Vessel-X (Spirit Spine) is a device used to undertake “vesselplasty” procedures, designed to restore vertebral body height following a vertebral compression fracture using a non-stretchable PET (polyethylene terephthalate) container. The container is inflated using low viscosity, biocompatible cement (Osteo-G, Spirit Spine), which then percolates through the mesh lining into the void. Vessel-X lifts up the endplates and then fills the void with biocompatible material, while maintaining the height correction.
New clinical trials for Vessel-X began in France in May, with the first follow-up results expected at the end of this year. Spinal News International spoke to Bambang A Darwano, Pluit Hospital and Gading Pluit Hospital, Indonesia, and Jean-Denis Laredo, Hôpital Lariboisière and Université Paris-Diderot, France, about their experiences using the platform, and where they believe it sits in the range of techniques used to treat vertebral compression fractures.
Why would you use Vessel-X instead of vertebroplasty or kyphoplasty?
Laredo: As soon as you have a large cortical break (sometimes you have no more cortical bone), especially when the posterior vertebral body cortex is involved, there is a risk of leakage when using vertebroplasty or kyphoplasty.
In such situations, using Vessel-X is helpful since the container retains cement when you start the injection, at which time the cement is fluid. Once the container is filled, the pressure starts to build after several minutes and the cement starts to slowly filtrate through the container’s pores. The cement is harder at that time, meaning there is less risk of leakage.
The most important point is that you have less pressure overall, because the Vessel-X retains it, decreasing the risk of cement leakage compared to using plain vertebroplasty. Compared with balloon kyphoplasty, in which you can lose part of the height you just regained when you deflate and retrieve the balloon prior to cement injection, with vesselplasty there is no loss of vertebral body height.
Bambang: With vertebroplasty, when you inject cement into the fractured vertebra, the pressure forces the cement to the fracture site and can cause leakage. Using high viscosity cement such as in vesselplasty is safer compared with the low viscosity cement. Also, vertebroplasty technique is not designed to restore the vertebral body height.
Kyphoplasty is designed to restore the vertebral body height by creating a void using a balloon inflated by an injection of water. The balloon is then removed and the void it created is filled with cement. When injecting the cement, it will once again go to the weakest area—the fracture site—and lead to a leakage. Furthermore, in-between balloon removal and cement injection, there will be some collapse of the void created.
For what indications would you use this procedure?
Laredo: There is one indication that I am certain about the advantage of Vessel-X, and that is in bone metastases, where our main problem is leakage of cement. I used it recently to carry out a procedure at the first cervical vertebra, which was mostly destroyed by multiple myeloma. The procedure was very risky, but I was able to reconstruct the C1 lateral mass using Vessel-X without any cement leakage. Another indication may be osteoporotic fractures with an intravertebral cleft (osteonecrosis) where there is no tendency to heal, a condition sometimes called Kummel’s Disease. In such cases, it is usually possible to regain much height of the vertebral body by using vesselplasty.
Why do you think Osteo-G is a better cement to use than plain PMMA?
Bambang: If we use PMMA inside the osteoporotic vertebra, the stiffness of PMMA remains constant throughout the patient’s life, but the surrounding bone density is constantly degrading because of ageing and sometimes also due to osteoporosis. The result is a stiffness mismatch at the interface, which can lead to a loosening of PMMA or fracture of the osteoporosis bone. Osteo-G is bioactive cement, contains only 8% PMMA as a scaffold, and is mainly SrHA (strontium hydroxyapatite) and calcium sulphate. The Osteo-G induces a new bone formation at the interface and avoids the problems associated with PMMA. A CT scan at six months after the procedure shows the new bone at the interface compare to CT just after injection. An animal study conducted at Hong Kong University shows the same result at the interface.
Do physicians need extra training to carry out the procedure?
Laredo: You do not need extra training if you are used to performing balloon kyphoplasties. You just have to have the seller with you when you are doing the first procedure, because any different type of device has specific technical needs. It takes around 15–20 minutes longer than vertebroplasty or kyphoplasty.
What are the risks of using Vessel-X?
Laredo: So far I have not encountered any problems.
Bambang: I have completed more than 1,000 vesselplasty procedures using Vessel-X since 2004. The cost is equal to using balloon kyphoplasty and up to this point I have experienced no negatives effects when using Vessel-X—if it is done properly. Of course we do still have to face the possibility of leakage.
Do you think this will become a more popular procedure?
Laredo: I have been using Vessel-X for less than one year and I only know of one other neuroradiologist in Paris using it—it is not that well-known in France at the moment. We only recently received the authorisation to buy it officially. In the French system, to buy a new medical device, you have to prove that it provides a better service compared with other available treatments.
I believe it will become more popular if it continues to do well, which I think it will. The question is whether it is worth the price, and if it is bringing good results, which it has been, then the answer to that question is yes.
Bambang: Once other physicians understand the concept of vesselplasty and the necessary steps to carry out the procedure successfully, I believe that many doctors will begin using it. The procedure’s safety, the ability to prevent leakage and the benefits associated with using bioactive cement all make this an attractive option.