What is Advanced Angioplasty Procedure?
All over the world the most common and problematic heart disease at present is coronary artery disease which means blockages developing in the blood vessels of the heart. We all have three blood vessels which supply blood and nutrients to the heart muscle continuously so that heart can perform its function efficiently. Atherosclerosis is the disease process which causes accumulation of cholesterol and inflammatory cells in the inner layer of blood vessels of heart and brain leading to heart attack and stroke. This is due to either inadequate control of risk factors like hypertension, diabetes mellitus, dyslipidemia, obesity, or improper life style related factors like smoking, stress, obstructive sleep apnoea, sleep disorders and unhealthy dietary habits.
Our heart has a high degree of compensatory process so that symptoms like chest pain, breathlessness do not develop until the blockages in the blood vessels reach more than 70% severity. In diabetics and older age people because of neuropathy symptoms develop only after the blockages reach 90% severity. When the blockages suddenly rupture (plaque rupture) the blood clots over the preexisting blockage and leads to 100% occlusion which is the reason for heart attack. In order to diagnose the disease earlier we need to be proactive and undergo regular periodic health checkups including ECG, Echocardiogram and Treadmill test (stress ECG). To prevent the disease from developing we need to lead a healthy life style and if risk factors are present we need to control them with medications appropriately.
Coronary angiogram is a test to identify the blockages in the blood vessels of the heart, it takes 15-20 minutes usually for the test procedure and the patient has to stay in the hospital for further 4 hours for observation. If the blockage is more than 70% medications will not work and we need the treatment procedure called angioplasty (stent treatment). Angioplasty can be categorized as straight forward or advanced procedure.
Nearly 80% of the angioplasty procedures are straight forward, which normally takes 45 minutes to 1 hour for the procedure and totally 2-3 days stay in the hospital. Whereas in tertian patients the blockages are complex lesion which will require advanced expertise from interventional cardiologists, cathlab team, additional hardwares and intra coronary imaging for a safe and durable procedure. This type of complex lesions are present in post bypass surgery patients, calcified lesions in old age, chronic total occlusion, bifurcation lesions, left main lesions, chronic kidney disease patients and severe LV dysfunction patients.
In certain patients apart from cholesterol blockage calcium also starts depositing leading to very hard plaques and stent cannot be deployed or expanded. These patients in the past were sent for bypass surgery. But now calcium can be modified using many additional interventional procedures like Rotablation, Intravascular shock wave lithotripsy balloons (IVL balloon), Cutting balloons, Double layered NC balloons. Rotablation is a technique where a diamond coated small conical shaped the burr rotates inside the blood vessels (1,60,000 to 2,00,000 RPM) and shaves the calcium into small pieces (< 7 microns) which is washed away into the micro circulation. IVL balloon is a new technology where the balloon emits shock waves which makes cracks in the calcified lesion and allow the stent to expand.
In left main lesion and bifurcation lesions needing a double stent technique intra coronary imaging either Intravascular Ultrasound (IVUS) or Optical Coherence Tomography (OCT) will help in understanding the structure and distribution of blockages inside the blood vessels. These imaging catheters help in visualizing the inside of the plaques as live images. This helps in optimizing the stenting procedure leading to good long term outcomes.
In chronic kidney disease patients it is better to avoid injection of iodine contrast to visualize the coronary arteries during the procedure. In recent times we do ultra-low volume contrast angioplasty using IVUS techniques, so that further kidney damage due to contrast is avoided.
In chronic total occlusion lesions the blockage develops slowly and reaches 100% as a hard plaque. Since the lesion is total and hard additional special CTO wires with hard tip load are needed to penetrate lesion. Sometimes the wire is passed backward through small collateral vessels which is called retrograde technique to open the blood vessel blockages. In certain CTO patients laser energy is utilized to penetrate the uncrossable lesions. In patients with heart attack and cardiogenic shock where the blood pressure is very low, high risk complex angioplasty is performed after initiating Mechanical Circulatory Support (MCS) devices in the form of VA ECMO or IMPELLA pump device. This is also utilized in chronic severe LV dysfunction patients who need angioplasty procedures. Although these procedures lead to additional cost they help to avoid bypass surgery for patients who are at higher risk for surgery. It should be emphasized that many patients will still need bypass surgery because of other medical reasons.