后入路副神经移位至肩胛上神经的应用解剖

目的 对斜方肌内的神经支配进行解剖学观察,为寻找副神经移位到肩胛上神经的最佳移位点和移位方式提供解剖依据.方法 选用成人尸体标本10具20侧.观察副神经在斜方肌内的行径及分支.并取不同水平副神经、肩胛上神经横断面制病理切片,计数各神经断面的神经纤维数,进行比较.结果 副神经在锁骨上2～3 cm进入斜方肌内,在肩胛冈中点前上方3～4 cm处,有来自颈丛的交通支加入后形成终末支.副神经的神经纤维计数:入斜方肌处(A点)为(1245±46)条,颈丛的交通支汇入前(B点)为(830±36)条,汇入后(C点)为(1074±38)条.结论 (1)副神经在与颈丛交通支合干后H-G段内的各断点,是副神经的最佳移位点.(2)后进路副神经移位术不影响斜方肌上部神经支配,充分利用了颈丛交通支,且缩短了神经再生距离,值得推广.     

A cadaveric study of the motor nerves to the levator scapulae muscle

Understanding the surgical anatomic relationships of the motor nerves to the levator scapulae muscle is imperative for reducing postoperative shoulder dysfunction in patients undergoing neck dissection. To elucidate this relevant anatomy, cervical (C3, C4) and brachial (C5 via dorsal scapular nerve) plexi contributions to the levator scapulae were assessed with respect to posterior triangle landmarks in 37 human cadaveric necks. An average of approximately 2 (actual 1.92) nerves from the cervical plexus (range 1 to 4 nerves) emerged from beneath the posterior border of the sternocleidomastoid muscle in a cephalad to caudad progression to enter the posterior triangle of the neck on their way to innervating the levator scapulae. These cervical plexus contributions exhibited a fairly regular relationship to the emergence of cranial nerve XI and the punctum nervosum along the posterior border of the sternocleidomastoid muscle. After emerging from the posterior border of the sternocleidomastoid to enter the posterior triangle of the neck, cervical plexus contributions to the levator scapulae traveled for a variable distance posteriorly and inferiorly, sometimes branching or coming together. Ultimately these nerves crossed the anterior border of the levator scapulae as 1 to 3 nerves (average 1.94) in a regular superior to inferior progression. The dorsal scapular nerve from the brachial plexus exhibited highly variable anatomic relations in the inferior aspect of the posterior triangle, and was found to penetrate or give branches to the levator scapulae in only 11 of 35 neck specimens. We have found that the levator scapulae receives predictable motor supply from the cervical plexus. Our data elucidate surgical anatomy useful to head and neck surgeons. (Otolaryngol Head and Neck Surg 1997;117:671-80.)     

A study of sternocleidomastoid muscular atrophy after modified neck dissection

To elucidate the conditions of atrophy in the sternocleidomastoid muscle (SCM) after modified neck dissection (MND), we tried to scrutizine the atrophic regions in the SCM and determine the cause of atrophy, by electromyography in 40 patients with SCM atrophy following MND. We also examined the detailed anatomy of the SCM in 40 cadavers. Atrophy was observed in the caudal portion of the SCM in 90% of the patients. Electromyographic examination revealed neurogenic atrophy in 24 patients, ischemic atrophy in 11, and a mixing of both types in 5. The SCM was found to be innervated by the spinal accessory nerve (SAN) and the SCM branch of the cervical nerve. The main artery feeding the cranial half of the SCM was a branch of the occipital artery (Oc) or the external carotid artery (Ex), and the auxiliary artery was a branch of the posterior auricular artery (Ap). The main artery feeding the caudal half of the SCM was a branch of the superior thyroidal artery (St), and the auxiliary artery was a branch of the subclavian artery (Sc). Postoperative SCM atrophy is attributed to damage of the feeding artery in the SCM caudal portion and local damage in the nerve fibers running through the SCM. To prevent this type of atrophy, it is important to carefully handle this muscle itself and protect the nerve fibers running through it, as well as to conserve the SCM branches of the St and Sc.     

