A retrospective study on the safety of small and large volume paracentesis and risk factors for adverse events in patients with gastrointestinal cancer with malignant ascites.

Abstract

Background: The optimal drainage volume for paracentesis in malignant ascites (MA) has not been established, and identifying risk factors for paracentesis may serve as a guideline for clinical decisions regarding drainage volume in MA patients. Therefore, the aim of this study is to compare the safety of small-volume drainage (SVD) versus large-volume drainage (LVD) in MA patients and to identify risk factors for adverse events (AEs).

Methods: This single-center retrospective study analyzed gastrointestinal cancer patients who underwent paracentesis between 2014 and 2023. Patients were categorized into SVD (<3,000 mL) and LVD (≥3,000 mL) groups. The primary endpoint was the incidence of paracentesis-related AEs, including hypotension, infection, renal dysfunction, and hyponatremia. Multivariate logistic regression was used to identify independent risk factors for AEs.

Results: Among 89 eligible patients, 58 received SVD and 31 received LVD. The incidence of AEs was significantly higher in the LVD group compared to the SVD group (41.9% vs. 20.7%, P=0.04), particularly for hypotension (12.9% vs. 1.7%, P=0.04). In multivariate analysis, serum albumin <2.5 g/dL [odds ratio (OR) 3.20; 95% confidence interval (CI): 1.06-9.64] and LVD (OR 3.45; 95% CI: 1.20-9.93) were identified as independent risk factors for AEs. There was no significant difference in overall survival (OS; P=0.86) or the interval to subsequent paracentesis (P=0.21) between the groups.

Conclusions: Large-volume paracentesis was associated with a higher risk of AEs without additional efficacy in terms of symptom control. SVD appears to be a safer and equally effective option, especially for patients with low serum albumin. These findings support a conservative and individualized approach to fluid removal in patients with MA.