For the first time, a study has shown visual evidence of biofilm during “aseptic” revision spine surgery. The article, “High Prevalence of Biofilms on Retrieved Implants from Aseptic Pseudarthrosis Cases,” was published by the Japanese Society for Spine Surgery and Related Research. Aakash Agarwal, Ph.D., and colleagues Megan Mooney, Ashish G. Agarwal, Daksh Jayaswal, Gayane Saakyan, Vijay Goel, Jeffrey C. Wang, Neel Anand, Steve Garfin, Vithal Shendge and Hossein Elgafy authored the study.
Researchers Find Visual Evidence of Biofilm
What inspired the researchers to conduct this study?
Aakash Agarwal, Ph.D., who is Director of Research at Spinal Balance AND a leading researcher in the Departments of Bioengineering and Orthopaedic Surgery at the University of Toledo, had observed that recent research has shown cultures of bacteria and high correlation between presence of bacteria during supposedly “aseptic revision surgery.” Two such studies, published in European Spine Journal and Journal of Neurosurgery, also showed strong evidence of correlation between bacteria presence and screw loosening.
Agarwal and his colleagues decided to follow up on this research, as well as their own previous research, which indicated that orthopedic surgeons are impregnating bacterial biodose in patients through use of repeatedly reprocessing and intraoperatively exposing implants during surgery. The subsequent research results showed, for the very first time, documented evidence of surreptitious biofilm in patients requiring “aseptic” revision surgery (with no clinical signs of infection).
Agarwal said, “For the past couple of years, numerous leading researchers around the world have shown evidence regarding higher prevalence of positive microbial cultures in revision spine surgeries… Many of these researchers (especially the recent ones) also reported higher correlation of these positive microbial cultures with pseudarthrosis, or screw loosening. These past authors have used the terms: occult infection, chronic implant infection etc. to describe this scientific observation.”
Catalysts for the Research
This caused Agarwal and his colleagues to wonder why this was happening and what the root cause of such infection might be. He stated, “the answer to which I have pointed out in my previous collaborative work, [is] that most implants are undergoing contamination both preoperatively and intraoperatively. The solution to this is two-step asepsis. Unless we adhere to two-step asepsis and avoid these known modes of contamination during spine surgery, there is no scientific way to identify additional sources of risk factors that may be associated with it.”
A second concern of the researchers was the serious risks of such secondary infections.
Agarwal explained that much previous research has already associated biofilm infection after revision surgery with late onset infection and/or pseudoarthrosis. The current body of research on this topic, according to Agarwal, is “excellent, and the only reason the scientific community have not completely digested the enormous body of work is because they worry that it is easy to contaminate retrieved study samples and have false positives.”
“However, if you can demonstrate presence of biofilm on implants from failed spine surgery via visual means, it strongly supports the studies previously conducted by all these researchers showing positive culture.”
