Lateral Lymph Node Dissection for Lower Rectal Cancer

The mainstay of surgical therapy for rectal cancer is colectomy (including lesions) with lymph node dissection. The lymphatic spread of rectal cancer can proceed in two directions: medially toward the origin of the inferior mesenteric artery or laterally toward the pelvis aslong the internal iliac artery. To prevent postoperative recurrence, lymph nodes situated along these two axes should be adequately dissected, leaving no residual cancer cells. In Japan, the standard procedure for advanced lower rectal cancer is mesorectal excision and lateral lymph node dissection with autonomic nerve preservation. In Europe and North America, lateral lymph node dissection used to be performed, but it led to increased blood loss, complications, and dysfunction, with no improvement in survival. Lateral lymph node dissection is thus no longer performed. Instead, multidisciplinary therapy combining mesorectal excision with preoperative chemoradiotherapy is now the standard treatment for advanced rectal cancer. Although lateral lymph node dissection decreases the rate of local recurrence similar to preoperative chemoradiotherapy, whether it contributes to improved survival remains unclear. In addition, it is unlikely that prophylactic lateral lymph node dissection is required in all patients with rectal cancer. Definition of the indications for lateral lymph node dissection is thus an important concern.     

Actual standards and controversies in colorectal cancer surgery

In early colorectal cancer, the standard treatment for superficial carcinoma limited to the mucosa is endoscopic polypectomy or local resection. If the carcinoma invades the submucosa, the standard surgical procedure is bowel resection with lymph node dissection. In advanced colon cancer, the ideal extent of bowel resection is defined by removing the blood supply and lymphatics at the level of the origin of the primary feeding arterial vessels. When the primary tumor is equidistant from two feeding vessels, both vessels should be excised at the origin. It is desirable to remove is more than 10 cm of the bowel on either side of the primary tumor. The value of no-touch isolation is controversial. Laparoscopic-assisted colectomy should be limited to clinical trials. For patients with advanced rectal cancer, 4-6 cm clearmargins from the attached mesorectum distal to the tumor are desirable. The ideal distal margin length is 3 cm or greater from the transected mucosal edge to the distal edge of the primary tumor. The inferior mesenteric artery should be excised at its origin. Extended lateral lymph node dissection is indicated for patients with lower rectal cancer invading the muscularis propria or deeper. In stage IV and recurrent cancer, surgical resection is recommended if it appears to offer cure.     

机器人直肠癌根治术

术中自肠系膜下动脉下方切开乙状结肠系膜,游离Toldts间隙,暴露并保护左侧输尿管及生殖血管。切断肠系膜下动脉根部,清扫253组淋巴结。切开乙状结肠侧腹膜,游离乙状结肠下段。提起肠系膜下动脉血管蒂(已切断),沿Toldts层面分离直肠系膜与骶前间隙,环形完整游离直肠系膜,于肿瘤标记处远端约5cm处以直线切割闭合期切断直肠肠管。肠管断端提出体外,距离肿瘤近端约10cm,切断乙状结肠肠管,并包埋吻合器钉座。行乙状结肠-直肠端端吻合(Dixon手术)     

腹腔镜直肠癌低位前切除术

腹腔镜直肠癌低位前切除术。术中首先经中间入路打开乙状结肠系膜内侧浆膜,循Toldt’s间隙向头侧游离至肠系膜下动脉根部,夹闭离断肠系膜下动脉,并清扫253组淋巴结;继续向外侧、尾侧游离左侧Toldt’s间隙,并向下延续至直肠后间隙,分离过程中注意保护左侧输尿管、左侧生殖血管。沿左结肠旁沟打开结肠系膜与侧腹壁的融合筋膜,向上游离左侧结肠至脾曲。向下继续沿直肠后间隙分离,并向两侧拓展;前方在腹膜返折略上水平打开腹膜,在邓氏筋膜前间隙向下游离,从前、后及两侧交替游离并完整切除直肠系膜;双吻合器法切除直肠肿瘤及重建肠道。     

