Systematic Mediastinal Lymph Node Dissection Research Articles

Surgical Choice for Clinical Stage IA Non-Small Cell Lung Cancer: View From Regional Lymph Node Metastasis

We aimed to investigate the pattern of regional lymph node (LN) metastasis of early-stage non-small cell lung cancer (NSCLC) to provide novel rationale for surgical choice (lobectomy, segmentectomy, or wedge resection) for these patients. We retrospectively collected clinical data of patients undergoing lobectomy with systematic mediastinal LN dissection or sampling for cT1N0M0 peripheral NSCLC from January 2015 to December 2018. The regional LN metastasis pattern was analyzed based on tumor size. We included a total of 354 patients for analysis. The rate of hilar or intrapulmonary LN metastasis was 13.6%. When stratified by tumor size, NSCLC less than or equal to 1 cm had no hilar or intrapulmonary LN metastasis (0%) while NSCLC greater than 2 cm but less than or equal to 3 cm had a significantly high rate of hilar or intrapulmonary LN metastasis (18.4%) and the rates of hilar, interlobar, and peripheral LN metastasis were also relatively high (5.4%, 5.4%, and 12.2%, respectively). NSCLC greater than 1.5 cm but less than or equal to 2 cm also had relatively high rates of hilar (6.5%) and peripheral (18.3%) LN metastasis, while NSCLC greater than 1 cm but less than or equal to 1.5 cm had significantly low rates of hilar or intrapulmonary (2.5%) and peripheral (2.5%) LN metastasis. Radiographic feature and histology were found to be independent predictors of regional LN metastasis. The pattern of regional LN metastasis in clinical stage IA peripheral NSCLC was significantly influenced by tumor size, which may provide evidence on surgical choice (lobectomy, segmentectomy, or wedge resection) for these early-stage NSCLC patients based on tumor size.

P2.17-42 Surgical Choice for Clinical Stage IA Non-Small Cell Lung Cancer: Novel Rationale from Intrapulmonary Lymph Node Metastasis Pattern

Current available surgical resection methods for early-stage NSCLC mainly consisted of lobectomy and sublobar resection (including segmentectomy and wedge resection) with lobectomy being the preferred option, which was established by the only completed RCT study finding that sublobar resection yielded a significantly higher recurrence rate and a trend toward worse survival than lobectomy. However, there are growing interest in observational studies and systematic reviews exploring the efficacy of sublobar resection in treating early-stage NSCLC, aiming to justify for applying sublobar resection as an alternative to lobectomy for treating these patients but with conflicting conclusions. We aimed to investigate the pattern of intrapulmonary lymph node (LN) metastasis of clinical T1N0M0 peripheral non-small cell lung cancer (NSCLC) to provide novel rationale for surgical choice (lobectomy, segmentectomy, or wedge resection) for these patients. We retrospectively collected clinical data of patients undergoing lobectomy with systematic mediastinal LN dissection or sampling for early-stage NSCLC from January 2015 to December 2018. The intrapulmonary LN metastasis pattern was analyzed by tumor size. We included a total of 354 patients for final analysis. The rate of intrapulmonary LN metastasis was 13.6% (Table 1). When stratified by tumor size, NSCLC ≤1cm had no hilar/intrapulmonary LN metastasis while NSCLC >2 but ≤3cm had significantly high rates of hilar/intrapulmonary LN metastasis (18.4%) and the rates of hilar, interlobar and peripheral LN metastasis were relatively high (5.4%, 5.4% and 12.2%, respectively). NSCLC >1.5cm but ≤2cm also had a relatively high rate of hilar (6.5%) and peripheral (18.3%) LN metastasis while NSCLC >1cm but ≤1.5cm had a significantly low rate of hillar/intrapulmonary (2.5%) and peripheral (2.5%) LN metastasis.Table 1Intrapulmonary lymph node metastasis pattern among clinical stage IA (cT1N0M0) peripheral non-small cell lung cancers with different tumor size.CharacteristicsTotal (N=354)Tumor size groupP value≤1cm (N=35)>1cm but ≤2cm (N=172)>2cm but ≤3cm (N=147)Total dissected N1 LN number (Mean±SD)5.6±3.03.6±1.95.4±2.76.3±3.3<0.001Total dissected N2 LN number (Mean±SD)8.1±4.07.0±3.47.6±3.68.8±4.40.008Lymph node metastasis rate16.9% (60/354)0 (0/35)14.5% (25/172)23.8% (35/147)0.002N1 LN metastasis rate (10-14#)13.6%(48/354)0(0/35)12.2%(21/172)18.4%(27/147)0.013Hilar LN metastasis rate (10#)4.2%(15/354)0(0/35)4.1%(7/172)5.4%(8/147)0.348Interlobar LN metastasis rate (11#)3.4%(12/354)0(0/35)2.3%(4/172)5.4%(8/147)0.263*Peripheral LN metastasis rate (12-14#)10.5%(37/354)0(0/35)11.0%(19/172)12.2%(18/147)0.092N2 LN metastasis rate (1-9#)8.8%(31/354)0(0/35)8.1%(14/172)11.6%(17/147)0.088Note: LN=lymph node; SD=standard deviation. *Fisher’s exact test Open table in a new tab Note: LN=lymph node; SD=standard deviation. *Fisher’s exact test Based on the pattern of intrapulmonary LN metastasis, our study provided novel perspectives on surgical choice of lobectomy, segmentectomy, or wedge resection for clinical stage IA peripheral NSCLC: for NSCLC ≤1cm both segmentecotmy and wedge resection could be utilized, and for NSCLC >1cm but ≤1.5cm segmentecotmy could be utilized provided that sufficient resection margin could be achieved; while for NSCLC >1.5cm lobectomy should be the preferred surgical option.

