Feasibility and safety of uniport robotic-assisted thoracoscopic surgery in initial series of anatomical pulmonary resections under learning curve.

OBJECTIVES: Uniport robotic assisted thoracoscopic surgery (U-RATS) is a recently adopted approach in thoracic surgery and is assumed to require a learning curve for surgeons because of technical difficulties. We aimed to verify the feasibility and safety of solo surgery in U-RATS in an initial series of patients, comparing with initial series of uniport video-assisted thoracoscopic surgery (U-VATS). METHODS: The surgical and post-operative outcomes of 25 U-RATS cases were compared with 25 U-VATS cases. The da Vinci Xi Surgical System was used for U-RATS procedure. In both groups, the skin incisions were 4 cm in length, and a 30-degree camera was placed at the posterior and upper edges of the incision. RESULTS: Between June and December 2023, 25 patients with lung malignancies underwent anatomical pulmonary resection via U-RATS, including 13 lobectomies and 12 segmentectomies. Patient characteristics did not differ between the groups. The short-term outcomes were similar between the U-RATS and U-VATS groups, except for operation time (median: 214 vs. 157 min, p = 0.0035). The pain scores on postoperative days 1 and 3 were significantly lower in patients who underwent U-RATS than in those who underwent U-VATS (median: 0 vs. 2, p = 0.010; median: 0 vs. 0, p = 0.027, respectively). CONCLUSIONS: The short-term outcomes are similar between the U-RATS and U-VATS groups, except for operation time. U-RATS is considered to be feasible and safe in the initial series of anatomical pulmonary resections performed by a surgeon who was under the learning curve.

Accuracy of lung ultrasound examinations of residual congestion performed by novice residents in patients with acute heart failure.

AIMS: The popularity of B-line-guided congestion assessment by lung ultrasound (LUS) has been increasing. However, the ability of novice residents to detect residual congestion with B-line-guided assessment by LUS after decongestion treatment is poorly understood. In this study, we investigated whether novice residents (no prior echocardiography experience) can acquire the skills for B-line-guided residual congestion assessment and whether the range of variation in assessment is acceptable in actual clinical use. METHODS AND RESULTS: The study included 30 postgraduate first-year novice residents and an expert. The residents underwent training for LUS. At the end of the training session, a set of 15 LUS videos was provided to the residents, and they were asked to estimate the number of B-lines in each video. When the residents' answers greatly differed from the correct answer, we provided feedback to raise awareness of the discrepancies. After the training session, the residents performed residual congestion assessment by LUS after decongestion treatment in patients hospitalized with acute heart failure. The residents identified residual congestion in 57% of the patients. The sensitivity and specificity to identify residual congestion by the residents were 90% and 100%, respectively. The inter-operator agreement between the residents and the expert was substantial (κ = 0.86). The Spearman rank correlation coefficient for the B-lines between the expert and each resident was very high at 0.916 (P < 0.0001). CONCLUSIONS: After a brief lecture, novice residents can achieve proficiency in quantifying B-lines on LUS and can reliably identify residual congestion on LUS.

A retrospective analysis of treatment selection and risk factors of treatment failure and recurrence in patients with spontaneous pneumothorax.

