Helping Doctor Best
Mr. Frank, a 64-year old former postal worker was glad that "the worst was over". He was not very excited finding out that his mitral valve was leaking and that heart surgery was necessary. But it had to be done since he was already experiencing shortness of breath.
He felt very relieved now that surgery had been performed. His surgeon told him that everything went just fine and that he can consider himself the "proud owner" of a mechanical bileaflet valve. "Great" Mr. Frank thought to himself "what's there to be proud of? Well, at least I made it through surgery." Only 4 days later he was transferred back from the surgical ICU to the intermediate care unit.
Mr. Frank was now in his bed thinking of where he will spend his first vacation after successful surgery. Little did he know that his mood would suddenly change when Doctor Best, a cardiologist suddenly popped into the room dragging an echoscanner along.
"Mr. Frank, sorry to bother you but this is a routine echo scan. I want to see if everything is okay with your valve. I need to get some baseline measurements."
Doctor Best placed the transducer on his chest and suddenly his expression turned grim.
"Mr. Frank, there is something wrong, I am not quite sure what it is, but one question: do you have fever?"
"Well no....not that I know of. What's the problem?" asked Mr. Frank.
"You see - there is a mobile structure in your heart and I am not sure what it is."
Can you help Dr. Best?
Here are the images of Mr. Frank's heart: The mechanical mitral valve was functioning well, septal motion is abnormal and left ventricular function is reduced. But the most striking finding is a mobile structure attached to the subvalvular apparatus. But, what is the etiology of this mass?
What's the differential?
- Vegetation / endocarditis
- Benign tumor
- Malignant tumor
It is highly unusual that a thrombus forms on the subvalvular apparatus. It is also unlikely that the mass is a benign or malignant tumor since the patient was examined many times before. He even received a transeophaeal echo during surgery. So someone should have noticed a preexisting tumor. It is more likely that the mass is a vegetation even though one would expect the vegetation to be located on the valve itself. But certainly it is possible that endocarditis also affects the subvalvular apparatus. But Mr. Frank had no fever and his lab values did not point to infection. So, endocarditis is also rather unlikely.
So what’s next?
Well, Doctor Best simply paged Doctor Stich, the surgeon who performed the operation. He had the answer: The mass was simply residual tissue of the mitral valve apparatus that was hanging loose.
To understand the findings on the echocardiogram it is important to know how mitral valve surgery is performed. To preserve left ventricular function it is important to retain as much subvalvular tissue as possible. Thus, the surgeon does not resect the entire valve but leaves as much of the posterior leaflet in place as possible. This assures continuity between the subvalvular apparatus and the annulus of the mitral valve. Finally, loose chordae that might interfere with the prosthesis are removed.
In Mr. Frank’s case, Doctor Stich did not bother with a small loose portion of the subvalvular apparatus. Well, after all it is more a cosmetic problem and will certainly not lead to any problems for Mr. Frank.
So what's the key message?
Be familiar with surgical techniques. Not only will it help you to provide the information that surgeons need for operative planning, but it can explain structures that you encounter after surgery.
Mr. Frank was relieved to find out that nothing serious was wrong with his valve and was discharged 1 week later.
On a final note: Mr. Frank still needs follow up, not only for the structure but also for left ventricular function and dyssynchrony. But that is a different story that will be dealt with in an upcoming blog post. So stay tuned!
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