ULTRASOUND GUIDED BIOPSY COMPLICATIONS

Complications of ultrasound-guided biopsy
Postprocedure complications such as haematoma requiring blood transfusion and trauma to adjacent viscera occur very infrequently when ultrasound guidance is used. As expected, the risk of complications is less in fine-needle biopsy than with larger needles; however, there is no significant difference in complication rate between a standard 18G Tru- Cut needle and a 22G Chiba needle. The mortality and major complication rates vary but using a standard 18G needle these are approximately 0.018–0.038% and 0.18–0.187% respectively, mortality being due to haemorrhage in 70%.

As a working figure this means the mortality is approximately 1 in 3300–5400 and morbidity 1 in 530 biopsies. The risk of haemorrhage is increased in patients with coexistent cirrhosis and is more likely to occur with malignant than benign lesions, although large haemangiomas also can carry a significant risk of bleeding. As with any procedure of this nature, there is a very small risk of infection, which can be minimized by using an aseptic technique.

Tumour seeding of the biopsy tract is an uncommon complication of biopsy and reports of tumour seeding are associated with repeated passes into the mass using large needles. Although much talked about, tumour track seeding is in fact rare, occurring in approximately 1 in 20 000 biopsies. The bestknown tumours for this are mesothelioma and hepatoma.

Complications following abdominal biopsy are increased with multiple passes and are at least in part related to the skill and experience of the operator. If the biopsy result is negative or unexpected then a number of scenarios should be considered and include sampling error, poor histological specimen, sonographic or pathological misinterpretation or indeed a true negative finding. A repeat biopsy is sometimes justified.