Explore The Value Of Upper Gastrointestinal Contrast-enhanced X-ray Radiography In Esophageal Cancer Surgery Based On Surgical Risk And Prognostic Factors

Objective:Lymphadenectomy and reconstruction of the digestive tract are the most complicated and risky parts of esophageal cancer surgery.Lymphadenectomy is complicated which may involve the lymph nodes in the thorax,abdomen,and even the neck.Anastomotic leakage(AL)is one of the most common causes of death after esophageal cancer surgery.The upper gastrointestinal contrast-enhanced X-ray radiography(UGCXR)is an important and also special examination in the diagnosis and treatment of esophageal cancer.It could display the esophagus,stomach,and tumor in one image.So that the surgeon could obtain the anatomical location of the tumor,range of the disease,and the condition of the esophagus and stomach which would be used to reconstruct the digestive tract.They are quite important in making an esophageal cancer surgery plan.What’s more,the UGCXR is a cheap and widely used examination.However,with the widespread use of computed tomography and digestive endoscopy,the value of UGCXR is gradually being overlooked.Base on the advantages of the UGCXR,we designed this study to excavate the value of this examination in the surgical treatment of esophageal cancer.Three indexes(relative gastric length,diameter of the esophagus,location of lower tumor margin)were designed and obtained from the UGCXR to evaluate the risk of anastomotic leakage and abdominal lymph node metastasis preoperatively.So that the choice of anastomosis site(cervical or intrathoracic anastomosis)and anastomosis method(circular stapler or layered hand-sewn)could be made more scientifically,and the strategy of abdominal lymphadenectomy could be more targeted.Therefore,the rate of postoperative complications could be decreased and the prognosis of esophageal cancer patients could be improved.Materials and Methods:A retrospective review of patients who underwent esophagectomy for esophageal squamous cell carcinoma in West China Hospital from 2014 to 2017 was performed.The preoperative upper gastrointestinal contrast-enhanced X-ray radiography of all the included patients was collected from the electronic medical system.The resected surgical specimens of selected patients were retrieved from the pathology department.In the first part,the length of the greater curvature and lesser curvature of the stomach were measured on the upper gastrointestinal barium X-ray radiography(UGCXR).The distance between the esophagogastric junction(EGJ)and the top of the thoracic cavity was also collected standing for the length of the thorax.The relative gastric length(RGL)was calculated with the length of the stomach and thorax(RGL-G=(Length of the greater curvature)÷(Length of the thorax),RGL-L=(Length of the lesser curvature)÷(Length of the thorax)).The tendency of cervical anastomotic leakage rate as the changing of RGL was used to evaluate the association between them preliminarily and helped us find out the turning point of the RGL after which the incidence of leakage dominantly elevated.Then,the multivariate regression analysis would be performed to check if the turning point was the risk factor of cervical anastomotic leakage.The impact of the RGL on intrathoracic anastomotic leakage was analyzed as well.Then a propensity score match(PSM)would be performed between cervical and intrathoracic anastomosis to see if it was better to perform intrathoracic anastomosis in patients with a small RGL.The incidence of anastomotic leakage would also be compared between cervical and intrathoracic anastomosis in patients with an RGL above the cutoff value.So that the safety of cervical and intrathoracic anastomosis in patients with a larger RGL could be evaluated as well.In the second part,we compared the safety of intrathoracic circular-stapler anastomosis(CSA)and layered hand-sewn anastomosis(LHSA)in patients with a dilated esophagus.The diameter of the esophagus was measured at the level of 5centimeters above the upper tumor margin on the UGCXR.The receiver operating characteristic curve(ROC curve)was used to determine the cutoff value of the diameter.Then,a multivariate logistic regression analysis would be performed to figure out if the dilation of the esophagus is a risk factor for intrathoracic circular-stapler anastomosis.A propensity score match analysis would also be performed to see if the LHSA had a better performance on the control of anastomotic leakage than the CSA in patients with a dilated esophagus.Furthermore,the Masson’s trichrome staining was performed to figure out if the content of collagenous fiber declined with the dilation of the esophagus.In the last part of this study,we collected the resected and metastatic numbers of the lymph nodes in each lymph node station.The patients were grouped according to the site of lymph node metastasis,and the overall survival was compared among the groups.We used the distance between the lower tumor margin and the esophagogastric junction(LED)on the UGCXR to locate the lower tumor margin.The multivariate logistic regression analysis and propensity score match analysis were performed to explore the relationship between the LED and the risk of abdominal lymph node metastasis.According to the analyses,the risk of abdominal lymph node metastasis in esophageal cancer was layered based on the location of the lower tumor margin.A model predicting the risk of abdominal lymph node metastasis was constructed and presented using the nomogram.Results:In the first section,the rate of cervical anastomotic leakage dominantly increased with the decline of relative gastric length calculating from the greater