ADVERTORIAL
A new device from Argon Medical is set to make liver biopsies easier, safer and quicker—and able to be completed by one operator without impacting efficacy.
The new TLAB® Transvenous Biopsy Instrument is the same dependable device that interventional radiologists rely on for liver biopsies, but now has FDA clearance for transfemoral transcaval access, and comes with an additional bending tool for navigating difficult anatomy.
Unlocking transfemoral access
According to Jacob Cynamon, MD, FSIR, director of the Division of Vascular and Interventional Radiology at Montefiore Einstein, utilizing transfemoral access for liver biopsies has fundamentally changed his practice pedagogy. It started when he was brought in to do a liver biopsy on a patient who had received right heart catheterization from the femoral vein. Rather than seeking out the traditional jugular access, Dr. Cynamon searched for veins available from the existing femoral route.
“There happened to be an accessory hepatic vein pointing down toward the femoral vein,” he said. “So, we got into that and did the liver biopsy. It was easy.”
After several more situations like this, Dr. Cynamon decided: his team would default to transfemoral transcaval access for liver biopsies.
Dr. Cynamon and Montefiore received IRB approval to make it standard procedure, applied for a patent for the technique and began collecting data and publishing results.
The benefits of transfemoral access
In 2020, Dr. Cynamon and his team published a retrospective review of 500 transvenous liver biopsies that compared the safety and efficacy of 286 transfemoral transcaval biopsies to 214 transjugular liver biopsies.1 This review found equivalent success rates between the two cases, while the transfemoral transcaval access procedures had fewer major complications, less fluoroscopic time and no significant hepatic injuries.
According to Kapil Wattamwar, MD, director of interventional radiology research at Montefiore Einstein, it’s not surprising that transfemoral access takes less time.
“When completing a traditional transjugular access biopsy, you must know what hepatic vein you’re in, as that determines how you angle your needle for the biopsy,” said Dr. Wattamwar. “For example, if you’re in the right hepatic vein, you would have to aim your needle anteriorly to grab a liver tissue. If you’re in the middle of the hepatic vein, which is an anterior structure, you should be aiming your needle posteriorly.”
The full process of selecting a hepatic vein while making sure the device and sheath are still in the hepatic vein, can take time, Dr. Wattamwar said. “Every time you get into the hepatic vein, you have to prove it by doing a lateral view or some other way of knowing whether you’re anterior or posterior.”
In comparison, the transfemoral approach allows IRs to perform the actual biopsy through the inferior vena cava without the need to select a particular hepatic vein.
“We demonstrated substantially less fluoroscopic time, almost by 40%,” Dr. Cynamon said. “And that includes getting the hepatic vein pressure.”
Measuring portal pressures and wedge pressures is a key component of most liver biopsies—but can also add time to a procedure. When utilizing a transfemoral approach, IRs can gather this measurement more easily.
“Whether you’re coming from above or below, you can still easily get into the hepatic veins to measure the pressures,” Dr. Wattamwar said. Once in the hepatic vein, an operator can effectively measure the pressure utilizing whatever method is preferred.
In addition to ease and time, Dr. Cynamon says the transfemoral approach also provides better cores during biopsy.
“There are fewer bends and turns when doing a transfemoral transcaval liver biopsy,” he said. “You’re not having to come in from the neck, turn the catheter into the hepatic vein and then turn down into the liver.” This approach also enables the biopsy to be done with one operator, rather than two, which is typically required for transjugular access.
“You need two operators for transjugular access because when you finally get your catheter into the hepatic vein, it can easily fall out because the patient is breathing and the liver is moving the catheter up and down,” Dr. Cynamon said. “So, you need someone to hold the sheath in the hepatic vein while you look at your samples.”
This can result in complications or injuries, Dr. Cynamon said, citing cases he’s heard of where an operator has made a hole in the hepatic vein in the liver while attempting to hold the sheath in place.
“With our procedure, and utilizing TLAB, we let go of the device,” Dr. Cynamon said. “It actually works to our benefit because we don’t have to worry about slipping out of the hepatic vein. We can allow the device to move and get another biopsy from a second location.”
With all these benefits combined, it seems obvious to Dr. Cynamon that transfemoral access should become a standard approach in the IR toolbox.
“Once you see it, and especially once you do it, everyone recognizes the simplicity and value of this approach,” he said.
The device that fits
Dr. Cynamon’s early data was published utilizing an off-label use of Argon’s existing liver biopsy kit, as there was no device available with an on-label indication for transfemoral access. However, after seeing the value of this approach, Argon partnered with Dr. Cynamon and Montefiore to create the new TLAB kit, a bidirectional device that is FDA cleared for both transjugular and transfemoral access.
The TLAB Transvenous kit includes Argon’s patented Flexcore® technology, which helps the needle conform to the curvature of the sheath. You also get the Tru-Track trocar tip and a fully exposed sample notch, which combine for a straight needle trajectory and maximum sample yield. In addition, the kit comes with swab sticks that allow the IR to remove samples without touching the needle.2
At Montefiore, the TLAB is the go-to device.
“It’s the kind of device that when there’s a case, the tech will pull it out without you needing to mention it to them because it’s almost synonymous with transvenous liver biopsies for us,” said Dr. Wattamwar.
Dr. Wattamwar said he appreciates that the device is rigid enough to maintain his position within the IVC, while providing a shaping flexibility that lets him modify the device for different cava sizes.
The new TLAB Transvenous kit comes with a bending tool, which allows IRs to adjust for difficult anatomy and makes it safer to navigate transfemoral access.
“The bending tool is crucial for transfemoral access because many IRs will change the angle of their metallic sheath, and the bending tool prevents kinking,” Dr. Cynamon said.
But even for those who don’t utilize transfemoral access, the bending tool is still a useful instrument to have on hand.
“In the event that you do need to do transfemoral access, you have an on-label device,” Dr. Cynamon said. “But in addition, you’ll have a bending tool for cases when you need to bend your device safely. It really is a no-brainer. If you’re doing liver biopsies, regardless of access, you should be using the new TLAB.”
References
- Peng R, et al. Transjugular versus transfemoral transcaval liver biopsy: A single-center experience in 500 cases. JVIR. 2020;31(9):1394-1400.
- TLAB. Argon Medical Devices. argonmedical.com/product/tlab-transvenous-liver-biopsy-system.
Disclaimer: This article is sponsored by an SIR Corporate Partner and does not necessarily reflect the views or policies of SIR. SIR assumes no liability, legal, financial or otherwise, for the accuracy of information in this article or the manner in which it is used. The statements made in the column are not intended to set a standard of care and should not be treated as medical advice nor as a substitute for independent, professional judgment.
