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

Performing robot-assisted minimally invasive esophagectomy for patients with a narrow mediastinum and left-shifted esophagus for esophageal squamous cell carcinoma presents further challenges

BACKGROUND

Several studies have compared robot-assisted minimally invasive esophagectomy (RAMIE) with conventional minimally invasive surgery (C-MIE). However, the anatomical factors that may make certain patients more suitable for RAMIE remains unclear. This study compared the surgical outcomes of RAMIE with those of C-MIE in patients with narrow mediastinum and left-shifted esophagus.

METHODS

Between January 2017 and December 2023, 260 patients with esophageal squamous cell carcinoma (ESCC) who underwent MIE (C-MIE or RAMIE) at Kobe University Hospital were included in the study. We developed a new index to assess the narrow mediastinum and left-shifted esophagus at the tracheal bifurcation level using computed tomography imaging. Cox proportional hazards regression analyses were performed to identify the prognostic factors.

RESULTS

Patients with a narrow mediastinum and left-shifted esophagus had a higher incidence of recurrent laryngeal nerve (RLN) palsy and fewer lymph nodes dissections than other patients (p = 0.026 and p = 0.051, respectively). In the entire cohort, the operative time in the RAMIE group was longer than that in the C-MIE group (< 0.0001). No significant differences in other variables, including RLN palsy, were observed between the two groups. Among patients with narrow mediastinum and left-shifted esophagus, RAMIE was associated with longer operative time and fewer lymph nodes dissected from the left and right sides of the upper mediastinum compared to C-MIE (p < 0.0001, 0.0001, and 0.0001, respectively). Regarding the RLN palsy, there was no significant difference (p = 0.79).

CONCLUSIONS

There are challenges in performing RAMIE in patients with a narrow mediastinal and left-shifted esophagus. Therefore, establishing an effective procedure for these patients is important.

Risk factors of poor long-term outcomes in elderly patients with esophageal squamous cell carcinoma after minimally invasive esophagectomy

PURPOSE

Elderly patients with esophageal squamous cell carcinoma (ESCC) have more comorbidities than young patients do. Elderly smokers have a high mortality rate owing to physical dysfunction. This study aimed to identify risk factors for long-term outcomes after minimally invasive esophagectomy (MIE) in elderly patients with ESCC.

METHODS

This study included 110 elderly patients (aged ≥ 75 years) with ESCC who underwent MIE at Kobe University Hospital. Multivariate Cox proportional hazards regression analyses were performed to identify risk factors, including the geriatric nutritional risk index (GNRI), Charlson comorbidity index, and elderly smoker status, defined as smoking at the age of 70 years.

RESULTS

Multivariate analysis identified that elderly smokers, cT or cN status (≥ cT2 or cN-positive), and GNRI (≤ 92) were independent prognostic factors for overall survival (p = 0.026, 0.019, and 0.038, respectively). For patients with ≥ cT2 or cN-positive ESCC, elderly smokers or patients with GNRI (≤ 92) have significantly worse survival (p = 0.038). Elderly smokers were at risk of death from other diseases five years postoperatively (p = 0.016).

CONCLUSIONS

Elderly smokers, cT2 or cN positivity, and low GNRI were risk factors for poor survival. Furthermore, for patients with ≥ cT2 or cN-positive ESCC, these risk factors were associated with poor survival.

Oncological outcomes of thoracic duct preservation and resection for esophageal carcinoma based on an understanding of its surgical microanatomy in the era of minimally invasive esophagectomy and neoadjuvant chemotherapy

BACKGROUND

Although the oncological benefits of thoracic duct (TD) resection have been reported, recent research has questioned its impact on survival. With advancements in minimally invasive esophagectomy (MIE) and a deeper understanding of the microanatomy, standardizing techniques for TD resection/preservation have become increasingly important. We demonstrated a minimally invasive surgical procedure for esophagectomy, with and without TD resection, in patients who received neoadjuvant chemotherapy.

METHODS

This multicenter, retrospective cohort study evaluated patients with cT1-3 thoracic esophageal cancer who underwent thoracoscopic McKeown esophagectomy after neoadjuvant chemotherapy at two Japanese cancer centers between 2012 and 2019. The effects of TD preservation and resection were compared using propensity score-matching. Short- and long-term outcomes were analyzed.

