ABSTRACT
Objective:To investigate the characteristics of three-dimensional high resolution anorectal manometry and the effect of biological feedback therapy on the improvement of clinical symptoms in very elderly patients with chronic functional constipation.Methods:A total of 68 cases with chronic functional constipation were divided into very elderly group(≥80 years old, n=36)and the elderly group(60-79 years old, n=32)in the retrospective analysis.Patients underwent the three-dimensional high resolution anorectal manometry before and after biological feedback therapy, and the related parameters and scores of constipation symptoms before and after treatment were compared between the two groups.Results:The results of 3D high-resolution anorectal manometry showed that the anus relaxation rate in the simulated defecation test was lower and the bowel threshold in the rectal sensory threshold test was higher in the very elderly group than in the elderly group(2.44±33.81% vs.16.34±16.99%, 103.44±42.01 ml vs.77.22±41.85 ml, t=-2.047 and 2.655, P=0.049 and 0.012). In the very elderly group, the post-biological feedback therapy versus pre-biological feedback therapy showed that anal residual pressure during simulated defecation was decreased, the absolute value of negative anorectal pressure difference was reduced and the anal relaxation rate was increased [57.50±18.88 mmHg(1 mmHg=0.133 kPa) vs.64.84±25.82 mmHg, -29.64±15.98 mmHg vs.-39.47±19.45 mmHg, 10.53±29.35% vs.2.44±33.81%, t=3.342, -4.902 and -3.209, P=0.002, 0.000 and 0.003]. The scores of clinical symptom scale showed that there was no significant difference in the effective rate between the very elderly and elderly groups(66.67% or 24/36 vs.71.88% or 23/32, χ2=0.760, P=0.860). Conclusions:The elderly functional constipation patients with defecation disorder often have rectal propulsive insufficiency and dyscoordination of pelvic floor muscle contraction.The main cause of defecation disorder in very elderly patients is the decrease of anal relaxation rate during simulated defecation.Biological feedback therapy can improve the symptoms of defecation disorder in very elderly patients by reducing the anal residual pressure during simulated defecation, increasing the anal relaxation rate and reducing the absolute value of negative anorectal pressure difference.