鈴木 秀海

BACKGROUND: The mechanism of vascular remodelling in pulmonary arterial hypertension (PAH) remains unclear. Hence, defining the origin of cells constituting intractable vascular lesions in PAH is expected to facilitate therapeutic progress. Herein, we aimed to evaluate the origin of intractable vascular lesions in PAH rodent models via bone marrow (BM) and orthotopic lung transplantation (LT). METHODS: To trace BM-derived cells, we prepared chimeric rats transplanted with BM cells from green fluorescent protein (GFP) transgenic rats. Male rats were transplanted with lungs obtained from female rats and vice versa. Pulmonary hypertension was induced in the transplanted rats via Sugen5416 treatment and subsequent chronic hypoxia (Su/Hx). RESULTS: In the chimeric Su/Hx models, GFP-positive cells were observed in the pulmonary vascular area. Moreover, the right ventricular systolic pressure was significantly lower compared with wild-type Su/Hx rats without BM transplantation (P = 0.009). PAH suppression was also observed in rats that received allograft transplanted BM transplantation. In male rats that received LT and Su/Hx, BM-derived cells carrying the Y chromosome were also detected in neointimal occlusive lesions of the transplanted lungs received from female rats. CONCLUSIONS: BM-derived cells participate in pulmonary vascular remodelling in the Su/Hx rat model, whereas BM transplantation may contribute to suppression of development of PAH.

OBJECTIVE: Intrathoracic negative-pressure wound therapy (NPWT) has been introduced as a novel therapeutic device for the management of empyema. NPWT is expected to reduce the empyema cavity more rapidly than standard treatments; however, no objective analysis of the function of NPWT has yet been conducted. The study objective was to evaluate the efficacy of NPWT in the management of thoracic empyema. METHODS: Ten patients with stage II or III thoracic empyema treated with NPWT were retrospectively analyzed. The volume of the empyema cavity was measured, and the volume change after the administration of NPWT was calculated. A comparison with the institutional historical controls was also performed. RESULTS: The patients had initially undergone fenestration of the chest wall for empyema, and eight had bronchopleural fistula and required procedures to close the fistula. The mean duration of NPWT was 71.1 days (4-190 days). The mean volume of the empyema cavity decreased from 230.2 ml (42.8-788.4 ml) to 78.5 ml (5.2-185.3 ml) by applying NPWT (P = 0.02), and the mean % decrease was 58.7% (0-87.9%). Ultimately, the empyema cavity was able to be cleaned in nine, including seven who were cured by subsequent thoracoplasty and two who were cured without thoracoplasty. The current study group had a tendency toward an early cure with less chest wall destruction, a less hospital stay after open window thoracotomy compared to historical control. CONCLUSIONS: NPWT enables the effective volume reduction and cleaning of the empyema cavity and achieves an early cure and reduced destruction of the chest wall.

肺癌骨転移例で、主科(呼吸器内科または呼吸器外科)から当科に対して骨生検検体による遺伝子検索の依頼があった9例10検体の検索結果を報告した。検体採取部位の内訳は、腰椎椎弓根が4検体、腸骨3検体、胸椎椎弓根2検体、胸椎横突起1検体であった。病変の組織採取ができたのは9検体で、いずれも病理組織学的に癌細胞が確認された。病変組織を採取できなかった1検体は、骨修飾薬投与に伴う病変部の骨硬化が強いため生検針を病変に到達させることができなかった。遺伝子検査を実施した9検体中4検体にEGFR遺伝子変異が認められ、うち2例はT790Mが陽性であった。9例とも骨生検結果の報告後に主科で治療方針の検討が行われ、T790M陽性の2例はいずれも抗悪性腫瘍薬がゲフィチニブからオシメルチニブメシル酸塩へ変更となった。

