Contemporary population-based studies on the epidemiology of this disease entity are lacking. According to a Swedish study based on autopsy and operating room data, the incidence of AMI in the city of Malmo was 12.9/100,000 person-years. More than two third of the cases had thromboembolic etiology, while the remainder was venous occlusions or non-occlusive mesenteric ischemia [21]. Clinical risk factors include atrial fibrillation, recent myocardial infarction, congestive heart failure and peripheral arterial emboli [22]. Up to 40 % of patient with acute mesenteric ischemia have a history of post-prandial abdominal pain in the past, suggesting an acute-on-chronic process [23].

Common manifestations of AMI include abdominal pain, nausea and vomiting. Unless transmural bowel involvement is present, there may be minimal tenderness to palpation upon initial presentation. Unfortunately, these symptoms overlap with several other intra-abdominal pathologies and commonly lead to a delay in diagnosis or misdiagnosis. This diagnostic challenge is one of the main reasons why mortality from acute mesenteric ischemia has remained 50–70 % over the years [19, 21, 24]. Therefore, physicians need to maintain a high index of suspicion. Once suspected, a multi-detector row computed tomography angiography (MDCTA) forms the cornerstone of the diagnostic algorithm [25–28]. It provides excellent visualization of the celiac artery and the SMA and aids in excluding other causes of abdominal pain. Furthermore, it allows for assessment of bowel wall thickness, pneumatosis, mucosal, and bowel wall enhancement pattern that support the diagnosis of AMI. There is no single radiographic finding that is perfectly sensitive or specific, but using a combination of CT criteria achieves a positive and negative predictive value of 100 % and 96 % respectively [29].

Once suspected, treatment is divided into three aspects; appropriate resuscitation, prompt restoration of blood flow and resection of non-viable bowel. Resuscitation usually involves isotonic crystalloid fluids. Various clinical parameters are used as objective evidence of adequate resuscitation, including mentation, heart rate, blood pressure, urine output and degree of metabolic acidosis. AMI is a surgical problem, however and resuscitation should not delay revascularization and abdominal exploration, if needed. Based on the pre-operative CT and clinical exam, it can be determined whether the patient has peritonitis or not, and whether the occlusion is embolic or thrombotic in nature. Presence of peritonitis necessitates laparotomy to assess bowel viability and need for resection. Grossly necrotic bowel is resected. The bowel ends may be stapled off and anastomosis or stoma formation performed at a second-look laparotomy.

Mesenteric revascularization in the acute setting is typically focused on the SMA only and precedes bowel resection in order to minimize the length of intestine removed. Revascularization may take one of three forms depending on the etiology of the occlusion, suspicion for bowel infarction and available resources:

The SMA can be approached percutaneously via femoral or brachial artery. Brachial approach is preferred if there is a sharp downward angle between the SMA and the aorta. If percutaneous access fails, the SMA can be accessed in an open, retrograde fashion by exposing it at the base of the mesocolon. Once access is established, there are different endovascular options to treat an SMA occlusion:

This is a viable option in patients without any need for bowel resection. Briefly, over a stiff 0.035-in. wire, a 7-Fr sheath with a removable hub is placed proximal to the embolus. A hydrophilic 0.035-in. guidewire is then passed through the embolus. Over this wire, the tip of a 6-Fr guiding catheter is passed through the embolus. After removing the guidewire, a 20-ml syringe aspiration is applied manually to the guiding catheter accompanied with catheter withdrawal. Several passes are usually required. A small series out of Sweden reported 9 cases of percutaneous aspiration embolectomy of the SMA [7]. Technical success (defined as restoration of SMA blood flow) was achieved in all 7, however all patients had residual embolus in at least one branch of SMA upon completion. There was one case of SMA dissection, treated with stent. One patient went on to require bowel resection. In-hospital mortality was 10 %. Another small series from Germany reported 6 cases of percutaneous aspiration embolectomy [8]. SMA blood flow was restored to normal in 5, while 1 patient had diminished blood flow upon completion due to a dissection. In-hospital mortality was 33 %.

