Individual semi-structured interviews were conducted with 27 adult survivors of childhood liver transplants. Each interview was conducted at a place of the participant's choice, with the majority of interviews undertaken at participants' homes. These followed a topic guide created from the clinical and social science literature, plus the experience of one of the research team of nursing children post liver transplant during the 1980s. In addition, individual semi-structured interviews were conducted with eight clinicians involved in the childhood liver transplant programme, which gave context to the transplant recipients' data. Interviews lasted 82 minutes on average (range 20-163 minutes). All were audio-recorded with the participant's permission, transcribed verbatim, anonymised, and imported into NVivo for data analysis. Alongside the profound social and economic changes arising from general population ageing, the past half century has seen the emergence of ‘new’ ageing populations. These populations have arisen through rapid medical progress in tandem with changes in social attitudes to issues surrounding disability and chronic illness.This has led to increasing numbers of people with rare and/or complex disease or disability living considerably longer lives than was historically possible. Many are pioneers; facing issues as they age that have never before been encountered, either by themselves or by professionals leading their treatment and care. One such new ageing population is the first cohort of pediatric liver transplant recipients in the world. Childhood liver transplantation began in the early-mid 1980s in Britain and North America.Thirty years later, many of the British pioneers, still receiving specialist care, are living adult lives. While clinical outcomes are documented, social and ontological issues for these adults, who have lived their whole lives within the context of their body as a project, have never been studied. Through in-depth interviews with transplant recipients and clinicians, we aim to explore both the health and social implications of living with transplanted livers from infancy and wider existential questions surrounding such transforming ‘experimental’ surgery.

We sampled the first ten years of the paediatric liver transplant programme (1984-1994) at Addenbrooke’s hospital, Cambridge, where the programme began in the UK, and at King’s College Hospital, London, which had strong ties to Addenbrooke’s and also began liver transplant surgery during this time. We included those who had had a liver-only transplant at age 13 years or younger, as we were interested to talk to adults who had lived the majority of their life as a transplant pioneer and who had not reached adolescence at the time of their surgery. Letters of invitation and study information were sent by the two hospitals to eligible patients, who were asked to contact the study team if interested. All participants were assured anonymity and confidentiality, and that the research team did not know who the letters had been sent to until an individual chose to reply to the invitation. Early hospital data for the cohort is patchy, as many pioneer recipients have been lost to follow-up, although from discussion with clinicians we believe we interviewed around half of the 1984-1994 surviving UK cohort; around 60 were known to fit our criteria at the time of recruitment.