How can the rate of nontherapeutic thymectomy be reduced?

OBJECTIVES: The aim of this study was to determine the prevalence of nontherapeutic thymectomy and define a clinical standard to reduce it. METHODS: From 2016 to 2020, consecutive patients who underwent thymectomy were retrospectively reviewed. Univariable and multivariable analyses were used to identify the correlation factors of nontherapeutic thymectomy. A receiver operating characteristic curve was analysed to assess the cut-off threshold of factors correlated with nontherapeutic thymectomy. RESULTS: A total of 1039 patients were included in this study. Overall, 78.4% (n = 814) of thymectomies were therapeutic and 21.6% (n = 225) were nontherapeutic. Thymoma (57.9%, n = 602) was the most common diagnosis in therapeutic thymectomy. Among those of nontherapeutic thymectomy, thymic cysts (11.9%, n = 124) were the most common lesion. Compared with therapeutic thymectomy, patients with nontherapeutic thymectomy were more likely to be younger (median age 50.1 vs 55.6 years, P < 0.001) with a smaller precontrast and postcontrast computed tomography (CT) value (P < 0.001, P < 0.001), as well as ΔCT value [10.7 vs 23.5 Hounsfield units (HU), P < 0.001]. Multivariable analysis indicated that only age and ΔCT value were significantly different between therapeutic and nontherapeutic thymectomy groups. Receiver operating characteristic curve analysis showed that cut-off values of age and ΔCT value were 44 years and 6 HU, respectively. Patients with age ≤44 years and a ΔCT value ≤6 HU had a 95% probability of nontherapeutic thymectomy. CONCLUSIONS: Surgeons should be cautious to perform thymectomy for patients with age ≤44 years and ΔCT value ≤6 HU. This simple clinical standard is helpful to reduce the rate of nontherapeutic thymectomy.