Thoracic Operation Time Research Articles

315. SHORT-TERM RESULTS OF ROBOT-ASSISTED SURGERY FOR ESOPHAGEAL CANCER IN JAPAN 5 YEARS AFTER INSURANCE COVERAGE

Abstract Background In Japan, robot-assisted surgery (RAMIE) for esophageal cancer surgery was covered by insurance in 2018, and its introduction has been rapidly progressing since then. In our department, RAMIE has been introduced and performed in 250 cases so far. In the process, we have improved the short-term results by introducing the standardization and NIM (neuromonitoring) according to the characteristics of RAMIE. In addition, we have recently expanded the use of RAMIE in advanced cancer patients due to its usefulness in stable operation. In this meeting, we will review the short- and mid-term results and discuss current issues. Methods We analyzed the short-term results of all 213 RAMIE cases performed at our department, and compared them with the short-term results of 51 post-standardization (late) MIE cases previously reported. The mid-term results to date were also reviewed. Results A total of 213 patients were included. 211, 222 mins thoracic operation time. 235, 190 ml blood loss in comparison to MIE (vs. RAMIE). Postoperative outcomes were similar: overall complications (>Grade II) were 49, 54.9%, respiratory complications were 19.6, 23.9%, and recurrent nerve palsy was 15.7, 17.4%. Risk analysis demonstrated that paralysis in RAMIE was significantly related to prolonged thoracic operation time (p=0.021) and NIM (Odds=0.38, p=0.0447). In comparison between patients with early-stage and advanced cancer, pneumonia and anastomotic complications were not different. Prognosis was 81.7/64.2% (UICC 8th) for 3-year survival in cStage II/III patients. Conclusion RAMIE was considered to be highly useful for short-term and medium-term outcomes at this time.

261. CONVERSION ESOPHAGECTOMY FOR CT4B ESOPHAGEAL CANCER - MIE VS OPEN -

Abstract Background and Aims The standard treatment for locally advanced unresectable esophageal cancer is definitive chemoradiotherapy (dCRT), however, after induction chemotherapy with a triplet chemotherapy regimen (docetaxel, cisplatin, and 5-FU: DCF) or dCRT, conversion surgery could be performed if esophageal cancer is considered resectable. Furthermore, minimally invasive surgery such as robot-assisted or thoracoscopic procedures are expected to improve the outcome of patients with advanced esophageal cancer. We investigated the feasibility of minimally invasive esophagectomy (MIE) in conversion surgery. Materials and Methods Sixty-six patients who underwent conversion thoracic esophagectomy for cT4b esophageal cancer from 2007 to 2023 were included. The short-term outcomes of 25 open esophagectomy group and 41 MIE group (8 robot-assisted and 33 thoracoscopic) were compared. Results No differences in age, gender, PS, tumor location, histology, cN, or cM were observed between the two groups. cT4b organs tended to be in the airway in the MIE group (airway 70.7% vs 44%, major vessels 19.5% vs 24%, both 9.7% vs 32%, p=0.04) and DCF therapy was significantly performed in the MIE group for induction therapy (DCF 87.8% vs 56%, dCRT 12.2% vs 44%, p<0.001). On the other hand, salvage surgery was significantly associated with open esophagectomy (24.3% vs. 52%, p=0.003). There was no difference in surgical outcomes regarding thoracic operation time (157 min vs. 180 min, p=0.09), whereas the total operation time was significantly shorter in the MIE group (392 min vs. 439 min, p=0.02). Blood loss was significantly lower in the MIE group (79 ml vs. 470 ml, p<0.001), and R0 resection rate did not differ (82.9% vs. 72%, p=0.357). There were no significant differences in postoperative complications including pneumonia (26.8% vs. 44%, p=0.183) and recurrent nerve palsy (21.9% vs. 36%, p=0.260), but anastomotic leakage was significantly lower in the MIE group (4.8% vs. 24%, p=0.04). There was no difference in median postoperative hospital stay (16 [11-20] vs. 16 [14-29] days), however, median ICU stay (3 [3-4] vs. 4 [3-4] days, p=0.03) and readmission within 1 month after discharge (2.4% vs. 16%, p=0.04) were significantly lower in the MIE group. In-hospital mortality was observed in 1 case in the MIE group and 3 in the open esophagectomy group. Conclusion Despite the bias associated with the transition of treatment modalities and surgical techniques, MIE may contribute to improved short-term outcomes in conversion surgery.

