a Department of Anatomy and Animal Production; Faculty of Veterinary Sciences ; University of Santiago de Compostela; Campus of Lugo ; Lugo , Spain.
Organogenesis. 2014;10(3):312-6. doi: 10.4161/15476278.2014.970090.
Congenital defects are those abnormalities present at birth. During embryogenesis, many anomalies can occur. The primitive gut tube lengthens quickly and rotates, allowing the gastrointestinal tract acquire its final position and orientation. Because the colon of large animals is complex, most changes occur in this segment. Thus, in ruminants, colon atresia is the most frequent malformation, affecting mainly ascending colon, at the level of the spiral loop. There are no previous references about a very atypical colon atresia at the junction of distal loop and transverse colon, such we have described in a 5-day-old calf, after a history of abdominal distention and absence of feces at birth, even with a patent anal opening. Atresia coli was detected at distal position of the typical colon atresia, at the junction of distal loop and transverse colon. In addition, the distal blind end was bent into a U-shape supported by the mesocolon. Besides the anatomical findings of this worthwhile atresia coli we discuss its possible etiology, in which local factors, such as a compromised blood supply during embryogenesis, are more consistent than genetic factors. Finding out the causes of atresia coli would help to reduce its incidence, lessen animal suffering and economic loss.
先天性缺陷是指出生时就存在的异常。在胚胎发生过程中，可能会发生许多异常。原始的肠道管迅速延长并旋转，使胃肠道获得其最终的位置和方向。由于大型动物的结肠结构复杂，大多数变化发生在这个部位。因此，在反刍动物中，结肠闭锁是最常见的畸形，主要影响螺旋环水平的升结肠。此前没有关于非常典型的结肠闭锁在远环和横结肠交界处的报告，我们在一只 5 天大的小牛中描述了这种情况，该小牛在出生时出现腹胀和无粪便，尽管肛门开口通畅。在典型的结肠闭锁的远端位置，即在远环和横结肠交界处发现了结肠闭锁。此外，远侧盲端弯曲成 U 形，由系膜支撑。除了这种值得关注的结肠闭锁的解剖学发现，我们还讨论了其可能的病因，其中胚胎发生期间局部供血不足等因素比遗传因素更一致。了解结肠闭锁的原因将有助于降低其发病率，减轻动物的痛苦和经济损失。
