Mesenteric excision for esophageal cancer surgery: based on the concept of mesotracheoesophagus

Technical feasibility and oncological outcomes of robotic esophagectomy compared with conventional thoracoscopic esophagectomy for clinical T3 or T4 locally advanced esophageal cancer: a propensity-matched analysis

BACKGROUND

Minimally invasive esophagectomy is the first-line approach for esophageal cancer; however, there has recently been a paradigm shift toward robotic esophagectomy (RE). We investigated the clinical outcomes of patients who underwent RE compared with those of patients who underwent conventional minimally invasive thoracoscopic esophagectomy (TE) for locally advanced cT3 or cT4 esophageal cancer using a propensity-matched analysis.

METHODS

Overall, 342 patients with locally advanced cT3 or cT4 esophageal cancer underwent transthoracic esophagectomy with total mediastinal lymph node dissection between 2018 and 2022. The propensity-matched analysis was performed to assign the patients to either RE or TE by covariates of histological type, tumor location, and clinical N factor.

RESULTS

Overall, 87 patients were recruited in each of the RE and TE groups according to the propensity-matched analysis. The total complication rate and the rates of the three major complications (recurrent laryngeal nerve paralysis, anastomotic leakage, and pneumonia) were not significantly different between the RE and TE groups. However, the peak C-reactive protein concentration on postoperative day 3, rate of surgical site infection, and intensive care unit length of stay after surgery were significantly shorter in the RE group than in the TE group. No significant differences were observed in the harvested total and mediastinal lymph nodes. The total operation time was significantly longer in the RE group, while the thoracic operation time was shorter in the RE group than in the TE group. There was no significant difference between the two groups in the recurrence rate of oncological outcomes after surgery.

CONCLUSION

RE may facilitate early recovery after esophagectomy with total mediastinal lymph node dissection and has the same technical feasibility and oncological outcomes as TE.

Comparison of two different methods for lymphadenectomy along the left recurrent laryngeal nerve by minimally invasive esophagectomy in patients with esophageal squamous cell carcinoma: a prospective randomized trial

BACKGROUND

Lymph nodes along the left recurrent laryngeal nerve (LRLN) is thought to be highly involved in esophageal cancer. Given the unique anatomical positioning of the nerve, performing lymphadenectomy in this region requires advanced techniques within limited working space. Meanwhile, high incidence of morbidity and mortality is associated with lymphadenectomy. Although several methods have been applied to reduce the technical requirement and the incidence of postoperative complication, the optimal method remains controversial.

METHODS

This study was a single-center, prospective, randomized trial to investigate the utility of lymphadenectomy along the LRLN during the minimally invasive esophagectomy in esophageal squamous cell carcinoma patients by comparing the surgical outcome, postoperative complication, survival rate, and quality of life (QoL) between the retraction method (RM) and the suspension method (SM) in patients with esophageal cancer from June 2018 to November 2020. QoL was assessed according to questionnaire: EQ-5D-5L.

RESULTS

Of 94 patients were enrolled and randomized allocated to RM and SM group equally. Characteristics did not differ between groups. The duration of lymph node dissection along LRLN was significant longer in SM group ( P <0.001). No difference was observed about postoperative complications. One of in-hospital death was occurred in each group ( P >0.999). Patients in neither of groups exhibiting difference about 3-year disease-free survival rate ( P =0.180) and overall survival rate ( P =0.430). No difference was observed in postoperative QoL between groups at different time points (all, P >0.05).

CONCLUSION

Both methods of lymph node dissection along the LRLN during minimally invasive esophagectomy in esophageal squamous cell carcinoma patients are technically feasible and safe. The RM appears more favorable in terms of reducing surgical duration compared to the SM.

Side-overlap esophagogastric tube (SO-EG) reconstruction after minimally invasive Ivor Lewis esophagectomy or laparoscopic proximal gastrectomy for cancer of the esophagogastric junction

PURPOSE

Both laparoscopic proximal gastrectomy with lower esophagectomy (extended LPG) and minimally invasive Ivor Lewis esophagectomy (MIILE) are acceptable treatments for adenocarcinoma of the esophagogastric junction (AEG), but the optimal reconstruction technique for mediastinal esophagogastrostomy (one that provides adequate reflux prevention) has not been established. We devised a novel side-overlap esophagogastric-tube (SO-EG) reconstruction.

