Technique and surgical outcomes of mesenterization and intra-operative neural monitoring to reduce recurrent laryngeal nerve paralysis after thoracoscopic esophagectomy: A cohort study

Effectiveness of recurrent laryngeal nerve monitoring on nerve paralysis during open McKeown esophagectomy: a prospective, cohort study

BACKGROUND

Recurrent laryngeal nerve paralysis (RLNP) is a critical postoperative complication in esophagectomy. Intraoperative nerve monitoring (IONM) is a technique that can be used in high-risk surgeries to prevent, identify, and mitigate nerve damage. In this prospective study, we evaluated the feasibility and effectiveness of IONM in open McKeown esophagectomy for esophageal cancer.

METHODS

From December 2020 to September 2023, 88 patients diagnosed with esophageal cancer were enrolled to receive IONM for open McKeown esophagectomy at Cancer Center, Sun Yat-sen University. The primary outcome was the incidence of RLNP after extubation. The secondary outcomes were postoperative complications, number of dissected lymph nodes, length of hospital stay, ICU duration and number of deaths.

RESULTS

A total of 83 patients were included in the final analysis. The incidence of RLNP after extubation was 30.1%. The occurrence of postoperative pulmonary complications was 20.5%. The median hospital stays were 13 days. The incidence of anastomotic leakage was 13.3%. No in-hospital deaths were reported. Postoperative RLNP prolonged the length of hospital stay (P = 0.042).

CONCLUSION

Our findings indicated that IONM could potentially be associated with a possible reduction in RLNP incidence following open McKeown esophagectomy for esophageal cancer. However, future research including well-designed randomized controlled trials may be beneficial to clarify these preliminary results.

TRIAL REGISTRATION NUMBER

ChiCTR2000029687 https://www.chictr.org.cn/showproj.html?proj=49103.

Optimal extent of left recurrent laryngeal nerve para-lymph node dissection in esophageal squamous cell carcinoma: a retrospective analysis based on cytokeratin 19 immunopositivity for micrometastasis detection

No consensus has been achieved for the optimal extent of left recurrent laryngeal nerve para-lymph node dissection (LRLN-LND) for esophageal squamous cell carcinoma (ESCC). Surgeons follow different extents according to their experience, technical proficiency, and habits. Immunohistochemical (IHC) analysis is a feasible method to detect micrometastasis (MM) of lymph nodes in ESCC. We hereby explored the optimal extent of LRLN-LND by detecting the routine pathological and MM-positive rates of lymph nodes in different regions. We retrospectively reviewed patients who underwent R0 resection and LRLN-LND between September 2018 and July 2019. We divided lymph nodes into four groups based on the LRLN and cervicothoracic junction plane: (i) anterior LRLN region above the plane, (ii) posterior LRLN region above the plane, (iii) anterior LRLN region under the plane, and (iv) posterior LRLN region the plane. In total, 263 lymph nodes were collected from 52 patients. We detected MM based on cytokeratin 19 (CK19) immunopositivity in lymph nodes with negative histological detection. We calculated the positive rates of routine pathological and MM detection and analyzed the metastasis status in different regions. Lymph nodes of cervical regions (group 1 and group 2), which are always ignored due to inherent technical difficulties and poor exposure, showed higher positive rates than those in group 4; the rate in group 3 was also higher than that in group 4. Routine histological detection achieved positive rates of 8.9, 6.7, 1.6, and 0.9%, respectively. After the detection of MM by the CK19 IHC method, increased positive rates were achieved. To the best of our knowledge, only a few studies have focused on the optimal extent of LRLN-LND. Because of the high positive rates both in routine pathological detection and by CK19 IHC MM detection in this study, thorough LRLN-LND during esophagectomy for ESCC is necessary, including the cervical region and anterior nerve region adjacent to the trachea.

