Number of lymph nodes dissected and upstaging rate of the N factor in robot-assisted thoracic surgery versus video-assisted thoracic surgery for patients with cN0 primary lung cancer.

PURPOSE: The accuracy of lymph node (LN) dissection in robotic surgery for lung cancer remains controversial. We compared the accuracy of LN dissection in robot-assisted thoracic surgery (RATS) vs. video-assisted thoracic surgery (VATS). METHODS: The subjects of this retrospective analysis were 226 patients with cN0 primary lung cancer who underwent robot-assisted or video-assisted thoracic lobectomy with LN dissection, in our department, between April, 2016 and February, 2021. We compared the numbers of all LNs and mediastinal LNs dissected, the time required for LN dissection, complications, and upstaging rates of the N factor between the groups. Furthermore, we performed an inverse probability of treatment weighting-adjusted analysis to reduce potential bias between the groups. RESULTS: The number of dissected LNs was higher in the RATS group in both the unweighted and weighted analyses. The time required for lymph node dissection was also longer in RATS. There was no significant difference in complications or in the upstaging rate of the N factor between the groups. CONCLUSION: More LNs were dissected with RATS. Thus, the usefulness of robot-assisted surgery for LN dissection needs to be investigated further.

[Minimally Invasive Robot-assisted Thoracoscopic Surgery for Mediastinal Tumor].

Robot-assisted thoracoscopic surgery( RATS) and video-assisted thoracoscopic surgery are minimally invasive surgical approaches to the chest wall that avoid sternotomy. We report on the innovations in RATS mediastinal tumor surgery performed in our department. We use a lateral approach, and the robotic arm is inserted between the third, fifth, and seventh intercostals and below the costal ribs. Carbon dioxide gas is insufflated using a pneumoclear insufflator. A small thoracotomy is made in the fifth intercostal space and an Alnote Lapsingle is placed and a scope and assistant port are implanted. The Alnote Lapsingle is used to keep the chest wall airtight and stable. The scope is moved less, reducing interference with the assistant. Tissue can now be placed in the retrieval bag with a good surgical field of view. After much trial and error, RATS mediastinal tumor surgery can now be performed more easily.

[Crucial Techniques for Chest Tube Placement and Postoperative Management].

Postoperative management of thoracic surgery with an indwelling chest tube is common, and knowledge about it is essential. A postoperative chest tube has four roles:1) to reinflate the lung, 2) to observe the condition of the thoracic cavity and acquire information regarding the outcomes, 3) to prevent complications, and 4) to treat pulmonary air leaks and empyema (chemical pleurodesis et ct). Although postoperative complications have decreased in recent years following advances in video-assisted thoracoscopic surgery( VATS) and devices such as stapling devices and vascular sealing systems (VSS), postoperative chest tube placement is still common. Therefore, a thorough knowledge of chest tube management is extremely important in thoracic surgery. Here, we have described, in detail, the management of a postoperative chest tube at our hospital.

[Novel Surgical Techniques for Lung Segmentectomy of Malignant Lung Tumors].

For a long time, lobectomy and lymph node dissection have been the standard surgery for treating non-small cell lung cancer. Recently, segmentectomy has been introduced as an alternative surgical procedure for treating early-stage lung cancer. Moreover, a growing number of segmentectomies are performed due to the increasing number of elderly patients, and the expansion of indications, including early- stage lung cancer with a ground glass nodule or peripheral nodule under 2 cm in diameter. However, the use of segmentectomy remains under debate. We have been performing thoracoscopic lung segmentectomy for malignant lung tumors since 2003. The number of surgeries has increased over the past few years, since robot-assisted lung resection of the right lobe became covered by health insurance in April 2018. In addition, lung segmentectomy is performed for lung metastases of malignant tumors in other organs. In deciding on the surgical approach, the increased technical difficulty of segmentectomy compared to lobectomy, owing to the anatomical complexity of the peripheral vessels and bronchi, needs to be considered, and novel surgical procedures and preoperative planning based on three-dimensional computed tomography( CT) images are necessary. We describe the preoperative management and surgical techniques used in approximately 250 lung segmentectomy procedures performed at our hospital up to May 2022, with no conversion to thoracotomy.

[Mullerian Cyst in the Posterior Mediastinum Resected by Robot-assisted Thoracic Surgery:Report of a Case].

Mullerian cyst in the posterior mediastinum is a rare disorder. We report on the case of a woman in her 40s with a cystic nodule which is located in the right posterior mediastinum next to the vertebra at the level of tracheal bifurcation. The tumor was suggested to be cystic by preoperative magnetic resonance imaging (MRI). The tumor was resected with robot-assisted thoracic surgery. Pathology by hematoxylin-and-eosin (H&E) revealed a thin-walled cyst lined by ciliated epithelium without cellular atypia. The diagnosis of Mullerian cyst was confirmed by immunohistochemical staining which showed the positive findings for estrogen receptor (ER) and progesterone receptor of the lining cells.

