Vegetable Preference and Prediction of Proteinuria: A Retrospective Cohort Study.

INTRODUCTION: Little information is available about the association between vegetable preference and chronic kidney disease. METHODS: This retrospective cohort study included 10,819 university workers in Japan who underwent their annual health checkups between January 2005 and March 2013. According to a question "Do you like vegetables"? with 3 possible answers of "I like vegetables," "I like vegetables somewhat," or "I dislike vegetables," 2,831, 2,249, and 104 male workers and 3,902, 1,648, and 85 female workers were classified into the "like," "somewhat," and "dislike" groups, respectively. An association between vegetable preference and incidence of proteinuria (dipstick urinary protein ≥1+) was assessed using Cox proportional-hazards models adjusted for clinically relevant factors. RESULTS: During the median observational period of 5.0 years, the incidence of proteinuria was observed in 650 (12.7%) male and 789 (14.1%) female workers. Among male workers, the "dislike" group had a significantly higher risk of proteinuria (multivariable-adjusted hazard ratio of "like," "somewhat," and "dislike" groups: 1.00 [reference], 1.05 [0.90-1.23], and 1.59 [1.01-2.50], respectively). Among female workers, vegetable preference was associated with the incidence of proteinuria in a dose-dependent manner (1.00 [reference], 1.20 [1.04-1.40], 1.95 [1.26-3.02], respectively). CONCLUSION: "Do you like vegetables"? was a clinically useful tool to identify subjects vulnerable to proteinuria.

[Indication and Results of 3-port Thoracoscopic Limited Resection for Lung Cancer].

The tumors with the size of 15 mm or less and less than 50 percent of solid component have been eligible for our radical surgical indication of 3-port thoracoscopic limited resection. The objective is to evaluate the indication. Between 2010 and 2015, we reviewed 206 segmentectomy and 87 partial resection. In those patients, non-radical limited resections included 129 segmentectomy and 29 partial resection. As for imaging findings, the maximum tumor diameter were 16.7 mm vs 10.8 mm and the consolidation/tumor (C/T) ratio were 0.54 vs 0.39. At a mean follow up of 48 months, 5-year overall survival (OS) were 91.4% vs 93.1%, and 5-year recurrent free survival (RFS) were 88.6% vs 93.1%. Overall recurrence(10 patients vs 6 patients) happened in the patients with non-radical limited resections for pure or part solid tumors, therefore it is necessary to consider an indication of limited resection for solid tumors carefully.

Peritoneal dialysis-associated infection caused by Mycobacterium abscessus: a case report.

BACKGROUND: Peritoneal dialysis (PD)-associated infection caused by Mycobacterium spp. is rare. Mycobacterium abscessus is one of the most resistant acid-fast bacteria, and treatment is also the most difficult and refractory. Thus, we report a case of PD-associated peritonitis caused by Mycobacterium abscessus that was difficult to treat and led to PD failure. CASE PRESENTATION: We recently encountered a 56-year-old man who developed PD-associated infection. We initially suspected exit-site infection (ESI) and tunnel infection (TI) caused by methicillin-resistant coagulase-negative Staphylococcus. However, antibiotic therapy did not provide any significant improvement. Thus, we performed simultaneous removal and reinsertion of a PD catheter at a new exit site. The patient subsequently developed peritonitis and Mycobacterium abscessus was detected in the peritoneal effluent. Thus, the reinserted catheter was removed, hemodialysis was started, and the patient was eventually discharged. CONCLUSIONS: In cases of refractory ESI or TI, it is important to consider non-tuberculous mycobacteria as the potentially causative organism. Even if acid-fast bacterial staining is negative or not performed, detection of Gram-negative bacillus may lead to suspicion and early identification of Mycobacterium spp. In PD-associated infection by Mycobacterium abscessus, catheter removal is necessary in many cases. Simultaneous removal and reinsertion of the catheter is not recommended, even in cases of ESI or TI. Reinsertion should only be attempted after complete resolution of peritoneal symptoms. After removal of the catheter, careful follow-up is necessary, paying attention to complications such as wound infection, peritonitis, and ileus. In addition, the selection and treatment period of antibiotics in PD-associated infection by Mycobacterium abscessus remains unclear, and it is an important topic for future discussion.

[Coronary-pulmonary Artery Fistula in a Hemodialysis Patient].

