Spongy polymer grows to fill gaps in the spine after surgery
Removing spinal tumors can be problematic, with the current options for bridging the gap left bythe procedure being either very expensive, or extremely invasive. Newresearch could provide a better solution, with the potential touse an expanding polymer implant to fill the gaps after surgery.
When a metastatic spinal tumor isremoved, significant amounts of bone and entire intervertebral discsare often removed. The resulting space has to be filled in order toprotect the spinal cord and maintain the strength of the spine, butcurrent techniques for doing so are far from ideal.
Surgeons are generally faced with twooptions. They can either open the patient's chest cavity to insertmetal cages or bone grafts, or make an incision into the posterior orback, using small, expandable titanium rods to bridge the gap in thespine. The first option is extremely invasive, while the second isexpensive, due to the high cost of the materials involved.
The new research might provide doctorswith a third, more palatable option. The graft, developed byscientists at the Mayo Clinic in Minnesota, is put in place in thesame way that titanium rods are inserted in currently treatments – through asmall incision on the patient's back or posterior – but makes use of muchcheaper materials.
The new implant is made from a biocompatible,hydrophilic polymer, which is crosslinked to create a hollow cage.Filled with stabilizing materials and therapeutic drugs, the graft canbe inserted into the body, expanding as it takes on fluid, andultimately filling the void left by the tumor-removal surgery.
The team spent a great deal of timeperfecting the expansion properties of the device, making sure thatit grows fast enough so as not to require unnecessarily lengthyoperations, but slow enough to give surgeons enough time to properlyplace the graft. The information was gathered by observing thepolymer grafts under conditions that mimic those found inthe body, while altering the diameter of the scaffold mold, as wellas the molecular weight and charge of the material.
The scientists plan to continue their research on the new treatment, working first with cadavers toaccurately simulate the implant at work. The team is aiming toconduct a clinical trial with the next few years.
The research is being presented at ameeting of the American Chemical Society (ACS) this week. For more information, you can take a look at the video below.