Serial improvement of quality metrics in pediatric thoracoscopic lobectomy for congenital lung malformation: an analysis of learning curve.

BACKGROUND: Video-assisted thoracic surgery (VATS) pulmonary resection in children is a technically demanding procedure that requires a relatively long learning period. This study aimed to evaluate the serial improvement of quality metrics according to case volume experience in pediatric VATS pulmonary resection of congenital lung malformation (CLM). Methods VATS anatomical resection in CLM was attempted in 200 consecutive patients. The learning curve for the operative time was modeled by cumulative sum analysis. Quality metrics were used to measure technical achievement and efficiency outcomes. Results The median operative time was 95 min. The median length of hospital stay and chest tube indwelling time was 4 and 2 days, respectively. The improvement of operation time was observed persistently until 200 cases. However, two cut-off points, the 50th case and 110th case, were identified in the learning curve for operative time, and the 110th case was the turning point for stable outcomes with short operation time. Significant reduction of length of hospital stay and chest tube indwelling time was observed after 50 cases (p = .002 and p = .021, respectively). The complication rate decreased but continued at a low rate for entire study period and the interval decrease was not statistically significant. Conversion rate decreased significantly (p = .001), and technically challenging procedures were performed more frequently in later cases. Conclusions Improvements of quality metrics in operation time, conversion rate, length of hospital stay, and chest tube indwelling time were observed in proportion to case volume. Minimum experience of 50 is necessary for stable outcomes of pediatric VATS pulmonary resection.

Porcine endothelium induces DNA-histone complex formation in human whole blood: a harmful effect of histone on coagulation and endothelial activation.

BACKGROUND: Neutrophils play a role in xenograft rejection. When neutrophils are stimulated, they eject the DNA-histone complex into the extracellular space, called neutrophil extracellular traps (NET). We investigated whether NET formation actively occurs in the xenograft and contributes to coagulation and endothelial activation. METHODS: Human whole blood was incubated with porcine aortic endothelial cells (pEC) from wild-type or α1,3-galactosyltransferase gene-knockout (GTKO) pigs. In the supernatant plasma from human blood, the level of the DNA-histone complex was measured by ELISA, and thrombin generation was measured using a calibrated automated thrombogram. Histone-induced tissue factor and adhesion molecule expression were measured by flow cytometry. RESULTS: pEC from both wild-type and GTKO pigs significantly induced DNA-histone complex formation in human whole blood. The DNA-histone complex produced shortened the thrombin generation time and clotting time. Histone alone dose-dependently induced tissue factor and adhesion molecule expression in pEC. Aurintricarboxylic acid pretreatment partially inhibited pEC-induced DNA-histone complex formation. CONCLUSIONS: DNA-histone complex actively generated upon xenotransplantation is a novel target to inhibit coagulation and endothelial activation. To prevent tissue factor and adhesion molecule expression, a strategy to block soluble histone may be required in xenotransplantation.

Beneficial effect of a nitric oxide donor in an ex vivo model of pig-to-human pulmonary xenotransplantation.

BACKGROUND: Nitric oxide (NO) can reduce platelet adhesion and vascular resistance. Tempol can scavenge the reactive oxygen species (ROS) that induce tissue injury. As xenograft rejection attenuates endogenous NO production and generates ROS, we evaluated the potential effect of an NO donor (SIN-1, 3-morpholinosydnonimine) and tempol on hyperacute xenograft dysfunction using an ex vivo porcine lung perfusion model. METHODS: For the evaluation of von Willebrand factor (vWF) secretion, human endothelial cells were stimulated with thrombin. Porcine lungs were perfused with either fresh human whole blood (unmodified control group [n = 4]), SIN-1 (n = 4), or SIN and tempol (n = 4). RESULTS: SIN-1 and tempol significantly inhibited vWF secretion from endothelial cells in vitro. However, they did not suppress xenogeneic complement activation. In an ex vivo pulmonary perfusion model, SIN-1 improved pulmonary xenograft function by reducing pulmonary vascular resistance (PVR), inhibiting complement activation, and inhibiting thrombin generation. Combined treatment with tempol and SIN-1 potentiated PVR reduction, but slightly enhanced complement activation. CONCLUSIONS: An NO donor is expected to improve pulmonary xenograft function through inhibition of vWF secretion, vasoconstriction, thrombin generation, and indirectly through inhibition of complement activation. The additional effects of tempol on an NO donor were not considered significant in an ex vivo xenograft system.

