Vascular organization in the mesorectum: angiography of rectal resection specimens

The technical advances in rectal cancer surgery are known as the total mesorectal excision. The resection in an anatomically defined plane under direct vision and with sharp dissection distinguishes it conventional rectal surgery. The result must be a complete mesorectum without deep gouges. We performed specimen angiography to confirm completeness of the removed mesorectum. Thirteen total mesorectal excision specimens were examined by angiography after continence-preserving resection of rectal carcinoma. In 11 of the 13 cases the vascular supply was exclusively via the superior rectal artery. In two cases with hypoplastic left terminating branches of the superior rectal artery there was additional perfusion via a caudally ascending vessel or via smaller vessels connected laterally. In all specimens both arterial supply and venous outflow were located within the mesorectal fascial sheath. There was no radio-opaque substance leaking from the mesorectal surface in the case of a complete mesorectal specimen. Tiny vascular branches running laterally occurred in 7 of the 13 cases. We found no larger vascular connections branching off in the lateral direction. The rectal blood supply comes almost exclusively through the superior rectal vessels. Thus the fascia covering the mesorectum forms, as far as rectal vascularization is concerned, a closed compartment. The mesorectal vessels are enclosed in the fibrous avascular mesorectal fascia. They run close above the fascia. In the case of an incomplete mesorectal excision the specimen angiography shows a stain leaking from the mesorectal fascia. Our method can be used to confirm the completeness of the removed mesorectum.     

Denonvilliers筋膜的微创解剖认识及其临床价值

1836年,法国外科学家Charles-Pierre Denonvilliers首次描述在男性的直肠与膀胱、精囊腺和前列腺之间存在薄层致密组织,后被称为Denonvilliers筋膜。1982年英国外科学家R.J. Heald教授提出全直肠系膜切除术（TME）理念,历经数十年的临床实践,TME已成为中低位直肠癌手术的金标准。根据TME理念,直肠后方及侧方均应在盆筋膜壁层内面与直肠固有筋膜间分离,而在直肠前方于Denonvilliers筋膜前方分离、肿瘤下方2 cm处倒U形离断并切除部分Denonvilliers筋膜。然而,资料显示,由于盆腔自主神经（PAN）的损伤,TME术后排尿及性功能障碍发生率居高不下。因此,进一步理清盆腔筋膜和自主神经解剖的认识,对于改善患者术后功能尤为重要。在国内外众多学者研究的基础上,我们从胚胎发育学、解剖学、组织学和外科手术角度对盆腔筋膜及外科层面进行深入探索,指出Denonvilliers筋膜不属于直肠固有筋膜的范畴、如非肿瘤浸润应予保留,并提出保留Denonvilliers筋膜全直肠系膜切除术（iTME）的理念;并采用多中心临床试验加以验证。在此基础上我们联合国内直肠癌外科领域专家,发布iTME中国专家共识,旨在提高从业者对神经功能保护的认识,规范手术操作,造福广大患者。     

Total mesorectal excision and preservation of autonomic nerves]

The procedure of total mesorectal excision (TME) becomes a gold standard for the treatment of rectal cancer. The reason is the marvelously low incidence of local recurrence after TME even without other adjuvant treatment, which has been reported by several independent groups. Although controversy still exists about the role of TME in upper rectal cancer, it is now widely accepted for cancers of the middle and lower third. There are number of histopathological evidences that cancer cells can spread distally several centimeters from the lower margin of cancer, and cancer bearing lymph nodes are found in the distal portion of the mesorectal tissues far from the cancer. Therefore, the distal clearance of mesorectum should be performed downwardly to the level of pelvic diaphragm (puborectalis) and the rectum is divided within a few centimeters from the pelvic floor musculature. TME defines an en-bloc procedure, along the plane between parietal and visceral pelvic fasciae. If the dissection plane is breached, the chance of visceral pelvic fascia tearing is raised and mesorectal tissue might reside in the pelvis. There are problems in auditing the procedure. As many surgeons agree, this procedure requires a learning curve. Theoretically, the autonomic nerves run between the visceral and parietal pelvic fasciae since the nerves must be preserved to make visceral fascial envelop. Any patient who become incontinent or impotent after the surgery should have received decorticating surgery other than TME. Thus, the high quality of TME should fulfill two clinical measurements: absence of impotence or incontinence and at least single digit, 5-year, cumulative recurrence rate regardless of adjuvant therapy.     

