Acute arterial occlusions
Definition[edit | edit source]
- Sudden limb perfusion disorder leading (unless quickly removed) to irreversible changes distal to the arterial occlusion,
- can lead to limb loss, a life threatening condition.
Causes[edit | edit source]
The most common causes of acute arterial occlusions are:
- embolism in 70% (atrial fibrillation, myocardial infarction, cardiomyopathy, endocarditis, valve defects, artificial valve failure, myxoma, left ventricular aneurysm, paradoxical embolization),
- thrombosis in 20% (prosthesis failure, atherosclerosis, aneurysm thrombosis, entrapment syndrome, prothrombotic state, dehydration, hypotension, atherosclerotic ulcer),
- trauma (iatrogenic injury, exogenous trauma, bleeding).
Other less common causes may be:
- artery wall dissection,
- external wall compression,
- hemodynamic changes (phlegmasia coerulea dolens, shock),
- compartment syndrome.
Pathogenesis[edit | edit source]
- Sudden closure leads to the formation of an attached thrombus , which propagates proximally and distally.
- The degree of ischemia depends on collateral circulation, which is formed especially in chronic ischemia due to the growing demand of tissues for oxygen.
- Ischemia is best tolerated by the skin and subcutaneous tissue (up to 12 hours), muscles and bone are necrotic after 6-8 hours, nerves after 2-4 hours.
- Effects of ischemia on cells: lactate production , xanthine oxidase expression , reperfusion injury, cell edema (may be caused by compartment syndrome after circulatory restoration).
- Myonephropathic metabolic syndrome is a systemic consequence of reperfusion. Flooding the body with acidic products and potassium or myoglobin leads to renal and respiratory insufficiency with high mortality.
- Sources of embolization: most often heart (after transmural MI ), atrial fibrillation , aneurysm , valve defects , rarely myxoma , iatrogenic, paradoxical embolization .
Clinical picture[edit | edit source]
- Sudden pain, lack of peripheral pulsations, paleness and coldness of the skin, impaired sensitivity and mobility.
- The symptoms have a hosiery or glove character.
Differential diagnosis[edit | edit source]
- Differential diagnosis between embolism and thrombosis can be difficult.
- We suggest embolic closure when patient has a negative history of claudication, normal pulsation on the other limb, arrhythmia .
- Thrombosis is manifested by claudications, pulse deficit and the other limb.
- This is not absolutely true (even the sclerotic artery can be embulated,…).
- In case of clinically clear embolism, no further examination is usually necessary, in case of thrombosis arteriography is performed
Therapy[edit | edit source]
We distinguish between general and local therapy.
General therapy[edit | edit source]
- Always immediate administration of heparin - bolus 10,000 j iv (prevents the progression of the attached thrombus, which could close the collateral bloodstream).
- We pay maximum attention to the overall condition of the patient (especially cardiac).
- Prevention of myonephropathic syndrome - glucose infusion with insulin (support of potassium deposition in cells), improvement of diuresis by hydration and administration of mannitol , PGE 1 .
Local therapy[edit | edit source]
- The most effective surgery is embolectomy with Fogarty catheter ;
- it can be performed under local anesthesia , from the incision we insert a catheter into the artery distal to the occlusion with an inflatable balloon at the end and release the embolus;
- exceptionally, direct embolectomy is required (eg in bifurcation of the popliteal artery );
- after a perfect embolectomy, we can interrupt heparinization (unless required by the underlying disease).
- In thrombosis, the removal of the thrombus is usually not enough for a long time, it is possible to use other methods - thrombectomy supplemented by revascularization, TEA or bypass , possibly. PTA .
Pharmacologic thrombolysis ( fibrinolysis )[edit | edit source]
- Targeted application
- either orthogradely in peripheral thrombosis or, on the other hand, in femoral or pelvic artery thrombosis;
- we start with the instillation of a high dose, which we reduce after the initial recanalization;
- the procedure is monitored by repeated angiographies every 6–12 hours;
- duration of infusion according to the effect (not more than 72 h);
- we monitor coagulation values.
- streptokinase ;
- urokinase ;
- tPA (tissue plasminogen activator).
- critical ischemia (it is not possible to wait hours for the effect);
- Florida ulcer disease;
- CMP less than 3 months ago;
- intracranial tumor ;
- vascular malformations;
- bacterial endocarditis .
- recent operations;
- trauma ;
- hypertension ;
- heart defects ;
- coagulopathy ;
- liver disease;
- streptokinase allergy
- bleeding at the injection site and elsewhere (GIT, intracranially).
Sources[edit | edit source]
Related articles[edit | edit source]
References[edit | edit source]
- ZEMAN, Miroslav, et al. Speciální chirurgie. 2. vydání. Praha : Galén, 2006. 575 s. ISBN 80-7262-260-9.
Source[edit | edit source]
- BENEŠ, Jiří. Studijní materiály [online]. [cit. 14.5.2010]. <http://jirben.wz.cz>.