Mediastinoscopic Esophagectomy Research Articles

428. MIDDLE MEDIASTINAL LYMPHADENECTOMY IN MEDIASTINOSCOPIC ESOPHAGECTOMY FOR ESCC

Abstract (Introduction) In mediastinoscopic esophagectomy, it is necessary to secure a view of the deep middle mediastinum. Although tracheal carina lymph nodes can be stably dissected using a cervical approach, but they are dissected using a hiatal approach when it is difficult to secure the field of view. (Middle mediastinum dissection) It is important to at least peel off the tracheal membrane or azygos vein in order to reduce the risk of secondary injury in the hiatal approach, even if cervical approach is difficult. In that case, the attachment between the esophagus and subcarinal tissue should be maintained for the en-block dissection. In the hiatal approach, the dissection along the pericardial and aortic surface is continuous with the dissection layer in the cervical approach and left and right tracheal cartilage are exposed enough. In the left side, the dissection along the inferior pulmonary vein is connected to the dissection of No.109L lymph node. Then, in the right side, similarly dissect the subcarinal lymph nodes along the right bronchus (No.109R lymph node). At this time, it is important to carefully check the position of azygos vein to avoid injury. Finally, the lymph nodes at the apex of the tracheal carina are sufficiently cauterized and dissected. (Conclusion) When it is difficult to reach the subcarinal tissue in cervical approach due to body type or tumor factor, the hiatal approach is necessary for sufficient lymphadenectomy of the middle mediastinum. At that case, prior detachment of the tracheal membrane and azygos vein will be important to reduce the risk of secondary injuries. Maintaining the continuity between the esophagus and dissected tissue is also important for the stable field of view.

572. TECHNICAL DETAIL AND SHORT-TERM OUTCOMES OF ROBOT-ASSISTED CERVICAL ESOPHAGECTOMY (RACE) WITH BILATERAL CERVICAL APPROACH FOR ESOPHAGEAL CANCER

Abstract Background The transcervical mediastinoscopic esophagectomy is a relative new technique that has gradually demonstrated because of its ease of dissection along the organ sheath and its less invasive nature. However, the conventional cervical approach to mediastinoscopy has been reported to have a relatively high rate of recurrent nerve palsy due to interference in the mediastinum caused by the straight forceps. The robot-assisted transcervical esophagectomy (RACE) approach is novel procedure expected to reduce these interferences and improve maneuverability around the recurrent nerve. In this report, we describe a surgical technique and short-term outcome of RACE. Methods In this study, we included 26 RACE cases performed between Feb 2023 to Feb 2024. Principally, our hospital performs transcervical esophagectomy mainly on patients who are difficult to approach by transthoracic approach due to history of thoracic diseases, etc. In our department, transcervical esophagectomy is usually performed via a bilateral cervical approach, starting from the right neck and continuing to the left neck, and RACE is performed using the da Vinci Xi via a bilateral cervical approach as well. Recently, we have been shortening the operation time by performing simultaneous cervical and abdominal operations without muscle relaxation using NIM. Results Patient background: mean age 74.5, male to female ratio 22:4, cStage I/II/III/IV: 13/3/9/1, NAC: 46.1%, more than 80% had some history of pulmonary disease/systemic history. All patients underwent RACE via bilateral cervical approach, and no intraoperative complications or thoracoscopic conversion were observed. Postoperative complications (CD Grade≥1) included recurrent nerve palsy in 15.6% and respiratory complications in 7.6%. In addition, the recent operation with simultaneous cervical/abdominal NIM and no muscle relaxant has significantly shortened the average total operative time to 4 hours and 40 minutes. Conclusion Robot-assisted Cervical Esophagectomy (RACE) is a relatively safe procedure that offers a natural anatomic approach, fewer respiratory complications, and a significant reduction in operative time due to simultaneous neck and abdominal manipulation. With the advancement of robotics and devices, RACE is expected to become more effective and more widely used in the future.

Tracheal injury diagnosed by a sudden increase in end-tidal carbon dioxide levels during mediastinoscopic subtotal esophagectomy: a case report

BackgroundMediastinoscopic surgery for esophageal cancer facilitates early postoperative recovery. However, it can occasionally cause serious complications. Here, we present the case of a patient with a tracheal injury diagnosed by a sudden increase in end-tidal carbon dioxide (EtCO2) during mediastinoscopic subtotal esophagectomy.Case presentationA 52-year-old man diagnosed with esophageal cancer was scheduled to undergo mediastinoscopic subtotal esophagectomy. During the mediastinoscopic procedure, the EtCO2 level suddenly increased above 200 mmHg, and the blood pressure dropped below 80 mmHg. We immediately asked the operator to stop insufflation and found a tracheal injury on the right side of the trachea near the carina by bronchoscopy. The endotracheal tube was replaced with a double-lumen tube, and the trachea was repaired via right thoracotomy. There were no further intraoperative complications. After surgery, the patient was extubated and admitted to the intensive care unit.ConclusionsMonitoring EtCO2 levels and close communication with the operator is important for safely managing sudden tracheal injury during mediastinoscopic esophagectomy.