We report a case of coronary-pulmonary artery fistula in a hemodialysis patient treated surgically. A 47-year-old man was admitted with chest pain and exertional dyspnea that progressively worsened over the previous 2 months. He had a history of end-stage renal disease and has been on hemodialysis for 5 years. Coronary angiography and computed tomography revealed coronary-pulmonary artery fistula that originated from both the left anterior descending coronary artery and the right coronary artery. Under cardiopulmonary bypass, we opened the pulmonary artery and closed the fistula. The symptoms of the patient improved after the surgery, and he was discharged without major complications. Coronary-pulmonary artery fistulas in hemodialysis patients are rare. The presence of additional arteriovenous fistula used for dialysis in these patients increases the left-to-right shunt flow and might cause progression of heart failure. Even if the left-to-right shunt volume is small, surgical treatment is highly recommended at an early stage of the coronary-pulmonary artery fistula in hemodialysis patients.

[Thymoma Associated with Pure Red Cell Aplasia Treated with Ciclosporin as Remission-induction Therapy before Thymectomy].

A thymoma with pure red cell aplasia( PRCA) is relatively rare, and the treatment of the disease has not established yet. We describe a case of a thymoma associated with PRCA treated with a surgery and remission-induction therapy by ciclosporin. An 80-year-old man complained of dizziness and his blood cell count showed a severe anemia. He was diagnosed as PRCA by bone-marrow aspiration biopsy, which showed abatement of erythroblasts. In addition, the chest computed tomography revealed a solid tumor in the anterior mediastinum, strongly suggesting a thymoma. Oral administration of ciclosporin as remission-induction therapy for PRCA was started at 1st. The treatment contributed to partial remission for PRCA without blood transfusion. Consecutively thymectomy through median sternotomy was performed at 6 weeks after initiation of the treatment without any transfusions or complications. Histology of the solid tumor showed the thymoma of type B2 in World Health Organization (WHO) category. We continued to treat PRCA with ciclosporin after the surgery. The patient has been surviving for 2 years after surgery without any recurrence of thymoma or relapse of anemia. Combined therapy of surgery and remission-induction therapy with ciclosporin assumed to be a good strategy of the treatment for the patient with a thymoma associated with PRCA.

Diagnostic method of mass spectrometry for detecting lymph node metastasis of non-small cell lung cancer.

BACKGROUND: Histopathology by pathologists is essential in the diagnosis of non-small cell lung cancer (NSCLC). However, auxiliary diagnostic procedures for malignant tumor have continued to evolve. Despite the poor prognosis of patients with NSCLC, the application of the latest procedures and technologies to the field of lung cancer has lagged. Mass spectrometry was used to detect trace amounts of peptides in human tissue with high accuracy. The aim of this study was to establish a method for diagnostic mass spectrometry to identify lymph node metastasis by detecting cytokeratin (CK)19, a useful biomarker in lung cancer. METHODS: We collected 81 lymph nodes with positive expression of CK19 in patients who underwent radical surgical resection in the Department of Thoracic Surgery at Iwate Medical University between May 2020 and December 2022. An X500R instrument was used for sample analysis. A positive result for lymph node metastasis as the detection at least two product ions (FGPGVAFR and ILGATIENSR) from CK19 was defined. RESULTS: Our study indicated a high diagnostic efficiency for mass spectrometry, with 87.5% sensitivity and 91.2% specificity. The mutual concordance of mass spectrometry methods and histopathological diagnosis was 90.1%. CONCLUSIONS: Mass spectrometry offers high diagnostic accuracy and can be clinically applied to auxiliary diagnostic procedures for lymph node metastasis from NSCLC.

Elevated uric acid levels as a risk factor for new-onset hypertension in newly enrolled Japanese university students (JSH46-0100).