Background: Conservative observation with/without oxygen supplementation, aspiration, or tube drainage is selected as an initial treatment for spontaneous pneumothorax. In this study, we examined the efficacy of initial management for cessation of air leak and prevention of recurrence, with consideration of the degree of lung collapse. Methods: Spontaneous pneumothorax in patients who underwent initial management in our institute between January 2006 and December 2015 were included in this retrospective, single-institutional study. Multivariate analyses were conducted to identify risk factors related to the treatment failure after initial treatment and those related to ipsilateral recurrence after last treatment. Results: Of 668 episodes of 522 patients, 198 events were initially treated by observation, 22 by aspiration, and 448 by tube drainage. Successive outcome for cessation of air leak in initial treatment was achieved in 170 (85.9%), 18 (81.8%), and 289 (64.5%) events, respectively. In the multivariate analysis for predicting failure after first treatment, previous episode of ipsilateral pneumothorax [odds ratio (OR) 1.9; 95% confidence interval (CI): 1.3-2.9; P<0.01], high degree of lung collapse (OR 2.1; 95% CI: 1.1-4.2; P=0.032), and bulla formation (OR 2.6; 95% CI: 1.7-4.1; P<0.0001) were the significant risk factors for treatment failure. Recurrence of ipsilateral pneumothorax was observed in 126 (18.9%) cases: 18 of 153 cases (11.8%) in the observation group, 3 of 18 cases in the aspiration group (16.7%), 67 of 262 cases in the tube drainage group (25.6%), 15 of 63 cases in the pleurodesis group (23.8%), and 23 of 170 cases in the surgery group (13.5%). In the multivariate analysis for predicting recurrence, previous episode of ipsilateral pneumothorax was a significant risk factor [hazard ratio (HR) 1.8; 95% CI: 1.2-2.5; P<0.001]. Conclusions: Predictive factors for failure after initial treatment were recurrence of ipsilateral pneumothorax, high degree of lung collapse, and radiological evidence of bullae. The predictive factor for recurrence after the last treatment was the previous episode of ipsilateral pneumothorax. Observation was superior to tube drainage in success rate to cease air leak and recurrence rate, although this effect was not statistically significant.

Stagnating blood flow related to thrombus formation in pulmonary vein stump after left upper lobectomy.

OBJECTIVES: A thrombus can occur in the stump of the pulmonary vein after left upper lobectomy, potentially causing postoperative cerebral infarction. This study aimed to verify the hypothesis that stagnation of blood flow inside the pulmonary vein stump causes thrombus formation. METHODS: The three-dimensional geometry of the pulmonary vein stump after left upper lobectomy was recreated using contrast-enhanced computed tomography. Blood flow velocity and wall shear stress (WSS) inside the pulmonary vein stump were analysed using the computational fluid dynamics (CFD) method and compared between the two groups (those with or without thrombus). RESULTS: The volumes of average flow velocity per heartbeat < 10 mm/s, 3 mm/s, 1 mm/s (p-values 0.0096, 0.0016, 0.0014, respectively) and the volumes where flow velocity was always below the three cut-off values (p-values 0.019, 0.015, 0.017, respectively) were significantly larger in patients with a thrombus than in those without thrombus. The areas of average WSS per heartbeat < 0.1 Pa, 0.03 Pa, 0.01 Pa (p-values 0.0002, < 0.0001, 0.0002, respectively), and the areas where WSS was always below the three cut-off values (p-values 0.0088, 0.0041, 0.0014, respectively) were significantly larger in patients with thrombus than in those without thrombus. CONCLUSIONS: The area of blood flow stagnation in the stump calculated by CFD method was significantly larger in patients with than in those without thrombus. This result elucidates that stagnation of blood flow promotes thrombus formation in the pulmonary vein stump in patients who undergo left upper lobectomy.

Successful endobronchial occlusion in empyema with broncho-pleural fistula secondary to COVID-19 pneumonia: a case report and literature review.

A few cases of empyema secondary to coronavirus disease 2019 (COVID-19) pneumonia have been reported. Here, we report our experience of a successful endobronchial occlusion using endobronchial Watanabe spigots (EWSs) for empyema with broncho-pleural fistula secondary to COVID-19 pneumonia. A 62-year-old man was diagnosed with COVID-19 and progressed to empyema with broncho-pleural fistula. Computed tomography (CT) imaging showed cyst formation and the right B5b was presumed to be a branch dependent on the cyst. The effusion and air in the pleural cavity were well drained, although the air leak persisted. Endobronchial occlusion was performed for right B5a and B5b using 7- and 5-mm EWSs (Novatech, France), respectively, and the air leak ceased. This is the first report of successful treatment of empyema with bronchial fistula with endobronchial occlusion. Air leak secondary to COVID-19 pneumonia with a limited number of air cysts may be a good indication for endobronchial occlusion.