The Optimal Treatment Strategy for Postoperative Anastomotic Leakage After Esophagectomy: a Comparative Analysis Between Endoscopic Vacuum Therapy and Conventional Treatment.

BACKGROUND: We compared the clinical outcomes between endoscopic vacuum therapy (EVT) and conventional treatment (CT) for the management of post-esophagectomy anastomotic leakage. METHODS: A retrospective review of the medical records of patients who underwent esophagectomy with esophagogastrostomy from November 2003 to August 2021 was conducted. Thirty-four patients who developed anastomotic leakage were analyzed according to whether they underwent CT (n = 13) or EVT (n = 21). RESULTS: The median time to complete healing was significantly shorter in the EVT group than in the CT group (16 [4-142] days vs. 70 [8-604] days; p = 0.011). The rate of clinical success was higher in the EVT group (90.5%) than in the CT group (66.7%, p = 0.159). A subgroup analysis showed more favorable outcomes for EVT in patients with thoracic leakage, including a higher clinical success rate (p = 0.037), more rapid complete healing (p = 0.004), and shorter hospital stays (p = 0.006). However, the results were not significantly different in patients with cervical leakage. Anastomotic strictures occurred in 3 EVT patients (14.3%) and 5 CT patients (50.0%) (p = 0.044), and the EVT group showed a trend towards improved freedom from anastomotic strictures (p = 0.105). CONCLUSIONS: EVT could be considered as an adequate treatment option for post-esophagectomy anastomotic leakage. EVT might have better clinical outcomes compared to CT for managing anastomotic leakage after transthoracic esophagogastrostomy, and further studies are needed to evaluate the effectiveness of EVT in patients who undergo cervical esophagogastrostomy.

Prognostic significance of tumor spread through air spaces in patients with stage IA part-solid lung adenocarcinoma after sublobar resection.

OBJECTIVES: The purpose of this study was to assess the clinicopathologic implications of tumor spread through air spaces (STAS) in patients with stage IA part-solid lung adenocarcinoma after sublobar resection. MATERIALS AND METHODS: Medical records of patients with stage IA part-solid adenocarcinoma who underwent curative pulmonary resection between February 2009 and December 2016 were retrospectively reviewed. The clinicopathological features of STAS and its influence on postoperative recurrence and survival were investigated. RESULTS: Among the 115 patients with stage IA part-solid adenocarcinoma who underwent wedge resection, 20 (17.4 %) had STAS. The multivariable analysis showed presence of STAS [HR (hazard ratio), 9.447; p = 0.002) and a larger invasive component size (HR, 1.097; p = 0.034) were independent risk factors for recurrence. The 5-year freedom from recurrence rates were 62.4 % and 97.9 % in cases with and without STAS, respectively (p < 0.001), and the 5-year disease-free survival rates were 58.5 % and 97.9 % in cases with and without STAS, respectively (p < 0.001). The presence of STAS was associated with old age (p = 0.030), male gender (p = 0.023), acinar predominant histologic pattern (p = 0.004), presence of micropapillary pattern (p < 0.001), lymphovascular invasion (p < 0.001) and larger invasive component (p < 0.001). CONCLUSION: STAS could be an important prognostic factor in patients with stage IA part-solid lung adenocarcinoma after sublobar resection. Effective preoperative evaluation and postoperative surveillance may help improve the outcome of patients with small part-solid nodules, particularly when accompanied by STAS.

Prognostic Significance of the Extranodal Extension of Regional Lymph Nodes in Stage III-N2 Non-Small-Cell Lung Cancer after Curative Resection.

