Representational image.Creative Commons

A baby boy has been successfully separated from his parasitic twin in a 15-hour-long operation. The fully formed baby boy, Haneen, was cut away from his conjoined twin, which was a girl, in a gruelling procedure undertaken by a team of doctors.

The twin-sister, named Farah, unfortunately, couldn't survive as her own lungs and heart were yet to develop and she also had very little brain tissue, as is the case with most parasitic twins – that basically live off the healthier or host twin's body.

Also read: Baby born with 'parasitic penis'

As explained by Live Science, these parasitic twins occur when identical twins fail to separate and the undeveloped twin's tissues become dependent upon the 'host'.

Even though it is largely unclear why this occurs, restricted blood supply during pregnancy often leads to the death and partial absorption of one of the twins. The condition occurs in around one in a million live births.

As Daily Mail reported, the surgery had started at 8am and did not finish until 11pm that evening. The doctors first separated the twins' intestines and liver, and then their urinary system and pelvis.

Representational image.Creative Commons.

The twins were connected via the abdomen – as is normal in most cases of conjoined twins – and were separated from the hips at the King Abdullah Specialised Children's Hospital in the Saudi capital, Riyadh.

Haneen's recovery is still unclear, primarily because of the rarity of conjoined twins surviving. As the procedure was being carried out, the surgeon Dr Al-Rabiah said: "The surgery is going on as planned successfully, and the Kingdom of Saudi Arabia will record it as the 45th successful twin separation surgery."

The surgery – which was extremely complicated – involved inserting tiny cameras into the babies' separate urethras, which were followed by catheters. The babies' age at the time of the procedure has not been revealed yet.

Representational image.Creative Commons.

A similar case had surfaced the news not so long ago when a little boy was born with a 'parasitic penis' on his back since he had absorbed his twin in the womb and all that was left off the underdeveloped twin was the genitalia attached to the healthy one's back.

Also, back in 2016, a woman named Hemlata Singh, from Jodhpur, India, gave birth to a healthy-baby named Sonni, who had his partially formed parasitic twin attached to his stomach. This put the healthy-born baby's life at risk too.

Also read: Twins with separate birthday, month and year

Fortunately, Sonni was just nine-days-old when he was separated from the parasitic twin, via the liver they shared, before disconnecting the artery carried blood from Sonni's heart to his twin's deformed organ.

Sadly, the twin couldn't make it and died shortly after surgery, with Sonni going home 12 days later.