The predictive value of preoperative risk assessments and frailty for surgical complications in lung cancer patients.

PURPOSE: To assess the predictive value of frailty and risk assessments for postoperative complications in lung cancer patients, we reviewed various risk indicators: including FEV1, ppoFEV1, the Zubrod performance status, the American Society of Anesthesiologist score, and risk models based on the Japan National Clinical Database (NCD) and the European Society of Thoracic Surgeons (ESTS) database. METHODS: Patients who underwent elective surgery between April 2016 and May 2019 were enrolled. A statistical analysis was performed to compare any differences among the risk indicators. RESULTS: The total number of patients enrolled was 193. Thirteen patients (6.7%) were classified as frail and 28 (14.5%) as pre-frail. Among the various risk indicators, the risk models based on the Japan NCD and the ESTS database revealed statistically significant differences in patients with and without postoperative complications (p value < 0.0001 and 0.0049, respectively), although there were no significant differences in frailty. The area under the receiver operating characteristic curve for risk models based on the Japan NCD registry and the ESTS registry was 0.70 and 0.64, respectively. CONCLUSIONS: Our analyses of a series of lung cancer patients showed that frailty was not a significant predictor of postoperative outcomes, while risk models based on academic society databases were found to have a significant predictive value.

Ligating the pulmonary vein at the pericardial reflection is useful for preventing thrombus formation in the pulmonary vein stump after left upper lobectomy.

OBJECTIVES: Thrombus formation in the pulmonary vein stump after left upper lobectomy is supposedly a risk factor for systemic thrombosis, resulting in a critical course for the patient. The purpose of this study was to assess the efficacy of the proximal ligation method preventing thrombus formation and thrombosis comparing the two groups of patients (those who did and those who did not undergo pulmonary vein ligation). METHODS: We performed a surgical procedure to shorten the pulmonary vein stump in the left upper lobectomy. In this procedure, we first dissected the pericardium from the left upper pulmonary vein, and then we ligated the pulmonary vein at the pericardial reflection before stapling transection. RESULTS: In the group that was not treated with the proximal ligation method, thrombus formation in the pulmonary vein stump was detected in all four cases. In contrast, thrombus formation in the pulmonary vein stump was detected in one only case of the eight cases treated with the proximal ligation method, which was significantly fewer than among those not treated with the ligation method (p = 0.010). The logistic regression analysis revealed in both the univariate (p = 0.0014) and multivariate analyses (p = 0.0071) that the proximal ligation method was significantly associated with reduced thrombus formation in the pulmonary vein stump. CONCLUSIONS: Thrombus formation in the pulmonary vein stump was significantly reduced by ligating the pulmonary vein at the pericardial reflection.

Measurement of intrapleural pressure in patients with spontaneous pneumothorax: a pilot study.

BACKGROUND: The initial management of pneumothorax remains controversial, and we speculated that this might be because there is no method available for evaluation of air leak during initial management. We have developed a system for measurement of intrapleural pressure in pneumothorax to address air leak without the need for chest drainage. The aim of this clinical study was to confirm the ability of this measurement system and to determine the clinical impact of management of air leak. METHODS: Patients in whom need aspiration was indicated for spontaneous pneumothorax were enrolled in the study. The intrapleural pressure was measured during stable breathing and data recorded when patients were coughing were excluded. RESULTS: Eleven patients were enrolled in the study between December 2016 to July 2017. The patterns in change of intrapleural pressure varied widely depending on the state of the pneumothorax. The mean intrapleural pressure values on end-inspiration and end-expiration in patients with persistent air leak was significantly lower than those in patients without persistent air leak (p = 0.020). The number of negative mean pressure recordings in end-inspiration and end-expiration was significantly lower in patients with persistent air leak than in those without persistent air leak (p = 0.0060). CONCLUSIONS: In this study, we demonstrated that intrapleural pressure could be successfully measured and visualized in patients with pneumothorax. Whether or not the pressure value is a predictor of persistent air leak needs to be confirmed in the future.

Clinical and pathological characteristics of spontaneous pneumothorax in women: a 25-year single-institutional experience.

