A 56-year-old healthy male patient presents to the emergency room because he has been experiencing left-sided abdominal pain for the past 4 days. He reports localized tenderness on examination. Screening colonoscopy performed 3 years prior was normal. His vital signs are 98% SpO₂, heart rate of 112, blood pressure of 120/76, and respiratory rate of 14. White blood cell count is 16, and other lab results are normal. You obtain a computed tomography (CT) of the abdomen and pelvis, which shows the following abcesses:

He was placed on IV antibiotics but failed to progress. Interventional radiology is unable to safely place a drain. What is the best next step?