Robot-assisted transcervical esophagectomy with a bilateral cervical approach for thoracic esophagectomy.

Thoracic esophageal cancer resection through the neck approach has recently been reported as mediastinoscopic surgery. We present the first report of a new minimally invasive technique for thoracic esophageal cancer: robot-assisted transcervical esophagectomy with a bilateral cervical approach. Ten cases of robot-assisted bilateral transcervical esophagectomy performed at the National Cancer Center Hospital East, Japan, from February 2023 to August 2023 were reviewed. The short-term surgical outcomes were presented, and the feasibility and efficacy of this procedure were discussed. The mean operation time for the cervical procedure was 184.2 ± 23.6min. The total time for the whole procedure was 472.7 ± 28.4min, and total intraoperative blood loss was 162.2 ± 40.0ml. Among the 10 cases, one patient developed recurrent nerve paralysis, one patient developed pulmonary complications, and no patients developed postoperative pneumonia. The median postoperative hospital stay was 22 (range: 12-43) days. No patients developed severe postoperative surgical complications, which were graded as Clavien-Dindo ≥ III. The total number of surgically harvested mediastinal lymph nodes was 37.2 ± 11.2. Robot-assisted bilateral transcervical esophagectomy, a novel procedure for thoracic esophageal cancer, was safe and feasible. Using this procedure, the incidence of recurrent nerve palsy, which is a problem with transcervical esophagectomy and mediastinoscopic esophagectomy, is expected to decrease.

Transhiatal bilateral cervical approach for mediastinoscopy-assisted esophagectomy: A retrospective cohort study.

The McKeown minimally invasive esophagectomy (McMIE) procedure has various limitations, including surgical contraindications and a high rate of postoperative pulmonary complications. A novel mediastinoscopic esophagectomy procedure was described in this study by using esophageal invagination and a transhiatal and bilateral cervical approach (EITHBC). According to the mode of operation, a total of 259 patients were divided into two groups, among which 106 underwent EITHBC and 153 underwent McMIE. The number of lymph nodes dissected, intraoperative outcomes, and postoperative outcomes were compared between the two groups of patients. The results revealed that the average number of resected lymph node in the EITHBC group was significantly higher in the recL106 and TbL106 stations (recL106: 1.75 vs. 1.51, p=0.016, TbL106: 1.53 vs. 1.19, p=0.016) and significantly lower in the 107 stations (1. 74 vs. 2. 07, p < 0.001) than in the McMIE group. The intraoperative blood loss in the EITHBC group was significantly lower than that in the McMIE group (63.30 vs. 80.45mL, p<0.001). The incidence of postoperative pulmonary complications in the EITHBC group was lower than that in the McMIE group (14.15% vs. 27.45%, p=0.008). The incidence of recurrent laryngeal nerve paralysis in the EITHBC group was significantly higher than that in the McMIE group (26.41% vs. 10.46%, p=0.003). Compared with the McMIE procedure, the EITHBC procedure has advantages in terms of removing the upper mediastinal lymph nodes and reducing postoperative pulmonary complications.

372. INVESTIGATION OF RISK FACTORS OF POSTOPERATIVE PNEUMONIA IN MEDIASTINOSCOPIC ESOPHAGECTOMY

Abstract Background Pneumonia is a usual complication in esophagectomy. Although frequency of pneumonia in mediastinoscopic esophagectomy is low, risk factors for pneumonia are unclear. The risk factors are investigated. Methods Two hundred and forty-four patients with mediastinoscopic esphagectomy and gastric tube reconstruction for esophageal cancer from 2016 to 2021 in our hospital were retrospectively considered in the present study. Postoperative pneumonia was diagnosed as Clavien-Dindo grade 2 or higher. Patients were divided into two groups with (n = 21) and without (n = 223) pneumonia, and background, surgical factors, or histopathological factors were investigated. Results Post-operative pneumonia was observed in 21 patients (8.6%), and pre-operative albumin, PNI (&amp;lt; 45), PLR (&amp;gt; 122), and operative bleeding (&amp;gt;134) were significantly related with post-operative pneumonia in the univariate analysis (p &amp;lt; 0.05). Age and previous respiratory disease were also tended to be related with post-operative pneumonia, but not significant. Low PNI was an independent risk factor of post-operative pneumonia in the multivariate analysis (p = 0.047, OR = 2.74). Post-operative pneumonia was not related to the complications, such as anastomosis leakage or recurrent nerve paralysis. No correlation with postoperative pneumonia was observed even in patients with preoperative respiratory dysfunction. Discussion PNI has been reported to be useful as a predictor of postoperative complications. In the present study, it was also a predictor factor of postoperative pneumonia. Early nutritional intervention for undernourished esophageal cancer patients may prevent postoperative pneumonia. Conclusion Low PNI can be a predictive factor of postoperative pneumonia in the mediastinoscopic esophagectomy.

