PMC8616708_01
Graphic representation of variations of arterial branching pattern of the posterior thoracic wall, as seen in an 81-year-old cadaver: (a) right highest intercostal artery, supplying only 1st ICS; (b) right descending branch of vertebral artery, supplying 1st-3rd ICS; (c) left highest intercostal artery, following typical anatomical arterial supply; (d) right superior common trunk, giving off 4th-7th PIAs; (e) right 8th PIA, directly from the TA; (f) right 9th PIA, with diminished size directly from TA; (g) right inferior common trunk, giving of 9th-11th PIAs; (h) left superior common trunk, giving off 3rd-5th PIAs; (i) left middle common trunk, giving off 6th-7th PIAs; (j) left 8th, 9th, and 10th PIAs, directly from the TA; (k) left inferior common trunk, giving off 11th PIA and subcostal artery.
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fig2
Multiple arterial variations in the posterior thoracic region were noted during routine dissection (Figure 2). TA, along with 2 typical PIAs. The right superior CT arose from the TA between the 7th and 8th thoracic vertebrae (Figures 2(d) and 3(b)). TA at the level between the 10th and 11th thoracic vertebrae (Figures 2(g) and 3(c)). These 3 PIAs also appeared to take on a more tortuous appearance than is typically seen. The 8th and 9th PIAs originated from the TA in the typical fashion and traveled to the respective ICS (Figures 2(e) and 2(f)). TA between the 6th and 7th thoracic vertebrae where it then coursed superiorly to supply the 5th, 4th, and 3rd ICS (Figures 2(h) and 4(a)). The middle CT originated from the TA between the 7th and 8th thoracic vertebrae before supplying the 7th and 6th ICS superiorly (Figures 2(i) and 4(b)). The left inferior CT arose from the TA between the 12th thoracic vertebra and the 1st lumbar vertebra before splitting into the 11th PIA and the subcostal artery (Figures 2(k) and 4(c)). The 8th, 9th, and 10th ICS were supplied by typical PIAs arising directly from the TA (Figures 2(j) and 5). The 1st and 2nd ICS were supplied by the highest intercostal artery, as is normally described above (Figures 2(c) and 4). A descending branch of the vertebral artery (DBVA) was found traveling inferiorly and dorsally near the first three ribs, through the costotransverse foramina (Figures 2(b), 3(a), and 5(a)). The highest intercostal artery was still present on the right side; however, it only supplied the 1st ICS, providing dual supply to this space (Figures 2(a) and 3). The left side of 1st and 2nd ICS was supplied by the left highest intercostal artery as normally seen (Figures 2(c) and 6).
Right posterior thoracic wall with exposed intercostal spaces: (a) the descending branch of the vertebral artery supplying the 1st-3rd ICS; (b) superior common trunk arising from TA between7th and 8th thoracic vertebrae supplying 4th-7th ICS; (c) inferior common trunk arising from TA between 10th and 11th thoracic vertebrae supplying 9th-11th ICS. Numbers 1-11: ICS number; 12: subcostal space; HICA: highest intercostal artery; DBVA: descending branch of the vertebral artery; Sup. CT: superior common trunk; TA: thoracic aorta; Inf. CT: inferior common trunk; N: nerve; V: vein; A: artery.
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fig3
A descending branch of the vertebral artery (DBVA) was found traveling inferiorly and dorsally near the first three ribs, through the costotransverse foramina (Figures 2(b), 3(a), and 5(a)). There was an irregular relationship in the neurovascular bundle of the 6th ICS on the right side (Figure 3).
Left posterior thoracic wall with exposed ICS: (a) superior common trunk arising from TA between 6th and 7th thoracic vertebrae supplying 3rd-5th ICS; (b) middle common trunk arising from TA between 7th and 8th thoracic vertebral level supplying 6th-7th ICS; (c) inferior common trunk arising from TA between 12th thoracic and 1st lumbar vertebrae supplying 11th ICS and subcostal space. Numbers 1-11: ICS number; 12: subcostal space; HICA: highest intercostal artery; 1st CT: first (superior) common trunk; 2nd CT: second (middle) common trunk; 3rd CT: third (inferior) common trunk; TA: thoracic aorta.
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fig4
Additional variations were seen in the neurovascular bundle relationships of the left side in the 2nd (nerve, artery, vein), 3rd (artery, vein, nerve), and 6th (nerve, vein, artery) ICS (Figures 4 and 6).
Left superior posterior thoracic wall showing neurovascular relationship in 2nd and 3rd ICS. The order of neurovascular bundle at the 2nd ICS (nerve, artery, vein) and 3rd ICS (artery, vein, nerve) from superior to inferior. Numbers 1-5: ICS number; HICA: highest intercostal artery; 1st CT: first common trunk; N: nerve; V: vein; A: artery.
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fig6
Additional variations were seen in the neurovascular bundle relationships of the left side in the 2nd (nerve, artery, vein), 3rd (artery, vein, nerve), and 6th (nerve, vein, artery) ICS (Figures 4 and 6).