Restoration of Elbow Flexion by Transfer of the Phrenic Nerve to Musculocutaneous Nerve after Brachial Plexus Injuries

Traumatic brachial plexus injuries are a devastating injury that results in partial or total denervation of the muscles of the upper extremity. Treatment options that include neurolysis, nerve grafting, or neurotization (nerve transfer) has become an important procedure in the restoration of function in patients with irreparable preganglionic lesions. Restoration of elbow flexion is the primary goal in treating patients with severe brachial plexus injuries. Nerve transfers are used when spinal roots are avulsed, and proximal stumps are not available. In the present study, we analyze the results obtained in 20 patients treated with phrenic–musculocutaneous nerve transfer to restore elbow flexion after brachial plexus injuries. A consecutive series of 25 adult patients (21 men and 4 women) with a brachial plexus traction/crush lesion were treated with phrenic–musculocutaneous nerve transfer, but only 20 patients (18 men and 2 women) were followed and evaluated for at least 2 years postoperatively. All patients had been referred from other institutions. At the initial evaluation, eight patients received a diagnosis of C5-6 brachial plexus nerve injury, and in the other 12 patients, a complete brachial plexus injury was identified. Reconstruction was undertaken if no clinical or electrical evidence of biceps muscle function was seen by 3 months post injury. Functional elbow flexion was obtained in the majority of cases by phrenic–musculocutaneous nerve transfer (14/20, 70%). At the final follow-up evaluation, elbow flexion strength was a Medical Research Council Grade 5 in two patients, Grade 4 in four patients, Grade 3 in eight patients, and Grade 2 or less in six patients. Transfer involving the phrenic nerve to restore elbow flexion seems to be an appropriate approach for the treatment of brachial plexus root avulsion. Traumatic brachial plexus injury is a devastating injury that result in partial or total denervation of the muscles of the upper extremity. Treatment options include neurolysis, nerve grafting, or neurotization (nerve transfer). Neurotization is the transfer of a functional but less important nerve to a denervated more important nerve. It has become an important procedure in the restoration of function in patients with irreparable preganglionic lesions. Restoration of elbow flexion is the primary goal in treating patients with severe brachial plexus injuries. Nerve transfers are used when spinal roots are avulsed, and proximal stumps are not available. Newer extraplexal sources include the ipsilateral phrenic nerve as reported by Gu et al. (Chin Med J 103:267–270, 1990) and contralateral C7 as reported by Gu et al. (J Hand Surg [Br] 17(B):518–521, 1992) and Songcharoen et al. (J Hand Surg [Am] 26(A):1058–1064, 2001). These nerve transfers have been introduced to expand on the limited donors. The phrenic nerve and its anatomic position directly within the surgical field makes it a tempting source for nerve transfer. Although not always, in cases of complete brachial plexus avulsion, the phrenic nerve is functioning as a result of its C3 and C4 major contributions. In the present study, we analyze the results obtained in 20 patients treated with phrenic–musculocutaneous nerve transfer to restore elbow flexion after brachial plexus injuries.     

荧光逆行示踪法定位神经端侧缝合后再生来源的实验研究

目的 应用荧光逆行示踪法研究神经端.侧缝合修复臂丛神经损伤的有效性及再生神经的脊髓定位.方法 雌性SD大鼠24只,随机分为4组,造成臂丛神经上干损伤模型,分别以膈神经、同侧颈,神经根为供体神经,按照端.侧和端.端两种缝合方式修复肌皮神经.术后3个月,对大鼠肌皮神经和供体神经分别采用真蓝和双脒基黄进行逆行示踪.3、7、14 d后进行灌注固定,取颈段脊髓连续切片,荧光显微镜观察.结果 各观察点背根节及脊髓前角均出现荧光标记细胞,并逐渐增多.以同侧颈,为供体神经组,标记细胞仅出现在该节段,而以膈神经为供体神经组,标记细胞出现在颈_(3-5)节段.端一侧缝合组在相应脊髓前角或背根神经节出现,同时具有两种荧光剂的双标细胞或在同一脊髓节段同时出现分别以两种荧光剂标记的单标细胞.结论 采用不同供体神经进行端.侧缝合联合神经移植修复臂丛神经可使神经再生,荧光逆行示踪可以准确定位端.侧缝合后再生神经的来源.     