196. MINIMALLY INVASIVE ESOPHAGECTOMY WITH AWARENESS OF THE THIN MEMBRANOUS DENSE CONNECTIVE TISSUES AROUND THE ESOPHAGUS

Abstract Background We have clinically introduced the ‘mediastinoscopic esophagectomy with lymph node dissection’ (MELD) to esophagectomy for thoracic esophageal cancer, performed under pneumomediastinum via trans-bicervical and transhiatal approach since 2014. In parallel with this, we have been conducting histological studies of the thin membranous dense connective tissue (TMDCT) around the esophagus and utilizing the results during these surgeries to ensure a rational esophagectomy. Here, we describe the differences in the visibility of TMDCT between the two approaches for esophagectomy. Methods We retrospectively examined the visibility of TMDCT in surgical videos of trans-mediastinnal and trans-right thoracic approaches after 2015 to determine the characteristics of each approaches. Results The trans-mediastinal approach reaches the visceral sheath by entering just dorsal to the esophagus in the right neck, and the TMDCT is seen in a bubbled appearance. Unlike the right thoracic approach, the visceral sheath can be easily reached without a pleural incision. The adipose tissue including lymph nodes around the left recurrent laryngeal nerve (RLN) showed a clear dissection layer between the left subclavian artery, but the boundary between the lymph nodes around the left RLN and the aorta was unclear near the aortic arch, which was thought to be due to the lack of visceral sheath around No.106tbL. On the other hand, the trans-right thoracic approach showed a slightly shiny visceral sheath covering the surface of the thoracic duct on the dorsal side of the esophagus. In the left superior mediastinum, the left RLN and RLN lymph nodes were located on the organ side of the visceral sheath covering the esophagus and trachea. In right and left sides, the visceral sheath was obscured near the branch of the RLN from the vagus nerve, but the RLNs ran cranially on the medial side of the visceral sheaths. Conclusion We reported how the TMDCT is visualized with each surgical approach. The visceral sheath was visualized as a bubbly structure in the trans- mediastinal approach and as a slightly shiny areal structure in the trans-right thoracic approach. Recognition of the TMDCT around the esophagus was useful for safe and rational lymph nodes dissection regardless of the surgical approach.

278. MEDIASTINOSCOPIC ESOPHAGECTOMY WITH INTRAOPERATIVE NERVE MONITORING FOR ESOPHAGOGASTRIC JUNCTION ADENOCARCINOMA; A SINGLE-CENTER INITIAL EXPERIENCE

Abstract Background In recent years, adenocarcinoma of esophagogastric junction (EGJ) has been on the increase in Japan. Although laparoscopic resection by the transhiatal approach is commonly used, patients often have difficulty with mediastinal lymph node dissection and reconstruction after resection. Since 2020, we have been performing mediastinoscopic esophagectomy for EGJ adenocarcinoma patients with esophageal invasion exceeding 3 cm in length or with a large tumor diameter. We report on the short-term results of the surgery performed. Methods Of 15 patients with adenocarcinoma of the esophagogastric junction who underwent radical esophagectomy at our hospital during a 36-month period from January 2020 to December 2022, 5 patients underwent mediastinoscopic esophagectomy without thoracic incisions. Surgery consisted of mediastinoscopic and laparoscopic subtotal esophagectomy, mediastinal lymph node dissection, and posterior mediastinal gastric tube reconstruction with cervical anastomosis. In all cases, continuous left recurrent nerve monitoring was performed intraoperatively. Short-term surgical outcomes were evaluated in terms of age, gender, TNM classification, stage, preoperative complications, operation time, blood loss, tumor diameter, length of esophageal invasion, postoperative complications, and postoperative hospital stay. Results All five patients were male, with a mean age of 67.8 years. 4 of the 5 patients had preoperative complications. Tumor localization was Siewert classification type I in 4 patients and type II in 1. The average tumor length and esophageal invasion length was 44 ± 26 mm and 38 ± 11 mm respectively. The average operation time was 395 ± 29 minutes and blood loss was 38 ± 39 mL. Lymph node metastases was revealed in three patients. No postoperative anastomotic leakage or recurrent nerve palsy was observed. One patient developed postoperative aspiration pneumonia but was cured without reintubation. Conclusion Mediastinoscopic esophagectomy for EGJ adenocarcinoma was performed safely. RCTs conducted in Western countries reported that esophagectomy with cervical anastmosis is associated with higher rates of recurrent nerve palsy than esophagectomy by the transhiatal approach. The use of a mediastinoscope to visualize the recurrent nerve and the use of intraoperative nerve monitoring devices might reduce the frequency of recurrent nerve palsy.

