Recurrent Laryngeal Nerve Palsy Research Articles

Dissection of the lymph nodes along the recurrent laryngeal nerve in robotic esophagectomy

Lymph node (LN) metastasis serves as a pivotal prognostic determinant in esophageal cancer, particularly in cases of squamous cell carcinoma (SqCC). The involvement of LN metastasis frequently extends to the LNs along the recurrent laryngeal nerve (RLN). Radical dissection of these nodes is imperative for precise staging and the prevention of loco-regional recurrence. Historically, the emphasis on RLN node dissection has been evident in numerous literature, establishing it as a mandatory procedure in different countries. Nevertheless, the risk of RLN palsy following such dissection is a substantial concern, given its association with significant postoperative complications and long-term implications for quality of life. Recent literature has highlighted RLN node dissection in robotic surgery, demonstrating favorable outcomes in comparison to alternative surgical modalities. This review paper aims to comprehensively assess prior publications on this subject, elucidating the outcomes and implications of RLN node dissection in robotic esophagectomy (RE).

Recurrent laryngeal nerve lymph node dissection with subcomplete sealing using advanced bipolar energy device in minimally invasive esophagectomy.

Recurrent laryngeal nerve (RLN) palsy is a complication that must be avoided during esophagectomy. While RLN injury is thought to be caused by thermal spread from electric devices, electric devices are useful to avoid bleeding. When dissecting lymph nodes around RLNs, to seal small vessels, we use subcomplete technique with advanced bipolar. We describe our surgical technique, termed the subcomplete sealing technique, in RLN lymph node dissection. The first step is to perform blunt dissection with forceps on both sides of the esophageal branch near the right RLN. A distance of at least 2 mm from the RLN was preferred. Sealing with advanced bipolar often causes tissue shrinkage, pulling the RLN near the device. To prevent this, sealing should be stopped before reaching completion. Although the sealing was not complete, it was sufficient to seal the small vessels. After subcomplete sealing, the sealed tissues were dissected using laparoscopic scissors. The lymph nodes around left RLN are dissected in the same manner. A total of 76 patients received esophagectomy with the subcomplete technique. Grade IIIa RLN palsy occurred in three cases (3.95%). Over Grade IIIb RLN palsies did not occur. This subcomplete sealing technique can assist surgeons in performing RLN lymph node dissection without bleeding and increasing the rate of RLN palsy.

Peak expiratory flow predicts the occurrence of postoperative pneumonia after esophagectomy for esophageal cancer.

Expiratory flow is an important factor in the achievement of airway clearance that is required to prevent postoperative pneumonia (POP). Although peak expiratory flow (PEF) has been shown to predict the occurrence of POP in lung cancer patients after lobectomy, its predictive power in relation to esophagectomy for esophageal cancer remains unknown. This study assesses PEF as a predictor of POP in patients with esophageal cancer undergoing radical esophagectomy. We conducted a single-center, retrospective cohort study of patients who underwent radical esophagectomy with gastric tube reconstruction at our institution between January 2007 and December 2022. Preoperative pulmonary functions, including PEF, were assessed before surgery. Additionally, POP was diagnosed as a Clavien-Dindo classification of Grade II or higher. Survival and pneumonia incidence were compared using the Kaplan-Meier method. Logistic regression analysis was used to examine the relationship between these variables and POP. The study included 513 patients, of which 441 were men. POP occurred in 86 patients (16.7%). When all patients were stratified by %PEF into two groups, the group with %PEF lower that 80% had significantly poorer prognosis and higher incidence of pneumonia. Multivariable logistic regression analysis indicated that %PEF (OR: 0.986, 95%CI: 0.974-0.999, P = 0.030), along with age, BMI, preoperative treatment, and recurrent laryngeal nerve palsy were independent protective factors against POP. These results reveal that %PEF predicts the development of POP following esophagectomy for esophageal cancer.

Robot-assisted minimally invasive esophagectomy for esophageal cancer in the left lateral decubitus position.

