Selective lateral lymph node dissection after neoadjuvant chemoradiotherapy in rectal cancer

BACKGROUND Lateral lymph node metastasis is one of the leading causes of local recurrence in patients with advanced mid or low rectal cancer.Neoadjuvant chemoradiotherapy(NCRT)can effectively reduce the postoperative recurrence rate;thus,NCRT with total mesorectal excision(TME)is the most widely accepted standard of care for rectal cancer.The addition of lateral lymph node dissection(LLND)after NCRT remains a controversial topic.AIM To investigate the surgical outcomes of TME plus LLND,and the possible risk factors for lateral lymph node metastasis after NCRT.METHODS This retrospective study reviewed 89 consecutive patients with clinical stage II-III mid or low rectal cancer who underwent TME and LLND from June 2016 to October 2018.In the NCRT group,TME plus LLND was performed in patients with short axis(SA)of the lateral lymph node greater than 5 mm.In the non-NCRT group,TME plus LLND was performed in patients with SA of the lateral lymph node greater than 10 mm.Data regarding patient demographics,clinical workup,surgical procedure,complications,and outcomes were collected.Multivariate logistic regression analysis was performed to evaluate the possible risk factors for lateral lymph node metastasis in NCRT patients.RESULTS LLN metastasis was pathologically confirmed in 35 patients(39.3%):26(41.3%)in the NCRT group and 9(34.6%)in the non-NCRT group.The most common site of metastasis was around the obturator nerve(21/35)followed by the internal iliac artery region(12/35).In the NCRT patients,46%of patients with SA of LLN greater than 7 mm were positive.The postoperative 30-d mortality rate was 0%.Two(2.2%)patients suffered from lateral local recurrence in the 2-year follow up.Multivariate analysis showed that cT4 stage(odds ratio[OR]=5.124,95%confidence interval[CI]:1.419-18.508;P=0.013),poor differentiation type(OR=4.014,95%CI:1.038-15.520;P=0.044),and SA≥7 mm(OR=7.539,95%CI:1.487-38.214;P=0.015)were statistically significant risk factors associated with LLN metastasis.CONCLUSION NCRT is not sufficient as a stand-alone therapy to eradicate LLN metastasis in lower rectal cancer patients and surgeons should consider performing selective LLND in patients with greater LLN SA diameter,poorer histological differentiation,or advanced T stage.Selective LLND for NCRT patients can have a favorable oncological outcome.

Laparoscopic lateral lymph node dissection in two fascial spaces for locally advanced lower rectal cancer

BACKGROUND The procedure for lateral lymph node(LLN)dissection(LLND)is complicated and can result in complications.We developed a technique for laparoscopic LLND based on two fascial spaces to simplify the procedure.AIM To clarify the anatomical basis of laparoscopic LLND in two fascial spaces and to evaluate its efficacy and safety in treating locally advanced low rectal cancer(LALRC).METHODS Cadaveric dissection was performed on 24 pelvises,and the fascial composition related to LLND was observed and described.Three dimensional-laparoscopic total mesorectal excision with LLND was performed in 20 patients with LALRC,and their clinical data were analyzed.RESULTS The cadaver study showed that the fascia propria of the rectum,urogenital fascia,vesicohypogastric fascia and parietal fascia lie side by side in a medial-lateral direction constituting the dissection plane for curative rectal cancer surgery,and the last three fasciae formed two spaces(Latzko's pararectal space and paravesical space)which were the surgical area for LLND.Laparoscopic LLND in two fascial spaces was performed successfully in all 20 patients.The median operating time,blood loss and postoperative hospitalization were 178(152-243)min,55(25-150)mL and 10(7-20)d,respectively.The median number of harvested LLNs was 8.6(6-12),and pathologically positive LLN metastasis was confirmed in 7(35.0%)cases.Postoperative complications included lower limb pain in 1 case and lymph leakage in 1 case.CONCLUSION Our preliminary surgical experience suggests that laparoscopic LLND based on fascial spaces is a feasible,effective and safe procedure for treating LALRC.

T1 rectal mucinous adenocarcinoma with bilateral enlarged lateral lymph nodes and unilateral metastasis:A case report

BACKGROUND There are a few cases of lateral lymph node(LLN)metastasis(LLNM)of T1 rectal cancer.Moreover,LLNM is easily missed,especially in patients with early-stage rectal cancer.To our knowledge,the possibility of bilateral LLNM before surgery has not been reported in previous studies.CASE SUMMARY A 36-year-old woman underwent endoscopic submucosal dissection at a local hospital owing to a clinical diagnosis of a rectal polyp.The pathology report showed a diagnosis of T1 rectal mucinous adenocarcinoma.She was considered to have bilateral LLNM after the examination at our hospital.Laparoscopic total mesorectal excision plus bilateral LLN dissection was performed and the pathological outcomes indicated unilateral LLNM.The patient received longcourse adjuvant chemoradiotherapy with no recurrence or metastasis observed during the 1-year follow-up period.CONCLUSION T1 rectal cancer could lead to LLNM and possibly,bilateral LLNM.Therefore,adequate clinical evaluation is essential for these patients.

