Comparison of lobectomy performed through Toumai® surgical robot and da Vinci surgical robot in early-stage non-small cell lung cancer: a retrospective study of early perioperative results.

Background: Robotic-assisted thoracic surgery (RATS) is a safe and efficient minimally invasive thoracic approach compared to thoracotomy. Today, almost all thoracic procedures can be performed by RATS. In recent years, the Chinese government has issued some policies to support the development of domestic surgical robots, leading to the development of the Toumai® surgical robot system. This study aimed to explore the application of the Toumai® surgical robot in performing lobectomy for early-stage non-small cell lung cancer (NSCLC), and to compare its safety, surgical effect, and advantages or disadvantages compared with the mature da Vinci robotic surgical system. Methods: Patients with early-stage NSCLC undergoing robotic-assisted lobectomy in our center between November 2021 and December 2021 were enrolled in the study; Surgeries were performed through the Toumai® surgical robot and the da Vinci robotic system. Anatomical lobectomy and systematic lymph node (LN) dissection were conducted in all patients. Baseline and perioperative outcomes were analyzed to compare the two methods. Results: The combined 19 patients from the Toumai® group (n=9) and the da Vinci group (n=10) were enrolled and eligible for analyses. They had similar baseline characteristics, tumor characteristics, clinical stage, and pathological stage. Conversion to thoracotomy was not observed, and the operation time {95 minutes [interquartile range (IQR), 86.5-136.5 minutes] vs. 86 minutes (IQR, 81-102 minutes), P=0.178} and other perioperative outcomes were comparable in the two groups. There was no significant difference in the number of dissected LNs and lymphatic stations between both groups. Conclusions: The application of Toumai® surgical robot in lobectomy was preliminarily shown to be safe and effective. Compared with the mature da Vinci robotic surgery system, Toumai® surgical robot had similar technical and surgical advantages, highlighting its suitability as an optional method for the new generation of robotic-assisted thoracoscopic surgery.

[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.

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.

Robotic single right anterior medial (S3b) subsegmentectomy for early primary lung cancer in a patient with a small physique.

Subsegmentectomy is an optional treatment for early primary lung cancer presenting without adequate surgical margins for wedge resection. There are no previous reports regarding a robotic single subsegmentectomy. We report a robotic single subsegmentectomy of the right anterior medial subsegment (S3b). The lung parenchyma was dissected with a Vessel Sealer Extend along the intersubsegmental veins for proper lung mobilization to solve the directional limitations of the robotic stapler. Additionally, we inserted the most ventral port from the subcostal region to increase the distance between the ports. Performing a robotic single subsegmentectomy is challenging. However, our techniques help to achieve a safe and effective operation.

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.

Interlobar division using vessel-sealing system in robot-assisted pulmonary lobectomy.

Objective: We investigated the safety of a novel interlobar fissure division technique using the da Vinci vessel sealing system in robot-assisted pulmonary lobectomy. Methods: The medical records of patients who underwent robotic pulmonary lobectomy with node dissection for primary lung cancer between 2018 and 2020 were reviewed. The inclusion criteria were fulfilled by 111 patients, whose perioperative factors and postoperative results were compared with those previously reported. Furthermore, the new robotic lung interlobar division technique using the da Vinci vessel sealing system without a robotic stapler was evaluated in patients with low-grade incomplete fissure. We considered the Craig and Walker classification of lung fissures grades 1 and 2 as a good adaptation for the vessel sealing system interlobar fissure division. Results: The vessel sealing system group had shorter mean operative and console times (P = .03 and P = .01, respectively) and lesser median intraoperative blood loss (20 mL vs 50 mL; P = .01). The vessel sealing system group had lower surgical complication rates (2.2% vs 20.0%; P = .01). The incidence of persistent postoperative air leak was lower (0% vs 10.0%; P = .06), and fewer robotic stapler cartridges were used during surgery (3.4 vs 5.6; P < .001) in the vessel sealing system group than in the stapler group. Conclusions: We report the safety of using the da Vinci vessel sealing system as an alternative to the use of robotic staples for interlobar fissure division in robot-assisted pulmonary lobectomy. This technique seems easy and feasible though limited to the low-grade incomplete fissure.