400. CONSTRUCTION OF A MODULAR SYSTEM OF ‘INFLATABLE SINGLE-INCISION MEDIASTINOSCOPY ESOPHAGECTOMY’ BASED ON FASCIA ANATOMY

Abstract Background We improved Inflatable Single-Incision Mediastinoscopy esophagectomy to implement the simultaneous laparoscopic esophagectomy with inflatablesingle-Incision mediastinoscope and lymphadenectomy along bilateral recurrent laryngeal nerves under mediastinoscopy through a single left-neck incision and formed the concept of modular treatment of inflatable mediastinoscopic esophagectomy based on fascial anatomy which we can achieve standardized add programmed esophageal dissociation, greatly shorten the learning curve, make it easier to popularize and promote, and help us to control the operation time and complications. Methods According to anatomy of the periesophageal fascia we summarized six surgical modules, respectively is: To make the neck incision, dissociate posterior and left esophagus, dissociate anterior and right esophagus, lymphadenectomy along left recurrent laryngeal nerves, lymphadenectomy along right recurrent laryngeal nerves, dissect the Subcarinal lymph nodes. The clinical data of patients undergoing esophagectomy with inflatable single-pore mediastinoscope from February 2020 to February 2021 in our hospital were summarized and analyzed, and compared with the data of minimally invasive thoracic esophagectomy, in order to verify the clinical application effect of this modular system. Results In the validation study of modularization in this subject, no perioperative death was found in the 44 patients and the R0 resection rate was 100% confirmed by postoperative pathology. The average operation time was 204.9 ± 45.4 minutes, mean intraoperative blood loss was 64.6 ± 45.5 mL, average number of lymph nodes removed was 19.5 ± 9.1, average length of hospital stay was 27.0 ± 18.17 days, postoperative anastomotic fistula (2.27%), anastomotic stenosis (13.64%), chylous leakage (0%), pleural effusion (4.55%), and pulmonary infection (9.09%), better than the control group. The incidence of postoperative hoarseness (18.19%) which needed to be improved. Conclusion This standardized and modular surgical procedure description based on fascia anatomy is proposed for the first time for the esophagectomy under inflatable mediastinoscope, and is an exploration of the construction of a modular system for this surgical procedure. This modular system enables us to achieve standardized, programmed and rapid esophageal dissociation, which has good clinical application value.

Novel Mediastinoscope-Assisted Minimally Invasive Esophagectomy for Esophageal Cancer: A Systematic Review and Meta-analysis.

Minimally invasive surgery is an expanding field of surgery that has replaced many open surgical techniques. Surgery remains a cornerstone in the treatment of esophageal cancer, yet it is still associated with significant morbidity and technical difficulties. Mediastinoscope-assisted esophagectomy is a promising technique that aims to decrease the surgical burden and enhance recovery. PubMed, MEDLINE, and EMBASE databases were searched for publications on mediastinoscope-assisted esophagectomies for esophageal cancer. The primary endpoint was a postoperative anastomotic leak, while secondary endpoints were assessment of harvested lymph nodes (LNs), blood loss, chyle leak, hospital length of stay (LOS), operative (OR) time, pneumonia, wound infection, mortality, and microscopic positive margin (R1). The pooled event rate (PER) and pooled mean were calculated for binary and continuous outcomes respectively. Twenty-six out of the 2274 searched studies were included. The pooled event rate (PER) for anastomotic leak was 0.145 (0.1144; 0.1828). The PERs for chyle leak, recurrent laryngeal nerve injury/hoarseness, postoperative pneumonia, wound infection, early mortality, postoperative morbidity, and microscopically positive (R1) resection margins were 0.027, 0.185, 0.09, 0.083, 0.020, 0.378, and 0.037 respectively. The pooled means for blood loss, hospital stay, operative time, number of total harvested LNs, and number of harvested thoracic LNs were 159.209, 15.187, 311.116, 23.379, and 15.458 respectively. Mediastinoscopic esophagectomy is a promising minimally invasive technique, avoiding thoracotomy, patient repositioning, and lung manipulation; thus allowing for shorter surgery, decreased blood loss, and decreased postoperative morbidity. It can also be reliable in terms of oncological safety and LN dissection.

