Abstract：
The thyroidea ima artery (TIA) is a highly variable arterial deviation of the blood supply to the thyroid gland with critical implications for surgical neck procedures such as tracheostomy. Though relatively common in the population at large (~ 4%), most TIA variations are related to the origin of the artery and whether it emerges from the common sites of the brachiocephalic trunk, aortic arch, and right common carotid artery, or another more unique vessel-as opposed to its dispersion pattern. TIA variants generally supply the thyroid gland, occasionally co-occurring with absent thyroid arteries. Here, we report on a unique case of a four-pronged variation of the TIA discovered during an anatomy laboratory dissection of first-year medical students. This variant originated from the brachiocephalic trunk and had three branches terminating in the thyroid gland and a fourth branch traveling into the thorax to provide accessory circulation in the mediastinum. Specifically, small arterial branches from the inferior TIA branch supplied the anterior pericardium and surrounding adipose tissue, in addition to normal pericardiacophrenic circulation. We discuss the potential embryological and clinical relevance of this unique variation and voice further support for imaging as a requirement before surgical neck procedures to prevent catastrophic bleeding in the event of a TIA variant.
摘要：
甲状腺动脉（TIA）是甲状腺血液供应的高度可变的动脉偏差，对诸如气管造口术的颈部外科手术具有重要意义。虽然在一般人群中相对常见(约4%)，大多数TIA变异与动脉的起源以及是否从头臂干的常见部位出现有关，主动脉弓,和右颈总动脉,或者另一个更独特的船只-与其分散模式相反。TIA变体通常供应甲状腺，偶尔伴有甲状腺动脉缺失。这里,我们报告了在一年级医学生的解剖学实验室解剖中发现的TIA四管齐下变异的独特病例。此变体起源于头臂干，有三个分支终止于甲状腺，第四个分支进入胸部以在纵隔中提供辅助循环。具体来说,下TIA分支的小动脉分支供应心包和周围脂肪组织，除了正常的心包膈循环。我们讨论了这种独特变化的潜在胚胎学和临床相关性，并进一步支持在手术颈部手术之前进行成像，以防止发生TIA变异时发生灾难性出血。
