Intravascular lithotripsy (IVL), which uses ultrasound shock waves to ‘crack’ highly calcified deposits and blockages within coronary arteries, was recently successfully performed for the first time in Africa.
The procedure was performed on a 79-year-old Gauteng patient, who had severe coronary artery disease (CAD) and had previously suffered a heart attack. It was undertaken by a team led by interventional cardiologists, Dr Chris Zambakides and Dr Jean-Paul Theron, in the cardiovascular centre’s catheterisation laboratory at Netcare Union Hospital in Alberton.
Zambakides and Theron said that the procedure enabled the team to successfully clear a way through the patient’s severely calcified and blocked coronary arteries, so that these could be successfully supported with stents that are used to support and treat diseased and narrowed arteries. “The team is most impressed with the results we were able to achieve with the new procedure. It will enable us to tackle even the most challenging of calcified coronary arteries, and reduces the risks associated with traditional coronary angioplasty and stenting in highly compromised cardiovascular disease patients,” Zambakides said.
“The patient was immensely pleased with the results of the procedure, which took some 90 minutes to complete, and says that he almost immediately felt relief from the severe chest pains, fatigue and other debilitating symptoms he was experiencing. Indeed, as we were leaving the theatre afterwards, he surprised us all by announcing that he felt ready to go home,” he added.
Zambakides explained that severely calcified and diseased coronary arteries can make coronary interventions such as traditional angioplasty and stenting considerably more difficult and significantly complicates the procedure. He says not only can this be associated with higher complication rates such as rupture but also with poorer long-term outcomes.
“Acutely it may be associated with stent under-expansion and in-stent restenosis (ISR), which is when a blocked artery that was opened up with angioplasty and stent becomes narrowed again. In this case, the patient had occlusions of between 70% and 90% in various coronary arteries.”
Zambakides says that due to the patient’s age and the presence of comorbidities, or additional medical conditions, surgery was not a viable option. Cracking the calcium with a high-pressure traditional angioplasty balloon was also ruled out in favour of the new ultrasound shock wave approach because of concerns of complications due to the large amounts of calcium deposits present.
“While rotablation, which involves the use of a tiny drill-like device, is suitable for grinding the calcium out of smaller vessels, it is extremely difficult to achieve the necessary pressure needed to break up severe calcifications in major coronary arteries during an angioplasty procedure,” he adds.
“The system involves the use of a special integrated balloon with electrodes attached that produce localised sonic pressure waves to ‘hammer’ at the calcium on the arterial wall, and breaks it up. After this, the IVL system’s integrated balloon is expanded, making placement of the stents considerably easier and safer in these patients. As the technology safely selects and fractures the calcium, any trauma to the soft tissue is minimised.”
The procedure is ideal for patients with heavily calcified lesions, particularly where these deposits are thick and subintimal. “The severity of calcification is not always obvious but may only be visible once you perform an angioplasty. In such an instance, instead of persevering with the angioplasty stenting procedure, we recommend now rather switching to the Shockwave IVL procedure in these types of patients, which make up about 5% of those seen by cardiologists.”
To date, more than 3,000 of these procedures have been performed globally, with the bulk having been undertaken in Europe and New Zealand, in patients between the ages of 60 and 80 years, and with a claimed success rate of 99%.