Background: In lung transplantation (LTx), patients with thoracic muscle sarcopenia may have to require longer to recovery. We measured thoracic muscle volume by using the cross sectional area (CSA) and assessed its effect on early outcomes after LTx.Methods: A retrospective analysis was conducted to evaluate the effect of thoracic sarcopenia in patients undergoing LTx between January 2010 and July 2015. The lowest CSA quartile (Q1) was defined as sarcopenia.Results: In total, 109 patients were enrolled. 50.8±37.2 days, P= ns) tended to be longer in Q1 than Q4, but the difference was not significant. However, the 1-year survival rate was better in Q1 compared with Q4 (66.6% vs. 46.0%, P=0.04).Conclusions: Although patients with thoracic sarcopenia seem to require a longer post-operative recovery time after LTx, this does not compromise their early outcomes. By contrast, patients with larger thoracic muscle volume (Q4) showed poorer survival times.Keywords: Lung transplantation (LTx); sarcopenia; thoracic muscles; cross sectional area (CSA) Computed tomography (CT) (10), magnetic resonance imaging (MRI) (11), bioelectrical impedance (BIA) (12), anthropometry (13), and dual-energy X-ray absorptiometry (DXA) (14) have been used to assess muscle mass, while handheld and computerized dynamometry have been used to measure hand grip and quadriceps strength (3,15). Short Physical Performance Battery and usual gait speed can assess functional status (16-18). The 6-minute walk test is the most commonly used modality to assess functional status but it cannot index isolated muscle function as part of the sarcopenia definition (5).SubmittedSome studies of LTx patients have focused on low muscle mass and the importance of rehabilitation after LTx (3,4), but the clinical effect of sarcopenia on LTx outcome has not been studied until now. In this study, we hypothesized that thoracic skeletal muscle mass measured by analyzing the CSA from a chest CT image could be a predictor of early outcomes and survival after LTx, and can also be used to assess the suitability of lung transplant candidates.
Methods
PatientsThis study was approved by the Severance Hospital Institutional Review Board (4-2016-0129). We retrospectively reviewed the medical records of 111 patients who underwent LTx at our institution between January 2010 and July 2015. Age, sex, underlying diseases, height and weight at the time of the operation, post-operative course and mortality data were collected for all patients; data on thoracic muscle CSA were available in 109 of the patients.
Measurement of thoracic skeletal muscle CSAThe thoracic muscle CSA at the level of the carina was determined based on a study performed by Rozenberg et al. (19). The first single slice identifying at carina level on each patient's chest CT scan was selected. We then outlined the borders of the thoracic skeletal muscle (pectoralis, intercostal and paraspinal muscles) in the CSA, and the area was measured (Figure 1). These steps were completed semiautomatically using Aquarius iNtuition...