The use of robot-assisted minimally invasive esophagectomy (RAMIE) in the prone position for esophageal cancer has been currently increasing worldwide. In future, as surgical-assisted robots become more widespread, it is estimated that only two methods of transthoracic approach will remain: RAMIE and open thoracotomy for thoracic esophageal cancer. RAMIE in the left lateral decubitus position (RAMIE-LLDP) has the same field of view as open thoracotomy, is safe in emergency situations, and provides education on open thoracotomy. Between September 2020 and April 2024, RAMIE-LLDP was performed in 64 consecutive patients with esophageal cancer. RAMIE-LLDP was performed with the operating table rotated and tilted 45° to the ventral side under artificial pneumothorax. The hand-control setting of the surgical-assist robot system was reversed left to right when the Patient Cart was rolled from the same direction as the RAMIE in the prone position. The mean total surgery and console times during the thoracic procedure were 254-min overall and 225min in the last 24 cases and 195-min overall and 178-min in the last 24 cases, respectively. The mean amount of blood loss was 203.4g overall and 28.3g in the last 24 cases. Postoperative recurrent laryngeal nerve palsy with Clavien-Dindo classification (CD) was ≥ 2 in six patients (9.4%). Postoperative pneumonia with CD ≥ 2 was observed in 11 patients (17.2%). Conversion to open thoracotomy was observed in three patients (4.7%). In all three patients, an immediate conversion to thoracotomy without patients' position change was actually possible and no serious complications were noted. No mortality occurred within 30days postoperatively. RAMIE-LLDP which facilitates emergency thoracotomy has perioperative results comparable to those of conventional thoracoscopic esophagectomy and is educational for open surgery. RAMIE-LLDP is the safest and most optimal surgery for esophageal cancer.

A prospective observational study on the anatomical variations of recurrent laryngeal nerve and its application in the prevention of injury during thyroid surgery in a tertiary care centre

BackgroundThyroid gland is the largest and most vascular structure among the endocrine glands. The recurrent laryngeal nerve and the superior laryngeal nerve are closely related to the thyroid gland; these nerves control voice and are vital in breathing. Anatomical preservation of the recurrent laryngeal nerve (RLN) is the gold standard in thyroid surgery. Visual identification of RLN has decreased the rates of permanent RLN palsy during thyroid and parathyroid operations. Prior knowledge about the branching patterns will help in predicting and preventing injury to the nerve during thyroid surgery.Aim and objectivesThe aim of the study is to observe the terminal branching pattern of recurrent laryngeal nerve before its entry into the larynx.MethodsAn observational study with 50 participants who fulfilled the inclusion and exclusion criteria were enrolled in the study. After a complete evaluation and pre-anaesthetic checkup, the patients were operated and intraoperative findings of RLN branching were recorded and compared for the study.ResultsIn our study, out of the 50 patients who underwent thyroid surgery during the course of the study, right-sided RLN branching was demonstrated in 25 patients (21 right hemithyroidectomy and 4 total thyroidectomy). Ten patients had RLN bifurcation, 7 had trifurcation, 5 had numerous branches, and 3 with no branching pattern were noted. Similarly, out of 29 patients (25 left hemithyroidectomy and 4 total thyroidectomy) in whom left-sided RLN branching was studied, bifurcation was seen in 10 patients, trifurcation in 12 patients, and multiple branching was observed in 7.ConclusionThe anatomical variations seen in RLN may increase the risk of vocal cord palsy due to its injury. Anatomical variations are categorized according to the original direction of the RLN and the number of terminal branches in the larynx. This classification aids in the identification and preservation of its branches, hence facilitating a safer thyroidectomy.

Implication of surgical loupes on complications following thyroidectomy: a meta-analysis.

To determine the effectiveness of surgical loupes in reducing postoperative RLN palsy and hypocalcemia following thyroidectomy. PubMed, Scopus and Google Scholar databases were searched between 2000 and 2024. Studies were included if they reported at least one complication outcome following thyroidectomy using surgical loupes. The outcome measure was the log odds ratio, with negative log odds indicating results favouring the experimental group. The model utilized the DerSimonian-Laird estimator, and Wald-type tests. The qualitative data synthesis included 813 patients from 6 included studies, including 410 patients with surgical loupes and 403 patients without surgical loupes. There was a statistically significant reduction in the rate of temporary RLN palsy in the surgical loupe group log(OR) = - 0.87 [(- 1.58, - 0.15), DL (Dersimonian and Laird method), REM (random effects model), CI (confidence interval) = 95%], or a 41.8% lower probability. The rates of permanent RLN palsy log(OR) = - 0.31 [(- 1.45, 0.82), DL, REM, CI = 95%], temporary hypocalcemia log(OR) = - 0.34 [(- 1.25, 0.57), DL, REM, CI = 95%], and permanent hypocalcemia log(OR) = - 0.85 [(- 2.24, 0.54), DL, REM, CI = 95%] were not statistically significant between the two groups, although there were trends toward decreases in these rates in the loupes group. Surgical loupe use during thyroidectomy can lead to a 41.8% lower probability of temporary RLN palsy compared to operating without loupes. 3a.