Anatomy of the left subsuperior segment for segmentectomy.

PURPOSE: The subsuperior segmental bronchi (B*) forms the subsuperior segment (S*) between the superior (S6) and basal segment (S7, S8, S9, S10) of the lung. However, the anatomical planes of S* remains undefined. The present study clarified the anatomical features of S*. METHODS: We reviewed the anatomical patterns of pulmonary vessels and the left lung bronchus in 539 patients using three-dimensional computed tomography. We report the anatomic structure in S*. RESULTS: A total of 537 patients were analyzed. B* was observed in 129 (24.0%) patients. The intersegmental vein between S6 and S* was complete in all cases. The absence of intersegmental veins of S* was observed in 77 (14.3%) patients, reaching 59.7% of B* cases. Twenty-two (4.1%) cases of B* diverged from the trunk of the basal bronchus, and about half of the B* branched to the dorsolateral (n = 77, 14.3%) or dorsal (n = 2, 0.37%) direction. CONCLUSION: Our study revealed the branching patterns of B* and anatomical intersegmental veins of S*. Our results provide useful information regarding anatomical segmentectomy including or adjusting to the left S*.

Pulmonary vessels and bronchus anatomy of the left upper lobe.

PURPOSES: The bronchopulmonary vascular bifurcation patterns in the upper lobe of the left lung are diverse. Therefore, it is important for general thoracic surgeons to understand the detailed anatomy of the pulmonary segments when performing thoracoscopic anatomical pulmonary resection. This study aimed to analyze the bronchovascular patterns of the left upper lobe and summarize the anatomical information associated with pulmonary anatomical pulmonary resection. METHODS: We reviewed the anatomical patterns of pulmonary vessels and the left lung bronchus of 539 patients using computed tomography imaging data including those obtained using three-dimensional computed tomography. We herein report the anatomic structure in the left upper lobe. RESULTS: Regarding the superior division bronchi, a pattern of trifurcation into B1+2, B3, lingular division bronchus was observed in nine patients (1.7%). A pattern of proximal bifurcation of B4 was found in eight patients (1.5%). Regarding the lingular veins (LV), patterns of LV drainage into the left lower pulmonary vein were observed in 22 patients (4.1%). Regarding the pulmonary artery, mediastinal lingular arteries (MLA) were found in 161 patients (29.9%). CONCLUSION: The bifurcation patterns of the bronchovascular region in the upper lobe of the left lung were clarified. These results should be carefully noted when performing anatomical pulmonary resection.

[Thoracoscopic Superior and Subsuperior Segmentectomy of the Right Lower Lung for Lung Cancer].

The subsuperior segment (S*) is not frequently observed between the superior (S6) and posterior basal segments (S10). We present a case of video-assisted thoracoscopic surgery of S6+S* segmentectomy for a primary lung cancer patient. A 71-year-old man with a 20-mm nodule on the right S6, suspected of primary lung cancer( cT1bN0M0, stageⅠA2), was admitted to our hospital. Three-dimensional chest computed tomography (CT) revealed a subsuperior segmental bronchus (B*), originating from the common trunk of the lateral basal segmental bronchus( B9) and posterior basal segmental bronchus (B10). In order to obtain enough surgical margin, we performed S6+S* segmentectomy. The pathological diagnosis was invasive adenocarcinoma( pT1cN0M0, stageⅠA3). S* segmentectomy was considered to be useful method to ensure sufficient surgical margin when the lesion is in S* or in segments adjacent to it.

Efficacy of Automatic Retention Pressure of a Double-Lumen Tube Cuff: An Artificial Intubation Model.

BACKGROUND: The movement of a double-lumen endotracheal tube (DLT) out of its appropriate position during thoracic surgery can result in the loss of one-lung ventilation (OLV), especially during pulmonary resection and node dissection. Our study aimed to validate the efficacy of automatic retention pressure control of the DLT bronchial cuff in maintaining OLV in an artificial intubation model. MATERIALS AND METHODS: A 35-Fr left-sided DLT was intubated to the left main bronchus in an intubation simulator and connected to an anesthesia machine. The inspiratory volume, respiratory rate, and inspiratory-expiratory ratio were set at 500 mL, 12 times/min, and 1:2, respectively. A 1-kg right main bronchial traction in the lateral right was provided after OLV was established. SmartCuff (Smiths Medical, Minneapolis, Minnesota, USA) was used to maintain cuff pressure. The efficacy of retention pressure with SmartCuff (Group S) and without SmartCuff (Group WS) was compared. The primary outcome was the rate of tidal volume (TV) reduction following bronchial traction in the two groups. RESULTS: The TVs were 289.8 ± 28.9 mL and 242.8 ± 31.9 mL in Group S and Group WS, respectively (P = 0.003). The rate of TV reduction after bronchial traction was significantly lower in Group S (29 ± 5%) than in Group WS (43 ± 6%) (P < 0.001). CONCLUSIONS: Automatic retention pressure control of the DLT bronchial cuff improves the rate of TV reduction during right main bronchial traction in an artificial intubation model. Continuous retention cuff pressure may be useful in maintaining OLV during thoracic surgery.