Neurotization via the spinal accessory nerve in complete paralysis due to multiple avulsion injuries of the brachial plexus

The authors report their experience with 21 cases of neurotization via the spinal accessory nerve for multiple nerve root avulsion injuries of the brachial plexus associated with total paralysis of the upper limb. They performed microneuroanastomoses with interposed cable nerve grafts between the spinal accessory nerve taken in the supraclavicular fossa and the musculocutaneous nerve at its entrance into the biceps muscle. Surgical indications depend on the accurate diagnosis of spinal nerve root avulsion, especially C5. The anatomicosurgical basis of this technique is as precise as are the indications. As many as two-thirds of the patients with a neurotized musculocutaneous nerve can be expected to achieve strength of at least Grade 3 on late muscle testing. Nevertheless, these results are always inferior to those obtainable when grafting is performed with carefully selected unavulsed C5 or C6 spinal nerve root fibers in the intervertebral foramina. Therefore, neurotization via donor nerves extrinsic to the plexus should only be considered as a second-choice intervention.     

同侧颈7神经根移位治疗臂丛上千根性撕脱伤的实验研究

目的 实验性比较同侧C7神经根全根移位与其他3种方法治疗臂丛上千根性撕脱伤的疗效.方法 120只SD大鼠建立上千根性撕脱伤模型后随机等分为4组,每组30只.(1)A组:同侧C7移位至上千+副神经至肩胛上神经;(2)B组:Oberlin手术(尺神经一束移位至肱二头肌支)+副神经至肩胛上神经+桡神经肱三头肌长头支至腋神经前支;(3)C组:膈神经移位至上千前股+副神经至肩胛上神经+颈丛运动支至上千后股;(4)D组:膈神经移位至上千前股+副神经至肩胛上神经,不作腋神经修复.术后3、6和12周每组取10只大鼠作Ochiai评分、Barth足错步试验、Terzis梳头试验及神经再生指标的榆测.结果 术后3周,A组3项行为学检测指标与3个对照组差异无统计学意义(P>0.017),腋神经电生理指标均显著优于3个对照组,其余各项腋神经及三角肌组织学指标均显著优于C组和D组,但与B组比较差异无统计学意义.A组除肌皮神经再生有髓神经纤维通过率显著优于C组外,其余肌皮神经及肱二头肌的电牛理与组织学检测指标与3个对照组比较差异无统计学意义.12周时,A组各项行为学观察、几乎全部腋神经和三角肌的电生理与组织学检测以及部分肌皮神经和肱二头肌的电生理与组织学检测指标均已显著优于3个对照组.结论 同侧C7神经根移位对治疗臂丛上千根性撕脱伤的实验性疗效显著.     

Brachial plexus anatomy

The brachial plexus may be visualized simply as beginning with five nerves and terminating in five nerves. It begins with the anterior rami of C5, C6, C7, C8, and the first thoracic nerve. It terminates with the formation of the musculocutaneous, median, ulnar, axillary, and radial nerves. The intermediate portions are displayed in sets of threes: three trunks are formed, followed by three divisions, then three cords. Each trunk gives rise to two divisions and each cord gives rise to two branches. The lateral cord divides into the musculocutaneous nerve and the lateral branch of the median nerve. The medial cord divides into the medial branch of the median nerve and the ulnar nerve. The posterior cord divides into the axillary and the radial nerves. The anatomy of the brachial plexus can be confusing, especially because of frequent variations in length and caliber of each of its components.     

膈神经移位接上干前股的解剖与临床研究

目的 通过对肌皮神经肱二头肌肌支的解剖学研究,为臂丛损伤后设计应用膈神经移接手臂丛上干前肌恢复屈肘功能的新术式。方法 对１０具２０侧尸体上肢的肱二头肌肌支作逆行解剖,观察其在上干前肌内的定位。对２１例臂丛损伤患者,将膈神经移接于上干前肌,并观察其疗效。结果 解剖学研究：肱二头肌肌支位于上干前股前外侧及前正中束组,其横截面积占上干前股横截面积的３４％ＲＲ。２１例患者屈肘功能恢复的总有效率达８０．９５     

Nerve transfer for treatment of brachial plexus injury：comparison study between the transfer of partial median and ulnar nerves and that of phrenic and spinal accessary nerves

Objective:To compare the effect of using partial median and ulnar nerves for treatment of C5-6 orC5-7 avulsion of the brachial plexus with that of using phrenic and spinal accessary nerves.Methods:The patients were divided into 2groups randomly according to different surgical procedures.Twelve cases were involved in the first group.The phrenic nerve was transferred to the musculocutaneous nerve or through a sural nerve graft,and the spinal accessary nerve was to the suprascapular nerve.Eleven cases were classified into the second group.A part of the fascicles of median nerve was transferred to be coapted with the motor fascicle of musculocutaneous nerve and a part of fascicles of ulnar nerve was transferred to the axillary nerve.The cases were followed up from 1to 3years and the clinical outcome was compared between the two groups.     

