Not All Minimally Invasive Procedures Are Created Equal

Not All Minimally Invasive Procedures Are Created Equal
Parvathy Hariharan

This article has been authored by Kevin Kallmes, CEO of Nested Knowledge.

The invention and spread of endovascular procedures–minimally invasive interventions where physicians treat vascular disease by insert devices through the patient’s circulatory system–came with the promise of saving lives and revolutionizing surgical care. While open surgeries for vascular diseases are certainly declining in favor of minimally invasive procedures, the patient benefits of these procedures have recently been called into question. In fact, the efficacy of one of the most common vascular procedures–indeed, one of the most common procedures in the US overall–showed no benefit for stents over cholesterol-lowering drugs in patients with stable heart disease. The ISCHEMIA trial, the largest-ever study of stenting for coronary artery disease, has caused a public debate and deep examination of procedures that, at best, may offer incremental benefits. Despite being performed on nearly 1 million Americans every year, this supposed endovascular revolution in cardiovascular health is effectively delivering no benefit at extraordinary cost. With global spending on stents exceeding $6 billion, patients are right to question whether treating cardiovascular disease endovascularly is effective, and whether the minimally invasive revolution is, in fact, delivering on its promise. However, I think that a better question than “do minimally invasive procedures work” is “which minimally invasive procedures have major, not incremental, benefits, and at what cost?”

With the media focus around the failings of an elective procedure for a stable disease, I think that far too little attention has been given to an emergency procedure that has shown incredible patient benefits, which in turn limits the attention given by policymakers toward expanding access to this acute intervention that can help patients suffering from terrifying and sudden strokes. Until 2015, the best therapy physicians could give stroke victims was a “clot-busting” medication, which was somewhat effective but very limited in when it could be used–less than 5% of patients actually received it. That meant that modern medicine had no real assistance to offer the majority of patients suffering from strokes–until a minimally invasive therapy, “mechanical thrombectomy,” was developed.

Like stenting, thrombectomy uses catheters inserted into patients’ arteries and then snaked to the location of a blockage. However, unlike stable heart disease, where physicians push open narrowed vessels with stents and balloons, strokes involve clots that fill the entire artery and cut off blood flow to the brain. In thrombectomy, entire clots are sucked out through the catheters, restoring bloodflow to the brain. While this has to be done rapidly, given that 2 million neurons die every minute during a stroke, the benefits of this procedure up to 24 hours after a stroke have been demonstrated in a randomized trial. Crucially, thrombectomy has benefits that speak for themselves across five randomized trials: Over 70% of patients had their clots successfully removed, and 46% of patients had good neurological outcomes (compared to just 26.5% with previous best therapy).

Not only does the procedure show benefits, it also continues to improve. The single publication that drew me to thrombectomy–and that inspired me to join a company developing a thrombectomy device–gave a simple review of the benefits of using balloon catheters. Balloon catheters are used to navigate from patients’ femoral arteries to their brains and temporarily stop bloodflow so that clots can be more effectively sucked out, and across thousands of patients had the following benefits even compared to existing thrombectomy techniques:

  • 2X the odds of getting the clot out on the first try
  • 1.8X the odds of good neurological outcome
  • Half the rate of mortality

Any one of these three benefits should make balloon catheters a wonderful example of how minimally invasive procedures can save lives, improve patient outcomes, and address a major and terrifying disease. Even beyond this, the savings to society caused by the reduced costs of long-term disability care has been estimated at four times the costs associated with the procedure, meaning that thrombectomy potentially has net savings on healthcare costs.

Strangely, there is very little press surrounding balloon catheters for thrombectomy. If ISCHEMIA had shown that stents not only reduce mortality but rescue brain matter and save money in total, it would have been dramatic news of an amazing therapy, but the evidence on thrombectomy in general and balloon catheters specifically is essentially overlooked. Even worse, stroke care depends on establishing complex systems of response to ensure that patients are brought to skilled interventionalists as fast as possible, and a “thrombectomy suite” with all the proper imaging technologies are ready to treat patients.

Recommendations from the American Stroke Association (ASA) show the pressing need for telemedicine, community and emergency responder education, and even implement mobile stroke units for early imaging, all to ensure rapid treatment. But most of all, the ASA calls for an expansion of hospitals capable of thrombectomy so they include more than the current <300 centers, nearly 80% of which are in urban environments in developed countries. We need more interventionalists capable of completing thrombectomies, deployed to hundreds more hospitals as the population ages and stroke deficits balloon to cost society over $240 billion in the US alone by 2030. We need greater adoption of best tools–like balloon catheters–to ensure that we optimize patient outcomes. Most of all, though, this example shows that we need better communication, publicly, about which minimally invasive procedures benefit patients the most, so we can make informed decisions not only on which therapies to undergo as individuals but how to invest in the future of medical care. Otherwise, we risk throwing good money after bad on elective procedures while leading causes of death (stroke is #5) and preventable disability (stroke is #1) continue to afflict our society.