379. ENLIGHTENMENT OF THE VENOUS ANATOMY OF THE ESOPHAGUS—AN ANOMALY CAPTURED UNDER MEDIASTINOSCOPY

Abstract Distant organ metastasis often occurs early in the course of esophageal cancer development and is associated with a poor prognosis. The modes of metastasis include hematological and lymphatic routes. Although in the literature the venous outflow of the esophagus is described to occur through the esophageal vein into the azygous vein, which subsequently joins the superior vena cava, the detained anatomy of the venous and lymphatic systems of the esophagus remains to be further investigated. We aimed to elucidate the regional anatomy of the venous system surrounding the esophagus via mediastinoscopic esophagectomy. Between January 2021 to January 2022, six patients with early esophageal cancer without apparent distant metastasis underwent minimally invasive esophagectomy and posterior mediastinal reconstruction with mediastinoscopy in our hospital. Detailed anatomy was captured and the spatial relationship between the esophageal vein and its draining vein was assessed intraoperatively and thoroughly reviewed postoperatively for any anomalies. A venous anomaly was seen in one out of six patients where the esophageal vein drained into the left pulmonary vein rather than into the azygous vein. This anomaly was not detectable on the preoperative CT images. Hemostasis of the esophageal vein was achieved without major hemorrhage or injury to surrounding tissues. The esophageal specimen showed a localized ulcerative lesion in the midthoracic esophagus that was consistent with moderately differentiated squamous cell carcinoma, pT3N0M0 pStage IIB, with v1 and ly1 invasion. The patient will remain under surveillance for recurrence. Direct venous drainage into the systemic circulation may attribute to its high rates of distant metastasis in esophageal cancer. This mechanism supports the higher prevalence of metastasis to the liver over the lung, and relatively high rates of bone and brain metastases. Close attention should be paid when performing esophagectomy as injuries to the esophageal vein and inadequate hemastasis may result in catastrophic bleeding when a direct connection with the systemic circulation is present.

172. THE MEDIASTINOSCOPIC RADICAL ESOPHAGECTOMY WITH A TRANS-BICERVICAL APPROACH USING INTRAOPERATIVE NERVE MONITORING (IOMN)

Abstract We developed ‘mediastinoscopic esophagectomy with lymph node dissection’ (MELD), performed under pneumomediastinum via a trans-bicervical and transhiatal approach using cadavers. A clinical trial on the feasibility and safety of MELD showed it to be useful for complete mediastinal lymph node dissection. We report the indications and novel aspects of MELD. MELD was indicated for patients of thoracic esophageal cancer without bulky primary lesions or lymph node metastases. MELD was performed in 16 patients. First, 101R and part of the 106recR lymph nodes were dissected in open surgery. After attaching an APS electrode for intraoperative nerve monitoring (IOMN) to the right vagus nerve, open surgery was changed to the pneumomediastinal method. The dorsal side of the esophagus was dissected along the visceral sheath. The 106tbL lymph nodes and the106recR lymph nodes were dissected using a right trans-cervical pneumomediastinal approach. The 106recL lymph nodes were dissected using a left trans-cervical pneumomediastinal approach. The median pneumomediastinal operation time was 320 minutes. The median amount of bleeding was 230 mL, and the median postoperative hospital stay was 16 days. Regarding complications, eight patients developed recurrent laryngeal nerve palsy (right, n = 3; left, n = 2; bilateral, n = 3), but no patients required conversion to thoracotomy, and no leakage, pneumonia, or operative deaths occurred. After incorporating the use of IOMN, the incidence of recurrent laryngeal nerve palsy was drastically reduced recurrent laryngeal nerve palsy was drastically decrease. Previous clinical trials shown that MELD can retrieve the mediastinal lymph nodes at the same level as thoracoscopic esophagectomy. The incidence of recurrent laryngeal nerve palsy was reduced by IONM; thus, MELD is considered a feasible procedure for radical esophagectomy.