直肠癌全直肠系膜切除术中盆腔植物神经的易损区域及保护

全直肠系膜切除术（TME）是目前国际公认的直肠癌标准术式,随着TME手术的推广和认识,盆腔植物神经保护（PANP）的理念逐渐受到重视。笔者认为,在开展直肠癌TME手术时,有六个区域容易发生盆腔植物神经损伤,需要识别和保护：肠系膜下动脉根部的肠系膜下丛、上腹下神经丛及腹下神经的近端、盆丛前丛的近端、盆丛后丛的主干、盆丛后丛的终末支及盆腔内脏神经。熟悉盆腔筋膜、植物神经解剖,开展以TME手术层面为主导,盆腔植物神经为引导的精准直肠癌手术,对于提高手术质量,保护器官功能至关重要。     

间介中胚层、泌尿-生殖层与直肠周围筋膜

由胚胎期间介中胚层-泄殖腔发育形成了一个包含肾脏（肾周脂肪）、输尿管、生殖血管并延续包含膀胱、输精管、精囊腺、前列腺等泌尿、生殖器官的功能层面,我们命名为"泌尿-生殖层",其表面的内脏筋膜是泌尿-生殖筋膜。直肠周围被泌尿-生殖层所围绕,泌尿-生殖筋膜脏层构成了直肠周围筋膜,直肠固有筋膜与泌尿-生殖筋膜脏层之间形成直肠周围间隙。直肠中、下段全系膜切除的游离平面跨越了泌尿-生殖层,前后游离平面的交汇点在直肠侧方结构。     

腹腔镜下直肠癌根治术保留自主神经的解剖和技术要点

全直肠系膜切除术（TME）是目前国际公认的直肠癌标准术式,随着腹腔镜技术的推广和TME手术的普及,盆腔植物神经保护（PANP）的理念逐渐受到重视。本文根据作者经验和结合国内外文献,介绍保留PANP相关的新认识和技术进展。笔者认为,在开展直肠癌TME手术时,有六个部位容易发生盆腔植物神经损伤,需要识别和保护：肠系膜下动脉根部的肠系膜下丛,上腹下神经丛及腹下神经的近端,盆丛前丛的近端,盆丛后丛的主干,盆丛后丛的终末支,盆腔内脏神经以及血管神经束（NVB）。要完整保留PANP,需要熟悉盆腔筋膜解剖层次和神经走行在层次部位,在直肠固有筋膜和腹下神经输尿管前筋膜之间分离,可以完好地保留腹盆腔自主神经系统,以筋膜层膜为导向,进行筋膜之间分离,以神经为导向,实现精准直肠癌手术,对于提高手术质量,保护器官功能至关重要。     

Transanal single-port laparoscopic total mesorectal excision in the treatment of rectal cancer

Our objective was to report of our first experience with transanal total mesorectal excision (TME) of rectal cancer using single-port equipment, a pure natural orifice transluminal endoscopic surgery (NOTES) procedure, and to discuss the advantages and disadvantages of the technique. A patient with rectal cancer was selected according to preoperative evaluation criteria. Purse-string sutures were placed into the rectum distal to the tumor using the procedure of prolapse and hemorrhoids (PPH) anoscope. A full-thickness incision of the rectal wall was made circumferentially below the purse string and a three-channel cannula was inserted. The artificial orifice was insufflated. The entire mesorectum was dissected upward according to the principles of TME. Pneumoperitoneum was created by opening the rectouterine pouch. The sigmoid colon and its mesentery were dissected, and the inferior mesenteric vessels were ligated and divided. After dissection of a sufficient length of sigmoid colon, the PPH anoscope and the three-channel cannula were removed. The rectum and sigmoid colon were brought out through the anus. The tumor was resected. After removal of the specimens, a stapled end-to-end anastomosis was fashioned between the rectum and the sigmoid colon. Operative time was 300 min. The mesorectum was completely removed with negative distal and circumferential margin. The final pathological stage was pT3N1M0, with one positive lymph node (1/12). The patient recovered uneventfully after surgery. Pure-NOTES performed as transanal single-port laparoscopic TME for rectal cancer appears to be feasible and safe.     