The present study investigated the prognostic role of extranodal extension (ENE) in stage III-N2 non-small-cell lung cancer (NSCLC) following curative surgery. From January 2005 to December 2018, pathologic stage III-N2 disease was diagnosed in 371 patients, all of whom underwent anatomic pulmonary resection accompanied by mediastinal lymph node dissection. This study included 282 patients, after excluding 89 patients who received preoperative chemotherapy or incomplete surgical resection. Their lymph nodes were processed; after hematoxylin and eosin staining, histopathologic slides of the metastatic nodes were reviewed by a designated pathologist. Predictors of disease free survival (DFS), including age, sex, operation type, pathologic T stage, nodal status, visceral pleural invasion, perioperative treatment, and the presence of ENE, were investigated. Among the 282 patients, ENE was detected in 85 patients (30.1%). ENE presence was associated with advanced T stage (p = 0.034), N2 subgroups (p < 0.001), lymphatic invasion (p = 0.001), and pneumonectomy (p = 0.002). The multivariable analysis demonstrated that old age (p < 0.001), advanced T stage (p = 0.012), N2 subgroups (p = 0.005), and ENE presence (p = 0.005) were significant independent predictors of DFS. The DFS rate at five years was 21.4% in patients who had ENE and 43.4% in patients who did not have ENE (p < 0.001). The presence of ENE, coupled with tumor-node-metastasis staging, should be recognized as a meaningful prognostic factor in stage III-N2 NSCLC patients.

Predictive Factors for Lymph Node Metastasis in Clinical Stage I Part-Solid Lung Adenocarcinoma.

BACKGROUND: Accurate clinical staging of tumors with a small solid portion is essential for developing an appropriate treatment plan. This study evaluated predictive factors for lymph node (LN) metastasis in patients with clinical stage I part-solid lung adenocarcinoma. METHODS: Medical records of patients with clinical stage I part-solid adenocarcinoma who underwent anatomic pulmonary resection with systematic node evaluation between January 2009 and June 2018 were retrospectively reviewed. To identify predictive factors for LN metastasis, univariate and multivariable logistic regression analyses were performed. RESULTS: Among the 593 patients in this study, the overall prevalence of LN metastasis was 3.7% (n = 22), which included 3.0% (n = 18) of patients with N1 LN metastasis and 1.5% (n = 9) of patients with N2 LN metastasis. Combined N1 and N2 nodal involvement was observed in 5 patients. Nodal metastasis was not observed in tumors with a solid portion sized 1.1 cm or smaller. The nodal metastasis rates in cT1b, cT1c, and cT2a tumors were 5.5% (13 of 237), 7.1% (6 of 84), and 13.6% (3 of 22), respectively. According to the multivariable analysis, predictive factors included the size of the solid portion (P = .015) and the high maximum standardized uptake value (SUVmax) of the primary tumor (P = .044). CONCLUSIONS: Large solid portion and high SUVmax of the primary tumor were predictive factors of LN metastasis in patients with clinical stage I part-solid lung adenocarcinoma. Systematic LN evaluation should be performed, especially in those who have a large solid portion and high SUVmax of the primary tumor.

A newly developed capture-based sequencing panel for genomic assay of lung cancer.

BACKGROUND: The increase in genetic alterations targeted by specific chemotherapy in lung cancer has led to the need for universal use of more comprehensive genetic testing, which has highlighted the development of a lung cancer diagnostic panel using next-generation sequencing. OBJECTIVE: We developed a hybridization capture-based massively parallel sequencing assay named Friendly, Integrated, Research-based, Smart and Trustworthy (FIRST)-lung cancer panel (LCP), and evaluated its performance. METHODS: FIRST-LCP comprises 64 lung cancer-related genes to test for various kinds of genetic alterations including single nucleotide variations (SNVs), insertions and deletions (indels), copy number variations (CNVs), and structural variations. To assess the performance of FIRST-LCP, we compiled test sets using HapMap samples or tumor cell lines with disclosed genetic information, and also tested our clinical lung cancer samples whose genetic alterations were known by conventional methods. RESULTS: FIRST-LCP accomplished high sensitivity (99.4%) and specificity (100%) of the detection of SNVs. High precision was also achieved, with intra- or inter-run concordance rate of 0.99, respectively. FIRST-LCP detected indels and CNVs close to the expected allele frequency and magnitude, respectively. Tests with samples from lung cancer patients also identified all SNVs, indels and fusions. CONCLUSION: Based on the current state of the art, continuous application of the panel design and analysis pipeline following up-to-date knowledge could ensure precision medicine for lung cancer patients.