Impact of intraoperative recurrent laryngeal nerve monitoring on minimally invasive esophagectomy outcomes for esophageal cancer: a meta-analysis of case-control studies

Esophagectomy and lymphadenectomy for esophageal cancer carry an inherent risk of recurrent laryngeal nerve (RLN) injury. Intraoperative nerve monitoring (IONM) may help prevent RLN damage, though evidence on its effectiveness is still limited. This systematic review and meta-analysis (SRMA) evaluate the feasibility and efficacy of IONM during minimally invasive esophagectomy (MIE) for esophageal cancer. This SRMA followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines, with a registered protocol on PROSPERO (CRD42022367916). Two independent authors conducted a comprehensive literature search across multiple databases, screening studies on MIE for esophageal cancer using IONM. Case-control studies were included, focusing on the RLN palsy (RLNP) rate as the primary outcome. A total of 11 studies involving 1907 patients (IONM group: 752 patients; non-IONM group: 1155 patients) were included in the SRMA. IONM significantly reduced the incidence of RLNP (OR = 0.47, P < 0.001). Length of hospital stay (LOHS) and lower respiratory tract infection (LRTI) rates were significantly reduced with IONM use. No significant differences were observed in anastomotic leak, chylothorax, total number of lymph nodes dissected, operation time, aspiration rates, or intraoperative blood loss. The pooled sensitivity and specificity of IONM for detecting RLN injury were 83.3% and 81%, respectively. IONM during MIE significantly reduces the incidence of RLNP, postoperative LRTI, and shortens the LOHS, without adding operative risks. Further research is needed to evaluate its long-term survival benefits and cost-effectiveness.

Intraoperative Recurrent Laryngeal Nerve Monitoring for Esophagectomy: A National Cohort Study

BACKGROUND

Lymphadenectomy around the recurrent laryngeal nerve (RLN) is an essential part of curative surgery for esophageal cancer. Although several single-center studies have shown that intraoperative nerve monitoring (IONM) can avoid RLN palsy, this has not been confirmed in a large-scale multicenter study. This study used a national database to evaluate whether IONM can reduce postoperative RLN palsy during minimally invasive esophagectomy (MIE) for esophageal cancer.

METHODS

We retrieved data of patients with esophageal cancer who underwent 3-field thoracoscopic or robotic MIE with cervical anastomosis with IONM(+) (502 patients) and without IONM(-) (4353 patients) from April 2020 to March 2022 from the Diagnosis Procedure Combination database in Japan. We used propensity score-matching analysis to compare the frequency of postoperative RLN palsy and respiratory complications between the IONM(+) group and IONM(-) group.

RESULTS

The postoperative RLN palsy rate was significantly lower in the IONM(+) than IONM(-) group (odds ratio, 0.24; 95% CI, 0.13-0.46). The respiratory complication rate was also significantly lower in the IONM(+) than in the IONM(-) group (odds ratio, 0.66; 95% CI, 0.45-0.97). The anesthesia time was significantly longer in the IONM(+) group (regression coefficient, 60.1 minutes; 95% CI, 44.2-76.9 minutes). The length of postoperative hospitalization tended to be shorter in the IONM(+) than in the IONM(-) group (regression coefficient, -1.39 days; 95% CI, -3.91 to 1.14).

CONCLUSIONS

This national cohort study showed that IONM during 3-field MIE for esophageal cancer was associated with a reduction of postoperative RLN palsy and respiratory complications.

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.

Assessment of pre-extubating recurrent laryngeal nerve palsy using ultrasound in postoperative patients with esophageal cancer: a prospective observational study

PURPOSE

Ultrasound performed after extubation has been suggested to be useful for the diagnosis of recurrent laryngeal nerve (RLN) paralysis. However, the use of ultrasound for this purpose before extubation has not been examined. The aim of this study was to examine the versatility (interrater reliability) and usefulness of ultrasound for evaluating the movement of vocal cords before extubation.