The anatomic branch pattern of the axillary nerve

The purpose of this study is to determine the surgical anatomy and innervation pattern of the branches of the axillary nerve and discuss the clinical importance of the presented findings. We dissected 30 shoulders in 15 fixed adult cadavers under a microscope through anterior and posterior approaches. The axillary nerve was examined in 2 segments in relation to the underlying subscapularis muscle. The axillary nerve gave off no branches in the first segment in 85% of cases. When the posterior approach was used, the axillary nerve and its branches were observed to be in a triangular-shaped area. The mean distance from the posterolateral corner of the acromion to the axillary nerve and its branches was 7.8 cm. In all cases, the posterior branch of the axillary nerve gave off its first muscular branch to innervate the teres minor. The joint branch of the axillary nerve was observed to branch out in 3 different patterns. The acromial and clavicular parts of the deltoid muscle were observed to be innervated from the anterior branch of the axillary nerve in all cases. The posterior part of the deltoid muscle was observed to be innervated in 3 different patterns. The posterior part of the deltoid was innervated from the branch or branches coming only from the posterior branch in 70% of cases, from the anterior and posterior branches in 26.7% of cases, and from the anterior branch in 3.3% of cases. The findings of this study are useful for identifying each of the branches of the axillary nerve and have implications for surgeries related with selective innervation.     

Surgical anatomy of spinal accessory nerve: is trapezius functional deficit inevitable after division of the nerve?

The course of spinal accessory nerve in the posterior triangle, the innervation of the sternocleidomastoid and trapezius muscles and the contributions from the cervical plexus were studied in 20 cadaveric dissections. The nerve was most vulnerable to iatrogenic injuries after leaving the sternocleidomastoid. Direct innervation of trapezius by cervical plexus branches was noted in five dissections, whereas connections between the cervical plexus and the spinal accessory nerve were observed in 19 dissections. These were usually under the sternocleidomastoid (proximal to the level of division of the nerve in nerve transfer procedures). Although the contribution from the cervical plexus to trapezius innervation is considered minimal, trapezius function can be protected in neurotization procedures by transecting the spinal accessory nerve distal to its branches to the upper position of trapezius.     

The anatomy of the pectoral nerves and their significance in brachial plexus reconstruction

Twenty-nine brachial plexuses from 13 embalmed and 5 fresh cadavers were examined under x3.5 loupe magnification to collect systematic and topographic anatomical data regarding the lateral and medial pectoral nerves. Additionally, nerve biopsy specimens were harvested in 5 fresh cadavers to obtain histomorphometric data. In all dissections the pectoral nerves exited at the trunk level as 3 distinct nerves. The superior pectoral nerve (from the anterior division of the superior trunk) commences just distal to the suprascapular nerve and courses laterally to innervate the lateral clavicular portion of the pectoralis major muscle (PM) with 2 to 4 branches. The middle pectoral nerve (from the anterior division of the middle trunk) courses distally and enters the infraclavicular fossa with 2 constant branches. The superficial branch terminates in the medial clavicular and upper sternal parts of the PM. The deep branch always forms a plexus with the medial pectoral or inferior pectoral nerve (from the anterior division of the inferior trunk), which courses at a right angle around the the lateral thoracic artery. From this plexus several branches terminate in the Pm. The branch to the lower aspect of the PM pierces the pectoralis minor muscle in two thirds of cases, whereas it passes its inferior border to reach the lower aspects of the PM with an average length of 15 cm in one third of cases. Knowledge of the detailed anatomy of the pectoral nerves, as outlined in this study, clarifies the obscure anatomic relationship of the lateral and medial pectoral nerves and allows easy intraoperative location of the medial pectoral nerve at the exit of the lateral thoracic artery. The length of the inferior pectoral nerve, the number of motor axons, and the anatomical proximity of this nerve make it an expendable but powerful source of reinnervation to the musculocutaneous nerve in upper brachial plexus injuries.     

