The paediatrician said his team was well prepared for the surgery and there weren't any complications or major bleeding during the procedure.
Conjoined Bhutanese sisters were separated in a six-hour operation at an Australian hospital on Friday (Nov 9) and the lead surgeon said he was quietly confident the infants would recover successfully.
As the public eagerly waits for good news, the Royal Children's Hospital is not expected to release any information about the progress of the operation until 4pm on Friday, with Dr Crameri to give his first update on the girls early on Saturday morning.
"The positioning makes it hard for surgeons Joe Crameri, Tom Clarnette and Michael Nightingale, who are charged with separating the gilrs' shared liver, crossed over bowels and any other internal organs", it states.
Once the girls' internal organs were separated, the incisions will be closed over using skin, muscle and fat.
He said the next 24 to 48 hours would be critical to their recovery, but was optimistic about the outcome.
Conjoined twins Nima and Dawa are seen at Miracle sMiles Retreat in East Kilmore, Victoria.
As well as the issues with mobility and comfort, Lodge said the twins had recently been losing weight, which had been a concern to doctors who are now observing them closely.
They headed into the theatre at 8am, and doctors planned to administer anaesthesia around 8.45am.
Elizabeth Lodge, chief executive of a charity that's assisting, says the girls' mother, Bhumchu Zangmo, was both nervous and happy about the operation to separate the twins.
She will spend Friday praying and meditating.
Fortunately it was found that the babies" bowels were a "bit intertwined" but otherwise not connected "in any major way'.
"She still has this extraordinary calmness about her, which is just unbelievable".
Sherub first met the girls when they were only a day old and played a major role in getting the twins to Australia, having already spent time in the country as the victor of a medical scholarship.
The girls and their mother, Bhumchu Zangmo, were brought to Australia last month by the Children's First Foundation charity, which said the Victorian state government had covered the cost of the surgery while it looked after transport and accommodation.
The girls, pictured with their mother before the surgery, are now breathing on their own.