Changing the Dissectable Layer: Novel Thoracoscopic Esophagectomy Method for Lymphadenectomy along the Left Recurrent Laryngeal Nerve

Improvement Effect of Upper Mediastinal Lymphadenectomy During Minimally Invasive Esophagectomy on the Prognosis in Squamous Cell Carcinoma: Efficacy Index and Propensity Score Matching Analyses

BACKGROUND

The effect of lymphadenectomy around the recurrent laryngeal nerve (RLN) in open esophagectomy has been demonstrated with the efficacy index (EI). However, it remains unclear whether this effect exists for minimally invasive esophagectomy (MIE) in the prone position. The purpose of this study was to clarify whether the upper mediastinal lymphadenectomy contributed to improved prognosis in patients with esophageal squamous cell carcinoma.

STUDY DESIGN

This study included 339 patients with esophageal squamous cell carcinoma treated with MIE in the prone position at Kobe University or Hyogo Cancer Center, Japan, from 2010 to 2015. EIs for each station, correlations between metastatic lymph nodes around the left RLN and RLN palsy, and survival of patients with and without upper mediastinal lymphadenectomy were investigated.

RESULTS

Among 297 patients treated with upper mediastinal lymphadenectomy, Clavien- Dindo grade ≥ II left RLN palsy occurred in 59 patients (20%). Overall, EIs for the right RLN (7.4) and left RLN (6.6) were higher than EIs for other stations. For patients with upper-third or middle-third tumors, the trend was stronger. Left RLN palsy was more likely in patients with metastatic lymph nodes around the left RLN than in those without (44% vs 15%, p < 0.0001). After propensity score-matching, 42 patients were included in each group with and without upper mediastinal lymphadenectomy. In survival analyses, the 5-year overall survival rates were 55% vs 35% and cause-specific survival rates were 61% vs 43% for the patients with and without upper mediastinal lymphadenectomy respectively. Significant differences were confirmed in survival curves (overall survival: p = 0.03; cause-specific survival: p = 0.04, respectively).

CONCLUSIONS

Upper mediastinal lymphadenectomy contributes to improved prognosis with high EIs in MIE in the prone position.

Histological categorisation of the desmoplastic reaction is a predictor of patient prognosis in oesophageal squamous cell carcinoma

AIMS

Histological categorisation of the desmoplastic reaction (DR) is an independent prognostic factor in colorectal cancer. However, it is unknown whether DR categorisation is predictive of oesophageal squamous cell carcinoma (OSCC) outcomes. This study aimed to evaluate the prognostic value of DR categorisation in OSCC patients.

METHODS AND RESULTS

Data were collected from 118 patients with OSCC who underwent a curative oesophagectomy with T2 or deeper wall invasion. The DR in each tumour was classified as mature, intermediate or immature based on the presence or absence of keloid-like collagen and myxoid stroma. We identified 49 mature DR tumours, 41 intermediate DR tumours and 28 immature DR tumours. The 5-year overall survival (OS) rate was highest in the mature DR group (42.8%), followed by the intermediate DR group (25.0%) and the immature DR group (19.9%) (P = 0.022, log-rank test; P = 0.006, log-rank trend test). The 5-year disease-specific survival (DSS) rate was also highest in the mature DR group (48.5%), followed by the intermediate DR group (30.8%) and the immature DR group (26.8%) (P = 0.031, log-rank test; P = 0.010, log-rank trend test, respectively). Multivariate analysis revealed that an immature DR was an independent poor prognostic factor of OS and DSS (P = 0.002 and P = 0.004).

CONCLUSIONS

DR categorisation of OSCC stroma following oesophagectomy is a useful diagnostic tool and an independent prognostic marker.

Novel "Modified Bascule Method" for Lymphadenectomy Along the Left Recurrent Laryngeal Nerve During Robot-Assisted Minimally Invasive Esophagectomy

BACKGROUND

Given the worldwide popularization of conventional minimally invasive esophagectomy (C-MIE), robot-assisted MIE (RAMIE) can be expected to provide a finer procedure. However, controversy remains regarding whether RAMIE is superior to C-MIE in preventing recurrent laryngeal nerve (RLN) palsy. Considering the shallow learning curve for RAMIE, a novel procedure for lymphadenectomy along the RLN during RAMIE is needed.

METHODS

Based on a logical and simple understanding of the left upper mediastinum anatomy, the authors developed a novel "modified bascule method" for RAMIE that could simplify lymphadenectomy along the left RLN and prevent it from being touched and stretched. Between 2018 and 2020, 46 patients with esophageal carcinoma underwent RAMIE using this method at Kobe University.

RESULTS

The modified bascule method was used to perform RAMIE for 29 men and 17 women with a median age of 67 years (range, 49-82 years). The median thoracoscopic procedure time was 438 min (range, 344-625 min), and the median console time was 351 min (range 273-518 min). The study harvested a median of 24 (range, 8-34) lymph nodes from the thoracic portion and 4 (range, 0-10) lymph nodes from along the left RLN. The mortality rate was 0%. Postoperative left RLN palsy classified as Clavien-Dindo (C-D) grade 1 or higher was observed for 9 patients (19%), whereas grade 2 or higher was not seen (0%). Pneumonia and anastomotic leakage rates higher than C-D grade 2 were respectively 13% and 19%.

CONCLUSIONS

The novel modified bascule method for RAMIE can promote feasible lymphadenectomy along the left RLN even when performed during the learning period.