Basic and Clinical investigation for disordered defecation after low anterior resection

直肠前切除术(AR)加淋巴结清扫术后，即使在肛门直肠功能恢复后，也经常观察到排便习惯的改变，可能是由于术后结肠运动的改变。本研究旨在探讨外源性自主神经损伤程度与结肠动力变化的关系。[方法]12只杂种犬随机分为4组，分别在结肠植入5个浆膜电极。A组从肠系膜动脉尾段至盆腔水平失神经支配腹主动脉旁和骶前区，包括腹下神经和盆丛。B组从颈总动脉中轴至髂动脉分叉处的腹主动脉旁区域失神经。C组采用沿颈总动脉至腹膜反射边缘动脉切断肠系膜的方法去神经。D组仅植入电极。肌电图仪…在消化间期30分钟和经胃造口术注射橄榄油后120分钟内，持续监测到较多的食欲活动。每隔10min计数连续电反应活动(CERA)和收缩电复合波(CEC)数。[结果]术后3周，A组(2.2&lt；plus-minus&gt；0.72，3.4&lt；plus-minus&gt；1.12，组注射橄榄油后20~30分钟和30~40分钟的结肠CERA和CEC分别小于D(10.6&lt；plus-minus&gt；1.97，10.8&lt；plus-minus&gt；2.24).组(P<0.05)；这种差异即使在右侧结肠也存在(A组：0.4&lt；plus-minus&gt；0.28，0.6&lt；plus-minus&gt；0.40；D组：4.3&lt；plus-minus&gt；0.98，4.3&lt；plus-minus&gt；0.91；P&lt；0.05)。B组(8.8±1.87)和C组(7.6±1.45)消化间期CERA和CEC较D组(5.2±0.83)显著升高(P<0.05)。术后4个月，B组和C组结肠动力恢复至D组水平，但A组(0.8&lt；)右侧结肠动力仍较低。正负3.32，0.4；正负3.32；p&lt；0.05)。[结论]盆丛在结肠运动中起重要作用，甚至对右侧结肠也起重要作用。副交感神经突触前神经元的损伤至少在失神经后4个月才能恢复。提示盆丛损伤可能导致AR后排便习惯的改变。

After anterior resection of the rectum (AR) with lymph node dissection, change in bowel habit is often observed even after recovery of the anorectal function possibly due to changes in colonic motility after the operation. This study was to investigate the relationship between the degrees of extrinsic autonomic nerve injury and the changes in colonic motility. [Methods] Twelve mongrel dogs were equally divided into four groups and underwent implantation of 5 serosal electrodes on the colon. Group A had denervation of autonomic nerves in the paraaortic and presacral regions, including hypogastric nerve and pelvic plexus, from the level of the axis of the caudal mesenteric artery (CMA) to the pelvic space. Group B had denervation in the paraaortic region from the axis of the CMA to the bifurcation of the iliac artery. Group C had denervation by dividing the mesocolon along the marginal artery from the CMA to the peritoneal reflection. Group D had only electrode implantation. Electromyogr … More aphic activity was measured continuously during 30 minutes in interdigestive state and 120 minutes after injection of olive oil through gastrostomy. The number of continuous electrical response activity (CERA) and contractile electrical complex (CEC) were counted in every ten minutes. [Results] Three weeks after the operation, colonic CERA and CEC in the period from 20 to 30 and 30 to 40 minutes after the olive oil injection was smaller (p<0.05) in Group A (2.2<plus-minus>0.72,3.4<plus-minus>1.12, respectively ; mean<plus-minus>SEM) than in Group D(10.6<plus-minus>1.97,10.8<plus-minus>2.24). This difference was present even in the right-sided colon (Group A : 0.4<plus-minus>0.28,0.6<plus-minus>0.40 ; Group D : 4.3<plus-minus>0.98,4.3<plus-minus>0.91 ; p<0.05). On the other hands, CERA and CEC in the interdigestive state in Group B (8.8<plus-minus>1.87)and C(7.6<plus-minus>1.45) were increased (p<0.05) as compared with Group D (5.2<plus-minus>0.83).Four months after the operation, increased colonic motility in Group B and C returned to the level of Group D,but the low colonic motility was still observed in the right-sided colon in Group A (0.8<plus-minus>3.32,0.4<plus-minus>3.32 ; p<0.05). [Conclusions] Pelvic plexus plays an important role in colonic motility even of the right-sided colon. The damage to theparasympathetic presynaptic neurons did not recover at least until 4 months after denervation. These data suggest that the pelvic plexus injury may cause the change in bowel habit after AR Less