Role of intraoperative neuromonitoring of recurrent laryngeal nerve in thyroid and parathyroid surgery

Objective To investigate whether intraoperative neuromonitoring (IONM) has a significant advantage in reducing the incidence of recurrent laryngeal nerve (RLN) injury. Methods Patients who underwent thyroid and parathyroid surgery from October 2012 to December 2017 at the Center for Thyroid and Breast Surgery of Xuanwu Hospital were retrospectively analyzed. They were divided into the IONM group and visualization alone group (VA group) according to whether IONM was used. Results In total, 1696 nerves at risk of injury (IONM group, n = 1104; VA group, n = 592) were included in the analysis. Among the high-risk nerves, permanent damage occurred in no cases in the IONM group but in one case in the VA group. Because the higher proportion of central lymph node metastasis caused difficulties in central cervical lymph node dissection and identification of the RLN, the patients undergoing lateral cervical lymph node dissection in the VA group had a significantly higher risk of postoperative RLN injury (11.76% vs. 0.00%). Conclusion IONM technology has advantages in protection of the RLN, especially in high-risk nerves and patients with a high proportion of central lymph node metastasis who require central and lateral cervical lymph node dissection.

Ultrasound diagnosis of cervical lymph node metastases in patients with first diagnosed papillary thyroid cancer and in patients previously treated surgically and admitted for radioactive iodine therapy

Purpose of the study. To evaluate the potentialities of ultrasound method in diagnosing cervical lymph node metastasis in patients with first diagnosed papillary thyroid cancer (group 1) and in patients previously treated surgically at different clinics of the Russian Federation and subsequently admitted to the A.F.Tsyb Medical Radiological Research Center — Branch of the National Medical Research Radiological Center to receive radioactive iodine therapy (group 2).Patients and methods. Patients with PTC were divided into two groups. Group 1 included 649 patients with first diagnosed PTC. All the patients underwent thyroidectomy and level VI lymph node neck dissection at the clinic of the A.F.Tsyb Medical Radiological Research Center — Branch of the National Medical Research Radiological Center. Of these patients, 92 patients underwent cervical lymph node dissection including levelsII–III–IV and 9 patients underwent cervical lymph node dissection including level VB. Group 2 consisted of 2875 patients who had previously received surgery at different clinics of the Russian Federation. Subsequently, they were admitted to our institution to receive radioactive iodine therapy. In 291 of these patients, cervical lymph node metastases were found and reoperations were performed: in 89 cases at level VI, in 170 cases at levels II–III–IV and in 32 cases at level VB. The detected metastases were verified histologically.Results. Histology confirmed the presence of nodal metastasis in 57.6% of 649 patients in group 1, and in 10.1% of 241 patients in group 2. In group 1, the incidence of metastatic disease in level VI nodes was 73% and in group 2, it was 30.6%. Metastases in levels II–III–IV were noted in 24.6% of patients in group 1, and in 58.4% of patients in group 2. Level VB metastasis was found in 2.4% of patients in group 1, and in 11% of patients in group 2. Multiple metastases were detected in 75.4% of patients in group 1, and in 20.3% of patients in group 2.Conclusion. Central lymph node metastasis was observed in 73% of patients who were first diagnosed with PTC and treated with thyroidectomy and prophylactic level VI cervical lymph node dissection. In group 2, solitary metastases to lateral lymph nodes occurred more frequently after surgical treatment for PTC, which suggested that the primary treatment was insufficiently radical.

Ameloblastic carcinoma of lower jaw (case report)

The study objectiveis to report a case of mandibular ameloblastoma.Materials and methods. A 30-year-oldfemale patient presented with swelling of the right mandibular region that appeared 8 months ago and has been slowly increasing. The patient had no other symptoms, such as pain, anesthesia, paresthesia, difficulty swallowing, mouth opening, speech disorders, fever, chills, or weight loss. Orthopantomography revealed pronounced bone resorption in the right portion of the mandibular body. Computed tomography showed a cystic cavity in this area. After incisional biopsy, the patient was diagnosed with ameloblastic carcinoma. We performed segmental mandibular resection and installed a reconstructive plate to restore mandibular integrity. We also performed selective cervical lymph node dissection (levels Ia and Ib).Results.One yearpostoperatively, the results were considered aesthetically and functionally satisfactory.Conclusion.We observed an aggressive disease phenotype with extensive localized bone destruction, typical of ameloblastic carcinoma. Extensive excision of the primary tumor and selective cervical lymph node dissection without radiotherapy ensured a relapse-free period during patient’s follow up.

