Spontaneous isolated celiac trunk and superior mesenteric artery (SMA) dissection is a rare medical condition with an incidence of 0.08% [1]. Symptoms associated with isolated SMA dissection vary from asymptomatic to severe cases, such as acute abdominal pain with bowel ischemia or peritonitis. Treatment largely depends on the severity of the clinical presentation and can vary from conservative follow-up to surgical repair, including vascular bypass operation and bowel resection. In patients with moderate symptoms of intestinal ischemia without signs of bowel necrosis, endovascular stent placement has been performed successfully. This case report presents a patient with acute abdominal pain with an isolated SMA dissection associated with severe true lumen stenosis and a thrombosed false lumen with an ulcer-like projection (ULP) on contrast-enhanced computed tomography. Definitive treatment was performed by placing a coronary covered stent to reopen the true lumen and exclude the ULP in the false lumen. Institutional Review Board approval was waived due to the retrospective case report. Informed consent has been obtained from the patient for publication of this case report.

A 51-year-old male presented to the emergency department with sudden onset of postprandial abdominal pain 12 hours prior. The pain persisted, and the patient did not respond to self-administered pain medications, including paracetamol. The patient had a medical history of ulcerative colitis that was successfully treated with vedolizumab. Further clinical examinations revealed unremarkable results. Triphasic computed tomography angiography (CTA) revealed isolated dissection of the main branch of the SMA, extending into multiple side branches, and thrombosis of the false lumen, with ULP (Fig. 1). In addition, the true lumen was severely narrowed due to compression from the thrombosed false lumen.

Figure 1. Preinterventional sagittal reconstruction arterial-phase CTA revealed focal postostial stenosis of the superior mesenteric artery main branch (arrow), distal to the ulcer-like false lumen opacification (arrowheads). CTA, computed tomography angiography.

After a multidisciplinary discussion between interventional radiology and vascular surgery, it was decided to treat the isolated dissection with an endovascular approach, 24 hours after the onset of pain symptoms.

Radial access was preferred over femoral access for cannulation of the SMA because of the sharp aortomesenteric angle observed on sagittal CT reconstruction images.

After local administration of anesthetics, a 6 French (F) radial sheath (Elite, Galt Medical Corp.) was placed into the left radial artery under ultrasound guidance. A 6F hockey stick guiding catheter (Launcher, Medtronic) was then advanced into the ostium of the SMA. Selective contrast injection confirmed severe narrowing of the proximal SMA main branch and thrombosed false lumen with an ULP (Fig. 2A). Two covered, balloon-expandable stents, both 5 mm in diameter and 16 mm and 24 mm in length (BeGraft Coronary, Bentley InnoMed), were placed in the proximal SMA with complete coverage of the stenosis and vessel wall defect. The stents were post-dilated to a diameter of 6 mm (Ultra-Soft SV^TM balloon, Boston Scientific). Completion selective angiography of the SMA after stent placement showed re-expansion of the stented segment of the SMA with mild residual narrowing distal to the stent related to a stent-induced spasm (Fig. 2B).

Figure 2. (A) A selective angiography was performed prior to stenting. Selective angiography of the superior mesenteric artery confirmed the postostial stenosis of the main branch (arrow), distal to the ulcer-like false lumen opacification (arrowheads). (B) A selective angiography was performed after stenting. Selective angiography after covered stent placement (arrowheads) revealed fully patent superior mesenteric main branch and mild vascular spasm at the distal end of the covered stent (arrow).

The patient immediately reported improvement in abdominal pain, and a control CT performed the next day showed no residual filling of the vessel wall defect, improved patency of the true lumen, and complete thrombosis of the false lumen. The patient was further treated with dual antiplatelet therapy, including lifelong aspirin 81 mg and clopidogrel 75 mg for 2 months and was discharged 2 days later. Clinically, no recurrent symptoms of mesenteric ischemia occurred, and a follow-up CTA performed 13 months after the index procedure showed the patent covered stent and complete disappearance of the false lumen of the SMA (Fig. 3).

Figure 3. A follow-up CTA was performed. Reconstructed sagittal three-dimensional images of the CTA, 13 months after stenting procedure demonstrated the fully patent stent (arrowheads) without any opacification of a residual false lumen. CTA, computed tomography angiography.

Spontaneous isolated SMA dissection is a rare pathology that often presents as acute abdominal pain with or without bowel ischemia. In some cases, it can be an asymptomatic incidental finding on abdominal imaging studies [1]. In most patients, the entry defect is located 2-3 cm distal to the SMA ostium. A possible etiological factor for isolated SMA dissection may be the higher shear stress on the vessel wall related to the transition from the fixed retropancreatic portion to the more mobile mesenteric portion of the SMA [2,3].

A classification system for isolated SMA dissection was proposed by Sakamoto et al. [4] in 2007, categorizing dissections according to the patency and defects in the vessel wall: a patent false lumen with (type 1) and without a re-entry defect (type 2), a thrombosed false lumen with one or two ULPs (type 3), or without ULPs (type 4). According to Sakamoto et al. [4], this case corresponds to type 3.

Although digital subtraction angiography (DSA) is the standard tool to guide the endovascular procedure, CTA has become the preferred non-invasive imaging modality for the diagnosis of isolated SMA due to its high performance in evaluating the degree of luminal narrowing and depicting the entry point of the dissection, and it is more accurate than DSA in depicting the thrombosed false lumen and branch vessel involvement [5].

The type of treatment depends on the clinical symptoms and includes conservative management in asymptomatic patients and open surgery in patients with extensive bowel ischemia. In the present case, there was no clinical, radiological, or biochemical evidence of bowel ischemia; however, given the persistence of pain symptoms and significant stenosis of the true lumen, endovascular stenting of the entry defect with a covered stent was deemed appropriate. A covered stent was chosen in the present case for the following reasons: first, it allows immediate exclusion of the focal ULP protruding into the false lumen of the SMA; second, covered stents may induce less late intimal hyperplasia than bare metal stents, as seen in fenestrated and branched aortic endovascular repair [6]. Finally, a multicenter randomized controlled trial comparing covered stents with bare metal stents for endovascular treatment of chronic mesenteric ischemia demonstrated superior primary patency rates for covered stents (81% vs. 49%) at 24 months of follow-up [7].

In this case, a coronary covered stent mounted on a 0.014-inch monorail system was preferred over an over-the-wire 0.035 inch peripheral covered stent [8] because of the smoother navigation of coronary stents into small visceral arteries, thereby avoiding potential catheter-induced spasm and intimal vessel wall dissection. Although coronary (covered) stents are considered “off-label” for peripheral use, local reimbursement organizations accept these devices for peripheral use.

In conclusion, this report illustrates the successful treatment of a rare case of symptomatic isolated SMA dissection using coronary covered stent, resulting in re-expansion of the narrowed true lumen and complete exclusion of the false lumen.

None.

The authors has nothing to disclose.

Concept and design: all authors. Analysis and interpretation: all authors. Data collection: all authors. Writing the article: all authors. Critical revision of the article: all authors. Final approval of the article: all authors. Obtained funding: none. Overall responsibility: all authors.