This study aimed to determine the association between serum uric acid (UA) levels and new-onset hypertension (HTN) in newly enrolled students (aged 18 to 20 years) at a university in Gifu, Japan. We analyzed data collected over a 12-year period from April 2010 to March 2022. From this dataset, we selected individuals who were normotensive at admission and underwent a follow-up examination four years later, at the time of their progression to a master's course (n = 2859). Among these participants, 75 (2.6%) developed HTN by the second visit. Their serum UA levels (mg/dL) were significantly higher compared to those who remained HTN-free, both at baseline (6.02 ± 1.06 vs. 5.42 ± 1.17) and at the second visit (6.10 ± 1.20 vs 5.46 ± 1.22). Logistic regression analysis revealed that the odds of developing HTN were higher when considering the mean UA level across both visits (odds ratio: 1.63 per 1 mg/dL increase) compared to either the first or second visit alone. Further analysis of the relationship between elevated mean UA levels (above the cutoff value of 5.7 mg/dL) and the risk of new-onset HTN demonstrated a significant odds ratio of 3.39, which remained significant after adjusting for body mass index and sex. In summary, elevated UA levels are an independent risk factor for future HTN in young adults.

Cystatin C as a Potential Blood Biomarker for Sarcoidosis: A Case Report.

Sarcoidosis is a multi-organ medical condition that is characterized by the formation of granulomas. We aimed to identify a correlation between each sarcoidosis blood biomarker and cystatin C (Cys-C) in sarcoidosis patients. We report a case of a 60-year-old man with sarcoidosis. The correlation between his Cys-C and each blood biomarker level and that between each blood biomarker and serum creatinine levels were determined using linear regression. Serum Cys-C correlated with each blood biomarker of sarcoidosis, while creatinine did not. These findings suggest that Cys-C is a potential blood biomarker for sarcoidosis.

Assessment of lymph node metastasis of ≤20 mm non-small cell lung cancer originating from superior segment compared to basal segment.

BACKGROUND: Segmentectomy with curative intention is occasionally performed for early non-small cell lung cancer (NSCLC). However, a major problem has been pointed out, in that the rate of locoregional recurrence is higher after segmentectomy than after lobectomy. This study aimed to investigate differences in rates of lymph node metastasis between segment 6 and basal segment NSCLC as potential candidates for segmentectomy and to explore factors associated with locoregional recurrence of segmentectomy. METHODS: We retrospectively analyzed 461 patients with lower lobe NSCLC who underwent segmentectomy or lobectomy with mediastinal lymph node dissection between 2011 and 2021. Among these, 122 patients with clinical N0 NSCLC, diameter ≤ 20 mm, and consolidation tumor ratio >0.5 were analyzed. RESULTS: The 122 patients were divided into a segment 6 group (n = 51) and a basal segment group (n = 71). Frequency of lymph node metastasis was significantly higher in the segment 6 group (17.7%) than in the basal segment group (4.2%; p = 0.01). Metastases to lymph node station 7 were seen in five of 122 patients (4.1%). Hilar lymph node metastasis occurred in nine of 122 patients (7.4%). Notably, metastases to station 11, 11i and 11 s lymph nodes were the most frequent patterns for hilar lymph nodes (41.7%). CONCLUSIONS: Station 11 lymph nodes are adjacent to the remaining lung segment or pulmonary artery in S6 segmentectomy or basal segmentectomy. Part of the NSCLC in segment 6 patients may thus be considered for lobectomy owing to the difficulty of complete dissection of station 11 lymph nodes.

Optimal period of smoking cessation to reduce the incidence of postoperative pulmonary complications in lung cancer.

OBJECTIVES: Postoperative pulmonary complications (PPCs) provoke an extended hospital stay and increased postoperative mortality. Although several factors can cause PPCs, smoking is the only factor that can be adjusted within a short period of time preoperatively. However, the optimal period of smoking cessation to reduce the risk of PPCs remains unclear. METHODS: A total of 1260 patients with primary lung cancer who underwent radical pulmonary resection between January 2010 and December 2021 were analysed retrospectively. RESULTS: We classified patients into 2 groups: non-smokers (patients who had never smoked) and smokers (patients who had ever smoked). The frequency of PPCs was 3.3% in non-smokers and 9.7% in smokers. PPCs were significantly less frequent in non-smokers than in smokers (P < 0.001). When smokers were classified according to the duration of smoking cessation, the frequency of PPCs was significantly lower for a duration of 6 weeks or more than for <6 weeks (P < 0.001). In a propensity score analysis performed for 6 or >6 and <6 weeks' smoking cessation in smokers, the frequency of PPCs was significantly lower for smokers with 6 or more weeks' smoking cessation than for smokers with <6 weeks' smoking cessation (P = 0.002). A multivariable analysis identified <6 weeks' smoking cessation as a significant predictor of PPCs for smokers (odds ratio: 4.55, P < 0.001). CONCLUSIONS: Smoking cessation for 6 or more weeks preoperatively significantly reduced the frequency of PPCs.