The role of postoperative radiotherapy in stage II and III thymoma: a Korean multicenter database study.

BACKGROUND: Complete resection is a standard treatment for patients with Masaoka-Koga stages II and III thymoma, however the role of postoperative radiotherapy (PORT) is controversial. We analyzed data collected from 4 Korean hospitals to determine the effectiveness of PORT in stage II and III thymoma patients. METHODS: Between January 2000 and December 2013, 1,663 patients underwent surgery for thymic tumors at the 4 hospitals. Among them, 668 patients (527 with stage II and 141 with stage III) were investigated, among whom, 443 received PORT (335 with stage II and 108 with stage III). Propensity score matching (PSM) was performed, and 404 patients (346 with stage II and 58 with stage III) were selected. RESULTS: Perioperative characteristics were similar in the PORT and non-PORT groups after PSM. On survival analysis of stage II patients, the PORT and non-PORT groups showed no difference in either 5-year recurrence-free survival (RFS) (96.3% vs. 96.6%, P=0.622) or 5-year overall survival (OS) (94.6% vs. 93.8%, P=0.839). However, among stage III patients, the PORT group showed significantly better 5-year RFS (75.7% vs. 50.1%, P=0.040) and 5-year OS (86.5% vs. 54.7%, P=0.001). On multivariate Cox regression analysis, PORT was a significant positive prognostic factor in terms of both RFS (P=0.005) and OS (P=0.004) in patients with stage III thymomas, but not in those with stage II disease (P=0.987 and 0.968, respectively). CONCLUSIONS: PORT improved the RFS and OS in stage III thymoma patients, but showed no survival benefit in stage II patients.

[Influence of Insurance Status on Survival of Surgically Treated Esophageal Cancer Patients].

BACKGROUND/AIMS: Socioecomomic factor is an important determinant of access to healthcare and is one of the potential causes of disparities in esophageal cancer care outcomes. The aim of the study was to clarify the association between National health Insurance status (health insurance vs. medicare) as a socioeconomic factor and survival of patients with esophageal cancer who underwent surgical resection. METHODS: Among the 66 patients who underwent surgical resection for esophageal cancer between January 2006 and December 2017, 17 patients (25.8%) were in the medicare group. The data were analyzed to identify clinical manifestations and to compare surgical and oncologic outcomes between the groups. RESULTS: There was no significant difference in the distribution of sex (p=0.13), age (p=0.24), and pathologic stage (p=0.61) between the groups. The length of median hospital stay was significantly shorter in the healthy insurance group (18 days vs. 25 days, p=0.04). In the medicare group, postoperative mortality rates and incidence of postoperative complication were non-significantly higher(11.8% vs. 6.1%, p=0.45, 64.7% vs. 46.7%, p=0.21, respectively). However, pulmonary complication rates, including pneumonia, acute respiratory distress syndorme, and prolonged air leakage was significantly higher in the medicare group (47.1% vs. 18.4%, p=0.02). Five-year disease free survival rate was not different between the two groups (61.0% vs. 54.5%, p=0.68); the 5-year overall survival rate was significantly lower in the medicare group (27.7% vs. 53.7%, p=0.03). CONCLUSIONS: The medicare status of National health insurance could have a negative influence on the overall survival in patients with esophageal cancer who underwent surgery.

Impact of Lymph Node Dissection on Thymic Malignancies: Multi-Institutional Propensity Score Matched Analysis.

