Study On Electrogastrogram Of Pre-and Postoperative And Gastric Emptying In Patients With Gastric Cancer

Objective: Gastric electric activity of stomach smooth muscles controls its contraction and dilatation, one of rhythmic myoelectrical signal changes of gastric electric activity could be recorded by electrogastrogram (EGG), one of the noninvasive methods, through the abdominal electrodes. Character of gastric electric activity changes in gastric cancer patients is still indefinite, and relationship between gastric electric activity changes and gastric emptying has not been reported to our knowledge. To know the character of electrogastrogram in gastric cancer patients, provide more evidence to electrogas trogram clinical application, we compared the EGG changes in preoperative and postoperative gastric cancer patients, and relationship between preoperative gastric electric activity and gastric emptying.Methods: EGG was recorded by mobile Digitrapper dipl-electrode electrogastrogram recorder (Synectics Company, Sweden), 54 gastric cancer patients including 27 preoperative gastric cancer (Pre-GC) patients (14 males and 13 females, the average age was 47.19) and 27 postoperative gastric cancer (Post-GC) patients (14 males and 13 females, the average age was 48.52) and 20 health controls (10 males and 10 females, the average age was 45.21) were involved in this study. The fasting measurement was recorded for 30 minutes and the postprandial recording for 60 minutes. The EGG parameters contained dominant frequency (DF), dominant frequency in normal range (N%), dominnant power (DP), bradygastria (B%), tachygastria (T%), dominant frequency instability coefficient (DFIC), and power ratio (PR), respectively. Four hour's gastric emptying rate was calculated by Rom's method. Gastric emptying rate≤80% was considered as delayed gastric emptying. All statistical analysis was performed by SPSS 11.5 software, P<0.05 was considered as significant.Results: 1 Compared with controls fasting DP was 39.47±12.86 of Pre-GC patients vs 29.16±4.71 of controls (P<0.001); so do postprandial DP 42.78±13.53 of Pre-GC patients vs 33.24±2.47 of controls (P<0.05). Compared with controls fasting T% was 23.17±13.84 of Pre-GC patients vs 13.12±10.67 of control- s (P<0.05); so do postprandial T% 23.71±13.67 of Pre-GC patients vs 10.91±8.01 of controls (P<0.001). Compared with controls fasting N% was 66.37±14.99 of Pre-GC patients vs 76.38±13.66 of controls (P<0.05); so do postprandial N% 67.43±13.28 of Pre-GC patients vs 77.39±12.62 of controls (P<0.05). DP and T% in Pre-GC were all significantly higher than that of controls; N% was lower than controls.Postprandial DF was increased compared with fasting, so do DP. DF and DP of Pre-GC patients upon meal induction were 2.83±0.35 vs 2.90±0.38 cpm (P<0.05); 39.47±12.86 vs 42.78±13.53 (P<0.05) respectively. But other gastric electrical activity parameters were unchanged (data not shown). Sex, age and BMI of Pre-GC patients had no influences on gastric electrical activity parameters; PR of controls had positive correlation with BMI (r=0.422, P=0.045). Age and sex of controls had no influences on gastric electrical activity parameters.All fasting and postprandial parameters of Pre-GC patients among four groups (BorrmannⅠ,Ⅱ,Ⅲ,Ⅳ) had no significant difference (P>0.05). Parameters among three groups (carcino- ma of gastric cardia, corpus gastricum and sinus ventriculi) had no significant difference (P>0.05).Compared with fasting postprandial amplitude vibration of controls increased by EGG recording, gastric electrical frequent- cy was regular in three-dimension graphics, DF was 3cpm per minute; Compared with fasting postprandial amplitude vibration of Pre-GC patients also increased by EGG recording, but electrogastrogram wave was irregular, gastric electrical frequen- tcy was irregular in three-dimension graphics.2 Fasting DF was 2.53±0.36 cpm of Post-GC patients, 2.92±0.26 cpm of controls (P<0.05); Postprandial DF was 2.68±0.34 cpm of Post-GC patients, 3.04±0.20 cpm of controls (P<0.05). Fasting N% was 62.01±13.82 of Post-GC patients, 76.38±13.66 of controls (P<0.05); Postprandial N% was 60.04±11.53 of Post-GC patients, 77.39±12.62 of controls (P<0.001). Fasting B% was 15.19±11.01 of Post-GC patients, 7.17±6.48 of controls (P<0.05); Postprandial B% was 15.82±7.30 of Post-GC patients; 7.99±5.81 of controls (P<0.001). Fasting T% was 19.48±9.99 of Post-GC patients, 13.12±10.67 of controls (P<0.05); Postprandi- al T% was 21.83±8.61 of Post-GC patients; 10.91±8.01 of controls (P<0.001). DF and N% of Post-GC patients were all lower than that of controls, B% and T% were higher than that of controls, postprandial DFIC was 0.45±0.10 of Post-GC patients, 0.32±0.11 