Abstract: 【Abstract】Objective:To investigate the perioperative characteristics and changing trends of gastric electrical activity of thoracic (tube) stomach in patients with esophageal cancer.
Methods:The clinical data of 30 patients with esophageal cancer who were admitted to the Sichuan Cancer Hospital between March 2013 and November 2013 were prospectively analyzed. All the eligible patients underwent esophageal cancer resection by IvorLewis according to the inclusion criteria. The electrogastrograms of patients were recorded at preoperative day 1 and at postoperative day 3, 7, 11 and 30. The electrogastrograms of patients at preoperative day 1 were used as the control. The parameters of electrogastrogram were analyzed including main frequency, coefficient of dominant frequency instablility, main power, postprandial/preprandial power ratio, percentage of normal gastric slow wave,percentage of slow gastric slow wave and percentage of tachycardia gastric slow wave. Measurement data with normal distritution were presented as ±s, and measurement data with skew distritution were presented as M(Qn). The postoperative time and pre and postprandial electrogastrograms were compared by the repeated measures twoway ANOVA. The comparison between groups were evaluated with the LSD test and analysis of variance.
Results:Thirty patients were screened for eligibility with a mean age of 62 years (range, 49- 75 years), including 26 males and 4 females. The pre and postprandial main frequencies were changed from 2.83±0.13 and 3.01±0.17 before operation to 2.66±0.10 and 2.82±0.10 at postoperative day 30 with coherent changing trend. The main frequencies at postoperative each time points were significantly lower than those before operation while postprandial above indicators were higher than preprandial those, showing a significant increasing trend with the passage of postoperative time (F=285.62, P<0.05）.There was no interaction between the time and meal (F=0.22, P>0.05).The pre and postprandial coefficients of dominant frequency instablility were changed from 0.133±0.031 and 0.045±0.019 before operation to 0.150±0.043 and 0.115±0.010 at postoperative day 30 with coherent changing trend, and coefficients of dominant frequency instablility at postoperative each time points were significantly higher than those before operation while postprandial above indicators were lower than preprandial those, showing a significant reducing trend with the passage of postoperative time (F=16.51, P<0.05). The pre and postprandial main powers were changed from (85±15)μV and (149±23)μV before operation to (74±9)μV and (98±10)μV at postoperative day 30, and main powers at postoperative each time points were significantly lower than those before operation, showing a significant increasing trend with the passage of postoperative time (F=48.45, P<0.05). There was interaction between the time and meal (F=7.39, P<0.05). The postprandial/preprandial power ratio was changed from 3.00±0.35 before operation to 2.52±0.25 at postoperative day 30, and postprandial/preprandial power ratios at postoperative each time points were significantly lower than those before operation, showing a significant increasing trend with the passage of postoperative time (F=26.66, P<0.05). The pre and postprandial percentages of normal gastric slow wave were changed from 81%±6% and 94%±5% before operation to 57%±5% and 70%±5% at postoperative day 30 with coherent changing trend, and percentages of normal gastric slow wave at postoperative each time points were significantly lower than those before operation while postprandial above indicators was lower than preprandial those, showing a significant increasing trend with the passage of postoperative time (F=49.36, P<0.05). There was no interaction between the time and meal (F=0.24, P>0.05). The pre and postprandial percentages of slow gastric slow wave were changed from 17%±7% and 4%±4% before operation to 32%±4% and 21%±4% at postoperative day 30 with coherent changing trend, and percentages of slow gastric slow wave at postoperative each time points were significantly higher than those before operation while preprandial above indicators were higher than postprandial those, showing a significant reducing trend with the passage of postoperative time (F=46.54, P<0.05). There was interaction between the time and meal (F=18.12, P< 0.05). The pre and postprandial tachycardia gastric slow wave percentages were changed from 1.55%(1.04%, 2.21%) and 1.95%(1.74%, 4.22%) before operation to 8.97%(5.76%, 12.02%) and 12.41%(8.04%, 16.85%) at postoperative day 30 without completely coherent changing trend, and percentages of tachycardia gastric slow wave at postoperative each time points were significantly higher than those before operation while postprandial above indicators were higher than preprandial those, showing a significant difference between before operation and postoperative day 3 (Z=11.47,13.28, P<0.05) and no significant difference among the postoperative day 7, 11, 30 (Z=1.88, 0.31, 0.03,P>0.05). There was no interaction between the time and meal (F=0.85, P<0.05).
Conclusions:After the esophagectomy, gastric electrical activity of thoracic (tube) stomach is also retained before and after the meal. There are significant differences among the main frequency, main power, coefficients of dominant frequency instablility, postprandial/preprandial power ratio, percentage of normal gastric slow wave,  percentage of slow gastric slow wave, percentage of tachycardia gastric slow wave of thoracis (tube) stomach, they have changed dynamically in the perioperative period.