Bonveda's Blog

The classic signs and symptoms of acute arterial occlusion are described by the “six Ps” :
pain, pulselessness, paresthesias , pallor, paralysis, and poikilothermy ( cold temperature).
In reality, however, symptoms may very greatly from patient to patient depending on the arterial anatomy and collateral blood supply to the extremity. The patient with acute thrombosis of a previously stenotic artery often has extensive collateral circulation to the extremity and may experience minimal or no symptoms. By contrast, the patient with sudden occlusion of a previously normal artery is unlikely to have developed significant collaterals and will probably experience severe limb-threatening ischemia as described by the six Ps. As noted, acute arterial occlusion is either thrombotic or embolic in nature, with 90% of emboli to he lower extremity and virtually all emboli to the arm originating from a cardiac source. Thrombotic occlusion usually occurs in the setting of preexisting atherosclerosis but many also be a result of traumatic or iatrogenic injury. The diagnosis is made initially based on the history and physical examination, and an attempt is made to assess the etiology. Normal pulses in the contralateral extremity, absence of a history of claudication, and the presence of atrial fibrillation or valvular heart disease suggest an embolic etiology, whereas abnormal contralateral pulse examination, a history of preexisting vascular disease, and the absence of cardiac pathology suggest a thrombotic cause. Regardless of the etiology, the patient is immediately heparinized to prevent antegrade and retrograde propagation of the thromboembolic process. Embolic occlusions are treated with simple embolectomy, whereas thrombotic occlusions require bypass grafting, as thrombectomy alone is doomed to reocclusion. If the degree of ischemia is severe or if the etiology is clearly embolic, the patient is taken directly to the operating room. If doubt exists as to the nature and location of the occlusion, however, and the patient’s condition permits, arteriography is performed to aid in planning the operation.
In patients with embolic occlusions, heparin should be continued postoperatively and a thorough search made for the source of the embolus.
An alternative treatment option in patients without severe ischemia is the use of intra-arterial thrombolytic agents, often in conjunction with mechanical thrombectomy devices, to dissolve the offending thrombus. Proponents argue that reduction in the clot volume may reduce the frequency and magnitude of operative interventions required in these patients, but this has yet to be proved.