METHODS

The subjects were 30 patients who underwent radical surgery for esophageal cancer from August 2020 to December 2021. An experienced examiner performed an ultrasound examination before and after elective extubation on the day after surgery to evaluate RLN paralysis and record videos. Bronchoscopy was then performed to make a definite diagnosis. Three anesthetists blinded to the diagnosis also evaluated the cases using the videos, and the versatility of the examination was determined using a kappa test.

RESULTS

The diagnostic accuracies of the examiner and three anesthetists were 76.7%, 50.0%, 53.3%, and 46.7%, respectively, and the kappa coefficients for the examiner with the anesthetists were 0.310, 0.502, and 0.169, respectively. The sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of RLN paralysis by the examiner using ultrasound before extubation were 0.57, 0.95, 0.80, and 0.87, respectively.

CONCLUSION

These results indicate a lack of versatility of the ultrasound examination based on the low kappa coefficients. However, with an experienced examiner, ultrasound can serve as a non-invasive examination that can be performed before extubation with high accuracy and specificity for diagnosis of postoperative RLN paralysis.

Recurrent Laryngeal Nerve Intraoperative Neuromonitoring Indications in Non-Thyroid and Non-Parathyroid Surgery

Introperative nerve monitoring (IONM) of the recurrent laryngeal nerve (RLN) is a well-established technique to aid in thyroid/parathyroid surgery. However, there is little evidence to support its use in non-thyroid or non-parathyroid surgery. The aim of this paper was to review the current evidence regarding the use of IONM in non-thyroid/non-parathyroid surgery in the head and neck and thorax. A literature search was performed from their inception up to January 2024, including the term "recurrent laryngeal nerve monitoring". IONM in non-thyroid/non-parathyroid surgery has mainly been previously described in oesophageal surgery and in tracheal resections. However, there is little published evidence on the role of IONM with other resections in the vicinity of the RLN. Current evidence is low-level for the use of RLN IONM in non-thyroid/non-parathyroid surgery. However, clinicians should consider its use in surgery for pathologies where the RLN is exposed and could be injured.

Intraoperative Nerve Monitoring during Minimally Invasive Esophagectomy and 3-Field Lymphadenectomy: Safety, Efficacy, and Feasibility

Background

The objective of this study was to demonstrate the safety, efficacy, and feasibility of intraoperative monitoring of the recurrent laryngeal nerves during thoracoscopic and robotic 3-field esophagectomy.

Methods

This retrospective analysis details our initial experience using intraoperative nerve monitoring (IONM) during minimally invasive 3-field esophagectomy. Data were obtained from a prospectively maintained database and electronic medical records. The study included all patients who underwent minimally invasive (video-assisted thoracic surgery/robotic) transthoracic esophagectomy with neck anastomosis. The patients were divided into those who underwent IONM during the study period and a historical cohort who underwent 3-field esophagectomy without IONM at the same institution. Appropriate statistical tests were used to compare the 2 groups.

Results

Twenty-four patients underwent nerve monitoring during minimally invasive 3-field esophagectomy. Of these, 15 patients underwent thoraco-laparoscopic operation, while 9 received a robot-assisted procedure. In the immediate postoperative period, 8 of 24 patients (33.3%) experienced vocal cord paralysis. Relative to a historical cohort from the same institution, who were treated with surgery without nerve monitoring in the preceding 5 years, a 26% reduction was observed in the nerve paralysis rate (p=0.08). On follow-up, 6 of the 8 patients with vocal cord paralysis reported a return to normal vocal function. Additionally, patients who underwent IONM exhibited a higher nodal yield and a decreased frequency of tracheostomy and bronchoscopy.

Conclusion

The use of IONM during minimally invasive 3-field esophagectomy is safe and feasible. This technique has the potential to decrease the incidence of recurrent nerve palsy and increase nodal yield.