Anatomical factor associated with thoracic procedural difficulty in robot-assisted minimally invasive esophagectomy.

Robotic surgical systems with full articulation of instruments, tremor filtering, and motion scaling can potentially overcome the procedural difficulties in endoscopic surgeries. However, whether robot-assisted minimally invasive esophagectomy (RAMIE) can overcome anatomical difficulties during thoracoscopic esophagectomy remains unclear. This study aimed to clarify the anatomical and clinical factors that influence the difficulty of RAMIE in the thoracic region. Forty-five patients who underwent curative-intent RAMIE with upper mediastinal lymph node dissection for esophageal cancer were included. Using preoperative computed tomography images, we calculated previously reported anatomical indices to assess the upper mediastinal narrowness and vertebral body projections in the middle thoracic region. The factors influencing thoracic operative time were then investigated. During the thoracic procedure, the median operative time was 215 (124-367) min and the median blood loss was 20 (5-190) mL. Postoperatively, pneumonia, anastomotic leakage, and recurrent laryngeal nerve palsy occurred in 17.8%, 2.2%, and 6.7% of the patients, respectively. The multiple linear regression model revealed that a narrow upper mediastinum and greater blood loss during the thoracic procedure were significant factors associated with a prolonged thoracic operative time (P = 0.025 and P < 0.001, respectively). Upper mediastinal narrowing was not associated with postoperative complications. A narrow upper mediastinum was significantly associated with a prolonged thoracic operative time in patients with RAMIE.

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

Minimally invasive esophagectomy is the first-line approach for esophageal cancer; however, there has recently been a paradigm shift toward robotic esophagectomy (RE). We investigated the clinical outcomes of patients who underwent RE compared with those of patients who underwent conventional minimally invasive thoracoscopic esophagectomy (TE) for locally advanced cT3 or cT4 esophageal cancer using a propensity-matched analysis. Overall, 342 patients with locally advanced cT3 or cT4 esophageal cancer underwent transthoracic esophagectomy with total mediastinal lymph node dissection between 2018 and 2022. The propensity-matched analysis was performed to assign the patients to either RE or TE by covariates of histological type, tumor location, and clinical N factor. Overall, 87 patients were recruited in each of the RE and TE groups according to the propensity-matched analysis. The total complication rate and the rates of the three major complications (recurrent laryngeal nerve paralysis, anastomotic leakage, and pneumonia) were not significantly different between the RE and TE groups. However, the peak C-reactive protein concentration on postoperative day 3, rate of surgical site infection, and intensive care unit length of stay after surgery were significantly shorter in the RE group than in the TE group. No significant differences were observed in the harvested total and mediastinal lymph nodes. The total operation time was significantly longer in the RE group, while the thoracic operation time was shorter in the RE group than in the TE group. There was no significant difference between the two groups in the recurrence rate of oncological outcomes after surgery. RE may facilitate early recovery after esophagectomy with total mediastinal lymph node dissection and has the same technical feasibility and oncological outcomes as TE.

394. USEFULNESS OF INTRAOPERATIVE RECURRENT LARYNGEAL NERVE MONITORING IN REDUCING RECURRENT LARYNGEAL NERVE PARALYSIS AFTER ROBOT-ASSISTED THORACOSCOPIC ESOPHAGECTOMY

