Arterial occlusive mesenteric ischemia
Updates to Article Attributes
Body
was changed:
An acute superior mesenteric artery occlusion, which can then result in an acute mesenteric ischaemia, can be a life threatening event related with artery supplying of the majority of the small bowel and right side of the colon.
Epidemiology
An acute occlusion is an uncommon event that typically affect elderly patients, who are at increased risk of other cardiovascular events.
Clinical presentation
Clinical presentation is variable and unfortunately often non-specific such that the diagnosis is not made for some time. It may be dramatic with acute onset severe abdominal pain, or less well defined 4.
Pathology
Acute occlusion can be due to a number of causes 3,4 :
- embolic event : ~ 60%
- acute in situ thrombosis superimposed on atherosclerosis : 30%
- aortic dissection with involvement of the SMA origin
- slow flow / idiopathic
Risk factors therefore include:
- advanced age
- smoking
- prothrombotic tendency
- antiphospholipid antibodies, etc... 2
- valvular / cardiac abnormalities
- mechanical heart valve
- atrial fibrillation
- AMI / ventricular aneurysm
- right to left shunt
Radiographic features
CT
Computed tomography is widely accepted as the first line imaging technique in this evaluation7 due to its speed, widespread availability and ability to diagnose other causes of acute abdominal pain.
Technique
For a discussion on CT technique refer to intestinal ischaemia article.
Findings
Findings in acute superior mesenteric artery occlusion include :
- lack of enhancement of the lumen of the SMA and / or its branches
- embolism lodgement location varies
- 15% origin
- 50% just distal to the origin of the middle colic artery 5
- embolism lodgement location varies
- bowel wall
- thickness
- variable
- in pure arterial occlusion wall may be thinned (aka paper-thin wall) due to loss of intestinal muscular tone and absence of blood 6
- thickened wall may also be present but does not correlate with severity 6
- enhancement absent
- once necrotic mural gas may be present (pneumatosis intestinalis)
- thickness
- ileus
- free fluid
- portal venous / intrahepatic gas
- free intra abdominal gas
Ultrasound
Ultrasound is able to demonstrate normal flow in both SMA and SMV however is incapable of assessing side branches or bowel wall. It has little role in the acute management of this condition.
Angiography
Although once the gold standard for diagnosis, increasingly it is reserved for those patients deemed to perhaps benefit from endovascular intervention.
Treatment and prognosis
An acute SMA occlusion has a mortality of over 60 - 80% despite treatment 3,5. Treatment options include 4 :
- endovascular thrombectomy
- intraluminal papaverine
- surgical thrombectomy +/- resection of infarcted bowel
Differential diagnosesdiagnosis
- mesenteric arteritis
- splanchnic venous occlusion 1
- SMV or portal vein thrombosis rather than arterial occlusion
- chronic arterial occlusion with an other cause for abdominal pain
- identification of well formed collaterals may suggest that occlusion is chronic
- small bowel obstruction
-
Crohn's disease
- in most cases a significantly different patient group
-<p>An<strong> acute superior mesenteric artery occlusion</strong>, which can then result in an acute mesenteric ischaemia, can be a life threatening event related with artery supplying of the majority of the <a href="/articles/small_bowel(textbook)">small bowel</a> and right side of the <a href="/articles/colon">colon</a>. </p><h4>Epidemiology </h4><p>An acute occlusion is an uncommon event that typically affect elderly patients, who are at increased risk of other cardiovascular events. </p><h4>Clinical presentation</h4><p>Clinical presentation is variable and unfortunately often non-specific such that the diagnosis is not made for some time. It may