Endovascular mesenteric revascularization carries definitive risk. The average 30-day mortality in a recent systematic review was 6 % (0–21 %), surpassing the mortality reported for other types of endovascular interventions, including aortic, renal, and carotid procedures. Even though most interventions are done using local anesthesia, these patients typically undergo a comprehensive medical evaluation to identify and optimize cardiovascular risk factors and their nutritional status. Many of the comorbidities may require medical therapy to be started prior or after the intervention, depending on its severity. Revascularization should not be excessively delayed. Patients who present with deterioration of symptoms should be admitted, started on intravenous heparin, and treated urgently within 24–48 h. Patients with iodinated contrast allergy should be premedicated with steroid preparation. Those with chronic kidney disease who have serum creatinine level >1.5–2.0 mg/dL (133–177 Mmol/L) undergo intravenous hydration with sodium bicarbonate and oral acetylcysteine, starting the day prior to intervention. Review of pre-procedure imaging (CTA, MRA, or conventional angiography) is key to select the ideal approach based on the angle of origin of the mesenteric vessels in relation to the aortic axis, the amount of calcium and thrombus load, and the presence of important collaterals or unusual anatomy (e.g., replaced hepatic) in proximity to the target lesion.

The choice of ideal access is dependent on vessel anatomy, extent of occlusive disease, angle of origin from the aorta, and physician preference. The advantages of femoral approach include the frequent use and familiarity, ability to use shorter delivery system, and most importantly the exceedingly low rate of access site complications. However, because the CA and superior mesenteric artery (SMA) have acute angle of origin from the aorta, mesenteric interventions can be difficult to perform via the femoral approach. Excessive angulation often results in added time and radiation exposure, multiple guidewire exchanges, and in some cases, treatment failure.

Therefore, the ideal approach remains controversial. The author’s preference is to use the left brachial artery access with a small 1–2 cm incision to surgically expose the artery. This is done under local anesthesia. Brachial access is particularly beneficial in the patient with difficult anatomy, such as those with flush occlusions, acute aortic angles, or long-segment lesions affected by very high-grade stenosis. Although the use of brachial access has been associated with higher rate of local complications when done totally percutaneously, it may reduce rate of severe mesenteric artery complications including dissections, vessel perforations, and embolization. Finally, we have increasingly utilized the radial artery access, but this is limited by need for longer delivery system and smaller profile sheath and devices.

Diagnostic angiography has been discussed in detail in Chap. 2 (Fig. 13.3). Diagnostic angiography is most often done immediately prior to a planned intervention, either through the femoral or brachial approach. Access is established using ultrasound guidance and 0.035 in guidewire system. A 5 Fr sheath is positioned in the external iliac artery, and 5 Fr diagnostic flush catheter is advanced to T12 level over a 0.035 in guidewire. Modest intravenous heparinization (40 units/kg) is recommended prior to selective catheterization of the mesenteric arteries. Low-osmolar contrast agent (e.g., Visipaque®) minimizes abdominal discomfort during selective injections. Choice of catheter shape is dependent upon access site, angle of origin, and individual preference. MPA catheter is ideal for selective catheterization via brachial approach, whereas a secondary curve catheter (e.g., SOS or Simmons) or a catheter with more acute curve (e.g., Cobra 2) can be used for interventions done via femoral approach (Fig. 13.4). A complete study includes abdominal aortogram with anterior-posterior and lateral views to define the location, severity, and extent of visceral artery involvement and to identify concomitant lesions in the aorta, renal, or iliac arteries. The optimal projection to display the proximal CA and SMA is a lateral view, and for the origin of the IMA, it is a 15° right lateral-oblique view. Selective angiography is necessary to confirm the severity of disease and to identify tandem lesions and collateral patterns. In patients with questionable lesions, pressure gradients can be measured using pressure wire, “pull-back,” or simultaneous pressure measurement technique [26].