Application of Intraoperative Neuromonitoring (IONM) of the Recurrent Laryngeal Nerve during Esophagectomy: A Systematic Review and Meta-Analysis

BACKGROUND

recurrent laryngeal nerve palsy (RLNP) is a common and severe complication of esophagectomy in esophageal cancer (EC). Several studies explored the application of intraoperative neuromonitoring (IONM) in esophagectomy to prevent RLNP. The purpose of this study was to conduct a systematic review and meta-analysis to evaluate the value of IONM in esophagectomy for EC.

METHODS

an electronic of the literature using Google Scholar, PubMed, Embase, and Web of Science (data up to October 2022) was conducted and screened to compare IONM-assisted and conventional non-IONM-assisted esophagectomy. RLNP, the number of mediastinal lymph nodes (LN) dissected, aspiration, pneumonia, chylothorax, anastomotic leakage, the number of total LN dissected, postoperative hospital stay and total operation time were evaluated using Review Manager 5.4.1.

RESULT

ten studies were ultimately included, with a total of 949 patients from one randomized controlled trial and nine retrospective case-control studies in the meta-analysis. The present study demonstrated that IONM reduced the incidence of RLNP(Odds Ratio (OR) 0.37, 95% Confidence Interval (CI) 0.26-0.52) and pneumonia (OR 0.58, 95%CI 0.41-0.82) and was associated with more mediastinal LN dissected (Weighted Mean Difference (WMD) 4.75, 95%CI 3.02-6.48) and total mediastinal LN dissected (WMD 5.47, 95%CI 0.39-10.56). In addition, IONM does not increase the incidence of aspiration (OR 0.4, 95%CI 0.07-2.51), chylothorax (OR 0.55, 95%CI 0.17-1.76), and anastomotic leakage (OR 0.78, 95%CI 0.48-1.27) and does not increase the total operative time (WMD -12.33, 95%CI -33.94-9.28) or postoperative hospital stay (WMD -2.07 95%CI -6.61-2.46) after esophagectomy.

CONCLUSION

IONM showed advantages for preventing RLNP and pneumonia and was associated with more mediastinal and total LN dissected in esophagectomy. IONM should be recommended for esophagectomy.

Continuous Recurrent Laryngeal Nerve Monitoring During Single-Port Mediastinoscopic Radical Esophagectomy for Esophageal Cancer

BACKGROUND

Although single-port mediastinoscopic radical esophagectomy is ultimate minimally invasive surgery for esophageal cancer without thoracotomy or the thoracoscopic approach, the high incidence of recurrent laryngeal nerve (RLN) palsy remains a pivotal clinical issue.

METHODS

This study included 41 patients who underwent single-port mediastinoscopic radical esophagectomy with mediastinal lymphadenectomy between September 2014 and March 2022. Among these, continuous nerve monitoring (CNM) for RLN was done in 25 patients (CNM group), while the remaining 16 patients underwent without CNM (non-CNM group). Clinical benefits of CNM for RLN were evaluated.

RESULTS

The overall incidence of postoperative RLN palsy was 14.6% (6/41). The CNM group showed a significantly lower incidence of postoperative RLN palsy as compared to the non-CNM group (P = 0.026: CNM vs. non-CRNM: 4.0% (1/25) vs. 31.2% (5/16)). The CNM group had a lower incidence of postoperative pneumoniae (CNM vs. non-CNM: 4.0% (1/25) vs. 18.8% (3/16)) and shorter days of postoperative hospital stay (CNM vs. non-CNM: 13 days vs. 41 days). Multivariate analysis revealed that the CNM use (odds ratio 0.07; 95% CI 0.05-0.98) was an independent factor avoiding postoperative RLN palsy.

CONCLUSION

The CNM for RLN contributes to a remarkable reduction in the risk of postoperative RLN palsy and improvement in outcomes in single-port mediastinoscopic radical esophagectomy.

