The Arc of Bühler: A Cadaveric Case Report of a Novel Variant.

The arc of Bühler (AOB) is a rare variant in the vasculature of the foregut and midgut. It forms as a direct anastomosis between the celiac trunk and the superior mesenteric artery or their branches. Here, we describe an unusually large AOB with a previously unreported pattern of anastomosis. The variant was discovered and documented during routine cadaveric dissection by first-year osteopathic medical students. The AOB arose from the celiac trunk and was similar in diameter to the splenic and common hepatic arteries. The AOB measured approximately 38 cm in total length along its pathway and terminated at the superior mesenteric artery. It varied in diameter from 4 mm to approximately 9-10 mm. Its connections to the surrounding viscera indicated that it supplied blood to the regions typically supplied by the right and middle colic arteries, which were not present as separate structures in the individual. A branch connected the AOB to the inferior pancreaticoduodenal artery at its origin from the posterior surface of the superior mesenteric artery. A review of the literature on AOB variants indicates that the pattern of branching reported here has not been described before. Patterns of anastomosis are clinically important because of their potential roles in pathophysiology (e.g., aneurysm, ischemia) and surgical procedures. Our findings highlight the importance of identifying this anatomical variant preoperatively and adjusting medical management accordingly, which can yield effective clinical results and potentially lower the risk of significant surgical complications in patients.