Mesorectal excision: Surgical anatomy of the rectum, mesorectum, and pelvic fascia and nerves and clinical relevance

Biologic behavior and management of rectal cancer differ significantly from that of colon cancer. The surgical treatment is challenging since the rectum has dual arterial blood supply and venous drainage, extensive lymphatic drainage and is located in a bony pelvic in close proximity to urogenital and neurovascular structures that are invested with intricate fascial covering. The rectum is encased byfatty lymphovascular tissue(mesorectum) that is surrounded by perirectal fascia that act as barrier to the spread of the cancer and constitute the surgical circumferential margin. Locoregional recurrence after rectal cancer surgery is influenced by tumor-related factors and adequacy of the resection. Local recurrence is associated with incomplete excision of circumferential margin, violation of perirectal fascia, transmesorectal dissection, presence of isolated deposits in the mesorectum and tumor in regional lymph nodes and incomplete lymph node clearance. Hence to eradicate the primary rectal tumor and control regional disease, the rectum, first area of lymph node drainage and surrounding tissue must be completely excised while maintaining an intact fascial envelope around the rectum and preserving surrounding structures. This is achieved with extrafascial dissection and removal of the entire mesorectum including the portion distal to the tumor(total mesorectal excision) within its enveloping fascia as an intact unit. Total mesorectal excision is the standard of care surgical treatment of mid and low rectal cancer and can be performed in conjunction with low anterior resection,abdominoperineal resection, extralevator abdominoperineal resection, and extraregional dissection. To accomplish such a resection, thorough knowledge of the surgical anatomy of the rectum and pelvic structures and fascial planes is paramount.

Mesorectum localization as a special kind of rectal metastasis from breast cancer

Breast cancer can metastasize to other organs following initial treatment.Bones, liver, and the lung are the most common sites of breast cancer metastases.The digestive tract, on the other hand, is rarely involved.The incidence of mesorectal metastasis(a special category of rectal metastases) from breast cancer has not been described before.The case reported herein concerns a 68-year-old woman who underwent mastectomy.A pelvic mass with no symptoms was subsequently identified by computed tomography in the patient.We ultimately confirmed that this mass was a metastasis from breast cancer located in the mesorectum using surgical exploration and pathology results.

Nodal spread and micrometastasis within mesorectum

AIM: To study the distribution of positive lymph nodes within mesorectum and to investigate the possible micrometastasis in negative lymph nodes. METHODS: Large slice technique combined with tissue microarray was used in the pathologic study of 31 specimens.RESULTS: A total of 992 lymph nodes were harvested and cancer metastasis was found in 148 lymph nodes. Some positive lymph nodes were located in the outer layer of mesorectum and more at the same site of mesorectum as the primary tumor. Circumferential margin lymph node metastasis was observed in nine cases. No significant difference in occurrence of micrometastasis was observed in different stage tumors. CONCLUSION: Positive lymph nodes are distributed in mesorectum and micrometastasis can be found in negative lymph nodes.

Morphology of the anterior mesorectum:a new predictor for local recurrence in patients with rectal cancer

Background:Pre-operative assessment with high-resolution magnetic resonance imaging(MRI)is useful for assessing the risk of local recurrence(LR)and survival in rectal cancer.However,few studies have explored the clinical importance of the morphology of the anterior mesorectum,especially in patients with anterior cancer.Hence,the study aimed to investigate the impact of the morphology of the anterior mesorectum on LR in patients with primary rectal cancer.Methods:A retrospective study was performed on 176 patients who underwent neoadjuvant treatment and curative-intent surgery.Patients were divided into two groups according to the morphology of the anterior mesorectum on sagittal MRI:(1)linear type:the anterior mesorectum was thin and linear;and(2)triangular type:the anterior mesorectum was thick and had a unique triangular shape.Clinicopathological and LR data were compared between patients with linear type anterior mesorectal morphology and patients with triangular type anterior mesorectal morphology.Results:Morphometric analysis showed that 90(51.1%)patients had linear type anterior mesorectal morphology,while 86(48.9%)had triangular type anterior mesorectal morphology.Compared to triangular type anterior mesorectal morphology,linear type anterior mesorectal morphology was more common in females and was associated with a higher risk of circumferential resection margin involvement measured by MRI(35.6%[32/90]vs.16.3%[14/86],P=0.004)and a higher 5-year LR rate(12.2%vs.3.5%,P=0.030).In addition,the combination of linear type anterior mesorectal morphology and anterior tumors was confirmed as an independent risk factor for LR(odds ratio=4.283,P=0.014).Conclusions:The classification established in this study was a simple way to describe morphological characteristics of the anterior mesorectum.The combination of linear type anterior mesorectal morphology and anterior tumors was an independent risk factor for LR and may act as a tool to assist with LR risk stratification and treatment selection.

