Published papers

Background: Alveolar air leakage from a pleural defect around the staple line is one of the complications after wedge resection of the lung. An intraoperative closure of the pleural defect by suturing can cause additional pleural rupture due to tension of the pleura adjacent to staple lines. Therefore, we have introduced a novel closure method for pleural defect adjacent to the staple line, named the double stapling method. This study compared the efficacy of two closure methods; the double stapling method and conventional suturing method with pledgets using ex vivo porcine lungs. Methods: The double stapling method involves closing the pleural defect by suturing the two parallel staple lines at both sides of the pleural defect. This method was developed to distribute the pleural tension around the needle holes of suturing. As a model of pleural defect adjacent to the staple line after wedge resection, wedge resection of the caudal lobe of left porcine lungs was performed, and a superficial square pleural defect (10 mm × 10 mm) adjacent to the staple line was made by scalpel. The defect was closed using the following two methods: (I) suturing with pledgets (n=10); and (II) double stapling method (n=10). The lobe was inflated in water at an airway pressure of 20, 25, and 30 cmH2O; closure success or failure was judged by the absence or presence of air leakage. Results: The closure success was confirmed in 2 (20%) out of 10 cases in the suturing with pledgets group and 9 (90%) out of 10 in the double stapling method group (P=0.007). In 4 out of 10 cases in the suturing with pledgets group, new pleural clefts longer than 3 mm were created around the needle holes of suturing. Conclusions: Ex vivo experiments have suggested the superiority of the double stapling method for the intraoperative closure of alveolar air leakage adjacent to the staple line after wedge resection, compared to conventional suturing with the pledget method.

Coil embolization is widely performed for pulmonary arteriovenous malformations (PAVMs). We describe herein 2 cases of hemoptysis during long-term follow-up after coil embolization for PAVMs. For both cases, lobectomy was performed and histopathological examinations revealed chronic inflammation and bronchial epithelium extension into the sac of the PAVM. In addition, we performed a systematic review of previous reports of hemoptysis after embolization for PAVMs.

Background: In our institution, computed tomography (CT)-guided percutaneous cryoablation has been performed in patients with malignant lung tumors under local anesthesia. This study aimed to examine the feasibility and safety of percutaneous cryoablation for the treatment of malignant lung tumors. Methods: From July 2002 to December 2016, 227 patients (56 with primary lung cancer and 171 with metastatic lung tumor) underwent percutaneous cryoablation for the treatment of malignant lung tumors using a cryosurgical unit at our institution. Demographic factors, duration of post-treatment hospitalization, and adverse event and mortality rates were retrospectively investigated in 366 treatment sessions targeting 609 lesions. Results: The median diameter of the targeted tumor was 1.3 cm. All the cryoablation procedures were completed under local anesthesia, and the median duration of post-treatment hospitalization was two days. Adverse events (grade 2 or higher) were observed in 79 sessions (21.6%), with pneumothorax being the most common. In five sessions (1.4%), patients had grade 3 adverse events. There was no 30-day mortality; however, there were two 60-day mortality (0.5%) due to acute exacerbation of interstitial pneumonia. In multivariate analysis, independent predictors of adverse events were comorbid interstitial pneumonia [odds ratio (OR) =2.20; 95% confidence interval (CI): 1.04–4.64] and no history of pulmonary resection on the treated side (OR =3.04; 95% CI: 1.65–5.62). Conclusions: Cryoablation is a feasible and safe treatment for malignant lung tumors with acceptable adverse event rates. However, the mortality risk in patients with comorbid interstitial pneumonia should be fully recognized.

