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a 70-year - old woman ( height : 156 cm , body weight : 48 kg ) with lower abdominal pain was admitted and associated symptoms were fever , nausea , vomiting and diaphoresis which started from the day previous to her admission . on abdominal computed tomography ( ct ) , right ovarian cyst in size of 2.5 cm was found , and an acute appendicitis was diagnosed by an abdominal ultrasonography .
an elective operation was scheduled under the collaboration of gynecology and general surgery . in the patient 's past medical history , she had taken digoxin , dilatrend , nitrate , telmisartan , and thiazide for 5 years because of hypertension , congestive heart failure , af , and right coronary artery 90% stenosis on coronary angiography . an electrocardiogram before operation showed af with ventricular response 90 - 100 times / min , left ventricular hypertrophy .
cardiomegaly and pleural effusion were found on chest x - ray . on transthoracic echocardiography ( tte ) ,
ejection fraction was 55% and left atrial enlargement , right atrial enlargement and eccentric hypertrophy with decreased mobility of the inferior wall of the left ventricle were shown . a moderate aortic valve insufficiency , aortic valve sclerosis , mild aortic stenosis , and severe posterior mitral valve leaflet calcification were also found and the width of mitral valve measured by pressure half - time was 1.92 cm .
a chronic cerebral infarction in the right posterior cerebral artery was found on brain ct with symptoms of dysarthria .
signs of dehydration on physical examinations with prerenal azotemia of fena 0.1% and serum creatinine of 1.7 mg / dl on blood test led us to start an fluid therapy .
glycopyrrolate 0.2 mg i m was premedicated at 30 minutes pre - operation . the patient 's blood pressure ( bp ) was 130/50 mmhg , ventricular response 90 - 100 times / min , and arterial oxygen saturation 97% when she arrived at the operation room .
the induction of anesthesia was initiated with injecting 2 ml of 2% lidocaine to reduce injection pain and propofol ( diprivan astrazeneca , uk ) and remifentanil ( ultiva glaxosmithkline , uk ) were injected using a target - controlled infuser ( orchestra fresenius vial , france ) . after confirming the patient 's being unconscious , rocuronium 40 mg was injected and then endotracheal intubation was performed with close monitoring of arterial blood pressure .
ventilation with 100% o2 was given while central venous catheterization was placed in right jugular vein .
after the induction of anesthesia , the patient 's vital sign showed no hemodynamic disorder with systolic bp 130 - 150 mmhg , diastolic bp 40 - 60 mmhg , ventricular response approximately 100 - 110 times / min , and central venous pressure ( cvp ) 8 - 9 mmhg .
the effect site concentration was injected as 2.5 - 3.0 g / ml of propofol and and 2.0 ng / ml of remifentanil .
after the lower abdomen laparotomy at obstetrics and gynecology for the right ovary cystectomy , a small bowel infarction from jejunum to ileum was detected .
the authors suspected a mesenteric arterial embolism based on the patient 's previous medical history .
a transesophageal echocardiology ( sonosite micromaxx , bothell , usa ) probe was immediately inserted and a spontaneous echo contrast ( sec or " smoke " ) in the left atrium ( la ) and a 13  18 mm size thrombus in the laa was detected ( fig .
the findings in tee made a mesenteric arterial embolism highly suspicious for the cause of the small bowel infarction .
no hemodynamic instability was observed through whole procedure of operation and the patient was transferred to the intensive care unit with endotracheal tube inserted . after confirming her awareness and the absence of any neurologic disorder , extubation was performed in intensive care unit . to minimize the risk of hemorrhage of the anastomosis site
it was started with low molecular weight heparin 3 days after the operation and oral warfarin was added 5 days after the operation .
mesenteric infarction is induced by the embolism in the left atrium , left ventricle , and heart valves ; the superior mesenteric artery is anatomically the most vulnerable to infarction due to its large diameter and the acute angle takeoff from the aorta , but the inferior mesenteric artery is rarely vulnerable due to its small diameter . for preventing injury from ischemia ,
the main mesenteric blood vessels have extensive collateral circulation ; however , when the mesenteric arterial embolism occurs , the mid - segment of the jejunum , which is the farthest from the collateral circulation of the celiac artery and inferior mesenteric artery , becomes most vulnerable to ischemia .
an acute hypoperfusion state induced by mesenteric arterial vascular disorder forms 60 - 70% of the total mesenteric ischemia with mortality rate exceeding 60% .
symptoms can vary from acute severe , nonremitting abdominal pain to vague abdominal pain . and associated symptoms may include nausea and vomiting , transient diarrhea , and bloody stools .