RESULTS

We showed the standard procedure for TD resection and preservation and demonstrated that recognizing membrane structures is crucial for precise resection of the esophagus and regional lymph nodes. After matching, 255 patients in each group were analyzed. The TD resection group showed no significant differences in short-term outcomes, complication rates, or thoracic lymph node harvest compared to the TD preservation group. Both groups had similar 5-year overall and recurrence-free survival rates, with no significant differences in recurrence patterns.

CONCLUSIONS

In the context of modern esophageal carcinoma treatment, in which MIE and neoadjuvant chemotherapy are standard practices, the impact of TD resection on prognosis is limited. Recognizing membrane structures is crucial for accurate esophagectomy using the MIE approach.

Robotic esophagectomy with function-preserving radical mediastinal lymphadenectomy for esophageal cancer

Radical lymphadenectomy is the critical component of surgery for esophageal cancer. However, lymphadenectomy significantly contributes to postoperative morbidity, particularly in terms of pulmonary complications following esophagectomy. Function-preserving mediastinal lymphadenectomy seeks to balance the procedure's necessary radicality and optimal functional outcomes. This approach emphasizes the preservation of the thoracic duct, tracheobronchial vascularity, and the pulmonary and recurrent laryngeal branches of the vagus nerve. Preservation of the thoracic duct is facilitated by indocyanine green fluorescence. Compared to the conventional technique of thoracic duct identification using anatomical landmarks, indocyanine green fluorescence lymphangiography offers real-time feedback, making it particularly advantageous in cases with complex anatomy or when the thoracic duct is challenging to visualize using conventional methods. Preservation of pulmonary branches of the right vagus during subcarinal lymphadenectomy and left recurrent laryngeal nerve during left paratracheal node dissection are technically challenging. The description of two types of left recurrent laryngeal nerve node dissection and technical tips for nerve function preservation are outlined in this review. Intraoperative neuromonitoring is a useful adjunct for nerve-sparing mediastinal lymphadenectomy. As ischemia to the respiratory tract impairs respiratory protective mechanisms, preservation of the tracheobronchial blood supply is critical. Preoperative imaging to detect bronchial artery anatomical variations and intraoperative assessment of perfusion using laser doppler flowmetry and indocyanine green fluorescence angiography are useful strategies to minimize tracheobronchial ischemia. Function-preserving mediastinal lymphadenectomy has the potential to improve short- and long-term outcomes after esophagectomy for esophageal cancer.

The totally mechanical Collard technique for cervical esophagogastric anastomosis reduces anastomotic stricture compared with triangular anastomosis in minimally invasive esophagectomy with gastric conduit reconstruction through the retrosternal route: a propensity score-matched study

BACKGROUND

Cervical esophagogastric anastomosis is conventionally performed using the McKeown esophagectomy. However, an optimal anastomotic technique has not yet been established. This study aimed to compare the clinical outcomes of triangular anastomosis (TA) and totally mechanical Collard anastomosis (TMCA) for cervical esophagogastric anastomosis during minimally invasive esophagectomy with gastric conduit reconstruction through the retrosternal route.

METHODS

In this matched- cohort study, 117 patients who underwent minimally invasive esophagectomy between 2019 and 2024 were divided into TA and TMCA groups. The TA technique was performed between September 2019 and December 2021, and the TMCA technique was performed between January 2022 and January 2024. We then compared the surgical outcomes and postoperative complications (pneumonia, recurrent laryngeal nerve palsy, anastomotic leakage, and stricture) between the two groups.

RESULTS

Propensity score matching revealed that 40 patients were included in both the TA and TMCA groups. The rates of pneumonia, recurrent laryngeal nerve palsy, and anastomotic leakage were not significantly different between the two groups. However, the rate of anastomotic stricture was lower in the TMCA than in the TA group (2.5% vs. 27.5%, respectively, P = 0.003).

CONCLUSIONS

Compared with the TA technique, the TMCA technique reduced the rate of anastomotic stricture when performing cervical esophagogastric anastomosis during minimally invasive esophagectomy with gastric conduit reconstruction through the retrosternal route.

The number of resected lymph nodes from the upper mediastinal area predicts long-term outcomes of esophageal squamous cell carcinoma after minimally invasive esophagectomy

BACKGROUND

The total number of resected lymph nodes (LNs) is an important determinant of longer survival after esophagectomy for esophageal squamous cell carcinoma (ESCC). However, the resected LN counts from areas that affect long-term outcomes remain unclear.

