In 1997, he was invited to join the senior staff in the Plastic Surgery Unit at Middlemore Hospital, where he focused on cleft lip and palate surgery, and chest wall reconstruction.Tristan has received numerous respected awards and scholarships and has more than 40 peer-reviewed journal articles and book chapters to his credit. Despite the breadth and depth of his training and experience, a key passion remains facial restoration following skin cancer, injury or ageing. Travelling annually to the Philippines, he treats underprivileged children with cleft lip and palate conditions pro bono for Operation Restore Hope NZ. He also offers his time and expertise for free at the Auckland Regional Charitable Hospital.
Tristan particularly specialises in facial restoration after trauma or cancer restoration, body contouring, complex reconstructions and paediatric plastic surgery. He also offers a comprehensive range of breast and hand surgeries. As an aesthetic surgeon, he is best known for his work on restoring the ageing face, offering a range of non-surgical and surgical approaches to rejuvenation of the eyelids, the face, the mid-face, the neck, mouth and chin and the brow.