Significance of Postprocedural Contrast Medium Injection after CT-Guided Abscess Drainage

Abstract

The aim was to evaluate the additive clinical value of an additional post-procedural control-scan after CT-guided percutaneous abscess drainage (PAD) placement with contrast medium (CM) via the newly placed drain. All CT-guided PADs during a 33-month period were retrospectively analyzed. We analyzed two subgroups, containing patients with and without surgery before intervention. Additionally, radiological records were reevaluated, concerning severe inflammatory response syndrome (SIRS) during the intervention. A total of 499 drainages were placed under CT-guidance in 352 patients. A total of 197 drainages were flushed with CM directly after the intervention, and 51 (26%) showed an additional significant finding. An immediate change of therapy was found in 19 cases (9%). The subgroup that underwent surgery (120 CM-drainages; 32 (27%) additional findings; 13 (11%) immediate changes of therapy) showed no statistically significant difference compared to the subgroup without surgery (77 CM-drainages; 19 (25%) additional findings; 5 (6%) immediate changes of therapy). SIRS occurred in 2 of the 197 flushed drainages (1%) after CM application. An additional scan with CM injection via the newly placed drain revealed clinically significant additional information in almost 26% of the drainages reviewed in this study. In 9% of the cases this information led to an immediate change of therapy. Risks for SIRS are low.

Keywords: computed tomography; drain; intervention; post-surgical complications; systemic inflammatory response syndrome (SIRS).

Figure 1

Patient selection over a 33-month period. Patients with drainages flushed with diluted contrast medium (CM) were selected for further evaluation.

Figure 2

Patient with necrotizing pancreatitis and drainage of the fluid collection in the former region of the spleen. The post-procedural CM-flush showed CM in the gastric cavum (arrow), which did not result in a change of therapy (additional imaging finding).

Figure 3

Patient with bilioma after Whipple procedure. The injected CM led to contrast in the common biliary duct (arrow). That proved an insufficient bilio-digestive anastomosis, leading to PTBD as an immediate change of therapy.

Figure 4

Patient with necrotizing pancreatitis. After CM injection via the newly placed drain, a fistula to the descending colon (arrow) was proven. The patient subsequently underwent right hemicolectomy.