Questions and Answers
1.My patient is having aneurysm pain, but his aorta has not yet reached criterion dimensions. Should I be concerned about him? The answer is a resounding ?yes!? Remember that the dimensional criteria are specifically for asymptomatic patients. Any and all symptomatic aneurysms need to be resected because symptoms are a precursor to rupture. Aneurysm pain represents stretching irritation of the aortic adventitia, the adjacent chestwall or some other structure impinged by the expanding aneurysm. Even an aorta smaller than the criterion dimensions can rupture or dissect. Your patient is extremely concerning, and pre-emptive resection is needed. We recently were called on to review a case in which the patient had presented with typical pain of an ascending aortic aneurysm. His aorta was 5.0 cm. The caring team felt this was a bit too small for resection, neglecting the symptoms at presentation.The patient went on to rupture and die within 48hours. It cannot be overemphasized: these criteria are explicitly intended for asymptomatic patients; all symptomatic aneurysms need to be resected.
2.How can I tell if the pain is from the aneurysm or from other causes, such as musculoskeletal? This is a very important question, which is not always easy to answer, even in the most experienced hands. The patient usually has a good sense as to whether his pain is originating from muscles and joints. The clinician usually gets an additional sense on questioning. Is the pain influenced by motion or position? If so, it is probably musculoskeletal. Is there a history of lumbosacral spine disease or chronic lowback pain? If so, the symptoms may not be aortic in origin. Is the pain felt in the interscapular back? If so,this is almost certainly related to an extant thoracicaortic aneurysm. Perhaps the most important point to make is the following: presume that the pain is aortic in origin if no other cause can be conclusively established. This is the only posture that can prevent rupture.
3.How often should I image my patient?s aorta? We do feel that all patients with thoracic aortic aneurysm should be followed indefinitely. We usually image stable, asymptomatic patients about once every 2 years. Remember that the aneurysmal aorta grows at a relatively slow 1 mm per year. In case of new onset of symptoms, we image promptly, regardless of interval from the prior scan. For new patients, for whom we have only one size data point, we often image at short intervals until we get to know their aortic behavior. We may even image every 3 to 6 months for new patients with moderately large aortas. An important point to remember: compare the present scan not with the last prior scan but with the patient?s first scan. That is the way to detect growth. Many a patient has suffered because his scans were only compared with the last prior scan, and major growth went undetected. Comparing image to image is like watching your children grow; you don?t see growth on a day-to-day basis, but suddenly you find them grown full-size.
4.What diagnostic test should I use to follow patients? You can use either of the three quality imaging techniques currently available: echo, CT scan and MRI. If you use echo, remember that a standard transthoracic echo cannot see the distal ascending aorta, the aortic arch or the descending aorta with conclusive accuracy because of intervening air containing lung tissue. You must supplement periodically with CT scan or MRI, which can visualize the entire aorta. Regarding the choice between CT and MRI, this may depend on ease of availability and radiologic expertise in your particular environment. Both modalities can image the entire aorta extremely well. Elevated creatinine or contrast allergy may mitigate against CT and in favor of MRI. The need to evaluate complex aortic lesions in multiple imaging planes would also encourage MRI. Of course, in dwelling metallic foreign objects may make CT scan imperative, as MRI may be contraindicated.
5.What about my patient?s brothers, sisters and children? Should I recommend that they be evaluated? We feel that the data on familial inheritance are strong enough that the treating physician is obligated to recommend that family members be evaluated. Physicians of family members should be made aware that aneurysm disease has been diagnosed in the family. We recommend a CT scan for adult males and for females beyond child-bearing age. For children and for females of child-bearing age, we recommend echo of the ascending aorta and abdominal aorta. We hope soon to identify humoral markers or genetic aberrations that can be used for familial screening of the aneurysm trait.
6.Should I restrict my aneurysm patient?s activities? It is well known that serious weight lifters, at peaks of exertion, can elevate systolic arterial pressure to 300 mm Hg. This type of instantaneous hypertension is, of course, not prudent for aneurysm patients. We recommend continuing any and all aerobic activities, including running, swimming and bicycling. Regard-ing weight lifting, we recommend one half the body weight as a limit. We recommend against contact sports or those that might produce an abrupt physical impact, such as tackle football, snow skiing, waterskiing and horseback riding.
7.How about the new stent grafts? Should we intervene earlier now that those are available? Here is a word of caution about stent grafts. All three thoracic stent products previously in clinical trials are officially on FDA recall at the present time.The recent large, multicenter Eurostar study, due to a very high need for subsequent conventional surgery after abdominal aneurysm stent placement, questioned in their concluding statements the very efficacyand advisability of stent grafting. Endoleak, stent dislodgement and aneurysm expansion or rupture were disturbingly widespread in medium-term follow-up. We must remember that stents were designed to keep tissue from encroaching on the vessel lumen, not to keep the vessel from expanding. We must remember also that the natural history of the thoracic aorta is that it grows slowly and that hard end points (rupture,dissection and death) take years to be realized. For this reason, short-term stent studies are nearly meaningless. Long-term studies are needed. This new modality should be approached with caution. It should not, at this point, influence our overall intervention strategy.
