These case reports demonstrate that modern endovascular techniques enable to revascularize not only the main stem of the SMA but also its side branches. Usually we catheterize the SMA with a 5 French Cobra or Celiac catheter and then exchange over a teflon 0.035″ wire for a 6 French guiding sheath, for example a hydrophylic Flexor Balkin (Cook Medical, Bloomington, USA). In case of a proximal stenosis or steep angulation of the main stem of the SMA a steerable sheath (TourGuide steerable sheath, Medtronic, Minneapolis, USA) can be chosen. Due to the adjustable tip angulation the acute angulation of the SMA is less challenging and a stable position can be reached.
Once a stable position with a guiding sheath has been obtained, mechanical thrombosuction (Indigo System CAT6 aspiration catheter Penumbra, Alameda, USA) for both main stem and sidebranches can be performed. If there is a residual lesion revascularization with a 0.014″ or a 0.018″ guidewire (e.g. glidewire Advantage (Terumo, Tokyo, Japan); V-18 (Boston Scientific, Marlborough, USA); Pilot 200 (Abbott Vascular, Santa Clara, USA)) followed by PTA with a 3 × 100 mm balloon in the side branches and a 5 × 40 mm balloon more proximal can be done. For remaining stenotic or occluded lesions in the main stem of the SMA stent placement is indicated, using either self-expandable stents(Carotid Wallstent, Boston Scientific, Marlborough, USA or SMART flex stent Cordis, Cordis, a Johnson & Johnson company, New Brunswick, USA), or ballloon- expandable stents (7 or 8 mm Palmaz Genesis, Cordis, a Johnson & Johnson company, New Brunswick, USA).
In case 1 we had to deal with a short remaining lesion in a quite large diameter vessel, therefore we chose a balloon expandable 8 × 24 mm stent.
Therapeutic options discussed here are applicable for AMI with thromboembolic occlusion of arteries, not caused by venous occlusion and non-occlusive mesenteric ischemia (NOMI).
There are no specific findings in physical examination or laboratory tests to confirm AMI. For decades the diagnostic process has been guided by imaging, which may facilitate a specific diagnosis but can also exclude other diseases. Non-contrast and biphasic (arterial and portal venous phase) contrast-material enhanced computed tomography with multi plane reconstructions has a high diagnostic sensitivity and specificity in AMI. CT findings in AMI include SMA occlusion, bowel wall thickening and decreased wall enhancement, bowel loop dilatation, mesenteric fat stranding and pneumatosis with or without portal gas. Diagnostic accuracy of imaging surpasses laboratory tests (D-dimer, Lactate and leukocytosis) and other diagnostic tools (Ginsburg, 2018; Kanasaki et al., 2018; Menke, 2010).
Until recently AMI and signs of non-viable bowel loops on CT were followed by laparotomy and bowel loop resection. Laparotomy may still be indicated but it is recently recommended that any bowel surgery should be preceded by revascularization (Ehlert, 2018). Revascularization can be performed by endovascular or open techniques. Open revascularization options include embolectomy with a balloon-tipped catheter through a distal transverse arteriotomy, and retrograde recanalization followed by antegrade stenting over a through and through wire (Acosta & Björck, 2014; Ehlert, 2018).
Endovascular approach (by brachial or groin access) should be preferred, given the possibilities to revascularize both the main trunk and side branches and the better reported results in the literature compared with open surgery.
Arthurs, in a retrospective single-center cohort study compared results of endovascular treatments vs. traditional operative therapy and reported a lower laparotomy rate (69% vs. 100%) and shorter length of resected bowel segments (52 cm vs. 160 cm) (Arthurs et al., 2011).
These trends are confirmed by Beaulieu et al., who reported on the National Inpatient Sample Database admissions from 2005 to 2009 and observed a lower mortality in endovascular vs. open treated patients (24.9 vs. 39.3%) and a lower bowel resection rate (14.4% vs. 33.4%) (Beaulieu, 2014).
Although these results indicate better clinical outcome after endovascular treatment, bias may have been introduced by selecting the clinical most fit patients for endovascular treatment and those with more advanced disease for open surgery.