中低位直肠癌侧方淋巴结阳性的危险因素分析

目的探讨影响中低位直肠癌侧方淋巴结阳性的危险因素。 方法回顾性分析2019年1月1日至2020年12月30日两家医院102例中低位直肠癌行腹腔镜根治性切除并进行侧方淋巴结清扫术患者的临床资料,根据侧方淋巴结转移情况将其分为阳性组（n=21例）和阴性组（n=81例）。临床数据采用SPSS 22.0软件进行统计学分析,计数资料以［n（%）］表示,采用χ²或Fisher精确检验;侧方淋巴结阳性的危险因素采用Logistic多因素分析。以P<0.05为差异有统计学意义。 结果102例中低位直肠癌患者侧方淋巴结清扫总数为1347枚,其中阳性淋巴结占比为8.1%;单因素分析结果显示,患者年龄、肿瘤直径、分化程度、肿瘤类型、T分期及浸润肠壁程度与侧方淋巴结阳性的发生均有明显相关性（P<0.05）;Logistic回归分析显示,低分化、浸润型、T_3-4期及浸润肠壁浆膜外肿瘤是中低位直肠癌侧方淋巴结阳性的独立危险因素（P<0.05）。 结论中低位直肠癌患者肿瘤组织低分化、浸润型癌、肿瘤分期T_3-4及浸润肠壁浆膜外可作为判断侧方淋巴结转移的独立危险因素,建议对存在这些危险因素的患者行侧方淋巴结清扫术。     

关于中低位直肠癌侧方淋巴结清扫的争论

直肠癌的侧方淋巴结清扫的范围、指征及疗效,不同国家、不同学派的医生的观点存在一定差异。目前认为侧方清扫主要适用于中低位、病理为低分化或T3~4的直肠癌病人,术前可应用放射性核素显像、腔内超声或PET-CT等评估侧方淋巴结情况。侧方清扫对外科技术要求很高,术中应注意在髂内血管和盆壁及闭孔筋膜之间进行分离,直至暴露闭孔神经,清扫淋巴结总数至少应在10枚以上。目前侧方清扫可以降低肿瘤复发率已得到肯定,但侧方淋巴结清扫已达第3、4站,其必要性国际上仍存在争论。笔者认为侧方淋巴结清扫仍有生命力及存在价值,TME基础上改良清扫或选择性侧方淋巴结清扫。腹腔镜下的TME及侧方清扫等均是直肠癌手术今后若干的方向之一。     

Treatment of lateral node metastasis from lower rectal cancer

Lateral lymphatics of the rectum originate in the area where branches of the inferior hypogastric plexus and the middle rectal vessels from the internal iliac vessels enter the mesorectum below the level of the peritoneal reflection in the pelvis, then reach the bifurcation of iliac vessels along the internal iliac vessels. Among lateral lymph nodes, the middle rectal, obturator, and internal iliac lymph nodes are important from the viewpoint of both the incidence of metastais and treatment effects. Although total mesorectal excision (TME) had become the standard surgical treatment for rectal cancer by the 1990s, this technique does not treat lateral node metastasis. A randomized clinical trial of TME versus D3 lymphadenectomy (JCOG0212) was started in 2003, and the registration of 701 patients with lower rectal cancer was completed in August 2010. The results of this clinical trial are highly anticipated. In Japan, where the rate of local recurrence after surgery is low, patients at high risk of local recurrence such as those with lateral node metastasis, T4 disease, and multiple lymph node metastases in the mesorectum should be selected to receive preoperative chemoradiation. Japanese surgeons who treat rectal cancers are in an advantageous position because they have the additional measure of lateral node dissection along with TME and chemoradiotherapy.     

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??A dispute over lateral lymph node dissection in lower rectal cancer SHI Ying-qiang. Department of Abdominal Surgery, Cancer Hospital,Fudan University??Shanghai 200032, China Abstract Lateral lymph node dissection for lower rectal cancer varies a lot in its extent, indication and effect between surgeons in different countries or background. It is commonly believed that patients with tumor in lower rectal, high grade or T3-4 invasion should be the candidate for lateral lymph node dissection, in whom a radionuclide image, endosonography and PET-CT can be utilized for evaluating the lymph node status preoperatively. Lateral lymph node dissection should be proceeded by a proficient and skill-full surgeon, for whom dissection should be carried on along the space between intra-iliac vessels, pelvic wall and obturator facial plane until the obturator nerve is exposed. The number of lymph nodes dissection for pathological examination should be at least 10. Up to now, the effect of lateral lymph node dissection to decrease the local recurrence rate has been confirmed worldwide, but its necessity is still controversial and debated by large clinical trails. From the author’s view, lateral node dissection for lower rectal cancer is valuable and efficient. Modified or elective lateral node dissection with TME or even in laparoscopy may be a prospective direction in the future for the treatment of patients with lower rectal cancer.     

