Abstract: Objective:To investigate the shortterm clinical effects of selecting duodenal transection timing on laparoscopicassisted distal gastrectomy (LADG).
Methods:The retrospective cohort study was conducted. The clinicopathological data of 239 gastric cancer (GC) patients undergoing LADG in the 5 medical centers between March 2016 and March 2018 were collected, including 104 in the First Affiliated Hospital of Xiamen University, 45 in Zhangzhou Affiliated Hospital of Fujian Medical University, 35 in Quanzhou Affiliated Hospital of Fujian Medical University, 30 in the Second Affiliated Hospital of Xiamen Medical College, 25 in Zhongshan Hospital of Xiamen University. Of 239 patients undergoing LADG + D2 lymph node dissection, 107 receiving duodenal transection and then lymph node dissection in the upper region of pancreas after lymph node dissection in the lower region of pylorus and 132 receiving lymph node dissection in the upper region of pancreas and then duodenal transection were respectively divided into anterior approach group and posterior approach group. Sixtyfour, 8, 16, 14 and 5 patients in the anterior approach group and 40, 37, 19, 16 and 20 patients in the posterior group respectively came from the First Affiliated Hospital of Xiamen University, Zhangzhou Affiliated Hospital of Fujian Medical University, Quanzhou Affiliated Hospital of Fujian Medical University, Second Affiliated Hospital of Xiamen Medical College and Zhongshan Hospital of Xiamen University. Observation indicators: (1) surgical and postoperative situations; (2) postoperative complications; (3) stratified analyses of surgical and postoperative situations in patients with different TNM staging, body mass index (BMI) and maximum tumor dimension; (4) followup and survival. Followup using outpatient examination and telephone interview was performed to detect postoperative overall survival and tumor recurrence or metastasis up to April 2018. Measurement data with normal distribution were represented as ±s, and comparison between groups was analyzed using the independentsamples t test. Measurement data with skewed distribution were described as M (Q), and comparison between groups was analyzed using the nonparametric test. Comparisons of count data were analyzed using chisquare test or Fisher exact probability. Comparison of ordinal data was done by the ranksum test.
Results:(1) Surgical and postoperative situations: all the patients underwent successful operation, without perioperative death. Number of lymph node dissection in the upper region of pylorus in the anterior and posterior approach groups were respectively 3.9±2.6 and 3.0±2.5, with a statistically significant difference between groups (t=2.778, P<0.05). Cases with Billroth Ⅰ, Billroth Ⅱ, Billroth Ⅱ+Bruan and Roux-en-Y of digestive tract reconstruction, operation time, dissected times of lymph nodes in greater curvature of stomach, lower region of pylorus, upper region of pancreas and lesser curvature of stomach, cases with visible port vein, volume of intraoperative blood loss, number of overall lymph node dissection, numbers of lymph node dissection in greater curvature of stomach, lower region of pylorus, upper region of pancreas and lesser curvature of stomach, time to postoperative anal exsufflation, time for postoperative fluid diet intake, time for postoperative semifluid diet intake, intraperitoneal drainagetube removal time and duration of postoperative hospital stay were respectively 16, 32, 47, 12, (233.0±41.0)minutes, (14.6±5.4)minutes, (21.9±6.3)minutes, (32.7±6.8)minutes, (7.4±2.9)minutes, 74, (87±73)mL, 35.0±10.0, 8.5±4.1, 4.8±4.2, 13.3±5.2, 4.3± 3.3, (4.1±2.6)days, (5.4±2.8)days, (7.9±3.5)days, (8.9±2.9)days, (11.7±4.5)days in the anterior