Abstract No. 574 Understanding the liver abscess microbiome: outcomes of percutaneous liver parenchymal abscess drainage with microbiologic correlation

Abstract

The purpose of this study is to review the outcomes of percutaneous liver abscess drainage and correlate with abscess microbiology. Single-institution quality database (Hi-IQ) was used for retrospective identification of percutaneous liver abscess drainage cases between January 1, 2010, and January 1, 2020. Manual review of the clinical and imaging record was performed to identify outcomes and laboratory data. Student t-test was used to correlate outcomes with microbiology data. 172 liver abscess drainages were performed on 161 patients: 60 females and 101 males. Mean patient age was 57 years (range, 16–90). Mean drain dwell time was 5 weeks (range, 1–71 weeks). Median drain size was 12 French (range, 8–16F). 132 (77%) of the abscesses were in the right lobe. Aspiration alone was performed in 2 cases. Technical success, defined as positioning catheter tip into the liver abscess and obtaining a sample, was 98%. Most common post-procedural complications included 12 biliary tree fistulas (7%) and 6 empyemas (3%). Follow-up until tube removal or death was available for 164 (97%). Drainage catheters were removed due to resolution of the abscess cavity in 67% (110/164), present at demise in 20% (32/164), removed at surgery in 10% (16/164), accidental removal in 3% (5/164), or removed due to tube malfunction in 0.6% (1/164). 84% of cases had available culture data. 109 (77%) demonstrated microbial growth, of which 50% were polymicrobial. Microbial speciation from percutaneous sample changed antibiotic management in 76% (84/109). Percutaneous drainage identified species and sensitivities in 72% of cases with negative blood cultures, suggesting percutaneous abscess drainage is more sensitive. Resolution of the abscess cavity correlated with infection from Klebsiella (P < 0.05) and Enterococcus (P < 0.01). Both tube malfunction and accidental removal correlated with infection from Bacteroides (P < 0.05). Tube removal at surgery correlated with infection from Klebsiella (<0.01) and Enterobacter (P < 0.05). Death or hospice admission correlated with infection from Enterobacter (P < 0.05) and Enterococcus (P < 0.005). Biliary fistulas correlated with infection from Enterobacter (P < 0.005). Percutaneous drainage is safe and effective for liver abscess management and provides sampling for proper bacterial speciation and antibiotic sensitivity testing which is imperative for proper antibiotic treatment selection. Bacterial speciation and sensitivities correlate with drainage outcomes and complications and can inform long-term management decisions.