P2.16-16 Calf Circumference Is Associated with Postoperative Outcomes in Lung Cancer Patients Who Underwent Surgery

Sarcopenia has gained considerable attention as a poor prognostic factor in lung cancer after surgical resection. Calf circumference (CC) is an easy-to-measure, non-invasive clinical indicator that reflects body muscle mass as well as subcutaneous fat. For this property, many studies have reported that CC is capable of screening sarcopenia, aside from the assessment of nutritional status. In this study, we investigated the association between CC and postoperative outcomes in lung cancer patients. Between 2007 and 2016, 873 lung cancer patients underwent surgery in our institution. Patients who received induction therapy (n=33), with a prior history of the disease that could affect the diameter of lower limb (n=5), and with missing data (n=17) were excluded in advance, leaving 818 patients for this retrospective analysis. CC was measured prior to surgery in the occasion of hospital admission. We chose 34 cm for men and 33 cm for women as the CC cutoff value for predicting low muscle mass, following the previous report in Japan (Kawakami R et al. Geriatr Gerontol Int.). The patient characteristics, operative factors, and surgical outcomes were examined to compare the groups. The Kaplan-Meier method was used to estimate long-term survival. The mean age of all patients was 67.9 years. There were 473 men and 345 women, and each of their average CC was 34.4 cm and 32.0 cm. In the smaller CC (s-CC) group (n=427), the average age and the female proportion were significantly higher, whereas BMI, %VC, %FEV1 and %DLco, in addition to the proportion of the other cancer history were significantly lower (P<0.01 each) compared with the other group (n=391). As for operative factors, there were no significant differences in surgical approach, type of resection, operation time and intraoperative bleeding, except that the ratio of systematic hilar and mediastinal lymph node dissection was lower (P<0.01) in the s-CC group. Though overall postoperative complications were equivalent (27.2% vs. 23.0%), complications grade 3 or higher were more frequent in the s-CC group (10.5% vs. 5.9%, P=0.02). The 5-year DFS (65.1% vs. 77.9%, P=0.01) and OS (77.9% vs. 81.7%, P=0.03) were significantly poorer in the s-CC group. The smaller CC was associated with severe postoperative complications and poor DFS and OS in patients with resected lung cancer. CC was useful for assessing sarcopenia and therefore predicting postoperative outcomes.