Lymphoscintigraphy in patients with primary rectal cancer: the role of total mesorectal excision for primary rectal cancer--a lymphoscintigraphic study

BACKGROUND AND AIMS: Total mesorectal excision based operations is the gold standard of care in patients with middle and lower rectal cancer, but the extent of resection varies widely. In our view, extended lymphadenectomy is unnecessary with precise total mesorectal excision, i.e., anatomically correct and sharp surgery. PATIENTS AND METHODS: Sixteen patients with primary rectal cancer underwent rectal lymphoscintigraphy 1 day prior continence-preserving anterior resection with total mesorectal excision. The specimens were examined for integrity by postoperative angiography of the superior rectal artery in anteroposterior and lateral views. RESULTS: Twelve patients had only mesorectal lymph nodes, and four had additional extramesorectal iliac lymph nodes. The labeled lymph nodes were identified and removed perioperatively using a gamma probe. Activity was measured again in the preparations outside the situs. Histological examination showed tumor-free lymph nodes only. CONCLUSION: Lymph vessels can be divided anatomically into visceral and somatic, and detection of extramesorectal lymph nodes does not call for lateral lymphadenectomy. Primary rectal cancer confined to the organ metastasizes within the mesorectum and does not invade extraregional lymph nodes. The mesorectum is the major visceral route for caudocranial metastatic spread.     

腹腔镜TME术中直肠前间隙的解剖分离技巧

直肠前间隙的解剖是腹腔镜直肠全系膜切除术（total mesorectal excision,TME）的一个难点。术中若解剖层面不当,容易造成直肠前壁固有筋膜破损或损伤邻近的神经血管束。对于直肠前壁的肿瘤,直肠固有筋膜破裂可能造成环周切缘阳性及局部复发;神经血管束损伤则可能导致术后性功能障碍,特别是在男性患者。掌握直肠前间隙的解剖技巧有利于提高TME手术的手术质量及患者的术后生存质量。     

Denonvilliers’ Fascia Lies Anterior to the Fascia Propria and Rectal Dissection Plane in Total Mesorectal Excision

PURPOSE Opinion is divided whether Denonvilliers fascia lies anterior or posterior to the anatomic fascia propria plane of anterior rectal dissection in total mesorectal excision. This study was designed to evaluate this anatomic relationship by assessing the presence or absence of Denonvilliers fascia on the anterior surface of the extraperitoneal rectum in specimens resected for both nonanterior and anterior rectal cancer in males.METHODS Surgical specimens were collected prospectively from males undergoing total mesorectal excision for mid and low rectal cancer, with a deep dissection of the anterior extraperitoneal rectum to the pelvic floor. Specimens were histopathologically analyzed using best practice methods for rectal cancer. The anterior aspects of the extraperitoneal rectal sections were examined microscopically for the presence or absence of Denonvilliers fascia.RESULTS Thirty rectal specimens were examined. Denonvilliers fascia was present in 12 (40 percent) and absent in 18 specimens (60 percent). Denonvilliers fascia was significantly more frequently present when tumor involved (55 percent) rather than spared the anterior rectal quadrant (10 percent; difference between groups 45 percent; 95 percent confidence interval, 30–60 percent; P = 0.024, Fishers exact test).CONCLUSIONS When tumors were nonanterior, rectal dissection was conducted on fascia propria in the usual anatomic plane, and Denonvilliers fascia was not present on the specimen. It was almost exclusively found in anterior tumors, deliberately taken by a radical extra-anatomic anterior dissection in the extramesorectal dissection plane. Denonvilliers fascia lies anterior to the anatomic fascia propria plane of anterior rectal dissection and is more closely applied to the prostate than the rectum.Presented at the meeting of the Association of Coloproctology of Great Britain and Ireland, Brighton, United Kingdom, July 10 to 12, 2000.Reprints are not available.     

直肠癌直肠系膜中CK20的表达及临床意义

目的:通过对直肠癌直肠系膜中CK20表达的检测,探讨直肠癌区域转移及微转移的规律,为临床直肠癌术式的选择及实施提供依据.方法:应用RT-PCR方法对直肠癌TME术后50例患者的肿瘤组织、直肠系膜及盆筋膜壁层中CK20的表达进行检测,同时分析CK20的表达与病理特征的关系.结果:正常对照组织中无阳性表达,直肠癌组织中CK20高表达(78%),肿瘤平面和直肠系膜近端可表达,直肠系膜远端(20%)和盆筋膜壁层表达(6.38%)程度较低.CK20表达与肿瘤形态、TNM分期、浸润深度有关,而与肿瘤直径、肿瘤分化程度、原发部位无关.结论:直肠癌患者外科治疗时常规行TME是必要的.     

