EP781 - Determination of predictors in colorectal patients associated with abdominal IR drain upsize

Purpose/Background: Intra-abdominal fluid collections are common in patients who have colorectal pathology such as diverticulitis, inflammatory bowel disease, or following a colorectal surgery. These fluid collections are often treated with percutaneous drainage by Interventional Radiology. In clinical practice, initial drain placement is frequently inadequate, and subsequent drain upsizing or repositioning is needed to resolve the fluid collection, leading to increased hospital stays. Factors that could be used to predict when initial drain placement will be successful are unknown. Therefore, the aim of this study was to (1) determine how frequently subsequent IR procedures are needed after initial drain placement to treat an intra-abdominal fluid collection, and (2) determine if any factors are associated with the need for subsequent procedures.

Methods/Interventions: We performed a retrospective chart review of consecutive patients who were admitted to the colorectal surgery service at a tertiary care academic center who underwent IR drainage of an intra-abdominal fluid collection from August 2022 to June 2025. Patients were included if they were at least 18 years old and admitted for treatment of a colorectal pathology. Patient demographics, drain and fluid characteristics, and treatment outcomes were abstracted from the electronic medical record. Univariate and multivariate statistical analysis were performed.

Results/Outcomes: 121 patients met the inclusion criteria and made up the study cohort. This cohort had a mean age of 58 years (IQR: 40-68) and 57% were female (n = 69). Seventy-three (60.3%) patients received their drain to treat a post-operative fluid collection, whereas 48 patients (39.7%) had a drain to treat a fluid collection that was not associated with a surgery. The most common diagnosis for the postoperative patients was malignancy (41.1%) followed by IBD (27.4%), whereas the most common diagnosis for the non-operative cohort was diverticulitis (41.7%) followed by IBD (35.4%). For the initial drain placement, 49.6% (n = 60) of the patients had an 8.5 Fr drain placed, the median of the largest diameter of fluid collection was 7.2 cm (IQR: 5.5, 10.0), and the fluid characterization of the majority of patients (n = 64, 52.9%) was described as purulent.

Of the entire cohort, 38% of patients (n = 46) required a second IR drain intervention. Of these secondary procedures, 54.3% (n=25) was for a drain upsize , 23.9% (n = 11) was for an additional drain, and 21.7% (n=10) was for a drain reposition. Univariate analysis found no difference in demographic factors such as diagnosis, BMI, immunosuppression, prior surgical history between patients that needed a secondary IR procedure vs those that did not. Similarly, there were no differences in fluid collection factors such as size, fluid character, or size of the initial drain. Multivariate modeling found no factors that were independently associated with the need for a second IR procedure.

Conclusion/Discussion: Nearly 40% of patients who received an IR drain for treatment of a colorectal-related fluid collection required a secondary IR drain procedure. Surprisingly, we were unable to identify any demographic or fluid related factors that were associated with the failure of initial drain placement.