182. LAPAROSCOPIC-ASSISTED SINGLE-PORT MEDIASTINOSCOPIC ESOPHAGECTOMY CAN PROVIDE A SAFE AND EFFECTIVE SURGICAL OPTION FOR PATIENTS WITH SPECIFIC ESOPHAGEAL CANCERS

Abstract The majority of traditional minimally invasive esophagectomies are transthoracic esophagectomies. However, transthoracic esophagectomy is often difficult to perform in some patients with pulmonary insufficiency, severe pleural adhesions, chest deformities, and poor tolerance for single-lung ventilation. For this reason, we propose laparoscopic-assisted single-port mediastinoscopic esophagectomy as a potential surgical treatment for patients who are unsuitable for transthoracic esophagectomy. The goal of this study was to report the effectiveness and safety of its treatment. This study retrospectively collected clinical data from hard-to-reach transthoracic patients who underwent laparoscopic-assisted single-port mediastinoscopic esophagectomy at our center from October 2016 to August 2021 to report their perioperative treatment outcomes. Data for continuous variables are expressed as mean ± standard deviation, and categorical variables are expressed as n [%]. All data were analyzed using SPSS 25.0 software. A total of 8 cases were included and all completed the surgery successfully. The average operating time was 266.14 min, the average intraoperative bleeding was 114.29 mL, the average number of lymph nodes obtained was 13.29, the average number of recurrent laryngeal nerve (RLN) lymph nodes was 3.14, the rate of RLN lymph nodes obtained was 75%, the average postoperative hospital stay was 22.29 days. Postoperative complications included type I vocal cord paralysis [37.5%], anastomotic leak [25%], pneumonia [12.5%], pleural effusion [25%], and type I Chyle Leak [12.5%], with no perioperative deaths. There was one recurrence and no death within 1 year postoperatively. The results of this study suggest that laparoscopic-assisted single-port mediastinoscopic esophagectomy can provide a safe and effective treatment option for patients with esophageal cancer who have difficulty undergoing transthoracic esophagectomy and can achieve a more satisfactory short-term survival outcome.

166. A STUDY OF THE LEARNING CURVE FOR LAPAROSCOPIC-ASSISTED SINGLE-PORT MEDIASTINOSCOPIC ESOPHAGECTOMY

Abstract Laparoscopic-assisted single-port mediastinoscopic esophagectomy is a safe and effective emerging minimally invasive esophagectomy. However, nothing has been reported about the learning curve for this technique. The goal of this study was to analyze the learning curve of this technique and to determine the number of procedures performed to achieve different levels of proficiency to improve surgeons’ understanding of the learning process of this new technique. This study retrospectively collected clinical data on consecutive laparoscopic-assisted single-port mediastinoscopic esophagectomies performed by the same surgeon at our center from October 2016 to August 2021. A simple scatter plot of the number of procedures versus procedure time and its trend line were plotted, using procedure time as an indicator of efficiency. Learning curves were quantitatively assessed by unadjusted cumulative sum values using the cumulative summation method, different segments were derived using joint point linear regression analysis, and variables were compared between subgroups using trend analysis. The survival analysis was performed using the Kaplan–Meier method. The learning curve could be divided into 3 different stages: the 1st–91st, 91st-125th, and 125th-182nd procedures comprised the preliminary, transition, and proficient stages, respectively. Compared with the preliminary stage, the procedure time, bleeding volume, postoperative hospital stays, and the incidence of anastomotic fistula were significantly lower in the proficiency stage, whereas the number of harvested lymph nodes and the rate of recurrent laryngeal nerve lymph node harvest was significantly higher. Additionally, there were no significant differences in overall survival and disease-free survival at different stages for patients with all, different T stages, and different N stages within 1 year postoperatively. In this study, there may be 3 stages of varying proficiency in the learning curve of laparoscopic-assisted single-port mediastinoscopic esophagectomy. Approximately 91 consecutive procedures were required to overcome the preliminary stage, whereas proficiency in this technique required approximately 125 consecutive procedures. Moreover, as the learning curve reached the proficiency stage, the perioperative indicators tended to stabilize. Furthermore, the short-term survival of patients might not be influenced by technical proficiency.

A comparison of the surgical invasiveness and short-term outcomes between thoracoscopic and pneumatic mediastinoscopic esophagectomy for esophageal cancer.

Minimally invasive esophagectomy (MIE) has been widely accepted as a treatment for esophageal cancer. This retrospective study compared the short-term outcomes and surgical invasiveness between thoracoscopic esophagectomy (TE) and mediastinoscopic esophagectomy with pneumomediastinum (pneumatic mediastinoscopic esophagectomy [PME]). A total of 72 patients who underwent TE or PME were included and assessed for their surgical findings, postoperative complications, and inflammatory responses on postoperative day (POD) 1, 3, 5, and 7. The PME group exhibited a significantly shorter operative time and fewer lymph nodes retrieved than the TE group. Furthermore, the PME group tended to have greater incidences of recurrent laryngeal nerve palsy and lower incidences of atelectasis than the TE group. The PME group had significantly lower white blood cell counts on POD 5, serum C-reactive protein (CRP) levels on POD 3 than the TE group. PME seems to be less invasive than TE and can be considered the preferred option for patients with lower-stage esophageal cancer expected to have severe pleural adhesion or who cannot tolerate TE.

