Application of root seeking method and suspension method in lymph nodes dissection of recurrent laryngeal nerve during minimally invasive McKeown surgery of thoracic esophageal cancer

Abstract

Objective To investigate the application value of root seeking method and suspension method in lymph nodes dissection of recurrent laryngeal nerve (RLN) during minimally invasive McKeown surgery of thoracic esophageal cancer. Methods The retrospective cohort study was conducted. The clinical data of 120 patients with thoracic esophageal cancer who were admitted to the First Affiliated Hospital of Zhengzhou University from March 2015 to May 2016 were collected. Sixty patients using root seeking method and suspension method in lymph nodes dissection of RLN were allocated into the study group, and 60 using unexposed lymph nodes dissection of RLN were allocated into the control group. All the patients underwent minimally invasive McKeown surgeries. Observation indicators: (1) intraoperative situations; (2) postoperative situations; (3) follow-up. Follow-up using outpatient examination and telephone interview was performed to detect the postoperative tumor recurrence or metastasis and injury of RLN up to January 2017. Measurement data with normal distribution were represented as ±s. Comparisons between groups were evaluated with the independent-sample t test. Count data were analyzed using the chi-square test. Results (1) Intraoperative situations: patients between groups underwent successful minimally invasive McKeown surgery, without conversion to open surgery. The operation time and volume of intraoperative blood loss were respectively (250±19)minutes, (484±80)mL in the study group and (248±22)minutes, (493±60)mL in the control group, with no statistically significant difference between groups (t=0.532, -0.697, P>0.05). The number of lymph nodes dissection, successful dissection rate and metastasis rate in the left RLN and metastasis rate in the right RLN were respectively 5.0±4.1, 86.7%(52/60), 23.3%(14/60), 16.7%(10/60) in the study group and 1.0±0.9, 60.0%(36/60), 1.7%(1/60), 5.0%(3/60)in the control group, with statistically significant differences between groups (t=5.170, χ2=10.909, 12.876, 4.227, P 0.05). (2) Postoperative situations: time to initial anal exsufflation, time of initial defecation and time for initial fluid diet intake were respectively (2.0±0.6)days, (3.1±0.6)days, (7.2±0.3)days in the study group and (2.2±0.8)days, (3.2±0.5)days, (6.9±0.5)days in the control group, with no statistically significant difference between groups (t=2.618, -0.991, 3.985, P>0.05). Comparisons of injury degree of RLN: 5 and 1 patients in the study and control groups had mild injury, respectively, showing no statistically significant difference between groups (χ2=1.581, P>0.05); 1 and 8 patients in the study and control groups had respectively moderate injury, showing a statistically significant difference between groups (χ2=4.323, P 0.05). (3) Follow-up: 120 patients were followed up for 4-22 months, with a median time of 13 months. During the follow-up, 3 and 2 patients in the study and control groups had cervical lymph node metastases and received postoperative assisted chemotherapy and local radiotherapy of neck, without death between groups. There was no hoarseness in 6 patients with mild injury of RLN during the follow-up; voices in 9 patients with moderate injury of RLN were improved at 1-2 months postoperatively, and no bucking symptom was detected after fluid diet intake. Conclusion The root seeking method and suspension method in lymph nodes dissection of RLN is safe and effective during minimally invasive McKeown surgery of thoracic esophageal cancer, especially conducive to lymph nodes exposure and dissection of the left RLN, and reduce the incidence of moderate injury of RLN. Key words: Esophageal neoplasms; Injury of recurrent laryngeal nerve; Minimally invasive McKeown surgery; Lymph node dissection