A case of abnormally dilated and tortuous arc of Buhler and pancreaticoduodenal arteries in the absence of celiac trunk stenosis.

INTRODUCTION: The Arc of Buhler is a rare vascular variant describing a persistent remnant of the embryologic ventral anastomosis between the celiac trunk (CT) and superior mesenteric artery (SMA), invariably reported in the context of CT stenosis. PURPOSE: To report a case of (1) a large and tortuous pancreaticoduodenal arcade and (2) a large and tortuous Arc of Buhler in the absence of celiac axis stenosis. METHODS: The variant was discovered during routine cadaver dissection. We acquired transverse biopsies of variant vessels and evaluated their wall thickness. RESULTS: The donor's anterior PDA, posterior PDA, and Arc of Buhler had larger diameters, and the common hepatic artery had a smaller diameter than the literature-reported values of a standard human body. The posterior PDA had significantly increased wall thickness compared to the other investigated vessels. CONCLUSIONS: The Arc of Buhler is a rare remnant of the embryologic ventral anastomosis that is estimated to be hemodynamically active in only half of cases. Previous reports have documented hemodynamically active Arcs of Buhler only in cases of CT stenosis. To the best of the authors' knowledge, this is a unique case of a persistent and hemodynamically active Arc of Buhler in the absence of CT stenosis. Clinicians should be aware of this variant as its abnormal position may increase risk of herniation and surgical complications, and its tortuosity may increase risk of clot formation.

Vascular Smooth Muscle Sirtuin-1 Protects Against Diet-Induced Aortic Stiffness.

Arterial stiffness, a major cardiovascular risk factor, develops within 2 months in mice fed a high-fat, high-sucrose (HFHS) diet, serving as a model of human metabolic syndrome, and it is associated with activation of proinflammatory and oxidant pathways in vascular smooth muscle (VSM) cells. Sirtuin-1 (SirT1) is an NAD(+)-dependent deacetylase regulated by the cellular metabolic status. Our goal was to study the effects of VSM SirT1 on arterial stiffness in the context of diet-induced metabolic syndrome. Overnight fasting acutely decreased arterial stiffness, measured in vivo by pulse wave velocity, in mice fed HFHS for 2 or 8 months, but not in mice lacking SirT1 in VSM (SMKO). Similarly, VSM-specific genetic SirT1 overexpression (SMTG) prevented pulse wave velocity increases induced by HFHS feeding, during 8 months. Administration of resveratrol or S17834, 2 polyphenolic compounds known to activate SirT1, prevented HFHS-induced arterial stiffness and were mimicked by global SirT1 overexpression (SirT1 bacterial artificial chromosome overexpressor), without evident metabolic improvements. In addition, HFHS-induced pulse wave velocity increases were reversed by 1-week treatment with a specific, small molecule SirT1 activator (SRT1720). These beneficial effects of pharmacological or genetic SirT1 activation, against HFHS-induced arterial stiffness, were associated with a decrease in nuclear factor kappa light chain enhancer of activated B cells (NFκB) activation and vascular cell adhesion molecule (VCAM-1) and p47phox protein expressions, in aorta and VSM cells. In conclusion, VSM SirT1 activation decreases arterial stiffness in the setting of obesity by stimulating anti-inflammatory and antioxidant pathways in the aorta. SirT1 activators may represent a novel therapeutic approach to prevent arterial stiffness and associated cardiovascular complications in overweight/obese individuals with metabolic syndrome.