curvature(RGL-G).In the comparison between the cervical anastomotic leakage group and no cervical anastomotic leakage group,the ratio of the patients with an RGL-G less than 1.3 was significantly higher in the anastomotic leakage group.The multivariate analysis also proved a small RGL was the risk factor of cervical anastomotic leakage.On the other hand,the RGL-G did not show a dominant relationship with intrathoracic anastomotic leakage.In the subgroup analysis in patients with an RGL-G less than 1.3,the incidence of anastomotic leakage was significantly higher in cervical anastomosis when comparing with intrathoracic anastomosis.And the difference remained significant after the propensity score match.However,the risk of anastomotic leakage was comparable between cervical and intrathoracic anastomosis in patients with an RGL-G greater than 1.3.In the second section,the difference in the mean value of esophageal mucous phase diameter between the patients who suffered from anastomotic leakage after intrathoracic circular-stapler anastomosis and those not was significant.The ROC curve indicated 1.79 centimeters as the cutoff value to distinguish a dilated esophagus.The logistic regression analysis indicated mucous phase diameter greater than 1.79 centimeter was a risk factor of anastomotic leakage after intrathoracic circular-stapler anastomosis(CSA).In the subgroup analysis of patients with a dilated esophagus,the rate of layered hand-sewn anastomotic leakage was significantly lower than the patients who underwent CSA,and the result remained the same in the propensity score matching cohort.As for the patients with an esophageal diameter less than 1.79 centimeters,the difference in anastomotic leakage between CSA and layered hand-sewn anastomosis did not reach statistically significant both in the original cohort and propensity score matching cohort.The Masson’s staining indicated a dominant decline of collagenous fiber content in patients with a dilated esophagus.In the last section,the survival analysis showed the overall survival of patients with abdominal lymph node metastasis(LNM)was equal to the patients with thoracic LNM,and they were superior to the patients with LNM in both the abdominal and thoracic region.The conclusion remains the same in the subgroup analysis of N1 stage patients.Therefore,the abdominal LNM had an equal impact on overall survival as thoracic LNM.The overall rate of abdominal lymph node metastasis(Ab-LNM)was 30.5% in the included patients.In the multivariate logistic regression analysis,the distance between the lower tumor margin and EGJ(LED)were identified as the risk factors of Abdominal LNM.The subgroup analysis of middle thoracic esophageal cancer showed patients with a LED less than 10 cm had a significantly higher rate of Abdominal LNM than those with a LED greater than10 cm.The subgroup analysis in lower thoracic esophageal cancer patients indicated the incidence of Abdominal LNM increased significantly when the lower tumor margin invaded the esophagogastric junction.The rate of Abdominal LNM in middle thoracic ESCC patients with a LED less than 10 cm was 32.2%,while it was 35.1%in lower thoracic cancer patients whose lower tumor margin didn’t invade the EGJ.The rate of Abdominal LNM was comparable between them even in the propensity score matching cohort.According to the above findings,we classified the risk of abdominal LNM as follow: lower esophageal cancer with a lower tumor margin invading the EGJ(high risk)> lower esophageal cancer didn’t invade the EGJ(moderate risk)= middle thoracic esophageal cancer with a distance between lower tumor margin and EGJ less than 10cm(moderate risk)> middle thoracic esophageal cancer with a distance between lower tumor margin and EGJ greater than 10cm(low risk)> upper thoracic cancer(extremely low risk)。 The predicting model of Abdominal LNM showed the probability of Abdominal LNM was over 90% when the total score in the nomogram was over 250,and it was less than 10% when the total score was less than 190.Conclusion:The upper gastrointestinal contrast-enhanced X-ray radiography(UGCXR)could play an important role in the surgical treatment of esophageal cancer.The relative gastric length(RGL)calculated from the examination is a simple but useful index to evaluate the safety of cervical anastomosis.The RGL-G of less than 1.3 is a risk factor of anastomotic leakage for cervical anastomosis,but a small RGL-G would not be a problem for intrathoracic anastomosis.So the intrathoracic anastomosis is a better choice for patients with an RGL-G of less than 1.3.If a cervical anastomosis is unavoidable,the small RGL-G could be an indicator of performing additional procedures to improve the perfusion to the gastric conduit.The content of collagenous fiber decline dominantly with the dilation of the esophagus.For patients who undergo intrathoracic anastomosis,the diameter of the esophagus obtained from the UGCXR could be the indicator of if a time-consuming layered hand-sewn anastomosis should be performed.In patients with a dominantly dilated esophagus,hand-sewn anastomosis is safer.Both the layered hand-sewn and circular-stapler anastomosis are optimal when the diameter is beneath 1.79 centimeters.So the circular-stapler anastomosis could be a better choice for a much shorter operative time under this condition.The abdominal lymph node metastasis has a great impact on the long-term survival of esophageal cancer patients.The distance between the lower tumor margin and the esophagogastric junction measured on the UGCXR could help the surgeon evaluate the risk of abdominal LNM preoperatively.According to the level of risk,the dissection of the abdominal lymph node could be more targeted.