Influence of lung resection volume on risk of primary spontaneous pneumothorax recurrence.

BACKGROUND: Thoracoscopic stapled bullectomy is a popular procedure for the treatment of primary spontaneous pneumothorax (PSP) that has a relatively high postoperative recurrence rate. One reason for PSP recurrence is the formation of a new bulla around the staple line. We hypothesized that different resected specimen volumes might cause differences in staple line tension. In this study, we analyzed the relationship between postoperative pneumothorax recurrence and resected lung volume. METHODS: Between April, 2009 and December 2013, 360 cases which underwent video-assisted thoracoscopic surgery (VATS) for PSP were selected. Recurrence after VATS was examined by electronic medical records and telephone survey. Resected volume and vertical area of specimen were calculated with the size of pathologic specimen. RESULTS: A mean follow up period was 44.5±24.4 months and recurrence rate was 11.1% (40/360). Large volume of resected specimen (≥16 cm3) (P=0.027 by the log-rank test) and larger vertical area of resected specimen (≥2.0 cm2) (P=0.003 by the log-rank test) showed significantly high recurrence rate. Cox regression analysis demonstrated that age [hazard ratio (HR), 0.083, P=0.006], vertical section area of resected specimen (HR, 1.239, P=0.020) and volume of resected pathology specimen (HR, 1.039, P=0.009) were independent risk factors of recurrence. CONCLUSIONS: Bulky resection during VATS for PSP increases the risk of recurrence. Large volume and vertical area of resected specimen are associated with greater tension in stapling line. Avoidance of wide resection and the firing of stapler after full collapse of lung are recommended for reducing the pneumothorax recurrence after VATS.

A new protocol for concomitant needle aspiration biopsy and localization of solitary pulmonary nodules.

BACKGROUND: Pulmonary nodules may require thoracoscopic resection in cases where percutaneous needle aspiration (PCNA) is non-diagnostic or not technically feasible. We developed a new protocol to localize pulmonary nodules concomitantly with PCNA. We retrospectively reviewed the use of concomitant PCNA and preoperative localization under computed tomography (CT) guidance. METHODS: From Jan 2006 to Dec 2013, we performed PCNA and localization concomitantly on 34 pulmonary nodules (in 33 patients) using self-made, platinum microcoils. Patients in which PCNA results were less likely to be non-diagnostic and who were anticipating thoracoscopy were eligible to participate in this study. The CT-guided PCNA biopsy and microcoil localization was performed on the day of the VATS in the CT suite. The PCNA specimen was sent to the pathologist for frozen section pathology. If diagnosis of the lesion was not confirmed by PCNA or was primary lung cancer, the patient was moved to the operating room for VATS surgery. RESULTS: Between Jan 2006 and Dec 2013, concomitant PCNA and localization were successfully performed on 34 pulmonary nodules from 33 patients (one patient had two nodules). Of the 34 nodules, seven were diagnosed pathologically using PCNA, and 27 nodules that could not be diagnosed by PCNA were excised by thoracoscopic resection without additional procedures or time because of concomitant localization. There were no deaths or significant morbidities. Minor complications included three incidents of lung hemorrhage and five of pneumothorax (two required closed thoracostomy drainage). Of 34 nodules in which both PCNA and localization were used, thoracoscopic resections were performed on 33, lobectomies were performed concomitantly with thoracoscopic resection on 11. Intraoperative fluoroscopy was used to detect 33 of 34 nodules localized using the platinum microcoil (97.06 %) or to guide stapling during thoracoscopic resection. CONCLUSIONS: The advantages of this technique are 1) there is no need for further localization during thoracoscopy even in cases of unsuccessful PCNA, 2) it is more effective with respect to both cost and time, and 3) it provides greater patient comfort.

Integration of gene-expression profiles and pathway analysis in ascending thoracic aortic aneurysms.

BACKGROUND: Despite the increasing incidence of ascending thoracic aortic aneurysms, their pathogenesis and molecular mechanisms remain unknown. The aim of this study was to identify the biological pathways of genes that are expressed differentially in ascending aortic aneurysms. METHODS: Aneurysm wall tissues were obtained from thoracic aortic aneurysms during their repair and normal thoracic aortas from organ transplant patients. The differential expression of genes was analyzed by NimbleGen microarrays. The biological pathways and processes were identified using Kyoto Encyclopedia of Genes and Genome pathway analysis and gene ontology analysis. RESULTS: Among 45,034 genes, 95 were differentially expressed (>two-fold change compared with control). A total of 76 genes were up-regulated and 19 genes were down-regulated in patients with ascending thoracic aneurysm. Analysis of the Kyoto Encyclopedia of Genes and Genomes pathways revealed 26 biologically functional pathways in the following categories: focal adhesion, cell junctions, peroxisome proliferator-activated receptor signaling pathway, extracellular matrix-receptor interaction, T-cell-receptor signaling pathway, B-cell-receptor signaling pathway, and regulation of the actin cytoskeleton. Differentially expressed genes were associated with 123 different gene ontology biological processes: transport, signal transduction, inflammatory response, chemotaxis, and immune response. CONCLUSION: We identified that differentially expressed genes are associated with the pathways that are mainly involved in interactions between cells and the extracellular matrix, and with immune function. The reported data provide useful information on the molecular mechanisms underlying the formation of ascending aortic aneurysms.