Selective denervation of the levator scapulae muscle: an amendment to the Bertrand procedure for the treatment of spasmodic torticollis

OBJECT: The purpose of this cadaveric study was to explore a modification to the Bertrand procedure for the treatment of spasmodic torticollis, namely the denervation of the levator scapulae (LS) muscle for laterocollis. METHODS: The authors performed a series of 9 cadaveric dissections. Five were done to identify the anterior innervation of the LS, and the remaining 4 were to identify the tendinous insertions of the LS onto the lateral masses of the cervical spine via a posterior approach. The nerve supply to the LS from the anterior divisions of the C-3 and C-4 nerve roots and the contribution from the dorsal scapular nerve were identified over the anterior surface of the muscle. RESULTS: The C-3 and C-4 nerve root branches were situated within 2 cm of each other and inferior to the punctum nervosum. The dorsal scapular contribution was clearly identified in 2 cadavers. Selective denervation of this muscle is possible through the same posterior triangle incision used for denervating the sternocleidomastoid muscle of its accessory nerve branches. This approach will be helpful in patients with laterocollis contralateral to the direction of chin turning. The authors compare this approach to the posterior approach for sectioning the insertions of the LS muscle onto the C1-4 posterior tubercles. The latter approach is appropriate for ipsilateral laterocollis. CONCLUSIONS: The posterior triangle approach for denervating the LS muscle is a safe and easy addition to the Bertrand procedure and can be helpful in selected cases of torticollis with a laterocollis component.     

Innervation of the trapezius muscle by the intra-operative measurement of motor action potentials

Although the surgical anatomy of the spinal accessory nerve and the cervical plexus has been extensively described, the exact motor innervation of the trapezius has been controversial. Attempts to resolve this question have involved anatomic or electrophysiologic studies in human embryos and animals. Extrapolation of the results to adult humans may not be correct. Accurate identification of muscle innervation is obtainable by intra-operative measurement of motor action potentials produced by direct stimulation of the accessory nerve and the cervical plexus. The study involved 14 patients undergoing supraomohyoid or modified neck dissections. Under direct vision, stimulating electrodes were placed on the identified nerves and motor action potentials, and latencies were recorded by surface electrodes placed over the three portions of the trapezius. In 13 patients, when the accessory nerve was stimulated, motor action potentials were obtained in 13 of 13 in the first portion, 11 of 13 in the second portion, and 10 of 13 in the third portion of the trapezius. In the last patient, the accessory nerve ended in the sternocleidomastoid muscle, and innervation of the trapezius was via C3 as demonstrated by motor action potentials. Responses when the roots of the cervical plexus were stimulated varied. Three patterns were seen: In the first group (seven patients), motor action potentials were distinct from those recorded when the accessory nerve was stimulated. Additionally, latencies were different from those of the accessory nerve. The second group (four patients) had motor action potentials that were similar to those obtained from stimulation of the accessory nerve, although their corresponding latencies were different. In two patients, no motor action potentials were recorded when the cervical plexus was stimulated. The results suggest that motor innervation of the trapezius is variable. The accessory nerve, when present, provides the most important input to the trapezius. Motor innervation from the cervical plexus is unpredictable, although it appears to be present in the majority of patient studies.     

Surgical anatomy of the dorsal scapular nerve

OBJECT: There is a paucity of literature regarding the surgical anatomy of the dorsal scapular nerve (DSN). The aim of this study was to elucidate the relationship of this nerve to surrounding anatomical structures. METHODS: Ten formalin-fixed human cadavers (20 sides) were dissected, and measurements made between the DSN and related structures. The nerve pierced the middle scalene muscle at a mean distance of 3 cm from its origin from the cervical spine and was more or less centrally located at this exit site. It lay a mean distance of 1.5 cm medial to the vertebral border of the scapula between the serratus posterior superior, posterior scalene, and levator scapulae muscles. It was found to have a mean distance of 2.5 cm medial to the spinal accessory nerve as it traveled on the anterior border of the trapezius muscle. The nerve intertwined the dorsal scapular artery in all specimens and was found along the anterior border of the rhomboid muscles. On 19 sides the DSN originated solely from the C-5 spinal nerve, and on one side it arose from the C-5 and C-6 spinal nerves. CONCLUSIONS: Knowledge of the anatomy of the DSN will aid the surgeon who wishes to explore and decompress this structure.     

