Aberrant axillary artery descending deep beneath the brachial plexus

An aberrant axillary artery that descended deep beneath the brachial plexus during its course was observed. The artery passed between the lateral and medial cords, as would an ordinary axillary artery, but further passed between the posterior divisions forming the posterior cord. The axillary artery turned medially to emerge from the lower border of the medial cord and finally ran as an ordinary artery. The aberrant axillary artery is judged to reach deeper to the brachial plexus, because it penetrated the posterior division of the brachial plexus from superficial to deep. It is possible to account for the formation of this artery as one of the combinations of the ordinary axillary artery and its branches, with the positional relationships between the brachial plexus.     

The axillary sheath and single-injection axillary block

Failure to block the terminal nerves of the brachial plexus, the circumferential type of incomplete axillary brachial plexus block, is the main problem of the single-injection technique. Two studies were carried out to observe the internal anatomy of the axillary sheath and the effect of different volumes of dye injected into the sheath in cadavers. In our first study, the internal arrangement of the axillary sheath and its septae were examined microscopically by slicing the sheath longitudinally and transversely. In the second study, boluses of 10, 20, and 40 cc of methylene-blue were injected into one of the compartments of the axillary sheath. The axillary sheath was dissected out and sliced transversely to observe the spread of the dye in the injected and in the adjacent compartments. The specimens of the axillary sheath were then opened longitudinally and the septae excised and examined at x10 magnification to see the effect of the various volumes of the injection bolus. This study shows that septae from the deep surface of the axillary sheath form compartments for each nerve. The septae function as barriers under physiologic conditions. By increasing the injected volume of solutions, bubble-like defects are produced in the septae in the compartments into which leakage was demonstrated.     

Nerve fiber analysis on the so-called accessory subscapularis muscle and its morphological significance

A rare muscular anomaly, so-called accessory subscapularis muscle, was found in the left axillary fossa of a 95-year-old male cadaver during a student dissection practise. The muscle arose near the lateral margin of the scapula from the surface of the subscapularis muscle and ran upward to fuse with the capsule of the shoulder joint via a tendon. It measured 1.0 cm in width, 7.0 cm in length and 1.5 mm in thickness, and was separated from the underlying subscapularis muscle by the axillary and inferior subscapular nerves. Macroscopically, the anomalous muscle received its nerve supply from a branch arising from the lower root of the radial nerve near the origin of the thoracodorsal nerve and entered the muscle from its ventral surface. Nerve fiber analysis showed that the supplying nerve originated from fibers of the dorsal element of C7 immediately cranial to the thoracodorsal nerve. These findings indicate that the present anomalous muscle might be close to the formation of the latissimus dorsi muscle in its derivation rather than the subscapularis muscle.     

超声平面外技术联合神经刺激器腋路动脉旁注药臂丛神经阻滞效果研究

目的 探讨超声平面外技术联合神经刺激器引导腋路动脉旁注药臂丛神经阻滞的效果。方法 选择2015年9月—2016年9月河北医科大学第三医院单侧肘关节下骨折择期行手术治疗的60例患者进行前瞻性研究。60例患者按随机数字表法分为观察组、对照组,每组30例。观察组采用超声平面外技术联合神经刺激器行腋路动脉旁注药臂丛神经阻滞,对照组采用超声平面内技术联合神经刺激器行腋路臂丛神经阻滞。观察比较两组患者麻醉操作时间、麻醉起效时间、感觉阻滞效果、运动阻滞效果、对止血带耐受情况、麻醉并发症发生情况及手术时间。结果 两组60例患者均顺利完成手术,术中无刺破血管、局麻药中毒等并发症发生。两组间比较,观察组麻醉操作时间(6.0±1.2)min,短于对照组的(11.5±2.1)min;麻醉起效时间(13.0±1.7)min,长于对照组的(7.8±1.5)min;运动完全阻滞率为53.3%(16/30),低于对照组的90.0%(27/30),差异均有统计学意义(t=12.464、-12.781,χ²=9.932,P值均﹤0.01);而两组感觉阻滞效果、止血带耐受、手术时间等差异均无统计学意义(P值均＞0.05)。结论 超声平面外技术联合神经刺激器腋路动脉旁注药臂丛神经阻滞麻醉操作简单、安全,效果确切,有很好的临床应用价值。     

Trifurcation of brachial artery with variant course of radial artery: Rare observation

Variations in the arterial pattern of the upper limb have been observed frequently, either in the routine dissections or in clinical practice. The aim of the present study was to describe the anatomical, surgical and embryological importance of major arteries of upper limbs of human beings. The present article is the report of low division and trifurcation of brachial artery and abnormal course of radial artery (passing deep to the pronator teres muscle) found in a 45-year-old embalmed male cadaver. Knowledge of the arterial variations in the upper limb is of considerable importance during invasive and non-invasive investigative procedures or orthopedic, reconstructive, or surgical procedures.     

