- This article concerns ischemia of the small bowel. See ischemic colitis for ischemia of the large bowel
|Classification and external resources|
Mesenteric ischemia, also known as mesenteric vascular disease, is a medical condition in which injury of the small intestine occurs due to not enough blood supply. It can come on suddenly, known as acute mesenteric ischemia, or gradually, known as chronic mesenteric ischemia. Acute disease often presents with sudden severe pain. Symptoms may come on more slowly in those with acute on chronic disease. Signs and symptoms of chronic disease include abdominal pain after eating, unintentional weight loss, vomiting, and being afraid of eating.
Risk factors include atrial fibrillation, heart failure, chronic renal failure, being prone to forming blood clots, and previous myocardial infarction. There are four mechanisms by which poor blood flow occurs: a blood clot from elsewhere getting lodged in an artery, a new blood clot forming in an artery, a blood clot forming in the mesenteric vein, and insufficient blood flow due to low blood pressure or spasms of arteries. Chronic disease is a risk factor for acute disease. The best method of diagnosis is angiography, with computer tomography (CT) being used when that is not available.
Treatment of acute ischemia may include stenting or medications to break down the clot provided at the site of obstruction by interventional radiology. Open surgery may also be used to remove or bypass the obstruction and may be required to remove any intestines that may have died. If not rapidly treated outcomes are often poor. Among those affected even with treatment the risk of death is 70% to 90%. In those with chronic disease bypass surgery is the treatment of choice. Those who have thrombosis of the vein may be treated with anticoagulation such as heparin and warfarin, with surgery used if they do not improve.
Acute mesenteric ischemia affects about five per hundred thousand people per year in the developed world. Chronic mesenteric ischemia affects about one per hundred thousand people. Most people affected are over 60 years old. Rates are about equal in males and females of the same age. Mesenteric ischemia was first described in 1895.
Signs and symptoms
- A hyper active stage occurs first, in which the primary symptoms are severe abdominal pain and the passage of bloody stools. Many patients get better and do not progress beyond this phase.
- A paralytic phase can follow if ischemia continues; in this phase, the abdominal pain becomes more widespread, the belly becomes more tender to the touch, and bowel motility decreases, resulting in abdominal bloating, no further bloody stools, and absent bowel sounds on exam.
- Finally, a shock phase can develop as fluids start to leak through the damaged colon lining. This can result in shock and metabolic acidosis with dehydration, low blood pressure, rapid heart rate, and confusion. Patients who progress to this phase are often critically ill and require intensive care.
Case series report prevalence of clinical findings and provide the best available, yet biased, estimate of the sensitivity of clinical findings. In a series of 58 patients with mesenteric ischemia due to mixed causes:
- abdominal pain was present in 95% (median of 24 hours duration). The other three patients presented with shock and metabolic acidosis.
- nausea in 44%
- vomiting in 35%
- diarrhea in 35%
- heart rate > 100 in 33%
- 'blood per rectum' in 16% (not stated if this number also included occult blood - presumably not)
- constipation 7%
In the absence of adequate quantitative studies to guide diagnosis, various heuristics help guide diagnosis:
- Mesenteric ischemia "should be suspected when individuals, especially those at high risk for acute mesenteric ischemia, develop severe and persisting abdominal pain that is disproportionate to their abdominal findings"
- Regarding mesenteric arterial thrombosis or embolism: "...early symptoms are present and are relative mild in 50% of cases for three to four days before medical attention is sought".
- Regarding mesenteric arterial thrombosis or embolism: "Any patient with an arrhythmia such as atrial fibrillation who complains of abdominal pain is highly suspected of having embolization to the superior mesenteric artery until proved otherwise".
- Regarding nonocclusive intestinal ischemia: "Any patient who takes digitalis and diuretics and who complains of abdominal pain must be considered to have nonocclusive ischemia until proved otherwise".
It is difficult to diagnose mesenteric ischemia early. One must also differentiate ischemic colitis, which often resolves on its own, from the more immediately life-threatening condition of acute mesenteric ischemia of the small bowel.
In a series of 58 patients with mesenteric ischemia due to mixed causes:
- White blood cell count >10.5 in 98% (probably an overestimate as only tested in 81% of patients)
- Lactic acid elevated 91% (probably an overestimate as only tested in 57% of patients)
A number of devices have been used to assess the sufficiency of oxygen delivery to the colon. The earliest devices were based on tonometry, and required time to equilibrate and estimate the pHi, roughly an estimate of local CO2 levels. The first device approved by the U.S. FDA (in 2004) used visible light spectroscopy to analyze capillary oxygen levels. Use during Aortic Aneurysm repair detected when colon oxygen levels fell below sustainable levels, allowing real-time repair. In several studies, specificity has been 83% for chronic mesenteric ischemia and 90% or higher for acute colonic ischemia, with a sensitivity of 71%-92%. This device must be placed using endoscopy, however.
