**6. Lymph node dissection along the recurrent laryngeal nerve**

#### **6.1. ESCC**

**5. Lymph node metastasis along the recurrent laryngeal nerve**

**5.1. ESCC**

78 Esophageal Abnormalities

**5.2. EAC**

8 and 22% [22].

status in the UICC-TNM staging system [1].

Extensive lymphadenectomy with esophagectomy for esophageal carcinoma improves the prognosis in Japan. In particular, lymph nodes along the RLN are considered as significantly important lymph nodes those are recommended to be completely dissected. However, lymph node along the RLN dissection complicates high morbidity and mortality. Udagawa et al. showed lymph node metastasis along the rt. RLN and cervical paraesophageal at a rate of 31.9, 22.2%, 19, 13.9%, and 14.7, 12.4% of upper, middle, and lower thoracic esophagus, respectively. Lymph node metastasis along the lt. RLN and cervical paraesophageal was found at a rate of 19.1, 20.1%, 14.1, 8.3%, and 8.1, 5% of upper, middle, and lower thoracic esophagus in Japan, respectively [2]. Ye et al. reported that the recurrent laryngeal nerve lymph node metastasis from esophageal carcinoma is detected at the rate of 34.2% in China [21]. Lymph node metastasis along the recurrent laryngeal nerve was detected, and the rate of lymph node metastasis was 23.4%. The rate of rt. RLN lymph node metastasis was 20.8%, which was slightly higher than the rate of lt. RLN lymph node metastasis which had a rate of 15.8%.

In ESCC, lymph node metastasis is possible to occur in the neck, mediastinum, and abdomen. The location of RLN lymph node is from the upper mediastinum and to the cervical region, where lymph node metastasis is frequently detected in thoracic ESCC. Early, initial and micro metastasis of ESCC often occur and RLN lymph node metastasis has been regarded as an indication for three-field lymphadenectomy in the surgical treatment of ESCC. More importantly, RLN metastasis has been shown to be a strong predictor of poor prognosis in ESCC.

There are many reports about lymph node metastasis along the recurrent laryngeal nerve in Asia. In Japan, Igaki et al. reported that cervical or celiac lymph node metastasis in patients with carcinomas of the lower thoracic esophagus should be distinguished from pathologic M1

Giacopuzzi et al. reported that in Siewert type I tumors, when standard mediastinal lymphadenectomy is performed, about half of the node-positive patients show positive nodes in mediastinal stations [22]. Specifically, upper and mid mediastinal lymph node metastases (right paratracheal, subcarinal, aortopulmonary window) were reported in up to 25% of patients. When the few studies in which cervical nodes are also removed are considered, a non-negligible incidence of metastases is detectable, but, due to the scarcity of available data and the higher complication rate of three-field dissection, this is not currently thought to be relevant in clinical practice. Mediastinal nodes are involved in about 30% of Siewert type II cases. Although most of the positive nodes occur at lower stations, the rate of metastasis detected in the upper-mid mediastinum after transthoracic esophagectomy ranges between Surgeons in Asia, where the rate of ESCC is higher, perform lymphadenectomy along the recurrent laryngeal nerve. Udagawa et al. reported that cervical lymph node dissection had high efficacy index (EI) in upper and middle thoracic esophageal cancer but a low EI in lower esophageal cancer. Cervical lymphadenectomy for lower esophageal cancer showed some but limited efficacy only in cervical paraesophageal stations [2]. Three-field lymph node dissection may be indicated even for patients with clinical Stage I ESCC requiring surgical intervention because this surgical procedure offers possible cure by removing unsuspected lymph node metastasis. Altorki et al. also mentioned that three-field lymph node dissection with esophagectomy can involve with a low mortality and reasonable morbidity. Unsuspected metastases to the lymph nodes along the RLN and cervical region are present in 36% of patients in spite of histological tumor type or tumor location of the esophagus [23].

Osugi et al. reported that video-assisted thoracoscopic surgery (VATS), a less invasive method that preserves curability, provides comparable results to open radical esophagectomy. Palanivelu et al. demonstrated the lymph node dissection along the recurrent laryngeal nerve in prone position to be effective [24].

#### **6.2. EAC**

Lagergren et al. indicated that the extent of lymphadenectomy during surgery for esophageal carcinomas which include 83.5% adenocarcinoma may not influence 5-year all-cause or disease-specific survival [25]. These results challenge current clinical guidelines.

Feith et al. showed that a transthoracic approach followed by an extended lymph node dissection in the upper mediastinum is not recommended in patients with adenocarcinoma of the distal esophagus. Conservative surgical resection due to the virtual absence of lymph node metastasis in the upper mediastinum can cure patients with high-grade dysplasia and pT1a carcinoma. In addition systematic lymph node dissection of the lower posterior mediastinum and upper abdominal compartment can improve the prognosis in patients with more advanced tumors and a limited number of regional lymph node metastases. A transmediastinal approach with a wide splitting of the esophageal hiatus can achieve this radical lymph node dissection in the lower posterior mediastinum and upper abdominal compartment. Multimodal treatment protocols including chemotherapy and irradiation on systemic therapy are considered to be more appropriate for patients with more extensive lymph node metastases [25].