Lateral pelvic lymph nodes for rectal cancer:A review of diagnosis and management

The current status and future prospects for diagnosis and treatment of lateral pelvic lymph node(LPLN)metastasis of rectal cancer are described in this review.Magnetic resonance imaging(MRI)is recommended for the diagnosis of LPLN metastasis.A LPLN-positive status on MRI is a strong risk factor for metastasis,and evaluation by MRI is important for deciding treatment strategy.LPLN dissection(LPLD)has an advantage of reducing recurrence in the lateral pelvis but also has a disadvantage of complications;therefore,LPLD may not be appropriate for cases that are less likely to have LPLN metastasis.Radiation therapy(RT)and chemoradiation therapy(CRT)have limited effects in cases with suspected LPLN metastasis,but a combination of preoperative CRT and LPLD may improve the treatment outcome.Thus,RT and CRT plus selective LPLD may be a rational strategy to omit unnecessary LPLD and produce a favorable treatment outcome.

Management of synchronous lateral pelvic nodal metastasis in rectal cancer in the era of neoadjuvant chemoradiation: A systemic review

BACKGROUND Lateral pelvic lymph node(LLN)metastasis(LLNM)occur in up to 28%of patients with low rectal tumours.While prophylactic lateral pelvic lymph node dissection(LLND)has been abandoned by most western institutions in the era of neoadjuvant chemoradiation therapy(CRT),the role of selective LLND in patients with enlarged LLN on pre-CRT imaging remains unclear.Some studies have shown improved survival and recurrence outcomes when LLNs show"response"to CRT.However,no management algorithm exists to differentiate treatment for"responders"vs"non-responders".AIM To determine if selective LLND in patients with enlarged LLNs results in improved survival and recurrence outcomes.METHODS A systemic search of Pub Med and Embase databases for studies reporting on patients with synchronous radiologically suspicious LLNM(s-LLNM)in rectal cancer receiving preoperative-CRT was performed.RESULTS Fifteen retrospective,single-centre studies were included.793 patients with sLLNM were evaluated:456 underwent TME while 337 underwent TME with7,LLND post-CRT.In the TME group,local recurrence(LR)rates range from 12.5%to 36%.Five-year disease free survival(DFS)was 42%to 75%.In the TME with LLND group,LR rates were 0%to 6%.Five years DFS was 41.2%to 100%.Radiological response was seen in 58%.Pathologically positive LLN was found in up to 94%of non-responders vs 0%to 20%in responders.Young age,low tumour location and radiological non-response were associated with final positive LLNM and lowered DFS.CONCLUSION LLND is associated with local control in patients with s-LLNM.It can be performed in radiological non-responders given a large majority represent true LLNM.Its role in radiological responders should be considered in selected high risk patients.

New classification system for radical rectal cancer surgery based on membrane anatomy

BACKGROUND Total mesorectal excision along the“holy plane”is the only radical surgery for rectal cancer,regardless of tumor size,localization or even tumor stage.However,according to the concept of membrane anatomy,multiple fascial spaces around the rectum could be used as the surgical plane to achieve radical resection.AIM To propose a new membrane anatomical and staging-oriented classification system for tailoring the radicality during rectal cancer surgery.METHODS A three-dimensional template of the member anatomy of the pelvis was established,and the existing anatomical nomenclatures were clarified by cadaveric dissection study and laparoscopic surgical observation.Then,we suggested a new and simple classification system for rectal cancer surgery.For simplification,the classification was based only on the lateral extent of resection.RESULTS The fascia propria of the rectum,urogenital fascia,vesicohypogastric fascia and parietal fascia lie side by side around the rectum and form three spaces(medial,middle and lateral),and blood vessels and nerves are precisely positioned in the fascia or space.Three types of radical surgery for rectal cancer are described,as are a few subtypes that consider nerve preservation.The surgical planes of the proposed radical surgeries(types A,B and C)correspond exactly to the medial,middle,and lateral spaces,respectively.CONCLUSION Three types of radical surgery can be precisely defined based on membrane anatomy,including nerve-sparing procedures.Our classification system may offer an optimal tool for tailoring rectal cancer surgery.