Intraneural topography of the ulnar nerve in the cubital tunnel facilitates anterior transposition

The surgical management of cubital tunnel syndrome includes anterior transposition of the ulnar nerve. The success of all transposition procedures is dependent on placement of the nerve anterior to the medial epicondyle without tension. Fifteen cadaveric upper extremities underwent anterior transposition followed by anterior transposition with separation of the most proximal motor branches from the main ulnar nerve for a distance of 1, 2, and 3 cm. Proximal dissection of these motor branches achieved an average gain in distance from the epicondyle of 71%, with an average distance from the epicondyle of 3.6 cm. The intraneural topography of the ulnar nerve was studied in five additional cases. Cross-section analysis of the fascicular anatomy at 333 μm intervals along the length of the nerve with longitudinal reconstructions confirmed a safe dissection plane without interfascicular plexus formation. The most proximal motor branch in the forearm could be traced proximally an average of 6.7. cm within the nerve before interfascicular mingling occurred (range 6.0 to 7.5 cm). Thus, 6.0 cm represented the upper limit of safe proximal dissection in these nerves. Proximal separation may be performed without disruption of interfascicular plexus connections and will facilitate anterior transposition.     

Vulnerability of the spinal accessory nerve in the posterior triangle of the neck: a cadaveric study.

Injury to the accessory nerve results in an obvious shoulder droop, loss of shoulder elevation, and pain. Prevention of inadvertent injury to the accessory nerve is critical in neck dissection. No previous study, however, anatomically demonstrates the mechanism of the spinal accessory nerve traction injury. Anatomic determination of the location and course of the spinal accessory nerve may be helpful for a better understanding of the mechanism of the nerve injury. The accessory nerve courses obliquely across the posterior triangle on the surface of the levator scapula muscle and reaches the trapezius. The length of the spinal accessory nerve in the posterior triangle is 34.7+/- 6.3 mm. The nerve passes through the posterior border of the sternocleidomastoid muscle 50.7+/- 12.9 mm below the tip of the mastoid process and reaches the anterior border of the trapezius 49.8 +/- 5.9 mm above the clavicle. It makes a posterior angle of 73.1 degrees +/- 19.4 degrees, on average, relative to the posterior border of the sternocleidomastoid. When the shoulder is pulled down and the head is turned to the opposite direction, the spinal accessory nerve is stretched in the posterior triangle. In the posterior triangle, the nerve is vulnerable, since it is superficial and covered only by skin and subcutaneous fascia. Therefore, extreme caution should be taken with any surgical procedures in the posterior triangle. Traction injury of the spinal accessory nerve in the posterior triangle cannot be ignored.     

颈浅动脉岛状皮瓣在修复颌面颈部烧伤瘢痕中的应用

目的　探讨颈浅动脉岛状皮瓣的切取方法,观察用其修复颌面颈部瘢痕的临床效果。方法　解剖观测10例成年人体标本的颈浅动脉起源、走行、分支和分布,将颈浅动脉分为斜方肌肌前段、肌内段和肌后段3段。14例颌面颈部瘢痕挛缩患者行瘢痕切除后应用颈浅动脉岛状皮瓣修复,观察术后皮瓣成活及患者颈部活动恢复等情况。　结果　颈浅动脉肌前段长度为(5. 1±0. 4)cm,肌内段为(2. 1±0. 5)cm,肌后段为(4. 7±0. 7)cm.内侧肌皮穿支位于第7颈椎旁开(7. 3±0. 6)cm、肩胛冈上(3. 9±0. 7)cm处。本组患者修复皮瓣大小为(16. 0cm×7. 0cm)~(35. 0cm×12. 0cm),除1例皮瓣远端有约3. 0cm×1. 5cm的坏死外, 13例患者皮瓣完全成活。随访4个月—3年,效果满意。　结论　颈浅动脉岛状皮瓣切取方法简便,不需要行断蒂手术,是修复颌面颈部瘢痕挛缩畸形的较好选择。     

