studies were indicated when evidence of raised portal venous pressure, manifested as variceal bleeding or splenomegaly, was detected clinically and sonographically. Further investigation consisted of measurement of hepatic wedge pressure and splenic pulp pressure. Hepatic wedge pressures were obtained by using cobra or sidewinder catheters with balloon occlusion of the hepatic
The pressure gradient across the stenosis was measured before and after inflation. A gradient across the stenosis of more than 5 mm Hg was considered abnormal, and reduction of the gradient to below this level after venoplasty was considered to indicate technical success. Patients were examined by venacavography because of bilateral lower limb edema. Pressure studies across the anastomoses in the inferior vena cava were obtained with a single end-hole catheter. Caval venoplasty was achieved via a right femoral vein approach. The stenosis was traversed with a guidewire, and a conventional balloon angioplasty catheter was inflated across the stenosis. The pressure gradient was measured before and after the procedure. A gradient of 1 0 mm Hg was considered to be abnormal, and reduction of the gradient to less than this was considered to indicate success.
vein.
All procedures
formation
in the aortic
arch.
Once formed,
the catheter
can
selectively to catheterize the common hepatic artery, thus allowing delivery of the balloon catheter coaxially at the site of used
Splenic
puncture
pulp
pressures
with a 23-gauge
these two measurements
were
needle.
measured
A difference
was taken
after
direct
splenic
as evidence
elsewhere
transhepatic
[1 ].
route
The portal vein was punctured
and catheterized
taking prophylactic
anti-
of a significant
pressure gradient across the stenosis that warranted venoplasty. A pressure gradient across the stenosis was confirmed during transhepatic balloon venoplasty. Portal venoplasty has been described in detail
were done with the patients
biotics.
of 5 mm Hg between
via an intercostal
with a fine-needle
introducer.
A
Results Anastomotic stenoses of the hepatic artery were fully dilated in three adult patients. These stenoses
successoccurred
---
) L
4
‘, A
Fig. 1.-Hepatic angiograms of 36-year-old man with deteriorating liver function. A, Anastomosis has 90% stenosis just distal to origin of gastroduodenal artery. B, Thomas guide catheter in common hepatic artery. A fine guidewire has been passed across stenosis. C, Balloon catheter passed coaxially through Thomas catheter and inflated across stenosis. D, After angioplasty, severity of anastomotic narrowing is markedly reduced to 30%.
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AJA:157,
July
1991
ANGIOPLASTY
OF
STENOSES
OF
VASCULAR
169
ANASTOMOSES
;
Fig. 2.-Angiograms of 6-year-old boy with anemia and splenomegaly. A, Aortoportogram shows anastomotic narrowing of portal vein (arrows). B, Transhepatic portal vein puncture confirms anastomotic stenosis (arrows) C, Two balloons inflated across stenosis. Pressure gradient measured when
at 1 0 days, 2 months, and 8 months after transplantation. All patients had abnormal liver function as evidenced by elevated levels of bilirubin and liver enzymes. These showed marked improvement after angioplasty. Repeated arteriography showed no evidence of stricture recurrence at 6 months in one patient who underwent a second transplantation shortly afterward because of vanishing bile duct syndrome. One patient reexamined on two occasions because of deterioration in liver function showed restenosis at 6 and 9 months after the initial procedure. On each occasion, the degree of stenosis, although still abnormal, was progressively less. Results of liver function tests became normal after each angioplasty. This patient remains well, with normal liver function 9 months after the last angioplasty. The third patient had an intrahepatic abscess and strictures of the common hepatic duct. These were managed by endoscopic placement of an 8-French biliary stent and percutaneous drainage of the abscess. Repeated arteriography at 4 and 8 months after angioplasty showed restenosis on each occasion, but these were also progressively less severe and were successfully redilated. Twelve months after initial presentation, the liver parenchyma and biliary tree are normal on sonographic examination, and the patient is well, with normal findings on liver function tests. Portal vein stenosis was diagnosed in three patients (two children aged 2 and 4 and one adult) 2, 4, and 5 years after transplantation, respectively. Gradients across the stenoses of 24 and 12 mm Hg in the children were reduced to 2 mm Hg after venoplasty. Both have reduction in splenomegaly on sonographic examination, and no evidence of variceal bleeding has been seen in 1 year of follow-up. The adult patient had a stenotic gradient of 1 4 mm Hg, which did not alter after venoplasty. Spleen size has not altered, however, and the patient has not had any episodes of variceal bleeding. Four cases of suprahepatic caval stenosis were encountered at 8 and 1 5 months in two cases and at 2.0 and 4.5
and allows direct measurement
of pressure gradient.
