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Photo above: Mr Craig Andrew McEvoy (left), who had a minimally invasive procedure on his heart valve, has a smaller scar compared with Mr Choo Kok Weng (right), who had conventional surgery.
SINGAPORE - It used to be that patients who had heart valves repaired or replaced would come out of surgery with a scar that stretched the entire length of the sternum or breastbone.
It would start right below the neck's hollow, run down the centre of the chest and end above the abdomen.
Patients would carry a 15 to 20cm long scar for the rest of their lives.
This traditional method of heart surgery, called full median sternotomy, separates the sternum to expose the fist-sized heart muscle for surgeons to work on.
While this is still the standard approach in cardiac surgery, less invasive techniques have been used in recent years by a handful of doctors here, with one even developing his own method.
There is no formal consensus on what constitutes minimally invasive cardiothoracic surgery. It is understood that the term refers to operations performed through incisions other than the traditional full median sternotomy.
They usually involve smaller incisions, which reduce body trauma, hence potentially reducing pain, scarring and recovery time.
Minimally invasive cardiothoracic surgery was first introduced during the 1990s, driven by major improvements in technology.
Associate Professor Theodoros Kofidis, head of the division of adult cardiac surgery at the department of cardiac, thoracic and vascular surgery at National University Heart Centre, Singapore (NUHCS), said the move was also a response to changing patient expectations.
He said patients used to be grateful for coming out of open heart surgery alive, but soon also expected to have the least possible complications.
Improved cosmetic results were later added to their wishlist, which prompted surgeons to adapt to those needs, he said.
He set up the minimally invasive cardiac surgery programme in NUHCS three years ago. Since then, he has been using the minimally invasive approach for four in every 10 patients who require surgery on a single heart valve. He has also developed his own method.
The National Heart Centre Singapore (NHCS) has been using the minimally invasive approach in heart valve surgery since 2007.
Smaller incisions
Minimally invasive heart surgery can be used to fix faulty heart valves, a hole in the heart, irregular heartbeats and for coronary artery bypass graft surgery to improve blood supply to the heart. However, this technique is not used when many defects occur at the same time.
During heart valve surgery, sternotomy can be done with a smaller incision which cuts through half the sternum, said Dr Lim Yeong Phang, a cardiovascular and thoracic surgeon at Gleneagles Hospital and Mount Elizabeth Novena Hospital.
The scar would be 6 to 8cm long.
The operation, known as upper sternotomy, still involves cutting the breastbone and joining it back with steel wires.
Dr Lim said any bone fracture requires six weeks to heal properly, during which patients should not drive or lift anything heavier than a newborn baby.
Thus, another approach which does not involve bones but cuts through just soft tissue and muscles would speed up the healing process.
Prof Kofidis said a patient may be in hospital for 10 days after undergoing full median sternotomy and eight or nine days after upper sternotomy.
A procedure called right minithoracotomy could further reduce the stay to about five days, he said.
In this procedure, the surgeon makes a 4 to 10cm incision between the ribs on the right chest and another three to five incisions, or portholes, near the area for the passage of surgical instruments. Each porthole is between 5 and 10mm. No bone is involved.
The operation also requires a 4cm incision in the groin, through which doctors insert tubes, called cannulas, to be connected to a heart-lung machine that takes over the functions of the patient's heart and lungs during the operation.
This approach has been used on patients at NUHCS since 2009 and with robot-guided instruments since 2010.
Eleven patients of NHCS have also had robot-assisted mitral valve repair through minithoracotomy. The mitral valve is one of four heart valves which should open one way only to allow blood through.
Businessman Craig Andrew McEvoy, 49, was lucky to benefit from less invasive surgery. The Australian is the only patient at NUHCS who has undergone Prof Kofidis' modified minithoracotomy. His leaky mitral valve was repaired through a single 6cm incision in his right chest.
For three months last year, he was hospitalised when a streptococcus infection affected his brain and heart. He also had other problems such as water collecting in his abdomen, inflammation of the pancreas and a fatty liver.