however the absence of any specific clinical symptom and no indicator shown in blood test or plain x - ray make early diagnosis challenging which may end up in delayed treatment .
it is highly suspicious in aged patients with af and a previous history of cardiac and vascular disease like recent myocardial infarction , rheumatic heart disease , and recent cardiac catheterization .
mesenteric angiography is the most reliable diagnostic tool and also helps locating exact site of blockage .
an early angiography on a patient suspected of arterial ischemia is widely accepted to decrease the mortality rate of mesenteric ischemia patients .
there was no comment about the thrombus in the la and the laa on the pre - operative tte examination ; it is difficult to observe a laa by tte , so the sensitivity of the tte of the la or laa is known as 39 - 63% .
in contrast , by tee , observing the posterior structures of the heart , such as the la and laa is much easier , the sensitivity and the specificity of thrombus in the la was reported as 93 - 100% and 99 - 100% , respectively .
tee of patients with af shows a sec in the la or laa , which is known to increase the risk of thromboembolism .
estimation of blood flow velocity in the left or right atrium and left and right atrial appendage permits a more quantifiable measure of stasis .
the risk of stroke increases sharply with marked reductions in blood flow velocity ( < 15 cm / sec ) , particularly in the laa or posterior left atrium .
sec refers to the presence of dynamic , smoke - like echoes seen during echocardiogram in the la or laa ; it is known that sec is formed by a red blood cell rouleaux formation on stagnant flow condition .
difficulty to quantificate sec by identifyimg as a fluid whirlwind of smoke is due to differences between the frequency and the gain of an echocardiogram probe .
sec may be missed in the case where the gain is too low or the test room is too bright .
sec should be observed under high gain with a high - frequency probe over 5 mhz which a uniform noise is seen in the la .
the laa peak outflow velocity can be estimated by tee and sec semiquantitatively graded as marked or dense if present throughout the entire cardiac cycle , or faint when intermittent .
the goal of treating af include maintaining sinus rhythm , controlling heart rate , and preventing thromboembolism by using anticoagulant therapy ; the risk stratification of thromboembolism is most important for anticoagulant therapy .
the high risk factors of thromboembolism include a previous history of thromboembolism , mitral valve stenosis , and a mechanical valve ; moderate risk factors are ages over 75 , hypertension , heart failure , left ventricular ejection fraction less than 35% , and diabetes .
females , ages from 65 to 74 , coronary arterial diseases , and thyrotoxicosis correspond to low risk factors . during anticoagulation therapy , aspirin 81 - 325 mg / day should be taken in the case where there are no risk factors or only low risk factors ; aspirin or warfarin ( inr 2 - 3 ) should be taken in case of 1 moderate risk factor .
warfarin should be taken in case of 2 or more moderate risk factors or the existence of a high risk factor in case of a mechanical valve , inr should be maintained more than 2.5 at minimum .
chads2 ( cardiac failure , hypertension , age , diabetes , stroke [ doubled ] ) , another stroke risk stratification , scores 1 for heart failure , hypertension , ages over 75 , and diabetes and scores 2 for a previous history of a stroke or transient ischemic attack and adds the scores , and then classifies score 0 as a low risk group , scores 1 as a moderate risk group and scores over 2 as a high risk group .
aspirin is used for the low risk group , aspirin or warfarin is selectively used for the moderate risk group , and the high risk group with scores over 2 should be performed with anticoagulant therapy . in this case , the patient should have been initiated an anticoagulant therapy considering her high blood pressure , congestive heart failure , and chronic cerebral infarction detected by the brain ct .
in addition , aged patients with af showing mitral annular calcification on echocardiography , there is a high potency of thromboembolism , even without mitral stenosis , mitral regurgitation , or prolapsed leaflet .
the authors suggest that risk stratification before operation should be performed on af patients with thromboebolism risk factors ; hemodynamic and neurologic observation are needed on the induction , maintenance , and emergence period of anesthesia ; tee during operation can be helpful for these patients .
acute mesenteric ischemia and infarction is an emergent situation associated with high mortality , commonly due to emboli or thrombosis of the mesenteric arteries . 
 embolism to the mesenteric arteries is most frequently due to a dislodged thrombus from the left atrium , left ventricle , or cardiac valves . 
 we report a case of 70-year - old female patient with an acute small bowel infarction due to a mesenteric artery embolism dislodged from a left atrial appendage detected by intraoperative transesophageal echocardiography and followed by anticoagulation therapy .