Breathing life into the written-off
The endoventricular patch plasty is a cardiovascular procedure with promise, writes GOUTAM GHOSH.
THOUGH cardiologists have top-of-the-line drugs; have the coronary angioplasty to clear the coronary artery blocks; can insert a stent (an artificial channel) into a stenosed (blocked) artery, they sometimes have to ask the cardiac surgeon to correct the flaw. In many, the myocardial (heart muscle) cells die over time. These necrosed or fibrosed cells are deadweight to the healthy muscles, which then strain to pump blood.
The left ventricle (LV), which does the hardest work, gets its oxygenated blood through the left anterior descending artery the largest multi-branched vessel on the myocardium. When this vessel is blocked, the LV does not get its supplies. The heart then overworks itself and the fatigue leads to myocardial infarction, or heart attack. Over time, the cells of the myocardium could die and the ischemic area could spread. The heart loses its shape, and its inability to pump blood reaches a point where cardiologists throw up their hands and say, "Sorry! You need a transplant."
It is a matter of chance finding a tissue-matched cadaver heart; even after a transplant, none can promise longevity. So when a cardiologist throws up his hands, a typical heart failure patient will have to count his days. Not many cardiac surgeons attempt to attack the source of the problem the renegade LV. Bypassing the blocked arteries with harvested vein or mammary artery grafts, with or without cardiopulmonary bypass (CPB, the heart-lung machine), does not restore the damaged myocardium.
The Batista procedure (begun by R. Batista, Brazil) is to resect (cut remove) the infracted section of the LV and stitching together the viable flaps to reduce the volume so that the pumping efficiency (measured as "ejection fraction") can improve. In the Dor procedure (of Vincent Dor, Monaco), a circular patch is used to reduce the volume without resecting any part.
The endoventricular patch plasty (EVPP) done by Janardhana Reddy and his team at the Vijaya Heart Foundation, Vijaya Hospital, Chennai, brings hope to patients without hope. His approach is a variant of Dor's.
After the patient is placed under CPB, the heart stops as the machine takes over the patient's oxygenation-circulation cycle. The surgeon cuts into the LV through the lateral wall of the infracted portion.
For one such patient (see the photographs), after the median sternotomy (cutting open the breast bone), the exposed heart seemed like a throbbing mass of jelly. After cutting in, a huge blood clot was seen. This was removed. One edge of a polytetrafluoroethylene (PTFE) patch was stitched to the ventricular septum (the wall between the two ventricles). The other edges were sutured in the same manner and anchored to the wall of the LV. The patch was trimmed and the remaining edge was sandwiched between the incised LV flaps and stitched together.
The diseased dyskinetic heart, which was nearly double the size of a healthy one, had an ejection fraction of less than 20 per cent. (A healthy LV at rest ejects 60 to 70 per cent of the volume of blood entering from the left atrium). After the operation, the heart seemed more tightly packed. The diseased coronary artery had already been bypassed with grafts. The patient's heart waited to take over the CPB.
The advantage of grafts is that the myocardium tends to recover once the blood supply to it is restored. But no matter how well the job of a bypass done, the fibrosed portions of the heart can never recover.
Though the post-operative mortality is around three per cent, the success rate is impressive because most of these patients had been written off. Just as most of the 221 patients who have had EVPP done at the Vijaya Heart Foundation since 1997, the 60-year-old Manohar Lal Rathi of Chhindwara, Madhya Pradesh, happily shared his tale. Manohar Lal has been going for long walks since his Janardhana EVPP procedure and six grafts. But he admitted that he wouldn't have been around had his heart not been helped some 24 months ago.
What matters is many hopeless patients get a chance to live near-normally again. From being an end-stage Class IV `D' to Class II `B' patient. The question of "control" is absurd, as no doctor in his right mind will refuse to do what must be done just because control data are required for a publication. The trick lies in identifying the fibrosed sections and leaving them out when attaching the PTFE patch to reconstruct the LV. Another trick is in not damaging the ventricular spetum. The added hurdle is the superior skills needed, because the reconstructed volume lies below the patch and it vanishes from sight as the suturing progresses.
The procedure has not spread probably because not many trust their hands to give it s shot, and secondly not many are willing to translate their 3D knowledge of the LV to give it the skewed conical shape of a good one. And it has not spread because it is easy to raise the "scientific validity" issue; and easier still to throw up one's hands and say, "Sorry! You need a transplant."
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