Acute embolic mesenteric ischemia treated by complex endovascular stent-based angioplasty

Acute mesenteric ischemia (AMI) is associated with a very high mortality rate if it is not rapidly diagnosed and treated [1]. Treatment of arterial occlusive AMI has historically involved primary surgical exploration, revascularisation, and resection of infarcted bowel. However, recent reports suggests that endovascular revascularisation is associated with very high procedural success and relatively favourable outcomes as compared with a more traditional open approach [2].

We report the case of a 66-year-old male patient admitted for left lower leg pain for two days and abdominal pain for four hours. The patient's past history included a non-ST segment elevation myocardial infarction two weeks prior with conservative treatment, paroxysmal atrial fibrillation with poorly controlled anticoagulant therapy, stage III hypertension, and type 2 diabetes mellitus. Clinical examination showed a pale left lower leg with absent distal pulses, diffuse abdominal pain at palpation without sign of peritoneal irritation, hypotension (systolic blood pressure = 90 mmHg), and tachycardia with irregular rhythm (heart rate = 110 bpmin). Blood tests showed an increased level of lactic acid (5 mmol/l) and troponin I (1.5 ng/ml) and an INR value of 1.3. The electrocardiogram revealed atrial fibrillation with ST segment depression of 1 mm in V1 to V6. Transesophageal echocardiogram found a moderate left ventricle systolic dysfunction (left ventricle ejection fraction = 30–35%), anterior and lateral wall akinesia, and mild mitral regurgitation, with thrombus in the left atrial appendage. At this moment the suspicion of acute embolic lower left limb ischemia and acute embolic mesenteric ischemia was raised, probably from a cardiac source. An abdominal and pelvic computer tomography (CT) scan was made, which showed occlusion of the superior mesenteric artery (SMA) 5 cm from its origin with multiple atheromatous plaques without sign of bowel ischemia or occlusion of the left external iliac artery.

The initial therapy included fluid resuscitation, nasogastric tube decompression, anticoagulation, and avoidance of vasoconstricting agents and broad-spectrum antibiotics.

Because of the two simultaneous ischemic territories (abdominal and lower limb), we decided to adopt an interventional approach due to the complexity of the surgical approach, making a general surgeon and a vascular surgeon necessary. The patient was transferred to the cath lab. We used a right femoral approach, and a 7 French femoral sheath was introduced. The diagnostic angiography confirmed the embolic occlusion of the superior mesenteric artery and left external iliac artery seen on the CT (Figures 1, 2). The coronary angiography was done to assess the patency of coronary arteries and estimate the eventual surgical risk. It showed severe left main stem and multivessel disease (Figure 3). A 4.0 judkins right 7 French guiding catheter was used to engage the ostium of the SMA. The occlusion was passed using a 0.014” hydrophilic guidewire to the left branch of SMA. Repeated thrombaspiration was done with the extraction of a high amount of thrombus with a slight repermeabilisation of the SMA (Figure 4). Because of the lack of a longer stent, a 4.5 × 24 mm and two 4.0 × 24 mm bare metal stents were implanted in the SMA's left branch, with good result. The ileocolic trunk was visible by retrograde filling through collaterals from the left branch of the SMA. A second 0,014” hydrophilic guidewire was passed through the stent struts into the ileocolic artery (Figure 5). Repeated thrombaspiration was made and a 3.5 × 26 mm bare metal stent was implanted by the provisional T stenting technique. A postdilatation kissing balloons was done with a good angiographic final result, including the repermeabilisation of the entire SMA with good flow (Figure 6).

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Figure 5

Figure 6

Then, the patient was transferred to the surgical room, intubated, and mechanically ventilated. A left external iliac artery thromboembolectomy using the Fogarty catheter was performed with the repermeabilisation of the artery and distal peripheral pulse.

After an initial good clinical course, the patient deteriorated; he became hypotensive with the need of inotrope and vasopressors agents (dobutamine, noradrenaline), his lactic acid increased to 17 mmol/l, and he developed acute renal failure (creatinine level 1,9 mg/dl). A laparotomy was performed that showed signs of bowel infarction treated by right hemicolectomy, partial enterectomy, and ileostomy. After surgery the patient developed systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome with progressive hypotension, bradycardia, and asystole that was nonresponsive to the resuscitation manoeuvres.

The mortality rate in AMI is overall greater than 50%. Prompt diagnosis and institution of revascularisation therapy are crucial for a successful outcome [3, 4].

Embolisation of thrombus into the mesenteric arterial circulation accounts for 40–50% of the cases of AMI [5]. Other causes of AMI are: acute thrombosis superimposed on a chronic atherosclerotic lesion (25%), aortic dissection involving the SMA (<5%), and nonocclusive mesenteric ischemia that results from a prolonged state of hypotension (25%) [6, 7]. The most common aetiology for mesenteric arterial embolisation is from a cardiac source. Atrial fibrillation or prior myocardial infarction is commonly observed [8]. Approximately 20% of individuals presenting with mesenteric arterial embolisation from a cardiac source also have a peripheral arterial embolus [5].

In our case, the patient presented with embolic AMI and acute limb ischemia due to poorly anticoagulated atrial fibrillation. The clinical scenario was aggravated by the severe multivessel coronary artery disease and left main stem stenosis, which gives a high surgical risk for noncardiac surgery. Because of this high surgical risk, we used a minimally invasive strategy to resolve both ischemic territories.

In the US registry study of 5237 patients treated for AMI, the outcomes of patients who were treated with endovascular intervention were compared to those who were treated surgery [1]. Patients enrolled in the endovascular treatment group had higher rates of cardiovascular comorbidities than those included in the surgical treatment group, including hypertension, peripheral vascular disease, coronary artery disease, and chronic renal failure. Despite these unfavourable patient characteristics, mortality was significantly lower in the endovascular group compared with the surgical group (16% vs 39%, p < 0.001). Similar results came from the study conducted by Arthurs et al. on 70 patients with AMI [9].

In this case, the multiple stents-based angioplasty and the provisional T stenting technique was used due to the diffuse damaged SMA with the aim to revascularise all its branches. There are very few case report of this technique of revascularisation in the literature, mostly confined to the celiac artery disease [10, 11].

After the revascularisation of the SMA and external iliac artery, the patient developed SIRS, which can be expected because of the two large ischemic territories which were revascularised (splahnic and lower limb).

The initial bowel hypoxic ischemic injury can be augmented by the subsequent reperfusion injury after reestablishment of forward flow. Oxygen radicals and the activation of phospholipase A2 during reperfusion seem to be instrumental for the development of haemorrhagic mucosal lesions after intestinal ischemia [12]. We cannot exclude the contribution of the reperfusion syndrome to the post procedural bowel injury that needed laparotomy with enterectomy.

Because of the bowel necrotic ischemic lesions, septic shock can complicate the clinical course. Despite the intensive critical care treatment, including broad-spectrum antibiotics, the patient became hypotensive under high doses of inotropic and vasopressor agents and died.

The endovascular therapy for embolic AMI showed great efficacy even in technically demanding interventions, and it can become an alternative to surgery, particularly in patients with a high surgical risk. Complex stenting techniques can be used for diffuse affected SMA with good angiographic result, although there are few case reports of complex angioplasty performed for the occlusion of SMA.

Patient with AMI are very fragile patients that need intensive care treatment and a multidisciplinary approach.