Thrombolysis

Thrombolysis

By Dr.Ravindra Patil

Blood is a magical organ of our body which keeps flowing throughout our body through arteries and veins all our life. It carries oxygen from the lungs to all the tissues needing it and carries carbon dioxide back to the lungs. It carries nutrition to every cell of the body and carries waste products from all tissues and organs to the kidney to be excreted. This is what we learn in high school science class.

While in school, we all injure ourselves. Our skin may be torn and we bleed. But our magical blood clots and stops further bleeding. We all have experienced this.

The magic of healthy people’s blood is, it clots only when there is an injury and we bleed and further blood loss is prevented by clotting. In healthy people, the blood never clots inside arteries, veins or the heart. It always stays in a liquid state. And as has been mentioned our blood does the supply chain work of providing O2 and nutrients and flushing out waste products and CO2. If blood suddenly stops flowing because of a clot, the organs affected will first be starved of oxygen, and may die in a very short while.

If the organs so affected are the brain or the heart, the person will die!

So, the blood must keep flowing at any cost.

Table of Contents

Thrombosis and Embolism

However, on some occasions because of different pre disease factors, blood clots inside a blood vessel. This is known as thrombosis. These clots sometimes break, dislodge, and are carried to distant portions of the circulatory system, where they get stuck, and again block the blood supply beyond. This is known as embolism. Sometimes both thrombosis and embolism occur together, and then it is known as a thrombo-embolic event. If a clot forms in a vein and breaks loose, it will be carried to the arteries of the lungs and block them. This is known as pulmonary embolism and this is also a very serious life threatening condition. In all the above cases, a blood clot has occurred inside the arteries of the human body, which is starving the organs being supplied by that artery, and the person is very seriously ill if the arteries with the blood clot supply blood to the heart or the brain. All other organs are equally affected if their blood supply is blocked, but a block in the blood supply of the heart or the brain may cause immediate death. Thrombolysis in stroke is one of the best treatments for brain stroke. Clot in a brain artery results in an acute disease known as Cerebrovascular Stroke or Brain Stroke. Clot in a heart artery results in an acute disease known as Myocardial Infarction or Heart Attack. Clot in the pulmonary arteries is known as Pulmonary Embolism.

Thrombolysis

In simple words, thrombolysis [also known as thrombolytic therapy] is a treatment to dissolve dangerous clots in blood vessels, improve blood flow, and prevent damage to tissues and organs. Thrombolysis is done by the injection of clot-dissolving drugs through an intravenous (IV) line or through a long catheter that delivers drugs directly to the site of the blockage. It also may also be done by using a long catheter with a mechanical device attached to the tip that either removes the clot or physically breaks it up.

Thrombolysis procedure is often used as an emergency treatment to dissolve blood clots that form in arteries feeding the heart and brain — the main cause of heart attacks and ischemic strokes — and in the arteries of the lungs (acute pulmonary embolism).

Thrombolysis procedure is also used to treat blood clots in the following areas:

  • Inside veins: it is known as deep vein thrombosis (DVT). These are clots in the veins of legs, pelvic area, and upper extremities; if left untreated, pieces of the clot can break off and travel to an artery in the lungs, resulting in an acute pulmonary embolism.
  • Inside Bypass Grafts: these are clots formed in veins used in heart bypass surgeries, done for the treatment of a heart attack. These veins are harvested from the patient’s legs. This may lead to a second heart attack.
  • Inside Dialysis Catheters: these are lifesaving tubes inserted inside the neck veins of patients who need dialysis very often. A clot inside such a tube means the patient cannot be dialysed and this is a very serious condition.

If a blood clot is determined to be life threatening, thrombolysis may be an option if initiated as soon as possible — ideally within one to two hours — after the onset of symptoms of a heart attack, stroke, or pulmonary embolism (once a diagnosis has been made).

Different Thrombolysis Medications

The most commonly used clot-busting drugs — also known as thrombolytic agents or thrombolysis injections — include:

  • Eminase (anistreplase)
  • Retavase (reteplase)
  • Streptase (streptokinase, kabikinase)
  • t-PA (class of drugs that includes Activase)
  • TNKase (tenecteplase)
  • Abbokinase, Kinlytic (rokinase)

Depending on the circumstances, a doctor may choose to inject clot-busting drugs into the access site through a catheter. More often, however, doctors insert a longer catheter into the blood vessel and guide it near the blood clot to deliver medications directly to the clot.

During both types of thrombolysis, doctors use radiologic imaging to see if the blood clot is dissolving. If the clot is relatively small, the process may take several hours. But treatment for a severe blockage may be necessary for several days.

Thrombolysis Contraindications

Although thrombolysis can safely and effectively improve blood flow and relieve or eliminate symptoms in many patients without the need for more invasive surgery, it can’t be done in the following cases:

  • High blood pressure
  • Active bleeding or severe blood loss
  • Haemorrhagic stroke from bleeding in the brain
  • Severe kidney disease
  • Recent surgery
  • In pregnancy
  • In advanced age patients

Besides risk of serious internal bleeding, other possible risks of thrombolysis include:

  • Bruising or bleeding at the access site
  • Damage to the blood vessel
  • Migration of the blood clot to another part of vascular system
  • Kidney damage

The most serious possible complication is intracranial bleeding, but it is rare.

Prognosis after Thrombolysis

Although thrombolysis is usually successful, the treatment is not able to dissolve the blood clot in up to 25% of patients. Another 12% of patients subsequently redevelop the clot or blockage in the blood vessel.

In addition, thrombolysis alone — even when successful — cannot treat tissue that has already been damaged by compromised blood circulation. So, further treatment may be needed.

Thrombolysis in stroke

In advanced brain treatment hospitals like Samarth Neuro and Superspeciality Hospital of Miraj, thrombolysis is done in stroke patients in a very special manner. As soon as the hospital receives information about an incoming stroke patient, the Emergency Room and the CT Scan room are kept ready. The patient is transferred on arrival to the CT scan room and brain CT is done. If a blood clot in brain is detected, immediate treatment with Recombinant Tissue Plasminogen Activator [rtPA] is immediately begun and the patient is transferred to the ICU for continuous close monitoring.

If the patient has arrived in the “GOLDEN HOUR” or the first 60 minutes after a stroke, it is likely that the patient will recover fully from the stroke in a very short time.