OBJECTIVES: Accumulating evidence suggests that spontaneous pneumothorax (SP) in women, while relatively rare, has higher rates of post-treatment recurrence than in men. Our aim was to further elucidate the clinical and pathological characteristics of SP in women. METHODS: We retrospectively reviewed 59 female patients with no known underlying lung disease undergoing surgery for their SP from January 1990 to December 2015. We divided the study population into those older than or equal to 50 years and those younger than 50 years, the latter of which was further subdivided into catamenial and non-catamenial pneumothorax. RESULTS: Among the study population, 11 (18.6%) had catamenial pneumothorax, 40 (67.8%) had non-catamenial pneumothorax, and 8 (13.6%) were older than 50 years. Pathological diagnoses of catamenial pneumothorax were diaphragmatic endometriosis (n = 4), emphysematous bullae (n = 4), solitary pulmonary capillary hemangiomatosis (SPCH, n = 2), and hematoma (n = 1). By contrast, emphysematous blebs/bullae accounted for all but one case of non-catamenial pneumothorax and all cases in the ≥ 50 years age group. Catamenial pneumothorax showed a significantly higher postoperative recurrence rate compared to non-catamenial pneumothorax (p = 0.0043). The 2-year cumulative ipsilateral recurrence rates of catamenial, non-catamenial, and ≥ 50 years age group were 39.4, 13.8, and 14.3%, respectively. CONCLUSIONS: Catamenial pneumothorax affected approximately 20% of female patients undergoing surgery for spontaneous pneumothorax with no underlying lung disease and showed a significantly higher postoperative recurrence rate. Diaphragmatic endometriosis and subpleural blebs/bullae were common pathological findings in catamenial pneumothorax, but SPCH might be a possible pathological diagnosis of catamenial pneumothorax.

Recurrent cerebral attack caused by thrombosis in the pulmonary vein stump in a patient with left upper lobectomy on anticoagulant therapy: case report and literature review.

BACKGROUND: Thrombus formation in the pulmonary vein stump after pulmonary resection has recently been identified as a cause of systemic thrombosis including brain infarction. However, there is limited research focusing on the clinical course of pulmonary vein stump thrombus, and optimal treatment and prevention strategies of this important complication have not been established. CASE PRESENTATION: A 77-year-old woman was diagnosed with lung cancer of the left upper lobe, cT4N2M0, cStage IIIB. As the tumor was considered to be completely resectable, the patient underwent a left upper lobectomy with angioplasty of the left pulmonary artery. The final pathological stage was pT4N2M0, pStage IIIB. The patient developed paralysis of the right upper limb and dysarthria on the 8th postoperative day. Diffusion-weighted magnetic resonance imaging (MRI) of the brain showed multiple high-intensity signals in the area of the left middle cerebral artery, which were not detected on preoperative MRI. She was diagnosed with a cerebral infarction and started on acute-phase treatment including anticoagulation with continuous intravenous heparin infusion. The neurological symptoms improved the following day. Contrast-enhanced chest CT scan revealed thrombus in the left superior pulmonary vein stump measuring 10 mm in diameter. She had no comorbidity related to the cerebral attack. After the treatment was initiated, her symptoms became stable. However, symptoms of altered consciousness, dysarthria, and hemiparesis re-occurred on the 19th postoperative day and improved within an hour. The thrombus in the left superior pulmonary vein stump disappeared on follow-up contrast-enhanced chest CT performed the same day. CONCLUSIONS: This is the first report of recurrent brain attack caused by thrombosis in the pulmonary vein stump in a patient receiving anticoagulant therapy. The present case suggests the possibility of thrombus mobilization causing recurrent systemic thrombosis, and this important complication needs to be considered in future clinical practice.

Efficacy and long-term clinical outcome of bronchial occlusion with endobronchial Watanabe spigots for persistent air leaks.

