Chronic Mesenteric Ischemia

Indications

The natural history of mesenteric arterial disease is not well defined. In the only study published to date, a retrospective analysis revealed that 23% of asymptomatic patients who were noted to have disease of all three mesenteric arteries at the time of aortography (performed for other reasons) developed symptoms of, or sequelae related to, mesenteric ischemia during a 7-year period of follow-up. Therefore, given the paucity of data about the natural history of mesenteric arterial occlusive disease, the most common indication for treatment of stenoses or occlusions of the mesenteric arteries is the presence of ischemic symptoms. Based on the surgical literature involving aortic reconstruction for aneurysmal or occlusive disease, mesenteric arterial reconstruction should be performed routinely even in asymptomatic patients, because these patients have a poorer postoperative course if their mesenteric vascular disease is not corrected at the time of their aortic surgery. The topic of aggressive treatment in asymptomatic patients with mesenteric arterial occlusive disease when there is no need for aortic reconstruction is where the controversy begins. On occasion, surgical colleagues may request interventionists to perform mesenteric arteriography and potential optimization of the mesenteric flow before complex cardiac operations. We believe that even in asymptomatic patients, the presence of significant three-vessel mesenteric arterial occlusive disease warrants strong consideration for revascularization, especially if endovascular therapy is feasible. An isolated asymptomatic mesenteric arterial stenosis should be managed on a case-by-case basis because many of these patients may never become symptomatic, therefore mesenteric arterial intervention may not be needed.

Contraindications

Symptomatic median arcuate ligament (MAL) compression of the celiac artery is best treated by surgical release of the ligament; use of a stent is this situation is not advised. Balloon-expandable stents placed in an artery compressed by the MAL may be crushed and/or fractured by extrinsic compression of the stent by the ligament. Self-expanding stents do not have enough radial strength to resist external compression and are likely to fracture over time. More importantly, symptoms related to the MAL are most likely neurogenic, owing to compression of the celiac ganglion. Therefore, placement of a stent in the celiac artery may actually exacerbate the symptoms. However, on a case-by-case basis, endovascular intervention may be beneficial after surgical release of the MAL in patients with heavy calcifications at the origin of the celiac artery. An extraanatomic surgical bypass procedure may also be a good alternative option.

Equipment

• Fifty to 100 mL of iodine-based contrast. Alternatively, CO ₂ may be used judiciously in patients at risk for contrast-induced nephropathy.

• A multi-sidehole catheter for aortography and selective catheters (RC 1, Simmons 1, Rösch inferior mesenteric, or SOS Omni 2 [AngioDynamics, Glens Falls, NY]), depending on the anatomy, are used for selective catheterization of the mesenteric arteries.

• Radial arterial access/approach is being used more often, especially among younger interventional radiologists. This approach may be helpful, especially for interventions that involve a mesenteric artery with an acute caudal angle from the aorta.

• Use of a guiding sheath or guiding catheter of proper size and shape during a procedure performed from a common femoral artery approach will facilitate delivery of a balloon catheter and/or stent ( Fig. 29.2A, B, and D ) and allow for contrast injections to assess results of the intervention. Several types of tip-deflecting sheaths or catheters are commercially available to facilitate delivery of devices into an acutely angled mesenteric from the femoral artery approach.

  

• Pressure transducers that can be connected to catheters or pressure wires for measurement of translesion pressure gradients should be available to determine the hemodynamic significance of questionable stenosis and the subsequent results of the intervention.

• A variety of 0.035-inch, 0.018-inch, or 0.014-inch guidewires and compatible balloon and stent platforms are recommended.

• Heparin, nitroglycerin, conscious sedation medications, oral antiplatelet agents, prophylactic antibiotics before stent placement, closure devices (as needed for femoral punctures), and appropriate patient monitoring equipment (pulse oximetry, electrocardiogram, blood pressure, and heart rate) should also be available before starting the procedure.

• High-resolution digital subtraction angiography equipment that allows for multiplanar imaging, an experienced interventionalist, a nurse dedicated to patient monitoring during the procedure, and a well-trained technologist are also essential for procedural success.