Ameliorating Effects Of Transcutaneous Electrical Acustimulation Combined With Adaptive Biofeedback Training On Outlet Obstruction Constipation

Background:Outlet obstructive constipation（OOC）is one of the most common types of functional constipation.Stimulant laxatives are still considered the most common treatment for OOC.However,some patients’symptoms can not be fully relieved after receiving drug treatment long term use of laxatives may cause certain adverse events.The study aims to explore the effects and potential mechanism（s）of transcutaneous electrical acustimulation（TEA）combined with adaptive biofeedback training（ABT）on OOC.Methods:A total of 67 patients met the inclusion criteria and 10 patients withdrew from this study due to time and traffic problems.Finally,57 patients with OOC completed the study and were randomly assigned to receive either Macrogol 4000 Powder（MAC,10 g bid）（group A,n=20）only,ABT+MAC+Sham-TEA（group B,n=18）and,or TEA+ABT+MAC（group C,n=19）in a six-week study.Individual patients’constipation symptoms（PAC-SYM）,and constipation-quality of life（PAC-QOL）were both assessed and scored.Serum acetylcholine（Ach）and nitric oxide（NO）were measured from drawn blood samples while;individual patients’heart rate variability（HRV）was calculated at baseline and after each corresponding therapy.Meanwhile,all participants underwent high resolution anorectal manometry at the beginning and end of each treatment to obtain anal defecating pressure（ADP）.All included patients’balloon expulsion test（BET）were performed before and after treatment to obtain their balloon expulsion time.Results:Firstly,there was no significant difference in the symptom scores of the three groups before treatment.After treatment,the PAC-SYM score of group B was lower than that of group A（7.22±1.06 vs.9.40±1.50,t=5.111,P<0.001）,and the PAC-SYM score of group C was lower than that of group B（5.00±0.88 vs.7.22±1.06,t=6.946,P<0.001）;Similarly,there was no significant difference in the scores of quality of life among the three groups before treatment.After treatment,the PAC-QOL score of group B was lower than that of group A（46.50±1.62 vs.48.55±2.89,t=2.654,P=0.012）,and the PAC-QOL score of group C was lower than that of group B（44.32±3.59 vs.46.50±1.62,t=2.362,P=0.024）;After 6 weeks treatment,anorectal manometry showed that ADP in group C was significantly lower than that in group B（54.00±2.36 vs.57.39±4.00,t=2.654,P=0.003）,while ADP in group B was significantly lower than that in group A（57.39±4.00 vs.60.65±4.28,t=2.417,P=0.021）.Secondly,after 6 weeks treatment,the LF/（LF+HF）ratio in group A was significantly higher than that in group B（0.57±0.05 vs.0.51±0.04,t=4.188,P<0.001）and group C（0.43±0.05 vs.0.52±0.03,t=6.349,P<0.001）.In contrast,the HF/（LF+HF）ratio in group A was significantly lower than that in group B（0.43±0.05 vs.0.49±0.04,t=4.188,P<0.001）and group C（0.43±0.05 vs.0.52±0.03,t=6.349,P<0.001）.Finally,after 6 weeks treatment,serum Ach content in group A was significantly lower than that in group C（58.47±7.64vs.66.29±3.26,t=4.120,P<0.001）,and the serum Ach content in group B was significantly lower than that in group C（61.24±7.23 vs.66.29±3.26,t=2.764,P=0.009）;Meanwhile,serum NO content in group A was significantly higher than that in group C（119.24±10.70vs.106.89±6.21,t=4.378,P<0.001）,Moreover,the serum NO content in group B was significantly higher than that in group C（116.20±8.01 vs.106.89±6.21,t=3.964,P<0.001）;The results of balloon expulsion test shown that there were 15 cases in group A,12cases in group B and 13 cases in group C had prolonged expulsion time before treatment.However,there were 14 patients in group A,8 patients in group B and 6 patients in group C had abnormal expulsion time after treatment.BET results in Group A（15 vs.14,χ~2=0.125,P=0.723）and B（12 vs.8,χ~2=1.800,P=0.180）were unchanged after MAC and MAC+ABT+sham-TEA treatment;however,the number of patients with prolonged balloon expulsion time significantly decreased after MAC+ABT+TEA treatment（6 vs.13,χ~2=5.158,P=0.023）.Conclusion:TEA combined with ABT effectively improve constipation symptoms as well as QOL in OOC patients.It is,however,achieved by decreasing ADP and promoting balloon expulsion,which mechanisms are mediated via the autonomic and enteric mechanisms.