Purpose: Surgical patients with thymoma and myasthenia gravis (MG) must have their MG status and oncological outcomes critically monitored. We aimed to identify clinicopathological predictors of the postoperative MG status. Methods: We conducted a retrospective review of 40 consecutive surgical patients with MG-related thymomas between 2002 and 2020. The quantitative myasthenia gravis score (QMGS) and Myasthenia Gravis Foundation of America post-intervention status (MGFA-PIS) were used to evaluate postoperative MG status. Results: All patients underwent extended total thymectomy. The most common WHO type was type B2 (32%), while 65% of patients had type B1–B3 and 35% had type A–AB thymomas. Eleven patients (28%) achieved controlled MG status in MGFA-PIS 6 months after surgery. This controlled status was observed more frequently in type A–AB than in B1–B3 (57% vs. 12%, p = 0.007). In a multivariate analysis, WHO type (A–AB or B1–B3) was an independent predictor of worsening episodes of MG based on the QMGS (Type B1–B3, hazard ratio: 3.23, 95% confidence interval: 1.12–9.25). At the last follow-up, 23 patients (58%) achieved controlled MG status. The 5-year overall survival rate of all patients was 93.7%. Conclusion: The WHO type of thymoma is an informative predictor of postoperative MG status in patients with MG-related thymoma.

The Nuss procedure for pectus excavatum (PE) is both less invasive and very simple compared to the Ravitch procedure. However, it may be difficult to perform the Nuss procedure in cases of severe PE. Therefore, we developed a Combined Ravitch and Nuss (CRN) procedure and examined its effectiveness in patients with severe PE. Nine patients with severe PE underwent the CRN procedure. Data on patient characteristics and perioperative results were collected retrospectively. The median Haller index (HI) was 15.4 (range, 6.3-29.3). No significant intraoperative adverse events were noted. Postoperatively, marked improvements in HI were seen in all cases (3.29, range, 2.72-4.96). Two surgical site infections on the shallow layer and one wound seroma occurred. No recurrences were observed during the observation period. Our novel CRN procedure is useful for achieving adequate and sustainable sternal elevation with less invasiveness for patients with severe PE.

Pectus excavatum (PE) is often associated with scoliosis and can elicit cardiovascular disturbances under rare conditions. Here we report a patient who was treated with a combined Ravitch and Nuss procedure for PE with dyspnea following scoliosis repair to improve her symptoms. The patient was a 49-year-old woman with a history of PE and scoliosis. Right inferior pulmonary vein stenosis was caused by posterior spinal fusion for scoliosis prior to the PE repair. We could safely correct the chest wall deformity and treat dyspnea by performing a modified Ravitch repair in combination with the Nuss procedure.

40歳女性．左肺尖部に5.9 cm大の腫瘤影を認め，経皮的生検を行った所，カルチノイド腫瘍が疑われ，画像上は肺尖部胸壁浸潤癌を考え，手術の方針とした．胸腔内を観察すると腫瘍は胸壁から発生しており，胸壁腫瘍を切除した．病理では類円形核と好酸性の胞体を有する異型の弱い腫瘍細胞が増生し，形態像と免疫染色所見から胸壁発生のグロムス腫瘍と診断した．胸壁発生のグロムス腫瘍の報告は極めて少なく，文献的考察を加えて報告する．

Pectus excavatum (PE) causes cardiopulmonary dysfunction depending on the degree and form of the depression. The patient was a 74-year-old woman with a history of PE. Fourteen years ago, a total glossolaryngectomy was performed for oropharyngeal cancer. Two years later, the patient gradually experienced difficulty in breathing. Computed tomography (CT) revealed severe PE and right main bronchial stenosis. We performed a Nuss procedure for PE repair to surgically release the stenosis of the right main bronchus. Postoperative chest CT showed improvement in the sternal depression and right main bronchial stenosis. Furthermore, shortness of breath was relieved postoperatively. Oropharyngeal cancer surgery may cause tracheal support disruption, leading to leftward shift and severe stenosis of the right main bronchus due to sternum depression. This is an important report regarding respiratory distress caused by a combination of PE and post-oropharyngeal cancer surgery.