METHODS

This study included 406 patients who underwent minimally invasive esophagectomies (MIEs) at Kobe University Hospital. Resected LN counts were evaluated in the following areas: upper mediastinal (UM), middle mediastinal (MM), lower mediastinal (LM), and abdominal (Abd). Cut-off values for LN counts from each area were determined using receiver operating characteristics analysis of the survival status. Cox proportional hazards regression analyses were performed to identify prognostic factors.

RESULTS

The cut-off values for large or small numbers of resected LN counts in the UM, MM, LM, and Abd areas were 4, 8, 5, and 18, respectively, in patients with upper and middle thoracic (Ut/Mt) ESCC and 7, 6, 5, and 24, respectively, in patients with lower thoracic (Lt) ESCC. Multivariate analysis in patients with Ut/Mt ESCC revealed that tumor invasion depth, LN metastasis, and the resected LN count from the UM area were independent risk factors for overall survival [hazard ratio (HR), 7.04; 95% confidence interval (CI) 4.47-11.1; HR, 4.01; 95% CI 1.96-8.21; HR, 2.18; 95% CI 1.24-3.82, respectively]. In patients with Lt ESCC, tumor invasion depth, LN metastasis, and pulmonary complications were independent risk factors for overall survival (HR, 4.23; 95% CI 2.14-8.35; HR, 3.83; 95% CI 1.75-8.38; HR, 2.80; 95% CI 1.38-5.65, respectively). Resected LN counts from no areas were prognostic factors.

CONCLUSION

The number of resected LNs from the UM area influenced the survival outcomes of patients with Ut/Mt ESCC after MIE.

Impact of Tumor Size on Survival Outcome in Esophageal Squamous Cell Carcinoma After Esophagectomy Following Neoadjuvant Chemotherapy

BACKGROUND

Large tumor size is a prognostic factor in esophageal squamous cell carcinoma (ESCC). However, the effect of tumor size on outcomes following neoadjuvant chemotherapy (NAC) has not been evaluated. This study aimed to assess the influence of tumor size on prognosis of patients undergoing esophagectomy after NAC.

PATIENTS AND METHODS

This study was made up of 272 patients who underwent esophagectomy after NAC at Kobe University Hospital. We evaluated the pathological tumor size and determined the cutoff level for tumor size using receiver operating characteristics analysis to the survival status. Cox proportional hazards regression analyses were performed to identify prognostic factors.

RESULTS

The patients were categorized into two groups: patients with tumor sizes ≥ 36 mm and < 36 mm. Deep pathological tumor invasion and worse histological response to NAC were associated with tumor size ≥ 36 mm. In patients with pT0-1, pT2, and pT4 ESCC, no significant differences in overall survival (OS) rates were observed between the two groups. In patients with pT3, OS of the tumor size ≥ 36 mm group was significantly worse than that of the tumor size < 36 mm group (p < 0.0001). Multivariate analysis in pT3 patients revealed tumor size ≥ 36 mm was an independent risk factor for OS. The 5-year OS rate was 10% in patients with tumor size ≥ 36 mm pT3 ESCC with pathological lymph node metastasis (p < 0.0001).

CONCLUSIONS

Tumor size ≥ 36 mm is an independent risk factor for poorer survival in pT3 patients. Furthermore, tumor size ≥ 36 mm with pathological lymph node metastasis in pT3 patients was associated with very poor survival.

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.

Efficacy and Postoperative Outcomes of Laparoscopic Retrosternal Route Creation for the Gastric Conduit: Propensity Score-Matched Comparison to Posterior Mediastinal Reconstruction

BACKGROUND

Retrosternal reconstruction has lower risks for severe postoperative morbidities, such as gastro-tracheal fistula or esophageal hiatal hernia. We have previously reported the laparoscopic retrosternal route creation (LRRC) method, but its safety and efficacy remain unclear.

METHODS

In total, 374 patients with esophageal carcinoma who underwent minimally invasive McKeown esophagectomy in the prone position between 2010 and 2021 were retrospectively reviewed. We performed a propensity score-matched analysis with the simple, nearest-neighbor method and no calipers to compare postoperative outcomes and reconstructed gastric conduit functionality between patients who underwent LRRC and counterparts who underwent posterior mediastinal reconstruction.