Application of modified spiral tracheoplasty in thyroid carcinoma with trachea invasion: a retrospective analysis of 15 cases

BackgroundTo describe the indications, techniques and preliminary experience of modified spiral tracheoplasty in the reconstruction of large tracheal defect after thyroidectomy.MethodsThe medical records of patients who underwent tracheal torsion to repair large tracheal defects after thyroid carcinoma surgery from January 2019 to January 2022 were retrospectively reviewed. The extent of tracheal defect, duration of tracheal reconstruction, postoperative complications and surgery results were analyzed.ResultsThe duration of tracheal reconstruction was 30–60 min. No postoperative bleeding, incision infection, tracheostomy stenosis occurred. Recurrent laryngeal nerve palsy occurred in 5 patients. All patients were followed up for 24 to 60 months. The 2-year overall survival rate was 100%, the 2-year local control rate of trachea was 100%, and the 2-year tumor-free survival rate was 81.8%.ConclusionThe modified spiral tracheoplasty is a safe and effective method to repair the large defect of trachea after thyroid carcinoma invading the trachea.

Delayed-onset vocal cord palsy after thyroidectomy occurring despite normal initial post-operative endoscopy.

Recurrent laryngeal nerve (RLN) injury is a known complication of thyroidectomy. Most cases manifest immediately and are promptly recognized. Rarely, some patients experience delayed-onset vocal cord palsy. This can occur despite normal findings on intra-operative nerve monitoring and initial post-operative endoscopy. This can cause considerable distress for patients, and its incidence and prognosis should be recognized. We report seven patients experiencing delayed-onset RLN palsy (RLNP) after thyroidectomy. All had normal findings on pre-operative flexible nasoendoscopy (FNE), intra-operative nerve monitoring at conclusion of surgery, and initial post-operative FNE. All diagnoses of RLNP were confirmed on endoscopy. Serial FNE examinations were performed to evaluate recovery. Of seven patients (43% male, median age 65 years), the median timing of delayed-onset RLNP was 12 (range 9-35) days. RLNP was diagnosed on the unilateral side of surgery in six out of seven patients (86%). All received conservative management, including referral to voice therapy. All seven patients recovered vocal cord function after a median duration of 24 weeks (range 8-52 weeks), and six within ~6 months (28 weeks). The incidence of this complication was 0.1% (among 6607 thyroidectomies). We report the first Australian series of delayed-onset vocal cord palsy after thyroidectomy. We explore its prognosis, discussing different pathophysiological mechanisms and the timeframe for recovery compared to most other RLN injuries. This may assist recognition of a rare complication, reassure patients, and facilitate early intervention to improve a patient's quality of life.

Characteristics of lymph node metastasis and short-term outcome of esophageal squamous-cell carcinoma undergoing minimally invasive esophagectomy: a prospective cross-sectional study (with video)

