Anatomy and blood supply of the lower four cranial and cervical nerves: relevance to surgical neck dissection

This study is a continuation of previous work searching for possible anatomic reasons to explain variable and usually unpredictable postoperative pain and dysfunction after the same nerve losses with similar neck dissection operations. The study consisted of dissections of 19 deceased unpreserved elderly subjects arterially injected with dyed latex. Of the 19 subjects, 14 had brain stem and cervical spinal cord dissections, and all had neck dissections. The findings suggested two possible anatomic reasons for the pain and dysfunction: (i) The intracranial anatomy of the lower four cranial nerves, the glossopharyngeal (IX), the vagus (X), the spinal accessory (XI), and the hypoglossal (XII), was just as variable as the previously reported peripheral spinal accessory nerve plexus; and (ii) Both the intracranial and neck dissections indicated that the blood supply to the lower four cranial and cervical nerves, particularly to the brachial plexus, could be impaired by atherosclerosis and/or neuroforaminal impingement or operative loss. This loss of blood supply theoretically could result in ischemia as another possible cause of postoperative pain and dysfunction. It is concluded that because of the potential importance of each nerve and vessel, often unknown at operation, it is very important to spare as many of them as possible to avoid subsequent painful impairment.     

Long head of the triceps branch transfer to axillary nerve in C5, C6 brachial plexus injuries: anterior approach

Shoulder abduction is a very complex movement and quite important for upper limb function, as more distal functions depend on a stable shoulder, especially in C5, C6 brachial plexus injuries. Various studies in the literature have emphasized the importance of improved functional outcome and shoulder reanimation with concomitant neurotization of suprascapular nerve and axillary nerve in C5, C6 brachial plexus injuries. A number of approaches to axillary nerve transfer in brachial plexus injuries have been reported. The author describes an innovative anterior deltopectoral approach for axillary nerve transfers in five patients with C5, C6 brachial plexus injuries. The spinal accessory nerve was neurotized with the suprascapular nerve through a transverse supraclavicular incision. The axillary nerve and the long head of the triceps branch were identified through the anterior deltopectoral approach and neurotized at the posterior cord level. This approach gives easy access to other donors such as the medial pectoral, thoracodorsal, and median and ulnar nerves. Oberlin's transfer was also performed for elbow flexion by extending the deltopectoral incision. The regained shoulder active abduction (M5) averaged 120 degrees and active external rotation averaged 65 degrees at the final follow-up of 26 months (average). This anterior deltopectoral approach is an excellent alternative for axillary nerve transfer in brachial plexus injuries and produces results comparable with those of other approaches. All brachial plexus surgeons must understand the anatomy and the relationship of the axillary nerve to the surrounding structures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.     

Management of iatrogenic injury to the spinal accessory nerve

Spinal accessory nerve injury results in a debilitating shoulder dysfunction. The trapezius is a major suspensory muscle of the shoulder girdle, and paralysis results in chronic pain and debility from disruption of synchronous scapulohumeral rhythm. This injury usually follows a simple posterior triangle lymph node biopsy and is treatable if appropriate measures are taken in a timely fashion. A major pitfall in early management is either failure to recognize or acknowledge the injury or hoping that it will resolve with conservative treatment. Variation of innervation of the trapezius alters clinical presentation and can make diagnosis difficult. We present a series of six patients with iatrogenic spinal accessory nerve injury following a neck node biopsy. Pain was the most common presenting symptom, and a loss of sustained abduction was the most common physical sign. Three patients had a primary nerve repair and the other three patients had nerve grafting. Maximum recovery time ranged from 4 to 10 months. All patients had varying degrees of recovery of motor function, and all six patients were 100 percent painfree. An algorithm for the management of this distressing condition emphasizes the importance of early referral and highlights the pitfalls in making an accurate diagnosis. Whereas conservative therapy is less predictable and needs careful selection, it also runs the risk of delaying a more effective surgical management. Early operative intervention is more definitive and has the best functional results. Prevention is key and is best achieved by avoiding unnecessary biopsies of the posterior triangle lymph node. When operating, knowledge of posterior neck anatomy and judicious use of the bipolar cautery and magnifying loupes are essential in preventing this problem.     

