Aneurysms: Stenting & Surgery to Repair Abdominal Aortic Aneurysms
Guest: Dr. Jay Robison – Vascular Surgery
Host: Dr. Pam Morris – Cardiology
Dr. Pam Morris: Hi, I am Dr. Pam Morris and I am here today talking about aneurysms with Dr. Jay Robison, professor of surgery and vascular surgeon at the Medical University of South Carolina. Dr. Robison, are there any medical treatments once an aneurysm has been detected, or is surgery always necessary?
Dr. Jay Robison: Well, that is a good question, Pam. Right now, there are no good medical treatments that we know of. There are studies that are ongoing to kind of slow the rate of growth of these aneurysms but nothing really makes them shrink up or go away. When they get to a certain size and become dangerous, then they need to be repaired, usually with a surgical operation or with some intervention to re-channel the blood flow away from the wall of the aneurysm.
Dr. Pam Morris: I know we are moving more toward noninvasive or nonsurgical approaches. Are there any types, for example, of stenting procedures that are available for abdominal aortic aneurysms?
Dr. Jay Robison: Absolutely. For the last 50 years, the gold standard of treatment has been open repair which requires a big abdominal operation and temporary interruption of the blood flow to the legs and insertion of a replacement part, a graft made out of some prosthetic or Dacron, or something like that. That works great and the success rate is great, about 95 percent successful with no problems. That has been the standard for years and years.
Within the last 10 years, 15 years, there has been an increasing trend to repair some of these aneurysms with what we call stent grafting. That requires a more limited operation, usually performed through the groin, using various catheters and devices to be placed up inside the artery. The device springs open, kind of like an umbrella, and then unfurls like a windsock to seal the aneurysm off from the inside. It is kind of like putting an inner tube inside a flat tire so that there is no leak from the tire, and it works very well.
Dr. Pam Morris: Are there certain types of aneurysms that are more suitable for stent grafting than others?
Dr. Jay Robison: Most of the stent grafts that we have been able to perform have been on aneurysms below the renal artery area, infrarenal aneurysms, above the level of the groin and below the level of the kidney arteries. That seems to be the best anatomy that we have for stent grafting. Although, there is some increasing experience with preserving the blood flow to the kidneys with little side holes cut out of these stent grafts, or even the visceral arteries which go to the intestine, the kidney, not only the kidney but the stomach and the liver, to try and preserve those blood flows at the same time of sealing the aneurysm off. But, that is kind of in its infancy right now. One of these days, we may be there, be able to fix those aneurysms as well. Fortunately, 90 percent of abdominal aortic aneurysms are below the level of the kidney arteries and we can fix with stent grafting, if necessary.
Dr. Pam Morris: So, that would mean, then, that a fraction of patients are actually going on now to open surgical procedure?
Dr. Jay Robison: Interestingly, there is not very much difference in the outcomes between open surgery and stent grafting. Most patients gravitate toward stent grafting because it is an easier recovery time and less time in the hospital and they can get back to their life a lot more rapidly with stent grafting. But, if you look at the long term success rates, open repair is actually very good and there is no difference in long term survival with open surgery versus stent grafting. So, patients tend to opt for it. On the other hand, for young otherwise very healthy patients, the most durable form of repair is probably open repair still. Stent grafting has a definite advantage for patients that are higher risk for surgery, such as with bad heart disease, or bad lung disease or other risk factors that make them a high risk for an anesthetic or an open operation.
Dr. Pam Morris: Now, that reminds me, for example, when we talk about replacing a heart valve and we would prefer to use a mechanical or synthetic valve in younger patients because, again, of its durability. So, that would mean then that you are steering or helping to guide some of your younger patients, perhaps, toward an open repair rather than a stent graft?
Dr. Jay Robison: I think that is generally the case. Not very many patients under the age of 60 or 65 need to have an aneurysm repair. But, those that do probably would benefit in the long run, at least the way we understand it right now, from an open repair. But, certainly, for those patients that really want to get back to an active lifestyle and do not want to be in the hospital for a week to recover for three to four weeks afterwards, and want to get right back, then a stent graft does offer that option.
Dr. Pam Morris: Are there any of the issues regarding anti-platelet agents or blood thinners following the placement of an aortic stent graft, similar to what we see with stents in the coronary arteries?
Dr. Jay Robison: Well, fortunately, the aorta is a big blood vessel. So, maintaining patency of these stents and stent grafts, and even open repair, is not as much of an issue using blood thinners and anti-platelet agents. We do tend to use them as an adjunct because of the other comorbidities and risk factors though. There is no question that using some anti-platelet agents such as aspirin, a simple one, does seem to impact on long term benefit for patients. So, generally these patients are begun if they are not already on an anti-platelet such as aspirin, usually have an aspirin initiated at the time or after the repair.
Dr. Pam Morris: Do they require long term treatment with clopidagril or plavix, like the coronary patients?
Dr. Jay Robison: Generally not, not unless they have other indications for clopidagril.
Dr. Pam Morris: Does exercise or other risk factor control strategies play a long term role in management of patients who have had aneurysms?
Dr. Jay Robison: Only in the sense that it does reduce their morbidity and complications from other manifestations of atherosclerosis. As far as we know, exercise does not cause these aneurysms to grow. There is nothing that somebody can do to cause their aneurysm to burst by routine daily activities. They then bend, they can lift, they can drive. They can do all their normal daily activities when their aneurysm is not yet in need of repair. There is nothing that they are going to do to cause their aneurysm to grow. So, they can do all the normal activities and then exercise, that will reduce their problems with other manifestations of atherosclerosis as kind of a preventative health measure, sure.
Dr. Pam Morris: Dr. Robison, for each of the different procedures for repair of abdominal aortic aneurysm, what would be the projected recovery time? How long would a patient have to be in the hospital and then, perhaps, be away from work?
Dr. Jay Robison: Well, the usual time that people are in the hospital, say for an open repair, they usually come in the hospital on the day of their surgery. They are in the intensive care unit, usually overnight, and can usually get out of the hospital in about five days. It takes them a good three to four weeks, really, to get to feeling their old self again because their abdomen is sore and it takes them awhile to get their strength back and get back to their usual vigorous daily activities.
With a stent graft, usually people come in the same day. They have their surgery and they are out of the hospital in one to two days and usually back to their usual activities in about a week or so. The disadvantages for a stent graft are that patients usually have to come back for a follow up and a checkup and a CAT scan periodically, at least every year, more frequently during the first year. But, they do have to have a CT scan to make sure that once that aneurysm is sealed of initially that it stays sealed off overtime. An open repair, once it is fixed, it is fixed. We know that the long term durability is very good for open repair. So, the advantages of a stent graft are early recovery, early back to normal activities. The disadvantage of a stent graft is you have to keep coming back to the doctor for a long time to get checked.
Dr. Pam Morris: Well, Dr. Robison, thank you so much, today, for discussing the treatment of abdominal aortic aneurysms and I hope you will come back again.
Dr. Jay Robison: Thank you very much, Pam.
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