Study on the Subclavian Artery and its Branches in Japanese Adults

Abstract

Summary: We examined the entire array of branches and the state of ramification of each branch of 144 subclavian arteries (Su) in 72 Japanese adults, and obtained the following findings.(1) The incidence of Type I -A(1) was 13.2%, the highest among the entire Su ramification. This was followed by Type I -B(1) at 9.0%, then Type I -A(2) at 6.9%, indicating considerable variation in the morphology of Su ramification. (2) Ontogenetic factors were implicated because of the existence of cases in which Su traversed the scalenus anterior muscle anteriorly (Type III : 0.7%), or was transfixed (0.7%). (3) Type 1-c was the form of thyrocervical trunk (Tic) observed with the highest incidence of 31.3%. In addition, inferior thyroid artery, and those in which another branch was included in this common trunk: 88.9%) be called Ttc.(4) The most common type of transverse cervical artery (Tc), which is formed from a common trunk consisting of highest incidence of 61.8%. Some of the superficial branches to the upper portion of the trapezius muscle that were independently from Su. We concluded that the sites at which Tc and Ss originate are the positions at which they traverse the brachial plexus (superior, transfixed to the plexus). (6) In cases in which the supreme intercostal artery (Is) and the deep cervical artery (Cp) were separate, (Types d-i excluding Type g: 31.9%), Is branched from a more proximal position than Cp.Formation of the human subclavian artery to an almost adult condition occurs in about 7 weeks of embryonic development.5, 6, 10, 26) There have been numerous reports of substantial individual and racial differences in the position of arterial branches and the nature of their ramifications as a result of various factors that have an influence on morphosis.7, 12, 13, 17, 21, 27, 29, 33, 35, 44) However, there are almost no reports of studies that have attempted to characterize and classify the ramification and positions of the entire array of branches arising from the subclavian artery. The only relevant reports in Japan were those by Adachi (28)1) and Ouchi ('63)3°), who described the subclavian artery ramification in Japanese adults, and that by Mori (P41)28), who described Japanese fetuses. However, these reports did not explain the entire subclavian artery ramification, nor determined the most common type of ramification or its incidence among the Japanese population.With recent increase in the use of CT, MRI and angiography, it has been pointed out that an accurate understanding of the morphology of the normal subclavian artery32) and detailed information about the ramification and course of arteries that branch from the subclavian artery12. 22) are essential prerequisites for accurate diagnosis by these techniques of pathogenic changes in the upper limbs. Furthermore, sternocleidomastoid muscle and trapezius muscle are frequently used as a musculocutaneous flap in reconstructive surgery, but despite the fact that the nutrient artery which supplies these muscles is a branch of the subclavian artery, reports ...

Anatomical study of the vertebral artery in Japanese adults

“…The results were Adachi (1928) 94.6% (488) 5.4% (28) 516 Aso (1932) 96.8% (61) 3.2% (2) 63 Mori (1941) 93.1% (54) 6.9% (4) 58 Takafuji and Sato (1991) 93.1% (67) 6.9% ( Adachi (1928) on the Japanese and the data of Miyashita (1935) on the Chinese (Table 4). In the present study, the distance between the origin of the right vertebral artery and the branching point in the brachiocephalic trunk was 0 -5 mm in six of 345 bodies (1.7%), 11-25 mm in 219 bodies (63.5%) and 72 mm (the longest) in one body.…”

Comparative study of the ramification patterns of the subclavian branches as the subclavian artery passes in front or behind the scalenus anterior muscle

“…However, Uemura et al (2007) were able to observe the scalenus anterior, medius, posterior, and minimus muscles in the right side in their cases. They therefore concluded that the hypothesis of Takafuji and Sato (1991) was not applicable to this anatomical situation. Komatsu et al (1984) and Yuda et al (2000) suggested that the passage of the subclavian artery in front of the scalenus anterior muscle is caused by a dorsal shift of the region to which the scalenus anterior muscle is inserted.…”

“…Takafuji and Sato (1991) suggested that the mechanism of the abnormality was caused by the disappearance of the primordium of the scalenus anterior muscle and the remaining portion of the primordium of the scalenus minimus muscle, resulting in the subclavian artery passing in front of the scalenus muscle (developing scalenus minimus muscle). However, Uemura et al (2007) were able to observe the scalenus anterior, medius, posterior, and minimus muscles in the right side in their cases.…”

Bilateral anatomic variation in the relation of the upper trunk of the brachial plexus to the anterior scalene muscle

“…Milliez i Sakka [13] state that the ASM and the MSM develop from a common premuscle mass, which is later penetrated by the BP and the SA [13]. Takafuji and Sato [21] suggest that the original ASM has divergent fibres -anterior and posterior to the SA -with the latter fibres receding during the development of the neck. The authors hypothesize that the persistence of the posterior fibres may affect the relation of the ASM to the BP [21].…”

“…Takafuji and Sato [21] suggest that the original ASM has divergent fibres -anterior and posterior to the SA -with the latter fibres receding during the development of the neck. The authors hypothesize that the persistence of the posterior fibres may affect the relation of the ASM to the BP [21]. The interaction of the neural primordium to the premuscle mass [15] and the blood vessels [2] is considered as the key factor in the development of the anatomical variations of the neck and the axilla.…”