肛提肌标识在直肠癌腹会阴联合切除术中的作用

Effects of levator ani muscle exposure in abdominal perineal resection for rectal cancer

目的 探讨肛提肌标识在直肠癌腹会阴联合切除术中的作用.方法 回顾性分析2001年1月至2008年1月南京医科大学第一附属医院收治的109例直肠癌患者的临床资料,其中55例采用传统方法手术（传统法组）,54例采用肛提肌标识法进行手术（肛提肌标识法组）.手术遵循直肠癌全系膜切除术原则,锐性分离直肠系膜,整块切除.两组患者术前肠道准备、麻醉选择、患者体位、腹部切口、会阴部切口、会阴部缝合与Miles术相同.传统法组用电刀或超声刀切开会阴部脂肪组织,自尾骨的前方进入盆腔,与腹部手术医师会合,靠近盆壁切断两侧肛提肌未进行标识则进行后续手术操作.肛提肌标识法组采用电刀切开肛门周围间隙脂肪组织,分离两侧坐骨肛管间隙脂肪组织,切断后方肛尾韧带,直达肛提肌平面,标识肛提肌后进行后续手术操作.术后病理检查为Ⅰ期者进行随访观察;术后病理检查为Ⅱ期者,如组织学分化差、T4期、血管淋巴管浸润、检出淋巴结数目＜12枚,则行辅助化疗,如无则进行随访观察;术后病理检查为Ⅲ、Ⅳ期者,行术后化疗.术后第1年,每3个月复查1次血常规、肝肾功能、胸部X线片和肝胆B超.1年后每6个月复查1次上述检查;每年复查1次CT和肠镜检查.随访时间截至2012年12月.计数资料采用x2检验,计量资料采用t检验,Kaplan-Meier法绘制生存曲线,生存率比较采用Log-rank检验.结果 两组患者顺利完成手术,传统法组患者和肛提肌标识法组患者的会阴手术时间分别为（60±15） min和（30±10） min,术中出血量分别为（300 ±60） mL和（30±20） mL,两组比较,差异有统计学意义（t=3.936,5.687,P＜0.05）.传统法组患者中,3例直肠破损,2例尿道（阴道）破损,10例切口感染;而肛提肌标识法组患者中,只有9例切口感染.109例患者中,术后化疗周期少于12个疗程者30例,6个疗程及以上者41例.中位随访时间为56个月（15 ～95个月）.109例患者中,10例失访,15例局部复发,30例远处转移,35例死亡.1、3、5年累积生存率分别为93.4％、76.0％、65.6％.传统法组和肛提肌标识法组患者5年生存率分别为65.2％和66.3％,两组比较,差异无统计学意义（x2=4.210,P＞0.05）.结论 在直肠癌腹会阴联合切除术中,与传统手术方法比较,肛提肌标识法手术解剖清晰,视野好,手术时间短,术中出血量少,不易误伤直肠或尿道（阴道）.

Objective To investigate the effects of levator ani muscle exposure in abdominal periueal resection for rectal cancer.Methods The clinical data of 109 patients with rectal cancer who were admitted to the First Affiliated Hospital of Nanjing Medical University from January 2001 to January 2008 were retrospectively analyzed.There were 55 patients received traditional procedure （conventional method group） and 54 patients received modified procedure with levator ani muscle exposure （levator ani muscle exposure group）.The mesorectum was sharply dissected according to the total mesorectal excision principle.It is essential to remove the rectum along with the mesorectum up to the level of the levators.Preoperative bowel preparation,anesthesia,body position,abdominal incision,perineal incision and suture of the 2 groups were the same as Miles procedure.In the conventional method group,the superficial dissection was carried out with electrocautery or ultracision harmonic scalpel.The presacral space was entered by dividing the rectococcygeus muscle,commencing at the level of the tip of the coccygeus.The levators were then divided near the pelvic wall attachments and next procedures were performed without levator ani muscle exposure.In levator ani muscle exposure group,once the ischiorectal fat was cleared by electrocautery,the planes of levator ani muscle were identified and exposed after dividing the rectococcygeus muscle and next procedures were performed.The patients in stage Ⅰ only needed to follow-up; the patients in stage Ⅱ had to receive chemotherapy with following situation：poor differentiation,T4 stage,blood vessel or lymphatic invasion,number of lymph nodcs detected 〈 12.Patients in stage Ⅲ or Ⅳ needed adjuvant chemotherapy.The follow-up evaluation included blood routine examination,hepatic and renal function examination,chest radiography,hepatobiliary ultrasonographic evaluation and determination of CEA levels （once every 3 months in the first year after operation,and once every 6 months after one year）.Abdominal CT scan and colonoscopy should be employed every year.All the patients were followed up till December of 2012.All data were analyzed using the chi-square test or t test.The survival curve was drawn using the Kaplan-Meier method,and the prognosis was analyzed using the Log-rank test.Results The operation time were （60 ± 15）minutes and （30 ± 10） minutes in the conventional method group and the levator ani muscle exposure group,with significant difference between the 2 groups （t =3.936,P 〈 0.05）.The intraoperative blood loss were （300 ± 60） mL and （30±20） mL in the conventional method group and the levator ani muscle exposure group,with significant difference between the 2 groups （t =5.687,P 〈 0.05）.Three patients were with rectal injury,1 with urethral injury,1 with vaginal injury,and 10 with incision infection in the conventional method group.There were 9 patients with incision infection in the levator ani muscle exposure group.The course of chemotherapy was under 12 in 30 patients,and above 6 in 41 patients.The median time of follow-up of the patients was 56 months （range,15-95 months）.Of the 109 patients,10 missed the follow-up,15 patients had local recurrence,30 had distal metastasis,and 35 patients died.The 1-,3-,5-year cumulative survival rates were 93.4%,76.0% and 65.6%.The 5-year survival rates were 65.2% and 66.3% for patients in the conventional method group and the levator ani muscle exposure group,with no significant difference between the 2 groups （x2=4.210,P 〉0.05）.Conclusion Levator ani muscle exposure method provides clearer vision of operational field,shorter operation time,less blood loss and less injury to the rectum or urinary tract （vagina）.