be dramatic with acute onset severe abdominal pain, or less well defined <sup>4</sup>. </p><h4>Pathology</h4><p>Acute occlusion can be due to a number of causes <sup>3,4 </sup>:</p><ul>-<li>embolic event : ~ 60%</li>-<li>acute in situ thrombosis superimposed on atherosclerosis : 30%</li>-<li>-<a href="/articles/aortic_dissection" title="Aortic dissection">aortic dissection</a> with involvement of the SMA origin</li>-<li>slow flow / idiopathic </li>- +<p>An<strong> acute superior mesenteric artery occlusion</strong>, which can then result in an acute mesenteric ischaemia, can be a life threatening event related with artery supplying of the majority of the <a href="/articles/small-bowel">small bowel</a> and right side of the <a href="/articles/colon">colon</a>. </p><h4>Epidemiology </h4><p>An acute occlusion is an uncommon event that typically affect elderly patients, who are at increased risk of other cardiovascular events. </p><h4>Clinical presentation</h4><p>Clinical presentation is variable and unfortunately often non-specific such that the diagnosis is not made for some time. It may be dramatic with acute onset severe abdominal pain, or less well defined <sup>4</sup>.</p><h4>Pathology</h4><p>Acute occlusion can be due to a number of causes <sup>3,4 </sup>:</p><ul>
- +<li>embolic event : ~ 60%</li>
- +<li>acute in situ thrombosis superimposed on atherosclerosis : 30%</li>
- +<li>
- +<a href="/articles/aortic-dissection">aortic dissection</a> with involvement of the SMA origin</li>
- +<li>slow flow / idiopathic </li>
-<li>advanced age</li>-<li>smoking</li>-<li>prothrombotic tendency-<ul><li>antiphospholipid antibodies, etc... <sup>2</sup>- +<li>advanced age</li>
- +<li>smoking</li>
- +<li>prothrombotic tendency<ul><li>antiphospholipid antibodies, etc... <sup>2</sup>
-</li>-<li>valvular / cardiac abnormalities-<ul>-<li>mechanical heart valve </li>-<li>atrial fibrillation</li>-<li>AMI / ventricular aneurysm</li>- +</li>
- +<li>valvular / cardiac abnormalities<ul>
- +<li>mechanical heart valve</li>
- +<li>atrial fibrillation</li>
- +<li>AMI / ventricular aneurysm</li>
-</li>-<li>right to left shunt-<ul><li>-<a href="/articles/pfo" title="PFO">PFO</a> / <a href="/articles/atrial-septal-defect-2" title="ASD">ASD</a> with paradoxical embolism</li></ul>-</li>-</ul><h4>Radiographic features</h4><h5>CT</h5><p>Computed tomography is widely accepted as the first line imaging technique in this evaluation<sup>7</sup> due to its speed, widespread availability and ability to diagnose other causes of acute abdominal pain.</p><h6>Technique</h6><p>For a discussion on CT technique refer to <a href="/articles/intestinal-ischaemia" title="Intestinal ischaemia">intestinal ischaemia </a>article. </p><h6>Findings</h6><p>Findings in acute superior mesenteric artery occlusion include : </p><ul>-<li>lack of enhancement of the lumen of the SMA and / or its branches-<ul><li>embolism lodgement location varies-<ul>-<li>15% origin</li>- +</li>
- +<li>right to left shunt<ul><li>
- +<a href="/articles/pfo">PFO</a> / <a href="/articles/atrial-septal-defect-2">ASD</a> with paradoxical embolism</li></ul>
- +</li>
- +</ul><h4>Radiographic features</h4><h5>CT</h5><p>Computed tomography is widely accepted as the first line imaging technique in this evaluation<sup>7</sup> due to its speed, widespread availability and ability to diagnose other causes of acute abdominal pain.</p><h6>Technique</h6><p>For a discussion on CT technique refer to <a href="/articles/intestinal-ischaemia">intestinal ischaemia </a>article. </p><h6>Findings</h6><p>Findings in acute superior mesenteric artery occlusion include :</p><ul>
- +<li>lack of enhancement of the lumen of the SMA and / or its branches<ul><li>embolism lodgement location varies<ul>
- +<li>15% origin</li>
-</li>- +</li>
-</li>- +</li>