An aberrant medial basal segmental pulmonary artery (A7b) behind the superior segmental pulmonary vein (V6) in a patient undergoing right superior segment (S6) segmentectomy.

Herein, we report the first case of a patient with lung cancer with an aberrant medial basal segmental pulmonary artery (A7b) behind the superior segmental pulmonary vein (V6) who underwent right superior segment (S6) segmentectomy via uniportal video-assisted thoracoscopic surgery (uVATS). A 56-year-old man with a right lower lobe pure ground-glass nodule (GGN), measuring 12 mm in diameter on computed tomography (CT) had an aberrant A7b branching from the basal pulmonary artery, which was located behind the V6 as detected on 3D CT. The right S6 segmentectomy, via uVATS, for the GGN was performed. The postoperative course was uneventful. The final pathological diagnosis was invasive adenocarcinoma (p-T1bN0M0, stage IA2) with no evidence of disease recurrence at 3-month follow-up. Thoracic surgeons should be aware of the possibility of damaging the A7b when dividing the V6 for S6 segmentectomy, especially during uVATS because of insufficient dorsal visibility.

Pseudocirrhosis caused by lung adenocarcinoma with diffuse liver metastasis: An autopsy case report.

We describe a rare case of a 64-year-old man with lung adenocarcinoma with lymph node and bone metastases who developed pseudocirrhosis. Initial examination revealed a hepatic disorder of unknown cause with narrowing of the portal vein and a low-density area surrounding the portal veins in computed tomography (CT) imaging. Diffuse liver metastasis was diagnosed after percutaneous liver biopsy. During chemotherapy, liver atrophy and irregular liver surface appearance were confirmed with CT. Eventually, the disease progressed to death, and an autopsy was performed. The autopsy demonstrated exacerbation of diffuse liver metastases and cirrhosis-like findings.

Pulmonary arteriovenous malformation with metal allergy.

We present a rare case of single pulmonary arteriovenous malformation (PAVM) with multiple metal allergies, including for platinum. A 47-year-old woman presented to our hospital without any symptoms. Enhanced computed tomography showed a single PAVM in S6 of the right lung. Interviews prompted us to suspect a history of palmoplantar pustulosis associated with metal dental filling. Dermatology patch tests for metal allergy were positive for platinum, cobalt, tin and potassium dichromate. The first choice of treatment for PAVM is endovascular treatment using a metal coil. Since the coil is composed of platinum alloy, we performed partial lung resection for PAVM without metal implants. Although metal allergy is rare for endovascular treatment, it causes an additional stress of removal of causative metal or long-term steroidal treatment. Therefore, for single PAVM with multiple metal allergies to the implants, surgical treatment without metal implants should be considered.

An aberrant mediastinal medial basal segmental pulmonary artery (A7a) in a patient with lung cancer: a case report.

BACKGROUND: Mediastinal branching of the A7a from the right main pulmonary artery (PA) is extremely rare. Herein, we report a patient with an aberrant mediastinal A7a who underwent right basal segmentectomy for lung cancer. CASE PRESENTATION: A 73-year-old man was referred to our department for a right lower lobe nodule measuring 18 mm in diameter on computed tomography (CT). Three-dimensional (3D) CT revealed mediastinal A7a branching from the right main PA. As the patient had undergone colectomy for advanced ascending colon cancer, the nodule was suspected to be a metastasis from the colon primary, and thus, basal segmentectomy of the right lung was performed. Intraoperatively, the A7a was observed behind the V4+5 and middle lobe bronchus. The pathological diagnosis was combined small cell carcinoma with an adenocarcinoma component (p-T1cN0M0, stage IA3). The patient subsequently received adjuvant chemotherapy for colon cancer. At 1-year postoperative follow-up, there was no evidence of disease. CONCLUSION: This is the first report describing an aberrant mediastinal A7a branching from the right main PA. It is important to obtain accurate information about variations of the PA using 3D-CT for safe anatomical pulmonary resection.