不同磁共振腰骶丛神经成像序列的临床研究

目的:比较周围神经背景信号抑制弥散加权成像(diffusion-weighted neuroimag ing with background signal suppression,DWIBS)、选择性激励技术(principle of selective excitation technique,PROSET)及三维短时反转恢复(3D Short Term Inversion Recovery,3D STIR)序列在腰骶部脊神经成像中的不同表现,探讨其对腰骶部病变的临床应用价值。方法:对29名正常志愿者及42例腰骶丛病变损伤患者行磁共振腰骶丛神经成像,包括DWIBS序列,PROSET及3D STIR序列。对DWIBS及3D STIR原始图像行最大信号强度投影(MIP)后处理重建,对志愿者组及病变组所得图像质量分级并分别进行统计分析,评价三种高场强磁共振腰骶丛神经成像序列在正常组及病变组的显示效果。结果:在正常志愿者组中,三种高场强磁共振腰骶丛神经成像序列均可显示脊神经根、神经节等解剖细节,对于腰4、5脊神经的显示,三者的图像分级差异不具有统计学意义。在腰2、3脊神经成像中,三者图像质量分级的差异具有统计学意义(P0.05)。在病例组中,经秩和检验三组组间显示效果不完全相同,P0.05,差异有统计学意义。进行两两比较,DWIBS与3D SITR序列,其差异具有统计学意义(P0.01)。PROSET与3D STIR序列,差异具有统计学意义(P0.01)。而DWIBS与PROSET图像质量分级差异无明显统计学差异。结论:DWIBS、PROSET、3DSTIR序列作为常规序列的补充,均可完整的显示腰骶神经的解剖细节,而DWIBS及PROSET序列对背景组织的抑制更加充分,更利于观察神经的走行变化、判断神经受损部位及范围。DWIBS序列MIP后处理图像实现了对腰骶神经的多方位多角度旋转观察,为术前制定手术方案提供可靠的影像学依据,弥补了常规磁共振序列的不足。     

HEADACHE OF EXTRACRANIAL ORIGIN

The cervical spine, usually regarded as a supporting structure for the head, is also an important viaduct of vessels and nerves which must function with little clearance in a congested and moving space bounded by bone. Pressure in this viaduct is an important cause of headache.The cervical foramina although apparently roomy, are constricted by cartilage, by the vertebral artery and its adnexae, and by the lateral intervertebral joints. Osteophytosis, swelling or adhesion in this constricted space almost inevitably causes painful vascular or neural disorder.In certain postures of the neck the vertebral artery is constricted or even occluded. Traction or sprain may likewise cause headache through disturbance of the vertebral arterial nerves, the posterior cervical autonomic system or the spinal accessory nerves which originate in delicate filaments from all points of the cervical spinal cord.A syndrome described by Skillern—migraine-like suboccipital and retro-orbital headache—is due to disturbance of the second cervical nerve, which communicates with the first division of the trigeminal nerve.Headache due apparently to a minor scalp contusion may really be due to irritation of a trigger area at the site of an old scalp injury.     

