Valley Heart & Vascular Institute - Complex, Aortic Arch and Re-operative Aneurysm Surgery
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Complex, Aortic Arch and Re-operative
Aneurysm Surgery

Peninsula-style replacement of the transverse aortic arch.
Peninsula-style replacement of the transverse aortic arch.

Proximal Aortic Arch Surgery

Primary aortic arch aneurysm is rare (link here for more information), but ascending aneurysms that involve only the first portion, or the lesser curve (underbelly) of the aortic arch are quite common. These are usually ascending aneurysms that taper in size as they approach the arch. In fact, approximately 75% of all BAV-associated aneurysms involve this 'proximal' arch. The classical treatment for this area of involvement used to be a substantial source of morbidity in aortic surgery: the 'old school' approach was to cool the patient to 18 degrees Celsius (using the heart-lung machine), pack the head in ice, and then completely turn off life-support, including the heart-lung machine. This is called 'circulatory arrest', and, with the clock ticking (30-45 minutes maximum) and literally zero blood flow anywhere in the body, the aortic arch is opened without a clamp in place, a portion of the arch is excised, and a synthetic (polyester) graft is sewn to the open aortic arch. At Valley, we employ a technique that has been associated with the best neurologic outcomes (lowest stroke rates), wherein we never turn off the blood flow to the brain, called 'regional antegrade cerebral perfusion'. With this method, the patient is cooled much less dramatically (to 28 degrees Celsius), which decreases the inflammation and tendency for the blood to remain very thin after 'going cold'. While blood flow to the body (not the brain) is typically interrupted for approximately 20 minutes on average, the brain is receiving its normal amount of blood flow, and we monitor the brain oxygen levels during this time period and make adjustments as needed. Patients tolerate this technique very well, as evidenced by our excellent outcomes. Most centers that employ this technique do so through a separate incision below the right collar-bone, however, recently we have been promoting a technique that allows us to accomplish the task by sewing a synthetic graft onto an aortic arch vessel called the innominate artery within the chest. This eliminates the need for a separate incision, and we hope to publish on the technique soon. It has become important to identify when the proximal arch is involved, as failure to address this portion of the aneurysm (which often is smaller than the primary aneurysm, usually the ascending) may leave abnormal aortic tissue behind that may grow large enough (become more aneurysmal) to require yet another aneurysm operation in the future. Fortunately, our sophisticated imaging techniques provide us with detailed 3-D information about this part of the aortic arch so that appropriate treatment can be instituted.

Re-operative Aortic Surgery

Sometimes, thoracic aneurysm becomes apparent in patients who have previously undergone open-heart surgery. This could often be suggested by an echocardiogram (cardiac ultrasound) obtained in the doctor’s office. Most often (but not always), these are patients who have undergone previous aortic valve surgery, usually with a diagnosis of Bicuspid Aortic Valve (BAV). Sometimes this occurs in patients who have had previous aortic aneurysm surgery, if a slightly aneurysmal segment was left behind. It is especially important to risk-stratify patients with aneurysm and prior heart surgery, since aortic dissection in this setting is particularly treacherous to deal with operatively: scar tissue from previous surgery makes emergency access to the heart very challenging and mortality may be quite higher. Fortunately, elective re-operations for thoracic aneurysm are not only feasible, but have been shown to be as safe as primary operations in our hands. We use the same risk stratification tools as for primary aneurysm, and all forms of thoracic aneurysm can be handled in a re-do setting, including aortic root and arch surgery.

Other complex scenarios

When aneurysm is present concomitantly with other heart problems, combined surgery may be indicated, including valve repair or replacement, coronary bypass, and Maze surgery for atrial fibrillation, also with excellent results. In addition, aneurysm surgery in elderly patients, even well into their 80's, has been performed at Valley with the same safety profile as our younger patients. We do not decline patients based on age alone, and would much prefer elective aneurysm surgery to emergency surgery in this patient sub-population. Elderly patients with aneurysm may have additional risk for dissection or rupture due to more fragile tissues in general, and certain conditions that are much more common in the aging population (i.e. constipation, which can be a very important risk factor for rupture).

For more information, contact Leanne Scaglione, R.N., MSN, APN-BC, Coordinator for the Thoracic Aneurysm Surveillance Program, at 201-447-8398.

 
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