Abstract Background Robot-assisted thoracoscopic esophagectomy (RAMIE) is a precise and safe procedure with its advantages. On the other hand, RAMIE has several disadvantages. The lack of tactile function must be fully recognized, and surgical procedures must take the characteristics into account. We examined whether the findings obtained by intraoperative recurrent nerve monitoring (NIM) are useful in reducing recurrent laryngeal nerve paralysis (RLNP) after RAMIE. Methods Overall, 81 cases of RAMIE through February 2023 were included in the study. NIM was performed in 41 patients in the first term using a combination of continuous and intermittent methods (NIM group). In the subsequent 40 patients, NIM was not performed (non-NIM group) in order to confirm the learning effect of NIM and to shorten the operation time. RLNP was confirmed by a combination of symptoms and postoperative laryngoscopy. Clinical and oncological factors and short-term outcomes of the two groups were compared. Results All postoperative RLNP occurred on the left side. Six patients (14.6%) in the NIM group had Grade 1 or higher RLNP. The causes of RLNP were all found during thoracic manipulation; 4 cases of over-traction of RLN and 2 cases of crush injury by robotic forceps. There was a significant decrease in RLNP of Grade 2 or higher; 4 patients (9.7%) in the NIM group and 0 in the non-NIM group (p = 0.04). In the non-NIM group, there was a reduction in thoracic operative time, total operative time, and thoracic blood loss. Conclusion NIM made us aware of surgical maneuvers that cause RLNP after RAMIE. Although the proficiency of the RAMIE technique may have played a role in the reduction of RLNP in the later period, avoidance of risky surgical procedures due to the learning effect from the NIM was thought to have contributed to the decrease in RLNP.

Analysis of training pathway to reach expert performance levels based on proficiency-based progression in robotic-assisted minimally invasive esophagectomy (RAMIE).

Robotic-assisted minimally invasive esophagectomy (RAMIE) was first introduced in 2003 and has since then shown to significantly improve the postoperative course. Previous studies have shown that a structured training pathway based on proficiency-based progression using individual skill levels as measures of reach of competence can enhance surgical performance. The aim of this study was to evaluate and help understand our pathway to reach surgical expert levels using a proficiency-based approach introducing RAMIE at our German high-volume center. All patients undergoing RAMIE performed by two experienced surgeons for esophageal cancer since the introduction of the robotic technique in 2017 was included in this analysis. Intraoperative outcomes and postoperative outcomes were included in the analysis. The cumulative sum method was used to analyze how many cases are needed to reach expert levels for different performance characteristics and skill sets during robotic-assisted minimally invasive esophagectomy. From 06/2017 to 03/2022, a total of 154 patients underwent RAMIE at our facility and were included in the analysis. An advancement in performance level was observed for total operating time after 70 cases and for thoracic operative time after 79 cases. Lymph node yield showed an increase up until case 60 in the CUSUM analysis. Length of hospital stay stabilized after case 55. The CCI score inflection point was at case 55 in both CUSUM and regression analyses. Anastomotic leak rate stabilized at case 38 and showed another inflection point after case 83. Our data and analysis showed the progression from proficient to expert performance levels during the implementation of RAMIE at a European high-volume center. Further analysis of surgeons, especially with a different training status has yet to reveal if the caseloads found in this study are universally applicable. However, skill acquisition and respective measures of such are diverse and as a great range of number of cases was observed, we believe that the learning curve and ascent in performance levels cannot be defined by one parameter alone.

Experiences in reverse sequence esophagectomy: a promising alternative for esophageal cancer surgery

ObjectivesMcKeown esophagectomy is a standard and significant component of multimodality therapy in esophageal cancer, however, experience in switching the resection and reconstruction sequence in esophageal cancer surgery is not available. Here, we have retrospectively reviewed the experience of reverse sequencing procedure at our institute.MethodsWe retrospectively reviewed 192 patients who had undergone minimally invasive esophagectomy (MIE) with McKeown esophagectomy between August 2008 and Dec 2015. The patient’s demographics and relevant variables were evaluated. The overall survival (OS) and disease-free survival (DFS) were analyzed.ResultsAmong the 192 patients, 119 (61.98%) received the reverse sequence MIE (the reverse group) and 73 patients (38.02%) received the standard operation (the standard group). Both patient groups had similar demographics. There were no inter-group differences existed in blood loss, hospital stay, conversion rate, resection margin status, operative complication, and mortality. The reverse group had shorter total operation time (469.83 ± 75.03 vs 523.63 ± 71.93, p < 0.001) and thoracic operation time (181.22 ± 42.79 vs 230.41 ± 51.93, p < 0.001). The 5-year OS and DFS for both groups were similar (44.77% and 40.53% in the reverse group vs 32.66% and 29.42% in the standard group, p = 0.252 and 0.261, respectively). Similar results were observed even after propensity matching.ConclusionsThe reverse sequence procedure had shorter operation times, especially in the thoracic phase. The reverse sequence MIE is a safe and useful procedure when postoperative morbidity, mortality, and oncological outcomes are considered.

