Affiliations: Division of Plastic and Reconstructive Surgery,
Department of Surgery, Washington University School of Medicine, Saint Louis,
MO, USA | Department of Otolaryngology, Head & Neck Surgery,
Washington University School of Medicine, Saint Louis, MO, USA
Note: [] Corresponding author: Susan E. Mackinnon, M.D., Division of
Plastic and Reconstructive Surgery, Washington University School of Medicine,
660 South Euclid Avenue, Room 5401, Box 8238, Saint Louis, Missouri 63110, USA.
E-mail: mackinnons@msnotes.wust.edu
Abstract: Purpose: This study investigated nerve regeneration following nerve
repair with longitudinally oriented sutures, with emphasis on timing. Prior
work in rodents has shown that suture scaffolds are comparable to nerve
grafting when assessments are made at late time points. However, rodents have
exceptional regenerative capacity, making it difficult to detect key
differences at late time points. This study therefore investigated regeneration
across suture scaffolds both at early (4 week) and late (12 week) endpoints.
Methods: Rodents were randomized to nerve gap, transection and
repair, nerve grafting, and suture scaffold groups. Nerve regeneration was
evaluated at 4 and 12 weeks. Histomorphometry parameters were evaluated using
binary image analysis of toluidine blue-stained nerve cross sections. Results: Compared to nerve grafts, suture scaffolds were
associated with significantly decreased neural density (4208 ± 3546 vs.
193 ± 416, fibers/mm^2, p<0.05) and fiber width
(1.92 ± 1.21 vs. 0.75± 1.16, μm, p<0.05). At 12 weeks,
differences between groups were no longer detectable. Conclusion: When evaluated at optimal time points for rodents,
suture scaffolds fail to support regeneration comparable to the existing gold
standard of nerve grafting. This finding raises significant concerns regarding
the clinical application of suture scaffolds.
