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Pulmonary embolism may be preventable in those with risk factors. People admitted to hospital may receive preventative medication, including unfractionated heparin, low molecular weight heparin (LMWH), or fondaparinux, and anti-thrombosis stockings to reduce the risk of a DVT in the leg that could dislodge and migrate to the lungs.
Following the completion of warfarin in those with prior PE, long-term aspirin is useful to prevent recurrence.
Standard medical treatment consists of anticoagulants (blood thinners), diuretics, and oxygen. Lifelong anticoagulation is recommended, even after PEA. Routine inferior vena cava filter placement is not recommended.
In patients with non-operable CTEPH or persistent/recurrent PH after PEA, there is evidence for benefit from pulmonary vasodilator drug treatment. The microvascular disease component in CTEPH has provided the rationale for off-label use of drugs approved for PAH. Currently, only riociguat (a stimulator of soluble guanylate cyclase) is approved for treatment of adults with inoperable CTEPH or persistent or recurrent CTEPH after surgical treatment. Other drug trials are ongoing in patients with inoperable CTEPH, with macitentan recently proving efficacy and safety in MERIT
Decision making for patients with CTEPH can be complex and needs to be managed by CTEPH teams in expert centres. CTEPH teams comprise cardiologists and pulmonologists with specialist PH training, radiologists, experienced PEA surgeons with a significant caseload of CTEPH patients per year and physicians with percutaneous interventional expertise. Currently, there are three recognised targeted treatment options available: pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and pulmonary vasodilator drug treatment for inoperable patients.
Specialist imaging using either magnetic resonance or invasive PA is necessary to determine risks and benefits of interventional treatment with PEA or BPA.
Anticoagulant therapy is the mainstay of treatment. Acutely, supportive treatments, such as oxygen or analgesia, may be required. People are often admitted to hospital in the early stages of treatment, and tend to remain under inpatient care until the INR has reached therapeutic levels. Increasingly, however, low-risk cases are managed at home in a fashion already common in the treatment of DVT. Evidence to support one approach versus the other is weak.
Prevention of atherosclerosis, which is a major risk factor of arterial embolism, can be performed e.g. by dieting, physical exercise and smoking cessation.
In case of high risk for developing thromboembolism, antithrombotic medication such as warfarin or coumadin may be taken prophylactically. Antiplatelet drugs may also be needed.
Treatment is aimed at controlling symptoms and improving the interrupted blood flow to the affected area of the body.
Medications include:
- Antithrombotic medication. These are commonly given because thromboembolism is the major cause of arterial embolism. Examples are:
- Anticoagulants (such as warfarin or heparin) and antiplatelet medication (such as aspirin, ticlopidine, and clopidogrel) can prevent new clots from forming
- Thrombolytics (such as streptokinase) can dissolve clots
- Painkillers given intravenously
- Vasodilators to relax and dilate blood vessels.
Appropriate drug treatments successfully produces thrombolysis and removal of the clot in 50% to 80% of all cases.
Antithrombotic agents may be administered directly onto the clot in the vessel using a flexible catheter ("intra-arterial thrombolysis"). Intra-arterial thrombolysis reduces thromboembolic occlusion by 95% in 50% of cases, and restores adequate blood flow in 50% to 80% of cases.
Surgical procedures include:
- Arterial bypass surgery to create another source of blood supply
- Embolectomy, to remove the embolus, with various techniques available:
- Thromboaspiration
- Angioplasty with balloon catheterization with or without implanting a stent Balloon catheterization or open embolectomy surgery reduces mortality by nearly 50% and the need for limb amputation by approximately 35%.
- Embolectomy by open surgery on the artery
If extensive necrosis and gangrene has set in an arm or leg, the limb may have to be amputated. Limb amputation is in itself usually remarkably well tolerated, but is associated with a substantial mortality (~50%), primarily because of the severity of the diseases in patients where it is indicated.
Many pathways are involved in the abnormal proliferation and contraction of the smooth muscle cells of the pulmonary arteries in patients with pulmonary arterial hypertension. Three of these pathways are important since they have been targeted with drugs — endothelin receptor antagonists, phosphodiesterase type 5 (PDE-5) inhibitors, and prostacyclin derivatives.
The dual (ET and ET) endothelin receptor antagonist bosentan was approved in 2001. Sitaxentan (Thelin) was approved for use in Canada, Australia, and the European Union, but not in the United States. In 2010, Pfizer withdrew Thelin worldwide because of fatal liver complications. A similar drug, ambrisentan is marketed as Letairis in the U.S. by Gilead Sciences.
The epidemiology of pulmonary heart disease (cor pulmonale) accounts for 7% of all heart disease in the U.S. According to Weitzenblum, et al., the mortality that is related to cor pulmonale is not easy to ascertain, as it is a complication of COPD.
