A Clinical Study Of Endoscopic Mucosal Resection And Endoscopic Submucosai Dissection In Treating Rectal Carcinoid Tumors

Objective: To evaluate the efficacy and safety of endoscopic submucosal dissection(ESD)for rectal carcinoid tumors by comparing with endoscopic mucosal resection(EMR).Methods: Data of patients with rectal carcinoid tumors between December 2012 to December 2017,who received EMR(n=28)or ESD(n=100)were reviewed to compare the diameter measured by EUS,operation time,average hospital stay,en bloc resection rate,complication,R0 resection rate,and recurrence rate between two methods.Inclusion criteria:(1)confirmed histological diagnosis of rectal carcinoid tumors,(2)lesions no larger than 20 mm,(3)EUS revealed the lesions should be contained within submucosal layer,(4)no symptoms of carcinoid syndrome,and(5)no pararectal lymph node and distant metastases found before the procedure.Results:There were 100 patients in the ESD group and 28 patients in the EMR group.No significant differences were observed in age,gender ratio,tumor location,and tumor morphological between the two groups.Diameter measured by EUS in ESD group(6.9±4.0mm)was significantly higher than that in EMR group(6.2±2.9mm,P>0.05).Specimen size(15.0±7.9)mm in ESD group was significantly larger than that of EMR group(9.5±3.2mm,P<0.05);Diameter of pathology in the ESD group(5.6±3.7)mm has no significant difference with EMR group(4.1±3.1mm)(P>0.05).As for lesion depth,ESD group accounted for 97% from the submucosa,2% from the mucosal layer,1% from the muscularis propria,and 21.4%,78.6%,0% in the EMR group,respectively.Mean operation time of ESD group(20.4±9.7min)was significantly longer than that of EMR group(8.2±4.8min,P<0.01);Mean average hospital stay in ESD group(6.0±2.4)day was significantly longer than that of EMR group(3.3±1.9day,P<0.01).En bloc resection and R0 resection rates were similar between EMR(100.0%,78.6%,respectively)and ESD group(100.0%,85%,respectively).Complications including perforation and delayed bleeding in EMR group was(0%,7.1%,while in ESD groups was 4%,1%,P>0.05).In the ESD group,11 cases with lesions larger than 10 mm in the largest lesion size,of which 5 cases showed positive margin;1 case in EMR group and 1 pathological positive margin after operation.No local recurrence had been detected both in the EMR group and ESD group.Conclusion: For endoscopic treatment of rectal carcinoid tumors,if the EUS revealed lesion diameter <10mm,the depth of the lesion is limited to the submucosa,no lymph nodes and distant metastasis,EMR treatment hold obvious advantages than ESD therapy in the average operating time,average length of stay and so on.When the maximum diameter of the tumor is greater than 10 mm,whether EMR or ESD,complete pathological resection rate can not achieve satisfactory results.Safer and more effective treatments are worthy of further exploration.