Interventional procedures

One of the commonest and important interventional techniques is guided fine-needle biopsy which is most easily performed under US-contral (Fig. 19). Needle biopsies are important, since neither focal nor diffuse liver disease necessarily exhibit diagnostic features on imaging. In some disorders a cutting needle biopsy is required and in patients with abnormal coagulation parameters this is most safely obtained using either the transjugular approach or a percutaneous technique with embolization of the biopsy track after obtaining the specimen.

The drainage of liver abscesses or sub-phrenic abscesses is another important interventional technique that has greatly reduced the need for

Figure 19. US guidance of fine needle biopsy. A percutaneous fine needle biopsy of a liver tumour is demonstrated, showing the echo from the needle (curved arrows) within the tumour (between straight arrows). Normal liver parenchyma (L) is seen to the left.

Liver tumours may be treated by embolization or direct ethanol injection. Both methods are under investigation. Embolization can be particularly useful in the palliative treatment of functioning endocrine metastases in the liver. Hepatic bleeding from trauma, biopsy, aneurysm or other causes is often most effectively treated by embolization. In institutions with the requisite interventional expertise, embolization is the treatment method of first choice for most types of hepato-biliary haemorrhage.

here are a number of interventional procedures such as percutaneous transhepatic portography and percutaneous transhepatic cholangiography that use the liver as the most suitable access point. Through these routes a number of interventional procedures may be performed, described elsewhere in this book. Another important new technique is that of percutaneous porto-systemic shunting (TIPPS).

David J. Allison and Carl-Gustaf Standertskjold-Nordenstam