Introduction: Surgery for esophageal squamous-cell carcinoma (ESCC) presents many potential challenges owing to malignant lymph node metastasis, complex procedures and severe postoperative complications. The appropriate lymphadenectomy for ESCC remains controversial. This study aims to evaluate the characteristics of lymph node metastasis and postoperative complications in patients with ESCC undergoing minimally invasive esophagectomy and extended two-field lymph node dissection. Patients and methods: This prospective, single-center, cross-sectional study was conducted from October 2022 to May 2024. All patients with ESCC who underwent minimally invasive esophagectomy and extended two-field lymph node dissection were selected for this study. Postoperative lymph nodes were divided into upper thoracic, middle thoracic, lower thoracic and abdominal lymph node groups. Results: Seventy-four patients with ESCC, including 49 patients who underwent upfront surgery and 25 patients who received preoperative chemoradiotherapy, were selected. The rate of lymph node metastasis in all patients was 39.2%, with 13.6% of patients having upper thoracic metastasis. The factors affecting the rate of lymph node metastasis included preoperative chemoradiotherapy, tumor stage, poor differentiation, lymphovascular/perineural invasion, and tumor size greater than 2 cm, all of which were significantly different (P<0.05). Common postoperative complications included pneumonia (25.7%), recurrent laryngeal nerve (RLN) palsy (10.8%) and anastomotic leak (4.1%). There were no cases required conversion to open surgery, nor any deaths within 90 days postoperatively. Conclusion: Lymph node metastasis in esophageal squamous-cell carcinoma has a high incidence, occurs in the early stages, and is widely distributed in all regions of the mediastinum and abdomen. Minimally invasive esophagectomy and extended two-field lymph node dissection are feasible and safe, with low complication rates.

The effect of local injections of a vitamin d receptor activator into the parathyroid glands on the level of parathyroid hormone and mineral metabolism in patients with secondary hyperparathyroidism in chronic kidney disease

Aim: to assess the dynamics of laboratory parameters (total calcium, inorganic phosphorus, albumin, and alkaline phosphatase levels) and parathyroid hormone (PTH) concentrations after administrating local injections of vitamin D receptor activators into the parathyroid glands of patients with secondary hyperparathyroidism in chronic kidney disease. The intial PTH concentration ranged from 300 to 600 pg/ml. This range was chosen to explore a more active strategy for managing the disease at its early stages and preventing the induction and progression of cardiovascular complications associated with secondary hyperparathyroidism.Methods: the study included 48 patients diagnosed with end-stage of chronic kidney disease, who were treated in the nephrology and dialysis department. The main group consisted of 34 patients who received two consecutive injections of a vitamin D receptor activator (Paricalcitol) into the most enlarged and technically accessible parathyroid gland under ultrasound guidance. The control group included 14 patients who continued with conservative treatment due to technical infeasibility of performing the injections. Effectiveness was assessed by comparing laboratory parameters before the intervention and six months after the injections in the main group, and among patients continuing standard medical therapy for secondary hyperparathyroidism.Results: the results showed a statistically significant reduction in parathyroid hormone levels after 3 and 6 months of treatment. In the control group, which continued to receive standard drug therapy, PTH and blood phosphate levels continued to rise. No undesirable effects or complications, such as hypocalcemia, bleeding, allergic reactions, and recurrent laryngeal nerve paralysis, were not observed throughout the observation period.Conclusion: this research confirms the efficacy of local injections of vitamin D receptor activators (Paricalcitol) in reducing PTH levels without significant complications or changes in calcium levels. This method could be employed to correct and prevent secondary hyperparathyroidism complications in early stages among patients with end-stage chronic kidney disease, offering a safer and more effective treatment option.

Determinants of Neurological Outcome Following Elective and Emergency Open Thoracoabdominal Aortic Aneurysm Repair-A Retrospective Multi-Center Study.

Background/Objectives: This study aimed to evaluate and establish the incidence of all types of neurological complications at our high-volume reference center for open TAAA repair in the Netherlands and Germany. Additionally, we sought to identify predictors for various neurological complications. Methods: This retrospective study was conducted in accordance with the STROBE guidelines, with the aim of reporting neurological outcomes for all patients who underwent open thoracoabdominal aortic aneurysm repair at two centers (Maastricht-Aachen) from 2000 to 2023, and to examine the association between these outcomes and pre- and perioperative parameters. The primary endpoints of the study were all-cause mortality, spinal cord ischemia (SCI), stroke, intracerebral bleeding (ICB), critical illness polyneuropathy/myopathy (CIP/CIM), and recurrent laryngeal nerve paralysis. Results: A total of 577 patients were operated on for open TAAA repair in two centers. The total in-hospital mortality rate was 20.6%, while the elective cases in-hospital mortality rate was 14.6%. In all, 28.2% of patients experienced neurological complications. The spinal cord ischemia rate was 7.5%, intracerebral bleeding 3.6%, stroke 5.9%, critical illness polyneuropathy 3.5%, and laryngeal nerve paresis 5.7%. Crawford extent II was significantly associated with increased neurological complications (OR 2.05, 95% CI 1.39-3.03, p = 0.003), while Crawford extent III and IV were significantly associated with fewer postoperative neurological complications (OR 0.61 (0.38-0.98) p = 0.04) (OR 0.52 (0.30-0.92) p = 0.02). Preoperative ASA score > 3 (OR 1.76, 95% CI 1.16-2.67, p = 0.007), COPD (OR 1.82, 95% CI 1.19-2.78, p = 0.006), massive intraoperative transfusion (OR 1.48, 95% CI 1.01-2.17, p = 0.04), and reinterventions during hospital stay (OR 1.98, 95% CI 1.36-2.89, p < 0.001) and surgery time (p =< 0.001) were significantly associated with neurological complications. Patients with neurological complications had higher rates of other postoperative morbidities. Conclusions: Neurological complications after open TAAA repair remain a significant concern, with identified risk factors associated with increased morbidity, mortality, and resource utilization. Identifying at-risk patients could potentially lead to a reduction in neurological complications.