The technique of thoracic lymph node dissection

Systematic mediastinal, hilar and interlobar lymph node dissection is required in the S3guidelines for the treatment of operable lung cancer. The lymph node involvement is considered one of the key prognostic factors. The type of lymph node resection is repeatedly the subject of controversially discussion. Lymph node dissection is essential for staging, prognosis, survival and recurrence rate. It should be standardized as a compartmental dissection with en bloc resection of lymph nodes including surrounding fat and connective tissue. Thus, exact knowledge of the anatomy of the thoracic organs with their peculiarities and high anatomical variability is necessary.

Ten-Year Trends of Clinicopathologic Features and Surgical Treatment of Lung Cancer in China

Lung cancer has changed significantly during the past 2 decades in its epidemiology and treatment. This retrospective analysis used data from 7 major areas of China over 10 years to evaluate clinicopathologic and surgical treatment trends of lung cancer in China during the past decade. Data from 7184 patients with primary lung cancer who were treated between 2005 and 2014 in 8 provinces of China were retrospectively collected. Their clinicopathologic features and surgical treatment information were recorded. Simple linear regression models and the Cochrane-Armitage trend test were used to assess temporal trends. The proportion of female patients (from 57.4% to 59.6%; P < .001) and nonsmoking patients (from 37.1% to 48.9%; P < .001) and of patients with a family history of malignant tumors (from 7.0% to 11.5%; P < .001) increased significantly. The percentage of adenocarcinomas increased significantly (from 36.4% to 53.5%; P < .001), with a decrease in squamous cell carcinomas (from 45.4% to 34.4%; P < .001). After 2008, the application of minimally invasive surgery significantly increased in China (from 2.4% in 2008 to 34.4% in 2014; P < .001), with a decline in the rate of conversion to open operation (from 14.3% in 2008 to 4.8% in 2014; P= .146) and an increase in the proportion of systematic mediastinal lymph node dissection (from 50.0% in 2008 to 84.1% in 2014; P= .001). This study investigated recent 10-year trends in the clinicopathologic features and surgical treatment of lung cancer in China and found significant important changes. These findings provide valuable information and evidence for the future control of the disease in China.

Systematic mediastinal lymph node dissection outcomes and conversion rates of uniportal video-assisted thoracoscopic lobectomy for lung cancer.

To evaluate the systematic mediastinal lymph node (LN) dissection outcomes and conversion rates of uniportal video-assisted thoracoscopic surgery (UVATS). Patients with non-small-cell lung cancer who underwent video-assisted thoracoscopic surgery (VATS) and systematic mediastinal LN dissection between January 2015 and January 2017 were retrospectively reviewed. We categorized the patients into two groups according to the different surgical approaches. Patients' clinical data were collected and compared. The index of estimated benefit from LN dissection was used to evaluate the therapeutic value of LN dissection for each station. A total of 453 patients underwent VATS, including 197 patients in the UVATS group and 256 patients in the triportal VATS (TVATS) group. There were no significant differences in the 1-, 2- and 3-year survival rates of these two groups (P > 0.05). There were no statistically significant differences in the operative time, numbers and stations of LNs, numbers and stations of N2 LNs, conversion rate or postoperative complications. The UVATS group had less intraoperative blood loss, a shorter duration of hospital stay, less chest tube drainage and a shorter duration of chest tube drainage than the TVATS group (P < 0.05). The conversion rates in the UVATS and TVATS groups were 5.1% and 4.3%, respectively, and the difference was not significant. The same degree of LN sampling was achieved in both groups. UVATS permits the same degree of LN sampling as TVATS without a difference in the conversion rate.