Selective catheterization requires systemic heparinization (80 mg/kg), which should be administered prior to catheter manipulations in order to achieve an activated clotting time over 250 s. Using the brachial artery access, a 6 or 7 Fr 90 cm hydrophilic sheath is positioned in the descending thoracic aorta above the CA origin. A 5 Fr MPA catheter is ideal for selective catheterization of the mesenteric arteries using the brachial approach, whereas a SOS or VS1 catheter can be used from the femoral approach. The initial selective angiography should demonstrate the origin of the vessel from the aortic wall and the severity of the stenosis and should document the distal branches for comparison with post-intervention views.

The target lesion is initially crossed using a 0.035 in soft angled glidewire, which is exchanged for the interventional wire of choice after confirmation of true lumen access. The authors’ preference is to use a small profile (0.014 or 0.018 in) stiff guidewire for most interventions. The tip of the guidewire should be visualized and positioned within the main trunk of the SMA, rather than within small jejunal branches, which are prone to perforate or dissect.

The use of embolic protection devices is highly controversial. The potential advantage is limiting or preventing distal embolization, which has been described as a known intraprocedural complication and cause of death after mesenteric interventions. Limitations include the added cost and the potential risk of arterial damage by the filter basket. In addition, there is limited information on which is the ideal filter device and where it should be placed within the mesenteric vessel. The Mayo Clinic group has reviewed the anatomy of the SMA to identify diameter and number of jejunal branches. Most patients have an average of 13 major jejunal branches, and >90 % of these branches originate >5 cm distal to the aortic origin of the SMA. The average diameter of the SMA in this location is 5–6 mm. Therefore, the most frequently utilized filter device would be a 7-mm filter basket positioned approximately 5 cm distal to the SMA origin.

In our experience, embolic protection devices are used selectively. Patients with acute or subacute mesenteric ischemia have a component of fresh in situ thrombosis and may be more prone to distal embolization. Among patients with chronic lesions, we found higher embolization rates in those with occlusions, severe calcification, and lesions longer than 30 mm. The author recommends use of embolic protection in these situations [22]. Our preference is to use a 320 cm working length 0.014 in filter wire (Spider RX, Covidien, Plymouth, MN; Fig. 13.5). Alternatively, Brown and associates described the use of temporary balloon occlusion and aspiration with GuardWire (Medtronic, Minneapolis, MN) [27]. If a 0.035 in stent is selected, a two-wire technique can be used by combining a 0.014 in filter wire with a 0.018 in “buddy wire.” The stent is introduced via both wires for better support and to facilitate subsequent retrieval of the embolic protection device.

The vast majority of patients (>90 %) are treated using balloon-expandable stents. These have the advantages of wide range of length, precise deployment, and radial force. Because mesenteric lesions mimic renal artery lesions and are ostial and highly calcified, precise deployment and radial force are major advantages. Nonetheless, longer lesions affecting the bend of the SMA or those in tortuous segments may not be ideally suited for balloon-expandable stents. In these cases a short self-expandable stent may be used. If the lesion is long, it is not uncommon to combine a balloon-expandable stent for the ostia of the lesion with a self-expandable stent distally. Finally, we have recently shifted our practice to use preferentially covered balloon-expandable stents, which are resistant to intimal hyperplasia and have higher patency rates compared to bare metal stents. Covered stents are avoided in segments with critical side branches, which need to be preserved.

The primary goal of percutaneous treatment is to restore antegrade flow into at least one of the three mesenteric arteries, preferentially the SMA. First reports described successful results with balloon angioplasty alone, but elastic recoil and restenosis have limited its utility when used for ostial lesions [18, 28–37]. Although there are no prospective comparisons between angioplasty alone and primary stenting, most agree that routine stenting is indicated given that mesenteric lesions resemble renal artery stenoses [21, 27, 38–51]. Although there are no randomized comparisons between SMA and celiac stent placement, retrospective studies suggest that celiac stenting is associated with more recurrences in the first year after treatment [21]. In patients with compression of the CA by the median arcuate ligament, there is risk of stent fracture and compression. The role of two-vessel stenting remains controversial. Two retrospective studies by the MGH group and by Silva and colleagues have shown a nonsignificant trend towards less recurrence with two-vessel stenting [43, 46]. Malgor and colleagues from the Mayo Clinic reported nearly identical recurrence rates at 2 years in patients treated by SMA stents (78 %) compared to two-vessel stenting of the SMA and CA (60 %). Two-vessel mesenteric interventions may have a role in select patients with severe gastric ischemia and who do not have good collateral network between the CA and SMA. However, there is no proven benefit that routine two-vessel stenting provides more durable relief, and a second intervention adds cost and potential risk of complications.