The use of thoracodorsal nerve transfer in restoration of irreparable C5 and C6 spinal nerve lesions.

There are only a few reports on the use of thoracodorsal nerve (TDN) transfer to the musculocutaneous or axillary nerves in cases of directly irreparable brachial plexus injuries. In this study, we analysed outcome and time-course of recovery in correlation with recipient nerves and type of nerve transfer (isolated or in combination with other collateral branches) for 27 patients with transfer to the musculocutaneous or axillary nerves. Using this nerve as donor, we obtained useful functional recovery in all 12 cases for the musculocutaneous nerve, and in 14 (93.3%) of 15 nerve transfers for the axillary nerve. Although, we found no significant statistical difference between analysed patients according to the percentage of recoveries and mean values, we established a better quality and shorter time of recovery for the musculocutaneous nerve. According to obtained results, we consider that transfer may be a valuable method in reconstruction after directly irreparable C5 and C6 spinal nerve lesions.     

Nerve repairs for traumatic brachial plexus palsy with root avulsion

Thirty-six patients with traumatic brachial plexus lesions and root avulsions were treated surgically between 1972 and 1986 and were followed for more than 24 months (average, 42.6 months). Neurotization of the musculocutaneous nerve with intercostal nerves or the spinal accessory nerve resulted in satisfactory elbow flexion in 21 of the 33 cases (64%). Combined nerve repairs (i.e., intercostal and spinal accessory neurotization of the terminal branch of the brachial plexus in combination with nerve grafts from the upper spinal nerves of the brachial plexus) created a useful function in at least one functional level of the upper limb for 11 of the 15 cases so treated. Nerve repairs resulted in stability of the shoulder and elbow function controllable with a sensible hand for patients with root avulsion injury of the brachial plexus.     

The rat brachial plexus and its terminal branches: An experimental model for the study of peripheral nerve regeneration

Despite the introduction of microsurgical techniques into clinical practice, the results of surgical procedures involving the brachial plexus and peripheral nerves are still far from spectacular. We therefore studied the rat brachial plexus and its terminal branches in 203 rats. Detailed anatomic and morphologic analyses of the biceps brachii and musculocutaneous nerve, finger flexors, flexor carpi radialis, and the median nerve were performed. Various sources of conventional and vascularized nerve grafts were explored. After musculocutaneous nerve section or median nerve section, there were no articular contractures or automutilations, which constitutes an advantage for these experimental models over the sciatic nerve model. The brachial plexus and its terminal branches provide a good experimental model which can be used to assess the development and normal control of muscle function, examine the mechanisms underlying functional recovery, and test the effects of treatments to enhance recovery. © 1995 Wiley-Liss, Inc.     

Postoperative brachial plexus neuropathy after total knee replacement under spinal anaesthesia

We describe a case of idiopathic postoperative brachial plexus neuropathy. A 68-yr-old man underwent elective total knee replacement under spinal anaesthesia. Two days after surgery, there was sensory loss and weakness in the right forearm and hand, which suggested an ulnar nerve neuropathy. Two weeks later the patient complained of a dull ache between the scapulae, followed by a burning sensation in the forearm and severe pain in the elbow. A diagnosis of brachial plexus neuropathy was made based on clinical examination and nerve conduction studies. The pain disappeared after a few months, although weakness of the right arm persisted 9 months later. The differential diagnosis between brachial plexus neuropathy and ulnar nerve neuropathy is important, as the prognosis of brachial plexus neuropathy is generally good.      

大鼠肱肌肌支的脊髓神经根定位

目的 比较逆行示踪法及肌电图检测法在定位肱肌肌支及肱肌脊髓神经根起源中的价值,并探讨将肌电图检测法运用于定位人类肌皮神经肱肌肌支脊髓神经根起源的可能性.方法 在大鼠臂丛神经根切断-保留模型中运用神经元逆行示踪法定位肱肌肌支及肱肌的脊髓神经根起源;通过分析刺激大鼠各臂丛神经根时肱肌记录到的CMAP指标定位肱肌肌支及肱肌的脊髓神经根起源.结果 大鼠桡神经肱肌肌支的运动纤维主要来源于C7神经根,大鼠肌皮神经肱肌肌支的运动纤维主要来源于C5、6神经根;在定位大鼠肱肌的脊髓神经根起源时,肌电图法与逆行示踪法的检测结果基本一致.结论 通过分析逆行示踪和肌电图检测的结果,能够精确定位大鼠特定神经、肌肉的脊髓神经根来源;在临床研究中,肌电图检测法可以用于定位人类肌皮神经肱肌肌支的脊髓神经根起源.     

