In this review we will cover the current insights in splanchnic or gastrointestinal ischemia. This disorder is still rarely seen in daily practice, and randomized controlled trials are absent, therefore the view of this paper is highly personal and partly authority-based in its conclusions. The spectrum of ischemic bowel disease is broad, ranging from transient left-sided ischemic colitis (with a good prognosis) to full blown intestinal infarction, with a high death rate. We will focus on new developments in clinical presentation, diagnostic approaches, and treatment options. Splanchnic ischemia can develop during low-flow states in patients with patent vessels, and in subjects with varying degree of splanchnic artery stenoses or splanchnic venous thrombosis. The prevalence of significant splanchnic arterial stenoses, or chronic splanchnic disease (CSD) is high, ranging from 30% to 50%[1,2
]. Chronic splanchnic syndrome (CSS) occurs when ischemic symptoms develop. The most characteristic ischemic symptoms consist of postprandial pain, with resultant fear of eating and weight loss. When epigastric bruit is included, these are the so-called classical triad of CSS. In most patients with CSS, this triad is incomplete. The true incidence of CSS is currently unclear, but is rare compared to CSD due to abundant collateral circulation.
Two important developments occurred in the last decade. Firstly, validation of the gastric exercise tonometry, which is currently the only clinically available and validated diagnostic test to ascertain the presence of splanchnic ischemia[3,4
]. Using an ischemia-specific test it should be possible (1) to identify patients with symptomatic vessel stenoses, or CSS, which can be treated, and (2) to make this diagnosis in time and thus prevent the disaster of acute intestinal infarction. Secondly, the increasing evidence that one vessel CSD may cause splanchnic ischemia resulting in one vessel CSS, and can be successfully treated with appropriate selection procedures[5
]. An important difference in presentation, treatment and outcome has been shown to exist between single and multi-vessel disease[6
]. In the latter group, the clinical presentation is often less typical, with diarrhea, unexplained gastric ulcers, or dyspepsia-like symptoms. These insights stem mainly from our work with tonometry.
An entirely different entity consists of patients suffering from splanchnic ischemia without splanchnic stenoses; the so-called non-occlusive mesenteric ischemia (NOMI). It can be seen as a consequence of physiological adaptation mechanisms during low-flow states were blood is dispersed from the gastrointestinal region to more vital organs[7
]. This situation is very common in intensive care and operative units, but can also be seen in outpatients. Treatment consists of aggressive fluid resuscitation and medication. However, bowel infarction can still occur.
In the last decade a change in imaging of the splanchnic vessels occurred. Duplex ultrasound, although operator dependent and suitable for 80% of patients, is still the first choice. Visceral angiography has increasingly been replaced by CT and MR-based angiographic reconstruction techniques. The clinically important advantages and disadvantages of these techniques will be discussed. Whichever technique is used, it leaves the clinician with only anatomical information. To decide whether a given stenosis has caused the symptoms, information on actual ischemia is required. This information can be obtained using tonometry, which has a proven accuracy of 80%-90%. Other tests including, serological iFABP, endothelial progenitor cell measurement, or MR angiography (MRA)-based saturation measurements, may serve that purpose in the near future.
Treatment options have changed considerably over the last decade. Apart from the classical transabdominal vascular reconstructive surgery techniques, minimally invasive endoscopic treatment of the celiac axis comp-ression syndrome, endovascular antegrade stenting, or laparotomy-assisted retrograde endovascular recanali-zation and stenting have broadened our therapeutic “armory” considerably. The main patient characteristics to guide therapy choice, which include anatomical considerations, as well as body weight, co-morbidity and severity of ischemia, will be discussed.