RESULTS

After matching, 62 patients were included in the laparoscopic retrosternal group (LR group) or posterior mediastinal group (PM group). No significant differences were observed between the groups, apart from the number of robot-assisted surgeries, the extent of lymph node dissection, and the method of cervical anastomosis. There were no significant differences in the incidence of Clavien-Dindo grade ≥ 2 complications. Gastro-tracheal fistula (n = 1) and esophageal hiatal hernia (n = 2) occurred in the PM group but not in the LR group. There were no differences in the incidence of pulmonary embolism between the groups (5% vs. 5%). The postoperative anastomotic stenosis rate was similar (16% vs. 27%, p = 0.192). Endoscopic findings of reflux esophagitis (modified Los Angeles classification ≥ M) at 1 year after surgery were significantly better in the LR group (p = 0.037).

CONCLUSIONS

LRRC for gastric conduit reconstruction is safe and valuable. It is associated with good reconstructed gastric conduit function.

Robot-assisted minimally invasive esophagectomy versus video-assisted minimally invasive esophagectomy: a systematic review and meta-analysis

Background

Robot-assisted minimally invasive esophagectomy (RAMIE) has been demonstrated to offer realistic three-dimensional visual clarity, flexible movement and so on. The high cost is the main reason hampering universal application. The aim of this study was to compare the short-term outcomes of RAMIE versus video-assisted minimally invasive esophagectomy (VAMIE).

Methods

The PubMed, EMBASE and Web of Science databases were systematically searched up to June 1, 2021, for studies comparing RAMIE and VAMIE.

Results

Nineteen studies were enrolled, which consisted of a total of 4,714 patients, including 2,306 patients in the RAMIE group and 2,408 patients in the VAMIE group. In RAMIE patients, higher numbers of total lymph nodes (MD =0.171, 95% CI: 0.086–0.255, P<0.001) and lymph nodes along the left recurrent laryngeal nerve (RLN) (MD =0.219, 95% CI: 0.097–0.340, P<0.001) were removed. In RAMIE patients in the McKown group, higher numbers of total lymph nodes (MD =0.173, 95% CI: 0.080–0.265, P<0.001) and lymph nodes along the left RLN (MD =0.220, 95% CI: 0.090–0.350, P=0.001) were removed, while in those in the ESCC group, higher numbers of total lymph nodes (MD =0.249, 95% CI: 0.091–0.407, P=0.002) and lymph nodes along the left RLN (MD =0.239, 95% CI: 0.102–0.377, P=0.001) were removed.

Discussion

This study indicated that the main advantage of RAMIE was a greater number of harvested lymph nodes, which may be beneficial to diagnosis and local control. RCTs with larger sample sizes and studies reporting long-term outcomes are needed to evaluate the advantages and disadvantages of RAMIE and VAMIE.

Incidence of Recurrent Laryngeal Nerve Palsy in Robot-Assisted Versus Conventional Minimally Invasive McKeown Esophagectomy in Prone Position: A Propensity Score-Matched Study

BACKGROUND

Esophagectomy with lymphadenectomy is the principal treatment for localized esophageal cancer. Conventional minimally invasive esophagectomy (C-MIE) in prone position has spread worldwide as it is less invasive. However, its efficacy remains controversial. Robot-assisted MIE (RAMIE) can have more advantages than C-MIE. Therefore, the current study aimed to validate whether RAMIE is associated with lower incidence of left recurrent laryngeal nerve (RLN) palsy compared with C-MIE in prone position.

PATIENTS AND METHODS

In total, 404 patients with esophageal carcinoma underwent MIE (353 C-MIEs and 51 RAMIEs) in prone position at Kobe University between 2010 and 2020. Then, propensity score matching was performed, and results showed that 51 patients should be included in each group. Thereafter, the perioperative outcomes between the two groups were compared.

RESULTS

The RAMIE group had a significantly longer operative time than the C-MIE group (P < 0.0001). However, the number of lymph nodes resected along the left RLN was similar in both groups. Moreover, the incidence of left RLN palsy was significantly lower in the RAMIE group than in the C-MIE [Clavien-Dindo classification grade II; 0 (0%) versus 32 (9%), P = 0.022 in entire cohort, and 0 (0%) versus 5 (10%), P = 0.022 in matched cohort. Esophagectomy Complications Consensus Group definitions type I; 8 (16%) versus 101 (29%), P = 0.041 in entire cohort and 8 (16%) versus 18 (35%) in matched cohort, P = 0.023].

CONCLUSION

RAMIE is superior to C-MIE in prone position in decreasing the incidence of left RLN palsy.