The treatment for cor pulmonale can include the following: antibiotics, expectorants, oxygen therapy, diuretics, digitalis, vasodilators, and anticoagulants. Some studies have indicated that Shenmai injection with conventional treatment is safe and effective for cor pulmonale (chronic).
Treatment requires diuretics (to decrease strain on the heart). Oxygen is often required to resolve the shortness of breath. Additionally, oxygen to the lungs also helps relax the blood vessels and eases right heart failure. When wheezing is present, the majority of individuals require a bronchodilator. A variety of drugs have been developed to relax the blood vessels in the lung, calcium channel blockers are used but only work in few cases and according to NICE are not recommended for use at all.
Anticoagulants are used when venous thromboembolism is present. Venesection is used in severe secondary polycythaemia (because of hypoxia), which improves symptoms though survival rate has not been proven to increase.Finally, transplantation of single/double lung in extreme cases of cor pulmonale is also an option.
In treating pulmonary insufficiency, it should be determined if pulmonary hypertension is causing the problem to therefore begin the most appropriate therapy as soon as possible (primary pulmonary hypertension or secondary pulmonary hypertension due to thromboembolism). Furthermore, pulmonary insufficiency is generally treated by addressing the underlying condition, in certain cases, the pulmonary valve may be surgically replaced.
For newborns with transposition, prostaglandins can be given to keep the ductus arteriosus open which allows mixing of the otherwise isolated pulmonary and systemic circuits. Thus oxygenated blood that recirculates back to the lungs can mix with blood that circulates throughout the body. The arterial switch operation is the definitive treatment for dextro- transposition. Rarely the arterial switch is not feasible due to particular coronary artery anatomy and an atrial switch operation is preferred.
The treatment for thrombosis depends on whether it is in a vein or an artery, the impact on the person, and the risk of complications from treatment.
Arterial thrombosis is platelet-rich, and inhibition of platelet aggregation with antiplatelet drugs such as aspirin may reduce the risk of recurrence or progression.
An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule (fat embolism), a bubble of air or other gas (gas embolism), or foreign material. An embolism can cause partial or total blockage of blood flow in the affected vessel. Such a blockage (a vascular occlusion) may affect a part of the body distant from where the embolus originated. An embolism in which the embolus is a piece of thrombus is called a thromboembolism. Thrombosis, the process of thrombus formation, often leads to thromboembolism.
An embolism is usually a pathological event, i.e., accompanying illness or injury. Sometimes it is created intentionally for a therapeutic reason, such as to stop bleeding or to kill a cancerous tumor by stopping its blood supply. Such therapy is called embolization.
Since 1981 Lecompte has put his Lecompte manoeuvre in use. This is used with the REV (Réparation à l'Etage Ventriculaire). This surgery is like the Rastelli procedure, but with the use of the pulmonary artery without a conduit.
There are different types of embolism, some of which are listed below.
It was Bex who introduced in 1980 the possibility of aortic translocation. But Nikaidoh has put the procedure in practice in 1984. It results in an anatomical normal heart, even better than with an ASO, because also the cones are switched instead of only the arteries as with an ASO.
It has as contra-indication coronary anomalies.
Pulmonary artery sling is a rare condition in which the left pulmonary artery anomalously originates from a normally positioned right pulmonary artery. The left pulmonary artery arises anterior to the right main bronchus near its origin from the trachea, courses between the trachea and the esophagus and enters the left hilum. Symptoms include cyanosis, dyspnoea and apnoeic spells. It almost always requires surgical intervention. Rarely it is asymptomatic and is detected incidentally in asymptomatic adults.
In general, the treatment of PPH is derived from the treatment of pulmonary hypertension. The best treatment available is the combination of medical therapy and liver transplantation.
The ideal treatment for PPH management is that which can achieve pulmonary vasodilatation and smooth muscle relaxation without exacerbating systemic hypotension. Most of the therapies for PPH have been adapted from the primary pulmonary hypertension literature. Calcium channel blockers, b-blockers and nitrates have all been used – but the most potent and widely used aids are prostaglandin (and prostacyclin) analogs, phosphodiesterase inhibitors, nitric oxide and, most recently, endothelin receptor antagonists and agents capable of reversing the remodeling of pulmonary vasculature.
Inhaled nitric oxide vasodilates, decreasing pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) without affecting systemic artery pressure because it is rapidly inactivated by hemoglobin, and improves oxygenation by redistributing pulmonary blood flow to ventilated areas of lung. Inhaled nitric oxide has been used successfully to bridge patients through liver transplantation and the immediate perioperative period, but there are two significant drawbacks: it requires intubation and cannot be used for long periods of time due to methemoglobinemia.