直肠系膜结构解剖和腔镜下观察的对比研究

【目的】通过尸体解剖和手术录像对比研究直肠系膜、Denonvilliers筋膜、直肠侧韧带、直肠系膜周围间隙等结构的解剖特点,进一步了解全直肠系膜切除(TME)解剖根据。【方法】对5具成人男性尸体标本,进行解剖;复习我科腹腔镜全直肠系膜切除治疗的10例中低位直肠癌男性患者手术录像资料。进行尸体和腔镜下直肠系膜结构的对比研究。【结果】盆脏筋膜包绕直肠周围脂肪结缔组织、淋巴组织、供应直肠血管回流血管和神经等形成直肠系膜。而盆脏筋膜与盆壁筋膜之间有层疏松结缔组织,在直肠后方明显。直肠侧方盆腔自主神经分支形成致密类筋膜结构——侧韧带,而直肠前方位于Denonvilliers筋膜的后方,呈环周状包绕直肠的固有筋膜。【结论】大多数情况下,除了侧方的侧韧带,行TME正确的层面是无血管的疏松结缔组织层。游离过程应紧贴直肠系膜,保证系膜完整性,减少盆腔自主神经损伤。

直肠系膜的形态学特点及其临床意义

目的:以直肠系膜为中心,探讨直肠癌手术切除术的最佳的解剖层次。方法:应用尸体标本27例、新鲜尸体标本10例、临床取材标本10例,分别进行解剖、测量及灌注。结果:直肠系膜是由直肠周围包裹在盆脏筋膜周围之内的脂肪组织、神经、血管、淋巴管等组成。直肠系膜上端与乙状结肠系膜相连续,下端与直肠肛管相连接,盆腔内的生殖管道,髂内血管,盆自主神经及盆腔侧壁的肌肉均为壁层筋膜覆盖,外面是一层光滑的盆脏筋膜,长8￣10cm,宽6￣8cm,直视下清晰可见脂肪、毛细血管等。结论:直肠系膜是被盆筋膜脏层完整地包裹着的脂肪、血管和淋巴即称为直肠系膜,是一独立的解剖单位;从常规病理可见直肠系膜是由脂肪、血管和淋巴组织组成;MRI及VCH上直肠系膜清晰可见。

直肠癌直肠系膜解剖及其临床意义

目的 研究直肠癌直肠系膜的结构及其在直肠癌手术中的意义。方法 解剖本院近2 年来72 例直肠癌术后的新鲜标本,测量肠系膜下动脉的长度;观察直肠系膜结构、肠系膜下动脉分支及肿大淋巴结情况;病理检查送检淋巴结、系膜边缘及肠残端。结果 直肠系膜内的淋巴结主要集中于直肠肿瘤周围2 cm区域,直肠上动脉分叉处,肠系膜下动脉根部3 个区域,各区域淋巴结阳性率为78.6%、34.3%、8.9%,而直肠反折上肿瘤各区淋巴结阳性率79.8%、40.5%、23.7%。但左结肠动脉到直肠上动脉分叉处的较长沿途中,淋巴结肿大、转移极少, 直肠系膜呈中厚侧薄的结构,直肠下端近隔膜处的裸区实质上就是直肠下端直肠系膜与直肠之间通过疏松结缔组织相连的区域,并不是真正的裸区。结论 直肠癌D3 手术高位结扎肠系膜下动脉是完全必要的,手术时最下一支的乙状结肠动脉及其所供血的结肠可作为直肠癌切除的上切缘,“裸区”存在对低位及超低位直肠癌保肛手术有重要意义。