BACKGROUND: We reviewed our clinical experience and examined the efficacy and long-term outcome of bronchial occlusion with endobronchial Watanabe spigots (EWSs). METHODS: We retrospectively reviewed the clinical charts of patients who had undergone endoscopic bronchial occlusion with EWSs between July 2002 and July 2004. The affected bronchi were identified by chest computed tomography, pleurography, and balloon occlusion test. RESULTS: Of the 21 patients, 18 had underlying pulmonary complications, including chronic obstructive lung disease (n=14), cancer (n=4), pneumoconiosis (n=3), and pneumonia (n=1). Six (29%) achieved complete resolution and 12 (57%) experienced a reduction in air leaks after the first EWS insertion. Of the 12 patients with reduced air leaks, 10 subsequently underwent chemical pleurodesis and 5 (24%) achieved complete resolution after the procedure. A second EWS insertion procedure was performed for 8 patients: 2 achieved complete resolution and 5 achieved a further reduction in air leaks with complete resolution after chemical pleurodesis. Eighteen of the 21 patients were followed up at an outpatient clinic after discharge: 13 for more than 12 months and 4 for more than 84 months. During the follow-up period, most patients did not show any obvious pulmonary complications. CONCLUSIONS: We showed that bronchial occlusion with EWSs was effective in stopping or reducing air leaks and that 86% of our patients finally achieved complete resolution, some when the occlusion was combined with chemical pleurodesis. The rate of complications was acceptable, even after long-term placement.

A decrease in the size of ground glass nodules may indicate the optimal timing for curative surgery.

OBJECTIVES: Although ground glass nodules (GGNs) are generally considered to grow slowly to a large size, their natural progression remains unclear, and a decrease in tumor size has been reported in a few previous studies. The study aimed to retrospectively review the radiologic and pathological characteristics of resected ground glass nodules (GGNs) followed with chest computed tomography (CT) for at least a year before surgery to clarify the natural progression of GGNs. PATIENTS AND METHODS: The chest CT cans and clinical charts of 32 GGNs in 31 patients who underwent pulmonary resection between January 2006 and March 2013 were retrospectively reviewed. The definitions of pure GGNs and part-solid nodules were based on the tumor shadow disappearance rate. The tumor size was measured twice, and the mean size was used for evaluation. RESULTS: The mean GGN size before surgery was 15.2 mm, and the median follow-up period before surgery was 21 months. In the follow-up period, 15 (58%) of 26 pure GGNs at the initial CT remained pure GGNs at the last CT. However, a solid component appeared in the remaining 11 tumors (42%) of the 26 initial pure GGNs. Furthermore, 1 GGN of the 15 GGNs that remained pure and 10 of the 11 GGNs with solid component also showed a size decrease. In addition, 6 part-solid nodules were observed at the initial CT. Of these, 3 showed a decrease in size during follow-up. Overall, 47% of the GGNs showed a size reduction on follow-up chest CT. CONCLUSIONS: A size reduction was observed in nearly half of the GGNs and suggested the progression to an invasive adenocarcinoma. When a mild collapse of the GGNs is observed, a careful follow-up is necessary to identify a solid component. Tumor size decreases may represent the optimal timing of pulmonary resection for curative treatment.

Three-step management of pneumothorax: time for a re-think on initial management.

Pneumothorax is a common disease worldwide, but surprisingly, its initial management remains controversial. There are some published guidelines for the management of spontaneous pneumothorax. However, they differ in some respects, particularly in initial management. In published trials, the objective of treatment has not been clarified and it is not possible to compare the treatment strategies between different trials because of inappropriate evaluations of the air leak. Therefore, there is a need to outline the optimal management strategy for pneumothorax. In this report, we systematically review published randomized controlled trials of the different treatments of primary spontaneous pneumothorax, point out controversial issues and finally propose a three-step strategy for the management of pneumothorax. There are three important characteristics of pneumothorax: potentially lethal respiratory dysfunction; air leak, which is the obvious cause of the disease; frequent recurrence. These three characteristics correspond to the three steps. The central idea of the strategy is that the lung should not be expanded rapidly, unless absolutely necessary. The primary objective of both simple aspiration and chest drainage should be the recovery of acute respiratory dysfunction or the avoidance of respiratory dysfunction and subsequent complications. We believe that this management strategy is simple and clinically relevant and not dependent on the classification of pneumothorax.

