'Tru-Cut' needle biopsy of the liver: importance of the correct technique.

In order to determine which technique would provide adequate tissue for histological examination when the 'Tru-Cut' needle is used for liver biopsy, the livers of cadavers were biopsied by a single operator, under direct vision, using a 'Tru-Cut' needle. The modified breast biopsy technique either preceded or followed one of two alternative methods, one of which was recommended by the manufacturer, in a random manner. Thereafter, the biopsies were repeated using the alternative sequence. The mean length of the liver biopsy specimens that were obtained using the modified breast biopsy technique was 16.3 mm (range: 8-20 mm). The corresponding figures for the manufacturerer's method were 7.7 mm (range: 2-14 mm) and for the third technique were 2.7 mm (range: 0.5-8 mm). Three of the 40 specimens (7.5%) obtained using the latter technique fragmented when placed in formalin; this did not occur in any of the 40 specimens taken using the modified breast biopsy technique. This investigation indicates that the modified breast biopsy technique should be used when 'Tru-Cut' needle biopsy of the liver is performed. This provides specimens which are adequate for histological diagnosis. In addition, the safety of liver biopsy, which is compromised by poor technique, is improved. The alternative methods, including that recommended by the manufacturer, must be avoided.