A novel nomogram for predicting the decision to delayed extubation after thoracoscopic lung cancer surgery

Objective Delayed extubation was commonly associated with increased adverse outcomes. This study aimed to explore the incidence and predictors and to construct a nomogram for delayed extubation after thoracoscopic lung cancer surgery. Methods We reviewed medical records of 8716 consecutive patients undergoing this surgical treatment from January 2016 to December 2017. Using potential predictors to develop a nomogram and using a bootstrap-resampling approach to conduct internal validation. For external validation, we additionally pooled 3676 consecutive patients who underwent this procedure between January 2018 and June 2018. Extubation performed outside the operating room was defined as delayed extubation. Results The rate of delayed extubation was 1.60%. Multivariate analysis identified age, BMI, FEV1/FVC, lymph nodes calcification, thoracic paravertebral blockade (TPVB) usage, intraoperative transfusion, operative time and operation later than 6 p.m. as independent predictors for delayed extubation. Using these eight candidates to develop a nomogram, with a concordance statistic (C-statistic) value of 0.798 and good calibration. After internal validation, similarly good calibration and discrimination (C-statistic, 0.789; 95%CI, 0.748 to 0.830) were observed. The decision curve analysis (DCA) indicated the positive net benefit with the threshold risk range of 0 to 30%. Goodness-of-fit test and discrimination in the external validation were 0.113 and 0.785, respectively. Conclusion The proposed nomogram can reliably identify patients at high risk for the decision to delayed extubation after thoracoscopic lung cancer surgery. Optimizing four modifiable factors including BMI, FEV1/FVC, TPVB usage, and operation later than 6 p.m. may reduce the risk of delayed extubation. Key Messages: This study identified eight independent predictors for delayed extubation, among which lymph node calcification and anaesthesia type were not commonly reported. Using these eight candidates to develop a nomogram, we could reliably identify high-risk patients for the decision to delayed extubation. Optimizing four modifiable factors, including BMI, FEV1/FVC, TPVB usage, and operation later than 6 p.m. may reduce the risk of delayed extubation.

Uniportal video-assisted thoracoscopic surgery esophagectomyoutcomes in 40 consecutive patients.

Minimally invasive esophagectomy has improved over time becoming faster and less invasive. We have changed our technical approach from multiportal to uniportal video-assisted thoracoscopic surgery (VATS) esophagectomyover the years. In this study, we analysed our results with uniportal VATS esophagectomytechnique. This study was a retrospective analysis of 40 consecutive patients with the intent to perform uniportal VATS esophagectomyfor esophagealcancer between July 2017 and August 2021. Demographic criteria, comorbidities, neoadjuvant therapy, intraoperative data, complications, length of stay, pathological data, 30- and 90-day mortality and 2-year survival data were recorded. Forty patients (21 female) were operated (median age 62.9 [53.5-70.25]). Eighteen patients (45%) received neoadjuvant chemoradiation. The chest part of all cases was started with uniportal VATS and 31 (77.5%) was completed uniportally (34 Ivor Lewis, 6 McKeown). The median thoracic operation time in minimally invasive Ivor Lewis esophagectomywas 90 min (77.5-100). The median time for uniportal side-to-side anastomosis was 12 min (11-16). Five (12.5%) patients had leak, and 4 were intrathoracic. Twenty-eight (70%) patients had squamous cell carcinoma, 11 adenocarcinoma and 1 squamous cell carcinoma with sarcomatoid differentiation. Thirty-seven (92.5%) patients had R0 resection. The mean number of lymph nodes dissected was 24 ± 9.5. Thirty- and ninety-day mortality was 2.5% (n = 1). The mean follow-up was 44 ± 2.8 months. Two-year survival was 80%. Uniportal VATS esophagectomyis a safe, fast and feasible alternative to other minimally invasive and open approaches. Comparable results to contemporary series are observed in perioperative and oncologic outcomes.

Two-rope method for dissecting esophagus in McKeown MIE.

