Safety and efficacy of connecting the residual ear to the cartilage scaffold in the first-stage versus second-stage surgery: a protocol of a randomised controlled trial in non-expanded auricular reconstruction for concha-type microtia

Introduction Concha-type microtia, classified as a milder form of microtia under Nagata’s classification, is characterised by the presence of more normal ear subunits compared with other types. The non-expanded auricular reconstruction using autologous rib cartilage is a standard procedure treating conchal microtia, and this operation typically comprises two stages. To maximise the utilisation of native auricular cartilage, the lower half of a patient’s ear is preserved as residual ear, which should be connected to the rib cartilage scaffold in this operation. However, it remains unclear whether this connection should be performed in the first-stage or second-stage surgery. Current literature lacks sufficient evidence to determine the safer and more effective approach. Thus, we plan to conduct this randomised controlled trial to formally compare the safety and efficacy of first-stage versus second-stage connection, hypothesising that second-stage connection may be a better choice since it may reduce skin cutting, operative risk and improve recovery. Methods and analysis This is a single-centre, randomised controlled trial comparing two surgical treatments. Based on sample size calculations, a total of 78 eligible patients will be randomised with a 1:1 allocation. The control group will be treated with connecting the residual ear with the framework in stage 1, while the experimental group will be treated with connecting the residual ear with the framework in stage 2. The safety of the surgery will be evaluated based on the grade-A healing rate and the incidence of complications (infection, haematoma, flap or skin necrosis and cartilage scaffold exposure). Efficacy of the surgery will be assessed using the Patient and Observer Scar Assessment Scale (POSAS) and Glasgow Benefit Inventory (GBI) scores. Patients will be scheduled for follow-up 3–6 months after each surgery. Descriptive analyses will be performed to summarise baseline demographics. The incidence of grade-A healing and complications will be analysed using the χ 2 test. GBI and POSAS scores of the two groups will be analysed using independent-samples t test. A p value