Clinical Outcomes Of Endoscopic Treatment For Intestinal Laterally Spreading Tumors

Aims:(1)To compare the efficacy and safety of endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)for the treatment of non-ampullary duodenal laterally spreading tumors(NAD-LSTs)and to evaluate the risk factors for delayed perforation after endoscopic resection(ER)of NAD-LSTs;(2)to compare the efficacy and safety of ESD and endoscopic submucosal tunnel dissection(ESTD)for the treatment of rectal LSTs;(3)to compare the efficacy and safety of EMR,modified EMR,ESD and modified ESD for the treatment of colorectal LSTs.Methods:This study was divided into three parts.The first part:A total of 54 patients with 54 NAD-LSTs treated with ER at the Chinese PLA General Hospital between January 2007 and January 2018 were retrospectively analyzed.Compare the EMR group and ESD group in terms of en bloc resection,R0 resection,procedure-related adverse events and local recurrence,evaluate the risk factors for delayed perforation after ER of NAD-LSTs,and analyse the clinical outcomes of local recurrence cases.The second part:A total of 143 patients with 143 rectal LSTs treated with ESD or ESTD at the Chinese PLA General Hospital between January 2009 and June 2018 were retrospectively analyzed.Compare the ESD group and ESTD group in terms of dissection speed,en bloc resection,R0 resection,procedure-related adverse events.The third part:A total of 146 patients with 146 colorectal LSTs treated with ER at the Chinese PLA General Hospital between January 2016 and March 2018 were retrospectively analyzed.Compare the EMR group,modified EMR group,ESD group and modified ESD in terms of en bloc resection,R0 resection,procedure-related adverse events and local recurrence.Results:The first part:The mean(SD)lesion size of NAD-LSTs was 26.9 mm(8.5).EMR was performed in 21 lesions,ESD was performed in 33 lesions.En bloc resection was achieved in 97.0%of the ESD group and 52.4%of the EMR group(p=0.000).R0 resection was achieved in 93.9%of the ESD group and 38.1%of the EMR group(p=0.000).Delayed bleeding was noted in one EMR patient and one ESD patient,and there was no significant difference between the two group(p=1.000).The two delayed bleeding cases were all successfully treated by endoscopic interventions.Delayed perforation was noted in three ESD patients and one EMR patients,and there was no significant difference between the two group(p=0.953).The four delayed perforation cases were all successfully treated by endoscopic closure.The incidence of delayed perforation showed a significant association with post-ampullary tumor location(p=0.030).Compare the outcomes between recurrence group and non-recurrence group,the lesion size was significantly larger in the recurrence group than in the non-recurrence group(p=0.005).Besides,all the recurrence cases were removed by endoscopic piecemeal mucosal resection(EPMR)(p=0.001).The second part:The median specimen area was 8.83 cm2(range of 2.36-50.24 cm2).ESD was performed in 84 lesions,ESTD was performed in 59 lesions.The median specimen area was significantly larger in the ESTD group than in the ESD group(12.56 cm2 vs.6.32 cm2,p<0.001).The median dissection speed was significantly higher in the ESTD group than in the ESD group(23.92 mm2/min vs.15.16 mm2/min,p<0.001).The en bloc resection rate was higher in the ESTD group than in the ESD group,however,there was no statistical significance(98.3%vs.91.7%,p=0.183).The R0 resection rate was higher in the ESTD group than in the ESD group,however,there was no statistical significance(94.9%vs.88.1%,p=0.163).The rate of intraoperative adverse events was lower in the ESTD group than in the ESD group,however,there was no statistical significance(3.4%vs.10.7%,p=0.194).There was no significant difference between the two groups in terms of the delayed bleeding rate(ESD group:2.4%vs.ESTD group:1.7%,p=1.000).The third part:The distribution of the LSTs subtypes was as follows:granular homogeneous,25 cases;granular nodular mixed,66 cases;nongranular flat elevated,44 cases;and nongranular pseudodepressed,11 cases.EMR was performed in 23 tumors,modified EMR was performed in 29 tumors,ESD was performed in 50 tumors,and modified ESD was performed in 44 tumors.Median tumor diameter was 2.5 cm(range of 1.2-10.0 cm).The en bloc resection rate and R0 resection rate were 78.8%and 75.3%,respectively.The intraoperative perforation rate and delayed bleeding rate were 4.8%and 2.1%,respectively.The en bloc resection rate and R0 resection rate were significantly higher in ESD group than the other three groups.There was no statistical significance in terms of adverse events rate among the four groups.Follow-up endoscopy was performed in 117 cases with a median period of 10.0 months(range of 3.0-26.0 months),and local recurrence was identified in seven cases.Conclusions:The first part:(1)ER of NAD-LSTs is a feasible treatment,however,the incidence of procedure-related adverse event is relatively high;(2)Compare of EMR,ESD can acquire a higher en bloc resection rate and R0 resection rate;(3)NAD-LSTs located distal to the Vater's ampulla is associated with high incidence of delayed perforation;(4)Piecemeal EMR is associated with high local recurrence,which highlights the need for careful follow-up assessment to ensure that recurrence can be detected at an early stage.The second part:The ESTD technique can effectively improve the dissection speed and decrease the total procedure duration for the treatment of rectal LSTs.The third part:(1)ESD should be the optimal method for the resection of colorectal LSTs;(2)LSTs smaller than 20 mm can be resected by EMR;(3)Modified EMR and modified ESD have their respective advantages for the treatment of LSTs.