Real-time detection of the recurrent laryngeal nerve in thoracoscopic esophagectomy using artificial intelligence

BACKGROUND

Artificial intelligence (AI) has been largely investigated in the field of surgery, particularly in quality assurance. However, AI-guided navigation during surgery has not yet been put into practice because a sufficient level of performance has not been reached. We aimed to develop deep learning-based AI image processing software to identify the location of the recurrent laryngeal nerve during thoracoscopic esophagectomy and determine whether the incidence of recurrent laryngeal nerve paralysis is reduced using this software.

METHODS

More than 3000 images extracted from 20 thoracoscopic esophagectomy videos and 40 images extracted from 8 thoracoscopic esophagectomy videos were annotated for identification of the recurrent laryngeal nerve. The Dice coefficient was used to assess the detection performance of the model and that of surgeons (specialized esophageal surgeons and certified general gastrointestinal surgeons). The performance was compared using a test set.

RESULTS

The average Dice coefficient of the AI model was 0.58. This was not significantly different from the Dice coefficient of the group of specialized esophageal surgeons (P = 0.26); however, it was significantly higher than that of the group of certified general gastrointestinal surgeons (P = 0.019).

CONCLUSIONS

Our software's performance in identification of the recurrent laryngeal nerve was superior to that of general surgeons and almost reached that of specialized surgeons. Our software provides real-time identification and will be useful for thoracoscopic esophagectomy after further developments.

Application of intraoperative nerve monitoring for recurrent laryngeal nerves in minimally invasive McKeown esophagectomy

BACKGROUND

Mediastinal lymphadenectomy is of great importance during esophagectomy for esophageal squamous cell carcinoma. However, recurrent laryngeal nerve (RLN) injury is a severe complication caused by lymphadenectomy along the RLN. Intraoperative nerve monitoring (IONM) can effectively identify the RLN and reduce the incidence of postoperative vocal cord paralysis (VCP). Here, we describe the feasibility and effectiveness of IONM in minimally invasive McKeown esophagectomy.

METHODS

A total of 150 patients who underwent minimally invasive McKeown esophagectomy from 2016 to 2020 were enrolled in this study. We divided the patients into two groups: a neuromonitoring group (IONM, n = 70) and a control group (control, n = 80). Clinical data, surgical variables, and postoperative complications were retrospectively analyzed and compared.

RESULTS

There was no significant difference in baseline data between the two groups. Postoperative VCP occurred in six cases (8.6%) in the IONM group, which was lower than that in the control group (21.3%, P = 0.032). Postoperative pulmonary complications were found in five cases (7.1%) and 14 in the control group (18.8%, P = 0.037). The postoperative hospital stay in the IONM group was significantly shorter than that in the control group (8 vs. 12, median, P < 0.001). The number of RLN lymph nodes harvested in the IONM group was higher than that in the control group (13.74 ± 5.77 vs. 11.03 ± 5.78, P = 0.005). The sensitivity and specificity of IONM monitoring VCP were 83.8% and 100%, respectively. A total of 66.7% of patients with a reduction in signal showed transient VCP, whereas 100% with a loss of signal showed permanent VCP.

CONCLUSION

IONM is feasible in minimally invasive McKeown esophagectomy. It showed advantages for distinguishing RLN and achieving thorough mediastinal lymphadenectomy with less RLN injury. Abnormal IONM signals can provide an accurate prediction of postoperative VCP incidence.

Efficacy of Intraoperative Recurrent Laryngeal Nerve Monitoring During Thoracoscopic Esophagectomy for Esophageal Cancer: A Systematic Review and Meta-Analysis