Late-onset bronchopleural fistula after lobectomy and adjuvant chemotherapy for lung cancer

Rationale:Late-onset bronchopleural fistula (BPF) induced by chemotherapy after lobectomy for lung cancer is rarely reported, lacking reliable preventive approaches. A timely identification and individualized treatment is essential for prognosis.Patient concerns:A 52-year-old female patient complained of fever, productive cough, and fatigue 1 week after adjuvant chemotherapy following right lower lobectomy and systemic mediastinal lymph node dissection. Chest computed tomography (CT) indicated pneumothorax and thick-walled empyema cavity within her right-sided thorax.Diagnoses:The patient was diagnosed as late-onset BPF based on clinical manifestation and chest radiography.Interventions:In addition to antibiotics, a chest tube was reinserted under CT guidance, and vacuum suction was utilized for continuous drainage. Next cycle of adjuvant chemotherapy was terminated.Outcomes:The empyema cavity was gradually closed in 1 month after conservative treatment, and the patient survived with good condition up to now.Lessons:Late-onset BPF should be kept in mind when the patient suffered from productive cough and chills during postoperative chemotherapy. And a prompt conservative management might be effective.

Lymph node metastasis outside of a tumor-bearing lobe in primary lung cancer and the status of interlobar fissures: The necessity for removing lymph nodes from an adjacent lobe.

The new Tumor Node Metastasis staging system does not recognize fissure status with respect to adjacent lobe invasion (ALI) in lung cancer. Furthermore, no specific surgical strategies have been recommended for lymph node dissections around adjacent nontumor-bearing lobes (NTBLs) according to fissure status. Therefore, this study was undertaken to investigate the necessity of removing additional adjacent lobe lymph nodes in patients with nonsmall cell lung cancer (NSCLC) for lesions limited to in the vicinity of the interlobar fissure.From August 2013 to March 2015, the records of 332 patients, who underwent systematic mediastinal lymph node dissection, were reviewed in this retrospective study. The bronchial lymph nodes had been subjected to pathological examination, and the status of the fissures was also recorded. A statistical analysis was performed to identify the significant predictors of lymph node metastasis.The patients were divided into a nonadjacent lobe invasion (NALI) group (n = 295) and an ALI group (n = 37). There was a significant difference in tumors with pN2 disease between the ALI and NALI groups (37.8% vs 8.8%, P = .001). ALI tumors had significantly more frequent pleural involvement than NALI tumors (62.2% vs 43.1%, P = .035). The frequency of N2 involvement among tumors invading across the complete fissure was higher than that of the tumors invading across the incomplete fissure (44.4% vs 14.3%, P = .015). However, the frequency of N1 involvement among tumors invading across the incomplete fissure was not statistically different than that of tumors not invading across incomplete fissure (32.1% vs 24.2%, P = .357). Regarding lymph node metastasis in NTBL, 15 (12.7%) patients had lymph node metastases in NTBLs. Pleural involvement was an independent predictor of lymph node metastasis in an NTBL.A greater frequency of N2 lymph nodes existed in NSCLC with invading adjacent lobe across complete fissure, extensive lymphatic resection within the hilum, and NTBL in tumors with pleural involvement are justifiable and necessary.

Video-Assisted Thoracoscopic Surgery versus open approach for systematic mediastinal lymph node dissection as surgical staging in major pulmonary resections for lung cancer

Video-Assisted Thoracoscopic Surgery versus open approach for systematic mediastinal lymph node dissection as surgical staging in major pulmonary resections for lung cancer

Application of the "continuous suture dividing and equal suture tightening" method in video-assisted thoracoscopic surgery sleeve lobectomy.

