Reply to Letter to the Editor: Targeted and non-targeted liver biopsies actually carry the same risk of ‘severe complication’

by Maxime Ronot, Anna Maheux, Valérie Vilgrain (maxime.ronot@aphp.fr)

Targeted and non-targeted liver biopsies carry the same risk of complication

We thank our esteemed colleagues for their valuable comment. Our study aimed at reappraising the rate of and the risk factors for complications of percutaneous ultrasound-guided liver biopsy, comparing targeted and non-targeted biopsies [1]. We concluded that, overall, ultrasound-guided percutaneous liver biopsy is a safe procedure with a low rate of complications, which has been reported many times in literature. We also confirmed the importance of coagulation parameters. Noticeably, we stressed the influence of a high creatinine serum level on the risk of bleeding that is frequently underestimated. Interestingly, we also showed that, in targeted biopsies, larger tumors have a higher risk of complications, but lesions showing hyperenhancement on arterial phase imaging do not. We believe these findings were undebated by our colleagues.

Our point of disagreement appears to be terminological, and lies in the definition of “complication” we used in our study. This is indeed very important. In our study, any untoward medical occurrence following liver biopsy was defined as ‘advert event’. Our main concern was that most common indication for post-biopsy imaging was pain only. To compensate for the retrospective design of the study, lacking a standardized and prospective recollection of all symptoms, we used the need for any complementary imaging (ultrasound or CT) as “objective” criterion for selecting ‘marked symptoms’. We reserved the term ‘complication’ to any abnormality on post-biopsy imaging considered imputable to biopsy.

We fully understand how this may mislead the readers. The available published literature is not consensual as to which classification of adverse events should be used. Yet, aiming at consensual terminology is indeed important. In retrospect, and to avoid misunderstanding, we should have used the term ‘mild adverse event’ instead of ‘marked symptom’ [2]. Therefore, we could have concluded that “even if targeted biopsies expose to a higher risk of mild adverse events, targeted and non-targeted liver biopsies actually carry the same risk of severe complication.”