Transcervical inflatable mediastinoscopic esophagectomy versusthoracoscopic esophagectomy for local early- and intermediate-stage esophageal squamous cell carcinoma: A propensityscore-matched analysis.

Background and objectiveTranscervical inflatable mediastinoscopic esophagectomy (TIME) is a novel method of minimally invasive esophagectomy (MIE) for esophageal cancer. However, whether TIME is effective and feasible as conventional MIE remains unclear. This study aimed to evaluate the efficacy of TIME by comparing it with thoracoscopic esophagectomy (TE).MethodsSurgical outcomes and relapse‐free survival (RFS) rates of patients with local early‐ or intermediate‐stage thoracic esophageal squamous cell carcinoma that underwent TIME or TE from January 2017 to December 2019 were analyzed in this retrospective study. Propensity score matching was used to control the confounding factors.ResultsThe mean operation time in TIME was shorter than that in TE (p < 0.05). Patients in the TIME group achieved postoperative ambulation earlier than those in the TE group (p < 0.05). The rate of pulmonary complications was lower in TIME than in TE (p < 0.05). The number of lymph nodes harvested during surgery and the RFS rates of two groups did not have significant differences.ConclusionTIME may be a feasible and safe method to treat local early‐ and intermediate‐stage thoracic esophageal squamous cell carcinoma effectively and it could be a supplementary surgical method of TE for patients with poor pulmonary function or cannot undergo TE.

303 LONG-TERM SURVIVAL AND PULMONARY COMPLICATIONS IN MEDIASTINOSCOPIC ESOPHAGECTOMY

Abstract The radical esophagectomy for esophageal cancer is an invasive therapy due to a long one-lung ventilation. The mediastinoscopic esophagectomy in consideration of pulmonary complications became eligible for Japanese health insurance. Methods Radical esophagectomies (R0/1, gastric tube reconstruction) by thoracotomy/thoracoscopy (groupT) or mediastinoscopy (groupM) were performed for 118/58 or 225 patients with esophageal cancer. The long-term therapeutic results of mediastinoscopic radical esophagectomy are investigated. Results In clinicopathological features, younger and lower PS patients, neoadjuvant chemotherapy, advanced cases, or R1 resection were more frequent in groupT (p &amp;lt; 0.01). Pulmonary complication was not significantly different in both groups (15.5 vs 11.0%, p = 0.19), whereas the any complications, including the recurrent nerve paralysis, were significantly frequent in groupM. The 5-years overall survival was better in group M (53.0% vs 68.2%, p = 0.04), but it may be because of the difference of cancer progression. In the subgroup analysis, the overall survival rate was similar in each clinical stage. The survival of patients with pulmonary complication was significantly worse in groupT. Conclusion The survival of patients underwent trans-mediastinoscopic radical esophagectomy was not different from that with conventional esophagectomy. The influence of pulmonary complications on survival may be lower in mediastinoscopic esophagectomy.

477 MINIMALLY INVASIVE MEDIASTINOSCOPIC IVOR-LEWIS ESOPHAGECTOMY WITH CERVICAL ANASTOMOSIS FOR ESOPHAGOGASTRIC JUNCTION ADENOCARCINOMA PATIENT UNDER INTRAOPERATIVE RECURRENT LARYNGEAL NERVE MONITORING

Abstract In early 2000s, cervical anastomosis after esophagectomy was associated with a higher rate of recurrent nerve trauma than thoracic anastomosis. Recently, new technologies have been developed that reduce surgical complications. Mediastinoscopic esophagectomy is reportedly less invasive and allows faster recovery than thoracoscopic esophagectomy. Intraoperative nerve monitoring (IONM) prevents recurrent laryngeal nerve (RNL) palsy. We present the case of minimally invasive mediastinoscopic Ivor-Lewis Esophagectomy (MMIE) under IONM performed on an elderly esophagogastric junction (EGJ) adenocarcinoma patient. Methods An 84-year old man was consulted for adenocarcinoma of GEJ without lymphnode metastasis. Despite his advanced age, he had no comorbidities. We planned to perform MMIE under IONM. The procedure started with a patient lithotomy, and three trocars plus small incision were made in the upper abdomen. Celiac lymphadenectomy was performed. Subsequently, a 35 mm incision was made in the left side of the neck and a monitor was attached to left vagus nerve. Three trocars were placed with single incision surgical devices and pneumomediastinum was noticed. Mediastinoscopic esophagectomy was performed. Gastric tube reconstruction via mediastinum with cervical anastomosis was performed. Results The operation was successful. Total operation time was 393 minutes, with an estimated blood loss of 5 mL. There were no intraoperative and postoperative complications, and no RLN palsy occurred. Conclusion MMIE with cervical anastomosis under IONM is safe and less invasive especially for the respiratory system as a thoracotomy is unnecessary. Video https://www.dropbox.com/s/9yqkzg3pm619pf6/%E7%B8%A6%E9%9A%94%E9%8F%A12%E5%88%8656%E7%A7%92.mp4?dl=0.