Cuscheri et al. recommended placing the patient prone to clear the posterior mediastinum, thus avoiding lung compression, but did not demonstrate lymph node dissection along the recurrent laryngeal nerve in EAC patients [26].

#### **6.3. Lymph node dissection along the rt. recurrent laryngeal nerve**

Thoracoscopic lymph node dissection along the right (rt.) recurrent laryngeal nerve has been more readily demonstrated by various authors. The rt. recurrent laryngeal nerve LN is removed as follows: the location of the right vagal nerve and the right inferior subclavian artery are confirmed. The airway behind the mediastinal pleura is opened to expose the right subclavian artery. The rt. recurrent laryngeal nerve is separated from the right vagal nerve followed by blunt dissection of the right recurrent laryngeal nerve through the vagus nerve trunk at the level of the right subclavian artery. We performed VATS-E in prone position (**Figure 1**). The surrounding LNs and fatty tissues are subsequently removed from the right recurrent laryngeal nerve [27] (**Figure 2**).

To reduce the risk of paralysis, an electric device is used to separate the nodes from the recurrent laryngeal nerve within 2 s [27].

#### **6.4. Lymph node dissection along the lt. recurrent laryngeal nerve**

Lymph nodes along RLNs are thought to be significantly involved by carcinoma cells as well as a main lymphatic chain to the neck, and complete dissection of these nodes is recommended. However, a lymphadenectomy, especially along the left RLN by thoracoscopic esophagectomy, is considered to be a burdensome step due to difficult operative exploration at the left upper mediastinum. To achieve a precise dissection of this portion, stable operative views and technical feasibility are necessary. Noshiro et al. mentioned that in their lymphadenectomy procedure along the left RLN, performing a thoracoscopic esophagectomy in the prone position had advantages compared to surgery in the left lateral decubitus position [27]. They introduced such details, during the procedure, the trachea is rolled back carefully and firmly to the right and ventrally by a grasper holding small gauze to explore the left aspect of the trachea and the left bronchus. The tissue, including the left RLN and lymph nodes, is

**Figure 1.** Port site in prone position. 3rd ICS, middle A.L.(1), 5th ICS, posterior A.L.(2), 7th ICS, posterior A.L.(3), 9th ICS, SSCL(4), 7th ICS, SSCL(5). ICS: inter costal space, AL: axillary line, SSCL: subscapular line.

Lymph Node Dissection along the Recurrent Laryngeal Nerve in Video-Assisted Thoracoscopic... http://dx.doi.org/10.5772/intechopen.69524 81

**Figure 2.** Lymph node dissection along the rt. RLN.

**6.3. Lymph node dissection along the rt. recurrent laryngeal nerve**

**6.4. Lymph node dissection along the lt. recurrent laryngeal nerve**

recurrent laryngeal nerve [27] (**Figure 2**).

rent laryngeal nerve within 2 s [27].

80 Esophageal Abnormalities

Thoracoscopic lymph node dissection along the right (rt.) recurrent laryngeal nerve has been more readily demonstrated by various authors. The rt. recurrent laryngeal nerve LN is removed as follows: the location of the right vagal nerve and the right inferior subclavian artery are confirmed. The airway behind the mediastinal pleura is opened to expose the right subclavian artery. The rt. recurrent laryngeal nerve is separated from the right vagal nerve followed by blunt dissection of the right recurrent laryngeal nerve through the vagus nerve trunk at the level of the right subclavian artery. We performed VATS-E in prone position (**Figure 1**). The surrounding LNs and fatty tissues are subsequently removed from the right

To reduce the risk of paralysis, an electric device is used to separate the nodes from the recur-

Lymph nodes along RLNs are thought to be significantly involved by carcinoma cells as well as a main lymphatic chain to the neck, and complete dissection of these nodes is recommended. However, a lymphadenectomy, especially along the left RLN by thoracoscopic esophagectomy, is considered to be a burdensome step due to difficult operative exploration at the left upper mediastinum. To achieve a precise dissection of this portion, stable operative views and technical feasibility are necessary. Noshiro et al. mentioned that in their lymphadenectomy procedure along the left RLN, performing a thoracoscopic esophagectomy in the prone position had advantages compared to surgery in the left lateral decubitus position [27]. They introduced such details, during the procedure, the trachea is rolled back carefully and firmly to the right and ventrally by a grasper holding small gauze to explore the left aspect of the trachea and the left bronchus. The tissue, including the left RLN and lymph nodes, is

**Figure 1.** Port site in prone position. 3rd ICS, middle A.L.(1), 5th ICS, posterior A.L.(2), 7th ICS, posterior A.L.(3), 9th ICS,

SSCL(4), 7th ICS, SSCL(5). ICS: inter costal space, AL: axillary line, SSCL: subscapular line.

dissected sharply just along the trachea and the left bronchus to make a ventral border of dissection. Finally, the left RLN is sharply isolated from the explored tissue without using an electric device to avoid injury by electricity or heat, and the lymph nodes were consequently dissected in an en-bloc fashion accompanied with the divided thoracic duct.

