Takamasa Shibasaki

Feasibility of thoracoscopic thymectomy for treatment of early‐stage thymoma

The objective of this study was to evaluate the feasibility of thoracoscopic thymectomy (TT) for treatment of early‐stage thymoma and to compare the outcomes with those after open thymectomy (OT).

Thoracoscopic thymectomy is a feasible and less invasive alternative for the surgical treatment of large thymomas

OBJECTIVES Thoracoscopic surgery is widely used for the surgical treatment of thymoma. However, large-sized thymomas are typically treated using open surgery. This study evaluated the feasibility of performing thoracoscopic thymectomy (TT) for thymoma ≥50 mm. METHODS A retrospective review was conducted on 135 patients who underwent TT or open thymectomy (OT) for Masaoka stage I-IVa thymoma between 1996 and 2014. RESULTS Patients were first divided into two groups based on thymoma size: thymoma ≥50 mm and thymoma <50 mm groups. There was no significant difference in the 5-year disease-free survival (DFS) between the groups ( P  = 0.5352). Patients in the thymoma ≥50 mm group were further subdivided into TT and OT groups. The length of postoperative hospital stay was significantly shorter in the TT group than in the OT group (5 vs 14 days, P  < 0.0001), with significantly fewer postoperative complications (6 patients vs 14 patients, P  = 0.0008). There was no significant difference in the 5-year DFS between patients with thymoma ≥50 mm in the TT and OT groups ( P  = 0.3501). Finally, patients undergoing TT were further subdivided into thymoma ≥50 mm and thymoma <50 mm groups and, no significant difference in the 5-year DFS was found between these groups ( P  = 0.6661). Masaoka stages III-IV, but not thymoma size, were an independent prognostic factor for DFS. CONCLUSIONS These results demonstrate the decreased invasiveness and feasibility of TT for large-sized thymomas.

A step-by-step development of real-size chest model for simulation of thoracoscopic surgery

OBJECTIVES For the purpose of simulating thoracoscopic surgery, we have conducted stepwise development of a life-like chest model including thorax and intrathoracic organs. METHODS First, CT data of the human chest were obtained. First-generation model: based on the CT data, each component of the chest was made from a 3D printer. A hard resin was used for the bony thorax and a rubber-like resin for the vessels and bronchi. Lung parenchyma, muscles and skin were not created. Second-generation model: in addition to the 3D printer, a cast moulding method was used. Each part was casted using a 3D printed master and then assembled. The vasculature and bronchi were casted using silicon resin. The lung parenchyma and mediastinum organs were casted using urethane foam. Chest wall and bony thorax were also casted using a silicon resin. Third-generation model: foamed polyvinyl alcohol (PVA) was newly developed and casted onto the lung parenchyma. The vasculature and bronchi were developed using a soft resin. A PVA plate was made as the mediastinum, and all were combined. RESULTS The first-generation model showed real distribution of the vasculature and bronchi; it enabled an understanding of the anatomy within the lung. The second-generation model is a total chest dry model, which enabled observation of the total anatomy of the organs and thorax. The third-generation model is a wet organ model. It allowed for realistic simulation of surgical procedures, such as cutting, suturing, stapling and energy device use. This single-use model achieved realistic simulation of thoracoscopic surgery. CONCLUSIONS As the generation advances, the model provides a more realistic simulation of thoracoscopic surgery. Further improvement of the model is needed.

Impact of the introduction of thoracoscopic lobectomy for non-small cell lung cancer: a propensity score-matched analysis

Background The present study evaluated the impact of the introduction of thoracoscopic lung lobectomy (TL) for non-small cell lung cancer at our institution. Methods This study retrospectively compared surgical and oncological outcomes in the period before and after the introduction of TL for non-small cell lung cancer. Propensity score-matched analysis was performed with respect to baseline patient variables and tumor characteristics. Results Patients were divided into two groups: those who underwent lung lobectomy in the period before (BI group, n=261) and after (AI group, n=261) the introduction of TL. The proportion of TLs at our institution increased from 1.3% in the BI group to 93% in the AI group. The AI group experienced a longer duration of surgery, lesser intraoperative blood loss, and a significantly shorter postoperative hospital stay (POHS). There were no significant differences in postoperative complications between the two groups. The median follow-up period was 50 months in both groups. No significant differences were observed between the BI and AI groups with respect to 5-year overall survival (OS) (76.1% and 71.7%, respectively; P=0.1973) and disease-free survival (DFS) (67.6% and 66.1%, respectively; P=0.4071). On multivariate analysis, pathological N1-2 status was an independent predictor of survival. AI group and TL showed no independent association with survival. Conclusions The introduction of TL represented a positive change at our institution owing to decreased invasiveness and oncological equivalence of the surgical treatment for non-small cell lung cancer.

Surgical and oncological outcomes of thoracoscopic thymectomy for thymoma

Thymoma remains the most common primary anterior mediastinal neoplasm. Surgical resection remains central to the treatment of thymoma, with thoracoscopic thymectomy (TT) being increasingly performed. This present review article aimed to summarize current studies comparing TT and open thymectomy (OT). Recently, most patients with Masaoka stage I-II thymoma have been receiving TT. This procedure is associated with a significantly shorter post-operative hospital stay, decreased intraoperative blood loss, and fewer complications compared with OT. Recurrence rates of thymoma after TT range from 0% to 6.7%, and the 5-year disease-free survival (DFS) ranges from 83.3% to 96%. The oncological outcomes of TT are comparable to that of OT. Masaoka stage and the World Health Organization (WHO) type classification are valuable predictors of the prognosis of thymoma; hence, the optimal treatment for thymoma should be performed according to these two. TT is less invasive, with equivalent oncological outcomes, when compared with the OT. Minimally invasive surgery including TT for stage I-II thymomas is becoming the mainstay of therapy.