Accessory hemiazygos vein
Updates to Article Attributes
The accessory (or superior) hemiazygos vein forms part of the azygos system and along with the hemiazygos vein, it is partially analogous to the right-sided azygos vein. It drains the left superior hemithorax.
Terminology
Spelling it "hemiazygous" when referring to the vein is incorrect, regardless of whether British or American English 5. In the context of anatomy, see Terminologia Anatomica, hemiazygos vein is the sole correct spelling.
Gross anatomy
Origin and course
The accessory hemiazygos vein is formed by the confluence of the middle left posterior intercostal veins. It descends to the left of midline, adjacent to the thoracic vertebrae and crosses posteriorly to the aorta at the level of T7-8 to drain into the azygos vein. It normally anastomoses with the left superior intercostal vein.
Tributaries
- left 4th-8th posterior intercostal veins
- left bronchial veins (variable)
Variant anatomy
- drains via a common trunk with the hemiazygos vein into the azygos vein
- forms a common trunk with the hemiazygos vein that passes anterior to the aorta called the interazygos vein 2
- drains directly into the left brachiocephalic vein (rare) 2
-<p>The <strong>accessory</strong> (or <strong>superior</strong>) <strong>hemiazygos</strong> <strong>vein</strong> forms part of the <a href="/articles/azygos-venous-system">azygos system</a> and along with the <a href="/articles/hemiazygos-vein">hemiazygos</a> vein, it is partially analogous to the right-sided <a href="/articles/azygos-vein">azygos vein</a>. It drains the left superior hemithorax. </p><h4>Gross anatomy</h4><h5>Origin and course</h5><p>The accessory hemiazygos vein is formed by the confluence of the middle left posterior intercostal veins. It descends to the left of midline, adjacent to the thoracic vertebrae and crosses posteriorly to the aorta at the level of T7-8 to drain into the azygos vein. It normally anastomoses with the <a href="/articles/left-superior-intercostal-vein">left superior intercostal vein</a>.</p><h5>Tributaries</h5><ul>- +<p>The <strong>accessory</strong> (or <strong>superior</strong>) <strong>hemiazygos</strong> <strong>vein</strong> forms part of the <a href="/articles/azygos-venous-system">azygos system</a> and along with the <a href="/articles/hemiazygos-vein">hemiazygos</a> vein, it is partially analogous to the right-sided <a href="/articles/azygos-vein">azygos vein</a>. It drains the left superior hemithorax. </p><h4>Terminology</h4><p>Spelling it "hemiazygous" when referring to the vein is incorrect, regardless of whether British or American English <sup>5</sup>. In the context of anatomy, see <a href="/articles/terminologia-anatomica-1">Terminologia Anatomica</a>, hemiazygos vein is the sole correct spelling.</p><h4>Gross anatomy</h4><h5>Origin and course</h5><p>The accessory hemiazygos vein is formed by the confluence of the middle left posterior intercostal veins. It descends to the left of midline, adjacent to the thoracic vertebrae and crosses posteriorly to the aorta at the level of T7-8 to drain into the azygos vein. It normally anastomoses with the <a href="/articles/left-superior-intercostal-vein">left superior intercostal vein</a>.</p><h5>Tributaries</h5><ul>
References changed:
- 5. Holemans JA. Azygos, not azygous. (2001) AJR. American journal of roentgenology. 176 (6): 1602. <a href="https://doi.org/10.2214/ajr.176.6.1761602b">doi:10.2214/ajr.176.6.1761602b</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/11373246">Pubmed</a> <span class="ref_v4"></span>
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