Letter regarding “Complications following biopsy of an intra-abdominal or retroperitoneal mass compared with a renal mass”

I read the article “Complications following biopsy of an intra-abdominal or retroperitoneal mass compared with a renal mass” by Katrine Schou-Jensen, published in the Danish Medical Journal [1]. The study examines whether the observation period after an ultrasound-guided core needle biopsy (CNB) for intra-abdominal or retroperitoneal masses can be safely reduced from four hours to 30 minutes, as used for kidney biopsies. By comparing complication and readmission rates in 245 non-kidney biopsy patients and 281 kidney biopsy patients, the study found no significant rise in major complications or readmissions, suggesting that reducing observation time could be safe and cost-effective.

Although the author Schou-Jensen has done a meticulous job. However, this research could be strengthened by stratifying patients based on the biopsy site. Certain organs, like the liver and spleen, carry higher bleeding risks due to their vascularity, suggesting that a “one-size-fits-all” observation period may not be optimal. Analyzing site-specific risks could enhance safety and efficiency. Expanding the study to multiple institutions would increase generalizability. A multicenter study could minimize bias and offer robust conclusions, similar to other studies on CNB complication rates.

Studies show that certain intra-abdominal organs exhibit different post-biopsy risk levels. The major complication rate was 21%, with 84.6% due to procedural site pain, while other major complications occurred in 1.6% of cases. Only 1% of biopsies required post-procedural hospitalization, with no deaths reported [2]. Similarly, 48.5% of female patients underwent splenic biopsy with an 18-gauge or smaller needle, and 47.5% with a larger than 18gauge needle. Bleeding was observed in 8.4% of patients in the 18-gauge or smaller group and 7.9% in the larger group [3]. These findings suggest that a uniform reduction in observation time may not suit all biopsy sites. Contradicting Schou-Jensen's findings, other studies on CNB observed reduced complications with prolonged observation, especially for highly vascular organs. Complications after RMB typically occur within three or after 24 hours, supporting a 3-hour monitoring window for safe patient management [4]. Kidney biopsy studies confirm the feasibility of shorter OT, with 18-gauge needles lowering complication risks and obtaining adequate tissue [5].

These studies suggest that reducing observation time may be feasible for certain masses but high-risk biopsies, such as those of the liver or spleen, may require extended observation to prevent complications. Integrating these findings into Schou-Jensen’s study would provide a more detailed understanding of post-biopsy care and support differentiated observation protocols based on the specific risks associated with each type of intraabdominal biopsy.