The Study On Anorectal Dynamics In Patients With Internal Rectal Prolapse And Pelvic Floor Dyssynergia

ObjectiveInternal rectal prolapse(IRP)and pelvic floor dyssynergia(PFD) both are the most common type of outlet obstructive constipation(OOC).The therapeutic efficacy of them are unsatisfaction because of uncompletely knowed of their pathophysiology.We designed this test to study anorectal dynamics and pathophysiology of IRP and PFD so as to make effective therapeutic plan.Methods1.Subjects and groupsWe continuously choosed 32 IRP and 32 PFD which were diagnosed by defecography from the patients visited Daping Hospital of Third Military Medical University.The IRP group included 22 rectal mucosal prolapse(RMP) and 10 full thickness rectal intussusception(FTRI).Simultaneously,we choosed 18 volunteers to act as control group. All the subjects consented to join the test.2.Research indexsWe used Medtronic Keypoint Polygraf,Medtronic Keypoint KP and defecography film to detect following indexs.1) Anal sphincter function Included resting anal pressure,voluntary contraction anal pressure and coughing anal pressure.2) Rectal sensation The volume to elicit the first rectal sensation,the volume to elicit the first awareness of defecation and the maximum volume can be tolerated.3) Rectoanal inhibitory reflex(RAIR) Whether the subjects have RAIR and the minimum volume to initiate RAIR.4) Perineum descend The perineum descend was measured by direct method and by defecography.5) Electromyography of puborectalis(PR) and anorectal angle(ARA) The mean break-over and swing of PR in rest,straining and contraction were measured by a concentric needle electrode.The ARA of IRP and PFD in rest and straining was measured on defecography film.6) Rectal evacuation The subjects was asked to evacuate a 60 ml balloon in rectum.The anal pressure and rectal pressure were measured in straining.Rectal evacuation rate was measured by analogue evacuation.Results1.Anal sphincter functionThe resting anal pressure,voluntary contraction anal pressure and coughing anal pressure in IRP group were lower than that in control group.The resting anal pressure in FTRI group were lower than that in RMP group.The resting pressure in PFD group were higher than that in control group(respectively P＜0.01).2.Rectum sensationThe volume to elicit rectal primary sensation and primary awareness of defecation in PFD group and IRP group were higher than those in control group.The maximum toleration volume in PFD group and IRP group were lower than those in control group(P＜0.01 or P＜0.05).3.RAIRAll the subjects had RAIR.There were no obviously diference between the minimum volume to elicit RAIR in IRP group and control group(P＞0.05).The minimum volume to elicit RAIR in PFD group was higher than those in control group(P＜0.01).The minimum volume to elicit RAIR in PFD group was correlated with the minimum volume to elicit rectal primary sensation(r=0.670,P＜0.01).The correlation equation was y= 4.570+0.461x.4.Perineum descendThe perineum descend measured by direct method was concord to those measured by defecography.The perineum descend in straining of IRP group was higher than that of control group and the perineum descend in straining of FTRI group was higher than that of RMP group(P＜0.01).The perineum descend in straining of PFD group was lower than that of control group(P＜0.01).5.Electromyography of PR and ARA 1) Electromyography of PR The mean break-over in straining were lower than in rest of FTRI and control group.The mean break-over in straining were higher than in rest in PFD group(P＜0.01 or P＜0.05).2) ARA The ARA of IRP group in straining was bigger than in rest.The ARA of PFD group in straining was smaller than in rest(P＜0.01).6.Rectal evacuation1) Rectal evacuation The rectal evacuation in IRP and PFD group were lower than that in control group(P＜0.01).The rectal evacuation in FTRI group was lower than that in RMP group(P＜0.01).There was no obviously difference between in RMP and control group(P＞0.05).2) Anorectal pressure in straining The rectal pressure was higher than the anal pressure in straining of IRP and control group.The rectal pressure was lower than the anal pressure in straining of PFD group(P＜0.01).Conclusions1.The support tissue of pelvic floor in IRP patients became loose,which was serious in FTRI patients than that in RMP patients.These changes included decreased anal pressure and increased perineum descend.While the support tissue of pelvic floor in PFD patients had spasm changes that increased anal pressure,abnormal RAIR,decreased perineum descend and that the rectal pressure lower than anal pressure in straining.2.There were decreased rectal sensation in IRP patients and PFD patients.3.Decreased rectal evacuation didn't exist in RMP patients,but existed in FTRI and PFD patients.In conclusion,we think that IRP had loosed change of support tissue of pelvic floor and decreased rectal sensation,and these changes of pelvic floor were serious in FTRI than in RMP.There were decreased rectal evacuation in FTRI patients,while not in RMP patients.There were spasm change of support tissue of pelvic floor,decreased rectal sensation and decreased evacuation in PFD patients.