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

Cervical esophagogastric anastomosis is conventionally performed using the McKeown esophagectomy. However, an optimal anastomotic technique has not yet been established. This study aimed to compare the clinical outcomes of triangular anastomosis (TA) and totally mechanical Collard anastomosis (TMCA) for cervical esophagogastric anastomosis during minimally invasive esophagectomy with gastric conduit reconstruction through the retrosternal route. In this matched- cohort study, 117 patients who underwent minimally invasive esophagectomy between 2019 and 2024 were divided into TA and TMCA groups. The TA technique was performed between September 2019 and December 2021, and the TMCA technique was performed between January 2022 and January 2024. We then compared the surgical outcomes and postoperative complications (pneumonia, recurrent laryngeal nerve palsy, anastomotic leakage, and stricture) between the two groups. Propensity score matching revealed that 40 patients were included in both the TA and TMCA groups. The rates of pneumonia, recurrent laryngeal nerve palsy, and anastomotic leakage were not significantly different between the two groups. However, the rate of anastomotic stricture was lower in the TMCA than in the TA group (2.5% vs. 27.5%, respectively, P = 0.003). Compared with the TA technique, the TMCA technique reduced the rate of anastomotic stricture when performing cervical esophagogastric anastomosis during minimally invasive esophagectomy with gastric conduit reconstruction through the retrosternal route.

Safety and Efficacy of Conversion Therapy After Systemic Chemotherapy in Advanced Esophageal Cancer with Distant Metastases: A Multicenter Retrospective Observational Study.

Patients with esophageal squamous cell carcinoma (ESCC) with distant metastasis were treated with systemic chemotherapy. Recent advances in multimodal treatments have made conversion therapy a viable option for patients with incurable ESCC. We aimed to assess the safety and efficacy of conversion therapy for ESCC with distant metastases. Conversion therapy was defined as surgery or chemoradiotherapy (CRT) used to cure tumors that were previously considered incurable because of distant metastasis. We conducted a retrospective review of patients who underwent ESCC conversion therapy and assessed the treatment outcomes, including adverse events and survival rates. A total of 147 patients from 22 institutions were included. Systemic chemotherapy was initially administered to all patients. The most common M1 factor was the para-aortic lymph node, accounting for 55% of cases. Following the initial treatment, 116 patients underwent surgery, with 31 receiving CRT as conversion therapy. Postoperative complications in surgery patients included pneumonia (16%), anastomotic leakage (7%), and recurrent laryngeal nerve palsy (6%). During CRT, 18% of patients developed grade 3 or higher non-hematological toxicities. The 5-year overall survival (OS) rate was 31.7%. Pathological responders had significantly longer OS than non-responders (hazard ratio 0.493, p=0.012). The distribution of distant metastasis, regimen type, clinical response, and conversion therapy modality did not have a significant impact on OS. Conversion therapy can be safely performed for ESCC with distant metastasis and has a favorable prognosis.