Surgical treatment for lung metastasis of inflammatory myofibroblastic tumor of the lung: A case report.

Inflammatory myofibroblastic tumor (IMT) is a rare disease that is considered an intermediate neoplasm, with the risk of recurrence and metastasis. Surgical treatment is the standard therapy for IMT, although there are only a few reports of surgery for lung metastasis of pulmonary IMT. We opine that surgical treatment might be effective not only for localized tumors, but also for cases of lung metastasis of IMT.

Living alone and prediction of weight gain and overweight/obesity in university students: a retrospective cohort study.

Objective:  To assess the clinical impact of living alone on weight gain in university students. Participants: This retrospective cohort study included 17540 male and 8854 female university students admitted to a national university in Japan. Methods: An association between living arrangement and the incidence of weight gain ≥10% and overweight/obesity (body mass index (BMI) ≥25 kg/m2) was assessed using multivariable-adjusted Poisson regression models. Results: Weight gain was observed in 1889 (10.8%) male and 1516 (17.1%) female students during 3.0 and 2.9 years of the mean observational period, respectively. Living alone was identified as a significant predictor of weight gain (adjusted incidence rate ratio of living alone vs. living with family: 1.24 [1.13-1.36] and 1.76 [1.58-1.95] in male and female students, respectively) and was also as a predictor of overweight/obesity. Conclusions: University students living alone were at a significantly higher risk of weight gain and overweight/obesity than those living with family.

Alcohol Consumption and a Decline in Glomerular Filtration Rate: The Japan Specific Health Checkups Study.

Previous studies have reported conflicting results on the clinical impact of alcohol consumption on the glomerular filtration rate (GFR). This retrospective cohort study aimed to assess the dose-dependent association between alcohol consumption and the slope of the estimated GFR (eGFR) in 304,929 participants aged 40-74 years who underwent annual health checkups in Japan between April 2008 and March 2011. The association between the baseline alcohol consumption and eGFR slope during the median observational period of 1.9 years was assessed using linear mixed-effects models with the random intercept and random slope of time adjusting for clinically relevant factors. In men, rare drinkers and daily drinkers with alcohol consumptions of ≥60 g/day had a significantly larger decline in eGFR than occasional drinkers (difference in multivariable-adjusted eGFR slope with 95% confidence interval (mL/min/1.73 m2/year) of rare, occasional, and daily drinkers with ≤19, 20-39, 40-59, and ≥60 g/day: -0.33 [-0.57, -0.09], 0.00 [reference], -0.06 [-0.39, 0.26], -0.16 [-0.43, 0.12], -0.08 [-0.47, 0.30], and -0.79 [-1.40, -0.17], respectively). In women, only rare drinkers were associated with lower eGFR slopes than occasional drinkers. In conclusion, alcohol consumption was associated with the eGFR slope in an inverse U-shaped fashion in men but not in women.

Evaluation of pulmonary artery bleeding during thoracoscopic pulmonary resection for lung cancer.

BACKGROUND: Bleeding from the pulmonary artery (PA) can be fatal in video-assisted thoracoscopic surgery (VATS) for lung cancer. We evaluated intraoperative PA injury and assessed precautions for thoracoscopic anatomic pulmonary resection. METHODS: We retrospectively analyzed a total of 1098 patients who underwent radical surgery for lung cancer utilizing complete VATS from January 2010 to December 2021. RESULTS: A total of 16 patients (1.5%) had PA injury during VATS, while hemostasis was performed by conversion to thoracotomy in eight patients (50.0%). Although there was a significantly greater operation time and blood loss for patients in the PA injury group (318.4 vs. 264.9 min, p = 0.001; 550.3 vs. 60.5 g, p ≤ 0.001, respectively), there was no significant different for the chest tube insertion duration and length of postoperative hospital stay (4.9 vs. 7.8 days, p = 0.157; 10.6 vs. 9.9 days, p = 0.136, respectively). There was a significant difference observed for the surgical procedure related to the left upper lobectomy in the PA injury group (43.8 vs. 18.8%, p = 0.012), with the primary causative PA determined to be the left anterior segmental PA (A3 ) (31.3%). CONCLUSIONS: VATS is both feasible and safe for lung cancer treatment provided the surgeon performs appropriate hemostasis, although fatal vascular injury could potentially occur during VATS. Surgeons need to be aware of the pitfalls regarding PA dissection management.