309 ASSOCIATION BETWEEN CERVICAL ANASTOMOSIS METHODS AND ANASTOMOSIS STRICTURE AFTER ESOPHAGECTOMY FOR CANCER

Abstract Esophagectomy with three-field lymph node dissection is the most important part of advanced esophageal cancer therapy, especially for squamous cell carcinoma (SCC) patients. After esophagectomy, cervical anastomosis with gastric tube is required. However, some patients suffer anastomotic stenosis and require endoscopic balloon dilations. In this study, we investigated the relationship between cervical anastomosis methods and anastomosis stricture after esophagectomy for cancer patients. Methods Patients with esophageal cancer undergoing radical esophagectomy with cervical anastomosis were identified from the prospectively maintained database at our institution. From 2013 to 2019, 28 patients received esophagectomy with cervical lymph node dissection in our institution. Association between anastomotic methods, linear stapler vs circular stapler, and other factors (patient characteristics, surgical complications including anastomotic stenosis, and length of postoperative stay) were analyzed. Results Their average age was 63.3 years. Males and SCC cases predominated. Thirteen patients (46%) received cervical anastomosis with the circular stapler (Group C), and 11 patients (39%) received treatment with the linear stapler (Group L). None of the following variables were significant different between the two methods: preoperative chemotherapy (53.8% in group C vs. 45.5% in group L; p = 0.58), length of hospital stay (25.8 vs. 20.7 days; p = 0.15), pulmonary complications (16.7% vs. 0.0%; p = 0.36), and anastomotic leakage (33.3% vs. 9.1%; p = 0.24). However, the rate of anastomotic stenosis without malignancies was significantly higher in group C patients (66.7% vs. 0%, p &amp;lt; 0.01). Conclusion Cervical anastomosis with the linear stapler may be safer and associated with a lower stenosis rate than with the circular stapler. In future, cervical anastomosis with linear stapler after mediastinoscopic esophagectomy would be better for not only esophageal SCC patients but also esophagogastric junction adenocarcinoma patients with pulmonary complications.

112 ROBOT-ASSISTED MINIMALLY INVASIVE ESOPHAGECTOMY CAN BE PERFORMED EVEN IN LEARNING CURVE PERIOD; PROPENSITY SCORE MATCH ANALYSIS

Abstract Da Vinci Surgical System Xi was introduced in our institution in 2017. Since then we started robot-assisted minimally invasive esophagectomy (RAMIE) as private practice. Japanese national insurance system started to reimburse RAMIE in 2018. Since then, the number of RAMIE is explosively increasing. Currently the indication of RAMIE in our institution purely depends on machine availability. However, the real clinical benefit of RAMIE over conventional minimally invasive esophagectomy (MIE) remains unknown. Methods Between January 2015 and January 2020, data of 156 consecutive patients with esophageal carcinoma undergoing esophagectomy was retrospectively reviewed. After exclusion of 12 salvage esophagectomy for patients after definitive chemoradiotherapy (&amp;gt;50Gy), 10 mediastinoscopic esophagectomy, 5 esophagectomy without upper mediastinal dissection, 2 two-stage esophagectomy and 1 total pharyngo-laryngo-esophagectomy, 126 patients (46 RAMIE and 80 MIE) were included in the analysis. The 1:1 propensity score match analysis was performed to compare the short-term outcomes between RAMIE and MIE. Results After matching, 45 RAMIE and 45 MIE were analyzed. RAMIE took significantly longer thoracic operation time (370 min vs. 288 min; P &amp;lt; 0.0001). Intraoperative blood loss (80 g vs. 50 g; P = 0.0759), harvested thoracic nodes (22 vs 25; P = 0.1188), harvested upper mediastinal nodes (12 vs 12; P = 0.4233) were similar. RAMIE showed less severe postoperative morbidity (Clavien-Dindo Grade III or higher) (9% vs. 22%; P = 0.0810) and lower incidence of recurrent laryngeal nerve palsy (Clavien-Dindo Grade II or higher) (7% vs. 18%; P = 0.1076). There was no postoperative death in both groups. Conclusion Although this result contains our early learning curve period of RAMIE, short term outcome of RAMIE is acceptable from a safety point of view.