Unilateral Recurrent Laryngeal Nerve Palsy with H1N1 Pneumonia – An Uncommon Presentation

Abstract H1N1 pneumonia-associated vocal cord palsy is a rare condition. This case report highlights about a 70-year-old male, with multiple comorbidities, who presented with cough and shortness of breath. During hospitalization, he developed hoarseness of voice. On laryngoscopy, the right vocal cord was paralyzed. He was diagnosed with H1N1-associated right recurrent laryngeal nerve (RLN) paralysis. He received steroid therapy for the same and responded well. His voice completely recovered after 2 months. Viral infections are less common but important causes of recurrent nerve palsy. Other than influenza, severe acute respiratory syndrome coronavirus 2, Epstein–Barr Virus, cytomegalovirus, and varicella-zoster virus can also affect RLN. A detailed history, general examination, and appropriate investigations are important to exclude other possible etiological factors. Unilateral RLN palsy associated with viral infections is usually reversible and responds well to steroids as well as speech therapy.

Usefulness of an Artificial Intelligence Model in Recognizing Recurrent Laryngeal Nerves During Robot-Assisted Minimally Invasive Esophagectomy.

Recurrent laryngeal nerve (RLN) palsy is a common complication in esophagectomy and its main risk factor is reportedly intraoperative procedure associated with surgeons' experience. We aimed to improve surgeons' recognition of the RLN during robot-assisted minimally invasive esophagectomy (RAMIE) by developing an artificial intelligence (AI) model. We used 120 RAMIE videos from four institutions to develop an AI model and eight other surgical videos from another institution for AI model evaluation. AI performance was measured using the Intersection over Union (IoU). Furthermore, to verify the AI's clinical validity, we conducted the two experiments on the early identification of RLN and recognition of its location by eight trainee surgeons with or without AI. The IoUs for AI recognition of the right and left RLNs were 0.40 ± 0.26 and 0.34 ± 0.27, respectively. The recognition of the right RLN presence in the beginning of right RLN lymph node dissection (LND) by surgeons with AI (81.3%) was significantly more accurate (p = 0.004) than that by surgeons without AI (46.9%). The IoU of right RLN during right RLN LND recognized by surgeons with AI (0.59 ± 0.18) was significantly higher (p = 0.010) than that by surgeons without AI (0.40 ± 0.29). Surgeons' recognition of anatomical structures in RAMIE was improved by our AI system with high accuracy. Especially in right RLN LND, surgeons could recognize the RLN more quickly and accurately by using the AI model.

ThP2.8 - Reducing postoperative length of stay after thyroidectomy through a standardised multidisciplinary postoperative care protocol does not compromise patient safety

Abstract Aims Our unit had a significantly longer length of stay after thyroid surgery. We introduced change of practice through a standardised multidisciplinary postoperative care protocol. We analyse the effect of the protocol on postoperative length of stay and any impacts on patient safety. Methods A multidisciplinary protocol was implemented and embedded into clinical practice. Data was collected prospectively on consecutive patients undergoing thyroid surgery. Outcomes with reference to adverse events, length of stay and readmissions were audited. Comparisons were made with unit's pre-protocol data and national figures published in BAETS (British Association of Endocrine and thyroid Surgeons) audit report. Results A total of 78 patients underwent 37 total thyroidectomies and 41 lobectomies. Three (8.3%) of the total thyroidectomies had transient hypocalcaemia but none were permanent. None had voice changes or recurrent laryngeal nerve palsy. Three patients were reviewed few days after discharge with mild hypocalcaemia symptoms treated with calcium supplements. One was re-admitted 5 days post discharge with wound infection. Twenty-seven (75%) were discharged on 1st postoperative day as opposed to 0% pre-protocol (BAETS audit report 66%). Thirty-seven (90%) of lobectomies were discharged on 1st postoperative day (Units pre-protocol 42%, BAETS audit 81%). There was no postoperative bleed or hypocalcaemia. One patient with a large recurrent retrosternal goitre had transient recurrent laryngeal nerve palsy that recovered subsequently. There were no readmissions or adverse events directly related to early discharge. Conclusion A well embedded dedicated postoperative care protocol can significantly reduce postoperative hospital stay after thyroid surgery without compromising patient safety.

