中动脉是一种短暂的胚胎结构,通常随着桡动脉和尺动脉的发育而消失。在极少数情况下,虽然,它作为持续性正中动脉(PMA)持续存在。浅掌弓和深掌弓是通过桡动脉和尺动脉的吻合形成的,给手和手指主要的血液供应。基于吻合如何发生以及哪些动脉有助于这种吻合,这种复杂的血管网络及其吻合易于发生解剖学变化。虽然它通常通过桡动脉和尺动脉的吻合形成,掌浅弓(SPA)也可能形成不同的形式,就像我们这里的情况一样,正中动脉持续存在并从桡动脉分支出来,与尺动脉吻合以产生SPA。这也可能会干扰手中的正常隔室结构,可能导致各种临床病理,如腕管综合征(CTS)。值得注意的是,除了持续性的正中动脉,我们的发现揭示了一个逆转的掌长和一个双裂的正中神经。这两个额外的变化可能潜在地加剧CTS的风险。独自一人,PMA和反向掌长的共存被认为是罕见的异常,文献中只报道过一次。在现有的基础上增加了第三种变化,像双裂正中神经一样,这是我们首次报道的,并呼吁对可能的基因突变进行更多的调查。在这种情况下,我们报告了一个持续性的正中动脉,掌长肌逆转,和在常规解剖学教学中发现的男性尸体前臂的双裂正中神经。
The median artery is a transient embryological structure that normally disappears with the development of the radial and ulnar arteries. In rare instances, though, it persists as the persistent median artery (
PMA). The superficial and deep palmar arches are formed through the anastomoses of the radial and ulnar arteries, giving hand and digits their main blood supply. This complex network of vessels and their anastomoses are prone to anatomical variations based on how the anastomosis occurs and which arteries contribute to this anastomosis. While it normally forms through the anastomosis of the radial and ulnar arteries, the superficial palmar arch (SPA) may also form differently, as in our
case here, where the median artery persisted and branched off the radial artery, anastomosing with the ulnar artery to give rise to the SPA. This may also interfere with the normal compartmental architecture within the hand, possibly contributing to various clinical pathologies like carpal tunnel syndrome (CTS). Notably, in addition to the persistent median artery, our findings revealed a reversed palmaris longus and a bifid median nerve. These two additional variations can potentially exacerbate the risk of CTS. Alone, the coexistence of the
PMA and the reversed palmaris longus is deemed a rare anomaly, only reported once in the literature. The addition of a third variation to the existing ones, like the bifid median nerve, is first reported by us and calls for more investigation for a possible genetic mutation. In this
case, we report a persistent median artery, reversed palmaris longus muscle, and bifid median nerve in the forearm of a male cadaver found during a routine anatomy teaching session.