- prevalence of mesenteric ischemia 23%
- sensitivity 64%
- specificity 92%
- positive predictive value (at prevalence of 23%) 79%
- negative predictive value (at prevalence of 23%) 95%
- prevalence of mesenteric ischemia 62%
- sensitivity 83%
- specificity 93%
- positive predictive value (at prevalence of 62%) 93%
- negative predictive value (at prevalence of 62%) 61%
Findings on CT scan include:
- Mesenteric edema
- Bowel dilatation
- Bowel wall thickening
- Intramural gas
- Mesenteric stranding
As the cause of the ischemia can be due to embolic or thrombotic occlusion of the mesenteric vessels or nonocclusive ichemia, the best way to differentiate between the etiologies is through the use of mesenteric angiography. Though it has serious risks, angiography provides the possibility of direct infusion of vasodilators in the setting of nonocclusive ischemia 
NG tube decompression, angiogram for diagnosis and treatment, heparin anticoagulation. Papaverine to decrease arterial vasospasm.
"Surgical revascularisation remains the treatment of choice for mesenteric ischaemia, but thrombolytic medical treatment and vascular interventional radiological techniques have a growing role".
If the ischemia has progressed to the point that the affected intestinal segments are not savable, a bowel resection of those segments is called for. Often, obviously dead segments are removed at the first operation, and a second-look operation is planned to assess segments that are borderline that may be savable after revascularization.
- venous thrombosis - 32% mortality
- arterial embolism - 54% mortality
- arterial thrombosis - 77% mortality
- non-occlusive ischemia - 73% mortality
In British English it is spelled mesenteric ischaemia.
- Yelon, Jay A. (2014). Geriatric Trauma and Critical Care (Aufl. 2014 ed.). New York: Springer Verlag. p. 182. ISBN 9781461485018.
- Bobadilla, JL (August 2013). "Mesenteric ischemia.". The Surgical clinics of North America 93 (4): 925–40, ix. doi:10.1016/j.suc.2013.04.002. PMID 23885938.
- Britt, L.D. (2012). Acute care surgery (1st ed.). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. p. 621. ISBN 9781608314287.
- Creager, Mark A. (2013). Vascular medicine : a companion to Braunwald's heart disease (2nd ed.). Philadelphia, PA: Elsevier/Saunders. pp. 323–324. ISBN 9781437729306.
- Sreenarasimhaiah, J (April 2005). "Chronic mesenteric ischemia.". Best practice & research. Clinical gastroenterology 19 (2): 283–95. doi:10.1016/j.bpg.2004.11.002. PMID 15833694.
- Liapis, C.D. (2007). Vascular surgery. Berlin: Springer. p. 420. ISBN 9783540309567.
- Geoffrey D. Rubin (2012). CT and MR Angiography: Comprehensive Vascular Assessment. Lippincott Williams & Wilkins. p. 318. ISBN 9781469801834.
- Gustavo S. Oderich (2014). Mesenteric Vascular Disease: Current Therapy. Springer. p. 105. ISBN 9781493918478.
- Boley, SJ, Brandt, LJ, Veith, FJ (1978). "Ischemic disorders of the intestines". Curr Probl Surg 15 (4): 1–85. doi:10.1016/S0011-3840(78)80018-5. PMID 365467.
- Hunter G, Guernsey J (1988). "Mesenteric ischemia". Med Clin North Am 72 (5): 1091–115. PMID 3045452.
- Oldenburg WA, Lau LL, Rodenberg TJ, Edmonds HJ, Burger CD (2004). "Acute mesenteric ischemia: a clinical review". Arch. Intern. Med. 164 (10): 1054–62. doi:10.1001/archinte.164.10.1054. PMID 15159262.
- Font VE, Hermann RE, Longworth DL (1989). "Chronic mesenteric venous thrombosis: difficult diagnosis and therapy". Cleveland Clinic journal of medicine 56 (8): 823–8. doi:10.3949/ccjm.56.8.823. PMID 2691119.
- Levy PJ, Krausz MM, Manny J (1990). "Acute mesenteric ischemia: improved results--a retrospective analysis of ninety-two patients". Surgery 107 (4): 372–80. PMID 2321134.