直肠癌全直肠系膜切除经腹腔镜与开腹手术的临床对照研究

目的 :探讨经腹腔镜行全直肠系膜切除的可行性。方法 :36例直肠癌患者分别采用经腹腔镜或常规开腹手术行直肠癌根治术 ,比较两组围手术期的情况与切除标本 ,了解肿瘤切除的彻底性 ,肠旁淋巴结清扫数量的差异。结果 :两组切除标本的直肠系膜均完整 ;腹腔镜组与开腹组淋巴结数分别为 7 9± 0 7与 8 1± 0 9(P >0 0 5 ) ;直肠远切端均无癌细胞浸润 ;腹腔镜组失血 136± 2 1ml ,开腹组失血 35 7± 34ml,差异有高度显著性 (P <0 0 1) ,腹腔镜组手术后肠功能恢复早 (4 3± 5hvs 78± 12h ,P <0 0 5 ) ,围手术期并发症 2组无显著差别。结论 :在熟练掌握开腹全直肠系膜切除 (TME)的基础上经腹腔镜行TME是可行的 ,且患者创伤小、康复快 。

大组织切片研究直肠癌在直肠系膜内及环周切缘的播散

目的 研究直肠癌在直肠系膜内及环周切缘的播散转移规律 ,为合理施行直肠癌手术提供病理学证据。方法 对 6 2例直肠癌患者行全直肠系膜切除术 (TME) ,手术标本制作直肠及全层系膜大组织切片 ,HE染色 ,显微镜观察。结果 期病例中 ,直肠系膜外带 (左、后、右三区 )癌灶占 4 3.2 4 %。直肠侧壁肿瘤 ,系膜同侧癌灶多于对侧 (P<0 .0 5 )。远端直肠系膜内癌播散距原发灶 1～ 3.5 cm,均为 TNM 、 期患者 ,发生率为 12 .9% (8/6 2 )。肿瘤环周切缘癌浸润 (CMI)与肿瘤分化及 TNM分期相关 ,直肠不同部位 CMI发生率无明显差别 (P>0 .0 5 )。结论利用大组织切片技术 ,能够全面观察直肠、直肠系膜及其癌灶分布。系膜外带及肿瘤同侧系膜内癌灶分布较多。手术应完整切除肿瘤远端 4 cm直肠及其周围系膜。 TME减少了癌残留及环周切缘癌浸润可能 。

直肠癌淋巴结转移规律及其根治术中的合理切除

背景与目的:直肠癌是消化道最为常见的恶性肿瘤之一,淋巴转移是常见的转移途径,也是导致复发而致死亡的重要原因。本研究探讨直肠癌淋巴结转移规律与直肠癌根治术的合理切除范围。方法:2004年9月—2005年9月于本院普外科胃肠专业组的接受直肠癌根治术27例患者,系膜淋巴结及侧方淋巴结分为10组,送检。结果:共取出淋巴结555个,癌浸润99个,其中肿瘤旁267个,癌浸润72个;肿瘤近端165个,癌浸润21个;肿瘤远端75个,无癌浸润;侧方48个,癌浸润6个。44%有淋巴结转移,11%发生侧方淋巴结转移,直肠癌淋巴结转移肿瘤旁为主,癌浸润淋巴结肿瘤旁占72.7%,近端为21.2%,侧方6.06%,肿瘤远端未见癌浸润淋巴结。结论:直肠癌的淋巴转移以肿瘤旁为主,为保肛低位直肠癌远端切除1～2cm是可行的。

直肠癌保肛术后老年患者焦虑及抑郁与生存质量的相关性

目的了解直肠癌保肛术后老年患者焦虑及抑郁与生存质量现状,并探讨其相关性。方法采用自行设计的患者一般资料调查问卷、医院综合焦虑抑郁量表(hospital anxiety and depression scale,HADS)和SF-36健康调查量表(the MOS 36 items short form health survey,SF-36)对60例直肠癌保肛术后老年患者进行调查。患者焦虑及抑郁与生活质量的相关性采用Pearson相关分析。结果直肠癌保肛术后老年患者SF-36总分为(64.20±11.76)分;其焦虑阳性者占36.67%,抑郁阳性者占30.00%。直肠癌保肛术后老年患者焦虑及抑郁与生存质量均呈负相关(r值分别为-0.312和-0.495,均P<0.05)。结论护理人员应积极给予直肠癌保肛术后老年患者心理情感支持,指导其采用放松疗法等措施,以减轻患者焦虑及抑郁情绪,从而提高其生存质量。

Lateral lymph node dissection for low rectal cancer: Is it necessary?