Background: Recurrent laryngeal nerve paralysis (RLNP), a severe complication of mini-invasive esophagectomy, usually occurs during lymphadenectomy adjacent to recurrent laryngeal nerve. This systematic review and meta-analysis aimed to evaluate the efficacy of intraoperative nerve monitoring (IONM) in reducing RLNP incidence during mini-invasive esophagectomy. Methods: Systematic literature search of PubMed, EMBASE, EBSCO, Web of Knowledge, and Cochrane Library until June 4, 2021 was performed using the terms "(nerve monitoring) OR neuromonitoring OR neural monitoring OR recurrent laryngeal nerve AND (esophagectomy OR esophageal)." Primary outcome was postoperative RLNP incidence. Secondary outcomes were sensitivity, specificity, and positive and negative predictive values for IONM; complications after esophagectomy; number of dissected lymph nodes; operation time; and length of hospital stay. Results: Among 2,330 studies, five studies comprising 509 patients were eligible for final analysis. The RLNP incidence was significantly lower (odds ratio [OR] 0.33, 95% confidence interval [CI] 0.12-0.88, p < 0.05), the number of dissected mediastinal lymph nodes was significantly higher (mean difference 4.30, 95%CI 2.75-5.85, p < 0.001), and the rate of hoarseness was significantly lower (OR 0.14, 95%CI 0.03-0.63, p = 0.01) in the IONM group than in the non-IONM group. The rates of aspiration (OR 0.31, 95%CI 0.06-1.64, p = 0.17), pneumonia (OR 1.08, 95%CI 0.70-1.67, p = 0.71), and operation time (mean difference 7.68, 95%CI -23.60-38.95, p = 0.63) were not significantly different between the two groups. The mean sensitivity, specificity, and positive and negative predictive values for IONM were 53.2% (0-66.7%), 93.7% (54.8-100%), 71.4% (0-100%), and 87.1% (68.0-96.6%), respectively. Conclusion: IONM was a feasible and effective approach to minimize RLNP, improve lymphadenectomy, and reduce hoarseness after thoracoscopic esophagectomy for esophageal cancer, although IONM did not provide significant benefit in reducing aspiration, pneumonia, operation time, and length of hospital stay.

Preoperative computed tomography predicts the risk of recurrent laryngeal nerve paralysis in patients with esophageal cancer undergoing thoracoscopic esophagectomy in the prone position

BACKGROUND

Recurrent laryngeal nerve paralysis (RLNP) after thoracoscopic esophagectomy for esophageal cancer (EC) is known to be a major complication leading to poor quality of life. RLNP is mainly associated with surgical procedures performed near the RLN. Therefore, with focus on the region of the RLN, we used preoperative computed tomography to investigate the risk factors of RLNP in patients with EC undergoing thoracoscopic esophagectomy.

METHODS

We retrospectively examined 77 EC patients who underwent thoracoscopic esophagectomy in the prone position at our department between January 2010 and December 2018. Bilateral cross-sectional areas (mm²) of the fatty tissue around the RLN at the level of the lower pole of the thyroid gland were measured on preoperative axial computed tomography (CT) images. Univariate and multivariate logistic regression analysis was used to evaluate the association between the incidence of RLNP and patient clinical factors, including the cross-sectional areas.

RESULTS

RLNP occurred in 24 of 77 patients (31.2%). The incidence of RLNP was significantly more frequent on the left side than on the right. (26% vs. 5.2%, respectively). Univariate analysis identified the following left RLNP risk factors: intrathoracic operative time (> 235 min), and area around the RLN (> 174.3 mm²). Multivariate analysis found that the area around the RLN was an independent risk factor of left RLNP.

CONCLUSION

An increased area around the RLN measured on an axial CT view at the level of the lower pole of the thyroid gland was a risk factor of RLNP in EC patients undergoing thoracoscopic esophagectomy in the prone position.