In cases of incomplete aspiration embolectomy or distal embolization, percutaneous SMA thrombolysis is an option in patients without peritonitis or high risk of bleeding. With the sheath placed in proximal SMA, a multiple side-hole infusion catheter or a microcatheter is advanced in the embolus and a thrombolytic agent infused, with repeat angiography at 12–24 h interval. A paper from the Swedvasc registry reported cases of percutaneous thrombolysis for acute SMA occlusions [9]. Between 1987 and 2009, 34 patients underwent this intervention. No one had peritonitis. Notably, 47 % of patients underwent an adjunctive endovascular procedure at the time of thrombolysis (aspiration embolectomy, angioplasty/stenting, mechanical thrombectomy, papaverine infusion). Complete or partial lysis was achieved in 30 patients (88 %). Six bleeding complications were noted, which were all self-limiting. In-hospital mortality was 26 %. Successful thrombolysis was associated with decreased mortality.

This allows treatment of underlying stenotic or occlusive lesions primarily or after thrombolysis. For ostial or heavily calcified lesions, balloon-expandable stents are preferred over self-expanding ones owing to their superior radial force. A completion angiography is performed after stent placement, as well as pressure measurement. If the residual pressure gradients across the lesion/stent exceeds 10 mmHg, additional angioplasty and/or stenting is performed.

This “hybrid” approach was first described by Milner et al. in 2004 and has since been described by various groups in North America and Europe [11–20]. Variations in the technique have been described but in general, the SMA is punctured anteriorly with a micropuncture needle and 0.018” wire. The inner cannula of the micropuncture set can be used instead of a sheath. Lateral fluoroscopy is used to advance the wire to the level of the obstruction. Retrograde arteriography is performed. A torque device and minimal shaping of the wire is the default, trying to maintain luminal position of the wire. A guiding catheter may also provide some necessary support and steerablity. Once the lesion is crossed and aortic access is obtained, the arteriotomy is made to include the wire, with the wire left in place. The arteriotomy should be kept as proximal on the SMA as possible. The artery is carefully inspected. Occasionally there is thrombus in the proximal SMA that can be retrieved with a clamp. A limited endarterectomy is performed and a patch angioplasty is performed with either vein or bovine pericardium. Prior to completion of the patch a 6 or 7 Fr sheath is advanced over the wire in through the side of the arteriotomy. The sutures are secured with a rubber shod while the artery is stented. Usually a 3–4 mm predilation is performed with repeat retrograde contrast injection to identify the SMA origin. If visualization of the SMA origin or aorta remains poor, a femoral puncture can be used to place a flush catheter in the aorta for imaging purposes. Most often a 6 or 7 mm balloon expandable stent or stentgraft is required. This approach allows the surgeon to evaluate the bowel and intervene on the vasculature at the same time. Furthermore, in case of bowel perforation, it avoids the use of a prosthetic bypass in a contaminated operative field. The largest case series on retrograde open mesenteric stenting comes from a Dutch group, published in 2014 [20]. They analyzed 68 patients with AMI presenting between 2007 and 2011. In this report, percutaneous mesenteric artery stenting was the preferred treatment in patients without peritonitis, while retrograde open mesenteric stenting (ROMS) was reserved for cases of percutaneous technical failure. Technical difficulty, including the inability to cross the lesion with a wire, was the most common reason for failure of percutaneous revascularization. Fifty of these patients were able to undergo percutaneous mesenteric artery stenting, while 15 required retrograde stenting. Technical success (defined as successful completion of the procedure and <30 % residual stenosis) was achieved in 14 of 15 patients despite the preceding percutaneous failure. One patient underwent bowel resection despite successful revascularization. Two patients had progression of bowel ischemia and required a second laparotomy and bowel resection. The mortality rate in ROMS group at 30 days was 20 % and primary stent patency (defined as uninterrupted patency) was 91 %. At 12 months, mortality rate for ROMS patients was still 20 %, while primary stent patency was 83 %. Primary assisted patency (defined as revision of the revascularization method to prevent impending occlusion) was 91 % while secondary patency (defined as restored patency after occlusion by thrombectomy or angioplasty) was 100 %. Unfortunately, patient outcomes in the percutaneous stenting group were not reported in this study.