(Oct 11) OPEN-HEART surgery is delicate enough, but the KK Women's and Children's Hospital (KKH) has done two this year on a pair of premature babies with tickers the size of macadamia nuts.

The 1kg infants, born two months premature to different families, had defects that needed corrective surgery - and soon - or they would have died.

The operations in February and July have made KKH South-east Asia's first hospital to do micro-surgery on hearts just 2cm across. The first such open heart micro-surgery was done on a two-day-old boy in 1992 in the US.

Associate Professor V. Samuel Rajadural, who heads the hospital's Department of Neonatology, said untreated premature babies with heart defects usually die within six months.

Aside from having to do the operations using microscopes, surgeons had to minimise blood loss. In these tiny patients, losing even 10ml of blood - about two teaspoons' worth - can be fatal.

One of the babies was Muhammad Izz Miqdam Zainol (above right, held by Madam Nor-Asikeen Mohd Taib), one of a pair of twins who was born with a narrowed aorta, the main blood vessel that channels oxygen-rich blood to the rest of the body.

That made the flow of blood to his lower body very poor, and nurses found Miqdam's legs turning cold.

He was operated on at age 15 days in February by a team led by KKH's Cardiothoracic Surgery Service head, Dr Shankar Sriram.

Associate Professor Wong Keng Yean, who heads KKH's Paediatric Cardiology Service, explained that the operation involved opening up the heart, clamping the aorta briefly, removing the narrowed area and joining the fresh ends to each other.

Repairing the narrowed bit took 16 minutes 49 seconds, with the whole operation taking just over an hour.

Anaesthetist Shani Tan said speed was necessary to cut the risk of blood loss. She explained that 5ml or a teaspoon of blood in a premature baby weighing 1kg was equivalent to a pint of blood in an adult.

The operation Miqdam had was not his last. Like 15 per cent of babies who suffer re-narrowing after corrective surgery, he had a recurrence. This is caused by scars from the previous operation.

His mother, Madam Nor-Asikeen Mohd Taib, 32, said she became concerned when he did not feed well.

Tests showed the blood vessel had narrowed again, so Miqdam underwent balloon angioplasty at age six months to keep it open.

The other premature baby was Gladys Lin Weiqi (above, held by mother Madam Ng Yek Hui), born at 31 weeks by emergency caesarean section because her mother, Madam Ng Yek Hui, 25, had high blood pressure.

In Gladys' case, oxygen-rich blood, instead of circulating to nourish the muscles and internal organs, was being sent to the lungs to be oxygenated, while oxygen-poor blood made its rounds.

The timing of her operation was critical: it had to be done in her first two weeks, or one of her heart valves would not function. However, if done too soon, her brain could bleed.

She was nine days old when she had a four-hour operation.

She is now a month old, and Miqdam, eight months old. Both babies will require regular follow-ups.

juditht@sph.com.sg