INTRODUCTION: Surgical resection is a standard treatment for thymic malignancies. However, prognostic significance of nodal metastases and lymph node dissection remains unclear. The aim of this study is to determine prognostic significance of nodal metastases and the role of lymph node dissection (LND) in thymic malignancies. METHODS: Between 2000 and 2013, 1597 patients who underwent thymectomy due to thymic malignancy were included. Predictive factors for nodal metastasis and prognostic significance of LND were evaluated. Patients were divided into two groups: (1) LND+ group, with intentional LND (446 patients, 27.9%); and (2) LND- group, without intentional LND (1151 patients, 72.1%). Propensity score matching was performed between the two groups. RESULTS: Lymph node metastasis was identified in 20 (6.7%) of 298 patients with thymoma and 47 (31.7%) of 148 patients with thymic carcinoma. In multivariable analysis, thymic carcinoma (hazard ratio: 19.2, p < 0.001) and tumor size (hazard ratio: 1.09, p = 0.02) were significant predictive factors for lymph node metastasis. The 10-year freedom from recurrence rate of pN1 and pN2 was significantly worse than that of pN0 (p < 0.001). LND did not increase operative mortality or complication. There was no significant difference in 10-year freedom from recurrence rate between LND+ and LND- groups (82.4% versus 80.9%, p = 0.46 in thymoma; 45.7% versus 44.0%, p = 0.42 in thymic carcinoma). CONCLUSIONS: Lymph node metastasis was a significant prognostic factor in thymic malignancies. Although LND did not improve long-term outcomes in thymic malignancies, LND played a role in accurate staging, and improved prediction of prognosis.

Patterns and Prognostic Significance of Cervical Lymph Node Metastasis and the Efficacy of Cervical Node Dissection in Esophageal Cancer.

BACKGROUND: The clinical value of 3-field lymph node dissection (3FLND) in esophageal squamous cell carcinoma (ESCC) remains controversial. This study aimed to identify the patterns and prognostic significance of cervical lymph node metastasis (CLNM) in ESCC. METHODS: A retrospective review of 77 patients with ESCC who underwent esophagectomy and 3FLND between 2002 and 2016 was conducted. For each cervical node level, the efficacy index (EI), overall survival, recurrence rate, and complication rate were compared. RESULTS: CLNM was identified in 34 patients (44.2%) who underwent 3FLND. Patients with CLNM had a significantly lower overall survival rate (22.7% vs. 58.2%) and a higher recurrence rate (45.9% vs. 16.3%) than patients without CLNM. CLNM was an independent predictor of recurrence in ESCC patients. Moreover, in patients with pathologic N3 tumors, the odds ratio of CLNM was 10.8 (95% confidence interval, 2.0 to 57.5; p= 0.005). Level IV dissection had the highest EI, and level IV metastasis was significantly correlated with overall survival (p=0.012) and recurrence (p=0.001). CONCLUSION: CLNM was a significant prognostic factor for ESCC patients and was more common among patients with advanced nodal stages. Level IV exhibited the highest risk of metastasis, and dissection at level IV may be crucial when performing 3FLND, especially in advanced nodal stage disease.

Successful Lung Transplantation in a Patient with Myasthenia Gravis.

A 47-year-old man with myasthenia gravis (MG) was admitted for a lung transplant. He had bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation due to acute myeloid leukemia. MG developed after stem cell transplantation. Bilateral sequential lung transplantations and a total thymectomy were performed. The patient underwent right diaphragmatic plication simultaneously due to preoperatively diagnosed right diaphragmatic paralysis. A tracheostomy was performed and bilevel positive airway pressure (BiPAP) was applied on postoperative days 8 and 9, respectively. The patient was transferred to the general ward on postoperative day 12, successfully weaned off BiPAP on postoperative day 18, and finally discharged on postoperative day 62.

Current Trends of Lung Cancer Surgery and Demographic and Social Factors Related to Changes in the Trends of Lung Cancer Surgery: An Analysis of the National Database from 2010 to 2014.

PURPOSE: We investigated current trends in lung cancer surgery and identified demographic and social factors related to changes in these trends. MATERIALS AND METHODS: We estimated the incidence of lung cancer surgery using a procedure code-based approach provided by the Health Insurance Review and Assessment Service (http://opendata.hira.or.kr). The population data were obtained every year from 2010 to 2014 from the Korean Statistical Information Service (http://kosis.kr/). The annual percent change (APC) and statistical significance were calculated using the Joinpoint software. RESULTS: From January 2010 to December 2014, 25,687 patients underwent 25,921 lung cancer surgeries, which increased by 45.1% from 2010 to 2014. The crude incidence rate of lung cancer surgery in each year increased significantly (APC, 9.5; p < 0.05). The male-to-female ratio decreased from 2.1 to 1.6 (APC, -6.3; p < 0.05). The incidence increased in the age group of ≥ 70 years for both sexes (male: APC, 3.7; p < 0.05; female: APC, 5.96; p < 0.05). Furthermore, the proportion of female patients aged ≥ 65 years increased (APC, 7.2; p < 0.05), while that of male patients aged < 65 years decreased (APC, -3.9; p < 0.05). The proportions of segmentectomies (APC, 17.8; p < 0.05) and lobectomies (APC, 7.5; p < 0.05) increased, while the proportion of pneumonectomies decreased (APC, -6.3; p < 0.05). Finally, the proportion of patients undergoing surgery in Seoul increased (APC, 1.1; p < 0.05), while the proportion in other areas decreased (APC, -1.5; p < 0.05). CONCLUSION: An increase in the use of lung cancer surgery in elderly patients and female patients, and a decrease in the proportion of patients requiring extensive pulmonary resection were identified. Furthermore, centralization of lung cancer surgery was noted.

