however , when it comes to patients who have unstable vital signs or for whome medical therapy is not indicated , ecmo ( extracorporeal membrane oxygenator ) application and emergent thromboembolectomy can be considered .
on the basis of the authors ' surgeries , we wanted to determine the indications and results of thromboembolectomy .
eight patients underwent surgery due to acute pulmonary embolisms from january 1999 to december 2004 . among them , we reviewed 7 patients who could be investigated by medical records .
one of these underwent reoperation due to recurrence of pulmonary embolism on the 13th postoperative day .
patients who had needed vasopressors for hypotension or had shown right heart dysfunction by echocardiography underwent surgery .
we performed median sternotomy under general anesthesia and then performed cardiopulmonary bypass without cardiac arrest . after making incisions to the pulmonary arteries longitudinally , we removed the thromboembolisms and cautiously compressed both lungs after opening both pleurae using an uncapped yankauer sucker . for artery cannulation , we used the ascending aorta in 7 cases and the femoral artery in one case . on the other hand ,
for venous cannulation , we used both the superior vena cava ( svc ) and inferior vena cava ( ivc ) in 7 cases and the femoral vein in one case .
the one case of using the femoral artery and vein was the patient who had suffered from hypotension in the operating room , so we cannulated the femoral artery and vein and ran the cpb first and then continued the surgery .
the mean duration from admission to operation was 3 days , which included the cases referred from other departments .
the total patients were 7 cases ( 4 males , 3 females ) . because one female had a reoperation on the 13 postoperative day , there were a total of 8 operations .
the main symptoms were dyspnea in 4 cases , chest pain and discomfort in 2 cases , palpitation in one case , and syncope in one case .
however , a vasopressor was infused into the two patients who had suffered from hypotension .
the mean respiratory rate was 27 breaths per minute ( 22 to 36 ) and the mean pulse rate was 113 beats per minute ( 98 to 120 ) .
we diagnosed the disease using chest computed tomography and lung perfusion scan , echocardiography and pulmonary angiography . in the chest computed tomography scans ,
echocardiography showed right heart dilatation in 6 cases , and moderate tricuspid regurgitation was noted in 3 of them . a preoperative check of d - dimer was performed in 4 cases , which were found to be elevated to > 1.0 , 3.28 , 1.84 , and 16.8 mcg / ml .
troponin i was elevated to 2 , 2 , and 3.43 ng / ml in 3 cases .
we calculated the difference in oxygen pressure ( aado2 ) and the values were elevated in 6 cases ( table 1 ) .
the causes of pulmonary artery thromboembolism were deep vein thrombosis in 4 cases , previous knee transplantation in 2 , cases and schizophrenia in 2 cases .
of the remaining cases , one each was caused by right atrial thrombosis , patent foramen ovale ( pfo ) with cerebral stroke ( for which we performed thromboembolectomy with pfo primary closure ) and steroid taking due to renal failure .
there were two patients who had used vasopressors before surgery and one of them underwent cardiopulmonary resuscitation .
we infused heparin to 4 patients before surgery , and we inserted an ivc filter below the renal vein in 4 cases .
one patient suffered from pleural and pericardial effusion , but went home without any special treatment .
the patients who had a long hospital stay needed treatment for psychotic problems , and reoperation made for a long hospitalization .
two patients died , one on the operative day and the other on the first postoperative day .
one was in brain death after cpr , and the other died of right heart failure with myocardial infarction .
the patient in brain death underwent the operation due to the family 's insistence ( table 2 ) .
four patients who came back for follow - up among the five surviving cases lived at least 5 years after their operations .
the main clinical symptoms were acute dyspnea and chest comfort , and other symptoms are hypoxemia and hypotension without specific previous disease .
twenty percent of patients show the normal range of arterial oxygen pressure and the normal difference between alveolar and arterial oxygen pressure ( aado2 ) .
hemodynamic changes can be shown in the time when 30~50% of pulmonary arteries are plugged with thrombi .
acute pulmonary thromboembolism can be categorized into massive and sub - massive groups . in massive acute pulmonary thromboembolism
, there can be cases of systolic blood pressure below 90 mmhg , systolic blood pressure decreases of more than 40 mmhg over the course of 15 minutes or more , and cardiogenic shock .
on the other hand , sub - massive acute pulmonary thromboembolism evidences right heart dysfunction even when it shows a hemodynamically stable state .
