Reply to letter regarding “Complications following biopsy of an intraabdominal or retroperitoneal mass compared with a renal mass”

We thank Dr. Basit and colleagues for their interest and appreciate the thoughtful comments [1] on our study evaluating observation times following ultrasound-guided core needle biopsy (CNB) of intra-abdominal and retroperitoneal masses compared to renal masses [2]. The suggestion to stratify by biopsy site is well taken; however, in our study, we had only one patient who underwent an 18-gauge needle biopsy of the spleen, making meaningful subgroup analysis in this regard unfeasible. Nonetheless, more than half of the biopsies in the non-kidney group (142 out of 245, 58%) were from the liver and none of these patients experienced a major complication. This aligns with findings from other studies suggesting that a short observation period is both safe and cost-effective for patients undergoing liver biopsies [3,4].

While a site-specific risk analysis could refine safety protocols, our data showed that most complications were minor (Clavien-Dindo grade 1), with less than one percent requiring treatment. Furthermore, all major complications were recognized either within 30 minutes or beyond four hours from the time of biopsy, supporting the case for reducing the observation period for most patients.

The idea of a multicenter study to enhance generalizability is desirable. Such research could provide a larger dataset for subgroup analyses based on organ type, anticoagulation status, and biopsy technique. We agree that tailored observation protocols could improve patient care and cost-effectiveness. However, our data support a reduced observation time in clinical settings where comprehensive pre-biopsy evaluations are standard practice.

Again, we thank Dr. Basit and colleagues for their insightful comments and hope this response clarifies our findings.