上腸間膜動脈の形成についての論文が掲載

胚子期ー胎児期初期の上腸間膜動脈の特徴について検討した論文がCells Tissues Organsに掲載されました。掛谷さん、石田さんがおもに解析をした研究です。

中腸ループの臍帯ヘルニア期から還納期の上腸間膜動脈の形態の特徴について、しっかりと検討した論文はこれまでありません。

• SMAはほぼ等間隔で11−14の小腸枝を萌出する
• 第4小腸枝が最長で第５以降の長さは漸減することが多い
• 各小腸枝において、基部は分岐は少なく、末梢の腸管近傍で分岐回数を増やす、相互の吻合は未発達
• これらの特徴は中腸ループの臍帯内から腹腔への移動時に血流不全等のアクシデントが生じにくいという点で適合している
• 中腸の領域、ループとの関係は厳密な対応はしない
• 個体間の差はある程度みられる点は他の動脈と同じ

Takakuwa T, Kakeya M, Ishida N, Kanahashi T, Fujii S, Männer J, Yamada S. Superior mesenteric artery during intestinal loop formation and its positional changes from the extracoelom to the abdominal cavity. Cells Tissues Organs 2026, 215, 1, (1-12), DOI: 10.1159/000545751

Abstract

Introduction: Features of the superior mesenteric artery (SMA) and its intestinal branches during the embryonic and early fetal periods have not been fully described. We aimed to comprehensively elucidate the characteristics of intestinal branch artery formation in the SMA.
Methods: Serial tissue sections of seven early fetal specimens belonging to the Blechschmidt Collection were digitalized and used for segmentation and reconstruction of the intestinal loop, SMA trunk, intestinal branch arteries, and mesentery for further analysis.
Results: The intestinal branch arteries fed the intestinal tract from the oral side to the anal side, according to the order of their origin from the root to the periphery of the SMA trunk. SMA and intestinal branches were not as strongly conserved in their morphology as indicated in previous research but varied between specimens. Most intestinal branch arteries exhibited frequent branching with small intervals at the periphery, whereas the proximal branch exhibited few branches. Only a few peripheral branches made contact with the neighboring intestinal branch arteries. The fetal intestinal branch artery architecture differed greatly from that of adults. There were considerable inter- and intra-specimen variations in the intestinal tract length per feeding intestinal branch artery. The SMA branching arteries did not always supply each tertiary loop individually, and not every loop is connected to one branching artery.
Conclusion: This study elucidates the characteristics of forming the SMA intestinal branch arteries. Specifically, the findings suggest that the SMA is similar to other arteries in that its branches show a level of variability in feeding tissues.