Yoohwa Hwang

Importance of lymph node dissection in thymic carcinoma.

BACKGROUND Lymph node dissection plays important role in oncologic surgery. We investigated outcomes of lymph node dissection in thymic carcinoma. METHODS We retrospectively reviewed 37 patients, who underwent complete resection for thymic carcinoma. Patients were divided into four groups: no node dissection (Nx), 8; pathologic N0 by limited dissection (N0a), 13; pathologic N0 by extensive dissection (N0b), 10; and node metastasis (N1), 6. Outcomes of lymph node dissection were investigated. Disease-free survival (DFS) and freedom from recurrence of the four groups were compared. RESULTS A total of 349 lymph nodes were dissected in 29 patients. Metastasis was confirmed in 19 nodes in 6 patients, with tumor invading adjacent organs. Anterior mediastinal lymph node metastasis was confirmed in 4 patients. Intrathoracic lymph node metastasis was confirmed in 3 patients at the right paratracheal lymph nodes. Recurrences were diagnosed in 11 patients (Nx, 2; N0a, 4; N0b, 1; N1, 4). The 5-year overall survival rate was 65.5%, DFS was 60.9%, and freedom from recurrence was 68.2%. DFS rates of the N0b subgroup were significantly better than in the N1 subgroup (90% vs 33.3%). DFS rates of the Nx and N0a subgroups were similar (75% vs 48.7%, p=0.98), and the prognoses of both groups were intermediate between the N0b and N1 groups. Analyses of freedom from recurrence proved identical results. CONCLUSIONS Extensive lymph node dissection, meaning dissection of more than 10 lymph nodes, is required to predict prognosis accurately. Anterior mediastinal and right paratracheal lymph nodes should be dissected in thymic carcinoma.

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.

Reverse V-Shape Kinking of the Left Lower Lobar Bronchus after a Left Upper Lobectomy and Its Surgical Correction

A 76-year-old male underwent a left upper lobectomy with wedge resection of the superior segment of the left lower lobe using video-assisted thoracoscopic surgery (VATS) for non-small-cell lung cancer of the left upper lobe. He presented with shortness of breath, fever, and leukocytosis. Chest radiography showed atelectasis at the remaining left lower lobe. Bronchoscopy revealed narrowing of the left lower bronchus with purulent secretion, and computed tomography showed downward kinking of the left lower lobar bronchus. He underwent exploratory VATS, and intraoperative findings showed an inferiorly kinked left lower lobar bronchus with upward displacement of the left lower lobe. After adhesiolysis, the kinked bronchus was straightened, and bronchopexy was performed to the pericardium to prevent the recurrence of bronchial kinking. Also, the inferior pulmonary ligament was reattached to prevent upward displacement. Postoperative follow-up bronchoscopy revealed no evidence of residual bronchial obstruction, and chest radiography showed no atelectasis thereafter.

Comparison of thoracoscopic segmentectomy and thoracoscopic lobectomy on the patients with non-small cell lung cancer: a propensity score matching study.

OBJECTIVES Thoracoscopic lobectomy has been widely performed on patients with early-stage lung cancer; meanwhile indications of thoracoscopic segmentectomy have not been clearly defined due to technical difficulties and unclear oncological outcomes. The aim of this study was to compare early and late outcomes between thoracoscopic segmentectomy and thoracoscopic lobectomy. METHODS Between January 2005 and December 2013, 100 thoracoscopic segmentectomies and 1049 thoracoscopic lobectomies were performed on patients with lung cancer in our institute. Preoperative clinical parameters including gender, age, tumour size, pathological stage, histology and forced expiratory volume in 1 s (FEV1) were used for propensity score matching. After propensity score matching, 94 thoracoscopic segmentectomies and 94 lobectomies were selected and compared. RESULTS Thoracoscopic segmentectomies were performed on patients with normal lung function (mean FEV1 = 101.6 ± 24.1%), small-sized tumour (mean diameter 1.7 ± 1.0 cm), early-stage cancer (Stage I 93.7%) and predominant adenocarcinoma (81.9%). The lobectomy group had similar clinical features with the segmentectomy group. Most commonly performed procedures were left upper lobe upper division segmentectomy (19%) and right lower lobe superior segmentectomy (17%). Segmentectomies were performed in all lobes except the right middle lobe. There were no differences between segmentectomy and lobectomy in terms of operation time (166.3 ± 54.7 min vs 181.1 ± 85.2 min, P = 0.47) and hospital stay (6.2 ± 5.2 days vs 7.1 ± 7.1 days, P = 0.31). Incidence of postoperative complications was non-significantly higher in the lobectomy group (17.2 vs 10.6%, P = 0.1), and postoperative mortality rates were also non-significantly higher in the segmentectomy group (1.1 vs 2.1%, P = 0.56). Postoperative FEV1 decrease was non-significantly lower in the segmentectomy group (8.9 ± 10.8 vs 11.0 ± 13.1, P = 0.36). The 3-year overall survival and recurrence-free survival was not different between the two groups (94 and 87% in the segmentectomy group and 96 and 94% in the lobectomy group, P = 0.62 and P = 0.69, respectively). CONCLUSIONS Thoracoscopic segmentectomy could achieve equal short-term surgical results and long-term oncological outcomes compared with thoracoscopic lobectomy.

Limited thymectomy as a potential alternative treatment option for early-stage thymoma: A multi-institutional propensity-matched study

OBJECTIVES For early-stage thymoma, complete thymectomy has classically been regarded as the standard treatment protocol. However, several studies have shown that limited thymectomy may be an alternative treatment option for thymoma. This study compared perioperative outcomes, survival, and recurrence rates between patients undergoing limited thymectomy and complete thymectomy. MATERIALS AND METHODS Between January 2000 and December 2013, a total of 762 patients underwent thymectomy for stage I or II thymomas at four institutions participating in the Korean Association for Research on the Thymus. Patients were divided into two groups: limited thymectomy group (n=295) and complete thymectomy group (n=467). Comparative clinicopathological, surgical, and oncological features were reviewed retrospectively. RESULTS The median follow-up time was 49 months (range: 0.2-189 months). A propensity score-matching analysis, based on seven variables (age, sex, surgical approach, tumor size, WHO histological type, Masaoka-Koga stage, and adjuvant radiotherapy), was performed using 141 patients selected from each group. The 5- and 10-year freedom-from-recurrence rates in the limited thymectomy group were 96.3% and 89.7%, respectively, and those in the complete thymectomy group were 97.0% and 85.0%, respectively. No significant differences in these rates were observed between groups (p=0.86). A multivariate Cox regression analysis showed that overall survival and freedom-from-recurrence rates did not significantly differ by surgery extent (p=0.27, 0.66, respectively). Perioperative outcomes were better in the limited thymectomy group. CONCLUSION Limited thymectomy was not inferior to complete thymectomy with respect to recurrence, and had better perioperative outcomes. Limited thymectomy may be a viable treatment option for early-stage thymoma.

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

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.

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

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.

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.

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.

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.