Prostaglandin PGE1 (Alprostadil) binds G-protein linked cell surface receptors that activate adenylate cyclase to relax vascular smooth muscle. Prostacyclin – PGI2, an arachadonic acid derived lipid mediator (Epoprostenol, Flolan, Treprostenil) – is a vasodilator and, at the same time, the most potent inhibitor of platelet aggregation. More importantly, PGI2 (and not nitrous oxide) is also associated with an improvement in splanchnic perfusion and oxygenation. Epoprostenol and ilioprost (a more stable, longer acting variation) can and does successfully bridge for patients to transplant. Epoprostenol therapy can lower PAP by 29-46% and PVR by 21-71%., Ilioprost shows no evidence of generating tolerance, increases cardiac output and improves gas exchange while lowering PAP and PVR. A subset of patients does not respond to any therapy, likely having fixed vascular anatomic changes.
Phosphodiesterase inhibitors (PDE-i) have been employed with excellent results. It has been shown to reduce mean PAP by as much as 50%, though it prolongs bleeding time by inhibiting collagen-induced platelet aggregation. Another drug, Milrinone, a Type 3 PDE-i increases vascular smooth muscle adenosine-3,5-cyclic monophosphate concentrations to cause selective pulmonary vasodilation. Also, by causing the buildup of cAMP in the myocardium, Milrinone increases contractile force, heart rate and the extent of relaxation.
The newest generation in PPH pharmacy shows great promise. Bosentan is a nonspecific endothelin-receptor antagonist capable of neutralizing the most identifiable cirrhosis associated vasoconstrictor, safely and efficaciously improving oxygenation and PVR, especially in conjunction with sildenafil. Finally, where the high pressures and pulmonary tree irritations of PPH cause a medial thickening of the vessels (smooth muscle migration and hyperplasia), one can remove the cause –control the pressure, transplant the liver – yet those morphological changes persist, sometimes necessitating lung transplantation. Imatinib, designed to treat chronic myeloid leukemia, has been shown to reverse the pulmonary remodeling associated with PPH.
Preexisting diabetes mellitus of a pregnant mother is a risk factor that has been described for the fetus having TGV.
Following diagnosis, mean survival of patients with PPH is 15 months. The survival of those with cirrhosis is sharply curtailed by PPH but can be significantly extended by both medical therapy and liver transplantation, provided the patient remains eligible.
Eligibility for transplantation is generally related to mean pulmonary artery pressure (PAP). Given the fear that those PPH patients with high PAP will suffer right heart failure following the stress of post-transplant reperfusion or in the immediate perioperative period, patients are typically risk-stratified based on mean PAP. Indeed, the operation-related mortality rate is greater than 50% when pre-operative mean PAP values lie between 35 and 50 mm Hg; if mean PAP exceeds 40-45, transplantation is associated with a perioperative mortality of 70-80% (in those cases without preoperative medical therapy). Patients, then, are considered to have a high risk of perioperative death once their mean PAP exceeds 35 mm_Hg.
Survival is best inferred from published institutional experiences. At one institution, without treatment, 1-year survival was 46% and 5-year survival was 14%. With medical therapy, 1-year survival was 88% and 5-year survival was 55%. Survival at 5 years with medical therapy followed by liver transplantation was 67%. At another institution, of the 67 patients with PPH from 1652 total cirrhotics evaluated for transplant, half (34) were placed on the waiting list. Of these, 16 (48%) were transplanted at a time when 25% of all patients who underwent full evaluation received new livers, meaning the diagnosis of PPH made a patient twice as likely to be transplanted, once on the waiting list. Of those listed for transplant with PPH, 11 (33%) were eventually removed because of PPH, and 5 (15%) died on the waitlist. Of the 16 transplanted patients with PPH, 11 (69%) survived for more than a year after transplant, at a time when overall one-year survival in that center was 86.4%. The three year post-transplant survival for patients with PPH was 62.5% when it was 81.02% overall at this institution.
Lung infarction, also known as pulmonary infarction, occurs when an artery to the lung becomes blocked and part of the lung dies. It is most often caused by pulmonary embolism.
Bilharzial cor pulmonale is the condition of right sided heart failure secondary to fibrosis and sclerosis of the pulmonary artery branches. It results from shifting of the "Schistosoma haematobium" ova from the pelvic and vescial plexus to the pulmonary artery branches where they settle and produce granuloma and fibrosis.
Bilharzial cor pulmonale occurs in "Schistosoma mansoni", when the portal pressure rises more than the systemic pressure. So blood will pass from the portal circulation to the systemic circulation carrying "Schistosoma mansoni" ova to reach the lungs.
This condition leads to Pulmonary hypertension, right ventricular hypertrophy and failure.
The treatment of choice is percutaneous balloon valvuloplasty and is done when a resting peak gradient is seen to be >60mm Hg or a mean >40mm Hg is observed.