Aortic Dissection

For the past four days since the President's husband had a heart operation, the newspaper headlines haven't waned in giving daily updates on his health condition. I wouldn't want to believe that dire medical bulletins sell newspapers, but from the looks of it, the publishers seem to have found a new marketing strategy.

Aortic dissection is truly one of those ailments you wouldn't wish even on your enemies. There are two types of aortic dissection (read more here), and I think what Mr. Arroyo had was the acute Type A aortic dissection.

He was wise to have the operation immediately after the diagnosis. Without surgical intervention, 90 percent of all patients with acute dissection will die within 2 weeks. Because of this, surgery has almost become mandatory. The surgery itself is not without risk --- the rate of dying from the operation has been estimated to range from 15 to 35 percent in many western countries (according to different studies) in spite of improved surgical techniques during the last 30 years.

In Japan, however, since 1999, in-hospital death rates has decreased to less than 20 percent. Operative death is defined as mortality within 30 days after surgery. Patients with acute type A aortic dissections are typically associated with high mortality rates due to complications encountered during the operation.

What happens in aortic dissection? A dissection is a tear in the aortic wall. The aorta is the largest artery of the body. It originates from the left ventricle of the heart and its chief function is to distribute oxygenated blood to the different parts of the body. Since the aorta is the artery nearest to the heart, it is expected that blood pressure here is greater than the rest of the arteries in the body. If the patient has the added problem of hypertension, you can imagine the shear forces that can immediately cause that damaged aorta to burst open, causing the patient to die in a short while. I think Mr. Arroyo had an unusually high blood pressure for his aorta to give up. As to the cause, it remains to be pondered. After all, he was on Easter vacation with his family in Baguio when he felt the pain. Ironic as it might seem, vacations can be stressful sometimes.

Why does the surgery take more than 8 hours? Because it is a delicate operation. If the aortic root itself is involved, surgeons do a composite replacement of the aortic valve and the ascending aorta. Otherwise, it is just SCR or supracommissural replacement of the ascending aorta. All patients are subjected to deep hypothermic circulatory arrest (DHA at less than 20 degrees Celsius) and antegrade selective cerebral perfusion (SCP) to protect the brain. The heart is then stopped with cold crystalloid cardioplegia.

The surgeons will then open the ascending aorta longitudinally, and the aortic segment including the aortic wall tear (the dissection) will be resected. Gelatin-resorcin-formaldehyde (GRF) glue will be applied to both the proximal and distal dissected ends of the false lumen. The glued stumps will then be strengthened with Teflon strips and the resected aorta replaced with a presealed woven Dacron graft.

In addition to correcting the aortic wall damage, the surgeon of Mr. Arroyo also did a triple bypass on him, making me suspect that a possible myocardial infarction or ischemia happened during the operation. According to medical literature available, this is considered a risk factor for in-hospital mortality conditions.

Some news headlines are misleading and rather than blame the news reporters, I wish to enlighten readers about these:

• FG Out of Danger; Rehab to Start - he is not out of danger yet. His condition might be stable but the first 30 days after the operation remains to be critical. I also do not think he is already up for active physical therapy. At most, passive exercises might be best for him. He still hooked on a respirator.



• Mike Wiggles Toes, Writes Notes - sounds very promising but how can someone who is sedated write notes? Even if he did, I can't see why his doctors will let him do this a mere 2 days after a high-risk operation. The wiggling of toes is more credible, and if true, shows a potential positive neurologic outcome.



• FG's Heart Surgery a Success - as I said, it is still too early to tell. Let us wait for 3 more weeks before coming up with a conclusion

Why the continuous dialysis? Because the heart was stopped during the operation, the kidneys suffered a malperfusion or a temporary period of inadequate blood supply. When this happens, the kidneys also suffer from a state of renal ischemia, making it unable to do its chief function of filtering wastes in the body.

Let us pray more he recovers from this ordeal.