Muscles that act on glabellar skin: a closer look

The coronal incision forehead lift became a component of the face-lift procedure 35 years ago and increased the cosmetic benefit for the facial aesthetic surgery patient. Later, this enhanced cosmetic effect achieved from eyebrow resuspension was complemented by treatment of the glabellar skin lines by modifying corrugator supercilii and procerus muscle function through the same coronal incision. In recent years, newer procedures for treating the corrugator supercilii and procerus muscles by using endoscopy or limited incision techniques have eliminated the need for the coronal incision. With these newer techniques has come a renewed interest in the surgical anatomy of the muscle complex that acts on glabellar skin. This study was designed to examine the current understanding of the anatomy of these muscles and to resolve misconceptions and controversy concerning them. Fresh cadaver dissections and simulated muscle action studies done on the glabellar musculature of four specimens were correlated with nerve blockade studies performed in 10 subjects on the temporal and zygomatic branches of the facial nerve. The presence of the depressor supercilii muscle as a distinct entity was confirmed. The little-appreciated oblique head of the corrugator supercilii muscle was identified. The conclusions from this study suggest that the transverse head of the corrugator supercilii muscle produces the vertical component of the glabellar skin line and also contributes to the formation of the oblique component of the glabellar skin line. The oblique head of the corrugator supercilii muscle, the depressor supercilii muscle, and the medial head of the orbital portion of the orbicularis oculi muscle all appear to depress the medial head of the eyebrow and contribute to the formation of the oblique glabellar skin line. The nerve block study provided evidence that the zygomatic branch of the facial nerve supplies the three medial eyebrow depressor muscles, which opens the possibility for future nerve ablation techniques to control the action of the medial eyebrow depressor muscle group. This nerve block study also supports the concept of "physiologic" elevation of the medial eyebrow as an effective component of foreheadplasty.     

The harvest and clinical application of the superficial peroneal sensory nerve for grafting motor and sensory nerve defects.

Potential donor nerves for autografting are finite and usually limited to cutaneous nerves of the extremities. The superficial peroneal nerve is the major lateral branch of the common peroneal nerve that innervates the peroneus longus and brevis muscles and provides sensation to the lateral aspect of the lower leg and the dorsal foot. It has generally been overlooked as a potential donor of nerve autografts. Cadaver dissections were performed on 10 fresh lower extremity specimens to investigate the anatomic characteristics of the superficial peroneal nerve and to refine a harvesting technique for the nerve. Thirty-one patients underwent nerve grafting of 39 upper and lower extremity nerves using the superficial peroneal donor. There were nine median nerves, four ulnar nerves, two radial nerves, two brachial plexus lesions, 16 digital nerves, and six lower extremity nerves grafted. The superficial peroneal nerve provided a consistently long donor, comparable in length to the sural nerve. The anatomic pattern is consistent, the patient positioning is simple, the surgical harvesting technique is straightforward, and the donor defect is acceptable. The superficial peroneal nerve provides a safe and valuable donor nerve, particularly in cases where multiple or very long nerve grafts are required.     

The suprascapular nerve as re-interpreted by its communication with the phrenic nerve.

A particular nerve bundle which may be called phrenicosuprascapular communication is, although only rarely, met with in various forms in man. By teasing, fibres of this communication are revealed to belong to the most anterior components of the brachial plexus, being closely associated with anterior nerves such as the phrenic, accessory phrenic, subclavius and even pectoralis. It is, therefore, obvious that the nervus suprascapularis conveys anterior fibres. It may be interpreted that the anteriormost nerve fibres may be separated from the main cord(s) and form an irregular network or plexus for themselves. It should be stressed that the n. suprascapularis consists of all the anterior components of the brachial plexus and that this is an anterior nerve.     

Free anterolateral thigh flap for reconstruction of head and neck defects following cancer ablation