进展期低位直肠癌新辅助放化疗后侧方淋巴结清扫的选择和意义

侧方淋巴引流是低位直肠癌3个重要的淋巴引流方向之一。沿引流途径清扫淋巴结是直肠癌根治术基本要求,也决定淋巴结清扫范围。但侧方淋巴结是区域淋巴结还是远处淋巴结,一直存在争议。这带来新辅助放化疗和侧方淋巴结清扫、以及新辅助放化疗对侧方淋巴结转移疗效的争议。笔者综合分析国内外研究进展,对直肠癌侧方淋巴结转移规律、影响侧方淋巴结转移复发危险因素以及放化疗前后MRI检查对侧方淋巴结评估等进行深入阐述,并结合临床实践,探讨进展期低位直肠癌新辅助放化疗后侧方淋巴结清扫的选择和意义。     

Prediction of lateral pelvic node involvement in low rectal cancer by conventional computed tomography

BACKGROUND: The clinical significance of lateral pelvic lymphatic spread in rectal cancer remains unknown. The present study aimed to assess the accuracy of preoperative computed tomography (CT) for prediction of lateral node involvement in patients with low rectal cancer and to determine the prognostic significance of extended lateral node dissection. METHODS: A total of 109 patients with primary low rectal cancer were enrolled in this prospective cohort study. The preoperative CT findings were compared with the histopathological results and with follow-up data. RESULTS: CT diagnosed lateral lymph node status with high accuracy (sensitivity 95 per cent, specificity 94 per cent), in marked contrast to mesorectal node status. Of 68 patients who had R0 resection without lateral node dissection, only two developed pelvic wall recurrence during median follow-up of 4.1 years. Metastatic nodes in the lateral pelvic region were significantly larger than those in the mesorectum (P < 0.001). CONCLUSION: CT accurately predicted lateral lymph node status in low rectal cancer, allowing preoperative identification of patients who might benefit from extended lateral node dissection.     

直肠癌系膜淋巴结转移的临床病理学研究

目的探讨直肠癌系膜淋巴结转移的规律。方法 2 6例患者取淋巴结 4 4 3枚 ,应用淋巴结显示液处理全直肠系膜切除的直肠癌标本 ,对切取的淋巴结进行病理检测。结果 2 3例(88 5 % )患者的 1 2 8枚 (2 8 9% )淋巴结发现肿瘤转移 ,淋巴结直径≤ 0 5cm者 76枚 (5 9% )。转移病例中 ,后壁直肠癌 1 4例 ,71枚淋巴结有肿瘤转移 ,6 8枚分布于直肠上动脉旁。侧壁直肠癌 9例 ,5 7枚淋巴结有肿瘤转移 ,其中同侧直肠上动脉分支旁转移 2 9枚 ,对侧 7枚 ,同侧直肠中动脉旁转移4枚、对侧无转移。结论后壁直肠癌转移主要为上行扩散 ,侧壁直肠癌可伴有侧方淋巴结受累 ,并以肿瘤同侧淋巴结转移为主     

溶脂法研究直肠癌在直肠远端系膜内的播散

目的 研究直肠癌在直肠远端系膜内播散的规律.方法 收集直肠癌根治手术标本60例,整体平铺用溶脂法处理后,绘制淋巴结分布图,逐个定位、计数淋巴结及癌转移结节,显微镜下观察其转移规律.结果 直肠癌在直肠远端系膜的播散方式主要为淋巴结转移和癌转移结节形成,远端系膜总播散率为13%（8/60）,淋巴结播散率为10%（6/60）,癌结节播散率为7%（4/60）,播散最远距离为4.5 cm.肿瘤大体类型、组织学类型和浸润深度是影响直肠癌远端系膜淋巴结播散的因素.肿瘤部位及Dukes分期是影响直肠癌远端系膜癌转移结节播散的因素.结论 利用溶脂法能全面客观地观察直肠远端系膜内癌组织的播散规律.直肠癌手术远端系膜切除距肿瘤下缘不应少于4.5 cm或行全系膜切除.     

Does perifascial rectal excision (i.e. TME) when combined with the autonomic nerve‐sparing technique interfere with operative radicality?

