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.

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.