Treatment of air leakage using the VIO soft coagulation system: a mouse pulmonary air leak model.

PURPOSE: We aimed to compare the efficacy of the VIO soft coagulation system (VSCS) for the treatment of air leaks by sealing with fibrin glue, and also assess the histological alterations that occur after soft coagulation. METHODS: A mouse pulmonary air leak model was designed. The pulmonary fistula was subsequently coagulated with the VSCS or sealed with fibrin glue with polyglycolic acid (PGA) sheets. The burst pressure at air leak recurrence was measured in each group, and the results were compared. We also evaluated the histological alterations in the mouse pulmonary air leak model after soft coagulation with the VSCS. RESULTS: The burst pressure in the soft coagulation group (80 W/Effect 5) (median 42.8; range 35.4-53.8 cmH2O) was similar to that in the fibrin glue group (median 41.5; range 34.6-43.9 cmH2O) (p = 0.21). Histological examinations revealed that the visceral pleura remained torn, the structure of the pulmonary alveolus was maintained, and the coagulated fistula was covered with a fibrin membrane in the soft coagulation group. CONCLUSIONS: The pressure resistance following soft coagulation was equivalent to that after sealing using fibrin glue with PGA sheets. The air leaks were likely controlled by covering the fistula with a fibrin membrane after soft coagulation with the VSCS.

[Thoracoscopic Pulmonary Resection in Lung Cancer Patients with Pleural Adhesion].

When a presence of significant pleural adhesion is identified at the beginning of surgery, multiple factors determine the outcome of the surgery, particularly when it is performed thoracoscopically. These factors include identification of adhesion at the beginning of the surgery, as well as procedures involved in dissection and additional incisions. If the adhesion is partial, the lack of observation during creation of the surgical field can lead to damage being caused outside the field of view due to traction. Thus, it is important to focus observations. At our department, we started performing thoracoscopic surgery in 1992. Currently, over 80% of annual surgical cases are performed thoracoscopically. We will review our thoracoscopic surgery cases that involved pleural adhesion and discuss the tools and techniques used, as well as providing additional tips for ensuring successful thoracoscopic surgery.

[Congenital Pericardial Defect Incidentally Found at Thoracoscopic Left Upper Lobe Resection:Report of a Case].

We report a rare case of a congenital pericardial defect that was incidentally found at thoracoscopic left upper lobe resection in a patient with lung cancer. A 75-year-old man with a left upper lobe lung cancer was referred to our hospital. We performed thoracoscopic left upper lobectomy and incidentally found a pericardial defect intraoperatively. Careful lymph node dissection was necessary to avoid injury of phrenic nerve and pulmonary artery. Surgery for lung cancer was completed without pericardial repair. After surgery, no complications associated with the pericardial defect has not been encountered.

[Probable Immunoglobulin G4 (IgG4)-related Periaortitis Requiring Differentiation from Mediastinal Tumor].

A 42-year-old man with a history of suspected of Behcet's disease underwent oral steroid treatment. During follow-up, chest X-ray revealed an abnormal shadow of the mediastinum. Chest computed tomography(CT) showed a circumferential tumor around the descending thoracic aorta. Enhanced CT showed a lowly and uniformly enhanced tumor at delay phase. A mediastinal tumor was suspected, which prompted a biopsy of the periaortic tumor by video-assisted thoracic surgery (VATS). Histopathological diagnosis showed numerous immunogloblin G4 (IgG4)-positive plasma cells suggesting the possibility of IgG4-related periaortitis. However, based on the diagnostic criteria, the case was comprehensively diagnosed as probable IgG4-related periaortitis, steroid treatment may have affected blood IgG4-positive cells and tissues.

Pulmonary vessels and bronchial anatomy of the left lower lobe.

PURPOSE: To identify and clarify the comprehensive anatomic patterns in the left lower lobe (LLL). METHODS: Using computed tomography (CT) imaging data, including that obtained using three-dimensional CT, we reviewed the anatomic patterns of the pulmonary vessels and bronchi in the left lungs of 539 patients, focusing on the LLL. RESULTS: The two-stem type in A6 was observed in 131 (24.7%) patients and the three-stem type in A6 was observed in 11 (2.1%) patients. The independent two-stem type in B6 was observed in four (0.75%) patients. The B7 with independent branching from the basal bronchi was observed in 42 (7.9%) patients. B* was observed in 129 (24.0%) patients and B* was accompanied by A* in all patients. An extrapericardial common trunk of the left pulmonary veins was identified in five patients (0.93%). CONCLUSION: We identified various bronchovascular patterns in the LLL of a large number of patients. Our results provide useful information for anatomic pulmonary resection, especially segmentectomy.

