Vettivetpillai Ketharanathan or ‘Nathan’ was a senior research associate at the vascular surgery unit at the Royal Melbourne Hospital, Victoria, Australia. He was born in Jaffna, Sri Lanka, on 25 November 1935 to Appiah Ketharanathan and Rukmani Nama (Sivayam) Ketharanathan, who were both teachers. He attended Jaffna Central College, but from the age of 14, when his father died, he had to shoulder the burden of family responsibilities. He studied medicine in Colombo, qualifying in 1960. After house jobs in Colombo and four years as a registrar at the General Hospital, Malacca, he went to Melbourne in 1966, as a registrar on the cardiothoracic unit at the Royal Melbourne Hospital, where he came under the wing of Ian McConchie. He became an Australian citizen, and was encouraged by McConchie to go to London, where he completed registrar posts in Hackney and the Brompton Hospital. He returned to Melbourne, where he began to carry out research into improved biomaterials for replacing cardiac valves and blood vessels, research he continued whilst he was working as a consultant thoracic surgeon at Ballarat. This work took him later to Portland, Oregon, as an international fellow in cardiopulmonary surgery. A number of new materials were patented by him and in 1990 he set up two companies, BioNova International and Kryocor Pty, to exploit them, whilst he was appointed senior research associate at the Royal Melbourne Hospital. An indefatigable investigator, he was an inspiration to many young surgeons. Among his many interests were cooking, and he was a regular client at the Queen Victoria market, seeking the freshest produce, rewarding his friends with examples of Sri Lankan fare. He died on 3 March 2005, leaving his wife Judith, and four children, of whom his eldest daughter, Selva, is an infectious diseases specialist at Sir Charles Gardiner Hospital in Perth. His second daughter, Naomi, is about to qualify at Amsterdam.