Application Of Preoperative Ultrasonographic Evaluation Of Cervical Lymph Nodes In Selective Three-field Dissection Of Esophageal Carcinoma

Objective: Cervical lymph node metastasis has a high incidence in esophageal squamous cell carcinoma(ESCC).Cervical metastasis may occur in all segments and stages of esophageal cancer,and early cervical lymph node metastasis is easy to be ignored.For this kind of patients,partial esophagectomy and cervicothoracic three-field lymph node dissection are needed for radical cure,but the surgical trauma and postoperative complications are significantly more than those of conventional operation.Therefore,it is very important to accurately evaluate the status of cervical lymph nodes before operation and then choose three-field lymph node dissection.Color Doppler ultrasound can observe the shape,size,location,internal structure and blood flow distribution of cervical lymph nodes,and has the advantages of non-invasive and low price.The purpose of this study was to evaluate the value of color Doppler ultrasonography in preoperative evaluation of cervical lymph node metastasis of esophageal squamous cell carcinoma.Methods: The clinical data of patients with esophageal squamous cell carcinoma with suspected cervical lymph nodes detected by color Doppler ultrasound before operation in the southern district of Anhui Provincial Hospital from January 2018 to September2019 were analyzed retrospectively.60 patients were included in the group according to the inclusion and exclusion criteria.The patients whose lymph nodes were finally confirmed by color ultrasound were included in the positive group(n=28).The patients with benign lymph nodes found by color ultrasound and no metastasis of other dissected cervical lymph nodes were included in the negative group(n=32).All patients underwent thoracic laparoscopy combined with radical resection of esophageal cancer and three-field lymph node dissection.Univariate analysis was used for comparison between groups.In univariate analysis,p < 0.05 and significant variables reported in the literature were included in multivariate Logistic regression analysis.Results: There were 44 males and 16 females,with an average age of 65.68±7.42 years,ranging from 51 to 82 years old.The proportion of each segment of esophageal cancer in the two groups was 28.6%(8/28)vs 12.5%(4/32)in the upper thoracic,64.3%(18/28)vs 62.5%(20/32)in the middle thoracic,and 7.1%(2/28)vs 25.0%(8/32)in the lower thoracic,respectively.The difference was statistically significant(p<0.05).The pathological positive rate of right recurrent laryngeal lymph node in the two groups was67.9%(19/28)vs 12.5%(4/32),and the difference was statistically significant(p<0.05).The cutoff values of lymph node long diameter,lymph node short diameter and LAR were 11.5mm,6.5mm and 0.7,respectively.The area under the ROC curve of the short diameter of lymph nodes was 0.866.Multivariate analysis showed that pathology of right recurrent laryngeal lymph nodes(OR=5.960,95%CI:1.084～32.778,p=0.040)and short diameter of lymph nodes(OR=7.715,95%CI:1.359～43.818,p=0.021)were independent factors.Conclusion: Our results show that thoracic esophageal squamous cell carcinoma often metastases to cervical lymph nodes,which can occur not only in all stages of esophageal cancer,but also in all segments.The pathology of the right recurrent laryngeal nerve lymph node was highly correlated with cervical lymph node metastasis,and it was confirmed to be an independent predictor by multivariate analysis.Ultrasonography can accurately evaluate the status of cervical lymph nodes and plays an important role in preclinical staging and surgical selection of esophageal cancer.Among the ultrasonic parameters,the short diameter of lymph nodes larger than 6.5mm is the best diagnostic index.In addition,long diameter larger than 11.5mm and LAR greater than 0.7 are also of high value in the diagnosis of metastatic lymph nodes.Therefore,preoperative cervical lymph node ultrasound has a good evaluation efficiency in selective three-field lymph node dissection of esophageal cancer,and can be used as a routine examination for preoperative evaluation of three-field dissection of esophageal cancer.Especially for the patients with large short diameter and quasi-round lymph nodes found by color Doppler ultrasound before operation,three-field dissection should be performed.