Golzarian et al have done a nice job in reviewing mesenteric artery stenting for chronic mesenteric ischemia (CMI), and have noted it to be a rare disorder, with an incidence of 1 in 100,000. This statistic may be true, but it brings back memories of the “rare” incidence of renal artery stenosis (RAS) of 1% that I was taught 30 years ago while in medical school. We now know that RAS is one of the most common diseases treated by endovascular stenting. I suspect CMI will become analogous to RAS in regards to enhanced awareness, diagnosis, and treatment, especially with the recent improvements in endovascular devices and rapid emergence and adoption of multislice CTA. I predict we are now embarking upon an era in which CMI is about to get a great deal of “respect” from our vascular and interventional community.
Since its inception in 1918, “abdominal angina” or <a href="http://www.reactivehypoglycemia.net/postprandial-hypoglycemia.html" style="color:#000000; text-decoration:none; cursor:crosshair;">postprandial</a> pain has been classically characterized, but now many nonspecific symptoms are being associated with CMI, including an incidence of ischemic gastropathy of 20–25%.<sup>1,2</sup> The natural history of CMI remains poorly characterized. Kolkman et al reported that 34% of 110 CMI patients progressed to acute mesenteric ischemia (AMI), with the highest incidence in those patients with multivessel disease.<sup>2</sup> Thomas et al followed 980 patients who had asymptomatic CMI diagnosed by angiography for aortoiliac artery disease.<sup>3</sup> At 2.6-year follow-up, 27% had progressed to AMI, especially if disease was found in all three mesenteric vessels. It is likely that most patients with AMI have prior symptomatic, yet undiagnosed, and therefore, untreated CMI. It is my strong suspicion that CMI is much more common than clinically reported, remains largely misdiagnosed, and is a significant source of mortality and morbidity.
In our experience, CMI patients are associated with bilateral RAS, aortoiliac occlusive disease (AIOD), females, small body sizes, heavy smokers, the “hypoplastic aortic syndrome,” and the “mid-aortic syndrome”. Classic postprandial abdominal pain is pathonomic in the appropriate clinical setting, but this tends not to be the common presentation. Atypical abdominal pain, unexplained weight loss, negative gastrointestinal cancer workup, anemia, diffuse gastric gastritis, or colitis by endoscopy and non-specific symptoms of ischemic gastropathy is becoming a more common symptomatic presentation. Multislice CTA has now become our diagnostic tool of choice for patients with a suspicion of CMI. A full abdominal CTA with runoff for AIOD will obtain images starting above the celiac trunk, therefore, identifying a large pool of asymptomatic and symptomatic CMI patients who will potentially be candidates for PTA/stenting.
The authors have appropriately noted the median arcuate ligament syndrome and identified the important techniques and technical considerations for mesenteric PTA/stenting. Much like RAS, CMI lesions are usually ostial, associated with calcifications, and should be treated with PTA/stenting with balloon expandable stents. In 2004, AbuRahma et al performed a comprehensive literature meta analysis of PTA/stenting in CMI patients identifying 241 reported cases. This analysis has been updated by the authors, but it still appears there are less than 500 reported mesenteric artery PTA/stent cases.<sup>4</sup> As suggested by the authors, it appears mesenteric PTA/stenting is associated with a high initial procedural and clinical success, low complications, and adequate medium-term clinical success, with a clinical patency rate of 60–70% at 2–3 years. Instent restenosis (ISR) rates are generally reported at between 10–20% at 24 months.
We have just completed a 6-year analysis of 99 CMI vessels treated with PTA/stenting and a 2-year analysis on the role of CTA in the diagnosis and follow-up of 48 patients.<sup>5</sup> Our analysis was consistent with the authors metanalysis of the literature, with a procedural success rate of 97.9%, clinical success of 91%, a low complication rate (1.8%), and ISR rate of 19% at 24 months. We found that CTA was an extremely accurate noninvasive imaging modality for the diagnosis of CMI and facilitated the overall management and follow up of CMI patients treated with PTA/stenting (Figures 1A–C).
In conclusion, CMI largely remains an unappreciated and underdiagnosed disease. With the advent of multislice CTA, refined endovascular tools and now accumulating data supporting mesenteric artery PTA/stenting, hopefully this next decade will be a decade in which CMI gets the “endovascular respect” it deserves, analogous to the treatment and “respect” given to RAS over the previous 10 years.