Illustration of liver tumor ablation using hydrodissection technique.

Hydrodissection: A Revolutionary Technique for Liver Tumor Treatment

Elliot Brynn in Health & Wellness July 2025 • 4 min read.

"Discover how a novel approach is physically separating liver tumors from critical blood vessels, improving ablation outcomes, and reducing risks."

Liver cancer treatments have evolved significantly, and percutaneous imaging-guided ablation has become a common approach for treating hepatic malignancies. Ablation involves using heat to destroy tumor cells. Unfortunately, tumors near major blood vessels pose a challenge, because the blood flow dissipates the heat, reducing the effectiveness of the ablation. This phenomenon, known as the "heat-sink" effect, can lead to incomplete treatment and higher recurrence rates.

To combat the heat-sink effect, researchers have explored various strategies, including endovascular occlusion of the inferior vena cava (IVC) and alternative ablation techniques like microwave ablation (MWA) and irreversible electroporation (IRE). Hydrodissection, which involves injecting fluid between the tumor and adjacent structures, is now creating excitement.

A recent study highlights the use of retrohepatic hydrodissection to physically separate liver tumors from the IVC and hepatic veins. This innovative technique aims to minimize the heat-sink effect and improve ablation outcomes. Here’s how it works and what the initial results suggest.

How Does Retrohepatic Hydrodissection Work?

Illustration of liver tumor ablation using hydrodissection technique.

Retrohepatic hydrodissection involves injecting fluid into the retrohepatic space to create a physical barrier between the liver tumor and the inferior vena cava (IVC) and hepatic veins (HV). This separation is intended to reduce the heat-sink effect during thermal ablation, allowing for more effective tumor treatment and reducing the risk of vascular injury.

Between December 2017 and April 2018, researchers conducted a study involving five female patients with liver metastases located close to the IVC. The procedure involved several key steps:

Needle Placement: Two to three 22G spinal needles were inserted percutaneously under CT guidance to access the retrohepatic space.
Fluid Injection: A mixture of 5% iodinated contrast and 0.9% saline solution was injected to dissect the space between the tumor and the IVC/HV. The mean volume of fluid used was 410 ml.
Separation: The fluid injection physically separated the tumor from the IVC and the ostia of the right and middle hepatic veins. The average separation achieved was 9 mm.
Ablation: After hydrodissection, microwave ablation (MWA) was performed to destroy the tumor cells.

Following the procedure, patients were monitored for complications and underwent follow-up imaging to assess the effectiveness of the treatment. Researchers collected data on the distance between the IVC and the tumor, the length and thickness of the dissection, and any complications encountered.

What are the Potential Benefits and Future Directions?

Retrohepatic hydrodissection is a feasible technique to separate a tumour from the IVC and/or ostia of the HV, potentially limiting the heat-sink effect and reducing the risk of thrombosis. All lesions but one were completely ablated after one session at 3-month follow-up. The patient with residual tumour was successfully retreated. This advancement is an excellent step towards more effective and safer ablation of liver tumors located near critical blood vessels. More extensive studies are warranted to assess the efficacy on a long-term basis.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1007/s00270-018-2105-y, Alternate LINK

Title: Hydrodissection Of The Retrohepatic Space: A Technique To Physically Separate A Liver Tumour From The Inferior Vena Cava And The Ostia Of The Hepatic Veins

Subject: Cardiology and Cardiovascular Medicine

Journal: CardioVascular and Interventional Radiology

Publisher: Springer Science and Business Media LLC

Authors: Julien Garnon, Guillaume Koch, Jean Caudrelier, Emanuele Boatta, Pramod Rao, Maud Nouri-Neuville, Nitin Ramamurthy, Roberto Luigi Cazzato, Afshin Gangi

Published: 2018-11-01

Everything You Need To Know

What is retrohepatic hydrodissection and how does it improve liver tumor ablation?

Retrohepatic hydrodissection is an advanced medical technique where fluid is injected into the retrohepatic space to create a physical barrier between the liver tumor and the inferior vena cava (IVC) and hepatic veins (HV). This separation reduces the "heat-sink" effect, which occurs when blood flow dissipates heat during ablation, making the treatment less effective. By physically separating the tumor, retrohepatic hydrodissection allows for more effective tumor treatment and minimizes the risk of vascular injury, leading to improved outcomes in liver tumor ablation.

How does the "heat-sink" effect impact liver tumor ablation, and why is hydrodissection used to address it?

The "heat-sink" effect occurs during liver tumor ablation when tumors are located near major blood vessels such as the inferior vena cava (IVC) and hepatic veins (HV). The blood flowing through these vessels dissipates the heat generated during ablation, reducing the treatment's effectiveness. This can lead to incomplete tumor destruction and higher recurrence rates. Hydrodissection is used to combat this by creating a physical separation between the tumor and these blood vessels. This separation minimizes the heat-sink effect, ensuring that the ablation can effectively destroy the tumor cells.

What steps are involved in the retrohepatic hydrodissection procedure for liver tumor treatment?

The retrohepatic hydrodissection procedure involves several key steps. First, 2-3 spinal needles (22G) are percutaneously inserted into the retrohepatic space under CT guidance. Next, a mixture of 5% iodinated contrast and 0.9% saline solution is injected to dissect the space between the tumor and the inferior vena cava (IVC) and hepatic veins (HV). This fluid injection physically separates the tumor from these critical blood vessels. After hydrodissection, microwave ablation (MWA) is performed to destroy the tumor cells.

What were the outcomes and findings of the study using retrohepatic hydrodissection for liver tumor treatment?

The study, conducted between December 2017 and April 2018, involved five female patients with liver metastases located near the inferior vena cava (IVC). The results indicated that retrohepatic hydrodissection is a feasible technique to separate a tumor from the IVC and/or ostia of the hepatic veins (HV). The separation achieved was approximately 9 mm on average. Following the procedure, all lesions except one were completely ablated after one session at a 3-month follow-up. The patient with the residual tumor was successfully retreated, demonstrating the effectiveness and potential of this technique in improving ablation outcomes.

What are the potential benefits and future directions of retrohepatic hydrodissection in liver cancer treatment?

The potential benefits of retrohepatic hydrodissection include limiting the "heat-sink" effect and reducing the risk of thrombosis, leading to more effective and safer ablation of liver tumors, particularly those located near the inferior vena cava (IVC) and hepatic veins (HV). The initial study results were promising, showing complete ablation in most cases. Future directions involve more extensive studies to assess the technique's long-term efficacy and wider application in treating liver tumors. This innovative approach represents an excellent step towards improving patient outcomes in liver cancer treatment.