Objective The lymphatic drainage from the rectum was studied to evaluate if the autonomic nerve sparing dissection may interfere with the operative radicality and might result in metastatic lymph nodes being overlooked and left in situ. Patients and methods 50 consecutive patients had an extended extrafascial rectal excision resection for cancer. In 19 of the 50 patients activated carbon particles (CH40) were injected preoperatively into the rectum. The autonomic nerves with surrounding connective tissue were serially dissected from the resected specimen , carefully sliced at 5‐mm intervals and collected for histological study. Lymph nodes along the axial and lateral drainage routes were examined, and the inclusion of CH40 in the nodes was microscopically studied according to the site of CH40 injection. Results Lymph nodes within the connective tissue along the dissected autonomic nerves were demonstrated in 47 of the 50 cases. Two of 50 cases had positive nodes along preaortic plexus or pelvic plexus, and a case with nodal involvement along the pelvic plexus had poor prognosis in spite of nerve excision. CH40 when injected into the rectum above the peritoneal reflection was demonstrated in the vast majority of the axial nodes, while in only one lymph node along the preaortic plexus when injected in the rectum above the peritoneal reflection. On the other hand when injected in the rectum below the peritoneal reflection, CH40 was demonstrated both in axial and lateral nodes as well as in lymph nodes along bilateral pelvic plexuses, right hypogastric nerve, superior hypogastric plexus, preaortic plexus and mesenteric plexus as well. Conclusions When located above the peritoneal reflection a rectal carcinoma will spread preferentially along the upper axial route, while a carcinoma located below the peritoneal reflection will also spread laterally and along the autonomic nerves. It was inferred that lymphatic flow along the autonomic nerves came up from the rectum below the peritoneal reflection mainly through a so‐called lateral ligament but its clinical significance was negligible. Therefore doing TME with autonomic nerve preservation does not imply a less radical surgery from the point of lymphatic spread.     

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??Management of the lateral lymph node dissection in rectal cancer LAN Ping??CHEN Yu-feng??WU Xian-rui. Department of Colorectal Surgery??the Sixth Affiliated Hospital??Sun Yat-sen University??Guangzhou 510655??China
Corresponding author: LAN Ping??E-mail: lanping@mail.sysu.edu.cn
Abstract Lateral lymph node dissection in rectal cancer, which is difficult in practice and has a high risk of postoperative urinal and sexual dysfunction??is not routinely performed in China. Neoadjuvant therapy??radiological evaluation and surgical method have great impact on the outcome of lateral lymph node dissection. It is better to beware of the management of lateral lymph node dissection??while planning the surgical intervention for the patients with rectal cancer. For patients with stage II and III local advanced rectal cancer, which locates below the peritoneal reflection, the lateral lymph node dissection is suggested to perform under the following criteria. Firstly, the surgical plan should be made based on the preoperative MR examination. For patients with resectable tumor, it’s not necessary to perform the lateral lymph node dissection when no lateral lymph node with short axis larger than 5 mm is found in MR examination. The dissection should be performed when lateral lymph node with short axis larger than 5 mm is indicated. For patients with unresectable tumor, such as pelvic invasion, it’s better to provide neoadjuvant therapy first, and then the lateral lymph node should be evaluated again. If lateral lymph node with short axis larger than 5 mm is still detected, the lateral lymph node dissection should be performed. But it’s unnecessary to do the dissection while no lateral lymph node with short axis larger than 5 mm is found. Secondly, as postoperative urinary dysfunction and sexual dysfunction are often observed, which might result from the injury to the pelvic plexuses in the surgery, unilateral lymph node dissection is suggested. Only when enlarged lymph nodes are found in both sides, bilateral dissection is performed. As well, pelvic automatic nerve should be preserved carefully during the surgery. Thirdly, for surgeons who are skillful in robotic and laparoscopy surgery, minimally invasive surgery could be used.     

腹腔镜直肠癌根治术侧方淋巴结清扫术

对腹膜反折以下cT3或N＋的直肠癌行侧方淋巴结清扫术可减少局部复发率及提高生存率。该术式采用五孔法完成,按日本学组提出的三间隙原则进行清扫：①分离保护输尿管及下腹神经,清扫下腹神经丛及下腹神经与髂总动脉、髂内动脉之间的第二间隙淋巴结;②清扫髂内外动脉间及闭孔内的第三间隙淋巴脂肪组织;③切除髂内血管及盆丛神经。应视肿瘤部位、浸润深度以及侧方淋巴结肿大情况,选择性行单或双侧清扫。腹腔镜下完成侧方淋巴结清扫具有视野好、狭小间隙操作方便、出血少等优势,是一种安全可行的手术方式。     