However, dissecting the lymph nodes along the left RLN during VATS is challenging and requires significant technical skill, and there is limited working space in the left upper mediastinum for dissecting the lymph nodes along the left RLN and expertise in dissection is required. The technique of lymph node dissection along the lt. RLN in VATS-E has been demonstrated by some authors (**Table 1**).

We have previously reported a "Stripping method" to overcome this disadvantage in prone position [28]. Therefore, we considered stripping the esophagus toward the neck to remove the esophagus. Both the esophagus and stomach tube in the upper mediastinum are cut apart from the tumor by a linear stapler after isolating the esophagus (**Figure 3A**). The residual esophagus is stripped in the reverse direction and retracted toward the neck when the stomach


**Table 1.** Methods of lymph node dissection along the RLN.

**Figure 3.** (A) Cutting both the esophagus and stomach tube. (B) Stripping by pulling the stomach tube.

**Figure 4.** (A) Lymph node dissection along the lt. RLN. (B) After LN dissection along the lt. RLN.

tube is removed through the nose by anesthesiologist (**Figure 3B**). The wide operative field of left upper mediastinum is possible using this stripping technique. Lymph node dissection is performed after stripping the residual esophagus [28, 29] (**Figure 4A**). Moreover, working space is created by compressing the right main bronchus or retracting the trachea using a retractor. Lymph node and fat tissue are ablated from the left edge of the trachea, after which lymph node along the left RLN is dissected (**Figure 4B**). An electrical device is used to separate the node from the nerve, and endoscopic scissors and forceps are used during sharp dissection along the nerve. One hundred patients with esophageal carcinomas underwent VATS-E (27 in left lateral position and 73 in prone position). This original technique of lymphadenectomy along the left RLN has been performed in 54 patients in the prone position VATS-E. The rate of transient recurrent laryngeal nerve palsy is 17.2%, but permanent palsy is only 1.2% [29].

Oshikiri et al. developed the "Bascule method" where the proximal portion of the divided esophagus and tissue that includes the left RLN and lymph nodes are drawn through a gap between the vertebral body and the right scapula [30]. The membranous portion between the esophagus and the trachea like the esophageal mesenteriolum is ablated by traction of the tissue including the left RLN and lymph nodes along the left RLN by the proximal esophagus. The lymph node along the left RLN is distinguished from the left RLN and the tracheoesophageal artery on the posterior side of the left RLN can be detected and easily cut by this traction technique. The esophageal mesenteriolum is possibly drawn by taping of the entire length of the undivided esophagus. However, there is a limit to the amount of retraction. Division of the esophagus increases the amount of retraction possible, allowing for further drawing and development of the operative field.

Xi et al. and Zheng et al. showed an esophageal suspension method in scavenging peripheral lymph nodes of the lt. RLN. In this method, a traction line is used to suspend the incompletely stripped esophagus [31, 32]. Tissues including the left RLN and lymph nodes were extended, which improved operative exposure. Tissue is released in the area close to the trachea and left main bronchus in order to dissect the ventral and cranial borders. The left RLN and LNs are easily recognizable. The lt. RLN to the thyroid gland and the lymph nodes along the left RLN are separated using endoscopic scissors, keeping the remaining lymph nodes attached to the esophagus.

Kaburagi et al. demonstrated hybrid position method that radical lymphadenectomy along the bilateral recurrent laryngeal nerves was performed in the left lateral decubitus position because this approach was superior for lymphadenectomy in the region. Thoracoscopic esophagectomy and other lymphadenectomy were provided in the middle to lower mediastinum in prone position [33].

Lin et al. reported that after looping the esophagus and fixation with a clip, the exposed thorax part of the thread is pulled up by the assistant to lift esophagus [34]. The left RLN is then exposed and separated in the space between lifted esophagus and the trachea. Scissor and isolating forceps are preferred during separation due to safety concerns. During subsequent mobilization of the esophagus and dissection of left RLN lymph nodes, the assistant uses the grasping forceps to compress the trachea so as to better expose the space between esophagus and trachea.

Fujiwara et al. reported that the lymph nodes along the left RLN could be separated from the left RLN trunk using endoscopic scissors under a mediastinoscope, with the nodes remaining attached to the esophagus [35]. First, the nerve trunk is exposed along the anterior plane, then, the lymph nodes are retracted to the left, through beneath the nerve trunk, and separated by dividing the attachment to the nerve trunk. Finally, the subaortic arch lymph nodes are dissected by dividing the attachment to the nerve trunk.

To avoid injury to the lt. RLN by electricity or heat, an electric device should not be used. Wong et al. demonstrated that a more aggressive and thorough nodal dissection may be possible with less concern of RLN injury by the availability of intermittent nerve mapping and continuous intraoperative nerve monitoring (CIONM) [36].
