| Abstract: | 逼尿肌外括約肌共濟失調是脊髓損傷患者常見的膀胱功能障礙，且是造成這些病患後續泌尿系統併發症的主要原因。括約肌切開術是目前認為較有效的方法，但是它的高失敗率和再開刀率及不可逆性，使此療法仍無法被廣泛接受。其他治療方法包括尿道支架，氣球擴張術，口服藥物，陰部神經阻斷術，手指肛門擴張和肉毒桿菌毒素注射等。在這些療法中，肛門擴張和肉毒桿菌注射於尿道外括約肌是相對安全、副作用少且容易施行的治療。肛門擴張在前人的研究中，可以有效降低尿道外括約肌的張力，但對於逼尿肌的影響，卻有不同的看法，且自1981年以來，並沒有更進一步的研究。肉毒桿菌毒素注射在尿道括約肌上，可以減少病人的殘尿量和降低病人的逼尿肌壓力和尿道壓力，然而這些參數只能間接測量尿道外括約肌的活動度，且可能會受到其他因素的影響。肌電圖可以直接測量尿道外括約肌的活動度，但在前人的研究中，只有描述性的紀錄，並沒有做定量評估。.在本研究中，我們希望對這兩種治療方法作進一步的研究，並以整合式肌電圖定量尿道外括約肌的變化，希望以定量的方式評估療效，並以此找出適合此療法的病患已增加臨床效益。肛門擴張的研究結果為，尿道外括約肌的整合式肌電圖在擴張後有明顯降低（擴張後1-15秒和16-30秒分別降低33％和35％）。尿道壓力則在擴張後16-30秒才有明顯降低。逼尿肌壓力則無明顯差異。不同ASIA impairment scale的病人，對肛門擴張的反應也不一樣：脊髓損傷越完全的病人，肛門擴張的效果越好。肉毒桿菌毒素注射研究的結果為，病人治療後一個月的整合式肌電圖，尿道壓力檢查的最大尿道壓和膀胱灌流檢查的最大尿道壓均有明顯降低（降低百分比分別為24.4％, 20.6％和17.3％），但最大逼尿肌收縮壓和膀胱漏尿壓力均沒有改變。在注射後的一、二、三、和六個月後，病人的平均殘尿量均有明顯降低（降低百分比為41.2％, 32.6％, 24.6％和15.8％）。當我們進一步分析療效好和療效差的病人之間的差異，發現療效好病人組的治療前整合式肌電圖數據較低。總結來說，整合式肌電圖對於評估這兩種治療方法的療效是個很好的工具。它可以定量尿道外括約肌的活動度，直接看到治療後的變化，且可以進一步做分層分析，協助找出適合某種療法的病人，以增加治療的效益。
Detrusor-external sphincter dyssynergia (DESD) is a common cause of bladder outlet obstruction in SCI patients and associated with many urologic complications. Sphincterotomy is currently the main treatment of DESD, but its irreversability, high failure rate and high re-operation rate make it not so acceptable to most SCI patients. The other treatment choices are urethral stent, urethral ballon dilatation, oral medication, pudendal nerve block, anal stretch and botulinum toxin injection.
Among these methods, anal stretch and botulinum toxin injection are two methods that are reversible, easy to perform, and with no serious side effects. Anal stretch was reported to effectively inhibit activity of external urethral sphincter in patients with DESD. However the opinions of effects on detrusor are controversial and there were no further studies since 1981. Botulinum –A toxin injection to the external urethral sphincter could reduce post-voiding residual urine amounts and improve urodynamic parameters (detrusor pressure and urethral pressure) in previous reports. However these parameters could be influenced by other factors and the direct evaluation of urethral sphincter activity from electromyography was only descriptive without quantification in these studies.
In this study, we further investigated these two treatments by using integrated electromyography (IEMG) to quantify the activity of external urethral sphincter. With direct evidences of effect, we could choose the prompt patients to receive these treatments, then we can improve the clinical efficiency.
In the results of anal stretch, it could significantly reduce the activity of external urethral sphincter showed on IEMG (the mediums of reduction percentage during 1- 15 seconds and 16-30 seconds were 33% and 35%). The urethral pressure was also reduced but the difference was significant only between the data before stretch and at 16-30 seconds after stretch. The detrusor pressure did not change significantly. Patients with different ASIA impairment scale had different responses: the more completeness of neurologic injury (Grade A and B in ASIA impairment scale), the better effect of anal stretch.
In the results of botulinum toxin injection, there were significant reductions in IEMG and static and dynamic urethral pressure (mean reduction percentages were 24.4, 20.6, and 17.3, respectively) but not in maximal detrusor pressure and leak point pressure at one month after treatment. PVR was significantly decreased at the all of the evaluation periods (mean reduction percentages were 41.2, 32.6, 24.6, and 15.8, at month 1, 2, 3, and 6 after treatment). In the sub-group analysis, patients with good effect had significantly lower baseline IEMG (p<0.05).
In conclusions, IEMG is a good tool to evaluate the effect of anal stretch and botulinum toxin injection in treating DESD. It could quantify the activity of external urethral sphincter thus we could know the net effect of these interventions. Besides, it could also help in subgroup analysis that we could decide the suitable subjects for a specific treatment. |