approach group and 17, 47, 61, 7, (243.0±44.0)minutes, (15.7±5.2)minutes, (23.1±8.0)minutes, (34.2±7.1)minutes, (7.9±2.8)minutes, 79, (93±57)mL, 33.0±10.0, 8.1±4.8, 5.3±4.9, 12.5±5.6, 3.8±2.4, (3.8±3.3)days, (5.0±3.6)days, (7.5±4.0)days, (8.5±3.8)days, (11.3±5.7)days in the posterior approach group, with no statistically significant difference between groups (x²=3.431, t=-1.836,-1.546,-1.324,-1.634,-1.228,  HT2.HT5”SS x²=2.552, t=-0.684, 1.630, 0.797,-0.871, 1.148, 1.314, 0.954, 0.951, 0.884, 1.065, 0.694, P>0.05). (2) Postoperative complications: cases with overall complications, anastomotic leakage, anastomotic stenosis, anastomotic bleeding, pancreatic fistula, postoperative gastroparesis, intraabdominal hemorrhage, incision infection, pneumonia, intraabdominal infection, bacteremia, intestinal obstruction, endolymphatic leakage, ClavienDindo grade Ⅰ,Ⅱ, Ⅲa, Ⅲb and Ⅳa of postoperative complications were respectively 15, 1, 1, 1, 0, 3, 1, 2, 3, 0,1, 3, 0, 3, 9, 1, 2, 0 in the anterior approach group and 25, 3, 0, 1, 2, 2, 2, 5, 7, 3, 2, 3, 1, 6, 14, 1, 2, 2 in the posterior approach group, with no statistically significant difference between groups (x²=1.027, 0.643, 0.022, 0.479, 0.161, 0.765, 0.921, 0.161, 0.063, Z=-1.055, P>0.05). Patients in 2 groups with complications were cured by symptomatic treatment. (3) Stratified analyses of surgical and postoperative situations in patients with different TNM staging, BMI and maximum tumor dimension: operation time, dissected times of lymph nodes in upper region of pancreas, cases with visible port vein, number of overall lymph node dissection, numbers of lymph node dissection in upper region of pylorus and upper region of pancreas were respectively (236.0±41.0)minutes, (33.9±6.2)minutes, 32, 36.0±12.0, 3.8±3.0, 13.4±5.5 in patients of the anterior approach group with Ⅲ stage of TNM staging and (253.0±45.0)minutes, (36.5± 7.0)minutes, 29, 31.0±9.0, 2.5±2.0, 11.4±4.6 in patients of the posterior approach group with Ⅲ stage of TNM staging, with statistically significant differences between groups (t=-1.988,-2.066, x²=4.686, t=2.472, 2.757, 2.016, P<0.05). Numbers of overall lymph node dissection and number of lymph node dissection in upper region of pylorus were respectively 37.0±12.0, 3.6±3.1 in patients of the anterior approach group with BMI ≥ 25 kg/m² and 30.0±7.0, 2.0±1.3 in patients of the posterior approach group with BMI ≥ 25 kg/m², with statistically significant differences between groups (t=2.211, 2.205, P<0.05). Volume of intraoperative blood loss and number of lymph node dissection in upper region of pylorus were respectively (80±45)mL, 4.0±2.6 in patients of the anterior approach group with maximum tumor dimension ≥ 3.3 cm and (110±67)mL, 2.8±1.8 in patients of the posterior approach group with maximum tumor dimension ≥ 3.3 cm, with statistically significant differences between groups (t=-2.320, 2.589, P<0.05). (4) Followup and survival: of 239 patients, 202 were followed up for 2-24 months, with a median time of 12 months, including 89 in the anterior approach group and 113 in the posterior approach group. During the followup, cases with overall survival, tumor recurrence and metastasis were respectively 85, 3, 8 in the anterior approach group and 109, 3, 11 in the posterior approach group, with no statistically significant difference between groups (x²=0.032, 0.089, 0.119, P>0.05).
Conclusions:Both of anterior approach and posterior approach are safe and feasible in LADG, with equivalent shortterm efficacies. The anterior approach in LADG has an advantage of the lymph node dissection in the upper region of pylorus compared with posterior approach, and it also is better for patients with later tumor staging, higher BMI and bigger tumor.