Pulmonary Embolism
Pulmonary embolism (PE) involves occlusion of a pulmonary artery by an embolus, most often a thrombus, obstructing blood flow to the lungs. Impairment of pulmonary circulation leads to severe ventilation-perfusion mismatching of the lungs, terminating in hypoxemia and respiratory failure. Most PEs are sequelae of Deep Vein Thrombosis (DVT), resulting from the breakage and propagation of a venous thrombus formed within the extremities to a pulmonary artery.As DVT commonly precedes PE, risk factors for PE overlap with risk factors for DVT. These include a sedentary lifestyle, prior surgery, trauma, history of DVT, and hypertension. A sedentary lifestyle and lack of movement are critical modifiable risk factors for PE. Immobility reduces the rate of leg muscle contraction, enhancing thrombus formation in vessels of the calves that may propagate to the lungs. Thus, physical activity is essential in preventing PE. Complications
Diseases of arterial occlusion may progress into life-threatening conditions with improper prevention or management. Myocardial infarction, gangrene, and ischemic stroke are among the complications of severe arterial occlusion. Myocardial Infarction
A myocardial infarction (MI), or heart attack, arises from complete occlusion of a coronary artery. The most frequent cause of MI is the rupturing of an atherosclerotic plaque formed in CAD. Plaque rupture exposes the subendothelial matrix beneath the plaque, initiating thrombus formation within the vasculature. The thrombus deposits on the ruptured plaque to completely block the coronary artery, halting oxygen supply to cardiomyocytes. Under hypoxia, cardiomyocytes perform anaerobic respiration, producing more lactate. With blocked coronary circulation, lactate clearance from cardiomyocytes is also hindered.
This procedure involves bypassing the blocked portion of the artery by replacing it with a healthy vessel from elsewhere in the body. The surgeon attaches one end of the new vessel right before the blockage, and the other end in the area after the affected portion. This reestablishes proper blood flow toward the desired area. Endarterectomy
An endarterectomy is an intervention aiming to remove accumulated plaques directly from the affected artery. This involves an incision on the side of the neck of the affected artery. The plaque is then exposed and removed accordingly, with the artery then stitched back together. With the plaque removed, blood can travel through the artery unimpeded. Embolectomy
An embolectomy is a procedure conducted when a blockage moves from its original site to another place in the body, thus forming an embolus. There are two methods of performing embolectomy. The first method is catheter embolectomy, which involves the insertion of a catheter into the affected artery and the subsequent removal of the embolus. This option is minimally invasive, and thus lowers risk and recovery time. The other option is a traditional surgical option, where the surgeon will expose the affected region, open the blood vessel and remove the embolus. Blood-thinning Medication
Blood-thinning medications are beneficial short-term options in managing arterial occlusion. Anticoagulants such as warfarin and antiplatelets such as aspirin and clopidogrel reduce the risk of thrombosis by making blood flow easily through arteries. Side effects include increased bleeding and heavier bruising. == References ==