PS01.142: THE IMPACT OF CERVICAL LYMPH NODE DISSECTION ON ACID AND DUODENOGASTROESOPHAGEAL REFLUX AFTER INTRATHORACIC ESOPHAGOGASTROSTOMY FOLLOWING TRANSTHORACIC ESOPHAGECTOMY

Background The aim of this study was to evaluate the impact of cervical lymph node dissection on acid and duodenogastroesophageal reflux (DGER) in patients undergoing transthoracic esophagectomy with gastric tube reconstruction and intrathoracic esophagogastrostomy. Methods Thirty one patients receiving transthoracic esophagectomy gastric tube reconstruction by intrathoracic esophagogastrostomy were subjected and divided into two groups: two field lymph node dissection group (the 2F group) and three field lymph node dissection group (the 3F group). All patients underwent 24h pH and bilirubin monitoring and gastrointestinal endoscopy one year after surgery. The results of 24h pH and bilirubin monitoring, endoscopic findings, and reflux symptoms, were compared between two groups. Results No acid reflux was observed in the 2F group, whereas it was observed in 6 (40%) of the 3F group (P = 0.023). DGER was observed in 2 patients (13%) of the 2F groups, whereas it was observed in 8 (53%) of the 3F group (P = 0.007). The percentage time of acid reflux in the 3F group was significant higher than that in the 2F group (median 0.8 vs 0%, P = 0.008). The percentage time of bile reflux in the 3F group was also significantly higher than that in the 2F group (median 2.600 vs 0%, P = 0.027). Four patients (25%) had reflux esophagitis in the 2F group, and nine patients (60%) had reflux esophagitis in the 3F group (P = 0.048). Conclusion Cervical lymph node dissection increases acid reflux and duodenogastroesophageal reflux, and can lead to the increase of the incidence of reflux esophagitis in patient with intrathoracic esophagogastrostomy. Disclosure All authors have declared no conflicts of interest.

PS02.203: CHARACTERISTICS AND RISK FACTORS OF LYMPH NODE METASTASIS IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA PATIENTS WITH PREOPERATIVE COMPUTED TOMOGRAPHY-NEGATIVE LYMPH NODES

Background Characteristics and risk factors of lymph node metastasis (LNM) in esophageal squamous cell carcinoma (ESCC) patients with preoperative computed tomography (CT)-negative lymph nodes are not well elucidated. This study aimed to identify the characteristics and risk factors of LNM in ESCC patients with preoperative CT-negative lymph nodes. Methods We conducted a retrospective analysis of consecutive ESCC patients who had preoperative CT-negative lymph nodes and received esophagectomies between August 2013 and July 2016. Lymph node with a short-axis diameter ≦10 mm on preoperative CT image was considered as CT-negative lymph node. Eligible patients included those: aged 18∼80, without neoadjuvant therapy, without other malignant tumor history, without distant metastasis, without multiple esophageal lesions, tumor locating in the thoracic esophagus, receiving McKeown esophagectomy, undergoing R0 resection, having number of lymph nodes resection≧15, pathological staging as T1a-4aN0–3. Univariate and multivariate logistic regression analyses were used to identify risk factors of LNM. Results Among 243 ESCC patients identified, 137 had LNM (56.4%). The median number of lymph nodes dissected and LNM were 24 (range 15–79) and 2 (range 1–14), respectively. The rates of LNM of the upper, middle and lower thoracic ESCC were 50.0%, 59.3% and 55.1%, respectively. The rates of LNM with the maximal short-axis diameter of lymph node on preoperative CT of ≦5 mm, 6 mm, 7 mm, 8 mm, 9 mm and 10 mm were 57.4%, 42.9%, 47.4%, 31.8%, 73.9% and 70.8%, respectively (P = 0.034). Univariate analysis showed that age (P = 0.041), maximal short-axis diameter of lymph node on CT (P = 0.034), cervical lymph node dissection (P = 0.031), lymphovascular invasion (P < 0.001) and perineural invasion (P = 0.017) were associated with LNM. Multivariate analysis revealed that cervical lymph node dissection (P = 0.018), lymphovascular invasion (P = 0.007) and perineural invasion (P = 0.025) were independent risk factors of LNM. Conclusion Our study showed that the rates of LNM were also high in ESCC patients with preoperative CT-negative lymph nodes. Standard lymph node dissection is necessary for these patients. Cervical lymph node dissection, lymphovascular invasion and perineural invasion are independent risk factors of LNM in ESCC patients with preoperative CT-negative lymph nodes. Disclosure All authors have declared no conflicts of interest.