Lateral pelvic lymph node dissection for advanced lower rectal cancer

[Lymphadenectomy with tumors of the lower gastrointestinal tract]

For advanced adenocarcinomas, which are the most frequent tumours of the lower GI tract, the concept of radical lymphnode dissection is well accepted. The quality of lymphadenectomy for these malignancies has a strong effect on cancer-related survival. Based upon a strict quality control program with outcome evaluated according to internal results, the technique and extent of lymph node dissection have been continuously developed over the last three decades. These are described in detail, including instructive pictures to clarify the surgical steps needed. Apart from multivisceral resection in far advanced cases, which still have a chance of cure if adequate guidelines are followed, two additional steps in the so-called radical surgical treatment of these tumours are prerequisites for cure. The first is complete mobilisation of the intestine involving complete mesocolic excision with complete retention of the visceral fascia and covering potential lymph node metastases and extranodal spread on the intestinal side. The second step is the central tying of the tumor's supplying vessels. Following these rules and with no adjuvant systemic treatment, 5-year survival figures of 80% can be reached, even for UICC stage III disease.

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.

Isolated tumor cell in lateral lymph node has no influences on the prognosis of rectal cancer patients

BACKGROUND AND AIMS

The aim of this study was to determine the incidence of isolated tumor cells (ITC) and micrometastasis in lateral lymph nodes of patients with rectal cancer and its possible correlation with prognosis.

MATERIALS AND METHODS

One hundred seventy-seven rectal cancer patients who underwent curative resection with lateral lymph node dissection were enrolled. Dissected lymph nodes were examined using hematoxylin-eosin staining (HE) and immunohistochemistry (IHC) with anti-keratin antibody (AE1/AE3). States of lymph node metastasis were divisible into three groups: detectable with HE (HE+), detectable with only IHC (HE-/IHC+), and undetectable even with IHC (IHC-). Almost all the HE-/IHC+ group was classified as ITC consisting of a few tumor cells according to the UICC criteria (ITC+). Survival rates were compared among HE+, ITC+, and IHC-.

RESULTS

ITC+ were detected in 24.1% of patients with HE-negative lateral lymph nodes. No significant difference in overall 5-year survival was observed between ITC+ and IHC- patients (76.1 and 82.9%, respectively, p = 0.25). Multivariate analysis showed that perirectal HE+ lymph nodes, but not ITC+ lateral lymph nodes, was an independent prognostic factor.

CONCLUSIONS

ITC in lateral lymph nodes does not contribute to the prognosis of rectal cancer in patients who undergo extended lateral lymph node dissection, unlike HE+ lateral lymph node metastasis.

Total mesorectal excision and pelvic node dissection for rectal cancer: an appraisal

Total mesorectal excision has revolutionized the surgical treatment of rectal cancer since its introduction in the 1980s. The rationale, technique, and outcomes of total mesorectal excision in rectal cancer are explored. Lateral pelvic lymph node dissection is used by the Japanese in selected patients and has remained a controversial approach in the management of rectal cancer. The technique, controversies, and outcomes are summarized.

Morphological characteristics of lateral pelvic lymph nodes in rectal carcinoma

AIM

Macroscopic and imaging indicators for lymph node metastasis have been documented not in lateral pelvic lymph nodes but in mesorectal lymph nodes in patients with rectal carcinoma. We conducted this study to uncover morphological characteristics of lateral pelvic lymph nodes in patients with rectal carcinoma.

MATERIALS AND METHODS

Fifty-eight patients with locally advanced rectal carcinoma who had total mesorectal excision and lateral pelvic lymph node dissection were studied. Total number of lateral pelvic lymph nodes evaluated was 462, with 538 mesorectal lymph nodes being used for comparison. Factors of lymph nodes evaluated were size (long- and short-axes diameters), shape (ovoid and irregular), and heterogeneity of internal structure. Receiver operating characteristic (ROC) curve analysis was used to compare the diagnostic accuracy of each factor.