catheter
stenosis
was withdrawn
across
confirmed
reduction
of gradient.
years in the other two cases. In one case, caval thrombosis occurred 1 week after demonstration of the stenosis, and pressure studies were not obtained. In this case, despite intracaval streptokinase (Hoechst, Hounslow, U.K.) and subsequent surgical thrombectomy, the patient died as a result of recurrent caval thrombosis. The presence of a significant pressure gradient was confirmed in the three remaining cases. In one of these, venacavography showed reversed flow down the inferior vena cava, mimicking a caval thrombosis (Fig. 3). Superior venacavography from the arm showed a suprahepatic caval stenosis with reversed flow in the inferior vena cava, with the hepatic and renal veins decompressing retrogradely into the inferior vena cava and hemiazygous collaterals. After dilatation of the stenosis, flow within the inferior vena cava was in a normal direction and the pressure gradient was reduced from 24 to 6 mm Hg. Leg edema resolved after the procedure but recurred 9 months later. Recurrent stenosis confirmed by venacavography was treated by another balloon dilatation with a similar good result, which has been maintamed for a year. The other two patients remain free of symptoms 1 0 and 1 4 months after treatment.
Discussion Vascular complications of liver transplantation that can be corrected by nonsurgical methods are rare. The 1 0 cases described in this paper represent our experience with more than 600 transplantations. Hepatic artery occlusion in the immediate posttransplantation period requires urgent surgical intervention, usually retransplantation. In some patients, slowly progressive graft ischemia occurs, usually due to arterial thrombosis. In a few instances, however, ischemia is due to an anastomotic stenosis. The usual reason for examining these patients is the development of abnormal liver function; sonography is the primary method of examination. If biliary obstruction is ex-
170
RABY
ET
AL.
AJR:157,
Fig. 3.-Angiograms
of 25-year-old
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with edema in both legs. A and B, Anteroposterior
(A)
views of inferior venacavogram -C
of intrahepatic
a
cava,
July 1991
mimicking
woman
and lateral (B) show nonfilling thrombosis.
A
superior caval injection showed a suprahepatic caval anastomotic stenosis with retrograde flow in inferior
vena
cava
and hemiazygous
collater-
als. C, Balloon
dilatation
of caval stenosis. Note at site of stenosis. D, Postangioplasty appearance. Some residual stenosis persists (arrows), but pressure gre-
“waisting” of balloon (arrow)
dient is gone, and normal established.
direction
of flow re-
Lt A
cluded, a liver biopsy is performed and if the diagnosis is not clear cut, assessment of graft vascularization is indicated. Doppler sonography often can exclude occlusion of the hepatic artery and may suggest the presence of an arterial stenosis, but angiographic evidence is required for confirmation in such cases [2]. Additionally, the detection by sonography of focal areas of altered reflectivity within the hepatic parenchyma strongly suggests graft ischemia [2]. Attempts at treatment without ensuring that the graft is adequately vascularized are generally unsuccessful. lschemia also is regarded as a factor in the development of bile duct strictures [3], although the association is not as strong as with parenchymal abnormalities. One of our patients with arterial stenosis had both focal liver lesions and biliary stricturing in keeping with the above observations. Stenosis of the hepatic artery is uncommon, although occlusion is encountered more frequently [4]. Only four previous cases of percutaneous hepatic artery angioplasty have been described [4-6]. In two of these cases, a transfemoral approach failed and a brachial artery had to be used. This problem was overcome in our series by the use of a guide catheter specially developed for angioplasty of renal and hepatic transplants. The Thomas catheter allows