The primary focus of video-assisted thoracoscopic surgery (VATS) sleeve lobectomy is bronchial anastomosis. Both interrupted suture and continuous suture cannot overcome entanglement of the suture threads. The present study used the "continuous suture dividing and equal suture tightening" method in VATS sleeve lobectomy for bronchial anastomosis and discussed the feasibility of this approach. A total of 17 patients underwent VATS sleeve lobectomy with bronchial anastomosis using the "continuous suture dividing and equal suture tightening" method. Four incisions were utilized in the operation as follows: (I) the pulmonary arteries and veins were cut-off using an endoscopic linear stapler. Systematic hilar and mediastinal lymph node dissection was performed; (II) the surgeon used a surgical knife for incision into the thoracic cavity and to cut the lung lobe and main bronchi. Intraoperative pathological analysis revealed negative bronchial margins; (III) the "continuous suture dividing and equal suture tightening" method was performed for anastomosis; (IV) the integrity of the anastomosis was assessed by intraoperative bronchoscopy. Computed tomography (CT), three-dimensional (3D) reconstruction and bronchoscopy assessed the anastomosis 1-week postoperatively. A follow-up was conducted using a 3-month bronchoscopy, and CT scans monitored the recurrence and stenosis of the anastomosis. The method was successfully completed for VATS sleeve lobectomy with bronchial anastomosis in 17 cases. Although various histological profiles were observed, the 1-week postoperative CT and bronchoscopy showed adequate healing of the anastomotic stoma as well as the absence of postoperative mortality and bronchial pleural fistula. All patients were alive and followed up for 31-49 months postoperatively; local recurrence and anastomotic stenosis were not detected. The continuous suture dividing and equal suture tightening method is convenient, feasible, and safe for bronchial anastomosis in VATS sleeve lobectomy. It can effectively avoid the entanglement of the suture threads, thereby enabling the widespread adoption of VATS sleeve lobectomy.

Incidence and Distribution of Lobe-Specific Mediastinal Lymph Node Metastasis in Non-small Cell Lung Cancer: Data from 4511 Resected Cases.

We aimed to investigate the incidence and distribution of mediastinal lymph node metastases (MLNM) in operable non-small cell lung cancer (NSCLC) with the purpose of guiding mediastinal lymph node dissection (MLND). A total of 4511 NSCLC patients who underwent resection between January 2001 and December 2014 were included. These patients were preoperatively untreated and grouped according to the primary tumor lobes. The incidence and distribution of pathologic MLNM were compared among groups, and multivariate analysis was conducted to find the independent factors impacting MLNM. Lymph node involvement was observed in 1784 patients (39.5%). A total of 628 cases (13.9%) were N1-positive only, 752 cases (16.7%) were both N1- and N2-positive, and 404 cases (9.0%) were N2-positive only. The most common sites of mediastinal metastasis for different primary tumor lobes were the right upper lobe, station 4R (21.5%, 192/893); right middle lobe, station 7 (21.1%, 69/327); right lower lobe, station 7 (24.1%, 212/878); left upper lobe, station 5 (22.2%, 224/1008); and left lower lobe, station 7 (21.7%, 136/628). However, when only N2 cases were considered, each mediastinal lymph node zone can be involved with metastasis to a high proportion (>5%). Multivariable analyses showed that poor cell differentiation, adenocarcinoma, larger tumor size, central type, and younger age were independent factors favoring MLNM. Different primary tumor locations have a different propensity to be sites of MLNM; however, once MLNM occurs, each zone can be involved and should not be neglected. Systematic MLND is the preferred procedure for operable NSCLC.

Nodal involvement adversely affects prognosis in pulmonary carcinoid tumors

This study aims to analyze the prognostic factors affecting survival in pulmonary carcinoid tumors. Gender, age, smoking habit, comorbidity, localization of the tumor, T status, N status, histological type, and pathological stage of patients who had undergone resection of pulmonary carcinoid tumor between January 1, 2005 and December 31, 2016 were retrospectively reviewed. A total of 47 patients (18 male, 29 female; mean age 50.5 years; range, 23 to 74 years) consisting of 40 typical and 7 atypical carcinoid tumor cases were included in our study. Anatomical resection and systematic mediastinal lymph node dissection was performed on all patients. Pathological studies revealed lymphatic involvement in six patients (12.8%; 4 pN1 and 2 pN2). In the typical group (n=40), three patients were classified N1 (7.5%) and one patient N2 (2.5%). In the atypical group (n=7), one patient were classified N1 (14.3%) and one patient N2 (14.3%). Throughout the study, four patients with typical histology (10%) and two patients with atypical histology (28.6%) had nodal involvement. All six patients with nodal involvement underwent adjuvant radiotherapy. Atypical histology (p=0.005) and nodal involvement (p=0.008) were determined as negative prognostic factors in statistical analysis. Systematic hilar and mediastinal nodal dissection play a crucial role in the surgical treatment of pulmonary carcinoid tumors.