Destination of the C4 component of the prefixed brachial plexus

This study was carried out to elucidate the destination of the C4 ventral ramus that forms the prefixed brachial plexus. A total of 43 sides of Korean adults (male, 22; female, 18; unknown: 3 and right, 23; left, 20) were investigated. The various C4 destinations and their frequencies were as follows: suprascapular nerve, 97.7% (42/43); musculocutaneous nerve, 79.1% (34/43); the axillary nerve, 48.8% (21/43); and the nerve to subclavius, 16.2% (7/43). The mean quantity of nerve fibers destined to the suprascapular, musculocutaneous, and axillary nerves and the nerve to subclavius was 441.8 ± 316.5 (Mean ± S.D.), 298.2 ± 209.8, 245.8 ± 239.0, and 66.4 ± 17.2, respectively. The mean nerve fibers number of C4 contributing to the brachial plexus was 983.6 ± 618.0 (range: 100-1729). The main component that contributes to the terminal nerves (suprascapular, musculocutaneous, axillary nerves, and nerve to subclavius) is C5. These results may be useful to surgeons and clinicians dealing with terminal nerves of the brachial plexus, especially the suprascapular, musculocutaneous, and axillary nerves.     

桡,尺动脉肌,皮支的解剖学研究

目的:为手外科提供桡、尺动脉分出的肌、皮支.材料和方法:用福尔马林常规固定的成尸上肢69(男61,女8)侧,解剖观测桡、尺动脉分支的部位、支数及外径.主要结果:从尺、桡动脉壁两侧发出分支,大部分为不对称性分支间距不等,平均(3.0～15.0)mm.桡动脉平均分出15.8支,其中肌支10.3支,筋膜皮支5.5支.尺动脉平均分出12.4支,其中肌支7.6支,筋膜皮支4.8支.结论:桡、尺动脉分出肌、皮支,皮支为前臂筋膜瓣、皮瓣的血管蒂.     

The lateral thoracic artery passing through duplicated axillary vein: A case report

The axillary vein is a large‐blood vessel that lies on the medial side to the axillary artery. The veins of the axilla are more abundant than the arteries and their variations were extremely common. During educational dissection, a rare form of the axillary vein accompanying arterial variation was founded in left arm of 70‐year‐old female cadaver. The axillary vein was divided into two large veins, anterior and posterior axillary veins according to their anatomical position. The lateral‐thoracic artery arose from the second part of the axillary artery and passed through the gap of duplicated axillary vein. Before the lateral‐thoracic artery passed through the gap of duplicated axillary vein, the lateral‐thoracic artery gave‐off an additional branch, which descended superficial to the anterior axillary vein. It surrounded the anterior axillary vein as annular form and the diameter of surrounded part of the anterior axillary vein became narrow. This novel case was reported and its clinical implications of such a variant were discussed. Clin. Anat. 26:1014–1016, 2013. © 2012 Wiley Periodicals, Inc.     

腋动脉及其分支的应用解剖学研究

目的探索国人腋动脉(AA)及其分支的类型、量化数据以及他们之间的比例关系。方法解剖观察32具成人尸体标本(男25具、女7具)的腋动脉分支类型、外径及腋动脉起始段的外径与其自身比例,腋动脉3段的长度、外径,计算三者间的自身比例。结果腋动脉分支分为7型及1个变异型。每型又分为若干亚型,以6支型(出现率30.16%)和5支型(出现率26.98%)多见;腋动脉3段长度差异较大,三者之比为1∶1.18∶1.25,外径由第一段至第三段渐细,三者之比为1∶0.89∶0.75,腋动脉的各分支依据其支数及起始位置的不同,分为若干型及亚型。腋动脉起始端与各分支起始端外径之比分别为胸上动脉(TS)1∶0.28,胸肩峰动脉(TA)1∶0.42,胸外侧动脉(TL)1∶0.31,肩胛下动脉(SS)1∶0.63,旋肱前动脉(CHA)1∶0.25,旋肱后动脉(CHP)1∶0.46。结论腋动脉及其分支的变异较大,临床介入放射学及血管外科学对血管处理或选择时,应以出现率高、类型恒定、管径允许者作为应用对象。     

Superficial ulnar artery terminating in a normal ulnar artery

Routine dissection of the left upper limb of an 86-year-old male cadaver showed a superficial ulnar artery that anastomosed with the ulnar artery. The superficial ulnar artery arose from the third part of the axillary artery, coursed distally over the flexor muscles of the forearm, and terminated by anastomosing with the ulnar artery in the distal third of the forearm. Arterial and neural variations were also observed on the contralateral side. The presence of a superficial ulnar artery is important clinically when raising forearm flaps in reconstructive surgery.     

