Oregon State University research reveals solution to common surgical problem of nerve damage
PORTLAND, Ore. — A research collaboration including scientists from Oregon State University has developed new technology to help surgeons know where a patient’s nerves are, reducing the risk of nerve damage.
The technology is based on hydrogels, three-dimensional networks of polymers that absorb and retain large amounts of water, and targets a widespread and persistent surgical complication.
According to Adam Alani of OSU, depending on the procedure, a patient can face a double-digit percentage risk of suffering nerve damage.
For example, he notes, people who need their thyroid gland removed are looking at a 15% chance of voice changes resulting from damage to their recurrent laryngeal nerves.
Apply these odds to the 12% of the US population who are susceptible to developing thyroid disease, for which thyroidectomy is a common treatment, and the numbers for this type of surgery alone are staggering.
“Nerve-sparing techniques have been around for decades, but identifying and nerve-sparing remains a great challenge, with success rates strongly correlated to an individual surgeon’s skill and experience,” Alani said. , a researcher at the OSU College of Pharmacy. “Intraoperative nerve damage affects all surgical specialties and is a significant problem even for surgeries that are performed all the time such as prostatectomies, hysterectomies, hernia repairs and thyroidectomies.”
Alani, an adjunct faculty member at Oregon Health & Science University, worked with OHSU colleague Summer Gibbs on the study, which was funded by the National Institutes of Health. The results have been published in Biomaterials.
The research is an important step toward improving a nerve-sparing technique called fluorescence-guided surgery, or FGS. Specific tissues, in this case nerves, can be better detected if they fluoresce, that is, they emit light after absorbing light or another type of electromagnetic radiation.
For tissues to do this, they must be treated with a fluorophore, microscopic molecules that absorb and emit light of specific wavelengths.
Working with scientists from OHSU and Intuitive Surgical, Alani’s lab developed an effective fluorophore hydrogel based on compounds called pluronics. Also known as poloxamers, Pluronics are polymers synthesized by the condensation of ethylene oxide and propylene oxide.
“Hydrogels have been used successfully to provide contrast agents in imaging technologies such as MRI and CT scans,” Alani said. “And Pluronics are already used as a drug delivery agent in Food and Drug Administration-approved products. The physical characteristics of our Pluronics-based formulation allow a nerve-specific staining solution to be applied with relative ease as a liquid, then it stays put after almost instantly forming a gel.
Successful testing in two animal models — mouse and pig — suggests the new technology is “a clinically viable method for fluorescence-guided nerve sparing during thyroidectomy as well as other procedures,” Alani said.
And because Pluronics already has FDA approval, the technology is eligible for expedited regulation under the agency’s guidelines for “investigative new drugs.” The guidelines allow for exploratory approaches to early phase 1 clinical trials involving safe microdoses of potential drug candidates, allowing researchers to move forward faster than usual.
“Direct administration of a contrast agent to the treatment area is an attractive alternative to systemic administration of fluorescent probes,” Alani said. “Selective tissue labeling only in the surgical field requires a significantly lower dose than systemic administration.”
Vidhi Shaw, Adel Al-Fatease and Syed Zaki Husain Rizvi from OSU’s College of Pharmacy also contributed to the study.
Alexander Antaris and Jonathan Sorger represented Intuitive Surgical, developer of the widely used da Vinci robotic surgical system with which the new technology is compatible, Alani said.