Minimally invasive McKeown esophagectomy (McKeown MIE) is performed at many hospitals in esophageal cancer(EC) treatment. However, secure and quick methods for dissecting the esophagus and dissecting lymph nodes in this surgery are lacking. This study introduces a simple, secure and feasible esophagus dissecting technique named two-rope method. Two mobile traction ropes are placed around the esophagus and we tow these ropes to free the esophagus, dissect the lymph nodes, and decrease the operative trauma. Retrospective analysis was performed on 112 patients who underwent McKeown MIE in our center from January 2019 to September 2021. They were assigned into two groups based on the method of dissecting the esophagus: Group A (two-rope method, 45 cases) and Group B (regular method, 67 cases). Operation time, thoracic operation time, the number of dissected thoracic lymph nodes, and postoperative complications were compared between the two groups after propensity score matching. Using 1:1 nearest neighbor matching, we successfully matched 41 pairs of patients. Operation time, thoracic operation time, and the duration (ac to as) was significantly shorter and the size of the abdominal incision was significantly smaller in the Group A than Group B (p < 0.05). There was no statistically significant difference in the number of dissected thoracic lymph nodes, pulmonary infection, anastomotic leak, recurrent laryngeal (RLN) injury, and chylothorax between the two groups (p > 0.05). Two-rope method to free the esophagus and dissect thoracic lymph nodes in McKeown MIE has significant advantages compared with the regular method. The technique is, therefore suitable for widespread adoption by surgeons.

Will robot-assisted minimally invasive esophagectomy improve patient outcomes compared to conventional minimally invasive esophagectomy?

Aim: To determine if introducing a standardized minimally invasive esophagectomy (MIE) to robot-assisted MIE (RAMIE) improves the short-term patient outcomes. Methods: A total of 292 patients with esophageal cancer underwent thoracic esophagectomy [MIE (n = 208); RAMIE (n = 84)] at Aichi Cancer Center Hospital between January 2019 and August 2022. The cumulative sum (CUSUM) method was used to analyze the learning curve for RAMIE. The MIE and RAMIE surgical and postoperative outcomes were also analyzed retrospectively. Propensity score matching was used to compensate for the selection bias. Results: The CUSUM plot of the console time reached a plateau in the 29th case and began to decrease in the 43rd case. Therefore, we defined phase I (introductory phase) up to the 28th case, phase II from the 29th - 42nd case, and phase III from the 43rd case onward. The median thoracic operative time was significantly longer in the RAMIE group than the MIE group in phase I (P &lt; 0.001); however, the median RAMIE console time was 227.5, 212, and 182 min in phases I-III, respectively, compared to a median MIE thoracic operative time of 232 min. The incidence of recurrent laryngeal nerve (RLN) palsy was significantly less after phase II for RAMIE (12.5%) compared to MIE (25%; P = 0.04). The incidence of RLN palsy was also decreased in phases II and III for RAMIE after matching (13%; P = 0.04). Conclusion: Standardization of RAMIE may decrease the incidence of RLN palsy in patients compared to MIE.

SJLA_2024_A7: Five Cases of Salvage Thoracoscopic Esophagectomy after Proton Beam Therapy

Introduction: Proton beam therapy (PBT) has the feature of reducing radiation exposure to surrounding organs compared to conventional X-ray irradiation, so PBT for esophageal cancer is gradually spreading. Background: However, there are few reports about salvage esophagectomy after PBT, and its efficacy and safety are unclear. Methods: We reviewed the clinical and surgical outcomes of 5 cases who underwent salvage thoracoscopic esophagectomy after PBT from 2010 to 2023. Results: Four of five cases were males; the median age was 70 years, and all lesions were in the thoracic esophagus. One case was T2 lesion depth before PBT and 4 cases were T3. The median dose of proton beam radiation was 35.2 (26–60) Gy, and the median total (including X-ray) radiation dose was 66 (40–71.2) Gy. For of them were recurrent and one was remnant lesions. All cases were performed through thoracoscopic esophagectomy (one was converted to open surgery). Median thoracic operation time and blood loss were 217 (213–427) min and 10 (6–565) ml, respectively. Two cases with a preoperative diagnosis of T1-2 showed fibrosis comparable to that seen in conventional salvage esophagectomy, and we underwent R0 resection. However, the others had severe fibrosis and Grade IIIb postoperative complications such as thoracic abscess and cardiac tamponade requiring open chest drainage, and percutaneous pericardial drainage was occurred in two cases who underwent R2 resection. Discussion: For the nonlocally advanced cases, the results were comparable to the conventional salvage esophagectomy. However, fibrosis and scarring of the irradiated area were stronger after PBT, especially in advanced lesions, and they were at high risk for non-R0 resection and complications. Conclusion: Because the number of cases was small in this study, it is necessary to conduct further studies on a large number of cases, including multicenter collaboration.

