BACKGROUND: The purpose of this study was to investigate the recovery of a common target motor function after different single and combined motor nerve transfers in rat brachial plexus model. METHODS: The musculocutaneous nerve and biceps muscle were chosen as the target for neurotization. The phrenic, pectoral, and suprascapular nerves were selected as the neurotizers. Forty-two Sprague-Dawley rats were randomly assigned to seven groups (six rats in each group): single-neurotizer transfer (three groups), double-neurotizer transfer (three groups), and triple-neurotizer transfer (one group). The contralateral intact forelimb was used as a control. Functional outcomes were measured by grooming test, electrophysiological study, muscle contraction strength, muscle weight, and axon counts. RESULTS: At 12 weeks, 40 operative rats were studied (two had died). In the single-neurotizer transfer, all three transfers showed no significant difference in motor recovery of the biceps. In the double-neurotizer transfer groups, the worst results were seen in group 6 (combined pectoral and suprascapular nerve transfer) despite increasing axon counts. CONCLUSIONS: This study may potentially suggest: (1) single-neurotizer transfer will not have synergistic or antagonistic effects; (2) two neurotizers with functional antagonism will significantly downgrade motor recovery of the neurotized muscle despite increasing axon counts; (3) multiple motor neurotizer transfers may not always provide a better outcome, although increasing axons may outweigh antagonistic effects; and (4) phrenic nerve transfer alone did not upgrade the functional outcome despite its automatic discharge. Any nerve transfer combined with phrenic nerve transfer, however, showed improved functional results.
BACKGROUND: The purpose of this study was to investigate the recovery of a common target motor function after different single and combined motor nerve transfers in rat brachial plexus model. METHODS: The musculocutaneous nerve and biceps muscle were chosen as the target for neurotization. The phrenic, pectoral, and suprascapular nerves were selected as the neurotizers. Forty-two Sprague-Dawley rats were randomly assigned to seven groups (six rats in each group): single-neurotizer transfer (three groups), double-neurotizer transfer (three groups), and triple-neurotizer transfer (one group). The contralateral intact forelimb was used as a control. Functional outcomes were measured by grooming test, electrophysiological study, muscle contraction strength, muscle weight, and axon counts. RESULTS: At 12 weeks, 40 operative rats were studied (two had died). In the single-neurotizer transfer, all three transfers showed no significant difference in motor recovery of the biceps. In the double-neurotizer transfer groups, the worst results were seen in group 6 (combined pectoral and suprascapular nerve transfer) despite increasing axon counts. CONCLUSIONS: This study may potentially suggest: (1) single-neurotizer transfer will not have synergistic or antagonistic effects; (2) two neurotizers with functional antagonism will significantly downgrade motor recovery of the neurotized muscle despite increasing axon counts; (3) multiple motor neurotizer transfers may not always provide a better outcome, although increasing axons may outweigh antagonistic effects; and (4) phrenic nerve transfer alone did not upgrade the functional outcome despite its automatic discharge. Any nerve transfer combined with phrenic nerve transfer, however, showed improved functional results.
Authors: K D Bergmeister; M Aman; O Riedl; K Manzano-Szalai; M E Sporer; S Salminger; O C Aszmann Journal: Eur Surg Date: 2016-02-01 Impact factor: 0.953
Authors: Aleksandra M McGrath; Johnny Chuieng-Yi Lu; Tommy Naj-Jen Chang; Frank Fang; David Chwei-Chin Chuang Journal: Plast Reconstr Surg Glob Open Date: 2016-12-13