the risk factors of acute pulmonary thromboembolism include old age , history of deep vein thrombosis , four - limb limitation due to neurogenic problems , long bedridden periods due to cardiac or acute pulmonary injury , neoplasm , hormonal therapy , congenital or acquired thrombophilia , oral contraception , pericarditis , and history of pulmonary thromboembolism . in patients with deep vein thrombosis in the proximal lower extremity without chest symptoms ,
seventy percent of the detected pulmonary thromboembolisms are combined with deep vein thrombosis in the lower extremities . among these combined cases ,
limitation of movement due to neurogenic disease , being over 75 years old , and cardiopulmonary disease or neoplasm are risk factors for death by acute pulmonary thromboembolism .
danilo et al . reported that moderately depressive patients with movement limitations were in danger of pulmonary thromboembolism .
the score takes into account age over 65 years , history of arrhythmia , thrombus and pulmonary embolism , history of operation within the most recent one month , history of fracture , progressive cancer , pain of a unilateral lower extremity , hemoptysis , heart rate over 75 beats per minute , pain on palpation of the lower extremity vein , and unilateral edema in the lower extremity .
clinical possibilities can be classified into three grades ( low , intermediate , high ) according to the grade of individual risk factors .
other diagnostic tools are chemical tests such as pro - bnp , bnp , troponin , echocardiography , chest computed tomography , and lung perfusion scan .
echocardiography can reveal the level of pressure overload to the right ventricle , through the signs of a diameter ratio between the right and left ventricle of more than 1 , right ventricular dilatation , right ventricular hypokinesis , and the degree of ventricular septal bowing .
in particular , it is said that the degree of ventricular septal bowing is useful in predicting death . among the patients diagnosed with pulmonary thromboembolism , hemodynamically
if there is an abnormal finding of the right heart , the patient can be treated with thrombolytics under close observation .
initial therapies include anticoagulation ( unfractionated heparin , low molecular weight heparin , fondaparinux , warfarin ) , thrombolytics , percutaneous thromboembolectomy , and operative treatment .
warfarin therapy must be continued for three months ( target inr : 2.0~3.0 ) . in the cases with risk factors such as male gender , old age , malignancy , and pulmonary embolism without special preceding causes ,
however , warfarin therapy must be continued at least three months due to the increased possibility of recurrence .
thrombolytics can not be used in cases of cerebral diseases , intractable hypertension , or within three weeks post - operatively .
an ivc filter is indicated for cases of contraindication of anticoagulation therapy , the failure of anticoagulation therapy , cardiopulmonary dysfunction with arrhythmogenic thrombosis , high risk patients for operation and the patient taking thrombolytics due to proximal arrhythmogenic thrombosis .
pulmonary thromboembolectomy has to be performed 
 whenever several medical treatments do not show the effect in the cases of unstable blood pressure , hypoxemia , imbalance of electrolytes , or acidosis .
if an emergency operation is difficult to perform , the application of ecmo can be helpful to maintain survival .
the first indication is the case of confirmed massive pulmonary thromboembolism with hemodynamic changes . in this case , right heart dysfunction or the need for vasopressors becomes evident .
the second one is hemodynamic instability such as shock , in spite of heparin infusion or supportive care for stable vital signs .
if there is a massive thrombus in the proximal lower limb and a percutaneous thromboembolectomy using a catheter can not be performed , an operation has to be considered even though the vital signs are stable .
although noninvasive therapies such as anticoagulation and thrombolytics tend to gradually replace surgical interventions , in light of this study , we suggest that emergency pulmonary thromboembolectomies are needed for patients who are in a hemodynamically unstable state or have a right heart dysfunction .
furthermore , patients whose movements are limited due to psychotic problems are in danger of pulmonary thromboembolism . therefore
 backgroundacute pulmonary thromboembolism is fatal because of abruptly occurring hypoxemia and right ventricular failure . 
 there are several treatment modalities , including anticoagulation , thrombolytics , ecmo ( extracorporeal membrane oxygenator ) , and thromboembolectomy , for managing acute pulmonary thromboembolism.materials and methodsmedical records from january 1999 to december 2004 at our institution were retrospectively reviewed for pulmonary thromboembolectomy . 
 there were 7 patients ( 4 men and 3 women ) , who underwent a total of 8 operations because one patient had post - operative recurrent emboli and underwent reoperation . 
 surgery was indicatedfor mild hypoxemia and performed with cpb ( cardiopulmonary bypass ) in a beating heart state.resultsthe patients had several symptoms , such as dyspnea , chest discomfort , and palpitation . 
 four patients had deep vein thromboembolisms and 3 had psychotic problems , specifically schizophrenia . 
 post - operative complications included hemothorax , pleural effusion , and pericardial effusion . 
 there were two hospital deaths , one each by brain death and right heart failure.conclusionemergency operation should be performed when medical treatments are no longer effective . 
INTRODUCTION
MATERIAL AND METHODS
RESULTS
DISCUSSION
CONCLUSION