Risk Factors for Local Recurrence and Optimal Length of Esophagectomy in Esophageal Squamous Cell Carcinoma.

BACKGROUND: The risk factors for local recurrence in residual esophagus after esophagectomy have not been well documented. This study aimed to identify risk factors of local recurrence and optimal length of esophageal resection in esophageal cancer. METHODS: Patients who underwent curative esophagectomy with more than 2 years of follow-up were included. Patients who received preoperative chemoradiation or in whom the ex vivo length of proximal margin (LPM) from resected tumor was not documented in the pathologic report were excluded. A total of 551 patients from January 1995 to February 2013 were included. RESULTS: Complete resection was possible in 516 patients (94%), and mean LPM was 3.4 ± 2.5 cm. Sex, age, location of tumor, location of anastomosis, minimally invasive esophagectomy, three-field lymphadenectomy, cell type, differentiation, proximal resection margin status, tumor size, number of dissected lymph nodes, and T stages were not risk factors for local recurrence in multivariate analysis. The N stage (p = 0.034) and LPM (p = 0.007) were risk factors for local recurrence in multivariate analysis. The LPM was not related to local recurrence in N0, but 5-year freedom from local recurrence was higher for LPM of 5 cm or greater in N+ esophageal cancer (72% in LPM less than 5 cm versus 93% in LPM of 5 cm or greater, p = 0.040). CONCLUSIONS: Local recurrence after esophagectomy in esophageal cancer is related to lymphatic metastasis rather than to proximal margin status, which raises the possibility that the main mechanism of local recurrence is submucosal lymphatic metastasis. Esophagectomy with LPM more than 5 cm is recommended for esophageal cancer with nodal metastasis.

Comparison of robot-assisted esophagectomy and thoracoscopic esophagectomy in esophageal squamous cell carcinoma.

BACKGROUND: The aim of the study was to compare robot-assisted esophagectomy (RE) with thoracoscopic esophagectomy (TE) for the treatment of esophageal squamous cell carcinoma (ESCC). METHODS: A total of 105 patients who underwent RE (n=62) or TE (n=43) due to ESCC were included in this study. Early postoperative outcomes and long-term survivals between the two groups were compared. RESULTS: The RE and TE groups were comparable in preoperative clinical characteristics. Total operation times were not significantly different between the two groups (490 minutes in RE vs. 458 minutes in TE; P=0.118). The total number of dissected lymph nodes was significantly greater in the RE group (37.3±17.1 vs. 28.7±11.8; P=0.003), and intergroup differences were significant for numbers of lymph nodes dissected from the upper mediastinum (10.7±9.7 in RE vs. 6.3±9.3 in TE; P=0.032) and the abdomen (12.2±8.7 in RE vs. 7.8±7.1 in TE; P=0.007). Five-year overall survival was not different between the two groups (69% in RE and 59% in TE; P=0.737). CONCLUSIONS: Better quality lymphadenectomy could be achieved in RE although survival benefit was not clear. Prospective randomized studies comparing the RE and TE are necessary.

Surgical Management of Aorto-Esophageal Fistula as a Late Complication after Graft Replacement for Acute Aortic Dissection.