The surgical anatomy of the rectum — a review with particular relevance to the hazards of rectal mobilisation

The major complications of rectal surgery that are wholly or partially avoidable by the use of an anatomically based dissection are haemorrhage from presacral veins, perforation of the rectum, damage to pelvic autonomic nerves and inadequate clearance of a rectal cancer. Important technical points in minimising the incidence of these complications are: (1) posterior dissection in the presacral space; (2) entry to this space by sharp dissection immediately posterior to the superior rectal artery; (3) deliberate incision of the rectosacral fascia; (4) anterior dissection posterior to Denonvilliers fascia in benign disease; (5) removal of the entire mesorectum for low rectal cancer. Other anatomical points not widely appreciated are: 1. The middle rectal artery does not run in the lateral ligaments of the rectum, but below them, on levator ani. It reaches the rectum by penetrating Denonvilliers' fascia. 2. The lateral ligaments may contain an accessory middle rectal artery in 25% of cases. 3. The pelvic autonomic nerves are buried in endopelvic fascia on the pelvic side wall, but come to lie close to the anterior aspect of the rectum at the level of the prostate or upper vagina.     

Relationship between multiple numbers of stapler firings during rectal division and anastomotic leakage after laparoscopic rectal resection

Background We experienced some technical difficulty in dividing the middle and lower rectum through the right-lower quadrant intracorporeally. The aim of this study was to determine whether multiple stapler firings during rectal division are associated with anastomotic leakage after laparoscopic rectal resection. Methods Laparoscopic anterior resection with double-stapling technique anastomosis was performed in 180 consecutive rectal cancer patients. We often used vertical rectal division through a suprapubic site instead of the standard transverse rectal division for laparoscopic total mesorectal excision (LapTME). We attempted to determine whether there was an association between the number of stapler firings and procedures in rectal division. Moreover, we identified risk factors for anastomotic leakage after laparoscopic rectal resection by multivariate analysis. Results Anastomotic leakage occurred in 5% of the subjects of this study. Vertical rectal division through the suprapubic site after Lap TME required fewer staples than transverse division through the right-lower port and a smaller percentage of patients required three or more staples for vertical rectal division than for transverse division (15% vs. 45%, p = 0.03). In the multivariate analysis, TME and the number of staplers used for rectal division were the factors found to be associated with a significantly greater risk of subsequent leakage (odd’s ratio = 5.3; 95% CI 1.2–22.7 and odd’s ratio = 4.6; 95% CI 1.1–19.2). Conclusion TME and multiple stapler firings during distal rectal division were associated with anastomotic leakage after laparoscopic rectal resection. Vertical rectal division through a suprapubic site was a useful method of avoiding multiple stapler firings during laparoscopic TME.     

Definition of total mesorectal excision, including the perineal phase: technical considerations

BACKGROUND: Total mesorectal excision (TME) has contributed to a decline in local recurrence. The operation is difficult because of the complicated anatomy of the pelvis and the narrow spaces in the pelvis. We review the anatomy related to TME and we present our surgical technique. ANATOMY: The pelvis can be divided into a parietal compartment and a visceral compartment. Both compartments are covered by a fascial layer: the parietal and the visceral fascia. A space between these fascial layers can be opened by dividing loose areolar tissue. The pelvic autonomic nerves consist of the sympathetic hypogastric nerve and the parasympathetic sacral splanchnic nerve. At the pelvic sidewall these nerves join in the inferior hypogastric plexus. SURGERY: We present our surgical technique based on careful dissection under direct vision and describe our approach to abdominoperineal resection in the knee-chest position. This position enables en bloc resection of the levator ani muscle with the mesorectum, preventing positive circumferential margins in distal rectal tumor. CONCLUSION: TME is a difficult and challenging operation. Continuous attention to surgical technique and anatomy is important to keep up the high standards of contemporary rectal surgery.     

全直肠系膜切除术切缘血管内皮生长因子检测的临床意义

目的:探讨血管内皮生长因子(VEGF)在直肠癌及其切缘的表达及其临床意义.方法:取实施TME的60例直肠癌患者直肠癌组织(Ⅰ)、直肠系膜远端切缘(Ⅱ)、直肠系膜周围切缘(Ⅲ)、盆筋膜壁层(Ⅳ)病理标本,采用免疫组化SP法对标本进行VEGF检测;并回顾性分析临床病理学资料.结果:直肠癌组织中VEGF高度表达(54/60),肿瘤相对的盆筋膜脏层(直肠系膜周围切缘)中有VEGF存在(9/60),在直肠系膜远端切缘及盆筋膜壁层标本中未见VEGF表达.VEGF在直肠癌组织中的表达有高度特异性.VEGF表达与直肠癌分化程度、Dukes分期及淋巴结转移密切相关(P<0.05或P<0.01).结论:VEGF在直肠癌组织中高度表达,直肠远端系膜切缘及直肠系膜周围切缘不表达或表达为弱阳性.     

