Vagus nerve and phrenic nerve guided systematic nodal dissection for lung cancer.

Abstract

Systematic nodal dissection (SND), which is defined as “all the mediastinal tissues containing the lymph nodes are dissected and removed systematically within anatomical landmarks”, is vital in surgical treatment for patients with non-small cell lung cancer (NSCLC) with curative intent (1). However, for avoiding surgical complications or other reasons, a variation of SND affects the thoroughness of lymph node dissection and the accuracy of pathologic nodal (pN) staging, which are the most significant prognostic factors in resectable NSCLC (2,3). Also, reduction in the severity and incidence of postoperative complications, such as nerve injury, is of utmost importance and remains challenging (4). Although some studies reported the experience and skills in mediastinal lymph node dissection (4,5), a standard and systematic procedure for nerve protection are still lacking. Therefore, an easy-to-follow standardized approach of SND, which can not only achieve regional en bloc lymph node resection but also effectively protect the nerves, is critically needed. Based on clinical practice experience, we discovered that the hilar and mediastinal lymph nodes are distributed along with the courses of these two nerves and connected in some anatomical regions (Figure 1). Thus, we first divided the lymph nodes into three areas of each side and developed an improved approach named “duo-nerve-guided SND” for resectable lung cancer, aiming to easily achieve complete resection of hilar and mediastinal lymph nodes as well as adipose tissue without increasing the nerve-related complications. Open in a separate window Figure 1 The anatomy of the thoracic vagus nerve and phrenic nerve and the distribution of lymph nodes. (A,C) The hilar and mediastinal lymph nodes were distributed along the vagus and phrenic nerves as well as their anatomical thoracic branches (pulmonary plexus, cardiac plexus, and esophageal plexus); (B,D) the regional lymph nodes distribution. Area A (green), the posterior area of the hilum; area B (blue), the anterior area of the hilum; area C (red), the anterior mediastinal area for the left side, the superior mediastinal area for the right side. (E) The subcarinal lymph nodes in left side (station 7); (F) the station 4L lymph nodes. RVN, right vagus nerve; LVN, left vagus nerve; LRLN, left recurrent laryngeal nerve.