Intraoperative neuromonitoring during prone thoracoscopic esophagectomy for esophageal cancer reduces the incidence of recurrent laryngeal nerve palsy: a single-center study

The incidence of recurrent laryngeal nerve palsy (RLNP) following minimally invasive esophagectomy has yet to be satisfactorily reduced. Use of intraoperative neuromonitoring (IONM), specifically of the RLN, during thyroidectomy has been reported to reduce the incidence of RLN injury. We now apply IONM during curative prone thoracoscopic esophagectomy, and we conducted a retrospective study to evaluate the feasibility and efficacy of intermittent monitoring of the RLN during the surgery. The study involved 32 consecutive patients who underwent esophagectomy with radical lymph node dissection for esophageal cancer. The patients were of two groups: an IONM group (n = 17) and a non-IONM group (n = 15). We chiefly strip around the esophagus preserving the membranous structure, which contains the tracheoesophageal artery, lymph nodes, and RLN. In the IONM group patients, we stimulated the RLN and measured the electromyography (EMG) amplitude after dissection, at the dissection starting point and dissection end point on both sides. For the purpose of the study, we compared outcomes between the two groups of patients. IONM was carried out successfully in all 17 patients in the IONM group. The incidence of RLNP was significantly reduced in this group. We found that both RLNs can be identified by mean of IONM easily, immediately, and safely and that the EMG amplitude attenuation rate is particularly useful for predicting RLNP.

Efficacy of intraoperative recurrent laryngeal neuromonitoring during surgery for esophageal cancer

AIM

To evaluate the efficacy of intraoperative neuromonitoring in identifying recurrent laryngeal nerves and decreasing the incidence of nerve injury in minimally invasive esophagectomies for esophageal cancers.

METHODS

A total of 167 minimally invasive esophagectomy patients were retrospectively reviewed. They were divided into intraoperative neuromonitoring (n = 84) and no intraoperative neuromonitoring (n = 83) groups, based on whether or not intraoperative neuromonitoring was used during surgery. We compared short-term surgical outcomes and incidence of recurrent laryngeal nerve palsy between the two groups before and after propensity score matching. The association between the loss of signal and recurrent laryngeal nerve palsy was also evaluated.

RESULTS

The incidence of recurrent laryngeal nerve palsy (grade 2 and higher) was lower in the intraoperative neuromonitoring group than in the no intraoperative neuromonitoring group (6.0% vs 21.2%, P = 0.02). The rate of recurrent laryngeal nerve palsy recovery within 6 months was also significantly higher in the intraoperative neuromonitoring group (87.5% vs 20.0%, P < 0.01). The positive and negative predictive values of intraoperative neuromonitoring for recurrent laryngeal nerve palsy were 60% (9/15) and 86.9% (60/69), respectively. The duration from paralysis to recovery was shorter in recurrent laryngeal nerve palsy cases with negative loss of signal results than in cases with positive loss of signal results (median: 43 days vs 95 days).

CONCLUSION

Intraoperative neuromonitoring is useful in identifying recurrent laryngeal nerves and may aid in reducing the incidence of recurrent laryngeal nerve injury during esophageal surgery.

Recurrent laryngeal nerve monitoring during totally robot-assisted Ivor Lewis esophagectomy

Purpose

The robot-assisted approach for Ivor Lewis esophagectomy offers an enlarged, three-dimensional overview of the intraoperative situs. The vagal nerve (VN) can easily be detected, preserved, and intentionally resected below the separation point of the recurrent laryngeal nerve (RLN). However, postoperative vocal cord paresis can result from vagal or RLN injury during radical lymph node dissection, presenting a challenge to the operating surgeon.

Methods

From May to August 2019, 10 cases of robot-assisted minimally invasive esophagectomy (RAMIE) with extended 2-field lymphadenectomy, performed at the University Medical Center Mainz, were included in a prospective cohort study. Bilateral intermittent intraoperative nerve monitoring (IONM) of the RLN and VN was performed, including pre- and postoperative laryngoscopy assessment.

Results

Reliable mean signals of the right VN (2.57 mV/4.50 ms) and the RLN (left 1.24 mV/3.71 ms, right 0.85 mV/3.56 ms) were obtained. IONM facilitated the identification of the exact height of separation of the right RLN from the VN. There were no cases of permanent postoperative vocal paresis. Median lymph node count from the paratracheal stations was 5 lymph nodes.