METHODS

We performed a retrospective review of patient records after LPG or MIILE. In each patient, we created a 3-cm wide gastric tube, overlapping the esophagus by 5 cm. A linear stapler was inserted into the left side of the esophageal stump and the anterior gastric wall along the greater curvature. The entry hole was closed to make a slit-like anastomosis, and the right side of the esophageal wall was fixed to the anterior gastric wall.

RESULTS

Ten consecutive patients underwent this procedure between June 2020 and July 2021. Five patients had Siewert type II AEG: 4 with lower thoracic esophageal cancer and 1 with benign lower esophageal stenosis. A total of 3 patients underwent extended LPG, and 7 underwent MIILE. The median operative time was 352 min (range, 221-556 min). The postoperative course was uneventful in 9 patients; a single patient developed pneumonia. Seven patients underwent follow-up endoscopy at 6 months. One patient with anastomotic stenosis and 2 with mild reflux esophagitis were treated conservatively.

CONCLUSION

Our novel SO-EG reconstruction is simple and feasible, with acceptable results for preventing reflux esophagitis. This technique can be performed with either extended LPG or MIILE.

Automated segmentation by deep learning of loose connective tissue fibers to define safe dissection planes in robot-assisted gastrectomy

The prediction of anatomical structures within the surgical field by artificial intelligence (AI) is expected to support surgeons’ experience and cognitive skills. We aimed to develop a deep-learning model to automatically segment loose connective tissue fibers (LCTFs) that define a safe dissection plane. The annotation was performed on video frames capturing a robot-assisted gastrectomy performed by trained surgeons. A deep-learning model based on U-net was developed to output segmentation results. Twenty randomly sampled frames were provided to evaluate model performance by comparing Recall and F1/Dice scores with a ground truth and with a two-item questionnaire on sensitivity and misrecognition that was completed by 20 surgeons. The model produced high Recall scores (mean 0.606, maximum 0.861). Mean F1/Dice scores reached 0.549 (range 0.335–0.691), showing acceptable spatial overlap of the objects. Surgeon evaluators gave a mean sensitivity score of 3.52 (with 88.0% assigning the highest score of 4; range 2.45–3.95). The mean misrecognition score was a low 0.14 (range 0–0.7), indicating very few acknowledged over-detection failures. Thus, AI can be trained to predict fine, difficult-to-discern anatomical structures at a level convincing to expert surgeons. This technology may help reduce adverse events by determining safe dissection planes.

Upper mediastinal lymph node dissection based on mesenteric excision in esophageal cancer surgery: confirmation by near-infrared image-guided lymphatic mapping and the impact on locoregional control

BACKGROUND

We previously reported a novel method of mesenteric excision for esophageal cancer surgery. The esophagus, trachea, recurrent laryngeal nerves (RLNs), and surrounding lymph nodes (LNs) are contained in a common mesenterium, which we termed the "mesotracheoesophagus". In addition, near-infrared (NIR) image-guided lymphatic mapping has recently been used. The purpose of this study was to confirm the feasibility of NIR image-guided lymphatic mapping for upper mediastinal LN dissection, and to confirm the oncological feasibility of our surgical approach.

METHODS

Fifteen patients with resectable esophageal cancer underwent submucosal injection of indocyanine green (ICG), and underwent robot-assisted esophagectomy. The frequency of ICG positivity in the LN basins along the RLNs, and metastatic frequency were assessed. Regarding the oncological feasibility of our thoracoscopic esophagectomy, the recurrence patterns and survival of 72 consecutive patients who underwent curative resection from 2011 to 2016 were analyzed.

RESULTS

ICG-positive LN basins along the right and left RLNs were found in 12 (80% of 15) patients (3 patients positive for metastatic LNs) and 11 (73% of 15) patients (2 positive for metastatic LNs and 1 false-negative), respectively. All ICG-positive LN basins were found within the mesotracheoesophagus. The sensitivity was 5/6 (83%), and the negative predictive value was 6/7 (86%). Among the 72 patients, with a median follow-up period of 1644 days, only 3 (4.2%) patients developed locoregional recurrence.

CONCLUSIONS

The NIR image-guided lymphatic mapping was feasible. Our results with no ICG-positive basins outside of the '"mesotracheoesophagus", supported our surgical approach. It might become standard, with acceptable locoregional control.

Risk factors for lymph node metastasis of the left recurrent laryngeal nerve in patients with esophageal squamous cell carcinoma

Background

The factors for left recurrent laryngeal nerve (RLN) lymph node (LN) metastasis have important guiding significance for whether the left RLN LNs should be dissected in patients with esophageal squamous cell carcinoma (ESCC), but few studies are currently available. To analyze the risk factors of LN metastasis of the left RLN area and to assess which LNs should be dissected in ESCC.

