Though it resembles a coral, root system, or some other kind of growth, the above photo actually depicts a blood clot over 15cm wide in the near-perfect form of the right bronchial tree of a human lung, the Atlantic reported on Thursday. Even more uncomfortable is the revelation that it was not removed by medical staff, but in fact coughed up by a patient who was suffering from heart failure.
The photo was released in late November as part of the New England Journal of Medicine's Images in Clinical Medicine series. University of California at San Francisco doctors Gavitt A. Woodard and Georg M. Wieselthaler wrote that it came from their patient, a 36-year-old man who had long struggled with chronic heart failure.
The patient reportedly had a medical history including "heart failure with an ejection fraction of 20 per cent, bioprosthetic aortic-valve replacement for bicuspid aortic stenosis, endovascular stenting of an aortic aneurysm, and placement of a permanent pacemaker for complete heart block." When the patient was admitted to the hospital's intensive care unit, they hooked him up to a pump designed to help circulate blood throughout the body:
An Impella ventricular assist device was placed for management of acute heart failure, and a continuous heparin infusion was initiated for systemic anticoagulation. During the next week, the patient had episodes of small-volume hemoptysis, increasing respiratory distress, and increasing use of supplemental oxygen (up to 20 litres delivered through a high-flow nasal cannula). During an extreme bout of coughing, the patient spontaneously expectorated an intact cast of the right bronchial tree.
The patient was later extubated and "had no further episodes of hemoptysis," the doctors wrote, but a week later he unfortunately "died from complications of heart failure (volume overload and poor cardiac output) despite placement of the ventricular assist device."
Per the Atlantic, Wieselthaler said that the use of the pump requires anticoagulants to "make the blood thinner and prevent clots from forming," though that comes with the risk of uncontrolled internal bleeding. In this case, Wieselthaler told the magazine, blood leaving the heart to stock up on fresh oxygen in the circulatory system appears to have pooled in the right bronchial tree, clotted, and was then ejected by the patient in a jumbled form:
Once Wieselthaler and his team carefully unfurled the bundle and laid it out, they found that the architecture of the airways had been retained so perfectly that they were able to identify it as the right bronchial tree based solely on the number of branches and their alignment.
Wieselthaler added that one possible way the clot could have remained intact, rather than be broken up, was a high concentration of fibrinogen, a protein in blood plasma that helps form clots. The patient had an infection that both aggravated the heart failure and may have caused a buildup of fibrinogen in the blood, resulting in a more rubbery clot, he told the Atlantic.
Woodard told the magazine that it is additionally possible that the size of the clot actually may have contributed to its ejection, as it could have enabled the patient "to generate enough force from an entire right side of his thorax to push this up and out." (Gizmodo has reached out to Woodard to clear up some lingering questions, and we'll update this article if we hear back.)
It might seem a little like rubbernecking to gawk at the product of someone's medical misfortune, but even most doctors may never have the chance to see something like this. Though there are other conditions which can result in bronchial casts, including infections and asthmatic conditions or lymphatic-flow disorders that can cause buildups of mucus or lymph fluid respectively, Wieselthaler was emphatic that the size of this one is almost unprecedented.
"We were astonished," Wieselthaler told the Atlantic. "It's a curiosity you can't imagine — I mean, this is very, very, very rare."