What is Angioplasty and stenting?
‘Angioplasty’, has its origin from the two words ‘angios’ which refers to blood vessels, and ‘plasty’ which is a modification. Thus, angioplasty is a modification procedure on your existing vascular channels, which results in opening the block and securing the opened channel by using an artificial mesh called a stent. This helps in maintaining patency of the vessel
When it is performed for a vascular block in the heart, it is called, coronary angioplasty. It is also often referred to as PTCA (Percutaneous Transluminal Coronary Angioplasty) or PCI (Percutaneous Coronary Intervention), which are synonymous.
Why would you require an angioplasty?
Atherosclerosis is the most common cause for a block in your blood vessel. The percentage compromise on the blood flow is a deciding factor on interventional procedures like angioplasty.
Angioplasty with stenting is done in cases of stable or unstable angina, acute myocardial infarction or peripheral vascular occlusive diseases. Hence, it is not a specific procedure for the heart but also is often done for the limbs too, making it rather specific for a vascular compromise.
Atherosclerosis is an inflammatory process leading to deposition of fat laden macrophages (foam cells) and cholesterol crystals beneath the tunica intima of the blood vessels. It appears as a fatty streak in the beginning and gradually progresses to a plaque and later may enlarge and occlude a vessel especially when there is a plaque rupture that leads to clot formation. This process can result in a sudden episode of a vascular compromise, which is often presented as a multitude of symptoms described in a heart attack.
Atherosclerosis in its early stages may cause angina pectoris, and as described above may lead to acute events like myocardial infarction or heart attack in its severe forms. In the limbs this can cause acute limb ischemia and chronic limb ischaemia with dry gangrenous changes.
What are the signs and symptoms of Ischaemic heart disease and atherosclerosis?
The symptoms of a blocked blood vessel maybe as follows:
- Chest pain on exertion and relieved on rest (angina), unless it evolves into a serious complication like myocardial infarction or heart attack, when it is not relieved by rest, but stays for a period of time, as the heart muscle dies.
- Reduced exercise tolerance, and the ability to climb a hill or a staircase may be reduced in the beginning. In the advanced stages, it can decrease the ability to do normal household activities as well.
- Easy fatigability, nausea and breathlessness can be accompanying symptoms.
- When it comes to vascular blockade in the limbs, it can result in claudication pains and moreover, makes the patient tired easily with walking shorter distances, over a gradual period of time. These cases of peripheral vascular occlusive disease are however, handled by a vascular surgeon.
The clinical signs seen in ischaemic heart disease are:
- Tachycardia: an increased heart rate to compromise on the decreased blood supply by the occluded vessel.
- Arrhythmia: Irregular heart rhythm, due to ischaemia or decreased blood supply to the pacemaker system of the heart.
- Blood pressure changes: In early stages, there can be hypertension, which helps in improving the circulation and may cause damage to the vascular architecture. In advanced stages, low blood pressure may be seen due to a heart failure, wherein the muscular pump is damaged and a good force of contraction to pump blood all over the body cannot be achieved.
- Large, dilated heart with cardiomegaly: On examination of the heart, we may see an enlarged and dilated heart, which has failed, and some added heart sounds may be seen.
- Crepitations or crackles: On chest field auscultation, we might be able to find fine inspiratory crackling sounds. This is due to heart failure which has set in, resulting in a pulmonary oedema. This can cause the patient to develop a lot of breathing difficulties.
- Pitting oedema: On the dependent parts of the body (the ankles, when standing) may show evidence of fluid overload in the body due to pump failure and is reflected as bilateral pitting pedal oedema.
- Evidences of peripheral vascular diseases: Absent distal pulses like dorsalis pedis, posterior tibial etc. and prolonged capillary refill time and skin and nail changes in peripheral vascular occlusive disease.
- Signs of hypercholesterolemia: Xanthelasma on the face, xanthoma on the tendons and corneal arcus in the eye.
What are the types of diseases which can affect the coronaries?
The following are the diseases affecting the coronaries for which you may require a balloon angioplasty:
- Angina pectoris: This maybe stable or unstable or variant angina, which is basically a chest pain secondary to ischaemic heart disease. If left untreated may progress to a heart attack
- Myocardial Infarction or heart attack: This is the end result of an ischaemic cardiac event, and can cause loss of heart muscle and hence cause a heart failure and can be life threatening.
- Peripheral Vascular Occlusive Disease: This is the blockade of the blood vessels in the limbs, especially the lower limbs wherein blood supply is compromised due to atherosclerosis of the blood vessels.
Atherosclerosis and ischaemic heart disease is the pathophysiological process contributing to all these conditions.
How is coronary angioplasty performed?
The procedure is carried out under local anaesthesia. No general anaesthesia is required and hence you will be awake throughout the procedure. The steps involved are summarised as follows:
- Vascular access: This is gained via an incision in your groin, which is the most common site used. Other sites are the wrist and the arm.
- Insertion of catheter: A catheter is inserted via this vascular access and guided through, into the blocked blood vessel, by using a series of Xrays assisted by injecting dyes.
- Inserting the balloon and stent: A guide wire carrying the balloon is inserted into the catheter to reach the site of the block. It also carries the stent.
- Inflating the balloon and stent insertion: The balloon is then inflated at this site, which results in pushing the plaque materials causing the occlusion, to be pressed against the blood vessel walls. This leads to opening up of the vascular channel and the stent being kept in place.
- Deflating the balloon: The balloon is now deflated and flow through the blood vessel is ensured and the guide wire and the catheter are removed one after the other.
- Suturing the site of entry: The portal of entry, usually the groin is then sutured and haemostasis is achieved.
- Discharge: The procedure has very few complications. No long hospital stays unless any complications arise or if the case itself is slightly of a higher risk. If done for a case of angina alone, perhaps it may require observation for few hours to one day. However, decisions regarding hospital stays are made by taking into consideration, the status of the patient before, during and after the procedure.
Am I a good candidate for a percutaneous coronary intervention?
Well, the degree of the blockade of the blood vessel which is determined after an angiography, combined with the risk factors and chances of improvement in the overall quality of life are taken into consideration before proceeding for the treatment.
The indications for angioplasty are as follows:
- STEMI: ST segment elevation myocardial infarction
- NSTEMI: Non ST segment elevation myocardial infarction
- Stable or unstable angina
- High risk cases on cardiovascular risk assessment
Moreover, the risk assessment is done for every individual, and decision is taken for the procedure, because there is no general anesthesia required.
How will you be benefited with this procedure?
The advantages of doing an angioplasty are:
- Less time consuming and no requirement for general anaesthesia.
- Spontaneous reversal of symptoms of decreased heart muscle perfusion.
- It is a percutaneous procedure and hence no large incisions are required to carry out the procedure and everything is done using Xray imaging as a guide throughout the procedure.
- It uses a stent, which helps in preventing a re-stenosis of the blood vessel to prevent a future event. Nowadays, drug eluting stents which release some medicines are used and helps in better success rates in preventing the recurrence of the block.