Retrospective study on video-assisted vs. open mediastinal lymphadenectomy for non-small cell lung cancer: a propensity-matched analysis.

This retrospective study is designed to compare the surgical outcomes of mediastinal lymph node (MLN) dissection between the two groups of non-small cell lung cancer (NSCLC) patients underwent lung cancer surgery through video-assisted thoracoscopic surgery (VATS) or thoracotomy, as well as classify the differences and identify the safer method between two groups. A total of 497 patients underwent pulmonary lobectomy and systemic MLN dissection were enrolled in this study. They were divided into VATS group (n=242) and traditional thoracotomy (TT) group (n=255). The VATS group received three-port VATS, while the thoracotomy group underwent posterior-lateral or muscle sparing thoracotomy. The range of MLN dissection included groups 2R, 4R, 7, 8, 9 in right-sided lung cancer surgery and groups 4L, 5, 6, 7, 8, 9 in left-sided. The two groups were matched at a ratio of 1:1 using the propensity score matching (PSM) method. Out of 497 patients, 376 cases were matched for PSM, with 188 cases in each group. Baseline date did not get any significant difference between two groups. The average group number of MLN dissection in VATS group and TT group was 4.14 and 3.97, respectively. While the average amount of dissected lymph nodes in both groups were 16.63 and 17.32, respectively. Compare with the lymph node numbers among all the groups in TT group, only the number of group 7 though left approach (7L) in VATS group was statically significant. Besides, the operation time and postoperative length of hospital stay in VATS group were superior to those in TT group (P<0.05). No significant difference had been found in intraoperative blood loss, accessory surgical injury and postoperative complication between two groups. Compared with thoracotomy, systemic MLN dissection and pulmonary lobectomy via VATS has quicker recovery, less postoperative complication and length of hospital stay with similar surgical outcomes. Moreover, our findings also suggest thoracotomy has an advantage on the dissection of MLN in group 7L.

Two-Stage Surgery Without Parenchyma Resection for Endobronchial Carcinoid Tumor

The aim of the study was to evaluate the efficacy of a combined approach of endoscopic resection followed by pure bronchoplasty without any pulmonary resection in patients with endobronchial carcinoids. We applied a two-stage technique, endoscopic resection first followed by pure bronchoplasty, to 25 patients (10 men, 15 women) with endobronchial carcinoid tumors. The median age was 32.4 years (range, 19 to 64). The indications for this technique were pure endobronchial carcinoid without lymph node involvement. Tumor was located on the right side in 18 patients (72%), and on the left in 7 patients (28%). Flexible bronchoscopy was carried out in all patients as the first-stage procedure for debulking and searching for a true pedicle of the tumor. Different types of pure bronchoplasty were performed as the second-stage surgery with systematic mediastinal lymph node dissection. The resection was complete (R0) in all cases. Tumors were pathologically staged as pT1aN0 in 18 patients, pT2N0 in 5, and pT3N0 in 2 patients; 23 tumors were typical and only two were atypical carcinoids. Morbidity was 28.0% (only minor complications), with no mortality. Overall 5-year and 10-year survival was 100.0% and 91.8%, respectively. No recurrence of the primary tumor was observed in any case. Two-stage surgery consisting of endoscopic resection and pure bronchoplasty without lung parenchyma resection is an effective technique for the treatment of endobronchial carcinoid, with an excellent oncologic outcome.