No-drain management after thoracoscopic lung wedge resection with a novel intraoperative sealing test.

OBJECTIVE: Although previous studies have reported the safety of no-drain management after thoracoscopic wedge resection, most of those studies were non-inferiority trials. The aim of this study was to evaluate whether no-drain management with an optimal sealing test affects post-operative complications in patients after thoracoscopic wedge resection. METHODS: A total of 906 patients who underwent thoracoscopic lung wedge resection for various disorders except secondary pneumothorax between 2011 and 2020 were analyzed. According to intraoperative findings from the sealing test, patients were divided into groups with chest drain placement (Drain group, n = 514) or no-drain management (no-drain group, n = 392). Our intraoperative sealing test used a flexible drain (Blake®, 19-Fr; Ethicon, Somerville, NJ) connected to the chest drain bag (- 10 cmH2O) to monitor intrathoracic pressure and detect occult alveolar air leakage. Propensity score matching was conducted to balance baseline characteristics of the two groups and reduce selection bias. RESULTS: A total of 250 pairs were matched and standardized differences suggested proper matching had been achieved. Mean length of post-operative hospital stay (4.6 days vs. 3.2 days, p < 0.001) was significantly lower in the no-drain group. Total post-operative complication rates were significantly lower in the no-drain group (6.4% vs. 2.4%, p = 0.03). CONCLUSIONS: No-drain management after thoracoscopic wedge resection was associated with fewer post-operative complications and shorter hospital stay in selected patients. Our novel intraoperative sealing test may be useful for no-drain management of select patients.

Skipping Breakfast and Incidence of Frequent Alcohol Drinking in University Students in Japan: A Retrospective Cohort Study.

Frequency of alcohol drinking is a potential predictor of binge drinking of alcohol, a serious social problem for university students. Although previous studies have identified skipping breakfast as a predictor of various health-compromising behaviors and cardiometabolic diseases, few studies have assessed the association between skipping breakfast and the incidence of frequent alcohol drinking. This retrospective cohort study included 17,380 male and 8799 female university students aged 18-22 years admitted to Osaka universities between 2004 and 2015. The association between breakfast frequency (eating every day, skipping occasionally, and skipping often/usually) and the incidence of frequent alcohol drinking, defined as drinking ≥4 days/week, was assessed using multivariable-adjusted Cox proportional hazards models. During the median observational period of 3.0 years, 878 (5.1%) men and 190 (2.2%) women engaged in frequent alcohol drinking. Skipping breakfast was significantly associated with the incidence of frequent alcohol drinking (adjusted hazard ratios [95% confidence interval] of eating every day, skipping occasionally, and skipping often/usually: 1.00 [reference], 1.02 [0.84-1.25], and 1.48 [1.17-1.88] in men; 1.00 [reference], 1.60 [1.03-2.49], and 3.14 [1.88-5.24] in women, respectively). University students who skipped breakfast were at a higher risk of frequent alcohol drinking than those who ate breakfast every day.

Correlation with spontaneous pneumothorax and weather change, especially warm front approaching.

BACKGROUND: Primary spontaneous pneumothorax (PSP) occurs more frequently in young, tall men, with approximately 10,000 times video-assisted thoracoscopic surgery (VATS) annually in Japan is undergoing for surgical treatment. The underlying mechanisms remain unclear, but several reports have suggested correlation with weather conditions. This study aimed to evaluate the relationship between onset of PSP and changes in weather. METHODS: We retrospectively analyzed data from 112 patients who underwent VATS for PSP in Iwate, Japan from 1 January 2010 to 14 June 2020. Of the 3,818 days in this study period, the day on which the patient became aware of symptoms was classified as the PSP onset day (n=112), and all others were classified as PSP non-onset day (n=3,706). Meteorological data were collected from airbase station using an online source for the same place and same time. Logistic regression modeling was used to obtain predicted risks for the onset of PSP with respect to weather conditions. RESULTS: Among the meteorological parameters, significant differences were mainly found at 2 days before onset for increasing average temperature [odds ratio (OR): 1.97, P=0.018], minimum temperature (OR: 1.97, P=0.018), average humidity (OR: 1.58, P=0.043), and decreased the sunshine time (OR: 2.26, P=0.012). No significant difference was observed in atrophic pressure at 2 days before onset. CONCLUSIONS: Onset of PSP may correlate with the increased temperature and humidity, seen with an approaching of warm front.