Long thoracic nerve: anatomy and functional assessment

BACKGROUND: The anatomy and function of the long thoracic nerve are not fully understood. The purposes of this study were to clarify the anatomy of the long thoracic nerve and to propose a clinical test to assess the function of the upper division of the long thoracic nerve. METHODS: The long thoracic nerve and the serratus anterior muscle were studied in fifteen fresh cadavera. Six patients had an operation to treat a brachial plexus injury, and the long thoracic nerve was electrically stimulated. The resulting shoulder motion was then observed. RESULTS: The long thoracic nerve was formed by branches arising from the C5, C6, and C7 nerve roots. The C5 and C6 branches joined beneath the scalenus medius muscle to form the upper division of the long thoracic nerve, which was located 1 cm posteriorly and superiorly to the upper trunk origin. The union of the upper division with the branch from C7 occurred caudally, in the axillary region. Two branches from the upper division of the long thoracic nerve to the upper portion of the serratus anterior muscle were consistently identified. After electrical stimulation of the upper division branches, shoulder protraction was observed. CONCLUSIONS AND CLINICAL RELEVANCE: In the supraclavicular region, the long thoracic nerve has a trajectory parallel to the brachial plexus, which is contrary to the schematic representation in most textbooks. The upper division of the long thoracic nerve can be assessed by the shoulder protraction test.     

Surgical anatomy of the spinal accessory nerve in the posterior triangle of the neck

OBJECTIVE: The major complication of neck dissection and surgery at the posterior triangle of the neck is severe disability of the shoulder or "shoulder syndrome", which results from spinal accessory nerve injury. Surgical landmarks of the nerve in this area were studied. METHODS: Fifty-six fresh Thai cadavers (112 necks) were dissected to identify the anatomical relationship of the spinal accessory nerve and its commonly used landmarks. RESULTS: The spinal accessory nerve was found within 3.6 cm (mean, 1.43 cm) above Erb's point. The distance between the spinal accessory nerve entering the trapezius muscle and the clavicle was between 2.6 cm and 6.9 cm (mean, 4.5 cm). CONCLUSION: Our data were different from those described in the literature. Reconsideration of these two important landmarks can help to minimize iatrogenic injury of the spinal accessory nerve.     

Evaluation of traumatic cervical nerve root injuries by intraoperative evoked potentials

OBJECTIVE: To evaluate intraoperative evoked potentials as a diagnostic tool in traumatic brachial plexus injuries. METHODS: Thirteen patients with traumatic brachial plexus injuries were investigated by intradural nerve root inspection (n = 28 roots) via cervical hemilaminectomy to assess or rule out nerve root avulsion from the spinal cord. Two to 8 weeks later, evoked potentials from neck and scalp were recorded after direct electrical nerve root stimulation close to the vertebral foramen during operative brachial plexus repair via an anterior (supraclavicular and infraclavicular) approach. Recordings were performed without and after full muscle relaxation. RESULTS: There was a clear relationship between the state of the root as documented by intradural root inspection and the result of intraoperative recording of evoked potentials: the absence of evoked muscle action potentials from neck muscles demonstrated a 100% sensitivity for anterior root lesions, whereas sensory evoked potentials from the scalp demonstrated a 100% sensitivity for posterior root lesions. Moreover, roots could be identified with preserved continuity that did not conduct, suggesting a nerve lesion in continuity. CONCLUSION: Intraoperative evoked muscle action potentials and sensory evoked potentials after electrical nerve root stimulation allow selective functional evaluation of anterior and posterior nerve roots in patients with traumatic brachial plexus injuries. The high sensitivity and reliability of this test obviate the need for additional diagnostic surgery.     