Spontaneous pneumothorax in a patient with multiple pulmonary arteriovenous malformations caused by hereditary hemorrhagic telangiectasia: a case report.

Spontaneous pneumothorax occurring in patients with pulmonary arteriovenous malformations (PAVMs) caused by hereditary hemorrhagic telangiectasia (HHT) is extremely rare. We report a case of spontaneous pneumothorax in a PAVM patient. A 26-year-old man with previously diagnosed HHT and multiple small PAVMs presented with chest pain and dyspnea and was referred to our hospital. Chest X-ray showed a left-sided pneumothorax. Computed tomography (CT) showed apical bullae on both sides of the upper lobe. We clarified the location of PAVMs by 3D-CT to avoid the massive bleeding caused by careless grasping of PAVMs and unintentional incomplete resection of the PAVMs during the pneumothorax surgery. Considering the risk of exacerbation, the patient underwent bullectomy of the left upper lobe. The postoperative histopathological examination indicated that the pneumothorax occurred spontaneously in the HHT patient. We should clarify the location of PAVMs to avoid bleeding caused by the grasping of PAVMs during surgery.

Highly sensitive detection of a HER2 12-base pair duplicated insertion mutation in lung cancer using the Eprobe-PCR method.

Somatic mutation in human epidermal growth factor receptor-related 2 gene (HER2) is one of the driver mutations in lung cancer. HER2 mutations are found in about 2% of lung adenocarcinomas (ADCs). Previous reports have been based mainly on diagnostic screening by Sanger sequencing or next-generation sequencing (NGS); however, these methods are time-consuming and complicated. We developed a rapid, simple, sensitive mutation detection assay for detecting HER2 12 base pair-duplicated insertion mutation based on the Eprobe-mediated PCR method (Eprobe-PCR) and validated the sensitivity of this assay system for clinical diagnostics. We examined 635 tumor samples and analyzed HER2 mutations using the Eprobe-PCR method, NGS, and Sanger sequencing. In a serial dilution study, the Eprobe-PCR was able to detect mutant plasmid DNA when its concentration was reduced to 0.1% by mixing with wild-type DNA. We also confirmed amplification of the mutated plasmid DNA with only 10 copies per reaction. In ADCs, Eprobe-PCR detected the HER2 mutation in 2.02% (9/446), while Sanger sequencing detected it in 1.57% (7/446). Eprobe-PCR was able to detect the mutation in two samples that were undetectable by Sanger sequencing. All non-ADC samples were wild-type. There were no discrepancies between frozen and formalin-fixed paraffin-embedded tissues in the nine samples. HER2 mutations detected by NGS data validated the high sensitivity of the method. Therefore, this new technique can lead to precise molecular-targeted therapies.

Prognostic potential of the MDM2 309T>G polymorphism in stage I lung adenocarcinoma.

The MDM2 protein plays an important role in the regulation of cell proliferation and apoptosis via ubiquitination and proteasome-mediated degradation of p53. The genetic polymorphism rs2279744 (c.309T>G) of the MDM2 gene is reportedly associated with susceptibility and/or prognosis in various cancers. In this study, we investigated the risk factors for worse survival in patients with lung adenocarcinoma (AC). We examined the association between c.309T>G and the prognosis of lung cancer by retrospectively reviewing 453 lung cancer patients. We studied both, clinicopathological and genetic characteristics, including the c.309T>G, p53 Arg72Pro, EGFR, KRAS, and p53 mutations. Associations between these factors and survival outcome were analyzed using Cox proportional hazards models. The frequencies of MDM2 polymorphisms were T/T, 20.8%; T/G, 48.6%, and G/G, 30.7%. The overall survival (OS) of AC patients with pathological stage I disease and the MDM2 T/T genotype was significantly shorter than that of those with the T/G or G/G genotypes (P = 0.02). Multivariate analysis revealed that the MDM2 T/T genotype was an independent, significant prognostic factor (hazard ratio [HR] = 2.23; 95% confidence interval [CI]: 1.07-4.65; P = 0.03). The MDM2 T/T genotype was predictive of poorer survival in a Japanese population. Genotyping for this polymorphism might predict the clinical outcomes of stage I AC patients.