Outcomes, safety, and feasibility of video-assisted thoracic surgery in lung cancer patients on hemodialysis: a case series.

The rate of surgical resection of lung cancer in patients on hemodialysis is expected to increase due to the development of hemodialysis, improved diagnosis of lung cancer, and increases in the number and age of patients. However, studies assessing outcomes of lung resection in these patients are limited. In this retrospective case series, we investigated the safety and efficacy of video-assisted thoracic surgery (VATS) for lobectomy or segmentectomy for lung cancer in patients on hemodialysis. Between January 2010 and January 2017, lobectomy or segmentectomy using VATS was performed for seven lung cancer cases in six patients receiving hemodialysis at our institution. There were two female and five male patients, with a median age of 61years (range 53-76years). Six patients underwent lobectomy, and segmentectomy and wedge resection were performed in each one case, respectively; systematic mediastinal lymph node dissection (ND2a-2) was performed in six patients. There were no perioperative deaths in this case series. Median recurrence-free and overall survival rates were 20months (range 3-82months) and 31months (range 3-82months), respectively. Video-assisted thoracic surgery (VATS) is a safe and effective procedure for resection of lung cancer in hemodialysis patients and should be considered after accurate determination of surgical indications and careful perioperative management.

Impact of lymph node management on resectable non-small cell lung cancer patients.

A surgical lung resection with systematic mediastinal lymph node (LN) dissection is recommended by the National Comprehensive Cancer Network guideline. However, the effective number of dissected LNs, stations and positivity is still controversial. The aim of this study is to identify the impact of total numbers, LN stations and positivity of dissected LNs on tumor recurrence and overall death in resectable non-small cell lung cancer (NSCLC). This prognostic study used a retrospective data collection design. Adult patients with clinical resectable NSCLC who underwent pulmonary resection and mediastinal lymphadenectomy at Chiang Mai University between June 2000 and June 2012 were enrolled in this study. A multilevel mixed-effects parametric survival model was used to identify the effect of numbers, LN stations and positivity of dissected LNs to tumor recurrence and mortality. The average number of dissected LNs was 22.7±12.8. Tumor recurrence was found in 51.3% and overall mortality was 43.3%. The number of dissected LNs was a prognostic factor for tumor recurrence [HR 0.98, 95% confidence interval (CI): 0.96-0.99]. There was a significant difference at the cut-pointed value of 11 dissected LNs for tumor recurrence (HR 2.22, 95% CI: 1.26-3.92). Dissection less than 11 nodes and less than 5 stations indicated a poor prognostic factor for tumor recurrence: for 3-4 stations (HR 3.01, 95% CI: 1.22-7.42) and for 1-2 stations (HR 1.96, 95% CI: 1.04-3.72). The positivity of dissected LNs was also a prognostic factor for tumor recurrence and overall mortality (HR 1.01, 95% CI: 1.01-1.02 and HR 1.01, 95% CI: 1.01-1.03, respectively). Eleven or more LN dissection with at least 5 stations influenced recurrent-free survival. Systematic LN dissection (SLND) should be performed not only to identify the positivity of dissected LNs but also to determine an accurate tumor nodal stage. A larger cohort should be further conducted to support these findings.

Management of Pleural Space After Lung Resection by Cryoneuroablation of Phrenic Nerve: A Randomized Study.

