title: Effect of nerve graft porosity on the refractory period of regenerating nerve fibers.
abstract: OBJECTIVE
  In the present study the authors consider the influence of the porosity of synthetic nerve grafts on peripheral nerve regeneration.
  
  
  METHODS
  Microporous (1-13 microm) and nonporous nerve grafts made of a copolymer of trimethylene carbonate and epsilon-caprolactone were tested in an animal model. Twelve weeks after surgery, nerve and muscle morphological and electrophysiological results of regenerated nerves that had grown through the synthetic nerve grafts were compared with autografted and untreated (control) sciatic nerves. Based on the observed changes in the number and diameter of the nerve fibers, the predicted values of the electrophysiological parameters were calculated.
  
  
  RESULTS
  The values of the morphometric parameters of the peroneal nerves and the gastrocnemius and anterior tibial muscles were similar if not equal in the rats receiving synthetic nerve grafts. The refractory periods, however, were shorter in porous compared with nonporous grafted nerves, and thus were closer to control values.
  
  
  CONCLUSIONS
  A shorter refractory period enables the axon to follow the firing frequency of the neuron more effectively and allows a more adequate target organ stimulation. Therefore, porous are preferred over nonporous nerve grafts.
authors.affiliation: Department of Neurosurgery, Leiden University Medical Centre, Leiden, The Netherlands. cvleggeert@lumc.nl
authors.forename: Carmen L A M
authors.initials: CL
authors.lastname: Vleggeert-Lankamp
authors.forename: Jasper
authors.initials: J
authors.lastname: Wolfs
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Pêgo
authors.forename: Rutgeris
authors.initials: R
authors.lastname: van den Berg
authors.forename: Hans
authors.initials: H
authors.lastname: Feirabend
authors.forename: Egbert
authors.initials: E
authors.lastname: Lakke
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D005260:Female; D008855:Microscopy, Electron, Scanning; D008959:Models, Neurological; D018482:Muscle, Skeletal / Q000294:innervation; D009412:Nerve Fibers / Q000502:physiology; D009416:Nerve Regeneration / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology / Q000601:surgery; D019736:Prostheses and Implants / Q000648:ultrastructure; D019919:Prosthesis Implantation; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000502:physiology* / Q000601:surgery*