Spinal care: Team approach at the bedside and in the lab

Sept. 24, 2019

As a fully integrated center, Mayo Clinic follows a multidisciplinary team approach for complex spinal oncology surgery. Orthopedic surgeons routinely work with neurosurgeons, ENT surgeons and other specialists as needed to provide optimal surgical outcomes.

"We have a team with multiple people, deep at every position," says Michael J. Yaszemski, M.D., Ph.D., a spinal surgeon at Mayo Clinic in Rochester, Minnesota. "It's like an orchestra. When it's your turn, you do what you need to do. When your part is done, you step back and someone else leads. Everyone here just tucks the ego away and does what's best for the patient."

The team approach is followed throughout the process of diagnosis and treatment. "When you come to Mayo Clinic for a sarcoma evaluation, for example, you see the surgeons, a medical oncologist and a pediatric oncologist if the patient is a child," Dr. Yaszemski says. The team also includes radiation oncologists, pathologists who specialize in bone cancer, musculoskeletal radiologists and chemotherapy specialists.

Dr. Yaszemski cites the case of a patient with a highly challenging chondrosarcoma in the cervical spinal canal. The patient's initial evaluations involved two orthopedic surgeons, a head and neck surgeon, and a neurosurgeon.

"Together we made a plan," Dr. Yaszemski says. "We decided that our head and neck colleague should start the procedure, to provide maximum precision and safety for the patient. Orthopedic surgeons planned the osteotomy — we knew we wanted to get through the bone at a specific location. We practiced the tumor removal beforehand. It took just three minutes during the procedure, even though nerves VI and VII were stuck to the tumor. Our spinal neurosurgery colleague separated the sixth and seventh cervical nerves from the tumor, and then we asked our peripheral nerve neurosurgeon for an evaluation to reconstruct those resected nerves."

The peripheral nerve neurosurgeon recommended waiting three months before attempting nerve transfer to restore function to the patient's right arm. That surgery was successful. "Six years out, the patient has normal function. I can't break her extension muscle strength. I can't break her wrist flexion muscle strength. She's doing very well," Dr. Yaszemski says.

Regenerating bone and nerves

Mayo Clinic's research laboratories follow a similar team approach. Under Dr. Yaszemski's direction, the work of the Tissue Engineering and Biomaterials Laboratory ranges from basic science discoveries to the development of polymeric biomaterials for regenerative medicine treatments. "Everything we do in this lab has as its starting point an unmet clinical need," Dr. Yaszemski says.

The long-term research goal is to fundamentally change treatment through the use of biodegradable polymers that act as scaffolds for the regeneration of bones and nerves. One current investigation involves the development of an electrically charged bone biomaterial that can act as both a bone scaffold and a protein delivery vehicle. In a study to be published in Tissue Engineering Part A, researchers in the lab demonstrated that a negative charge significantly enhances bone morphogenic protein-induced bone formation compared with a neutral or a positive charge in oligo [(polyethylene glycol) fumarate] (OPF) hydrogels.

"The use of polymer scaffolds in patients with chronic nonunion of bone fractures could have a major impact on healing and reduce the need for metal instrumentation," Dr. Yaszemski says.

The biomaterials lab's work on nerve scaffolds, done in conjunction with Mayo's Regenerative Neurobiology Laboratory, holds similar potential to revolutionize the treatment of patients with spinal injuries. In a study published in the January 2018 issue of the Journal of Tissue Engineering and Regenerative Medicine, Mayo Clinic researchers demonstrated that OPF scaffolds delivering Schwann cells genetically modified to secrete high concentrations of glial cell-derived neurotrophic factor can promote regional axonal regeneration, remyelination and functional improvement in lab animals after spinal cord transection.

To facilitate translation of laboratory work into clinical trials, Mayo Clinic has a biomaterials and biomolecules manufacturing facility that follows current good manufacturing practices (CGMP). The facility is directed by Dr. Yaszemski and Anthony J. Windebank, M.D., a neurologist at Mayo Clinic in Rochester, Minnesota. The Food and Drug Administration recently granted an investigational device exemption for Mayo Clinic's nerve regeneration scaffold to be fabricated in the Mayo CGMP facility.

"This research moves forward because the different labs bring different perspectives," Dr. Yaszemski says. "At Mayo, that teamwork just comes naturally to us."

For more information

Tissue Engineering and Biomaterials Laboratory. Mayo Clinic.

Olthof MGL, et al. Effect of biomaterial electrical charge on bone morphogenetic protein-2-induced in vivo bone formation. Tissue Engineering Part A. 2019;25:1037.

Chen BK, et al. GDNF Schwann cells in hydrogel scaffolds promote regional axon regeneration, remyelination and functional improvement after spinal cord transection in rats. Journal of Tissue Engineering and Regenerative Medicine. 2018;12:e398.