Residual air space problems after pulmonary lobectomy are an important concern in thoracic surgical practice, and various procedures have been applied to manage them. This study describes a novel technique using controllable paralysis of the diaphragm by localized freezing of the phrenic nerve, and assesses the effectiveness of this procedure to reduce air space after pulmonary lobectomy. In this prospective randomized study, 207 patients who underwent lobectomy or bilobectomy and systematic mediastinal node dissection in our department between January 2009 and November 2013 were randomly allocated to a cryoneuroablation group or a conventional group. Patients in the cryoneuroablation group (n = 104) received phrenic nerve cryoneuroablation after lung procedures, and patients in the conventional group (n = 103) did not receive cryoneuroablation after the procedure. Data regarding preoperative clinical and surgical characteristics in both groups were collected. Both groups were compared with regard to postoperative parameters such as total amount of pleural drainage, duration of chest tube placement, length of hospital stay, requirement for repeat chest drain insertion, prolonged air leak, and residual space. Perioperative lung function was also compared in both groups. Recovery of diaphragmatic movement in the cryoneuroablation group was checked by fluoroscopy on the 15th, 30th, and 60th day after surgery. There was no statistically significant difference in patient characteristics between the 2 groups; nor was there a difference in terms of hospital stay, new drain requirement, and incidence of empyema. In comparison with the conventional group, the cryoneuroablation group had less total drainage (1024 ± 562 vs 1520 ± 631 mL, P < .05), fewer cases of residual space (9 vs 2, P < .05), fewer cases of prolonged air leak (9 vs 1, P < .01), and shorter duration of drainage (3.2 ± 0.2 vs 4.3 + 0.3 days, P < .01). Diaphragmatic paralyses caused by cryoneuroablation reversed within 30 to 60 days. Cryoneuroablation of the phrenic nerve offers a reasonable option for prevention of residual air space following major pulmonary resection.

ED08.01 Surgery of Early-Stage NSCLC

ED08.01 Surgery of Early-Stage NSCLC

ED15.03 Surgery of Thymic Malignancies

ED15.03 Surgery of Thymic Malignancies

P3.04-047 The Incidence and Outcome of Hoarseness after Systematic Upper Mediastinal Nodal Dissection by Radical Surgery for Primary Lung Cancer: Topic: Miscellaneous II

Recurrent laryngeal nerve (RLN) paralysis can occur following systematic upper mediastinal nodal dissection by radical surgery for primary lung cancer. However, there have been very few reports. We retrospectively reviewed the clinical data of 365 consecutive patients who underwent radical surgery for primary lung cancer with an over 6-month observation period in our institution from July 2010 to August 2015. There were 22 cases that experienced hoarseness after lung cancer surgery (6.0%). We could identify the movement of the vocal folds with a laryngoscope in 21 out of 22 cases (95.5%), because one patient refused to have the examination. Categorical variables were analyzed with Fisher’s exact test and continuous variables with the student’s-t test. P < 0.05 was considered statistically significant for all tests. Hoarseness subsequent to radical surgery for primary lung cancer arose in 16 out of 308 (5.2%) cases of video-assisted thoracic surgery (VATS) including robotic VATS, in contrast with six out of 88 cases (6.8%) of open thoracotomy. All patients who experienced hoarseness had received upper mediastinal nodal dissection. Patients who had received right upper nodal dissection experienced hoarseness in eight out of 150 cases (5.3%), in contrast to 14 out of 84 cases (16.3%, P = 0.020) for left upper lymph node dissection. Laryngoscopic examination revealed that five patients (23.8%) were diagnosed with right RLN paralysis and 15 (71.4%) as left. One patient who underwent VATS right upper lobectomy with upper mediastinal and subcarinal nodal dissection had left RLN paralysis. There was a patient (4.8%) who did not suffer from RLN paralysis, and one patient refused to undergo the examination. Eleven out of 18 patients (61.1%) were identified to improve the diagnosis of disorders of the vocal cords with the laryngoscope. It took one to 24 months (average 6.5 months) to improve the movement of the vocal cords observed with the laryngoscope. In addition, fourteen out of 19 cases (73.7%) were recognized for the improvement of their hoarseness. It took one to 28 months (average 10.4 months) to improve the voice disorder after surgery. In our cohort, 8.4% of patients who underwent systematic upper mediastinal lymph node dissection had hoarseness as a subjective symptom. However, 73.7% of patients who suffered from hoarseness and 62.5% of patients who were identified as having disorders of the vocal cords improved in more than two years.