Conclusion

IONM was feasible during RAMIE. The intraoperative identification of the RLN location contributed to the accuracy of lymph node dissection of the paratracheal lymph node stations. RLN damage and subsequent postoperative vocal cord paresis can potentially be prevented by IONM.

Recent advances in minimally invasive esophagectomy for squamous esophageal cancer

Over the past decade there has been tremendous development in the clinical application of minimally invasive esophagectomy (MIE) for the treatment of squamous esophageal carcinoma. The major challenges in the performance of MIE include limitations in visualization and manipulation within the confined, rigid thoracic cavity; the need for adequate patient positioning and anesthetic techniques to accommodate the surgical exposure; and changes in the surgical steps for achieving radical nodal dissection, especially for the superior mediastinum. The surgical procedure for MIE is more and more standardized, and there is an increasing practice of MIE worldwide. Randomized trials and meta-analyses have confirmed the advantages of MIE over open esophagectomy, including a significantly lower rate of complications and shorter hospital stays. The recent application of robotics technologies for MIE has further enhanced the quality and safety of the surgical dissection, while intraoperative nerve monitoring has contributed to a lower rate of recurrent laryngeal nerve palsy. With the application of new technologies, we expect further improvement in surgical outcomes for MIE in the treatment of squamous esophageal cancer.

Lymph node dissection and recurrent laryngeal nerve protection in minimally invasive esophagectomy

Until now, neoadjuvant therapy plus surgical resection of the primary tumor and potential metastatic lymph nodes (LNs) has been the current optimal treatment for locally advanced thoracic esophageal cancer (EC). LN metastasis is one of the most negative prognostic factors for thoracic esophageal squamous cell carcinoma (ESCC). However, the extent of LN dissection for thoracic ESCC has long been controversial worldwide. LNs along the recurrent laryngeal nerve (RLN) were reported to have the highest frequency of metastases in thoracic ESCC, so lymphadenectomy along the bilateral RLN is necessary but quite challenging because of a high frequency of recurrent nerve palsy and related postoperative complications. With the development of minimally invasive devices and techniques in recent years, minimally invasive esophagectomy (MIE) has been widely applied in EC surgery. The topics of what the optimal extent of lymphadenectomy is and how the recurrent nerve should be well protected during MIE have been debated in recent years. The purpose of our review is specifically to address the patterns of LN metastasis, the extent of LN dissection, and the protection of the RLN in MIE for thoracic ESCC.

Combined recurrent laryngeal nerve monitoring and one-lung ventilation using the EZ-Blocker and an electromyographic endotracheal tube

Background

Intraoperative neuromuscular monitoring (IONM) is a widespread procedure to identify and protect the recurrent laryngeal nerve (RLN) during thyroid surgery. However, for left thoracic surgery with high risk of RLN injury, both reliable recurrent laryngeal nerve monitoring and one-lung ventilation could interfere.

Methods

In this prospective study, a new method for IONM during one-lung ventilation combining RLN monitoring with an electromyographic (EMG) endotracheal tube (ETT) and lung separation using the EZ-Blocker (EZB) is described and its clinical feasibility and effectiveness were assessed.

Results

A total of 14 patients undergoing left upper lobe surgery and left upper mediastinal lymph node dissection were enrolled. The EZB was introduced and positioned without any problems and sufficient lung collapse was achieved in all patients. No tracheobronchial injuries or immediate complications occurred. A stable EMG signal was present in all patients and no RLN palsy and no negative side effects of the NIM EMG ETT or the EZB were observed postoperatively.

Conclusions

The described method is technically feasible, easy to apply and save. It provides both reliable IONM and independent lung separation for optimal surgical exposure. The combined use of the EZB and the NIM EMG ETT might reduce the risk for RLN palsy and impaired lung separation during left thoracic surgery with high risk for RLN injury.