Total Arterial Revascularisation Bypass Surgery on Beating Heart with a LIMA-RIMA or Radial Y conduit

The LIMA-RIMA procedure is relatively new in the UAE.

"See how it's pulsing?" asks the heart surgeon, holding something that resembles two turkey bacon strips with crispy edges stitched together to make an inverted Y. "It" is a new artery, made up of the Left Internal Mammary Artery (LIMA) and the Right Internal Mammary Artery (RIMA), to supply blood to blocked arteries surrounding the heart. Called a Y composite conduit, it pulses with blood of the beating heart.

Dr Girish Chandra Varma, the then chief cardiac surgeon at NMC Specialty Hospital, Dubai, is performing a procedure called the Total Arterial Revascularisation Bypass Surgery on Beating Heart with a LIMA-RIMA or Radial Y conduit on a 51-year old man, who is a patient at Belhoul Specialty Hospital. The procedure is relatively new in the UAE. Although a few hospitals and surgeons claim to do the procedure regularly, Dr Varma was the first to announce the feat here in February 2006.

 The patient who suffers from chest pain during exertion, is his second patient in the UAE to undergo the LIMA-RIMA Y bypass surgery on a beating heart. He was referred to Dr Varma from his hospital in Abu Dhabi when doctors discovered his condition could not be solved by a standard angioplasty because the blockages were longer than the angioplasty balloon. Dr Varma says the patient is a suitable candidate for the LIMA-RIMA Y procedure as he is young and likely to fully benefit from the procedure. He says he prefers this procedure to conventional bypass surgery for many reasons: the use of LIMA-RIMA removes the likelihood of future fat deposits on the new artery, and performing it while the heart is beating removes the risk of damage to the heart, kidneys and brain associated with using the heart-lung machine. "The procedure might be risky and difficult, but the long-term benefits are worth it," he adds.

The procedure begins at 10:45am, when Dr Varma opens the chest, cutting the chest bone, or sternum, with a special saw. A chest spreader keeps both sides apart, exposing the beating heart. Part of the lungs can be seen, quivering with every heartbeat. Using the scalpel and cauterising the edges, he slowly detaches the LIMA, which runs from the top of the chest to the base, until it hangs loose from the chest wall. He cuts the artery at the bottom. Dr Varma shifts to the RIMA. The process is primarily the same, except that this time, he cuts a section of the artery out. The next step is to suture part of the RIMA to the LIMA forming a Y-shaped conduit, the turkey-bacon strip look alike. The whole process has taken the surgical team three hours.

Now the bypass part begins. Using stabilisers to stop the area surrounding the first blocked artery from moving too much, he sutures the LIMA section of the Y conduit over the blockage. Blood flow is restored to the artery. The next step is difficult because the other two blockages are in the back of the heart. But Dr Varma solves this by flipping the heart over, still beating, to work on the blockages. One blockage is halfway down the heart, while the other is at the bottom.

A consultant cardiothoracic surgeon at an upcoming hospital in Sharjah, who is observing the procedure, says this is what makes the LIMA-RIMA Y conduit unusual. "Previous limitation was length when surgeons tried using the RIMA [independently]. It couldn't always go where a blockage is," he says. With the Y conduit, the RIMA section can now go down the entire heart. Dr Varma stitches the middle part of the RIMA conduit to the second blockage, before moving to the last blockage. 

The final blockage poses the biggest challenge. Because the plaque is one and a half inches long, Dr Varma performs a patch job of sorts. He cuts the coronary artery along the blockage, lays the tail end of the RIMA conduit on top of the artery and sews the two together. It is a painstaking and demanding job, but by 3:45pm all the stitches are in place. It does not end there.

The crucial moment comes five hours after the procedure, when the surgical team removes the breathing tube from the patient, who is now in the Surgical Intensive Care Unit. Initially drowsy, he soon wakes up with Dr Varma and Specialist Anaesthesiologist Dr N. Nallasivam bellowing questions at him. "Good," the patient answers, nodding. The word sums up everything. Reduced risk - The Total Arterial Revascularisation Bypass Surgery on Beating Heart with a Y conduit made from arteries from the chest and forearm is slowly gaining popularity.

Studies suggest that the procedure reduces the mortality or morbidity rate associated with conventional coronary artery bypass.  A retrospective study done by Japanese surgeons and published in the Annals of Thoracic Surgery in 2005 found that the arterial grafting technique was "safe and effective".  It studied 107 patients who underwent coronary bypass surgery and arterial composite grafting on a beating heart from 2001 to 2004, finding that the survival rate was 100 per cent. 

A study by Prift et al, published in the 2003 Journal of Cardiac Surgery found that all 67 patients who underwent the procedure on beating heart (off-pump) or using the heart-lung machine (on-pump) from 1998 to 2001 survived. However, the 20 who underwent the procedure off pump were extubated earlier, left the hospital sooner and showed better coronary artery flow than their on-pump counterparts. 

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