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prevention of loco-regional recurrence. We herein briefly review the current status of robotic
esophagectomy (RE) and share our institute’s outcomes, primarily focused on the dissection of the LNs
along the RLN.

HISTORICAL BACKGROUND
Historically, radical LN dissection in the upper mediastinum was documented during the 1980s and
[1]
1990s . This surgical procedure gained significant popularity, particularly in Japan; however, it was
infrequently performed in Western countries. A seminal contribution to the field is represented by a key
paper published in the Annals of Surgery in 1994 by Akiyama et al., distinguished experts in esophageal
cancer surgery. In this publication, Akiyama et al. reported on radical LN dissection techniques employed in
esophageal cancer, marking a pivotal advancement in the understanding of this specialized surgical
approach .
[2]

The authors documented the metastatic patterns of esophageal cancer based on the primary tumor’s
location. One of the key findings of this study is the notable prevalence of metastasis to the upper
mediastinum and cervical LNs, with the RLN vicinity being the most common site of metastasis.
Consequently, the authors conducted a radical LN dissection, now referred to as three-field LN dissection.
Japanese surgeons pioneered this technique, reporting highly favorable outcomes postoperatively. In this
paper, the authors conducted a comparative analysis of long-term survivals between two-field and three-
field LN dissections, revealing that three-field LN dissection yields superior overall survival compared to
two-field LN dissection. However, caution must be exercised in interpreting these findings due to the
study's non-randomized design. The authors initially performed two-field LN dissection in the earlier cases
and transitioned to three-field LN dissection in the later cases. This lack of randomization introduces a
potential bias that needs careful consideration. Nevertheless, following the publication of this paper, three-
field LN dissection has gained widespread popularity in Japan, and in several institutes in other countries, it
is now performed as a routine procedure for esophageal cancer surgery.

Japanese surgeons also assessed the efficacy index of mediastinal and abdominal LNs in esophageal cancer
[3]
surgery . The efficacy index is calculated by multiplying the incidence of metastasis and long-term survival,
signifying that a higher efficacy index for a LN station indicates greater effectiveness of dissection for that
station compared to others. In a study composed of 3,827 patients , examining the efficacy index based on
[4]
the location of the primary tumor reveals that, in upper mediastinal esophageal cancer, the highest efficacy
index is identified in the upper mediastinal LN area, which covers the recurrent laryngeal LN area.
Consequently, for upper and middle esophageal cancer, the recurrent laryngeal LN area emerges as the most
effective region, demonstrating both a high metastasis rate and significantly higher long-term survival rates
following LN dissection. Even in lower esophageal cancer, the efficacy index of the upper mediastinal area
remains high, underscoring the necessity of upper mediastinal LN dissection for all esophageal cancer cases
[Table 1]. Also, a recent study conducted by Japanese surgeons elucidated the efficacy index of each regional
LN station based on the results of 612 esophagectomy patients . The right RLN LN station showed the 1st
[5]
highest efficacy index and the left RLN LN station showed the 6th highest efficacy index out of 26 regional
LN stations. This study in detail highlights the utmost importance of both recurrent laryngeal LN dissection
in esophageal cancer surgery.

CURRENT GUIDELINES
[6]
The Japanese Esophageal Society has provided guidelines regarding the extent of LN dissection . In
accordance with the 11th edition of guidelines, the committee recommends D2 dissection for esophageal
cancer, where D2 signifies dissection to the extent of Group 2, denoted by the color blue [Figure 1]. As per