Ehlers-Danlos syndrome (EDS) is a group of hereditary diseases causing connective tissue fragility due to genetic abnormalities in collagen and its modifying enzymes. We report two surgical cases of pneumothorax associated with EDS. Case 1 was initial-onset left pneumothorax in a 43-year-old woman with a history of retinal detachment and multiple cavitary lesions of the bilateral lungs on preoperative imaging. Intraoperatively, air leakage was observed from the cavitary lesion of the left lower lobe, and wedge resection of the lung was performed. The lung tissue was extremely fragile, and additional air leakage was observed from both the grasped lung parenchyma and staple line. Additional stitches and biological tissue adhesive were needed to control the air leakage. The patient was diagnosed with classical EDS after the operation. Case 2 involved recurrent right pneumothorax in a 38-year-old woman. She had a history of perforation of the descending colon and was diagnosed with vascular EDS. Air leakage was observed from the cyst in the right upper lobe intraoperatively, and the cyst was sewn. Since the lung tissue was very fragile and another air leakage occurred from the grasped lung parenchyma, it was excised with an automatic suture device and covered with absorbent suture reinforcement. Parietal pleura scraping was added to promote intrathoracic adhesion. Although elastic fibers were pathologically maintained in the resected specimens of both cases, the lung tissues were extremely fragile. For patients with diagnosed or suspected EDS during pneumothorax surgery, it is essential to adopt protective measures that address the tissue fragility.

Micronodular thymoma with lymphoid stroma (MNTLS) is rare, accounting for 1.4% of the total cases of thymoma. We report two surgical cases of MNTLS. Case 1: The patient was a 60-year-old woman who had a 17-mm nodule in the anterior mediastinum that was revealed by chest computed tomography during a medical checkup. We performed video-assisted thoracoscopic thymectomy. Case 2: The patient was a 70-year-old woman who had an 18-mm nodule in the anterior mediastinum that was also revealed by chest computed tomography during a medical checkup. We performed video-assisted thoracoscopic thymectomy. Both resected tumors were well-defined and homogenously white in color. Histopathological findings of the tumors revealed separation by an abundant lymphoid stroma with a field of tumor cells. Immunohistochemical staining showed that the tumors were positive for pankeratin in the field of tumor cells. The histopathological diagnosis was MNTLS. The long-term outcomes after the resection of MNTLS were good in previous reports. Case 1 has survived without recurrence for four years, and Case 2 has survived without recurrence for one year and six months.

Rosai-Dorfman disease is rare and typically presents with cervical lymphadenopathy. The disease is generally indolent and self-limited, but it carries a poor or fatal prognosis when it is advanced or when it involves and compresses vital structures. We herein report a rare case of Rosai-Dorfman disease affecting only the mediastinal-hilar region in a 66-year-old woman.

We report a case of 51-year-old woman with a severely airway-obstructing leiomyoma who underwent successful tracheal resection. A preoperative tumor biopsy was avoided not to cause any risk of suffocation. At surgery, an endotracheal intubation distal to the tumor was achieved with a bronchoscopic guidance. A segmental resection of the trachea with a primary end-to-end anastomosis was performed via a half-splitting median sternotomy. Negative surgical margins for tumor were confirmed intraoperatively. Final pathological diagnosis was a primary tracheal leiomyoma. Definitive surgical resection is a treatment of choice for such airway-obstructing, wide-based leiomyoma. Although a bronchoscopic removal of the tumor is an alternative choice, the risks of suffocation, positive surgical margins, and perforation of the trachea need to be carefully discussed if it is considered.

A 45-year-old female was diagnosed as having lung adenocarcinoma harboring an anaplastic lymphoma kinase (ALK) rearrangement, stage IV (T2bN3M1b). She was treated with crizotinib as second-line chemotherapy. The clinical stage after crizotinib treatment was ycT2aN0M0, stage IB. We performed a left lower lobectomy and lymph node dissection aimed at local control and pathological confirmation of the remaining tumor. The final pathological stage was ypT2aN2M0, stage IIIA with Ef 1b. To the best of our knowledge, this is the first case report of surgical resection in ALK rearrangement-positive lung adenocarcinoma after crizotinib treatment.