胸腔镜视下切取膈神经移位治疗臂丛神经损伤的临床应用报告

目的 首创在胸腔镜视下切断膈神经远端移接于肌皮神经的新术式。方法 临床应用５例。在胸腔镜视下于人膈肌近端切断膈神经,游离在胸腔内的膈神经全长。膈神经自锁骨上抽出经皮下引至肌皮神经３例,于锁骨下自第二肋间引起移位于肌皮神经２例。移接于肌皮神经主干２例,移接于肌皮神经肌支３例。首例于术后１１０ｄ,检测肱二头肥肥电图出现再生电位。结论 胸腔镜视下切并游离胸腔内膈神经全长,是膈神经移位术中切取膈神经的最佳     

Transfer of the medial pectoral nerve: myth or reality?

OBJECTIVE: Transfer of the medial pectoral nerve is one of the most controversial procedures used to reinnervate the paralyzed upper arm because of brachial plexus spinal nerve root avulsion or directly irreparable proximal lesions of spinal nerves. The purpose of this study was to determine the value of this type of nerve transfer to the musculocutaneous and axillary nerves. METHODS: The 25 patients included in the study comprised 14 patients who had nerve transfer to the musculocutaneous nerve and 11 who underwent nerve transfer to the axillary nerve. These patients' functional recovery and the time course of their recovery were analyzed according to the type of transfer of one donor nerve or the donor nerve in combination with other donors. RESULTS: Useful functional recovery was achieved in 85.7% of patients who had nerve transfer to the musculocutaneous nerve and in 81.8% of patients who underwent nerve transfer to the axillary nerve. There was no significant difference in results with regard to the type of nerve transfer and which recipient nerves were involved. A strong trend toward better results after procedures involving the use of a donor nerve combined with other donors was observed, however. CONCLUSION: Our surgical results suggest that the transfer of the medial pectoral nerve to the musculocutaneous nerve and also to the axillary nerve may be a reliable and effective procedure.     

A surgical approach for concomitant spinal cord and brachial plexus surgery: an anatomical study

Spinal cord surgery is not the current treatment for brachial plexus avulsion injuries. However, several experimental and a few clinical cases have been reported with promising results. This surgical strategy in the near future, might prove to be useful. Different simultaneous anatomical approaches to the brachial plexus and spinal cord were studied in attempt to discover the best route to be used in the surgical reconstruction of avulsion lesions of the brachial plexus by spinal cord surgery. Eleven fresh subjects were used to compare: a) simultaneous dorsal approaches to the brachial plexus and spinal cord, b) the dorsal approach to the spinal cord and the anterior approach to the brachial plexus, c) a dorsal approach to the spinal cord combined with a dorsal approach through the triceps muscle to the terminal branches of the brachial plexus and d) a purely anterior approach to the spinal cord and brachial plexus. During the study, special attention was paid to the length of the grafts needed for repair, the possibility of entire exposure of the brachial plexus and the possibility of performing concomitant nerve transfers. As a result of the anatomical findings, we would suggest a dorsal approach to the spinal cord, suprascapular nerve and sometimes to the axillary nerve, combined with an anterior exposure to the brachial plexus in order to have the whole plexus explored and routine simultaneous nerve transfers performed. In selected cases, with limited root injuries, the dorsal approach to the brachial plexus and spinal cord and the anterior approach to the brachial plexus and spinal cord might be of interest.     

Transfer of pectoral nerves to the musculocutaneous nerve in obstetric upper brachial plexus palsy

OBJECTIVE: To investigate the results of transfer of pectoral nerves to the musculocutaneous nerve for treatment of obstetric brachial palsy. METHODS: In 25 cases of obstetric brachial palsy (20 after breech deliveries), branches of the pectoral nerve plexus were transferred directly to the musculocutaneous nerve. For all patients, the nerve transfer was part of an extended brachial plexus reconstruction. Results were tested both clinically and with the Mallet scale, at a mean follow-up time of 70 months (standard deviation, 34.3 mo). RESULTS: There were two complete failures, which were attributable to disconnection of the transferred nerve endings. The results after transfer were excellent in 17 cases and fair in 5 cases. Steindler flexorplasty improved elbow flexion for three patients. CONCLUSION: Transfer of pectoral nerves to the musculocutaneous nerve for treatment of obstetric upper brachial palsy may be effective, if the specific anatomic features of the pectoral nerve plexus are sufficiently appreciated.     