前臂内侧皮神经后支与肘管综合征手术切口的解剖关系

目的 观察肘部前臂内侧皮神经(medial antebrachial cutaneous nerve,MACN)后支的解剖特征,探讨在肘管综合征松解手术中防止其医源性损伤的方法.方法 解剖10具(20侧)成人上肢标本,并对12例肘管综合征手术患者,在肱骨内上髁远、近各8 cm范围内,观察NACN后支的数目、横跨角度并测定其与手术切口(内上髁前1 cm)的交汇部位.结果 32侧肢体共记录到62支MACN 后支,平均每侧肢体为1.9支.其中1支者8侧(25.0%,均位于内上髁远侧),2支者19侧(59.4%),3支者4侧(12.5%),4支者1侧(3.1%).位于内上髁下方者37支(59.7%),内上髁上方者25支(40.3%).这些后支与切口线的交角均大于45°,即皮神经是横向跨过切口线的.所有标本(100%)均至少有1支后支从内上髁远侧跨过切口线,其距内上髁的平均距离为[(2.9±2.3)cm,x-±s,下同];在68.8%的标本中至少有1支后支从内上髁近侧跨过切口线,其距内上髁的平均距离为(2.1±1.8)cm.结论 MACN后支至少有1支横跨肘管综合征的手术切口线,了解其位置关系并在皮下组织中仔细解剖分出保护,有助于避免误伤.     

Lumbar plexus and psoas major muscle: not always as expected

BACKGROUND AND OBJECTIVES: Conflicting definitions concerning the exact location of the lumbar plexus have been proposed. The present study was carried out to detect anatomical variants regarding the topographical relation between the lumbar plexus and the psoas major muscle as well as lumbar plexus anatomy at the L4-L5 level. METHODS: Sixty-three lumbar plexuses from 32 embalmed cadavers were dissected to determine the topographical relation between lumbar plexus and psoas major muscle. At the L4-L5 levels variability in the course of the femoral as well as obturator nerve were described. RESULTS: The lumbar plexus was situated within the psoas major muscle in 61 of 63 cases. In 2 of 63 cases the entire plexus was localized posterior to the psoas major muscle. In the 61 of 63 cases in which the lumbar plexus was situated within the psoas major muscle, emergence of the individual nerves most often occurred on the posterior or posterolateral surface. CONCLUSIONS: Our results synthesize contrasting assumptions in previous literature, by demonstrating that both locations of the lumbar plexus may be encountered in clinical practice: within and posterior to the psoas major muscle. However, the latter situation represents a minor variant. At the level of L4-L5 the femoral nerve, showing a remarkable degree of branching, as well as the obturator nerve, were found within the psoas major muscle in the vast majority of specimens.     

臂丛神经椎间孔处的显微解剖及其临床意义

研究臂丛神经根及所属交感神经结构。方法：对１５具３０侧尸体观察了臂丛神经根及所属交感神经结构。结果：（１）椎管内臂丛神经根结构脆弱。暴力作用容易损伤，且无残存臂丛神经根可供直接修复。（２）臂丛各神经根分出角与其前支分出角的差异，可能为臂丛不同损伤类型的形态学基础。（３）Ｃ５、Ｃ６后支容易受骨赘或腱性组织卡压引起颈痛。（４）Ｈｏｍｅｒ征虽可作为诊断臂丛下干根性撕脱伤的一种依据，但星状神经节和下交通支由于缺乏肌肉筋膜保护，在暴力作用下可能单独损伤，导致诊断的假阳性。结论：熟悉臂丛神经椎间孔处的显微解剖有助于临床对臂丛的诊治。