How can the rate of nontherapeutic thymectomy be reduced?

The aim of this study was to determine the prevalence of nontherapeutic thymectomy and define a clinical standard to reduce it.

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.

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.

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.