Tzou Chieh-Han, Lu Chuieng-Yi Johnny, Chang Tommy Nai-Jen, Chuang David Chwei-Chin
Division of Reconstructive Microsurgery, Department of Plastic Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria.
Microsurgery. 2017 Sep;37(6):647-654. doi: 10.1002/micr.30153. Epub 2017 Feb 16.
Distal nerve transfer has proven efficacy. The purpose of this study was to investigate if an injured nerve can be used as a donor nerve for transfer, and to determine the threshold of injury.
Rat's left ulnar-nerves in the axilla with different degrees of injury were selected as the donor nerves for transfer, and the musculocutaneous-nerves the target nerves for being re-innervated. Six rats each served as positive and negative controls: Group A, intact ulnar-nerve transfer; and Group E, the ulnar-nerve was cut but no transfer. Ten rats each were assigned to Group B to Group D with 25%, 50%, and 75% transected ulnar-nerve, respectively and all were transferred to the musculocutaneous-nerve. After a 12-week recovery period, outcomes were evaluated.
Biceps muscle weight measurements showed all experimental groups-D 0.28 ± 0.02 g/72%, C 0.28 ± 0.03 g/73%, B 0.29 ± 0.04 g/74%, and A 0.29 ± 0.04 g/80%-were lighter than group H 0.36 ± 0.04 g, which were all statistically significant (P < 0.001). Muscle tetanus contraction force measurements were the lowest in group D35 ± 8.6 g/69%. Groups C and B measured 41 ± 8.5 g/75% and 40 ± 2.2 g/77% and group A 41 ± 9.4 g/95%, respectively. Group H showed muscle contraction force of 52 ± 7.2 g, which was statistically significant when compared to experimental groups (P < 0.05-0.001). EMG measurements of the biceps muscles showed: group D was 3.6 ± 0.7 mV/69%, group C was 3.6 ± 0.6 mV/75%, and group B was 4.2 mV ± 0.7/81%. Group H was5.1 ± 0.7 mV and statistically significant different when compared with experimental groups (P < 0.05-0.001).Axon counts of healthy ulnar-nerve (Group H) were 1849 ± 362. Axon counts of the injured ulnar-nerve were in group B 1447 ± 579/78%, group C 1051 ± 367/57% and group D 567 ± 230/31%.
The donor nerve should be healthy in order to provide optimal result. A big nerve (e.g., ulnar nerve) but injured with at least 75% axon spared is still potentially effective for transfer. In contrast, a small nerve (e.g., intercostal nerve) once injured with 75%axon spared would be considered a suboptimal donor nerve.
远端神经移位已证实具有疗效。本研究的目的是调查受损神经是否可作为移位的供体神经，并确定损伤阈值。
选取大鼠左侧腋窝处不同程度损伤的尺神经作为移位的供体神经，肌皮神经作为重新支配的靶神经。每组6只大鼠分别作为阳性和阴性对照：A组，完整尺神经移位；E组，尺神经切断但未移位。每组10只大鼠，分别将25%、50%和75%横断的尺神经移位至肌皮神经，分为B组至D组。经过12周的恢复期后，对结果进行评估。
肱二头肌重量测量显示，所有实验组——D组0.28±0.02g/72%，C组0.28±0.03g/73%，B组0.29±0.04g/74%，A组0.29±0.04g/80%——均比H组0.36±0.04g轻，差异均具有统计学意义（P<0.001）。肌肉强直收缩力测量中，D组最低，为35±8.6g/69%。C组和B组分别为41±8.5g/75%和40±2.2g/77%，A组为41±9.4g/95%。H组肌肉收缩力为52±7.2g，与实验组相比差异具有统计学意义（P<0.05 - 0.001）。肱二头肌的肌电图测量显示：D组为3.6±0.7mV/69%，C组为3.6±0.6mV/75%，B组为4.2mV±0.7/81%。H组为5.1±0.7mV，与实验组相比差异具有统计学意义（P<0.05 - 0.001）。健康尺神经（H组）的轴突计数为1849±362。受损尺神经的轴突计数在B组为1447±579/78%，C组为1051±367/57%，D组为567±230/31%。
供体神经应保持健康以获得最佳效果。粗大神经（如尺神经）即使损伤且至少75%的轴突保留，仍可能有效地用于移位。相比之下，细小神经（如肋间神经）即使75%的轴突保留，一旦受损也会被视为次优的供体神经。