Thirty-seven consecutive free anterolateral thigh flaps in 36 patients were transferred for reconstruction of head and neck defects following cancer ablation between January of 1997 and June of 1998. The success rate was 97 percent (36 of 37), with one flap lost due to a twisted perforator. The anatomic variations and length of the vascular pedicle were investigated to obtain better knowledge of anatomy and to avoid several surgical pitfalls when it is used for head and neck reconstruction. The cutaneous perforators were always found and presented as musculocutaneous or septocutaneous perforators in this series of 37 anterolateral thigh flaps. They were classified into four types according to the perforator derivation and the direction in which it traversed the vastus lateralis muscle. In type I, vertical musculocutaneous perforators from the descending branch of the lateral circumflex femoral artery were found in 56.8 percent of cases (21 of 37), and they were 4.83 +/- 2.04 cm in length. In type II, horizontal musculocutaneous perforators from the transverse branch of the lateral circumflex femoral artery were found in 27.0 percent of cases (10 of 37), and they were 6.77 +/- 3.48 cm in length. In type III, vertical septocutaneous perforators from the descending branch of the lateral circumflex femoral artery were found in 10.8 percent of cases (4 of 37), and they were 3.60 +/- 1.47 cm in length. In type IV, horizontal septocutaneous perforators from the transverse branch of the lateral circumflex femoral artery were found in 5.4 percent of cases (2 of 37). They were 7.75 +/- 1.06 cm in length. The average length of vascular pedicle was 12.01 +/- 1.50 cm, and the arterial diameter was around 2.0 to 2.5 mm; two accompanying veins varied from 1.8 to 3.0 mm and were suitable for anastomosis with the neck vessels. Reconstruction of one-layer defect, external skin or intraoral lining, was carried out in 18 cases, through-and-through defect in 17 cases, and composite mandibular defect in two cases. With increasing knowledge of anatomy and refinements of surgical technique, the anterolateral thigh flap can be harvested safely to reconstruct complicated defects of head and neck following cancer ablation with only minimal donor-site morbidity.     

健侧C7 神经移位经椎体前通路的解剖学研究及经颈椎后入路 解剖学探讨

目的:为临床上开展健侧C7神经移位经椎体前通路治疗臂丛损伤提供解剖学基础。方法:选取10具20侧正常成人尸体颈段标本,将双侧臂丛充分显露,远端向C7神经根前后股进行干支分离,在前后股加入外侧束及后束前将其切断,近端向椎间孔处游离,测量C7神经根从椎间孔至分股处的长度及C7神经至前后股长度,测量并记录C7神经根及前后股经椎体前通路、颈前皮下通路到对侧臂丛上、下干的距离。结果:C7神经根的长度(58.62±8.70)mm,C7神经前、后股的长度(70.03±10.79)mm,(65.15±9.11)mm,C7神经根经颈前皮下、椎体前通路至对侧上下干的缺损长度分别是(98.18±10.18)mm,(107.14±9.88)mm;(32.10±11.49)mm,(37.28±10.01)mm两组相比有统计学差异。结论:从解剖学角度而言,健侧C7神经移位经椎体前通路能明显缩短移植神经长度,在临床上具有可操作性。     

Larval head anatomy of Heterogynis penella (Zygaenoidea, Heterogynidae), and a general discussion of caterpillar head structure (Insecta, Lepidoptera)

The internal head anatomy (and the peculiar integumental structure of the epicranial notch region) of Heterogynis penella larvae are described; special attention is paid to the skeleto‐muscular and nervous systems and to the cephalic glands. Transverse ligaments connect the apodemes of the mandibular adductor muscles of both sides and the anterior maxillo‐labial articulations of both sides. The two ligaments are linked to each other by a thin, apparently acellular membrane. An accessory, trilobed mandibular gland is present. A putative stretch receptor, connecting the oblique dorsal cibarial dilators of both sides, is described for the first time in a lepidopterous larva and its importance in assessing the homology of these muscles is discussed. The presence of cibarial sensilla, previously predicted in other caterpillars on the basis of behavioural experiments and observations of the nerve pattern, is confirmed. The structural diversity of larval head anatomy in ditrysian Lepidoptera is discussed, with particular emphasis on the innervation of the corpora cardiaca and corpora allata and of the sensilla of the head capsule.     

Extended lower trapezius island myocutaneous flap: a fasciomyocutaneous flap based on the dorsal scapular artery

The lower trapezius island myocutaneous flap is a useful flap in head and neck reconstruction. It is thin and pliable and can reach defects in most areas of the head and neck. Its usefulness in head and neck reconstruction has often been limited or discouraged by reports of significant failure rates. In this study, the vascular anatomy and clinical use of the extended lower trapezius myocutaneous flap based solely on the dorsal scapular artery system are elucidated, and experience gained performing 20 flaps over the past 5 years by using the extended lower trapezius myocutaneous flap is reported. The vascular anatomy of the dorsal scapular artery system is reviewed in 13 fresh cadaveric dissections by using methylene blue, latex injection studies, and radiologic examination.     