350. CONTINUOUS INTRAOPERATIVE NERVE MONITORING TO REDUCE THE LEFT RECURRENT LARYNGEAL NERVE PARALYSIS IN TRANSMEDIASTINAL ESOPHAGECTOMY

Abstract Introduction Transmediastinal esophagectomy (TME) is a curative option for esophageal cancer, and can achieve total mediastinal lymph node dissection (LND) with transcervical and transhiatal procedures. With the transcervical procedure, the upper mediastinal LND is highly associated with the risk of causing recurrent laryngeal nerve paralysis (RLNP). Continuous intraoperative nerve monitoring (CIONM) can visualize the risk procedure in real time, which may result in reducing postoperative RLNP. The aim of this study was to clarify the usefulness of CIONM in reducing postoperative left RLNP with TME. Material and methods A total of 227 patients who underwent TME for esophageal cancer (EC) or esophagogastric junction cancer (EGJC) between October 2017 and July 2022 at our institution were included in this study. Patients who did not undergo the upper and middle mediastinal LND (33 patients) and could not undergo CIONM (34 patients) were excluded from these 227 patients. Finally, we analyzed data on 160 patients. The clinicopathological data were reviewed from the medical record database of our institution. Results The technical implementation rate of CIONM was 87.4%. The diagnostic performance for RLNP with amplitude&amp;lt;100μV (LOS: loss of signal) at the end of transcervical procedure was as follows (sensitivity: 83.3%, specificity: 90.7%, positive diagnostic value: 88.8%). In the univariate analysis, the frequency of left RLNP was significantly higher in male, patients with primary tumor located at the upper thoracic esophagus, and patients with LOS (p&amp;lt;0.001, respectively). Moreover, the multivariate analysis identified patients with tumor located at the upper thoracic esophagus and patients with LOS (p&amp;lt;0.001) as independent risk factors for left RLNP. Conclusion In the present study, we showed the significant association between amplitude LOS and left RLNP. CIONM could contribute to reducing left RLNP by not only paying attention to amplitude reduction during surgery, but also learning the risk procedure that may cause nerve damage after surgery.

222. LONG-TERM SURVIVAL OF ROBOT-ASSISTED ESOPHAGECTOMY AND ITS UTILITY IN TREATING CT4B ESOPHAGEAL CANCER

Abstract (Background) Robot-assisted esophagectomy (RAMIE) has lately been introduced to many hospitals after its insurance approval. However, long-term outcome of RAMIE or its utility in treating cT3br-T4 esophageal cancer remains unclear. (Methods) A total of 188 esophageal cancer patients who underwent RAMIE between 2017 and 2022 were eligible in the present study. Among them, 20 cases with cT3br-T4 were reviewed to evaluate short-term outcome. Also, a comparison between RAMIE (n=66) and VATS (n=277) group with 2-year and longer follow-up time was made to evaluate their long-term outcomes. (Results) Background factors; age=71 (42-86), gender (M/F)= 145/43, tumor location (Ut/Mt/Lt, Ae)= 25/84/79, cT1/2/3/4= 36/31/101/20, cN0/1/2/3= 65/82/34/7, cM0/1= 155/33, and preoperative treatment (none/chemo/CRT/both)= 39/139/10. Surgical outcomes; operation time = 508 (273-833) min, console time=244 (108-479) min, estimated blood loss= 130 (0-2090) ml, overall postoperative morbidity (CD classification≧grade2) = 53.2% (pneumonia= 29.3%, atelectasis=9.0%, palsy of recurrent laryngeal nerve=10.1%, surgical site infection=5.9%, chylothorax=5.9%, and anastomotic leakage=5.9%). Postoperative hospital stay was 21 (12-385) days. The palsy rate of recurrent laryngeal nerve decreased from 9.1 to 0.7% after introducing intraoperative continuous nerve monitoring (NIM). In terms of RAMIE for cT3br-T4 cases (n=20), no convert to open or intraoperative complications were observed while all cases achieved R0 resection. Regarding survival comparison between the RAMIE (n=66) and the VATS (n=277) group, disease-free and overall survival were 74.8 vs 70.9% (P=0.4582), 76.4 vs 78.5% (p=0.7626), respectively. (Conclusion) NIM system reduced the palsy of recurrent laryngeal nerve during RAMIE while the comparable survival was identified between the two groups. Given its advantage, RAMIE seems to be particularly useful in treating cT3br-T4 cases. Our surgical videos of cT3br-T4 cases will be also presented in the meeting.

