Maixner was appointed to the position of Director of the Royal Children's Hospital Neurosurgery Department in 2001,[7] becoming one of the youngest neurosurgery department heads in Australia and the first female head of neurosurgery at the Children's Hospital.[6]
From October 2001 until July 2004 Maixner served on the Victorian Surgical Consultative Council,[8] a special purpose council established in 2001 by the then-Minister of Health, John Thwaites, which reports to the Minister for Health and analyses, studies and reports on potentially preventable surgical deaths in Victoria, with the aim of improving the safety and quality of surgery in Victoria.[9]
In 2006, Maixner was credited with performing "ground-breaking" surgery when she operated on a three-year-old girl to successfully stop seizures caused by a rare genetic condition. Maixner told media at the time that the surgery was of the same complexity as open-heart surgery.[10]
On 16 May 2007, Maixner worked with Rob Briggs, the medical director at the Royal Victorian Eye and Ear Hospital's Cochlear Implant Clinic and using "pioneering technology" they performed the first auditory brainstem implant on a child in Australasia. At the time, the surgery was hailed as an advancement that "could pave the way for revolutionary advances in medicine".[11]
Between 30 and 31 August 2009, Maixner presented at the XIV World Congress of Neurological Surgery in Boston, Massachusetts as a faculty member of the "Pediatric Neurosurgery: An Overview with Sub-specialty Applications" program and as a panelist on the "Chiari Type I Malformation in Children" discussion panel.[12]
On 16 and 17 November 2009, Maixner led a team of 16 neurosurgeons, plastic surgeons, and other specialist medical staff at the Royal Children's Hospital in the 32-hour "groundbreaking surgery" to successfully separate three-year-old Bangladeshi conjoined twins, Trishna and Krishna.[13] The twins were found in 2007 by two Australian Aid volunteers in Mother Teresa's orphanage in Dhaka and brought to Australia by Moira Kelly and the Children First Foundation for life saving medical treatment, which involved a series of operations in January, February, March, May, October, and November 2008 and January and August 2009, in preparation for the final separation in November 2009.[14] Maixner had performed four major operations on the twins to separate and close shared blood vessels and insert tissue expanders and prior to the final surgery, she gave the twins a 25 percent chance of surviving the operation, a 25 percent chance of dying and a 50 percent chance of suffering "catastrophic" brain damage, but without surgical intervention, both children would die.[15][16] On 19 November 2009, Maixner told the press that Trishna had woken from the medically induced coma.[17] Krishna began to wake up on 20 November 2009.[18] On 21 December 2009, five weeks after the surgery to separate the twins, they were released from the hospital.[19]
On 26 November 2009, Maixner and other members of the medical and surgical team who cared for Trishna and Krishna were honoured with a civic reception hosted at Government House in Melbourne by Governor of Victoria, David de Kretser and Premier John Brumby.[20]
Maixner and fellow Royal Children's Hospital neurosurgeon Alison Wray sat for Australian artist Raelene Sharp in December 2009. Sharp's portrait of the surgeons was submitted to the Australian portrait competition, the Archibald Prize. The competition was judged in March 2010 and carries a A$50,000 prize.[21] Maixner was also featured in a photo shoot by The Australian Women's Weekly in December 2009.[22]
In 2023, the Royal Children's Hospital awarded Maixner the Elizabeth Turner medal for the excellence she demonstrated in clinical care.[23] As of 2023, Maixner continued to practice neurosurgery, and has expressed that her greatest achievement at the Royal Children's Hospital is helping to grow a cohesive unit, based on respect, that nurtures people to become the best that they can be.[24][25]
Maixner left the Royal Children's Hospital in 2025.