The nerve supply to the clavicular part of the pectoralis major muscle: an anatomical study and clinical application of the function-preserving pectoralis major island flap

The purpose of this study was to investigate the nerve supply to the clavicular part of the pectoralis major muscle so that the innervation to this part can be maintained in the muscle-preserving pectoralis major island-flap transfer. Although methods have been described that include a limited portion of the muscle while leaving the upper parts undisturbed with an intact motor innervation, reports on anatomical studies of this nerve supply are brief. The distal distribution of the nerves, the spatial relationship to the main vascular pedicle, and the ways to preserve them during surgical procedures remain unclear. Surgically relevant features of the clavicular part of the pectoralis major muscle were studied by dissection. The nerve supply to this part was examined on 11 sides of eight formalin-fixed cadavers. Two fresh cadavers were used for dissection, intraarterial polymer injection, and application of a nerve-preserving surgical technique. In all subjects, a separate nerve innervated the clavicular and upper medial sternocostal portions of the pectoralis major muscle. This nerve arises craniomedial to the main vascular pedicle of the flap and divides into several branches. These branches run in a fascia on the deep surface of the pectoralis major muscle, superficial to the origin and distal course of the vascular pedicle. Most branches to the clavicular part end medial to the coracoid process. The course of the branches to the upper sternocostal part is more medial. Based on their anatomical findings, the authors propose a surgical technique for transfer of the pectoralis major island flap to the head and neck area through a tunnel in the deltopectoral groove, lateral to the origin of the vascular pedicle. Head and neck reconstruction was performed using this technique. The presented method is a muscle-preserving procedure that maintains maximal donor-site function and morphology.     

Neurovascularized free short head of the biceps femoris muscle transfer for one-stage reanimation of facial paralysis

The single-stage technique for cross-face reanimation of the paralyzed face without nerve graft is an improvement over the two-stage procedure because it results in early reinnervation of the transferred muscle and shortens the period of rehabilitation. On the basis of an anatomic investigation, the short head of the biceps femoris muscle with attached lateral intermuscular septum of the thigh was identified as a new candidate for microneurovascular free muscle transfer. The authors performed one-stage transfer of the short head of the biceps femoris muscle with a long motor nerve for reanimation of established facial paralysis in seven patients. The dominant nutrient vessels of the short head were the profunda perforators (second or third) in six patients and the direct branches from the popliteal vessels in one patient. The recipient vessels were the facial vessels in all cases. The length of the motor nerve of the short head ranged from 10 to 16 cm, and it was sutured directly to several zygomatic and buccal branches of the contralateral facial nerve in six patients. One patient required an interpositional nerve graft of 3 cm to reach the suitable facial nerve branches on the intact side. The period required for initial voluntary movement of the transferred muscles ranged from 4 to 10 months after the procedures. The period of postoperative follow-up ranged from 5 to 42 months. Transfer of the vascularized innervated short head of the biceps femoris muscle is thought to be an alternative for one-stage reconstruction of the paralyzed face because of the reliable vascular anatomy of the muscle and because it allows two teams to operate together without the need to reposition the patient. The nerve to the short head of the biceps femoris enters the side opposite the vascular pedicle of the muscle belly, and this unique relationship between the vascular pedicle and the motor nerve is anatomically suitable for one-stage reconstruction of the paralyzed face. As much as to 16 cm of the nerve can be harvested, and the nerve is long enough to reach the contralateral intact facial nerve in almost all cases. The lateral intermuscular septum, which is attached to the short head, provides "anchor/suture-bearing" tissue, allowing reliable fixations to the zygoma and the upper and lower lips to be achieved. In addition, the scar and deformity of the donor site are acceptable, and loss of this muscle does not result in donor-site dysfunction.     