538. COMPARISON OF EARLY POSTOPERATIVE OUTCOMES OF CERVICAL ANASTOMOSIS TO HIGH INTRATHORACIC ANASTOMOSIS AMONG PATIENTS WITH UPPER THORACIC ESOPHAGEAL CANCER

Abstract Background For upper thoracic esophageal cancer, esophagectomy combined with cervical esophagogastrostomy (cervical anastomosis, CA) and three-field lymph node dissection (3FLND) has been proposed as the standard surgical approach. However, while CA provides sufficient length of proximal resection margins, it is associated with a higher incidence of postoperative complications such as anastomotic leaks, recurrent laryngeal nerve (RLN) injury, and increased mortality. As an alternative, high-intrathoracic esophagogastric anastomosis (high-ITA) with 3FLND has been performed. We aimed to evaluate the benefits and limitations of high-ITA compared to conventional CA in terms of early postoperative outcomes. Methods A total of 232 patients, who underwent curative esophagogastrostomy with 3FLND and either of high-intrathoracic anastomosis (high-ITA) or cervical anastomosis (CA) for upper thoracic esophageal cancer a tertiary hospital from January 2010 to December 2021. Collected data from medical records were analyzed retrospectively regarding morbidity and mortality rates. The primary end point was recurrence. Anastomotic leak, RLN palsy, hospital stay, and 90-day mortality and in-hospital mortality were evaluated using Chi-squared test, Fisher’s exact test, and T-test. The risk of mortality and recurrence were analyzed using Cox-proportional hazard regression with a median follow-up of 39.1(IQR 17.8, 80.2) months. Results Among the fifty patients with high-ITA and 182 patients with CA, the high-ITA group reported fewer anastomotic leaks (6.0% vs. 19.8%, p=0.02) and a shorter hospital stay (median 12days vs. 15 days, p&amp;lt;0.001). No significant difference was observed in RLN palsy (6.0% vs. 13.7%, p=0.22) and the 90-day or in-hospital mortality rate (2.0% vs. 2.2%, p=1.0). The number of lymph nodes dissected (LND) was similar between the groups (47.4(±15.4) vs. 52.7(±18.3), p=0.06), and there was no difference in the risk of mortality and recurrence according to the high-ITA method (HR 0.9, 95% CI 0.6-1.6; HR 1.0, 95% CI 0.6-1.7) after adjustment for age, sex, and stage. Conclusion In the esophagogastrostomy with three-field lymph node dissection, performing high-intrathoracic anastomosis may reduce the incidence of anastomotic leaks and shorten the hospital stay without adversely affecting overall survival.

347. THE EFFICACY OF CONVERSION SURGERY IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA WITH INVASION OF OTHER ORGANS

Abstract Background There are cases of advanced unresectable esophageal squamous cell carcinoma (ESCC) with invasion of other organs that can be successfully treated with chemoradiotherapy and systemic chemotherapy, enabling surgical resection. We actively perform conversion surgery for ESCC with invasion of other organs after definitive chemoradiotherapy or systemic chemotherapy. Methods The patients who underwent conversion therapy in our hospital for ESCC between 2012 and 2022 at participating institutions were retrospectively reviewed. We evaluated patient backgrounds, treatment outcomes, and overall survival (OS) were evaluated. 31 patients were enrolled. 14 conversion cases were performed after chemoradiotherapy, 17 cases were after chemotherapy. All 17 patients received systemic chemotherapy with DCF (Docetaxel + Cisplatin + 5-FU), and all 14 definitive chemoradiotherapy was administered at least 50 Gy. Results There were 24 males and 7 females with a median age of 67 (47-75) years. Involved organs were trachea in 24 cases, aorta in 6 cases, and pulmonary vein in 1 case. 19 patients underwent open esophagectomy, 11 thoracoscopic, and 1 robot-assisted. 14 patients had complications of Clavien-Dindo grade 3, mainly pneumonia, leakage, and recurrent laryngeal nerve palsy. 22 (71%) were performed R0 resection. Recurrence was observed in 20 patients (65%). Overall, 3-year PFS was 22% and 3-year OS was 39%. 3-year OS in patients with R0 resection was 49% while 12.5% in patients with R1 and 2 resection. Conclusion This study showed that conversion therapy could be relatively safely for ESCC patients with organ invasion responded to initial chemotherapy and chemoradiotherapy. Especially in cases R0 resection was performed, good prognosis was obtained.