[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Upper limb](https://durgical.com/en/anatomy/region/upper-limb/) › Lateral thoracic artery [Cardiovascular system](https://durgical.com/en/anatomy/system/cardiovascular-system/) · [Upper limb](https://durgical.com/en/anatomy/region/upper-limb/) # Lateral thoracic artery The lateral thoracic artery runs down the side of the chest wall from the armpit; it supplies the outer part of the breast. [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=upper_limb&select=lateral_thoracic_artery&side=r) Opens in the Durgical app, no sign-up needed. ## What it is A branch of the second part of the axillary artery that runs down the side of the chest along the lower edge of pectoralis minor. ## What it does Supplies serratus anterior, the pectoral muscles, the axillary nodes and the outer part of the breast. ## Key points - Main supply of the lateral breast, second in importance after the [internal thoracic artery](https://durgical.com/en/anatomy/internal-thoracic-artery/); its mammary branches enlarge in lactation - Runs down the chest wall on the serratus anterior close to the long thoracic nerve, which can be injured with it in axillary surgery - Origin is variable: from the second part of the axillary artery, or from the thoracoacromial or subscapular artery ## Key facts **Origin** Second part of axillary artery (behind pectoralis minor) **Branches** Lateral mammary branches; branches to serratus anterior and pectoral muscles **Supplies** Lateral breast, serratus anterior, pectoral muscles; runs along the lower border of pectoralis minor ## Relations **Course** Leaves the [axillary artery](https://durgical.com/en/anatomy/axillary-artery/) behind the [pectoralis minor](https://durgical.com/en/anatomy/pectoralis-minor-muscle/) and descends along its lower border onto the side of the [chest](https://durgical.com/en/anatomy/region/chest/) wall **Deep** [Serratus anterior](https://durgical.com/en/anatomy/serratus-anterior/), with the [long thoracic nerve](https://durgical.com/en/anatomy/long-thoracic-nerve/) on its surface further back in the midaxillary line **Superficial** Axillary tail of the breast and the pectoral group of the axillary lymph nodes **Behind** [Thoracodorsal nerve](https://durgical.com/en/anatomy/thoracodorsal-nerve/) and vessels on the posterior axillary wall ## How to find it Not palpable. In axillary dissection it is seen running down the lateral border of the pectoralis minor onto the serratus anterior; handheld Doppler can map its [skin](https://durgical.com/en/anatomy/skin/) branches before flap surgery. ## On imaging CT or MR angiography shows it running down the chest wall on the serratus anterior, along the lateral border of the pectoralis minor. It is not singled out on mammography, but on contrast breast MRI its branches appear as vessels entering the upper outer breast. Before flap surgery, CT angiography or handheld Doppler maps it. ## Common problems - Enlarges to feed the breast; tied or sealed during axillary and breast surgery. ## Clinical notes - Often divided in axillary dissection; the long thoracic nerve nearby must be kept, as its injury causes winging of the [scapula](https://durgical.com/en/anatomy/scapula/) - Breast reduction and lift operations plan their tissue pedicles to keep enough of its supply to the [nipple](https://durgical.com/en/anatomy/nipple/) and [areola](https://durgical.com/en/anatomy/areola/) - Its perforators can carry a flap of lateral chest skin and fat to fill defects after partial mastectomy - In the male breast its lateral mammary branches are small, but it is met in surgery for gynaecomastia and male breast cancer ## Anatomical variants - Arises from the [thoracoacromial artery](https://durgical.com/en/anatomy/thoracoacromial-artery/), the subscapular artery or a common trunk in a sizeable minority; it may be small and replaced by branches of the subscapular artery ## Test yourself Think of the answer, then tap the question to see it. ## What does the lateral thoracic artery supply in the breast? The lateral breast; it is the second main supply after the internal thoracic artery, and its branches enlarge in lactation. ## Which nerve runs close to the lateral thoracic artery, and what does its injury cause? The long thoracic nerve on serratus anterior; injury causes winging of the scapula. ## From where does the lateral thoracic artery usually arise? The second part of the axillary artery, behind pectoralis minor; it can also arise from the thoracoacromial or subscapular artery. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/anatomy/lateral-thoracic-artery/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** arteria thoracica lateralis TA2 4625 **Official Spanish (DeCS)** Arteria torácica lateral **English (TA2)** Lateral thoracic artery **Also called** external mammary artery ## Related - [Anterior axillary nodes](https://durgical.com/en/anatomy/anterior-axillary-nodes/) - [Lateral thoracic vein](https://durgical.com/en/anatomy/lateral-thoracic-vein/) - [Serratus anterior](https://durgical.com/en/anatomy/serratus-anterior/) - [Long thoracic nerve](https://durgical.com/en/anatomy/long-thoracic-nerve/) - [Pectoralis major](https://durgical.com/en/anatomy/pectoralis-major-muscle/) - [Pectoralis minor](https://durgical.com/en/anatomy/pectoralis-minor-muscle/) Sources: Terminologia Anatomica (TA2); [Anatomy, Thorax, Breast](https://www.ncbi.nlm.nih.gov/books/NBK519575/); [Anatomy, Shoulder and Upper Limb, Axilla](https://www.ncbi.nlm.nih.gov/books/NBK547723/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/lateral-thoracic-artery/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/lateral-thoracic-artery/