A 49-year-old male presented with chills and a fever. Five years previously, he underwent ascending aorta and aortic arch replacement using the elephant trunk technique for DeBakey type 1 aortic dissection. The preoperative evaluation found an esophago-paraprosthetic fistula between the prosthetic graft and the esophagus. Multiple-stage surgery was performed with appropriate antibiotic and antifungal management. First, we performed esophageal exclusion and drainage of the perigraft abscess. Second, we removed the previous graft, debrided the abscess, and performed an in situ re-replacement of the ascending aorta, aortic arch, and proximal descending thoracic aorta, with separate replacement of the innominate artery, left common carotid artery, and extra-anatomical bypass of the left subclavian artery. Finally, staged esophageal reconstruction was performed via transthoracic anastomosis. The patient's postoperative course was unremarkable and the patient has done well without dietary problems or recurrent infections over one and a half years of follow-up.

Robotic Thymectomy in Anterior Mediastinal Mass: Propensity Score Matching Study With Transsternal Thymectomy.

BACKGROUND: Robot-assisted thymectomy (RT) has been increasingly performed for treating anterior mediastinal masses. The aim of this study was to compare the early and long-term outcomes between RT and transsternal thymectomy (ST). METHODS: A total of 429 patients who underwent surgical resection of anterior mediastinal masses were included in this study. RT was performed in 117 patients (27%). Propensity score matching was performed between RT and ST, and 100 patients were selected for each group. RESULTS: RT and ST were performed for anterior mediastinal masses, including thymic epithelial tumor and mediastinal cysts. Thymic epithelial tumor was the most common type of tumor, and distribution of pathologic stages was not significantly different between RT and ST (41% versus 39% in stage I, 46% versus 50% in stage II, 9% versus 5% in stage III, and 4% versus 5% in stage IV, p = 0.96). The RT group had significantly less intraoperative blood loss (100.9 ± 105.4 mL versus 354.5 ± 412.4 mL, p < 0.001), lower incidence of postoperative complication (1% versus 12%, p = 0.002), and shorter length of postoperative hospital stay (2.5 ± 1.2 days versus 6.4 ± 6.6 days, p < 0.001) compared with the ST group. Three-year overall survival rates and freedom from recurrence were not significantly different (100% versus 100%; p = 0.88 and 92% versus 99%, p = 0.12) between RT and ST. CONCLUSIONS: RT demonstrated excellent early outcomes compared with ST, and RT could also achieve comparable long-term oncologic outcomes with ST in thymic epithelial tumor. Therefore, RT should be considered as an alternative surgical option for treating anterior mediastinal masses.

Lymph Node Dissection in Thymic Malignancies: Implication of the ITMIG Lymph Node Map, TNM Stage Classification, and Recommendations.

OBJECTIVES: The aim of this study is to investigate the pattern of lymphatic metastasis and suggest a lymph node dissection (LND) strategy for thymic malignancies. METHODS: We retrospectively reviewed 131 thymic malignancy patients who had undergone LND. The recently introduced nodal map of the International Thymic Malignancy Interest Group/International Association for the Study of Lung Cancer and the TNM (tumor, node, metastasis) stage classification were used for grouping and staging the lymph nodes. The pattern of lymphatic metastasis and factors in lymphatic metastasis were investigated. RESULTS: Node metastasis was detected in 13 patients (N1 in six and N2 in seven). Six N2 patients (86%) had right paratracheal node (RPN) metastases. The rates of node metastasis were 1% at T1 and 37.5% at T2/3 (p < 0.001). The rates of node metastasis were 8% in the M0 and 43% in the M1 (p = 0.03). The rate was higher for thymic carcinoma (25%) than for thymoma (5.1%, p = 0.01), and the rates also differed between the subtypes of thymoma. There was no node metastasis of the A, AB, or B1 types. Tumor size was also a significant factor in node metastasis. The optimal cutoff value for the node metastasis was 6 cm and the specificity was 62%. Only 16% of the patients had received a preoperative histologic diagnosis. All patients with node metastasis had TNM stage II or higher thymic malignancy. The freedom from recurrence rate of the pN1/2 was significantly worse than that of the pN0 (5-year rate 38.5% versus 87.9%, p < 0.001). CONCLUSION: A status of stage II or higher was the most specific predictor of node metastasis, and the RPN was a crucial station for lymphatic metastasis in thymic malignancies. Thus, LND including RPN is recommended in stage II or higher thymic malignancies.