Published papers

Background: Unilateral diaphragmatic paralysis is a condition in which the unilateral diaphragm is paralyzed and elevated. Orthopnea due to lung compression by an elevated diaphragm in the supine position is common in patients with unilateral diaphragmatic paralysis. Although its symptom is posture-dependent, the effect of posture on lung function in unilateral diaphragmatic paralysis has not been studied. Computed tomography (CT) can be used to assess lung volume. However, conventional CT cannot be performed in the upright position. A pulmonary function test can be performed in both upright and supine positions. However, it cannot evaluate the function of each lung separately. Case presentation: We report a case of a 79-year-old man with unilateral diaphragmatic paralysis. He presented with difficulty in inspiration, specifically in the supine position, and underwent both conventional supine CT and newly developed upright CT to assess the effect of posture on the function of each lung. The difference between expiratory and inspiratory lung volumes on CT in the supine position was less than that in the upright position by 46% and 4% on affected and healthy sides, respectively. We previously reported that the difference between expiratory and inspiratory lung volumes on CT correlated with inspiratory capacity on the pulmonary function test. A 46% decline in inspiratory capacity on the affected side in the supine position likely caused orthopnea in this patient. Conclusions: Supine/upright CT is helpful to assess the influence of posture on unilateral lung function in patients with unilateral diaphragmatic paralysis.

Purpose: Salvage surgery for primary lung cancer is expected to become increasingly common. This study aimed to clarify the survival impact of pathologic characteristics after salvage surgery. Methods: Consecutive patients who underwent salvage surgery following definitive chemoradiotherapy or systemic therapy for initially unresectable lung cancer from 2010 to 2020 were enrolled in this study. The tumor slides were reviewed to determine the size of the tumor bed and the proportions of viable tumor, necrosis, and stroma. Results: A total of 23 patients were evaluated, and 18 had clinical stage IIIB–IV disease. Six received chemoradiotherapy and 17 received systemic therapy alone. A major pathologic response (MPR, ≤ 10% of viable tumor) was observed in 6 patients, and 4 patients achieved a pathological complete response. The 3-year overall and recurrence-free survival rates (OS and RFS) were 78.6% and 59.2%, respectively. There was no significant difference in OS between patients with and without MPR, and even non-MPR patients achieved a favorable 3-year OS of 70.2%. Meanwhile, patients with high (≥ 30%) stroma showed significantly better OS than those with low (< 30%) stroma (3-year OS: 100% vs. 23.3%, p < 0.001). Conclusions: This study showed that the proportion of stroma can be useful for predicting long-term survival after salvage surgery. Further large-scale studies are warranted to confirm the current findings.

OBJECTIVES. Cases of severe pectus excavatum presenting with worsening cardiopulmonary symptoms in the upright position have been reported. However, the underlying mechanism remains unclear. We evaluated posture-related morphological changes of the thorax in patients with pectus excavatum. METHODS. Chest morphology was evaluated preoperatively using upright and supine computed tomography in 21 patients with pectus excavatum and 35 healthy volunteers. The minimum anterior–posterior thoracic diameter, depression depth, and Haller index on horizontal sections, as well as the T6-12 plumb line distance on sagittal sections, were compared between the 2 positions. RESULTS. In patients with pectus excavatum (median age, 22 years; 18 males and 3 females), the minimum anterior–posterior diameter was smaller (4.5 vs 5.1 cm, P < 0.001) and the Haller index was greater (10.1 vs 6.4, P < 0.001) in the upright position than in the supine position. The T6-T12 plumb line distance was longer in the upright position (2.4 vs 0.8 cm, P < 0.001), while the depression depth showed no significant difference. Healthy volunteers exhibited similar changes. The degree of spinal curvature increased in the upright position due to the anterior shift of the lower thoracic vertebrae, resulting in a shorter anterior–posterior diameter, irrespective of chest wall deformity. One patient with dyspnoea only in the upright position exhibited compression of the right inferior pulmonary vein only on upright computed tomography. CONCLUSIONS. The minimum anterior–posterior diameter is shorter in the upright position. This may explain the worsening of cardiopulmonary symptoms in patients with severe pectus excavatum when in an upright position.