Long-Term Functional and Histological Outcomes Following Sutureless Peripheral Nerve Repair Using Nerve Tape in Pigs

Imagine your body is a bustling city, and your nerves are the high-speed fiber-optic cables that carry messages from your brain to your muscles, telling them when to move, feel, or react. Sometimes, a severe accident can snap one of these cables. When that happens, surgeons have to play the role of master electricians, trying to reconnect the two broken ends so the signal can flow again. For decades, the standard way to do this has been "microsurgery," where a surgeon uses a microscope and tiny needles to stitch the nerve ends together, thread by thread. It's a bit like trying to sew two frayed ropes back together by hand while wearing oven mitts: it takes a long time, requires incredible precision, and if the alignment isn't perfect, the message might get scrambled or lost. But what if there was a faster, easier way to tape those cables back together without all the stitching? This is the big question scientists are asking: can a new, glue-like device called "Nerve Tape" do the job just as well, or maybe even better, than the old-school sewing method?

This study decided to find out by testing this new Nerve Tape on Yucatan minipigs, which are great stand-ins for humans because their nerves are similar in size and structure. The researchers cut the common peroneal nerve in the pigs' legs and then repaired it using one of two methods: either the traditional, time-consuming micro-suturing (stitching) or the new, sutureless Nerve Tape. They then waited a long time—12 months—to see how well the nerves healed and how well the muscles they control started working again. They looked at two specific muscles: the tibialis anterior (which helps lift the foot) and the extensor digitorum brevis (a smaller muscle further down the foot).

The results were quite interesting. When it came to the tibialis anterior muscle, both the stitching group and the Nerve Tape group did about the same; the nerves healed, and the muscles recovered similarly. However, the Nerve Tape really shined when it came to the more distant muscle, the extensor digitorum brevis. In this area, the Nerve Tape group showed much stronger recovery. The electrical signals (called compound muscle action potential) were about 1.8 times stronger in the tape group compared to the stitching group. In terms of percentage recovery, the Nerve Tape group reached 74.3%, while the stitching group only reached 46.0%. The electrical signals traveling through the nerve itself were also stronger with the tape, though the speed at which those signals traveled was the same for both groups.

When the scientists looked at the nerves under a microscope, they found that the internal structure of the nerve fibers looked healthy and well-organized in both groups. There was no significant difference in the number of nerve fibers, their size, or how thick their protective coating was. This suggests that the Nerve Tape didn't damage the nerve's delicate architecture. The study also included a real-life example where a human patient was treated with the tape and showed progressive recovery, hinting that this method works outside the lab too. Ultimately, the paper suggests that while both methods work, the Nerve Tape might offer a faster, easier way to repair nerves that leads to better recovery in the muscles furthest away from the injury, without sacrificing the structural health of the nerve.