Complications following biopsy of an intraabdominal or retroperitoneal mass compared with a renal mass.

Introduction: This study aimed to assess the short-term complication rate after US-guided core needle biopsies with an 18-gauge needle of retroperitoneal or intraabdominal masses (non-kidney group) compared with complications after biopsy from a renal mass (kidney group).
Methods: This was a retrospective analysis of 330 consecutive patients in the non-kidney group and 330 control patients in the kidney group. We recorded baseline characteristics, diagnostic yield, complications graded as Clavien-Dindo (CD) and readmissions within one and seven days.
Results: In all, 245 patients in the non-kidney and 281 patients in the kidney group had a biopsy performed. A total of 54 (22%) patients in the non-kidney group had a complication registered. However, 47 were minor complications (minor bleeding or localised pain, CD 1). In the kidney group, 47 (17%) patients had a complication, with 44 being graded as CD 1. No major complications (CD 3 or higher) were associated with the biopsies. Only 0.8% of patients in the non-kidney group and 0.7% in the kidney group had a treatment-requiring CD 2 complication (i.e. blood transfusion) directly caused by the US-guided biopsy. These complications were recognised less than 30 minutes or more than four hours after the procedure. We found no significant difference in the complication rate, diagnostic yield or risk of re-admission between the two groups.
Conclusion: The observation period for patients who undergo an uncomplicated US-guided biopsy from an intraabdominal or retroperitoneal mass can safely be reduced to 30 minutes.
Funding: None TRIAL REGISTRATION. Not relevant.
(Published under Open Access CC-BY-NC-BD 4.0. https://creativecommons.org/licenses/by-nc-nd/4.0/.)