- Park WM, Gloviczki P, Cherry KJ, Hallett JW, Bower TC, Panneton JM, Schleck C, Ilstrup D, Harmsen WS, Noel AA (2002). "Contemporary management of acute mesenteric ischemia: Factors associated with survival". J. Vasc. Surg. 35 (3): 445–52. doi:10.1067/mva.2002.120373. PMID 11877691.
- "American Gastroenterological Association Medical Position Statement: guidelines on intestinal ischemia.". Gastroenterology 118 (5): 951–3. May 2000. doi:10.1016/s0016-5085(00)70182-x. PMID 10784595.
- Cope, Zachary; Silen, William (April 2005). Cope's Early Diagnosis of the Acute Abdomen (21st ed.). New York: Oxford University Press. ISBN 978-0-19-517545-5. LCCN 2004058138. OCLC 56324163.
- Evennett NJ, Petrov MS, Mittal A, Windsor JA (July 2009). "Systematic review and pooled estimates for the diagnostic accuracy of serological markers for intestinal ischemia". World J Surg 33 (7): 1374–83. doi:10.1007/s00268-009-0074-7. PMID 19424744.
- Lee ES, Bass A, Arko FR et al. (2006). "Intraoperative colon mucosal oxygen saturation during aortic surgery". The Journal of surgical research 136 (1): 19–24. doi:10.1016/j.jss.2006.05.014. PMID 16978651.
- Friedland S, Benaron D, Coogan S et al. (2007). "Diagnosis of chronic mesenteric ischemia by visible light spectroscopy during endoscopy". Gastrointest Endosc 65 (2): 294–300. doi:10.1016/j.gie.2006.05.007. PMID 17137857.
- Lee ES, Pevec WC, Link DP et al. (2008). "Use of T-stat to Predict Colonic Ischemia during and after Endovascular Aneurysm Repair: A case report". J Vasc Surg 47 (3): 632–634. doi:10.1016/j.jvs.2007.09.037. PMC 2707776. PMID 18295116.
- Smerud M, Johnson C, Stephens D (1990). "Diagnosis of bowel infarction: a comparison of plain films and CT scans in 23 cases". AJR Am J Roentgenol 154 (1): 99–103. doi:10.2214/ajr.154.1.2104734. PMID 2104734.
- Alpern M, Glazer G, Francis I (1988). "Ischemic or infarcted bowel: CT findings". Radiology 166 (1 Pt 1): 149–52. doi:10.1148/radiology.166.1.3336673. PMID 3336673.
- Taourel P, Deneuville M, Pradel J, Régent D, Bruel J (1996). "Acute mesenteric ischemia: diagnosis with contrast-enhanced CT" (PDF). Radiology 199 (3): 632–6. doi:10.1148/radiology.199.3.8637978. PMID 8637978.
- Staunton M, Malone DE (2005). "Can acute mesenteric ischemia be ruled out using computed tomography? Critically appraised topic |". Canadian Association of Radiologists Journal 56 (1): 9–12. PMID 15835585.
- Pereira JM, Sirlin CB, Pinto PS, Jeffrey RB, Stella DL, Casola G (2004). "Disproportionate fat stranding: a helpful CT sign in patients with acute abdominal pain". Radiographics : a review publication of the Radiological Society of North America, Inc 24 (3): 703–15. doi:10.1148/rg.243035084. PMID 15143223.
- Kao, Lillian S., and Tammy Lee. PreTest Surgery: PreTest Self-assessment and Review. New York: McGraw-Hill Medical, 2009.
- Sreenarasimhaiah J (2003). "Diagnosis and management of intestinal ischaemic disorders". BMJ 326 (7403): 1372–6. doi:10.1136/bmj.326.7403.1372. PMC 1126251. PMID 12816826.
- Meng, X; Liu, L; Jiang, H (August 2010). "Indications and procedures for second-look surgery in acute mesenteric ischemia.". Surgery today 40 (8): 700–5. PMID 20676851.
- Brandt, LJ; Boley, SJ (May 2000). "AGA technical review on intestinal ischemia. American Gastrointestinal Association.". Gastroenterology 118 (5): 954–68. doi:10.1016/s0016-5085(00)70183-1. PMID 10784596.
- Schoots IG, Koffeman GI, Legemate DA, Levi M, van Gulik TM (2004). "Systematic review of survival after acute mesenteric ischaemia according to disease aetiology". The British journal of surgery 91 (1): 17–27. doi:10.1002/bjs.4459. PMID 14716789.