Nerve transfer in brachial plexus traction injuries.

Brachial plexus palsy due to traction injury, especially spinal nerve-root avulsion, represents a severe handicap for the patient. Despite recent progress in diagnosis and microsurgical repair, the prognosis in such cases remains unfavorable. Nerve transfer is the only possibility for repair in cases of spinal nerve-root avulsion. This technique was analyzed in 37 patients with 64 reinnervation procedures of the musculocutaneous and/or axillary nerve using upper intercostal, spinal accessory, and regional nerves as donors. The most favorable results, with an 83.8% overall rate of useful functional recovery, were obtained in patients with upper brachial plexus palsy in which regional donor nerves, such as the medial pectoral, thoracodorsal, long thoracic, and subscapular nerves, had been used. The overall rates of recovery for the spinal accessory and upper intercostal nerves were 64.3% and 55.5%, respectively, which are significantly lower. The authors evaluate the results of nerve transfer and analyze different donor nerves as factors influencing the prognosis of surgical repair.     

Stretching of the brachial plexus in rabbits

The brachial plexus of rabbits was stretched until mechanical failure. The level and site of rupture varied according to the direction of the stretching force. Upward and lateral traction of the forelimbs caused spinal nerve-root avulsions combined with nerve-trunk ruptures distal to the dorsal root ganglions. In such tractions the C5 nerves consistently exhibited postganglionic nerve-trunk rupture. The C6, C7, and C8 nerves had root avulsions. The T1 nerve was avulsed from the spinal cord in 7 cases out of 10; the other 3 cases had postganglionic nerve-trunk rupture. Downward traction of the forelimbs caused nerve avulsions from the scapulohumeral muscles innervated by the terminal branches of the brachial plexus and peripheral nerve ruptures in the course of the arm. The force producing trunk rupture of the C6 nerve was twice as great as that for root avulsion. The required stain was similar for nerve trunk rupture and root avulsion.     

Stretching of the brachial plexus in rabbits

The brachial plexus of rabbits was stretched until mechanical failure. The level and site of rupture varied according to the direction of the stretching force. Upward and lateral traction of the forelimbs caused spinal nerve-root avulsions combined with nerve-trunk ruptures distal to the dorsal root ganglions. In such tractions the C5 nerves consistently exhibited postganglionic nerve-trunk rupture. The C6, C7, and C8 nerves had root avulsions. The T1 nerve was avulsed from the spinal cord in 7 cases out of 10; the other 3 cases had postganglionic nerve-trunk rupture. Downward traction of the forelimbs caused nerve avulsions from the scapulohumeral muscles innervated by the terminal branches of the brachial plexus and peripheral nerve ruptures in the course of the arm. The force producing trunk rupture of the C6 nerve was twice as great as that for root avulsion. The required stain was similar for nerve trunk rupture and root avulsion.     

Diagnosis and surgery of brachial plexus injuries

The surgical outcome of traumatic injuries of the brachial plexus (BP) depends on the following parameters: 1) accurate preoperative diagnosis of cervical root avulsion; 2) time interval between injury and surgery; 3) delicate handling of the nerve tissue; and 4) postoperative physiologic training. This report is based on a 15-year experience in brachial plexus surgery and is supported on the grounds of two major studies. In a prospective study, the authors controlled for the reliability of preoperative radiologic diagnosis by myelo-CT and MRI scans for 40 patients, to evaluate the integrity of the intraspinal cervical roots after brachial plexus injury. Surgical inspection via a cervical hemilaminectomy proved the accuracy of 85 percent and 52 percent of CT myelography and MRI, respectively. Retrospective statistical analyses were carried out of the long-term surgical results of 54 patients with traumatic injuries of the BP who received a grafting procedure between cervical roots C5 or C6 and the musculocutaneous nerve. Patients operated on up to 6 months after trauma showed a better result than patients operated on later than 12 months after trauma (p<0.05). In contrast, grafting between cervical root C5 or C6 and the use of different sural-graft sizes to reconstruct the musculocutaneous nerve demonstrated no statistically significant difference in the final outcome.