Coronary Intervention with the Excimer Laser: Review of the Technology and Outcome Data

Excimer lasers are a class of ultraviolet (UV) gas lasers that produce high-energy, short-duration pulses of light. The term excimer is derived from “excited dimer,” referring to a short-lived molecule formed when an excited noble gas atom (such as argon, krypton, or xenon) combines with a halogen atom (such as fluorine or chlorine). These molecules exist only in an excited electronic state and rapidly dissociate after emitting ultraviolet photons, making excimer lasers highly efficient sources of coherent UV radiation.

Since their development in the 1970s, excimer lasers have become essential in a wide range of scientific, industrial, and medical applications due to their ability to deliver high peak power with excellent precision.

The aforementioned article by Rawlins et al, remains one of the best practical overviews of Excimer Laser Coronary Atherectomy (ELCA) despite it’s publishing over a decade ago. As such, it is advised that insights be interpreted alongside more recent literature. Medical Lasers as a treatment for vascular atherosclerosis began in the 1980s, however, soon evolved. Initially used for the treatment of critical limb ischaemia, what followed became decades of clinical trials, and most importantly, advancement in catheter technology and safer lasing techniques.

Excimer lasers are pulsed gas lasers that use a mixture of a rare gas and halogen as an active medium to generate pulses of short wavelength, high-energy ultraviolet light. The depth of laser penetration is directly related to its wavelength, with UV laser having less depth of penetration, less heat production and less unwanted tissue damage. These properties are precisely why Excimer Laser tissue ablation is the preferred method for intra-vascular interventional cardiology.

Excimer laser tissue ablation is mediated through three distinct mechanisms:

On 9th August 2023, Royal Papworth Hospital NHS Foundation Trust, Cambridge, UK, released a statement regarding the administering of Excimer Laser Coronary Atherectomy (ELCA) on a patient, the first of it’s kind in the United Kingdom.

Michael Bronze (63), a caretaker from Spalding, Lincolnshire first suffered a heart attack in 1999 after which he had stents fitted into his coronary arteries to widen them; thereby allowing blood to flow more freely. However in 2023, he was admitted to Royal Papworth Hospital NHS Foundation Trust following symptoms of breathlessness and arm pain. Mr Bronze was initially told heart bypass surgery was his only option, until he was offered a new procedure (ELCA), performed under local anaesthetic.

After inspection via a camera through his wrist, he had his stents lasered clean in approximately three hours by a cath lab team led by consultant cardiologist, Dr Stephen Hoole (See Image). Mr Bronze’s hospital visit was reduced to just one day, compared to a much lengthier stay often associated with cardiac surgery.

“ELCA offers the ability to vaporise obstructive tissue inside and outside the stent, enabling improved stent expansion and improving blood flow to downstream heart muscle, relieving angina as well as reducing the risk of future stent failure.”

Dr Stephen Hoole, Consultant Cardiologist, Royal Papworth Hospital NHS Foundation Trust.

The success of this ground-breaking treatment demonstrates the advantages of less-invasive procedures for re-narrowed stents compared to heart bypass surgery, the latter of which, as alluded to earlier would require a significant hospital stay and a greater amount of resources. It is hoped that similar treatments going forward will help alleviate the demand on NHS services and provide effective support for those suffering from heart-related disease and cardiovascular abnormalities.