Comparison of imaging changes in pulmonary artery diameter at the occlusion site using silk or metal clamps for pulmonary artery troubles.

OBJECTIVES: We analysed our clinical experience using silk sutures [the double-loop technique (DLT)] or DeBakey type vascular clamp (DeBakey clamp) for pulmonary artery (PA) troubles during anatomical lung resection to validate its practicality and safety. METHODS: We retrospectively reviewed the records of patients who underwent either of the above clamping techniques during anatomical lung resection at our hospital between April 2007 and August 2022. We measured the PA diameter at the occlusion site on computed tomography images acquired within 1 year pre- and postoperatively. The difference between pre- and postoperative diameters of the occlusion sites was calculated as the change in the PA diameter. We zoned the occlusion site of the PA to adjust for variation. PA deformation was evaluated as an adverse event caused by clamping. RESULTS: Ultimately, 27 and 26 patients who underwent the DLT and DeBakey clamp, respectively, were included. No additional injury due to the clamp procedure was found in either group. For zone R1/L1, defined as the main PA, the median changes in the PA diameter were 0.02 (-0.7 to 0.27) mm for the DLT and 0.36 (-0.28 to 0.89) mm for the DeBakey clamp. No significant differences were observed between the 2 groups (P = 0.106). Furthermore, no aneurysms, dissections, or stenoses were found in either group. CONCLUSIONS: The DLT and DeBakey clamp had only minimal effects on the occlusion site of the PA. The DLT is a practical thoracoscopic technique for PA bleeding when primary haemostasis has been achieved.

[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.

[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.

Experimental and histological evaluation of different clamp technique for pulmonary artery.

OBJECTIVES: The double-loop technique has been used in our clinical settings for pulmonary arterioplasty and/or injured artery repair during thoracoscopic anatomical lung resection. We evaluated the pressure resistance capacity and intimal load to determine the effectiveness and safety of the double-loop technique. METHODS: The double-loop technique, DeBakey clamp, Fogarty clamp, endovascular clips and vessel loop technique were evaluated. During an experimental study, a polyvinyl alcohol main pulmonary artery model, manometer and in-deflation device were used to measure the burst pressure. The maximum clamp pressure was measured using a pressure-measuring film. Each measurement was performed 10 times. During the histological study, we measured the burst pressure and evaluated the intimal damage of the human pulmonary artery associated with the double-loop technique and DeBakey clamp. RESULTS: The experimental burst pressure (mmHg) and maximum clamp pressure (MPa) between the double-loop technique and DeBakey at the third notch were not significantly different (24.6 ± 2.8 and 21.8 ± 2.8, P = 0.094; 1.54 ± 0.12 and 1.49 ± 0.12, P = 0.954). During the histological study, the burst pressures of the double-loop technique and DeBakey at the third notch were also not significantly different (P = 0.754). Furthermore, the double-loop technique resulted in only intimal deformation in each five samples. CONCLUSIONS: The double-loop technique is feasible for thoracoscopic anatomical lung resection because it has similar pressure resistance capacity and intimal load as DeBakey at the 3rd notch.

[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.

[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.

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.

[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.

Causes and management of intraoperative complications in robot-assisted anatomical pulmonary resection for lung cancer.

Background: To perform safe robot-assisted anatomical lung resections, the details of intraoperative complications need to be shared among thoracic surgeons. However, only limited data are available. Methods: This retrospective, single-institutional study evaluated 134 patients who underwent robot-assisted anatomical lung resection. We examined the causes, management, and outcomes of all intraoperative complications. Results: Of the 134 eligible patients, 118 (88%) underwent lobectomy and 16 (12%) underwent segmentectomy. Intraoperative complications occurred in 17 (12.7%) patients. These complications included pulmonary artery (PA) injuries in seven patients, pulmonary vein (PV) injuries in three, azygos vein (AV) injury in one, superior vena cava (SVC) injury in one, bronchial injuries in three, and lung injuries in four. Most PA injuries were at a distal side and controlled by pressure, fibrin sealant, or stapling of the proximal side. In the three PV injuries, right upper PV was sandwiched by robotic instruments, V6 was punctured by the tip of the Maryland bipolar forceps, and the distal side of V2t was injured during tunneling of a minor interlobar fissure. These were controlled the same way as the PA injuries. The AV injury occurred during hilar lymph node (LN) dissection and was controlled by suturing. The SVC injury was caused by interference of the robotic forceps and the suction tube outside the field of view during upper mediastinal LN dissection. The injury was controlled by continuous pressure while layering polyglycolic acid sheets and fibrin glue. In the three bronchial injuries, B10 was injured during subcarinal LN dissection, right main bronchus was injured during upper bronchus dissection and the stapling failure of the bronchus occurred by strong traction. They were all repaired by suturing. All lung parenchymal injuries were caused by manipulation of robotic instruments outside the field of view. The lung injuries were repaired by suturing with pledgets. No cases were converted to thoracotomy. The 30-day mortality rate was 0.7%. The cause of mortality was pneumonia. Conclusions: In robot-assisted anatomical pulmonary resection for lung cancer, most major intraoperative complications can be safely managed robotically without conversion to thoracotomy.

Robot-assisted and video-assisted thoracoscopic surgery for thymoma: comparison of the perioperative outcomes using inverse probability of treatment weighting method.

Background: Minimally invasive surgery is the standard treatment for early-stage thymoma. We compared the perioperative outcomes between robot-assisted thoracoscopic surgery (RATS) and video-assisted thoracoscopic surgery (VATS) for thymoma. Methods: Between April 2011 and August 2021, patients with thymoma who underwent thymectomy by RATS (n=20) or VATS (n=37) at our hospital were retrospectively reviewed. We evaluated the postoperative quality of life (QOL), surgical outcomes, complications, mortality, and pain grade. Postoperative QOL was assessed according to the time to achieve "B duration" and "CIII duration" based on the Nursing Dependency Score and Nursing Criteria, respectively. Results: After the inverse probability of treatment weighting (IPTW), the B duration and CIII duration were significantly shorter with RATS than with VATS (P<0.001 and P=0.037, respectively). These superior results of RATS group compared to those of the VATS group were confirmed with logistic regression analysis (OR 0.25, 95% CI: 0.10-0.63, P=0.003; and OR 0.31, 95% CI: 0.12-0.76, P=0.011, respectively). After the IPTW, the VATS group had significantly fewer patients with epidural analgesia than the RATS group (P=0.018). In contrast, additional regular analgesics (including those for wound pain and neuralgia) were prescribed significantly more often during postoperative hospitalization in the VATS group (P=0.033). Patients in both groups had no myasthenic crisis or mortality. The postoperative pain grade at the first and second follow-ups did not significantly differ between the two groups after the IPTW (P=0.376 and P=0.109, respectively). Conclusions: RATS offered the advantages of improved postoperative QOL according to nursing care systems compared to VATS.

[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.