End-to-side coaptation--controversial research issue or important tool in human patients.

End-to-side coaptation is still a controversial procedure. Many authors reported surprisingly good results; others showed mediocre results only. There are also reports of complete failures. Apparently all authors are right. According to our experience the results depend on the level of end-to-side coaptation and on the nerve fiber composition. End-to-side coaptation between mixed nerves do have very poor expectations. The chances are much better if e.g. a small denervated pure motor nerve is coapted to a functioning small pure motor nerve. The same procedure may produce opposite results according to the circumstances. In our experience end-to-side coaptation is a reliable procedure of great use in selected cases. Main field of application are thin nerves with a well defined function and synergistic terminal motor branches.