Digital volume tomography in the diagnosis of the surgical anatomy of the frontal recess area

Frontal recess anatomy can be very complex, with accessory cells, such as frontal bulla, agger nasi, suprabulla, and frontal ethmoidal (Kuhn) cells, which may lead to obstruction of the frontal sinus. Digital volume tomography of paranasal sinuses used in this investigation revealed the rate of types of development of various anatomic structures and their correlation with frontal sinusitis in patients with (a study) and without the latter (a control group).     

Suboesophageal neurons involved in head movements and feeding in locusts.

The projections of nerves 6 and 7 of the locust suboesophageal ganglion (SOG) were stained by axonal filling with cobalt chloride. Nerve 6 contains two motoneurons which innervate neck muscles 50 and 51. Sensory neurons innervating hairs on the dorso-occipital region of the head also enter the ganglion through nerve 6 and terminate in a small bilateral plexus. The projections of the head hairs in nerve 6 do not overlap the arborizations of the motoneurons or the neurons of nerve 7, but lie in the same area as descending sensory neurons from wind-sensitive hairs of the front of the head. One branch of nerve 7 (7B) contains two fibres which innervate the salivary gland. These 'salivary' neurons (labelled SN1 and SN2) have their cell bodies in the ganglion. The second branch, 7A, contains sensory neurons from the submentum of the labium, which form four sensory plexuses, two dorsal and two ventral. The sensory plexuses from the submentum have specific regions of overlap with the salivary neurons and with the neck muscle motoneurons. We interpret these as indicating a flow of information from labial receptors signalling head and mouthpart movement to neurons involved in salivation and head movement. We further postulate that the anatomical separation of the various sensory plexuses is indicative of functional localization within the ganglion.     

Isolation and characterization of axolemma-enriched fractions from rabbit and bovine peripheral nerve

Axolemma-enriched fractions were isolated from bovine spinal accessory nerves, bovine intradural dorsal roots, and rabbit sciatic nerve by differential centrifugation and separation on a linear 10–40% sucrose (w/w) gradient. The fractions were enriched 4 to 10 fold in acetylcholinesterase, a biochemical marker for axolemma. Axolemma-enriched fractions isolated from uniformly well-myelinated fibers (bovine spinal accessory nerve) contained lower CNPase activity and higher acetylcholinesterase activity than comparable fractions isolated from variably myelinated fibers (rabbit sciatic nerve and bovine intradural roots). Separation by polyacrylamide electrophoresis showed that the molecular weight distribution of all peripheral nerve axolemma-enriched fractions was similar and ranged from 20 to over 150 kilodaltons. All axolemma-enriched fractions appeared to contain a small but variable amount of myelin-specific proteins. Based on biochemical properties, peripheral nerves containing uniformly well-myelinated fibers yield an axolemma-enriched fraction which is least contaminated with myelin-related membranes.     

Incidence of early posterior shoulder dislocation in brachial plexus birth palsy

Background

Nerve transfers are commonly employed in the treatment of brachial plexus injuries. We report the use of a new donor for transfer, the platysma motor branch.

Methods

A patient with complete avulsion of the brachial plexus and phrenic nerve paralysis had the suprascapular nerve neurotized by the accessory nerve, half of the hypoglossal nerve transferred to the musculocutaneous nerve, and the platysma motor branch connected to the medial pectoral nerve.

Results

The diameter of both the platysma motor branch and the medial pectoral nerve was around 2 mm. Eight years after surgery, the patient recovered 45° of abduction. Elbow flexion and shoulder adduction were rated as M4, according to the BMC. There was no deficit after the use of the above-mentioned nerves for transfer. Volitional control was acquired for independent function of elbow flexion and shoulder adduction.

Conclusion

The use of the platysma motor branch seems promising. This nerve is expendable; its section led to no deficits, and the relearning of motor control was not complicated. Further anatomical and clinical studies would help to clarify and confirm the usefulness of the platysma motor branch as a donor for nerve transfer.