Michael Ibrahim, MD, PhD, director of mitral and reconstructive valve surgery at Penn Presbyterian Medical Center, reviews mitral annular calcification, including definition, related complications, surgical options with case footage, and contemporary results.
Related Links: See Dr. Ibrahim's physician profile Good morning. My name is Michael Ibrahim. I'm the associate director of the metro valve program at penn. And today I'm gonna be talking to you about surgical results in Mac. Mac has been around since the dawn of civilization. This is a cat scan of an ancient Egyptian mummy showing infiltration of the analysts from Trigon Trigon with a classic appearance of Mac. We don't know the cause of death in this ancient Egyptian, but it just goes to show that this is a problem that we've been dealing with for a long time and well before we understood what it is, uh what is it? It is destructive. Classification of the fibrous mitral analyst has a prevalence of 8 to 15% with a marked increase in older patients and those with chronic kidney disease. It exists in up to a quarter of surgical patients but of course exist along a spectrum. This can be patchy infiltration of the analyst, which is really not a big problem to total invasion of the entire circumference of the mitral minus or the inter tribunal region, which is typically the region that is more commonly affected. The mechanisms are incompletely understood but include increased annual stress, abnormal calcium phosphate metabolism, which ties in with its association with chronic kidney dysfunction and congenital associations with various syndromes. It tends to be more common in women, especially in the post menopausal period. One of the reasons that surgeons get concerned about MAC is its association with certain catastrophic complications, including the invasion of the inter atrial groove region with tearing that can occur, allowing blood to enter into abnormal myocardial planes or even totally disrupt the entire thickness of the my korean with catastrophic bleeding. The approach to repairing these problems in the operating room generally involves re cross clamping, excising the metro analyst patch exclusion of the entire area and then mitral valve replacement once more even in the best of hands. This results in a high burden of mortality and morbidity. And since the first description of the surgical results of MAC bye Carpentier, the beginnings of mitral valve surgery, we've really evolved into several different strategies for dealing with MAC. The first is to leave it well alone. The respect strategy. This includes future placement around MAC as able or in repair cases can include oversized annual capacity going out with the typical animals. LTD debridement in replacement cases can be used, which I'll show you an example of. And another option in mitral repair with MAC is to perform asymmetric annual capacity where portions of the surgical um of the mitral annuals that are surgically approachable can be um uh can be reduced by annual capacity and the areas that are extensively destroyed with calcium. A left well alone. An alternative strategy is really the respect and reconstruct approach. This involves sharply removing or ultrasonic li de breeding. Um The MAC patch reconstruction of the analyst is often required. This is an especially attractive option in my opinion, in patients with M. A. D. Where that space is typically invaded with calcium. And this can result in a reconstructed analyst that that you know results in a new analyst that is free from calcium and can be then surgically operated on in terms of repair or replacement. Um There are various trans catheter approaches that can be used in MAC. This includes true mitral, trans catheter valve replacement and Sitra, which is surgical implantation of the mitral valve. Um really a tab a valve that is put in surgically. This can be done through minimally invasive approaches. I'll show you in a moment and then the alternative strategy is to get creative depicted here is a strategy which involves the excision of the mitral valve leaflets and really abandoning the native analysts um and placement of an inter atrial um mitral valve prosthesis typically with the aid of a pericardial or dacron patch. Uh This is a really reserved for cases with an extremely hostile micro um analysts and requires a good sized mitral prosthesis. So, and a good sized left atrium to allow for a good sized mitral prosthesis in in the atrium you will hear a loud ultrasonic noise as we begin the agreement of the mitral islands. In this case this is using a high frequency ultrasound device that the breed's calcium from the metro analysts to allow limited placement of sutures in portions that already um too hard to allow safe placement of a suture for mitral valve replacement. This is a complex operation that you know is is really best done in in in in centers that have experienced with this. And this is generally our approach for mitral valve replacement of MAC. And we found this to be doable in a wide range of severity of mitral annular calcification. Uh This is a case uh kindly shared with me by dr rob smith at the plano Heart hospital which involves a patient with severe MAC um in whom trans catheter mitral valve replacement was not an option due to concern for new ele bot obstruction. What you can see here is that robotically the the anterior leaflet of the mitral valve is excised. This reduces the risk of L. V. O. T. Obstruction. Um Then we size the mitral valve analysts and once that has been sized felt is brought up to um to reconstruct the the placement zone or the of the neo analysts if you like of the central valve. The felt really has several advantages. One is that it allows for a more atrial placement of the device and this reduces the risk of neo ele bot obstruction. And the second is that where there may arise small gaps where the rigid asymmetric mitral analyst has not completely sealed with the transgressed. The valve felt can can plug those small holes um and so you can see that the felt is put in circumferential e the size generally with the valve sizes to begin with to give an idea of its general size um and very few sutures are required. Um Generally about six futures. And the final sizing is done to confirm what it will look like At this point, any final alterations where we think gaps will arise. And of course Paradise Valley leaks can be can be sealed. And then a trans catheter SAPIEN three valve was brought in. You will see the commercial tab coming into view which provides an orientation of of you know where this should be implanted. And then really uh we deploy the valve very very carefully with good visualization, allowing for an excellent result in this case. The contemporary results of the surgical management of um of MAC vary very widely. This was a study of the sts database performed a few years ago, which looked at 2011 to 2017 version of the STS database, including 52,000 patients That underwent Mitral Valve replacement between 2011 2017. Um 18% had surgical NVR with in the presence of Mac. And again, you know important to bear in mind that that can be a focal calcium. It can be complete destructive annular calcification of the entire analyst or anything between those two extremes. What you can see is that there is an association with various um um comorbidities including media style radiation, um uh other surgery, chronic kidney disease. Uh and and other features that we have discussed. The mortality is certainly higher in patients 5.8% in the study, compared to 4.4% for non black patients. Um in in terms of Mitral Valve replacement, it increased the rate of important complications, including re intubation and acute kidney injury. And important centers that have performed less than 50 mitral valve replacements per year had significantly worse outcomes in this study. I think again, making the case for the complex nature of MacK requiring a tailored approach in the hands of, you know, experienced heart team. So in summary MAC itself portends a poor prognosis due to its association with several critical comorbidities. It also increases the risk at the time for surgical intervention. Various trans catheter, hybrid and open surgical approaches are now available for MAC, and the contemporary results are good, but the landscape will change as new options that respect the