Safety of CT-Guided Microwave Ablation of Subcardiac Liver Tumors

PURPOSE

The purpose of this study was to investigate the safety of CT-guided microwave ablation (MWA) of subcardiac hepatic tumors.

MATERIALS AND METHODS

This retrospective study included 19 patients (11 males and 8 females, age: 64.0 years (IQR: 58.3, 71.0) who underwent CT-guided MWA of 22 subcardiac tumors from January 2016 through December 2020. The subcardiac tumors consisted of 6 hepatocellular carcinomas and 16 metastases. Hydrodissection or other thermal protection technique was not used during the ablation. Subcardiac ablation was defined as the ablation zone extended ≤ 0.5 cm from myocardium or coronary artery. The safety of MWA of subcardiac tumors was evaluated based on procedural and post-procedural complications and intra-procedural ECG changes. Local tumor progression (LTP) was also analyzed and correlated with tumor and ablation zone sizes.

RESULTS

The primary efficacy rate was 100%. The median follow-up was 20.5 months (IQR: 6.0, 29.8). There was no 30-day mortality. One grade 3 complication occurred (severe shoulder and chest pain), and there were 19 events of grade 1 or 2 complications. No instances of cardiac complications or significant procedural ECG changes were observed. There were 22 events of grade 1 and 2 laboratory toxicity and 1 event of grade 3 elevated bilirubin. The LTP was 13.6% at 1 year and 22.7% at 2 years. There was no significant correlation between LTP and tumor or ablation zone sizes.

CONCLUSION

CT-guided MWA of subcardiac hepatic tumors is safe, and MWA should be considered as an option for managing subcardiac tumors. LTP rates for MWA of subcardiac tumors may be inferior to ablation of tumors in common location.

LEVEL OF EVIDENCE III

Cohort Study.

[The therapeutic outcomes of ultrasound-guided percutaneous radiofrequency therapy for subcardiac liver malignant tumor]

Objective: To examine the safety and effectiveness of ultrasound-guided percutaneous radiofrequency ablation in the treatment of liver malignant tumor under subcardiac. Methods: The clinical data of 26 patients (31 tumors) with subcardiac liver malignant tumors who underwent ultrasound-guided percutaneous radiofrequency ablation from January 2017 to October 2019 at the Affiliated Tumor Hospital of Zhengzhou University were retrospectively analyzed. There were 21 males and 5 females. The age was 55 years old (range: 40 to 77 years old) .There were 14 cases of primary liver cancer and 12 cases of metastatic liver cancer. The maximum diameter of tumor was (2.3±1.0) cm (range: 1.0 to 4.2 cm) .According to the maximum diameter of the tumor, 1∶1 match was made between 27 non-subcardiac patients admitted at the same time and a total of 36 liver malignant tumors. subcardiac tumor is defined as tumor ≤1 cm from pericardium in sagittal or coronal imaging. The ablation effect and complications were recorded, and the one-time complete ablation rate, main technical efficiency and complications were evaluated. The preoperative baseline characteristics, ablation effect and complications of the two groups of patients were collected and counted. Single factor analysis and Logistic regression analysis were used to analyze the independent risk factors that affect the ablation effect of ultrasound-guided percutaneous radiofrequency ablation for liver malignant tumors under subcardiac. Results: The one-time complete ablation rate of tumor after radiofrequency ablation was 80.8% (21/26) in the subcardiac group and 92.6% (25/27) in the non-subcardiac group. There was no significant difference between the two groups (P>0.05) . No evidence of local tumor progression was found in the follow-up evaluation of the two groups one month after radiofrequency ablation, and the main technical effective rate was 100%.Ablation-related complications occurred in 2 patients in the subcardiac group. Multivariate analysis both showed that the distance between tumor margin and pericardium ≤5 mm was an independent risk factor affecting radiofrequency ablation (OR=0.020, 95%CI: 0.001 to 0.454, P=0.014) . Conclusions: Ultrasound-guided percutaneous radiofrequency ablation can safely and effectively treat liver malignant tumor under subcardiac. When there is a tumor near the patient's heart (the distance between the edge of the tumor and pericardium is ≤5 mm) , special attention should be paid to formulate a detailed and reasonable ablation plan to minimize tumor residue.