Impact of Robot-Assisted Minimally Invasive Esophagectomy for Esophageal Cancer: A Propensity Score-Matched Short-Term Analysis.

We compared short-term clinical outcomes between robotic-assisted minimally invasive esophagectomy (RAMIE) and video-assisted thoracic esophagectomy (VATS-E) using propensity score-matched analysis. We enrolled 114 patients with esophageal cancer who underwent esophagectomy at our institution from January 2013 to January 2022. Propensity score matching was performed to minimize selection bias between the RAMIE and VATS-E groups. After propensity score matching, 72 patients (RAMIE group, n = 36; VATS-E group, n = 36) were selected for analysis. No significant differences in clinical variables were observed between the two groups. The RAMIE group had a significantly longer thoracic operation time (313 ± 40 vs. 295 ± 35 min, P = 0.048), a higher number of right recurrent laryngeal nerve lymph nodes (4.2 ± 2.7 vs. 2.9 ± 1.9, P = 0.039), and a shorter postoperative hospital stay (23.2 ± 12.8 vs. 30.4 ± 18.6 days, P = 0.018) than the VATS-E group. The RAMIE group tended to have a lower rate of anastomotic leakage (13.9% vs. 30.6%) than the VATS-E group, although the difference was not statistically significant (P = 0.089). No significant differences were found in recurrent laryngeal nerve paralysis (11.1% vs. 13.9%, P = 0.722) or pneumonia (13.9% vs. 13.9%, P = 1.000) between the RAMIE group and the VATS-E group. Although RAMIE for esophageal cancer requires a longer thoracic surgery time, it might be a feasible and safe alternative to VATS-E for treating esophageal cancer. Further analysis is needed to clarify the advantages of RAMIE over VATS-E, especially in terms of long-term surgical outcomes.

Prone position thoracoscopic-assisted total mesoesophageal excision: initial experiences and benefits of lymph node dissection.

Total mesoesophageal excision (TME) is a promising procedure. Prone position thoracoscopic-assisted TME might be a good choice, even without robust evidence yet. Therefore, it is necessary to explore the safety and efficacy of this procedure. We retrospectively analyzed the short-term outcomes regarding intraoperative unplanned events, postoperative complications, and lymphadenectomy in 61 patients who underwent prone position thoracoscopic-assisted TME from June, 2020 to August, 2021. The learning curve was also defined. Of these sixty-one patients, there were 10, 24 and 27 cases of tumor in the upper, middle, and lower thoracic, respectively. Although there were five cases of unplanned events during surgery, no conversion to thoracotomy occurred. The median thoracic operation time was 113(43-161) minutes, R0 resection rate was 93.4% (57/61), and negative circumferential resection margin rate was 96.7% (59/61). Median overall lymph node dissection was 21(9-47), with 13(5-41) thoracic lymph node dissection. Incidence of postoperative pulmonary complications, cardiovascular complications, and leakage were 9.8%, 3.3%, and 9.8%, respectively, with no death within 30days after operation. The positive rate of middle and lower mediastinal lymph nodes was 1.1%, 3.5%, and 2.4% for upper, middle, and lower tumors, and 5.5%, 1.8%, and 1.3% for pT3-4, pT2, and pT1 patients. Learning curve showed that 36 cases are the best cut-off value for proficiency of prone position thoracoscopic-assisted TME. The prone position thoracoscopic-assisted TME is a safe procedure that is more conducive to thoracic lymph node dissection, especially for middle and lower mediastinum.