Lesions in patients with multifocal adenocarcinoma are more frequently in the right upper lobes.

OBJECTIVES: Opportunities to treat multifocal lung cancers, mostly adenocarcinoma, are increasing due to the development of imaging technologies. The optimal therapy modality to treat multifocally growing lung cancers remains obscure. To determine the features of multifocal lung cancers, we retrospectively reviewed patients with multiple lung lesions. METHODS: Clinical, pathological and genetic characteristics of 31 patients with multifocal lesions were compared with those of patients who had had radical lung resection for solitary lung cancer. Gene mutation analyses for EGFR, KRAS and P53 were performed on three tumours of each of the patients who had four or more lesions. RESULTS: Of the 31 patients, 17 had double tumours, 4 had triple tumours and 10 had 4 or more lesions. Patients with four or more lesions were significantly more likely to be females and never smokers. All of the histologically confirmed tumours of the cases with four or more lesions were adenocarcinoma in situ or lepidic predominant adenocarcinoma. The number of lesions in the right upper lobes when compared with the right lower lobes was significantly higher in patients with four or more lesions than in patients with double or triple lesions (P = 0.013). Five of the 12 tumours were positive for the EGFR mutation L858R in exon 21. No KRAS mutation was found. CONCLUSIONS: Lesions in patients with multifocal adenocarcinoma are more frequently in the right upper lobes. Genetic analysis suggested that the specific EGFR mutation L858R in exon 21 might be the main factor contributing to lung carcinogenesis in multiple lung cancers. Further investigation of the right upper lobe in those patients compared with the lower lobes might provide more insights into lung carcinogenesis.

Impact of previous gastrectomy on postoperative pneumonia after pulmonary resection in lung cancer patients.

Postoperative pneumonia is a serious complication following pulmonary resection. Aspiration of oesophageal reflux contents is known to cause pulmonary complications in patients with a history of gastrectomy. In this study, we compared the incidence of postoperative pneumonia in patients with or without previous gastrectomy. A retrospective review was conducted of clinical charts for patients who underwent radical pulmonary resection for non-small cell lung cancer from January 2006 to December 2010. Pneumonia was diagnosed with chest computed tomography findings in all cases. A total of 333 patients underwent pulmonary resections during the study period. Twenty-seven patients (8.1%) had a history of gastrectomy. Eight patients (2.2%) had postoperative pneumonia. All eight patients who developed postoperative pneumonia did not have pneumonia before pulmonary resection. Of the aforementioned 27 patients, five (18.5%) developed pneumonia postoperatively, whereas only three of 325 patients who did not have a history of gastrectomy (0.9%) had pneumonia (P < 0.001). In multivariate analysis, a history of gastrectomy had the highest impact on the odds ratio (8.81) for postoperative pneumonia. A significantly higher incidence of postoperative pneumonia was found in patients with a history of gastrectomy. Prophylactic treatment, such as premedication with ranitidine, should be considered in those patients.

Primary squamous cell carcinoma in the gastric remnant.

A 67-year-old male developed primary gastric squamous cell carcinoma (SCC) 13 years after undergoing distal gastrectomy for gastric cancer. Gastroscopy revealed a type 2 gastric remnant tumor and tumor biopsies revealed poorly differentiated carcinoma. The patient underwent remnant gastrectomy with lateral segment hepatectomy, splenectomy, partial resection of diaphragm, and distal partial esophagectomy. The histological findings revealed SCC without an adenocarcinoma component in the gastric remnant tumor. The patient died 13 months after surgery due to multiple-organ metastasis of gastric SCC. The post-operative prognosis of gastric SCC cases tends to poorer than that of gastric adenocarcinoma. Early diagnosis is important to improve the prognosis of primary gastric SCC and pathogenetic analysis of gastric SCC may contribute to improving the diagnosis and treatment of carcinogenesis and the prognosis of gastric SCC.