of controls (P<0.001). DFIC of Post-GC patients were higher than controls.EGG wave of total gastrectomy patients was irregular, gastric electrical frequency was irregular in three-dimension graphics and 3cpm wave was disappeared; In subtotal gastric- tomy patients, gastric electrical activity frequency was irregular in three-dimension graphics, but 3cpm wave can be detected.Fasting DF was 3.01±0.38 cpm in proximal gastrectomy, 3.06±0.29 cpm in distal gastrectomy, 2.54±0.12 cpm in total gastrectomy (F=6.225, P=0.007); Postprandial DF was 2.88±0.36 cpm in proximal gastrectomy, 2.84±0.37 cpm in distal gastrectomy, 2.30±0.1 cpm in total gastrectomy (F=5.315, P=0.013). Fasting N% was 63.95±9.96 in proximal gastrectomy, 66.58±12.69in distal gastrectomy, 44.00±2.80 in total gastric- tomy (F=8.094, P=0.002); Postprandial N% was 61.32±4.74 in proximal gastrectomy, 63.97±13.68 in distal gastrectomy, 46.44±11.50 in total gastrectomy (F=4.113, P=0.030). DF and N% had no significant difference between proximal gastrectomy and distal gastrectomy (P>0.05); DF and N% of proximal gastric- tomy and distal gastrectomy were higher than total gastrectomy (P<0.05); PR was 1.27±0.24 in proximal gastrectomy, 1.04±0.13 in distal gastrectomy, 1.12±0.22 in total gastrectomy (F=3.580, P=0.045). PR of proximal gastrectomy was higher than that of total gastrectomy patients (P<0.05); there was no signi- ficant difference between proximal gastrictomy and distal gastri- ctomy, also distal gastrectomy and total gastrectomy patients (P>0.05).3 Fasting DF was 2.53±0.36 cpm in Post-GC patients, 2.83±0.35 cpm in Pre-GC patients (P<0.05); Postprandial DF was 2.68±0.34 cpm in Post-GC patients, 2.90±0.38 cpm in Pre-GC patients (P<0.001). Fasting DP was 31.54±6.54 in Post-GC patients, 39.47±12.86 in Pre-GC patients (P<0.05); Postprandial DP was 34.15±4.28 in Post-GC patients, 42.78±13.53 in Pre-GC (P<0.05). Fasting B% was 15.19±11.01 in Post-GC patients, 7.90±6.13 in Pre-GC patients (P<0.05); Postprandial B% was 15.82±7.30 in Post-GC patients, 7.32±3.19 in Pre-GC patients (P<0.001). Fasting N% was 62.01±13.82 in Post-GC patients, 66.37±14.99 in Pre-GC patients (P<0.05); Postprandial N% was 60.04±11.53 in Post-GC patients, 67.43±13.28 in Pre-GC (P<0.05). DF and DP of Post-GC patients were lower than Pre-GC patients, B% was higher than Pre-GC patients, and postprandial N% was lower than Pre-GC patients.4 In 20 controls, 75 percent with normal gastric emptying; in 27 Pre-GC patients, 33.3 percent with normal gastric emptying. There was significant difference between two groups (P=0.007).In 18 Pre-GC patients showed delayed gastric emptying, 83.33 percent with abnormal electrogastrogram; in patients with abnormal electrogastrogram, 73.33 percent with tachygastria, and 26.67 percent with bradygastria. In Pre-GC patients showed normal gastric emptying, 33.3 percent with abnormal electro- gastrogram, all with tachygastria. In 5 controls showed delayed gastric emptying, 60 percent with abnormal electrogastrogram, all with tachygastria. In 15 controls showed normal gastric emptying, 20 percent with abnormal electrogastrogram, all with tachygastria.In Pre-GC patients, fasting and postprandial N% were positively correlated with four hour's gastric emptying rate (r=0.406, P=0.04), (r=0.401, P=0.042), T% was negatively correlated with four hour's gastric emptying rate (r=-0.468, P=0.016), (r=-0.604, P=0.001). Whereas, in the normal controls, there were no relationship between all fasting parameters and four hour's gastric emptying rate, postprandial N% was positively correlated with four hour's gastric emptying rate (r=0.473, P=0.030), B% was negatively correlated with four hour's gastric emptying rate (r=-0.483, P=0.027).Conclusions: 1 Compare with controls, abnormal gastric myoelectrical activity of Pre-GC patients are include the decrease of N%, increase of DP and T%. Sex, age, BMI, Borrmann classification and tumor location have no obviously influences respectively on parameters of Pre-GC patients. 2 Compare with controls, abnormal gastric myoelectrical activity of Post-GC patients are include the decrease of DF and N%, increase of T% and B%. No statistical defference exists between gastric electrical activity parameters of proximal gastrectomy and that of distal gastrectomy.3 Compare with Pre-GC patients, abnormal gastric electrical activity rate of Post-GC is increased, mainly include the decrease of DF, N% and DP, increase of B%.4 Delayed gastric emptying may exist in gastric cancer patients, and delayed gastric emptying is more accompany with tachygastria. In Pre-GC patients, N% is positively correlated with four hour's gastric emptying rate; T% is negatively correlated with four hour's gastric emptying rate.