Are Mini-Strokes And Cognitive Decline An Acceptable Cost Of Bypass Surgery?

PostopDelirium2I first heard the terms “bypass brain” and “pump head” from this article:

‘Bypass Brain’: How Surgery May Affect Mental Acuity, Wall Street Journal, June 2008

Cognitive damage from heart bypass surgery, a condition dubbed “pump head” or “bypass brain,” has long been recognized by doctors, even if they seldom warn patients about it.

Symptoms include short-term memory loss, slowed responses, trouble concentrating and emotional instability. In a landmark study published in the New England Journal of Medicine in 2001*, researchers at Duke University Medical Center tested 261 patients before and after bypass surgery and found that 53% of them had significant cognitive decline when they were discharged — and 42% still suffered from it five years later.

One explanation is that when a patient’s blood is pumped through a heart-lung machine during bypass, tiny air bubbles, fat globules and other particles may enter the bloodstream. The pump can also damage platelets, which form clumps, and clamping the aorta loosens bits of plaque. That debris can travel to the brain and clog tiny capillaries, forming microscopic strokes.

What if you don’t use a blood pump during surgery? It doesn’t seem to make a difference:

But studies have found that cognitive decline is just as common five years later in patients who had on-pump or off-pump bypasses.

Here’s the conclusion from that highly-cited NEJM study:

CONCLUSIONS: These results confirm the relatively high prevalence and persistence of cognitive decline after CABG and suggest a pattern of early improvement followed by a later decline that is predicted by the presence of early postoperative cognitive decline. Interventions to prevent or reduce short- and long-term cognitive decline after cardiac surgery are warranted.

I went looking to see if it’s still a problem. This review from a few months ago says it’s still a problem, and it’s getting worse:

Cerebral Dysfunction After Coronary Artery Bypass Surgery, Journal of Anesthesia, April 2014

Cerebral dysfunction after cardiac surgery remains a devastating complication and is growing in importance with our aging populations.

5 thoughts on “Are Mini-Strokes And Cognitive Decline An Acceptable Cost Of Bypass Surgery?

  1. Bix Post author

    I feel uncomfortable writing these posts. I’m sure people facing surgery think, “What choice do I have?” The stress of that time must be excruciating. Maybe that’s why surgeons don’t communicate, or don’t fully communicate, these risks. But … maybe that’s why we should talk about these risks way before someone is thrust into this position.

  2. Melinda

    I don’t know–if death is the alternative, maybe it’s worth the risk. My Mom had open-heart surgery w/ a pump and her body chilled down to some ungodly temperature, and fortunately, she went on pretty well for another 10 years or so. Guess it’s the luck of the draw. But I also thought doctors were required legally to scare the shit out of you by telling you all the possible awful outcomes…. Is that not true?

  3. Melinda

    I do know, from various friends, that open-heart surgery usually results in deep depression for a while afterward, and no one seems to know why. I’m not sure if it’s psychological or physiological.

  4. Bix Post author

    After Bill Clinton’s bypass surgery in 2004, and stents in 2010, he changed his diet to mostly vegan, lost weight, and improved his health. Had he made these changes earlier in life, he could have avoided these surgeries and their attendant risks

    Why not make the changes before something happens?


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