Kitamura S, Nishiguchi T, Sakai A, Kumamoto K
Second Department of Oral Anatomy, Osaka University Faculty of Dentistry, Japan.
Anat Rec. 1987 Jan;217(1):99-102. doi: 10.1002/ar.1092170113.
The authors observed a variation of the inferior mesenteric artery, which arose from the superior mesenteric artery, in a 69-year-old Japanese male cadaver during dissection in 1984. In this case, no rudiment of the ordinary inferior mesenteric artery could be found on the abdominal aorta. There are few reports of this variation, and an extensive search of the available literature revealed only four cases, including two in Japan. Such a variation had been somewhat inadequately described as an "absence of the inferior mesenteric artery" in the previous reports, but we avoided this terminology, because all of the cases possessed an artery, which, though arising from the superior mesenteric artery instead of the abdominal aorta, had the same branches as a normal inferior mesenteric artery. Consistent with findings observed in the previous cases, the unusual inferior mesenteric artery arose as the first branch of the superior mesenteric artery, with the common trunk of both mesenteric arteries originating from the abdominal aorta at a level at which an ordinary superior mesenteric artery would arise. It is for this reason that we did not adopt another acceptable name, that is, "the common mesenteric artery," for this variation. The variation can be explained as the result of an unusual development of the embryonic artery system, which comprises a number of ventral splanchnic arteries interconnected by longitudinal anastomotic channels to supply the primitive digestive tube.
1984年，作者在解剖一具69岁的日本男性尸体时，观察到肠系膜下动脉变异，该变异动脉起源于肠系膜上动脉。在此病例中，腹主动脉上未发现正常肠系膜下动脉的遗迹。关于这种变异的报道很少，广泛查阅现有文献仅发现4例，其中2例来自日本。此前的报告曾将这种变异 somewhat inadequately 描述为“肠系膜下动脉缺如”，但我们避免使用该术语，因为所有病例均存在一条动脉，尽管它起源于肠系膜上动脉而非腹主动脉，但其分支与正常肠系膜下动脉相同。与之前病例的观察结果一致，这条异常的肠系膜下动脉作为肠系膜上动脉的第一分支发出，两条肠系膜动脉的共同主干起源于腹主动脉上正常肠系膜上动脉起始的水平。正是出于这个原因，我们没有为这种变异采用另一个可接受的名称，即“共同肠系膜动脉”。这种变异可以解释为胚胎动脉系统异常发育的结果，胚胎动脉系统由许多通过纵向吻合通道相互连接的腹侧内脏动脉组成，以供应原始消化管。
