Development of a multivariable prediction model for prolonged air leak after lung resection.

OBJECTIVES: Prolonged air leak (PAL) is a common complication of lung resection. Research on predictors of PAL using a digital drainage system (DDS) remains insufficient. In this study, we investigated the predictive factors of PAL to establish a novel early postoperative prediction model for PAL. METHODS: A retrospective cohort study and validation study were conducted. We examined patients who underwent lung resection with DDS at our institute. The relationship between the clinical factors and measurements of the DDS, including the difference between the set and measured intrapleural pressure (named: additional negative pressure [ANP]) at postoperative hour (POH) 3, with PAL was analyzed. RESULTS: A total of 494 patients were enrolled, 29 of whom had PAL. Percent forced expiratory volume in 1 s <60%, ANP <1 cmH2O, air leak flow >20 mL/min and pleural adhesion findings at surgery were independent predictors of PAL according to a multivariable analysis. The PAL rate was clearly stratified according to our novel risk scoring system, which simply notes the presence of the above four factors, that is, the rate increases when the score increases. The area under the curve (AUC) of the receiver operating characteristic (ROC) analysis for this scoring system was 0.818. Analysis of the validation cohort (n = 133) revealed that this scoring system showed a sufficient ability to predict PAL. CONCLUSIONS: ANP at POH 3 is an independent predictor of PAL. Thus, the risk-scoring system proposed in this study is useful for predicting PAL in the early postoperative period.

Outcomes and prognostic factors of repeat pulmonary metastasectomy.

OBJECTIVES: Information on prognostic factors after repeat pulmonary metastasectomy (PM) is limited, and outcomes after a third PM are not well documented. METHODS: A single-institute retrospective study was conducted. Between 2000 and 2020, 68 patients underwent repeat PM for pulmonary metastases from various cancers. Outcomes and prognostic factors for the second PM and outcomes after the third PM were analysed. RESULTS: This study included 39 men and 29 women. The mean age at second PM was 53.2 years old. The primary tumours were soft tissue sarcoma in 24 patients, colorectal cancer in 19 and osteosarcoma in 10. The interval between the first PM procedure and detection of pulmonary metastasis after the first PM (months) was ≤12 in 37 patients and >12 in 31 patients. At the second PM, 20 patients underwent lobectomy or bilobectomy, and 48 underwent sublobar resection. Complete resection was achieved in 60 patients, and 52 patients experienced recurrence after the second PM. The 5-year relapse-free survival and overall survival rates after the second PM were 27% and 48%, respectively. Multivariable analysis revealed that the interval between the first PM and the subsequent detection of pulmonary metastasis (≤12 months) was a poor prognostic factor for both relapse-free survival and overall survival after the second PM. Seventeen patients underwent a third PM, 3 of whom achieved a 3-year disease-free survival. CONCLUSIONS: Patients with a period of >12 months between the first PM and the subsequent detection of pulmonary metastases showed favourable outcomes and are thus considered good candidates for second PM. A third PM may be beneficial for selected patients.

Small-sized type A thymoma with pulmonary metastasis: a case report.

BACKGROUND: Type A thymomas comprise a homogenous population of neoplastic epithelial cells that are characterized by a spindle/oval shape without nuclear atypia. They may be accompanied by few non-neoplastic lymphocytes. Most type A thymomas are detected in the earlier Masaoka stages. Compared to other thymoma subtypes, they rarely metastasize or recur. There have been some reports of patients with type A thymomas with pulmonary metastasis; however, these thymomas were 20 mm or more in size. Herein, we report the case of a patient who underwent surgical resection for a small-sized type A thymoma (12 mm) with pulmonary metastasis. CASE PRESENTATION: A 62-year-old patient presented with an abnormal shadow in the left lung on plain chest radiography during a medical checkup. Chest computed tomography revealed a 12-mm tumor in the anterior mediastinum and a 13-mm nodule in the left lower lobe. 18F-fluorodeoxyglucose positron emission tomography/computed tomography revealed uptake in the anterior mediastinal tumor, but did not show a significant uptake in the pulmonary nodule. The patient underwent surgical resection on two separate occasions, and was diagnosed with an atypical type A thymoma and pulmonary metastasis. The TNM classification was p-T1aN0M1b stage IVb, and it was stage IVb according to the Masaoka staging system. No recurrence was observed during the follow-up. CONCLUSIONS: We report a case of the smallest type A thymoma with pulmonary metastasis. Pulmonary metastasis secondary to a type A thymoma should be considered even if the thymoma is small in size (< 20 mm).