Targeted Muscle Reinnervation (TMR), a surgery technique originally developed for advanced prosthetics, also significantly reduces amputee limb pain, suggest researchers, according to results from a study published in Annals of Surgery.
Results from reportedly the first-ever published randomized clinical trial for the treatment of postamputation pain in major limb amputees suggest that TMR resulted in a significantly greater reduction in phantom limb pain and trended toward improved residual limb pain, compared to standard treatment for nerve and pain issues, according to a media release from Gregory Dumanian, MD.
In the study, Dumanian and others on his research team assigned 28 amputees with chronic pain to receive either standard treatment or TMR. The researchers then gathered information—including patient-rated pain scores, neuroma size, and functionality data—at 6 months, 12 months, and 18 months post-procedure. Patients in the study did not know whether they had received TMR or standard treatment for a full year after surgery.
Notably, three study participants who originally underwent standard treatment opted to have TMR performed after the 12-month mark. Eleven of the limbs treated with TMR had been amputated for 5 to 10 years or more.
“This study proves what we’ve seen anecdotally—that TMR is the first major advance in the way we treat residual and phantom limb pain since the onset of amputations thousands of years ago,” says Dumanian, chief of plastic surgery at Northwestern University’s Feinberg School of Medicine, lead researcher and study author, and originator of the TMR surgical procedure, in a media release.
“Respite from pain means freedom from narcotics, freedom to engage in physical activity, freedom to enjoy time with family and friends, freedom to pursue careers, and much more.”
According to the study, 72% of participants who underwent the procedure reported feeling mild or no phantom limb pain (PLP) after 18 months, compared with just 40% who underwent standard neuroma excision and muscle burying for chronic postamputation pain. Additionally, 67% of patients were free of or felt only mild residual limb pain following TMR, compared to 27% who received standard treatment.
“Our nervous system is like an electric grid, and severed nerves are like live wires that cause pain,” Dumanian notes.
TMR dissects the amputated nerve—the “live wire”—and surgically reroutes it to reinnervate a nearby functionless muscle, thereby “closing the circuit.” The reinnervation process allows the nerve to find end-receptors within the muscle, fooling the nerves into feeling “healed,” and more importantly, to feel less painful, per the release.
“Simply put, TMR gives the nerves somewhere to go and something to do, a strategy absent from all other neuroma treatments,” he says.
“Critically, we found that there’s really no shelf life on TMR,” Dumanian adds, also noting that there were no surgical complications to report. “It’s not too late to have the procedure if you’re more than a decade post-amputation, or if you’ve had nerve surgeries in the past, which is common among the amputee community.”
[Source(s): Gregory Dumanian, MD; PR Newswire]