Rectal cancer constitutes a major public health issue.Total mesorectal excision has remained the gold standard treatment for mid and low rectal tumors since its introduction in the late 1980s.Removal of all lymph nodes located in the mesorectum has indeed improved pathological and oncological outcomes.However,when cancer spreads to the lateral lymph nodes(located along the iliac and obturator arteries)Western and Japanese practices differ.Where the Western guidelines consider this condition as an advanced form of the disease and use neoadjuvant radiochemotherapy liberally,the Japanese guidelines define it as a local disease and proceed to lateral lymph node dissection with or without neoadjuvant treatment.Herein,we review the current literature regarding both therapeutic strategies,with the aim of contributing to potential improvements in treatment and outcome for patients with low and mid rectal cancer.

RT-PCR检测直肠癌在直肠系膜的播散范围及临床意义

目的 以CEAmRNA为标记物 ,应用RT PCR技术检测直肠癌在直肠系膜的播散范围 ,以探讨直肠癌根治术直肠系膜的合理切除范围。方法 4 0例直肠癌全系膜切除的手术标本 ,取不同距离的直肠系膜以CEAmRNA为标记物 ,应用RT PCR技术检测其有无癌转移。结果 在 4 0例病例中发现直肠系膜有癌播散者 9例 (2 2 .5 % ) ,播散最远距离在肿瘤下缘下 4cm。直肠癌在直肠系膜的播散与Dukes分期、肿瘤浸润肠壁深度、肿瘤分化程度及肿瘤分型相关 (P<0 .0 5 ) ,与肿瘤大小及CEA水平无明显相关性 (P>0 .0 5 )。结论 直肠癌根治术中距肿瘤下缘 5cm范围是直肠系膜的安全切缘。

直肠末端系膜解剖在直肠癌根治术中的意义

目的 了解直肠末端系膜附着缘的解剖标志及其形态分布对全直肠系膜切除 (TME)手术的影响。方法 收集由同一组医师连续手术切除的 2 2 0例中、低位直肠癌大体标本 ,分为两组。Ⅰ组 (保肛组 ) :又分为Ⅰa组 ,低位直肠前切除术 (LAR术 ) ,81例 ,限直肠癌下缘距肛缘 5～ 6cm者 ;Ⅰb组 ,直肠前切除术 (AR术 ) ,68例 ,限直肠癌下缘距肛缘 7～ 8cm者。Ⅱ组 (切肛组 ) :腹会阴联合直肠切除术 (APR术 ) ,71例 ,限直肠癌下缘距肛缘<5cm者。结果 ①直肠末端系膜环形附着缘位于肛提肌的肛缝以上 1 .0cm肠壁上 ,但该水平恰好与低位直肠癌下缘齐平。因此 ,为了满足 2～ 3cm下切端 ,在肛缝以下分离直肠肌性管道行LAR术时 ,要小心避免损伤肠壁。②直肠末端系膜附着于肠壁上呈环形片状 ,而非环形线状 ,与直肠后壁间仅有少量脂肪组织 ,其纵向附着长度约为 (1 .2 69± 0 .1 71 )cm(LAR组 81例 +APR组 71例 ) ,当行AR术时 ,其下切缘恰好位于系膜的片状附着区内 ,在裸化直肠时 ,要小心谨慎 ,以免损伤肠壁。结论 直肠末端系膜呈环形片状附着于肛提肌的肛缝上 1 .0cm处 ,在行低位或超低位直肠前切除 ,裸化直肠壁时要仔细分离 ,以免损伤肠壁 。

正常直肠系膜和直肠筋膜的MRI表现

目的 :探讨直肠系膜、直肠筋膜的正常MRI表现。方法 :收集无直肠及周围间隙病变的50例患者的临床和MRI资料,在轴位图像上测量并记录:1精囊腺/子宫体平面上,直肠在直肠周围间隙内的解剖位置;2直肠筋膜显示情况及其厚度;3直肠系膜与盆壁脂肪信号强度比值;4直肠系膜内淋巴结显示情况。结果:精囊腺/子宫体平面上,直肠主要位于直肠筋膜构成的直肠周围间隙内的侧方。直肠筋膜最厚处为(1.94±0.54)mm。直肠系膜与盆壁脂肪信号强度比值为1.02±0.17;直肠系膜脂肪信号强度高于盆壁脂肪信号强度(P<0.01)。直肠系膜内正常淋巴结显示率低,其最大径均小于5 mm。结论:MRI能良好显示直肠筋膜及直肠系膜的解剖结构。