Effectiveness of CKD Exacerbation Countermeasures in Izumo City.

To diagnose chronic kidney disease (CKD) at an early stage, it is important to promote appropriate health guidance and consultation recommendations through regular medical examinations and implementation of continuous high-quality and appropriate treatment. From fiscal year (FY) 2018, Izumo City has initiated the "Izumo City CKD Exacerbation Countermeasures" program. In this study, we aimed to report on the methods undertaken and the effects of this program. Residents aged 40-74 years who underwent specific health checkups from the Izumo City National Health Insurance in FY2018 and FY2019 were included. The rates of CKD re-examination candidates, re-examinations implementation, nephrologist referrals, and health guidance referrals between FY2018 and FY2019 were compared. The rate of CKD re-examination candidates in both years remained unchanged at approximately 7%. The rate of re-examination implementation in FY2019 significantly increased relative to that in FY2018 (p < 0.001). Subsequent re-examination candidate trends showed that the rate of nephrologist referrals did not increase. However, the rate of city health guidance referrals significantly increased (p < 0.001). Increase in the re-examination and health guidance examination rates indicate improved awareness of CKD among the public and family doctors, and it is expected to prevent CKD exacerbation in the future.

Associations of kidney tests at medical facilities and health checkups with incidence of end-stage kidney disease: a retrospective cohort study.

No study has assessed the association between no health checkup and end-stage kidney disease (ESKD). This retrospective cohort study, including 69,147 adults aged ≥ 40 years in Japan who were insured by the National Health Insurance and the Late-Stage Medical Care System for the Elderly, assessed the associations of kidney tests at medical facilities and health checkups with incident ESKD. The main exposure was the histories of kidney tests using dipstick urinalysis and/or serum creatinine measurement at medical facilities and checkups in the past year: "checkups," "no kidney test (without checkup)," and "kidney tests (without checkup)" groups. During the median observational period of 5.0 years, ESKD was observed in 246 (0.8%) men and 124 (0.3%) women. The "no kidney test" group was associated with ESKD in men (adjusted subhazard ratio of "no kidney test" vs. "checkups": 1.66 [95% confidence interval, 1.04-2.65], but not in women. Age-specific subgroup analyses identified the "no kidney test" group as a high-risk population of ESKD in elderly men (1.30 [0.70-2.41] and 2.72 [1.39-5.33] in men aged 40-74 and ≥ 75 years, respectively). Elderly men with no kidney test at medical facilities and no health checkup were at higher risk of ESKD.

Validation of completion lobectomy after wedge resection for ≤20 mm non-small cell lung cancer.

BACKGROUND: Completion lobectomy after wedge resection is occasionally performed when final histopathology shows an unexpected primary lung cancer even though the primary lesion has already been resected. The objective of this study was to assess the necessity of completion lobectomy after wedge resection for ≤20 mm non-small cell lung cancer (NSCLC). METHODS: Between 2006 and 2016, a total of 112 patients with NSCLC underwent wedge resection in our department. After exclusions, 40 patients were analyzed. Of these, 17 patients underwent completion lobectomy and 23 patients underwent wedge resection alone. Age, sex, tumor size, histology, other malignant diseases and final surgical procedure were used as prognostic variables. Survival analyses were confirmed using the Kaplan-Meier method and log-rank test. RESULTS: Median follow-up was 70.4 months. No significant difference in 5-year overall survival (OS) and relapse-free survival (RFS) were seen in patients who underwent wedge resection alone compared to the completion lobectomy group (OS: 72.6% vs. 62.5%, P=0.34; RFS: 64.2% vs. 50.0%, P=0.35). Multivariate analysis identified age (>65 years old) and male sex as independent prognostic factors for OS and RFS. CONCLUSIONS: Completion lobectomy after wedge resection did not impact OS or RFS compared with wedge resection alone in patients with ≤20 mm NSCLC. These findings suggested that selected patients may not require resection of the remaining lobe or lymph node dissection after initial wedge resection.