Anatomical Study of the Brachial Plexus in the Common Marmoset (Callithrix Jacchus)

To elucidate the forelimb phylogeny of primates, anatomical analysis of the brachial plexus in platyrrhines is beneficial. In the present study, six brachial plexuses and the surrounding arteries of four common marmosets were dissected. In five specimens, the brachial plexus consisted of five ventral rami from the fifth cervical nerve (C5) to the first thoracic nerve (T1). In one specimen, the ventral ramus of the fourth cervical nerve joined with the brachial plexus. In five specimens, the upper trunk was composed of C5 and the sixth cervical nerve (C6). In one specimen, the ventral division of C6 merged with the ventral branch of the middle trunk to constitute the lateral cord. The seventh cervical nerve constituted the middle trunk, and the eighth cervical nerve and T1 formed the lower trunk in all specimens. The lateral cord gave rise to the musculocutaneous nerve, and the remaining component merged with the medial cord. The confluence of the lateral and medial cords immediately bifurcated into the median and ulnar nerves. These branching patterns of the musculocutaneous, median, and ulnar nerves were consistent and similar to the human counterparts. In the dorsal division, the single posterior cord as observed in the human brachial plexus was not observed. The axillary artery did not pass between the medial and lateral roots of the median nerve, and the axillary artery bifurcated into the brachial artery and the superficial brachial artery. Anat Rec, 300:1299–1306, 2017. © 2017 Wiley Periodicals, Inc.     

The spinal root origins and clinical implications of the lower subscapular nerve

The purpose of this study was to define the spinal root origins of the lower subscapular nerve and the amounts of participating nerve fibers from each spinal root and to discuss the clinical implications. Using a method of separating the nerve fascicles that traces the particular nerve fibers at the intrafascicular level, the spinal root origins of the lower subscapular nerve appeared as two types. The first type comprised 76.9% and was composed of the C5, C6, and C7 roots; the second type comprised 23.1% and was composed of the C6 and C7 roots. The number of nerve fibers was 357.2 +/- 139.7 (mean +/- SD) derived from C5, 1070.4 +/- 390.6 from C6, and 500.0 +/- 285.4 from C7. The nerve fascicles comprising the lower subscapular nerve traveled within the partially common fascicles composed of the axillary nerve. Therefore, injury of the lower subscapular nerve may be accompanied by a lesion of the axillary nerve, which generally consists of C5 and C6 roots composing the posterior cord of the brachial plexus.     

Radial artery running beneath the biceps tendon and its interrelation between the radial recurrent arteries

A radial artery running beneath the biceps tendon was found in the cadaver of a Japanese woman during a student dissection course at Kumamoto University School of Medicine in 2006. The brachial artery bifurcated into the radial artery and the ulnar artery in the cubital fossa, and the radial artery twisted laterally running beneath the biceps tendon, and when it was situated laterally to the tendon, twisted distally at the level of the radial tuberosity, and then twisted medially again. After the radial artery passed over the biceps tendon, it turned distally and continued as a normal radial artery. The superficial brachial artery, which coexisted with the brachial artery, was given off from the axillary artery and it continued to the final twist of the radial artery. The course of this radial artery is similar to the arterial rings surrounding the biceps tendon, found during the same dissection course. The arterial rings were formed between the brachial artery and the radial artery, and their proximal origins ran beneath the biceps tendon, while the distal origins were superficial. The present arterial variation is thought to have occurred when the normal part of the radial artery in the cubital fossa was substituted by the arterial ring, coexisting with the superficial brachial artery, which usually disappears during normal development. Furthermore, it is suggested that a part of the arterial ring always remains as a radial recurrent artery.     

尺神经中第七颈神经成份的行径及临床意义

用神经束追踪分离法解剖观察100侧成人第七颈神经分布至尺神经内的纤维行径。结合临床观察认为,尺神经内部有来自颈七的纤维,主要经4个交通部位加入到尺神经分布区内。证明脊神经相应节段与骨骼肌或肌群的支配关系是恒定的,只是由于在胚胎发生上臂丛组合的不同,使脊神经的分支到所支配的骨骼肌间的行径出现差异。上述研究结果,对臂丛中、下干损伤准确定位诊断有重要意义。     

“Triceps Brachii Muscle Response to Neurostimulation of the Radial Nerve during Axillary Plexus Blockade: Clinical,Anatomical and Histological Correlation”

Axillary plexus blockade is a common technique in clinical practice with a well-known pattern of structures around the brachial artery. Historically, the only proper response to radial nerve stimulation was considered to be extension of the hand and wrist. Twenty-five axillary blockades were assessed by ultrasound and neurostimulation; the principal objective was to correlate the needle position over the radial nerve with the anatomical and histological structure of that nerve. During the procedure, the needle was directed in two ways to reach the medial or lateral margin of the nerve: above the brachial artery or beneath it. Once the needle reached the nerve, the current was augmented gradually until a response was elicited. For the cadaveric anatomical study, eight axillae were dissected and histological samples were examined. The response of the triceps brachii muscle differed significantly between the two approaches to the radial nerve (P < 0.001), and the mean intensity of stimulation was significantly lower when the nerve was accessed above the artery (0.44 ± 0.15 mA) than below it (0.57 ± 0.17 mA) (P = 0.015). A triceps brachii motor response occurs at lower current intensity and lower needle-nerve distance when the radial nerve is accessed above the artery and over the latissimus dorsi tendon. These findings were correlated with the topography of the radial nerve in the axillary fossa. Clin. Anat. 33:578–584, 2020. © 2019 Wiley Periodicals, Inc.