腹腔镜低位直肠癌内括约肌切除保肛手术的临床应用

目的：探讨在腹腔镜全直肠系膜切除基础上施行内括约肌切除保肛术治疗低位直肠癌的可行性和疗效。方法：回顾分析2007年4月至2008年6月我院为36例低位直肠癌患者行腹腔镜内括约肌切除保肛术的临床资料。结果：36例顺利完成手术,平均手术时间（110±32）m in,术中平均出血（15±18.5）m l,术后持续胃肠减压8~48h,肠蠕动恢复时间（24±17）h,术后1~3d开始进食,1~3d拔除导尿管下床活动,平均住院8d。术后随访8~20个月,12例出现前切除术后综合征,3~6个月后症状消失,目前未发现转移、复发病例。结论：全系膜切除是根治切除直肠癌必须遵循的原则;腹腔镜内括约肌切除保肛术治疗低位和超低位直肠癌安全可行,患者创伤小,出血少,疼痛轻,康复快。

减少低位直肠癌全直肠系膜切除吻合口瘘的手术策略

目的探讨术中有效减少低位直肠癌全直肠系膜切除吻合口瘘的手段。方法回顾分析本院2002年至2005年58例低位直肠癌行全直肠系膜切除术的临床资料。结果吻合口瘘4例,发生率6.9%,无再次手术病例。结论缩短手术时间、良好的血供、双吻合器、加强缝合、有效盆腔引流是减少吻合口瘘的有效措施。

直肠系膜全切除在直肠癌低位前切除的应用

[目的]探讨直肠系膜全切除在直肠癌低位前切除的应用。[方法]对1995年～2000年收治的进行低位前切除的直肠癌病例共67例进行回顾性分析。[结果]全组共发生吻合口瘘5例 ,发生率为7 %。均行转流性造口而治愈 ,无手术相关死亡。

直肠癌TME术后检测癌组织及直肠系膜内MMP-7的意义

目的:研究直肠癌患者直肠系膜内MMP-7表达,为全直肠系膜切除术(totalmesorectalexcision,TME)提供理论依据.方法:直肠癌TME术后,应用免疫组化SP法检测47例患者癌组织、直肠系膜(肿瘤平面、肿瘤下缘下2cm和系膜远端)及盆筋膜壁层MMP-7的表达.并与病理组织学染色(常规HE染色)结果进行比较.结果:直肠系膜中MMP-7的阳性表达率为29.8%(14/47),有7例患者只在肿瘤平面系膜内有MMP-7表达,3例在肿瘤平面和肿瘤下缘下2cm处系膜内有MMP-7表达,4例只在肿瘤下缘下2cm有MMP-7阳性表达.常规病理染色阳性率为14.8%(7/47),其MMP-7染色均为阳性.在癌组织中,MMP-7的阳性率为91.5%(14/47).在直肠系膜远端、盆筋膜壁层和对照组织(距肿瘤上缘10cm以上的正常直肠黏膜和系膜)中,MMP-7均无表达.结论:直肠系膜内MMP-7表达可及肿瘤平面和肿瘤下缘下2cm处,但尚未达到直肠系膜远端和盆筋膜壁层.肿瘤的分化程度、肠壁浸润深度和Dukes分期与系膜内MMP-7阳性表达有关.从分子病理学的角度可以认为TME是科学的.

直肠系膜的形态结构特点及临床意义

目的:明确直肠系膜的内容、形态学特点及毗邻关系。方法:对35具尸体材料进行解剖,运用大体解剖、组织学、透射电镜和核磁共振等方式进行观察、记录。结果:直肠系膜是包绕在直肠周围的血管、淋巴管、神经及脂肪组织,其上端与乙状结肠系膜相延续,下端在直肠肛管连接处明显变薄后止于该处;在直肠的前腹膜反折以上由腹膜覆盖在盆脏筋膜的外面,反折以下盆脏筋膜的前面有Denonvilliers’筋膜。结论:直肠系膜是包绕在袖套样盆脏筋膜之内(包括盆脏筋膜在内)的直肠周围所有血管、淋巴管和淋巴结、神经及脂肪组织等共同构成的独立解剖结构。