-<li>variable</li>-<li>in pure arterial occlusion wall may be thinned (aka paper-thin wall) due to-loss of intestinal muscular tone and absence of blood <sup>6</sup>-</li>- +<li>variable</li>
- +<li>in pure arterial occlusion wall may be thinned (aka paper-thin wall) due to loss of intestinal muscular tone and absence of blood <sup>6</sup>
- +</li>
-</li>- +</li>
-</li>-<li>enhancement absent</li>-<li>once necrotic mural gas may be present (<a href="/articles/intramural-gas" title="Pneumatosis intestinalis">pneumatosis intestinalis</a>) </li>- +</li>
- +<li>enhancement absent</li>
- +<li>once necrotic mural gas may be present (<a href="/articles/intramural-gas">pneumatosis intestinalis</a>) </li>
-</li>-<li>ileus</li>-<li>free fluid</li>-<li>portal venous / intrahepatic gas</li>-<li>free intra abdominal gas</li>-</ul><h5>Ultrasound</h5><p>Ultrasound is able to demonstrate normal flow in both <a href="/articles/superior-mesenteric-artery">SMA</a> and <a href="/articles/smv">SMV</a> however is incapable of assessing side branches or bowel wall. It has little role in the acute management of this condition. </p><h5>Angiography</h5><p>Although once the gold standard for diagnosis, increasingly it is reserved for those patients deemed to perhaps benefit from endovascular intervention. </p><h4>Treatment and prognosis</h4><p>An acute SMA occlusion has a mortality of over 60 - 80% despite treatment <sup>3,5</sup>. Treatment options include <sup>4 </sup>:</p><ul>-<li>endovascular thrombectomy </li>-<li>intraluminal papaverine </li>-<li>surgical thrombectomy +/- resection of infarcted bowel</li>-</ul><h4>Differential diagnoses</h4><ul>-<li><a href="/articles/mesenteric-arteritis-" title="mesenteric arteritis ">mesenteric arteritis </a></li>-<li>splanchnic venous occlusion <sup>1</sup><ul><li>SMV or <a href="/articles/portal-vein-thrombosis" title="Portal vein thrombosis">portal vein thrombosis </a>rather than arterial occlusion</li></ul>-</li>-<li>chronic arterial occlusion with an other cause for abdominal pain-<ul><li>identification of well formed collaterals may suggest that occlusion is chronic</li></ul>-</li>-<li><a href="/articles/small-bowel-obstruction">small bowel obstruction</a></li>-<li>- +</li>
- +<li>ileus</li>
- +<li>free fluid</li>
- +<li>portal venous / intrahepatic gas</li>
- +<li>free intra abdominal gas</li>
- +</ul><h5>Ultrasound</h5><p>Ultrasound is able to demonstrate normal flow in both <a href="/articles/superior-mesenteric-artery">SMA</a> and <a href="/articles/smv">SMV</a> however is incapable of assessing side branches or bowel wall. It has little role in the acute management of this condition.</p><h5>Angiography</h5><p>Although once the gold standard for diagnosis, increasingly it is reserved for those patients deemed to perhaps benefit from endovascular intervention.</p><h4>Treatment and prognosis</h4><p>An acute SMA occlusion has a mortality of over 60 - 80% despite treatment <sup>3,5</sup>. Treatment options include <sup>4 </sup>:</p><ul>
- +<li>endovascular thrombectomy</li>
- +<li>intraluminal papaverine</li>
- +<li>surgical thrombectomy +/- resection of infarcted bowel</li>
- +</ul><h4>Differential diagnosis</h4><ul>
- +<li><a href="/articles/mesenteric-arteritis-">mesenteric arteritis </a></li>
- +<li>splanchnic venous occlusion <sup>1</sup><ul><li>SMV or <a href="/articles/portal-vein-thrombosis">portal vein thrombosis </a>rather than arterial occlusion</li></ul>
- +</li>
- +<li>chronic arterial occlusion with an other cause for abdominal pain<ul><li>identification of well formed collaterals may suggest that occlusion is chronic</li></ul>
- +</li>
- +<li><a href="/articles/small-bowel-obstruction">small bowel obstruction</a></li>
- +<li>
-</li>- +</li>
Images Changes:
Image ( create )
Image 2 CT (C+ portal venous phase) ( update )
Caption
was changed:
Case 1: Thromboembolismthromboembolism
Unable to process the form. Check for errors and try again.