PURPOSE: The sampling and accurate diagnosis of lymph nodes during the clinical history of lung cancer are essential for selecting the appropriate treatment strategies. This study aims to evaluate the feasibility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in patients with previously treated lung cancer. METHODS: Patients who underwent EBUS-TBNA after treatment for lung cancer were retrospectively reviewed. We classified the patients into two groups; Group 1 (G1): Indicated to have a recurrence of new lesions after radical surgery or chemo/radiotherapy with a curative intent; and Group 2 (G2): Indicated to have residual tumor cells after undergoing primary treatment for chemo/radiotherapy or re-staging after induction therapy prior to surgery. RESULTS: Seventy previously treated lung cancer cases (G1, n = 52; G2, n = 18) were enrolled. Thirty-two cases (61.5%) had recurrent disease in G1, and 9 cases (50.0%) had nodal metastasis in G2. The diagnostic accuracy was 95.2% in G1 and 88.9% in G2. Twenty-four cases were examined for epidermal growth factor receptor (EGFR) mutations, and 9 (37.5%) cases had mutations, including two cases with a T790M mutation. Furthermore, in one case, a re-biopsy revealed that the initial adenocarcinoma had transformed into small cell lung cancer. CONCLUSION: Performing EBUS-TBNA during lung cancer treatment showed a high diagnostic yield. Samples obtained by EBUS-TBNA were helpful in determining when to perform repeat biomarker testing as well as for making pathological re-evaluations.

PURPOSE: The aim of this study was to evaluate the ability of fluorine-18-fluorodeoxyglucose positron emission tomography coupled with computed tomography (18F-FDG-PET/CT) to predict the WHO malignancy grade, initial staging, and invasive potential of thymic epithelial tumors. METHODS: We retrospectively reviewed the medical records of 56 patients with thymic epithelial tumors who were evaluated by PET/CT before surgery and underwent surgical resection. We analyzed the relationship of the maximum standardized uptake value (SUVmax) with the WHO histological classification, tumor invasion, TNM classification, and the Masaoka-Koga classification. RESULTS: There were differences of SUVmax of the FDG-PET between thymic carcinoma (9.09 ± 3.34) and thymoma (4.86 ± 2.45; p < 0.01), thymic carcinoma (9.09 ± 3.34) and high-grade thymoma (6.01 ± 2.78; p < 0.01), and high-grade thymoma (6.01 ± 2.78) and low-grade thymoma (4.06 ± 1.86; p < 0.01). The cut-off value for the SUVmax was 7.40 and 5.40, and the sensitivity/specificity for predicting the histologic subtype of each group was 0.72/0.79 and 0.61/0.85, respectively. According to T classification, SUVmax was significantly higher in T3 (8.31 ± 2.57) than in T1a (4.45 ± 2.06; p < 0.01). Regarding Masaoka-Koga classification and WHO histological classification, a significantly higher SUVmax was detected in patients with stage III and IV disease than in those with stage I and II diseases (p < 0.01). The cut-off value for SUVmax was 5.40 in Masaoka-Koga stage and 5.60 in the WHO classification; the sensitivity/specificity for predicting the histologic subtype was 0.85/0.80 and 0.89/0.78, respectively. CONCLUSIONS: FDG-PET is a useful tool to predict aggressiveness of thymic epithelial tumors.

BACKGROUND: Knowledge of anatomical abnormalities and variations in pulmonary vessels and bronchi is critical for patients requiring a lung segmentectomy. To the best of our knowledge, this is the first case of a tumor existing in the lower lobe in conjunction with a displaced B1+2 in which the B1+2 was not accidentally cut during surgery. CASE PRESENTATION: A 71-year-old woman was referred to our hospital after a part-solid lung cancer was found in the superior segment of her left lung on chest computed tomography. Preoperative three-dimensional computed tomography revealed a displaced anomalous left B1+2 arising from the left main bronchus and anomalous V1+2 returning to the inferior pulmonary vein. We identified these anomalies during surgery and performed a left superior segmentectomy. After an unremarkable recovery, the patient was discharged from the hospital on the eighth day postoperative. CONCLUSIONS: We used a three-dimensional construction system during the preoperative planning of the pulmonary segmentectomy to better understand the bronchovascular structures. When performing surgery where anatomical abnormalities are present, there is the possibility of misidentification. Using the three-dimensional construction system, it was possible to perform safer surgery, as the surgeons were able to preoperatively prepare for any abnormalities.

Pulmonary arteriovenous malformation (PAVM) is a potential cause of hemothorax. The risk of PAVM rupture is reported to be higher during pregnancy for several reasons, including increased body fluid and a change in hormonal conditions. A 34-year-old pregnant woman suddenly felt right chest pain and dyspnea in the 28th week of gestation. Chest X-ray and computed tomography showed massive right pleural effusion. Her vital signs gradually deteriorated with hemorrhagic shock, necessitating emergency surgery. During exploratory thoracoscopy, active bleeding from the middle lobe was noticed and gauze packing was required to maintain her blood pressure. Following conversion to major thoracotomy, wedge resection of the middle lobe was performed with a linear stapler, and finally, her general condition became stable. Her postoperative course was uneventful. A histological examination of the resected specimen confirmed the diagnosis of ruptured PAVM. Her baby was successfully delivered at the 38th week of gestation.

