目的 观察电刺激对家兔食管运动的作用,初步探讨如何达成食管有效收缩和蠕动及其所需的最佳程序电刺激参数.方法 健康家兔24只,麻醉后延腹正中线开腹,暴露食管下段,应用多通道信号发生器发出电刺激,高分辨率食管测压仪(HRM)监测食管压力及食管收缩宽度(食管单次收缩累及的范围)变化.(1)探讨不同参数单点电刺激对食管体部压力及食管下括约肌(LES)收缩压力的影响,刺激模式:电流3、5、8 mA,频率5、10、20 Hz,脉宽0.25、25、50 ms,波形双相、单相方波.(2)多点程序电刺激食管,刺激模式:5 mA、20 Hz、脉宽25 ms,刺激时间为3 s,波形为单相方波.结果 电刺激家兔食管体部及LES,食管收缩延迟时间分别为(13.00±1.54)ms、(12.00±0.73)ms.食管体部压力(刺激前后压力差值)与电流(R=0.968,P<0.01)、脉宽(R=0.971,P<0.01)、频率(R=0.947,P<0.01)之间呈正相关;10 Hz组食管体部收缩宽度小于20 Hz组[(1.33±0.06)cm 比(1.80±0.00)cm,P<0.05].LES收缩压与电流(R=0.965,P<0.01)、脉宽(R=0.973,P<0.01)、频率(R=0.842,P<0.01)之间也呈正相关;单相方波LES收缩较双相方波明显(P<0.05).相同参数电刺激下,LES收缩压小于食管体部[ (27.33±1.15) mmHg 比(104.00±6.00) mmHg,P<0.05 ] (1 mmHg=0.133 kPa).多点程序电刺激食管后出现顺序收缩.结论 单点电刺激食管可引起一定宽度的收缩并且几乎没有收缩延迟.在一定范围内,食管收缩压力与电流、频率、脉宽成正比.其它参数相同,单相方波诱发LES收缩压力高于双相方波.食管体部电刺激后收缩压力值高于LES.多点程序电刺激食管可引起顺序收缩.
Objective To observe the effect of electrical stimulation on the movement of rabbits esophagus, and to promote effective esophageal peristalsis and determine the best electrical pacing parameters. Methods After anesthesia, 24 healthy rabbits underwent open surgery and the lower esophagus was exposed. The esophagus was stimulated with the multi-channel signal generator, and the changes of esophagus pressure and the length of esophageal contraction with high resolution manometry were recorded. (1) The effects on contraction pressure of esophagus body and lower esophageal sphincter (LES) after single site electrical stimulation under different parameters were observed. The stimulation modes utilized were electric current 3 mA, 5 mA and 8 mA, frequency 5 Hz, 10 Hz and 20 Hz, pulsewidth 0. 25 ms, 25 ms and 50 ms, waveform of single phase and double phase. (2) The esophagus was sequentially stimulated. The stimulation mode utilized was electric current 5 mA, frequency 20 Hz, pulsewidth 25 ms, stimulation duration 3 s, single phase square wave. Results At electrical stimulation on the esophagus body and LES, contraction delay was 13. 00±1. 54 ms and 12. 00±0. 73 ms respectively. The contraction pressure of esophageal body was significantly positively related tothe electric current (R=0. 968, P<0. 01), the pulse width(R=0. 971, P<0. 01), and the frequency (R =0. 947, P <0. 01). The length of contraction in 10 Hz group was shorter than that of the 20 Hz group(1. 33±0. 06 cm VS 1. 80±0. 00 cm, P<0. 05). The contraction pressure of LES was also significantly positively related to the electric current(R=0. 965, P<0. 01),the pulse width (R=0. 973, P<0. 01), and the frequency (R=0. 842, P<0. 01). The pressure of lower esophageal sphincter of single phase square wave was greater than that of the double phase square group (P<0. 05). Under the same parameters, the contraction pressure of LES group was lower than that of the esophageal body group (27. 33±1. 15 mmHg VS 104. 00±6. 00 mmHg, P<0. 05). Esophageal sequential contraction was induced by multi-points sequential electrical stimulation. Conclusion Single point electric stimulation can cause esophageal contraction immediately without obvious delay. Within a certain range, the esophageal contraction pressure is positively correlated with electric current, frequency and pulse width. The contraction pressure of single square phase wave is greater than that of the double square phase wave. The contraction pressure of esophageal body is greater than that of LES after electric stimulation. Multi-points sequential electrical stimulation can promote sequential movement of esophagus.