Cardiothoracic Surgery Expert Witness Advises on Failed Aortic Valve Replacement Surgery

A cardiothoracic surgery expert witness advises on a case involving an 80-year-old patient, located in Nebraska, who underwent an aortic valve replacement (Medtronic) that was met with some difficulty. The patient’s valve appeared to have a high gradient that was confirmed on a post operative cath lab evaluation. The patient returned to the OR and underwent removal of the first valve and an aortic root replacement with single vessel bypass grafting was performed. The patient’s recovery was met with significant coagulopathy and bleeding along with heart failure and generalized edema. The patient was sent to the ICU with an open chest and returned for a mediastinal washout with temporary dressing closure. Hepatorenal failure and multi-organ system failure ensued and life support was withdrawn after she developed massive acidosis which was thought to be link to an abdominal event.

Question(s) For Expert Witness

1. Please discuss your background working with Medtronic valve replacements.

2. Do you routinely treat patients similar to the one described in the case?

3. How do you prevent placing the wrong size valve requiring a corrective procedure?

4. Could this patient's complications have been avoided if the correct valve was placed initially, possibly avoiding the coagulopathic complications in the second procedure?

Expert Witness Response

I perform nearly 100 aortic valve replacements, 200 bypass procedures, and 50 miscellaneous open heart surgeries per year. I routinely use the Medtronic aortic valve as well as other valves. There are different ways to prevent patient prosthetic mismatch, including root enlargement and the use of stentless valves or enlargement of the aortic valve annulus to allow placement of a larger prosthesis than the initial annulus size would permit. Each option is associated with its own potential risks and difficulties. In addition, several valve types and implantation techniques can also help with the issue of small aortic valve annulus. Nonetheless, in this case, it's not clear to me based on the information provided if the high gradient is related to the fact that the valve that was placed initially was the "wrong" size or if there was another mechanism of obstruction. Redo surgery and exposure to another prolonged bypass and cross clamp times to perform the root replacement at the second round likely contributed to this patients coagulopathy and heart dysfunction with subsequent other organ injury. However, one needs to know more about the patient's anatomic and medical conditions to judge whether or not a more conservative and simple surgery (as was performed initially) was justified (sometimes a simpler surgery in an older fragile patient might be the proper choice) and to determine if those complications could have been avoided if the patient had undergone the root replacement from the beginning. Again, re-exposure to bypass and cross clamp likely contributed to the patient’s morbidity.