selective catheterization of the common hepatic artery and the subsequent passage of an angioplasty balloon through the guide catheter and across the stenosis. Although longterm experience is limited, it appears that, as with arterial stenoses encountered in the transplanted kidney, restenosis after angioplasty is highly probable. However, as in renal transplantation patients, repeated angioplasty of the stenosis may be beneficial [7] and ultimately may result in satisfactory long-term patency, as has occurred in two patients described here. To our knowledge, the use of percutaneous venoplasty of the portal vein after liver transplantation has not been described previously. According to Wozney et al. [4], significant portal vein stenosis is an uncommon complication after transplantation. Our experience agrees with that of Wozney et al., who noted that this complication usually occurs several years after transplantation and most often in children. Increasing spleen size and the development of varices with subsequent gastrointestinal hemorrhage and anemia are signs of this complication. Narrowing of the site of the portal vein anastomosis is seen commonly on real-time sonography [8], and Doppler studies often show turbulent flow at the anastomosis, but such abnormalities do not appear to be of functional
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AJA:157,
July
1991
ANGIOPLASTY
OF
STENOSES
significance. When patients are being considered for portal vein angioplasty, it is essential to confirm with pressure studies that the stenosis is hemodynamically significant by showing a pressure gradient across the stenosis. After a patent but narrowed portal vein is demonstrated, hepatic wedge pressure and direct splenic pulp pressure measurements enable patients with a significant gradient to be selected without traversing the graft parenchyma. Once a pressure gradient has been identified, it can be confirmed during transhepatic portal vein puncture. Stenosis of the suprahepatic caval anastomosis also is rare. Graft function is not impaired unless hepatic venous outflow is severely compromised; thus, caval stenosis manifests as lower limb edema. The diagnosis can be suggested by sonography, but angiographic confirmation with evidence of a significant pressure gradient must be obtained. Percutaneous dilatation is relatively straightforward, and in the three cases in which this was achieved, the symptoms have resolved. Repeated dilatation at 9 months was successful in one patient, and all three patients have had long-term relief of symptoms. The finding of a significant stenosis should be dealt with urgently, because in one patient a delay of 1 week after the initial diagnosis of stenosis resulted in the development of caval thrombosis proximal to the stenosis. The occurrence of acute caval thrombosis carries a very poor prognosis, with both thrombolytic therapy and surgery failing to prevent death in this case. The association of thrombus proximal to caval stenoses has been noted before [9]. In his series, Cardella et al. [9] noted several cases of caval thrombosis that extended into the hepatic veins. We have not encountered this complication. Figure 3 shows how abnormal flow in the inferior vena cava proximal to a stenosis may lead to nonopacification of blood in the inferior vena cava, thus leading to an erroneous diagnosis of thrombus formation. Venacavography from above and below the stenosis may be required to define the situation accurately. If a flow artifact is not recognized as such, thrombolytic therapy may be instituted needlessly. Other than the first case in this series, which has been previously reported [1 0], we are aware of only one other balloon dilatation of the suprahepatic caval anastomosis [11]. Rose et al. [12] reported the dilatation of an infrahepatic
OF
VASCULAR
caval
171
ANASTOMOSES
stenosis,
but we have
not seen
any examples
of this
complication.
With the improving survival rate of patients after liver transplantation, the number of patients with late complications of vascular anastomoses is likely to increase. The addition of successful nonsurgical measures to deal with these complications is therefore welcome. Long-term follow-up is, however, required to define fully the role of these techniques. Short-term technical success is achievable in most cases. The techniques described are safe, and the only significant complication has been sepsis after portal vein angioplasty. No serious sequelae occurred.
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2. Segel M, Zajko A, Delbert A, Bron K, Skolnick M, Starzl T. Hepatic artery thrombosis after liver transplantation. AJR 1986:146: 137-1 41 3. Zajko A, Campbell W, Logsdon G, et al. Cholangiographic findings in hepatic
artery
occlusion
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liver
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8. Raby N, Meire H, Forbes A, Williams A. The role of ultrasound scanning in management after liver transplantation. Clin Radiol 1988:39:507-510 9. Cardella JF, Castaheda-Z#{252}#{241}iga WF, Hunter D, Young A, Amplatz K. Angiographic and interventional tation. AJR i986;146:143-153
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