a) Acute Massive Pulmonary Entbolism
Before the era of open-heart surgery, Trendelenburg (1908) described technique of open pulmonary embolectomy. The technique was abandoned because of unacceptable mortality. Cooley (1 96 1) published pulmonary embolectomy under cardio pulmonary bypass.
Indications for Surgery
Acute pulmonary embolism with haemodynamic instability and hypoxaemia is
nearly always fatal. Mortality is reported to be 50 per cent, if 50 per cent of
pulmonay vasculature is obstructed. In pulmonary bifurcation block this approaches 100 per cent. In patients who cannot have thrombolytic treatment,surgical embolectomy is indicated. Diagnosis is made by ECG, echocardiography(trans thoracic or trans oesophageal), CT scan with contrast medium and MRI.Even though pulmonary angiography is the best diagnostic tool, it can seldom be performed in a haemodynamically unstable patient.
Technique of Operation
Patients who are very unstable will have to be put on bypass by cannulation of femoral artery and vein before anaesthesia and median sternotomy are done.Ascending aortic cannulation and separate cannulation of SVC and IVC are done and snares passed around these for total cardiopulmonary bypass. A left atrial vent catheter is passed through right supeiior pulmonary vein to decoinpress the heart.
nearly always fatal. Mortality is reported to be 50 per cent, if 50 per cent of
pulmonay vasculature is obstructed. In pulmonary bifurcation block this approaches 100 per cent. In patients who cannot have thrombolytic treatment,surgical embolectomy is indicated. Diagnosis is made by ECG, echocardiography(trans thoracic or trans oesophageal), CT scan with contrast medium and MRI.Even though pulmonary angiography is the best diagnostic tool, it can seldom be performed in a haemodynamically unstable patient.
Technique of Operation
Patients who are very unstable will have to be put on bypass by cannulation of femoral artery and vein before anaesthesia and median sternotomy are done.Ascending aortic cannulation and separate cannulation of SVC and IVC are done and snares passed around these for total cardiopulmonary bypass. A left atrial vent catheter is passed through right supeiior pulmonary vein to decoinpress the heart.
Aorta is clamped and cold blood cardioplegia given to the aortic root. The pulmonary trunk is incised vertically upto the bifurcation or if necessary into the left pulmonary artery. The emboli are removed and iT necessary the right pulmonary artery is separately opened between retracted ascending aorta and superior vena cava. A sterile fibre optic bronchoscope can be used to enter secondary and tertiary branches to remove clots. Pleurae are widely opened and lungs squeezed to remove the remaining clots. Right atrium is opened and clots from atrium and ventricle removed. After closirig right atrium and pulmonary artery, de-airing is done and aortic clamp is removed. Patient is weaned off by-pass and chest closed.Prophylactically, inferior vena caval filter is applied.
Results
The mortality in different series is reported between 3 and 36 per cent. In haemodynamically uilstable patients this could be as high as 75 per cent.
b) Chronic pulmonary Thromboembolism
The operation recommended is pulinonxy thrombo enduterectomy.
Indication
The main indication for surgery is when patients with cl~ronic thromboembolism have ventilatory or haemodynamic impairment at rest or exercise. Patients with obstruction of only one pulmonary artery should also be considered for operation if they are physically very active and they reside at high altitudes. Patients, who are symptomatic but have near normal haemodynarnics at rest but develop severe pulmonary hypertension on exercise, should also have surgery. For successful surgery the clots should be in branch, lobar or proximal segmental arteries. If the blocks are beyond that, it should be considered inoperable.Severe underlying obstructive or restrictive pullnonary disease, advanced age,severe light ventricular failure and co morbid conditions should be considered as contra indications.
Results
The mortality in different series is reported between 3 and 36 per cent. In haemodynamically uilstable patients this could be as high as 75 per cent.
b) Chronic pulmonary Thromboembolism
The operation recommended is pulinonxy thrombo enduterectomy.
Indication
The main indication for surgery is when patients with cl~ronic thromboembolism have ventilatory or haemodynamic impairment at rest or exercise. Patients with obstruction of only one pulmonary artery should also be considered for operation if they are physically very active and they reside at high altitudes. Patients, who are symptomatic but have near normal haemodynarnics at rest but develop severe pulmonary hypertension on exercise, should also have surgery. For successful surgery the clots should be in branch, lobar or proximal segmental arteries. If the blocks are beyond that, it should be considered inoperable.Severe underlying obstructive or restrictive pullnonary disease, advanced age,severe light ventricular failure and co morbid conditions should be considered as contra indications.
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