Tumorangiogenese beim primären Rektumkarzinom Befunde angiographischer Präparatuntersuchungen

Background: One reason for early metastasis formation and/or the occurrence of a tumor relapse is the formation of tumor vessels respectively the penetration of tumor cells in the rectal vessels. The tumor growth of rectal cancer depends on the generation of new vessels. Hematogenous metastazation is encouraged by an increasing vascularization and has a negative influence on the relapse-free period and the long-time survival of the patients. Method: Tumor-associated changes of the superior rectal artery and the superior rectal vein have been evaluated on 31 operation-specimens by subtraction angiography. Results: The arteria rectalis superior physiologically divides into two branches of the same diameter. Both branches follow the mesorectum in an almost symmetrical fashion caudad, accompanied by the corresponding veins. Conclusion: The DSA images showed various changes in the mesorectal arteries due to tumor-associated neovascularisation. The artery trees in all specimens were complete, confirming anatomically a total mesorectal excision.     

Identification of hiatal ligament for laparoscopic total mesorectal excision

Total mesorectal excision (TME) based operation is now established as a standard procedure for patients with lower or middle third rectal cancer. Laparoscopic surgery has a great advantage in colorectal surgery, with good operative views, as well as benefit to the patients owing to less invasiveness, early recovery and shorter hospitalization. From April 2001 through March 2002, we assessed the laparoscopic TME for eight consecutive patients with rectal cancer in Kobe University Hospital (median age: 65.3). The procedure included sharp mesorectal dissection with high vascular ligation and preservation of autonomic pelvic nerves. During the laparoscopic TME, the hiatal ligament that is the sequence of anococcygeal raphe body can be identified with the traction of the rectum upward, and this fixes the posterior wall of the rectum to the levator hiatus. Resection of the hiatal ligament enables us to isolate the recto-anal canal up to the level of the internal anal sphincter. We conclude that identification of the hiatus ligament is essential to achieve the appropriate laparoscopic TME.     

Vascular Anatomy of the Rectal Stump After Total Mesorectal Excision

Purpose For many years, poor vascularization of the short rectal stump has been considered the main cause of leakage. The purpose of this study was to evaluate the vascularization of the rectal stump after total mesorectal excision. Methods We studied the iliac vascularization on 28 volunteers with healthy rectum to have an anatomic basis. Then, we studied the vascularization of the rectal stumps after total mesorectal excision by using angio computed tomography at seven and three months after operating on 22 patients; we validated this technique by studying the vascularization using angio computed tomography in 18 rectal specimens from cadavers. Results Both in healthy rectums and in rectal stumps after total mesorectal excision, there is good vascularization substained by middle and inferior rectal arteries. The former is more important and frequent as described in previous literature. Conclusions The vascularization of the short rectal stump is generally well represented even after total mesorectal excision. Reprints are not available.     

The pathological assessment of mesorectal excision: implications for further treatment and quality management

BACKGROUND AND AIMS. Most clinical practice guidelines today recommend total mesorectal excision (TME) for carcinoma of the middle and lower rectal thirds and partial mesorectal excision (PME) for the upper rectal third. However, these procedures may not always fulfill the oncological requirements. The pathological examination of resected rectal carcinomas should always include a visual assessment of the mesorectal excision to ensure oncological adequacy and appropriate quality. The clinical practice guideline of the German Cancer Society recommends reporting of the distal extent of mesorectal excision (total or partial without coning) and the excision in an inviolate fascial envelope. PATIENTS AND METHODS. Reporting schemas of assessment and documentation for daily use and for studies are presented. RESULTS. Careful macroscopic evaluation of the resection specimen should be standardized. This may be supplemented by stain marking after postoperative filling the inferior mesenteric or superior rectal artery with ink or methylene blue solution. Photodocumentation is highly desirable. The pathological assessment of adequacy of mesorectal excision should be taken into account in selection for adjuvant radiotherapy. Objective macro- and microscopic assessment of mesorectal excision by pathologists is essential for quality management throughout patient care and in clinical trials.