中低位直肠癌逆向转移的研究

目的探讨中低位直肠癌实施直肠全系膜切除术（TME）时，肿瘤平面以下系膜与肠管切除的范围。方法将60例经标准TME切除的中低位直肠癌肿瘤标本，以5mm间距由肿瘤下缘横断面连续取材至下切缘．大组织切片常规苏木精-伊红染色观察转移灶，并进行统计分析。结果有15例（25．0％）患者出现肠系膜逆向转移，转移距离0．5～4．0（2．47±1．06）cm；肠系膜逆向转移与Dukes分期（P〈0．01）、肠旁淋巴结转移（P〈0．01）和组织分化程度（P〈0．05）相关。11例（18．3％）患者为肠壁内逆向浸润，转移距离0．5～4．0（1．64±1．16）cm。肠壁内逆向浸润与组织分化程度相关（P〈0．05）。结论中低位直肠癌实施保肛手术时，宜切除4．0cm远端系膜和2．5cm肠管；肿瘤病理分期晚、有肠旁淋巴结转移和分化程度不良时，最好切除5cm远端系膜和肠管。     

侧方淋巴结清除在直肠癌根治术中的临床意义

目的：探讨侧方淋巴清除在直肠癌根治术中的临床意义。方法：对36例低位进展期直肠癌患者行根治术，清除上方3组淋巴结的同时行侧方淋巴结清除，对分组淋巴结的转移情况进行评价。结果：36例中有19例有侧方淋巴结转移，其中侧方淋巴转移5例，占阳性淋巴结病例的26．3％（5／19），占全部病例的13．9％（5／36），结论：为保证根治手术的彻底性，减少肿瘤复发，对腹膜返折部以下的进展期直肠癌除上方淋巴结必须清除达第3站外，有必要同时进行侧方淋巴清除。     

Radical lymphadenectomy for rectal cancer facilitated by a carbon particle infusion lymphangiography

For the intraoperative visualization of the para-aortic nodes and those around the iliac vessels, a fine carbon particle solution was infused into the bilateral pedal lymphatic vessels of 12 patients with rectal carcinoma. A low anterior resection with radical lymph node dissection was then performed while preserving pelvic autonomic nerves. Of 444 lymph nodes removed from the iliac arterial region, 430 were stained with carbon black (96.8%), even though the black staining was not perfect in the nodes of the inferior mesenteric arterial region. All of the lateral black stained nodes were clearly visible and hence could be easily excised. The average number of dissected nodes in one patient was 43.8 in this dissection with carbon particle infusion, which was larger than those of conventional lymph node dissection. We then examined the length of time that a postoperative indwelling bladder catheter was needed as an indication for autonomic nerve damage, and it was ascertained that less damage occurred in this operation compared to other types of dissections, such as conventional or extended lymph node dissection.     

腹腔镜直肠癌前切除术

基于COLOR II等研究结果,腹腔镜直肠癌手术的地位得以逐步确立。手术切除是直肠癌最重要的治疗方法,对于上段直肠癌,前切除术是标准术式;对于中下段直肠癌,需遵循全直肠系膜切除(TME)的原则,选择低位前切除术或者腹会阴联合切除术。R0切除是手术治疗的核心要素,这包括两层含义:其一是淋巴结清扫范围需要达到D2水平,其二是标本的远、近端切缘以及环周切缘均需为阴性。准确地解剖出肠系膜下动脉、左结肠动脉以及直肠上动脉,是保证淋巴清扫范围的基础,循"神圣平面"解剖分离直肠系膜是环周切缘阴性和标本完整的保证。     

合理把握直肠癌侧方淋巴结清扫适应证

直肠癌侧方淋巴结清扫手术难度高,术后排尿和性功能障碍等并发症发生率较高,在我国尚未常规开展。术前新辅助治疗、影像学评估和术式选择等均对侧方淋巴结清扫的效果具有重要影响。为直肠癌病人制定手术方案时,应合理把握侧方淋巴结清扫的适应证。对于腹膜返折以下的局部进展期（Ⅱ～Ⅲ期）直肠癌病人实施侧方淋巴结清扫可遵循以下原则：（1）术前应结合MRI检查进行综合判断。对于可根治性切除者,如术前检查提示侧方淋巴结短径≥5 mm,建议进行清扫,否则可不必进行清扫;而对于无法根治性切除者（如盆壁侵犯等）,建议先行新辅助放化疗,治疗后如仍有侧方淋巴结短径≥5 mm者,须进行清扫,否则可不必进行清扫。（2）由于侧方淋巴结清扫易损伤盆腔神经丛,导致术后排尿和性功能障碍,一般建议对淋巴结肿大的一侧进行清扫,仅两侧均出现侧方淋巴结肿大时才考虑进行双侧清扫,清扫过程应注意保留盆腔自主神经。（3）对于有腹腔镜和机器人手术操作经验的医生,可采用微创技术。