Collateral circulation develops in stenosis of the celiac trunk and superior mesenteric artery

Revascularization of superior mesenteric artery occlusion via the arc of Buhler: A case report and literature review

BACKGROUND

To report revascularization of a superior mesenteric artery (SMA) ostial occlusion via the Arc of Buhler.

CASE REPORT

A 62-year-old female presented with 2 months of recurrent abdominal distension and postprandial pain. Computed tomography angiography (CTA) revealed ostial occlusion of the SMA with distal perfusion via the Arc of Buhler (connecting the celiac trunk and SMA). Conventional endovascular techniques failed. A 0.014 guidewire was passed retrograde through the occlusion via the Arc of Buhler. The guidewire was captured from the femoral sheath and balloon angioplasty with stent placement was performed. The patient had complete symptom resolution post-procedure.

CONCLUSIONS

Retrograde revascularization via the Arc of Buhler is an effective method for treating the initial segment occlusion of the SMA.

Impact of hyperoxia on the gut during critical illnesses

Molecular oxygen is typically delivered to patients via oxygen inhalation or extracorporeal membrane oxygenation (ECMO), potentially resulting in systemic hyperoxia from liberal oxygen inhalation or localized hyperoxia in the lower body from peripheral venoarterial (VA) ECMO. Consequently, this exposes the gastrointestinal tract to excessive oxygen levels. Hyperoxia can trigger organ damage due to the overproduction of reactive oxygen species and is associated with increased mortality. The gut and gut microbiome play pivotal roles in critical illnesses and even small variations in oxygen levels can have a dramatic influence on the physiology and ecology of gut microbes. Here, we reviewed the emerging preclinical evidence which highlights how excessive inhaled oxygen can provoke diffuse villous damage, barrier dysfunction in the gut, and gut dysbiosis. The hallmark of this dysbiosis includes the expansion of oxygen-tolerant pathogens (e.g., Enterobacteriaceae) and the depletion of beneficial oxygen-intolerant microbes (e.g., Muribaculaceae). Furthermore, we discussed potential impact of oxygen on the gut in various underlying critical illnesses involving inspiratory oxygen and peripheral VA-ECMO. Currently, the available findings in this area are somewhat controversial, and a consensus has not yet to be reached. It appears that targeting near-physiological oxygenation levels may offer a means to avoid hyperoxia-induced gut injury and hypoxia-induced mesenteric ischemia. However, the optimal oxygenation target may vary depending on special clinical conditions, including acute hypoxia in adults and neonates, as well as particular patients undergoing gastrointestinal surgery or VA-ECMO support. Last, we outlined the current challenges and the need for future studies in this area. Insights into this vital ongoing research can assist clinicians in optimizing oxygenation for critically ill patients.