Incidence and evolution of venous thrombosis during the first 3 months after irreversible electroporation of malignant hepatic tumours.

The incidence and evolution of venous thrombosis adjacent to the ablation zone after percutaneous irreversible electroporation (IRE) were evaluated to identify potential risk factors in patients with hepatic malignancies. 205 venous structures (in 87 patients) within a ≤1.0 cm radius of the ablation zone were assessed after IRE of 112 hepatic lesions (74 primary, 38 secondary hepatic malignancies) by pre-interventional and post-interventional (1-3 days, 6 weeks and 3 months after IRE) contrast-enhanced magnetic resonance imaging. The relationships between venous thrombosis and clinical features were analysed using a binary logistic regression model. In 27 of 87 patients (31%), a total of 67 venous complications were noted during the 3 months follow-up. Thrombosis represented the most frequently observed complication (n = 47; 70.1%), followed by vessel narrowing (n = 20; 29.9%). 5 (10.6%) of 47 thromboses showed spontaneous regression 3 months after IRE. A small vessel diameter (p = 0.011) and post-interventional vessel narrowing (p = 0.006) were independently associated with delayed post-ablative thrombosis. Delayed venous thrombosis frequently occurs after IRE of hepatic malignancies. Pre-existing vessel narrowing and a small vessel diameter represent significant risk factors that require further surveillance and potentially therapeutic intervention.

Quantitative perfusion analysis of hepatocellular carcinoma using dynamic contrast enhanced ultrasound (CEUS) to determine tumor microvascularization.

OBJECTIVE: The use of a standardized dynamic contrast enhanced ultrasound (CEUS) protocol to determine perfusion of hepatocellular carcinomas (HCC) using quantitative analysis. METHODS: Retrospective analysis of 27 patients with hepatocellular carcinoma examined by a standardized protocol (bolus injection of 2.4 ml sulphur hexafluoride microbubbles, arterial phase to portal venous phase using continuous CINE-loops over 1 minute, short CINE-loops after 2, 3, 4, 5 and 6 minutes and additional single images for B-mode, CCDS). The examination was performed by an experienced sonographer with a high resolution, multi-frequency transducer (1-6 MHz). The reading of the reference imaging (contrast enhanced CT and MRI) and histopathology, if necessary, was performed independently. Retrospective analysis of the CEUS DICOM loops was done using time intensity curve analysis (TIC) with evaluation of the time to peak (TTP) and the area under the curve (AUC). RESULTS: All tumor lesions were characterized by CEUS, based on typical contrast patterns for HCC lesions with arterial enhancement and wash out in the late phase, corresponding to MRI with liver specific contrast agent or contrast enhanced CT. Mean TTP (SD) in the tumor centre (C) was 19.93 (11.31), in the periphery (P) 22.94 (9.44) and in the normal liver tissue (LT) 28.19 (11.34) with significant differences between all zones C/P (p = 0.013), C/LT (p = 0.005) and P/LT (p = 0.022). AUC mean (SD) in the tumor centre (C) was 660.03 (292.64), in the periphery (P) 586.04 (237.01) and in the normal liver tissue (LT) 484.20 (236.99), also with significant differences between all zones C/P (p = 0.001), C/LT (p < 0.001) and P/LT (p < 0.001). CONCLUSION: TIC-analysis is an easy-to-use tool for the dynamic evaluation of microvascularization in hepatocellular carcinoma and allows a fast and cost-efficient quantitative analysis.

Stereotactically navigated percutaneous microwave ablation (MWA) compared to conventional MWA: a matched pair analysis.

PURPOSE: To compare CT-navigated stereotactic microwave ablation (SMWA) to non-navigated conventional MWA (CMWA) for percutaneous ablation of liver malignancies. METHODS: A matched pair analysis of 36 patients who underwent MWA of primary or secondary liver malignancies (10 hepatocellular carcinoma and 8 metastases) was conducted. A total of 18 patients undergoing SMWA were included in this prospective study. Patients were matched in terms of tumor size, liver segment and entity to retrospective CMWA procedures. The endpoints were procedure time, accuracy of needle placement, technical success rate, complication rate and dose-length product (DLP). RESULTS: The procedure durations were 23.9 min (SD 3.7) for CMWA and 21.8 min (SD 16.3) for SMWA (p = 0.22). The procedural accuracy for SMWA and CMWA was identical for both groups (3.7 mm). The total DLP was significantly lower for SMWA than for CMWA (2115 mGy cm (SD 276) vs. 3109 mGy cm (SD 1137), respectively; p < 0.01). Complete ablation without residual tumor was observed in 94% (17 of 18) of SMWA and in 83% (15 of 18) of CMWA patients (p = 0.31). No complications occurred. CONCLUSIONS: SMWA is highly accurate and reduces the radiation dose without increasing the procedure time.