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ABDOMINAL ULTRASOUND
Figure 4.32 The site of anastomosis in the IVC in a
liver transplant.
Figure 4.33
An area of infarction in a liver transplant.
The common bile duct
This should be carefully monitored postoperatively.
A measurement serves as a baseline from
which to detect small degrees of dilatation which
may imply stenosis or obstruction. Even relatively
minor dilatation can be significant in the transplant
patient; cholestasis can precipitate ascending biliary
infection which may subsequently form liver
abscesses, a process which may be aggravated by
immunosuppression.
Biliary complications occur in up to 15% of transplants
and most biliary complications become evident
during the first 3 months, although late
stenosis can occur after this. Strictures commonly
occur at the anastomosis due to scar tissue, but
other, non-anastomotic strictures can result from
hepatic artery insufficiency causing ischaemia.
Leakage is a comparatively rare event.
Focal lesions
Focal lesions within the parenchyma of the transplant
liver are usually a poor prognostic indicator.
Hepatic abscesses may be multiple and are often
acoustically subtle in the early stages, with echo
patterns closely similar to normal liver tissue.
Other causes of focal lesions in the early postoperative
period may be due to infarction and are associated
with interruption of the arterial supply.
These can be hyper- or hypoechoic, have welldefined
borders and do not exert a mass effect
(Fig. 4.33).
The longer the interval between removing and
transplanting the donor liver, the greater the likelihood
of ischaemic patches forming.
In patients who have been transplanted following
cirrhosis with malignancy, recurrence of HCC
may also be a serious complication.
Post-transplant lymphoproliferative disorder
may also demonstrate hypoechoic focal lesions
within the liver, occasionally also involving the
spleen and kidneys.
Fluid collections
These can frequently be demonstrated and monitored
with ultrasound. These may represent
haematoma (Fig. 4.34), seroma, loculated ascites
or biloma. It is not possible to differentiate different
types of collection with ultrasound alone. The
appearances are taken in conjunction with the clinical
features and the role of ultrasound is primarily
to monitor the gradual resolution of the collection.
It is important to determine if a collection is
infected in a clinically ill patient. This cannot be