Abstract
The current guideline published in the United European Gastroenterology Journal provides an ample summary of the current evidence and multidisciplinary expert recommendations on relevant points regarding diagnosis and treatment of chronic mesenteric ischemia (CMI). 1 The guidelines focus on new developments relevant for CMI. The information is combined with the expert panels’ opinions, and the end result is a specific set of practice guidelines intended to influence physicians and patients. Hence, there is something for everyone.
Depending on physician confidence and preference (gastroenterologist vs surgeon), the variety of recommendations could be used to diagnose CMI and its specific characteristics. Computed tomography angiography (CTA) or contrast enhanced magnetic resonance angiography (CE-MRA) have replaced conventional angiography for patients suspected of having CMI. The current European guidelines address this issue, assigning limiting diagnostic value of functional testing in patients with suspected CMI. To make it simple, high index of suspicion for CMI requires CTA with 100% sensitivity. On the other hand, exclusion of other etiologies by imaging of the upper abdomen for gallstones and pancreatitis and upper endoscopy in patients suspected of CMI is important to prevent overtreatment. Only when an occlusive etiology of CMI is established in the multidisciplinary meeting, are patients planned for revascularization therapy. 2
An available risk assessment chart is a useful tool in clinical practice to stratify CMI-suspected patients into three groups: 3 (1) wait-and-see policy justified, (2) additional testing indicated, and (3) immediate vascular intervention warranted.
If not treated, CMI leads to deterioration and ultimately to death. The 5-year mortality in asymptomatic patients with CMI is up to 40%; if all three main visceral arteries are affected it is up to 86%. 4
The current review confirms that the majority of physicians applies an endovascular first (EV) approach, which is associated with lower rates of major complications, lower costs, and shorter length of stay compared with surgery. However, is this conclusion convincing enough for the adoption of an EV treatment strategy? The results of large databases should be interpreted with caution. Apart from the different mechanisms leading to CMI, 5 cohorts undergoing endovascular and open surgical repair are not always comparable. In fact, most studies lack risk stratification between CMI patients. 6
The current study group points out that superior mesenteric artery (SMA) should be a main vessel to target the intervention in case of multiple vessel disease. In addition, the incidence of recurrent symptoms or reinterventions in two-vessel stenting was not different from SMA-only stenting. 7
Similar to the widespread adoption of endovascular aortic aneurysm repair, EV treatment of CMI has created a new set of challenges. Difficult vascular access, restenosis, and stent occlusion are all factors that must be considered carefully. Follow-up details are not available, especially for EV patients, and the real rate of long-term stent patency is probably far from good. Moreover, occlusion of the stented artery puts patient at risk of life-threatening acute mesenteric events. These guidelines highlight the importance of close follow up and specific focus on the potential for restenosis in patients with CMI who undergo endovascular treatment.
Other than atherosclerosis, some uncommon conditions can cause CMI. Median arcuate ligament syndrome (MALS) is a very rare and difficult diagnosis. The patient’s diagnostic work up, often coordinated by gastroenterologists or family physician, can cause two cognitive errors. First, the ‘availability heuristic’, a mental shortcut that leads to fast, but sometimes incorrect, assessments. 8 Clinicians’ regular experience with intra-luminal etiologies such as inflammatory bowel disease, rather than vascular pathology in young patients, bias initial investigations. Second, an ‘ascertainment bias’, whereby clinicians investigate for common conditions (such as peptic disease) that they hoped to find due to their familiarity with subsequent treatment. 9 MALS is not a vascular disease, thus EV interventions would not work. The same is true for other rare causes of CMI, including vasculitis and fibromuscular dysplasia. The European CMI study group was unable to make evidence-based recommendations, but gives valuable expert opinion.
Patients in need of immediate treatment may benefit from the enhanced recovery after surgery (ERAS) program. The key principles of the ERAS protocol include pre-operative counseling, preoperative nutrition [including total parenteral nutrition (TPN) if needed], standardized anesthetic and analgesic regimens (epidural and non-opiod analgesia), and early mobilization. 10
Since they propose a practical approach and have been developed by a multidisciplinary team, many aspects of guidelines lack the high evidence of recommendations. Taken together, the three papers cited should be considered as European consensus documents since they provide state-of-the-art information, are wherever possible evidence based, and have been developed via a scientific process.1–3