CA intervention may be considered in higher-risk patient who fails attempted recanalization of the SMA or in those where an SMA intervention is felt to have a low yield for success due to excessive calcification or long-segment occlusion. In these patients, celiac stenting may be considered a “bridge” to open bypass or retrograde SMA stenting [52]. Angioplasty of the IMA in our experience carries a higher risk of rupture, dissection, or embolization, and is not advised with rare exceptions.

A brachial artery approach is preferred for patients with very angulated origin of the aorta and in those with occlusions or longer lesions. The author’s preference is to use brachial artery approach whenever possible (Fig. 13.5). This offers excellent support with small profile system and precise stent deployment in patients with acute SMA angle. Although the risk of puncture-related complications is higher using total percutaneous technique, one option is to use a small 1–2 cm incision under local anesthesia to expose and repair of the brachial artery; less frequently, radial approach has been used.

Percutaneous access is established with a 0.018 in micropuncture set using ultrasound guidance, after which the system is exchanged to 0.035 in. Full systemic heparinization (80 mg/kg) is administered prior to catheter manipulations to achieve an activated clotting time of >250 s. A 6 or 7 Fr 90 cm hydrophilic sheath is positioned in the descending thoracic aorta above the CA origin. A 5 Fr MPA catheter is ideal for selective catheterization of the mesenteric arteries using the brachial approach, whereas a SOS or VS1 catheter can be used from the femoral approach. The initial selective angiography should demonstrate the origin of the vessel from the aortic wall and the severity of the stenosis and should document the distal branches for comparison with post-intervention views. The target lesion is initially crossed using a 0.035 in soft angled glidewire, which is exchanged for the interventional wire of choice after confirmation of true lumen access. The author’s preference is to use a small profile (0.014 or 0.018 in) stiff guidewire for most interventions. Most recently, our practice has changed to covered stents, based on a recent report which indicates superior patency rates compared to bare metal stents [53]. The tip of the guidewire should be visualized and positioned within the main trunk of the SMA, rather than within small jejunal branches, which are prone to perforate or dissect (Fig. 13.6). Embolic protection may be useful in select patients with occlusions, long lesions (>30 mm length), severe calcification, thrombus, and acute or subacute symptoms; the author’s preference is to use a 320 cm working length 0.014 in filter wire (Spider RX, Covidien, Plymouth MN). Alternatively, Brown and associates described the use of temporary balloon occlusion and aspiration with GuardWire (Medtronic, Minneapolis, MN) [27]. If a 0.035 in stent is selected, a two-wire technique can be used by combining a 0.014 in filter wire with a 0.018 in “buddy wire”; the stent is introduced via both wires for better support and to facilitate subsequent retrieval of the embolic protection device (Fig. 13.5). Pre-dilatation is recommended for tight stenosis, occlusions, severe calcification, and to size stents. A balloon-expandable stent with diameters ranging from 5 to 8 mm is used in >95 % of cases, allowing precise deployment and greater radial force. The stent is positioned under protection of the sheath, covering slightly more than the entire length of the lesion. Positioning the stent in the aortic lumen is critical to avoid missing the proximal portion of the lesion. It is important to position the stent 1–2 mm into the aortic lumen (Fig. 13.5). Ideally, the stent should be flared gently into the aorta, which prevents missing the ostia and facilitates re-catheterization if needed. Occasionally a self-expandable stent is needed to treat a non-ostial lesion or segments with excessive tortuosity, extending beyond the angulated portion of the SMA.