Mr McEvoy, who is moving to Bangkok after living here for 20 years, said he used to drink and smoke heavily while entertaining customers at his pub.
Prof Kofidis said the bacteria had perforated Mr McEvoy's mitral valve so it could not close tightly and caused blood to flow back wrongly into the heart.
Mr McEvoy and his 48-year-old Thai wife, Mrs Bunsri McEvoy, were sold on the prospect of a faster recovery, as he was in poor health and had lost 20kg during the three months when he was hospitalised.
He was admitted to NUH for 17 days after the heart valve surgery - longer than if he had been a healthier patient.
The businessman, who has cut down on his smoking, recalled: "With me pushing 50 years of age, I was not too bothered by the size of the scar. But as I love going to the beach, the small scar was definitely an added bonus for me."
Not for everyone
Despite the appeal of smaller scars, not everyone is suitable for less invasive techniques.
Dr Tan Teing Ee, a senior consultant at the department of cardiothoracic surgery in NHCS, said patients who are unstable, have other serious medical conditions or lung disease, have a small rib cage or require other cardiac procedures, such as a bypass, at the same time are not suitable.
One such patient is church worker Choo Kok Weng, 50, who was diagnosed with coronary artery disease and mitral regurgitation last December.
He had an operation on Jan 25 to repair his mitral valve, which did not close as tightly as it should, and also had a coronary bypass to replace a blocked heart vessel with one taken from the chest wall.
He was hospitalised for five days at Gleneagles Hospital and now has an 18cm scar, but he is not too bothered. Instead, he is thankful his ailments were detected before a heart attack endangered his life.
Sometimes, surgeons have to revert to the traditional approach in the event of complications during surgery.
In one study published in the European Journal Of Cardio-Thoracic Surgery in 2008, four out of 1,339 patients who went in for minimally invasive mitral valve repair for mitral regurgitation had to have the surgery converted to sternotomy because of problems such as excessive bleeding and tears in the aorta, the main artery arising from the heart.
The authors found that 83 per cent of patients reached the five-year survival rate, while 96 per cent did not require another mitral valve-related operation in that same period.
A drawback of this study was that there was no control group to compare against as the Leipzig Heart Center of the University of Leipzig in Germany had made minimally invasive mitral valve surgery its procedure of choice since the late 1990s.
In other studies, 92 per cent of patients who underwent sternotomy survived for at least 10 years, while 93 per cent of patients did not require another operation in the five years afterwards.
Another study published in The Journal Of Thoracic And Cardiovascular Surgery last April compared early outcomes from 138 patients who had minimally invasive aortic valve surgery by minithoracotomy and matched them to a control group of 138 with conventional full sternotomy.
Overall, 0.7 per cent of patients died in hospital, with no difference between the two groups. The incidences of stroke, renal failure and wound infection were similar.
Those who were operated on using the less invasive approach also had a lower incidence of post-operative irregular heartbeat and blood transfusion and shorter ventilation time and hospital stay.
Challenges and complications
Challenges and complications
At least three cardiothoracic surgeons said they did not think minimally invasive approaches would become the standard of care for heart valve surgery yet.
They said the promising results from overseas studies are difficult to replicate here as surgeons do not have a large pool of heart valve patients to hone their expertise in this technique.
Dr Lim has performed thoracotomy only once, in 2009, on a patient whose "unique anatomy" made him unsuitable for sternotomy.
His heart was displaced to the right side of his chest as his right lung had been removed earlier, so the right thoracotomy was optimal.
Dr Sriram Shankar, a consultant cardiothoracic and vascular surgeon at Gleneagles Medical Centre, said he offers thoracotomy only to patients who have had sternotomy previously.
Scar tissue forming on organs after the first operation would make it complicated to do another operation at the same spot in the sternum, he said.
He said complications, such as internal bleeding, can be more easily tackled if a patient has had sternotomy, as doctors can simply remove the steel wires on the sternum to access the heart in intensive care, which takes five minutes.
On the other hand, a patient who had thoracotomy would have to be wheeled back into the operating theatre to have his chest cracked open using sternotomy.
joanchew@sph.com.sg
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