Endovascular therapy for critical limb ischaemia: When is enough, enough?

Barry Katzen

We need to stop doing endovascular procedures for critical limb ischaemia patients when no measurable benefit is being seen and when the adverse event rate is increasing. Sometimes, reducing the level of amputation can be an acceptable outcome, writes Barry T Katzen. 

Critical limb ischaemia is increasing in frequency throughout the world, creating a true epidemic of increased limb salvage and mortality. It is estimated that the annual incidence for new cases is 500 to 100 million worldwide. Importantly, it is estimated by the American College of Cardiology that at one year, a 25% amputation rate can be expected, with an associated one-year mortality risk of 25%.

On the positive side, the development of numerous new endovascular technologies and more aggressive pioneering techniques, such as transpedal access, have broadened the range of revascularisation opportunities for many of these patients. As a result, it is hoped that a significant reduction in amputation rates and mortality can be achieved by wider utilisation of these procedures, and improved access for patients around the world.

With endovascular treatments, it is vital to try to get it right the first time. Some acute procedures can be staged to start with. It is important to pick the best procedure for the specific patient and anatomy, always using the team approach. Consider using improved endpoints in real time and always employ teams in the decision-making. Reported amputation free survival is 80–85% at one year, but this does not equate to a “cure” of critical limb ischaemia—amputation rates are increasing. It is also important to try to use objective endpoints of therapy to avoid repetitive procedures.

With regard to clinical evaluation, it is important to take into account the status of the patient: is the patient ambulatory? What is their level of activity? What comorbidities do they have? It is also important to ask the question, how will the patient benefit from therapy? Clinicians sometimes need to plan for staged procedures and set out the increasing risk and benefit of the procedures. They also have to take into account the cost and resources available. Significant amount of procedural cost frequently occurs at the end of a failed procedure; so in the end it all boils down to clinical judgement.

There are, however, patients in whom multiple procedures and technologies fail. It is important for operators to understand when a cycle of failure is developing, and where perhaps amputation might be the best solution for a patient, or reduction in level of amputation can be an acceptable solution. When understanding and managing failure, it is important to be cognisant of the fact that in critically ill patients that up to 80% of lifetime expenditures are made in the last 48 to 72 hours of life. This leads us to examine the question: what is the cost of failed treatments for those who have critical limb ischaemia? And, in those who have multiple successful procedures, what is that cost? Because endovascular therapy adds significant cost to patient care, it is imperative that we, as vascular specialists, use these resources with the highest degree of success.

So, when is enough, enough? There is no clearly defined answer. However, we need to stop doing procedures when no measurable benefit is being seen and when the adverse event rate is increasing. Again, it is important to stop and reconsider when the risk-benefit ratio is shifting in the wrong direction. Sometimes, reducing the level of amputation can be an acceptable outcome.

Hopefully, critical limb ischaemia will receive the attention it deserves from a public health standpoint and efforts to reduce amputation will mirror those to reduce stroke and acute myocardial infarction rates. We should not underestimate the cost of failure to the patient, since it may involve multiple failed procedures, increased cost, and even clinical worsening. In addition, as critical limb ischaemia therapy becomes increasingly used, there will be more scrutiny on costs and benefits will occur, it behoves us to take leadership in understanding costs and how they can be mitigated, before someone else does.

Barry T Katzen is founder and chief medical executive of Miami Cardiac & Vascular Institute, Miami, USA