Adjunctive hydrodissection of the bare area of liver during percutaneous thermal ablation of sub-cardiac hepatic tumours

Application and evaluation of hydrodissection in microwave ablation of liver tumours in difficult locations

Objective

To investigate the safety and mid-term outcomes of hydrodissection-assisted microwave ablation (MWA) of hepatocellular carcinoma (HCC) in various difficult locations.

Methods

A total of 131 HCC patients who underwent ultrasound-guided MWA from March 2017 to March 2019 were included. Following ultrasound examination, patients with tumors at difficult locations were treated with hydrodissection-assisted MWA (hydrodissection group), while those with tumors at conventional locations received MWA (control group). Both groups were compared concerning baseline characteristics, ablation parameters, complete ablation rates, and complication rates. Kaplan-Meier curves analyzed local tumor progression and overall survival, with stratified analysis for different difficult locations (adjacent to gastrointestinal tract, diaphragm, and subcapsular tumors). Additionally, Cox regression analyses were conducted to assess the impact of different difficult locations on these outcomes.

Results

Complete ablation rates were similar between the hydrodissection and control groups (91.4% vs. 95.2%, P>0.05). Postoperative complications occurred in three patients, including liver abscess and biliary injury. No significant differences in major or minor complication rates were found between the groups (P>0.05). Local tumor progression was detected in 11 patients (8.4%) at the end of the follow-up period. Neither cumulative local tumor progression rate (P=0.757) nor overall survival rate (P=0.468) differed significantly between the groups. Stratified analysis showed no effect of tumor location difficulty on cumulative local tumor progression or overall survival. Tumor number and size served as independent predictors for overall survival, while minimal ablation margin ≤ 5mm independently predicted local tumor progression. In contrast, the tumor location was not statistically significant. Sensitivity analyses corroborated the robustness of the models.

Conclusion

Hydrodissection-assisted MWA for HCC in various difficult locations demonstrated safe and effective, with complete ablation and mid-term outcomes comparable to those for tumors in conventional locations.

Feasibility of laparoscopic microwave ablation of caudate tumors: a case series

Microwave ablation of liver tumors allows preservation of liver parenchyma with good oncologic outcomes. However, ablation of tumors in the caudate lobe is particularly challenging. Adjacent critical anatomy, particularly the biliary hilum, has led to caudate location being considered a relative contraindication to ablation. To date, no series have described laparoscopic microwave ablation of caudate tumors of the liver. We describe our early experience with laparoscopic microwave ablation of caudate tumors. In this retrospective review of a prospectively maintained single-institution database, six patients with six primary or secondary caudate tumors underwent laparoscopic microwave ablation with no complications. At a median follow-up of 10.5 months, five out of six patients are free of caudate recurrence. Laparoscopic microwave ablation of caudate tumors is feasible. Long-term follow-up is needed to determine if local recurrence risk is higher than in other anatomical segments.

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.

Artificial ascites using the guidewire technique during microwave ablation in the liver dome: technique and analysis of fluid repartition

PURPOSE

To describe the guidewire technique to perform hydrodistension and create artificial ascites during liver microwave ablation (MWA) of tumors located in the hepatic dome and evaluate the effectiveness of repartition of peritoneal fluid along segments VII and VIII with this technique.

MATERIALS AND METHODS

A retrospective review of all 18 consecutive patients who benefited from MWA combined with hydrodistension causing artificial ascites performed with the guidewire technique was conducted. The technique involves inserting a 20G spinal needle in the liver parenchyma and catheterizing the peritoneum with a 0.018 nitinol guidewire while retrieving the needle from the liver. Technical success was defined by the successful insertion of a sheath over the wire in the peritoneal cavity and identification of peritoneal fluid on CT images, with repartition of ascites around segments VII and VIII.

RESULTS

Target tumors were located in segments VII and VIII and had a mean size of 27.7 mm with a mean distance from the diaphragm of 1.7 mm. Technical success of artificial ascites was 14/18 (78%). In the four cases where artificial ascites failed, patients had undergone previous liver surgery. In the 14 cases for which artificial ascites were successful, complete separation of the diaphragm from the ablation zone was noted in 9/14 cases and partial separation in 5/14 cases.

CONCLUSION

Hydrodistension with the guidewire technique is effective and safe to accomplish artificial ascites. The extent of repartition of peritoneal fluid is variable, especially in the peritoneal recess in contact with the bare area where diffusion of fluid was variable.