[Left Upper Lobectomy Followed by Left Lower Pulmonary Vein Reconstruction after Miscutting the Common Trunk of the Left Pulmonary Veins].

A 65-year-old woman was diagnosed with lung cancer on the left upper lobe. During thoracoscopic left upper lobectomy, the common trunk of pulmonary vein was mistaken for the left upper pulmonary vein and divided incorrectly. Instead of left pneumonectomy, we successfully performed pulmonary vein reconstruction. As a result of anticoagulant therapy for 1 month, postoperative course was uneventful.

[Successful Robotic Resection of Left Upper Mediastinal Tumor].

A man was diagnosed with a left upper mediastinal mass. The mass was located near the left subclavian vein, phrenic nerve, vagus nerve, left subclavian artery, and left brachiocephalic vein. He underwent a robotic surgery without additional approaches such as cervical approach on transmanubrial approach. Robotic surgery enabled to remove the tumor safely due to the highly flexible robot forceps under a 3-dimensional visual field. Robotic surgery may be effective for tumors in the upper mediastinum, where important blood vessels and nerves are closely present.

[Paraffinoma with Spinal Paralysis 40 Years After Pleural Plombage for Tuberculosis].

Paraffin had been used for pleural plombage in the treatment of tuberculosis. However, paraffin use has been reported to cause late postoperative complications. A 79-year-old man was presented with an extramedullary tumor and spinal paralysis. Forty-seven years ago, he had undergone pleural plombage using paraffin for the treatment of pulmonary tuberculosis. Since the extramedullary tumor was found to be paraffinoma, paraffin in the vertebral canal and thoracic cavity was removed surgically. All the paraffin in the vertebral canal and thoracic cavity was removed. After surgery, the patient remains well, without spinal paralysis.

[Surgical Treatment for Pneumopyothorax Secondary to Pancreatic Fistula].

A 46-year-old woman with cervical cancer with multiorgan metastasis visited our hospital. She underwent a total gastrectomy, splenectomy, distal pancreatectomy, left adrenalectomy, and left partial diaphragmatic resection. Postoperatively, she developed pleural effusion with high level of amylase secondary to a pancreatic fistula, consequently causing left-sided empyema. She developed acute respiratory distress syndrome. Urgent surgical treatment was scheduled, and left lower lobectomy, with diaphragmatic partial resection were performed under the venovenous extracorporeal membrane oxygenation. After surgery, intensive care for 45 days was necessary and she was discharged home 6 months post operatively.

[p40 Negative Basaloid Squamous Cell Carcinoma of the Lung;Report of a Case].

Immunohistochemical staining is important for the differential diagnosis of basaloid squamous cell carcinoma(BSC)and other similar carcinomas, such as small-cell carcinomas and large-cell neuroendocrine carcinomas. p40 is a useful marker of squamous cell carcinoma that can be used for the diagnosis of BSC. We present the case of a 64-year-old man who was referred to our hospital for investigation of an abnormal shadow revealed on chest radiography. Computed tomography(CT) revealed a 16×11 mm nodule in the left lung(S1+2), and a thoracoscopic left upper lobectomy was performed. Histologically, lobular pattern with peripheral palisading was observed and the immunohistochemical staining revealed the tumor cells to be positive for p63 and negative for both p40 and neuroendocrine markers, leading to the diagnosis of BSC.

Video-assisted thoracoscopic surgery node dissection for lung cancer treatment.

PURPOSE: Mediastinal node dissection (MND) is an integral component of the surgical treatment for non-small cell lung cancer (NSCLC). Although video-assisted thoracoscopic surgery (VATS) has been used increasingly for lung cancer treatment, the accuracy of by VATS MND still remains controversial. We reviewed the surgical results of VATS MND for NSCLC. METHODS: A systematic review of literature was performed, and articles that fully described the surgical procedure, devices, and results of VATS MND were selected to compare the efficacy of MND by VATS and thoracotomy. RESULTS: Various techniques and equipments have been shown to perform adequate MND, but there is an argument as to the method of estimation of the accuracy of MND. Most of the recent studies showed that the nodal upstaging and number of dissected nodes are significantly lower by VATS than after thoracotomy. Oppositely, some studies showed VATS noninferiority in these issues. Complications such as chylothorax, pleural effusion, bleeding, and nerve damage were similar in both groups. CONCLUSIONS: Although ND by VATS remains controversial, VATS MND is becoming easier and more feasible owing to the development of more advanced endoscopic cameras and equipments. We should learn further to become more adept at performing adequate ND by VATS.