Complications Following Irinotecan-Loaded Microsphere Chemoembolization of Colorectal Metastatic Liver Lesions Associated with Hepatic-Artery Branch Temporary Stasis

Chemoembolization with irinotecan-loaded microspheres has proven effective in the treatment of unresectable liver metastases in the course of colorectal cancer (CRC). Most researchers recommend slowly administering the embolizate at the level of the lobar arteries, without obtaining visible stasis. However, there are reports of a relationship between postoperative embolizate retention in metastatic lesions and the response to treatment. To retain residual embolizate throughout the entire neoplastic lesion requires a temporary flow stop (stasis) within all supply vessels, which may cause temporary stasis in subsegmental or even segmental vessels. Objective: To assess the risk of complications and post-embolization syndrome severity following chemoembolization of CRC metastatic liver lesions with microspheres loaded with Irinotecan, with regard to hepatic-artery branch level of temporary stasis. Patients and methods: The study included 52 patients (29 female, 23 male) with liver metastases from CRC, who underwent 202 chemoembolization treatments (mean: 3.88 per patient) with microspheres loaded with 100 mg irinotecan. Postembolization syndrome (PES) severity and complication occurrence were assessed with regard to the hepatic-artery branch level of temporary stasis. Adverse events were assessed according to Cancer Therapy Evaluation Program Common Terminology Criteria for Adverse Events. Results: Median survival from the start of chemoembolization was 13 months. From 202 chemoembolization sessions, 15 (7.4%) significant complications were found. The study found a significant relationship between the branch level of temporary stasis and the presence of complications (p < 0.001), with the highest number of complications observed with temporary stasis in segmental vessels. PES was diagnosed after 103 (51%) chemoembolization treatments. A significant association was found between PES severity and the branch level of temporary stasis (p < 0.001). Conclusions: The branch level of temporary stasis affected the severity of post-embolization syndrome. A significant association was found between the branch level of temporary stasis obtained in chemoembolization procedures and the presence of complications. The apparent lack of change in numbers of complications when stasis was applied at tumor supply vessels or subsegmental arteries may indicate the safe use of temporary stasis in some cases where colorectal cancer metastases are treated. Further research is needed to determine the most effective chemoembolization technique.