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

Abstract

We investigated the ramification patterns of four subclavian branches (i.e., vertebral artery, internal thoracic artery, thyrocervical trunk, and costocervical trunk) as the subclavian artery passes in front or behind the scalenus anterior muscle. The investigation was carried out on 56 cadavers (112 cases) during student dissection practice sessions at Osaka Dental University. In 110 of the 112 cases, the subclavian artery passed behind the scalenus anterior muscle. The pattern of ramification of the subclavian branches in these cases was classified into six types (types A-F). In the remaining two cases (two cadavers), the subclavian artery passed in front of the scalenus anterior muscle. In both of these latter cases, the pattern of ramification of the subclavian branches differed from the six pattern types observed as the subclavian artery passed behind the scalenus anterior muscle: the first branch was the vertebral artery; the second, the costocervical trunk; the third, the thyrocervical trunk; the fourth, the internal thoracic artery. This same pattern of ramification was observed in three previously reported cases (two cadavers) in which the subclavian artery passed in front of the scalenus anterior muscle. Taken together, these observations indicate that the ramification pattern reported here and in a previous investigation for the subclavian artery passing in front of the scalenus anterior muscle is characteristic of this anatomical condition.

A study on origin, termination, and course characteristics of internal thoracic artery relevant to coronary surgeries and reconstructive procedures

“…This incidence of 100% was compared with previous studies as shown in Table 3 . Other abnormal origins as observed by Daseler and Anson [ 12 ], Henriquez-Pino et al [ 13 ], Vorster et al [ 14 ], Uemura et al [ 15 ], and Karaman et al [ 5 ] were not observed in our study.…”

Scalenus Minimus Muscle: Overestimated or Not? An Anatomical Study

“…3,7,9 Variations in the course and branching of the subclavian artery have been reported to accompany the presence of SMM. 10,11 However, in our series, the subclavian artery had a typical course behind the anterior scalene muscle and in front of the SMM. It passed over the superior surface of the first rib and its branching followed the typical anatomical pattern.…”

Scalenus Anterior Muscle With Two Heads Associated With Variation in the Branches of Subclavian Artery: a Rare Presentation

“…Nidhi Puri et al reported in their study that a common trunk gives rise to ITA with other branches of subclavian artery in 12% on right side and 4% on left side [7]. A study on pattern of ramification of the subclavian artery in 56 cadavers (112 sides) reported that subclavian artery lying in front of the scalenus anterior muscle (3.5%) and also stated that the ITA originated from the TCT in 11.8 % of cases [8]. Lischka et al [9] mentioned in their study that the left ITA originated from the TCT in 10% of his cases, while the right ITA had the similar origin only in 2 %.…”