The treatment of acute pulmonary thromboembolism with a hemorrhagic condition is quite challenging and it usually presents a clinical dilemma. Pulmonary embolectomy is generally performed with cardiopulmonary bypass; however, cardiopulmonary bypass usually requires full anticoagulation which cannot be used for patients with a hemorrhagic condition. We herein report a successful case of pulmonary embolectomy that was accomplished using central veno-arterial extracorporeal membranous oxygenation, instead of cardiopulmonary bypass, for a patient with an acute fatal pulmonary thromboembolism and hemorrhagic cerebral infarction following lung cancer surgery. Our strategy consists of surgical embolectomy under central veno-arterial extracorporeal membranous oxygenation with partial anticoagulation and the placement of an inferior vena cava filter to prevent recurrence without the use of anticoagulation therapy.

Background: Spontaneous pneumothorax is common in relatively young, healthy patients. The risk factors for postoperative recurrence after correction are not fully understood. Methods: We retrospectively reviewed the records of patients who underwent surgery for spontaneous pneumothorax between January 2006 and October 2017. We assessed the possible factors causing postoperative recurrence using univariate and multivariate analyses. We then used the inverse probability of treatment-weighted method to correct for confounding factors. Results: Postoperative recurrence was observed in 41 of 233 patients (17.6%). A significant association with recurrence was noted for primary spontaneous pneumothorax (PSP), never smokers, thoracoscopic surgery, patients younger than 30 years, operative time less than 100 minutes, and surgery by a resident surgeon. Patients younger than 30 years of age had a 5-year recurrence-free probability of 46.3%. On multivariate analysis, patients younger than 30 years was an independent risk factor for recurrence. The confounding factors for recurrence of PSP included patients younger than 30 years, surgery by a resident surgeon, and thoracoscopic surgery. After adjusting for confounders, patients younger than 30 years was the only factor associated with recurrence (P=0.015). Patients who underwent bulla ligation with pleural reinforcement using an absorbable polyglycolic acid (PGA) sheet had a 4% recurrence rate and a 5-year recurrence-free probability of 90.0%. Conclusions: Patients younger than 30 years of age is a significant factor for postoperative recurrence in patients with PSP. Surgeons may attempt to prevent postoperative recurrence by devising the operative method and pleural reinforcement methods.

＜文献概要＞はじめに 2018年版の肺癌診療ガイドラインでは,「cT4N0〜1非小細胞肺癌に対して,外科切除を行うよう提案する(推奨の強さ:2,エビデンスの強さ:D)」となっている.日本胸部外科学会から2005〜2016年の肺癌切除例と隣接臓器合併切除または椎体合併切除の頻度と30日死亡率・院内死亡率が報告されている(表1).原発性肺癌の全体の手術症例は近年大幅に増加しているが,椎骨合併切除を伴う症例は経年的な変化に乏しく,年間11〜37例が行われている.椎体合併切除を伴う肺癌手術は整形外科医の協力と長時間手術が必要になることが予想され,術前検討を十分に行う必要がある.当院での経験をふまえて椎体合併切除を要する肺癌手術の概要について述べる.

While cases of surgical resection for primary lung cancers are increasing, lung cancer requiring vertebrectomy is rare. A high complication rate and recurrence rate have been reported after surgical resection for lung cancer with vertebral invasion. However, select patients who achieve complete resection after effective preoperative chemoradiotherapy show a better survival rate than others. Preoperative computed tomography and magnetic resonance imaging are necessary to consider surgical strategies and how to resect and reconstruct the vertebral body and chest wall with a clear margin before surgery. A 3-dimensional imaging or simulation model is useful for such ends. Several surgical approaches have been developed, such as the transmanubrial, posterior, posterolateral, or the combination thereof. Proper vertebrectomy( total, hemi, part of a vertebra, or only the transverse process of a vertebra) and reconstruction approaches should be decided in conjunction with orthopedic surgeons. While evidence is lacking, establishing proper surgical indications and developing effective strategies to achieve complete resection with a clear margin are the most critical points in lung cancer requiring vertebrectomy.