Methods

This was a retrospective study of patients who underwent McKeown minimally invasive esophagectomy (MIE) (no neoadjuvant therapy) at Tianjin Medical University Cancer Institute and Hospital (from January 2016 to December 2019). The detection of left RLN LNs using enhanced computed tomography (CT) was compared with the pathological examination.

Results

Of the total 94 participants, 43 had LN metastasis. The metastatic LNs were mainly located next to left (18.1%) and right (14.9%) RLN, and the left gastric artery (13.8%). Tumor size, LN size, tumor invasion (T stage), N stage, and tumor node metastasis (TNM) stage were associated with left RLN LNs metastasis, while LN size was the only independently associated factor [odds ratio (OR) =1.569, 95% confidence interval (CI): 0.259–1.956, P=0.0012]. The area under receiver operating characteristic (ROC) curve (AUC) reached 0.877, with 64% sensitivity and 75% specificity using a cutoff of 5.5 mm LN size.

Conclusions

The size of left RLN LN is independently associated with metastasis. Left RLN LNs >5.5 mm at CT examination are more likely to be positive and should probably be dissected.

Initial introduction of robot-assisted, minimally invasive esophagectomy using the microanatomy-based concept in the upper mediastinum

Background

We have recently standardized upper mediastinal lymph node dissection (UMLND) using a microanatomy-based concept in thoracoscopic esophagectomy in the prone position (TEPP), and introduced robot-assisted minimally invasive esophagectomy (RAMIE) using the same concept as in TEPP while aiming at solo surgery. The purpose of this study was to investigate the outcomes of RAMIE using the microanatomy-based concept in the initial introduction phase.

Methods

We have performed more than 500 TEPP procedures as minimally invasive esophagectomy (MIE). After performing about 400 cases of MIE, we established a microanatomy-based standardization of UMLND. In October 2018, we introduced RAMIE, and have performed 75 procedures in 20 months. Two groups were analyzed: a group after microanatomy-based standardization in TEPP (100 cases after completing 400 cases of TEPP) and a RAMIE group (75 cases). Finally, 51 paired cases were matched using a propensity score. Furthermore, the change in postoperative short-term outcome for RAMIE in the initial introduction phase was analyzed.

Results

Although there were no significant differences between the two groups in the number of upper mediastinal lymph nodes dissected, there was a significant decrease (P = 0.036) in intraoperative blood loss volume with RAMIE, representing a definite benefit for patients. The thoracoscopic operative time for RAMIE decreased by almost 100 min following less than 50 cases of experience, reaching the same level as that for recent TEPP, but with only one-tenth the operator experience. There were no significant differences in the total postoperative morbidity rate including the recurrent laryngeal nerve palsy rate.

Conclusion

RAMIE has been introduced safely and smoothly using the microanatomy-based concept established in TEPP.

Microanatomy-based standardization of left upper mediastinal lymph node dissection in thoracoscopic esophagectomy in the prone position

BACKGROUND

Although thoracoscopic esophagectomy in the prone position (TEPP) has become a standard procedure for esophageal cancer surgery, upper mediastinal lymph node dissection (UMLND) on the left side remains an issue. We have recently developed a new standardized approach to left UMLND in TEPP based on the microanatomy of the membranes and layers with the aim of achieving quick and safe surgery. The purpose of this study was to establish and evaluate our new standardized procedure in left UMLND.

PATIENTS AND METHODS

Patients were divided into 2 groups: a pre-standardization group (n = 100) and a post-standardization group (n = 100). Eventually, 83 paired cases were matched using propensity score matching. In our new standardized procedure, left UMLND was performed while focusing on the visceral sheath, vascular sheath, and the fusion layer between them using a magnified view.

RESULTS

The thoracoscopic operative time was significantly shorter (P < 0.001) in the post-standardization group [n = 83; 209.0 (176.0-235.0) min] than in the pre-standardization group [n = 83; 235.5 (202.8-264.5) min]. No significant differences were found in the number of mediastinal lymph nodes dissected or intraoperative blood loss between the two groups. There was a tendency for the total postoperative morbidity to decrease in the post-standardization group. Furthermore, the left recurrent laryngeal nerve palsy rate was significantly lower in the post-standardization group (18.1% to 8.7%, P = 0.015).

CONCLUSION

Microanatomy-based standardization contributes to safe and efficient left UMLND.