254. TODAY’S ISSUES IN ROBOT-ASSISTED ESOPHAGECTOMY

Abstract Recently, effectiveness of robot-assisted minimally invasive esophagectomy (RAMIE) has been reported however, there are some issues specific to RAMIE which may lead to major complications. The issues include 1) interference with the right shoulder, 2) compression of vertebral bodies and blood vessels, 3) energy devices, and 4) education to young surgeons. In this study, we evaluated the short-term outcome of RAMIE in our department, and show the ideas for improving those issues. For 1), the assistant gives instructions to the surgeon, and uses a protector on right shoulder. In 2), port arrangement depending on the cases and switching the camera port is useful. 3) Because those devices are still under developing, careful procedure is required while using energy device, 4) Double console and extra thoracoscopic camera is useful in operating under the education. We conducted a comparative study of 81 cases of RAMIE performed at our institution from 2014 to January 2022 and 392 cases of prone thoracoscopic esophagectomy performed at about the same time, to evaluate the short-term outcomes including complications. RAMIE showed an increase in thoracic operation time (median 286 min vs 260 min), but amount of thoracic bleeding tended to be smaller (median 13 mL vs 19 mL). Recurrent laryngeal nerve palsy (G1) was about 40%, and pneumonia was about 18%, which was about the same. One case encountered to in-hospital death from RAMIE group by aspiration pneumonia and one cardiac tamponade by thoracoscopic surgery, respectively, Also, there was no difference in short-term outcomes between experienced and non-experienced surgeons, except operation time. It is difficult to educate young surgeons who cannot afford to pay attention to the surroundings because there is a possibility that the surrounding organs will be damaged without resistance. Therefore, experienced surgeon should observe and understand the situation using double console or an additional scope. Also, many other knacks and tricks are important to reduce the complications arises from robotic surgery.

417. ROBOT-ASSISTED MINIMALLY INVASIVE ESOPHAGECTOMY WITH UPPER MEDIASTINAL LYMPHADENECTOMY

Abstract We started robot-assisted minimally invasive esophagectomy (RAMIE) in 2012 using da Vinci S. After the reimbursement in the national insurance system in 2018, RAMIE has been indicated as an institutional standard surgery simply depending on the da Vinci availability. Our early series of 45 RAMIEs showed significantly less postoperative morbidity (p = 0.03) mainly due to less pulmonary complication (p = 0.006) compared to conventional minimally invasive esophagectomy using propensity score matching (Ann Surg Oncol. 2020). This study aims to retrospectively evaluate the feasibility of RAMIE and to demonstrate our standardized RAMIE with updated data. Our surgical technique is as follows. A patient is placed in a prone position with both lung ventilation with 8-10 mmHg artificial pneumothorax. In the upper mediastinum, the thoracic duct is usually preserved unless there is tumor invasion. Then, the tracheoesophageal arteries flowing into the visceral sheath over the recurrent laryngeal nerve (RLN) are divided first and RLN is isolated laterally. Then, the lymphatic tissue is dissected from the trachea. This procedure is identical on both sides of RLN nodal dissection. By January 2022, 89 RAMIEs (S: 6 cases and Xi: 83 cases) were performed. Thoracic operation time was 348 min and console time was 296 min. Intraoperative blood loss was 80 g and the number of harvested thoracic nodes is 23. There was no conversion from RAMIE to MIE nor to open procedure. Overall severe postoperative morbidity (Clavien-Dindo Grade 3 or higher) was 17% (15/89) and clinically relevant postoperative recurrent laryngeal nerve palsy (Clavien-Dindo Grade 2 or higher) was 10% (9/89). There was no postoperative mortality. RAMIE was safe and feasible.

Semiprone thoracoscopic approach during totally minimally invasive Ivor-Lewis esophagectomy seems to be beneficial.

