Lymph node metastases outside tumor-bearing lobes and/or segments in non–small cell lung cancer

Objective

Hilar and lung lymph node metastases (N1) are defined as ipsilateral bronchial and intrapulmonary lymph nodes. However, the cleaning standards for ipsilateral bronchial lymph nodes in different lobes and segments within the same lobe in segmentectomy are not clearly defined.

Materials and methods

Sixty-six patients undergoing pulmonary resection for the treatment of lung cancer were evaluated. Intraoperatively visible non-tumor-bearing lobe (NTBL) and post-operatively non-tumor-bearing segment (NTBS) lymph nodes were removed and analyzed. The associations between the NTBL LNs and clinicopathological characteristics were analyzed.

Results

Non-tumor-bearing lobe LNs metastases were found in 8 (12.1%) of the 66 patients, NTBS LNs metastasis were not found (0/13). The presence of NTBL metastases was significantly associated with age (<60 years vs. ≥60 years, P = 0.037), differentiation (Grade 1 well differentiated vs. Grade 2 moderately differentiated vs. Grade 3 poorly differentiated, P = 0.012), CAT-scan-findings of Mediastinal and hilar lymph nodes metastasis (node-positive vs. node-negative, P = 0.022), pN stage (N0 vs. N1 vs. N2, P = 0.003) and p stage (I vs. II vs. III, P = 0.009). Multivariate logistic analysis showed that tumor differentiation (P = 0.048, HR 6.229; 95% CI 1.016–38.181) and pN (P = 0.024, HR 5.099; 95% CI 1.245–20.878) were statistically significant predictors.

Conclusions

Lobar lymph node metastasis of NTBL occurs frequently in patients with NSCLC, but lymph node metastases in NTBS LNs are rare. Advanced age, poorly differentiated and N1 and N2 status of CAT-scan-findings were independent risk factors for the involvement of the NTBL lobar lymph nodes. Although lymph node metastases in NTBS are rare, further investigation of the need to dissect is required.

[Advances in Lymph Node Metastasis and Lymph Node Dissection in Early Non-small Cell Lung Cancer]

肺癌是目前我国发病率和死亡率均居首位的恶性肿瘤，其中以非小细胞肺癌为主要病理类型。淋巴结转移是非小细胞肺癌最常见和最主要的转移途径，也是影响肺癌分期和预后最重要的因素。由于目前通过现有手段术前很难准确判断早期非小细胞肺癌患者的淋巴结受累情况。因此，在早期非小细胞肺癌中，尤其是在临床Ⅰ期非小细胞肺癌患者中，淋巴结清扫方式一直存在很大争议。本文就非小细胞肺癌淋巴结转移的规律及清扫方式进行综述。

Preoperative 3D-CT bronchography and angiography facilitates single-direction uniportal thoracoscopic anatomic lobectomy

Background

Competency in video-assisted thoracoscopic surgery (VATS) lobectomy is estimated to be reached after 50 cases. Preoperative identification of individualized pulmonary vascular drainage is essential for the safe and fluent performance of single-direction uniportal VATS (UVATS) anatomic lobectomy. Digital anatomy models established by three-dimensional computed tomography bronchography and angiography (3D-CTBA) is therefore utilized to accumulate variations of the right upper lobe (RUL) veins, as right upper lobectomy is considered to be the most complicated and challenging procedure. This study aims to investigate the perioperative outcomes and learning curve of single-direction UVATS RUL lobectomy assisted with 3D-CTBA.

Methods

The patients who underwent single-direction intercostal UVATS anatomic RUL lobectomy after 3D-CTBA simulation by the same surgeon at Xuzhou Central Hospital between January 2017 and April 2019 were retrospectively reviewed (3D-CTBA group), and consisted of 99 males and 54 females, with a mean age of 61.6 years, with the variations of the RUL vein being assessed preoperatively. They were further divided into group A (30 cases), B (30 cases), C (30 cases), and D (63 cases), in accordance with the order of surgery. Meanwhile, the first 35 cases of single-direction UVATS RUL lobectomy by another experienced surgeon (after the learning curve of this procedure) who did not use 3D-CTBA was enrolled as a control group. The operation time, intraoperative blood loss, stations and numbers of harvested lymph nodes, the incidence of conversion to multiport VATS or thoracotomy, thoracic tube retention for drainage, complications defined under the Clavien-Dindo system, pain score, and postoperative hospital stay were analyzed. The previous surgical experience of the two surgeons was also evaluated.

Results

A significant difference was evident among the 5 groups in terms of age, smoking history, the proportion of neoadjuvant chemotherapy, and T staging of the tumors (P<0.05, respectively). As for the 3D-CTBA group, a total of 29 cases (19.0%) of anomalous RUL posterior segmental pulmonary vein (PV) (V²) drainage were recorded, while the other 124 patients indicated the central type (V2a. Cent.). Of the uncommon RUL V², they could be further classified into 4 types [V2a. Post. (5/153, 3.3%), VX2a. Ant. (17/153, 11.1%), VXX2a. Ant. (3/153, 2.0%), and nonspecific complicated (4/153, 2.6%)]. Single-direction UVATS lobectomy was performed in every patient successfully. No perioperative mortality, major bleeding, conversion to thoracotomy, the addition of incisions, or 30-day unplanned readmission was recorded. One patient in group B reported an injury of a bronchial artery. All cases had an R0 resection. The operation time of group A (109.8±25.4 min) was significantly longer than that of group B (79.7±11.1 min), C (77.0±12.1 min), D (69.3±16.0 min), and the control (86.1±17.9 min, P<0.001 respectively). Moreover, the operation time of the patients in group B, C, and D was slightly shorter than the control, although without significance (P>0.05, respectively). Furthermore, the duration of chest tube drainage in group A (3.7±2.2 days) was noticeably longer than that in group B (3.0±0.9 days), C (2.7±1.6 days), D (2.6±0.8 days), and the control (2.7±1.6 days, P=0.004 among the groups). Similarly, postoperative hospital stay in group A (3.9±2.3 days) was noticeably longer than that in group B (3.0±1.0 days), C (2.8±1.8 days), D (2.6±0.8 days), and the control (2.8±1.8 days, P=0.002 among the groups). The 5 groups indicated comparable stations and numbers of the harvested lymph nodes, intraoperative blood loss, postoperative total chest drainage volume, incidence of complications, and pain scale on the 14^th day after surgery (P>0.05, respectively).

Conclusions

Preoperative 3D-CTBA digital anatomy facilitates the safe and fluent performance of single-direction UVATS anatomic right upper lobectomy, with a learning curve of 30 cases. High-quality trials for better evidence are called for to verify these findings.