Question

A $78$-year-old woman is evaluated in the emergency department for severe, diffuse abdominal pain that began suddenly $3$ hours ago. She has a history of atrial fibrillation, hypertension, and type 2 diabetes mellitus. She stopped taking apixaban two months ago due to financial difficulties. On physical examination, she appears distressed and diaphoretic. Temperature is $38.1^\circ C$ ($100.6^\circ F$), pulse is $122/min$ and irregularly irregular, blood pressure is $90/60$ $mm Hg$, and respirations are $24/min$. Abdominal examination reveals a slightly distended abdomen that is soft, with only mild tenderness to deep palpation and no rebound or guarding. Bowel sounds are diminished. Laboratory studies show a leukocyte count of $18,500/mm^3$ and serum lactate of $5.2$ $mmol/L$. A contrast-enhanced computed tomography (CT) scan of the abdomen and pelvis is performed. The radiologist's report notes an abrupt filling defect in the superior mesenteric artery, along with linear radiolucencies tracking parallel to the wall of the small bowel and branching tubular radiolucencies extending to the periphery of the liver. Based on the described imaging findings, which of the following is the most appropriate next step in management?