Minimally invasive Ivor-Lewis Esophagectomy (MIE) is widely accepted as a surgical treatment of resectable esophageal cancer. Aim of this paper is to describe the surgical details of our standardized MIE technique and its safety. We also evaluate the esophageal mobilization in semiprone compared to the left lateral position. A retrospective analysis of 141 consecutive patients who underwent Ivor-Lewis esophagectomy for cancer, from February 2016 to September 2021, was conducted. All the procedures were performed by totally thoraco-laparoscopic with an intrathoracic end-to-side circular stapled anastomosis. Thoracic phase was performed in left lateral position (LLP-group, n=47) followed by a semiprone position (SP-group, n=94). The intraoperative and postoperative outcomes were prospectively collected and analyzed. The procedure was completed without intraoperative complication in 94.68% of cases in SP-group and in 93.62% of cases in LLP-group (P=0.99). The total operative time and thoracic operative time were significantly shorter in SP-group (P=0.0096; P=0.009). No statistically significant differences were detected in postoperative outcomes between the groups, except for anastomotic strictures (higher in LLP-group, P=0.02) and intensive care unit stay (longer in LLP-group, P=00.1). No reoperation was needed in any cases. Surgical radicality was comparable; the median of harvested lymph nodes was significantly higher in SP-group (P<0.0001). The present semiprone technique of thoraco-laparoscopic Ivor-Lewis esophagectomy is safe and feasible but may also provide some advantages in terms of lymph nodes harvested and total operation time.

A novel nomogram predicting the risk of postoperative pneumonia for esophageal cancer patients after minimally invasive esophagectomy.

Pneumonia is a common complication after minimally invasive esophagectomy (MIE), which prolongs hospital stay, adding to the cost and increasing the risk to patients' lives. This study aimed to identify risk factors and establish a predictive nomogram for postoperative pneumonia (PP). This case control study included 609 patients with esophageal cancer who underwent MIE between March 2015 and August 2019 in Cancer Hospital, Chinese Academy of Medical Sciences. We randomly divided the data into training and validation sets in the ratio of 7:3 and performed univariate and multivariate logistic regression analyses to acquire independent risk factors of the training set. We constructed a nomogram based on the independent risk factors. The concordance index (C-index), receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA) plots were used to evaluate the discrimination of the nomogram. Validation set was applied to confirm the predictive value of the nomogram. In the univariate analysis, age, gender, abdominal procedure method, thoracic operative time, duration of chest tube placement, anastomotic leakage, and recurrent laryngeal nerve palsy were found to be correlated with the incidence of PP. In multivariate analysis, all variables except thoracic operative time were found to be independent risk factors for PP. A nomogram was constructed based on these independent risk factors. The C-index of the training and validation sets was 0.769 and 0.734, respectively, and the areas under the curve (AUC) of ROC curves of the training and validation sets were 0.769 and 0.686, respectively. The calibration plots and DCA plots of the training and validation sets showed the accuracy and predictive value of the nomogram. The nomogram could accurately identify the risk factors for PP. We could predict the occurrence of PP based on this nomogram and take corresponding measures to reduce the incidence of PP.

668 USEFULNESS OF PRONE-POSITION COMPUTED TOMOGRAPHY AS PREOPERATIVE SIMULATION OF THORACOSCOPIC ESOPHAGECTOMY FOR THORACIC ESOPHAGEAL CANCER

Abstract The study aimed to evaluate the usefulness of prone-position computed tomography (CT) for predicting relevant thoracic procedure outcomes in minimally invasive esophagectomy (MIE) for thoracic esophageal cancer. Methods A total of 59 patients underwent esophagectomy between May 2019 and December 2020 in Tokai University Hospital. Preoperative CT imaging was conducted with the patient in both the supine and prone positions, and the magnitude of change in the intramediastinal space was calculated. In the 56 patients (94.9%) who had undergone MIE, the effects of such a difference on the surgical outcomes were analyzed. Results A significant correlation of the magnitude of change in VE (distance between ventral aspect of vertebral body and the midpoint of esophagus) with the surgical outcome was revealed in the 17 patients (30.4%) in whom the magnitude of change in VE was over the 75th percentile. That is, in this subgroup, VE showed a negative correlation with the thoracic operation time (p = 0.01) and blood loss during the thoracic procedure (p = 0.01). Multivariate analysis identified a magnitude of change in VE □9 mm as an independent risk factor for postoperative pneumonia. Conclusion This study indicates that preoperative prone-position CT imaging is useful for predicting the level of ease or difficulty of securing an adequate operative field, surgical outcomes, and the risk of postoperative pneumonia in MIE.

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.