The Initial Study Of The Relationship Between Muscle Strength Of The External Anal Sphincter, Anal Canal Rest Pressure And The Recovery Of The Function Of The Spinal Cord

Objective: In clinical practice, the author found that the muscle strength of the external anal sphincter was changed from appear to weak, and than became strong as the recovery of the function of the spine in the convalescent period of the spinal cord injury. If we just described it use the word"presence", the changes in the convalescent period. Meanwhile, the author also found that if the anal canal was looseness, the low spinal cord central reflex and the independent construction of the anal sphincter will not recover; and if the reflex and the independent construction of the anal sphincter appeared, the anal canal will be tense. The tense degree of the anal canal could be demonstrated by Anal Canal Rest Pressure (ACRP). So the author classified the muscle strength of the external anal sphincter in quantization, and applied them in the convalescent period of spine cord injury to observe the value in the assessment of the spine cord injury; At the same time, the author measured the Anal Canal Rest Pressure before and after the lumbar anesthesia, and analysis the relationship between ACRP and other measured value for Anal Canal Endometrium Reflex (ACER), Bulbocavernosus Reflex (BR) and the ASIA score.Methods: 70 patients were included in this study, they need to be operated under lumbar anesthesia and without spine cord disease or anal disease. All the patients were divided into two group: one is the External Anal Sphincter (EAS) group including 20patients; the other is the Anal Canal Rest Pressure (ACRP) group including 50 patients. The patients were pricked and injected the narcotic under routine method of lumbar anesthesia. The pricking position is L2/3 or L3/4 intervertebral disc, and the narcotic is 0.75% bupivacaine 15mg. After injection raise the head and put down the foot to make 15°compare to the horizontal line. When the narcotic produce a marked effect let patients lie on the side for measuring.1 The External Anal Sphincter (EAS) group, measured the muscle strength of the external anal sphincter in all the patients, and recorded the ASIA score of the sense and the motion (below the L2 level) according to the ASIA evaluation criterion respectively. They were observed before anesthesia, 5min after anesthesia, 1hour after anesthesia, 1.5hour after anesthesia,. 2hour after anesthesia, and one time every 1hour until recover to the level before anesthesia, 10times in all. The recover order of the spinal cord function in the extinction process of anesthesia and the relationship among them were compared each other.2 The Anal Canal Rest Pressure (ACRP) group, measured the Anal Canal Rest Pressure, the maximum contractive pressure of Anal Canal Endometrium Reflex (ACER), the maximum contractive pressure of Bulbocavernosus Reflex (BR), and recorded the total ASIA score of the sense and the motion (below the L2 level) according to the ASIA evaluation criterion. They were observed before anesthesia, 5min after anesthesia, 0.5hour after anesthesia, and one time every 0.5hour until 5hour after anesthesia, 10times in all. The recover order and recover speed of the spinal cord function in the extinction process of anesthesia and the relationship among them were compared each other.Result: In the EAS group we found that: The muscle strength of the external anal sphincter had a positive correlation with ASIA score of sense and ASIA score of motion in the extinction process of anesthesia. As the function of the spine cord improved, the muscle strength of the external anal sphincter increased too. Just the recover time was fall behind ASIA score of sense and ASIA score of motion. The muscle strength of the external anal sphincter could reflex the function state of the spine cord partly.In the ACRP group we found that: the Anal Canal Rest Pressure was 60mmHg in normal adults. When the lumbar anesthesia produce effect thoroughly, the low spinal cord centre and the cauda eguina nerve were inhibited, the anal canal was relax and the ACRP was 20mmHg, the ASIA score, the maximum contractive pressure of ACER and the maximum contractive pressure of BR were zero. As the recovery of the function of the spine cord and the cauda eguina nerve, the ACRP, ASIA score, ACER and the BR were experience a similar recovery process from weak to strong in the extinction process of anesthesia. Compared to ACER and BR, the ACRP was recovered earlier in the recovery process of the lumbar anesthesia. The ACRP had a positive correlation with the ASIA score, ACER and BR. The ACRP could reflex the change of the ASIA score, ACER and the BR partly.Conclusion: The contraction strength of the external anal sphincter has grade, and it correlated intimately with the nervous function. The muscle strength of the external anal sphincter could reflex the change of the nervous function. The ACRP has a positive correlation with the ASIA score. it is most sensitive to recovery of the nervous function, and reflex the change of the nervous function promptly.