IN CASE YOU MISSED IT

From six cuts to one

One doctor here has entered the race to make surgery on faulty heart valves less invasive - using modified surgical tools to reduce the number of cuts made in the body from five or six to one.

Associate Professor Theodoros Kofidis, senior consultant and head of adult cardiac surgery at National University Heart Centre, Singapore (NUHCS) successfully repaired 49-year-old businessman Craig Andrew McEvoy's valve through a single cut on the chest last December.

Prof Kofidis, 43, calls the procedure the single incision minimally invasive cardiac surgery.

Most patients with mitral and tricuspid heart valve disease, estimated to exceed 200 here each year, may benefit from the new operation, he said.

The mitral valve separates the two left chambers of the heart, while the tricuspid valve separates the two right chambers. They can become torn or leaky because of ageing, heart failure and congenital defects and need to be surgically repaired.

His main innovations include modifying the atrial retractor, a tool which holds the incision in the heart open to expose the valves inside; and the aortic cross-clamp, which is used to stop blood flowing through the aorta during surgery.

The atrial retractor, which occupies a porthole in the chest wall, is a bulky instrument with three arms which takes up standing space in the operating theatre.

Prof Kofidis' replacement is a malleable steel plate that is inserted through the single incision. It is flexed to hold the incision in the heart open and clamped outside the body to hold it in place. No porthole is required. After the operation, it is simply removed. A paper on this was published in The Annals Of Thoracic Surgery in 2011.

The aortic cross-clamp occupies another porthole in the chest wall. Prof Kofidis used one invented by an Italian surgeon, which has handles that can be detached and removed while it is in use.

This means that it can be passed through the single 6cm incision between the ribs and will not require a separate porthole.

Another innovation involves the incisions that are made in the thigh. They allow blood to be pumped out and in through the femoral vein and artery respectively and passed through a heart-lung machine, which takes over the function of the patient's heart and lungs during the operation.

In the conventional minithoracotomy, the blood vessels are accessed through a 4cm skin incision. After the surgery, the cuts in the vessels are stitched closed before the skin incision is also closed.

In Prof Kofidis' procedure, the tubes to connect these two blood vessels to the heart-lung machine are passed through holes smaller than 5mm in the skin, which do not require stitching.

Prof Kofidis then uses a special device that delivers sutures through the skin to close the vessels, without the need for any skin incisions.

This device is already used in less major heart procedures such as the insertion of a stent to keep a partially blocked blood vessel open, he said.

Besides the improved cosmetic outcome, the new technique may also help cut complications from surgery, though this will have to be shown in clinical studies.

Patients who cannot have the procedure are those who are severely obese, have aortic valve leakage or have less conventional heart anatomy.

A thick layer of fat in the body can obstruct a surgeon's view during minimally invasive, single incision surgery, Prof Kofidis said.

A subsidised patient at NUHCS pays between $3,100 and $13,200 for the new procedure. This is $2,000 more than what he would pay for full median sternotomy, which costs between $1,100 and $11,200, depending on the level of subsidies.

This story first appeared in The Straits Times on March 7, 2013

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