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PATHOLOGY OF THE LIVER AND PORTAL VENOUS SYSTEM 103
E
Paraumbilical
RPV
LPV
Oesophageal
Gastric
F
Figure 4.22 cont’d (E) The para-umbilical vein
culminates in a caput medusae just beneath the
umbilicus. (F) Varices can be seen around the gallbladder
wall in a case of hepatic fibrosis with portal
hypertension. (G) Collaterals in portal hypertension
(schematic representation).
Periportal
& duodenal
SMV
Spleno-renal
Caput
medusae
Ano-rectal
G
Contrast angiography with arterioportography is
considered to be the gold standard for assessing portal
vein patency, but this technique is time-consuming
and invasive and has similar results to carefully
performed ultrasound. 23
Ascites This is a transudate from the serosal
surfaces of the gut, peritoneum and liver.
Splenomegaly This is the result of backpressure
in the portal and splenic veins. The spleen
can enlarge to six times its normal size.
Varices (Fig. 4.22) These are venous anastomoses
from the high-pressure portal system to the
lower-pressure systemic circulation, which shunts
the blood away from the portal system. These vessels
have thinner walls than normal vessels, which
makes them prone to bleeding.
The common sites are:
● Gastric and lower oesophagus Oesophageal
varices are particularly prone to bleeding and
this is often the patient’s presenting symptom.
They are difficult to see on abdominal
ultrasound because of overlying stomach and
are better demonstrated with endoscopic
techniques. Left coronal scans may
demonstrate tortuous vessels at the medial
aspect of the upper pole of the spleen.
● Spleno-renal An anastomosis between the splenic
and left renal veins which is often seen on
ultrasound as a large, tortuous vessel at the
lower edge of the spleen (Fig. 4.22B, C).
(These anastomoses are usually very efficient at