RESULTS

Lateral pelvic lymph node at non-metastatic status appeared to be longer (4.5 vs 3.5 mm) and thinner (2.2 vs 2.6 mm) than mesorectal lymph nodes. ROC curve analysis, for discriminating non-metastatic and metastatic lateral pelvic lymph nodes, revealed that a short-axis diameter appeared to be the most prominent factor with highest area under curve (0.907) and was more reliable than either long-axis diameter (0.811) or shape (0.527) other than internal structure (1.00). A short-axis diameter was an independent risk factor for metastasis by multivariate analysis with an odds ratio of 1.29 (p < 0.0001, 95% confident interval, 1.22-1.36). The most reliable cut-off value was 4 mm with 96% of sensitivity, 68% of specificity, and 82% of overall accuracy.

CONCLUSION

Lateral pelvic lymph nodes tended to be longer and thinner than mesorectal lymph nodes at non-metastatic status. A short-axis diameter of 4 mm or larger was the prominent indicator of metastasis in lateral pelvic lymph nodes.

Analysis of clinical outcomes and prognostic factors of neoadjuvant chemoradiotherapy combined with surgery: intraperitoneal versus extraperitoneal rectal cancer

Neoadjuvant chemoradiotherapy (CRT) is a widely purposed and performed treatment for rectal cancer. Downstaging effects possibly enhance the rate of curative surgery and may enable sphincter preservation in low-lying tumours. The current study examines the clinical outcomes in patients enrolled in a neoadjuvant CRT-surgery protocol for rectal cancer, distinguishing between intraperitoneal and extraperitoneal cancer. From 1994 to 2003, 58 patients with a primary diagnosis of rectal cancer were enrolled in a single-centre, not randomized study based on 5-week sessions of radiotherapy associated with a 30-day protracted venous 5-FU infusion followed by surgical resection. The study population was divided into two groups according to the localization of the tumour: 18 intraperitoneal and 40 extraperitoneal (EPt). Fifty-eight patients were treated with neoadjuvant CRT and surgery. Overall mortality rate was 25.9%, no deaths were recorded during hospitalization; 10 patients (all EPt) died because of recurrence. Significant differences in disease-free survival and overall survival rates were found between intraperitoneal vs. extraperitoneal tumours (P = 0.006), both intraperitoneal vs. extraperitoneal tumours N(0) (P = 0.04 and P < 0.05) and intraperitoneal vs. extraperitoneal tumours N(+) (P < 0.05). We diagnosed all local recurrence and liver metastasis in extraperitoneal tumours (t = 0.02 and t = 0.04), and only one case of lung metastasis arose from intraperitoneal cancer. Extraperitoneal tumours could be more aggressive than intraperitoneal ones, spreading more precociously, and/or less responsive to the neoadjuvant CRT because of their localization rather than biological differences. Aside from lymph node status, the location of the tumour with respect to the peritoneum border, is also a prognostic factor of survival in rectal cancer treated by neoadjuvant CRT and surgery.

Distribution and patterns of lymph nodes metastases and micrometastases in the mesorectum of rectal cancer

BACKGROUND AND OBJECTIVES

Facts buried in the mesorectum remain to be unveiled. This study investigated the number, size, and detailed distribution of lymph nodes metastases and micrometastases within the mesorectum of rectal cancer.

METHODS

Thirty-one patients who underwent total mesorectal excision (TME) were treated with lymph node revealing solution to retrieve lymph nodes, which were submitted to hematoxylin and eosin (HE) examination and immunohistochemical (IHC) staining.

RESULTS

The mean number of mesorectal nodes per case was 17.7. The mean size of metastatic, micrometastatic, and isolated tumor cells (ITC) harbored nodes was 5.2 mm, 4.5 mm, and 3.3 mm, respectively. Most of the metastatic (92.1%), micrometastatic and ITC-involved nodes (69.2%) were located along the superior rectal artery (SRA). Posterior-wall located tumor might spread along both sides of the mesorectum simultaneously (P = 0.34), while lateral-wall located tumor spread preferably to ipsolateral side versus contralateral side (P = 0.012).

CONCLUSION

Most of the metastases and micrometastases positive lymph nodes were smaller than 5 mm and distributed along the SRA. The patterns of lymph nodes spread were related to the circumferential situation of tumor in the rectal wall. Surgical excision of the rectal cancer should completely remove the whole mesorectum, especially to avoid any damage of the mesorectum on tumor side.

Potential prognostic benefit of lateral pelvic node dissection for rectal cancer located below the peritoneal reflection

OBJECTIVE

To identify the parameters related to the effective selection of patients who could receive prognostic benefit from lateral pelvic node dissection.

BACKGROUND

Accurate preoperative diagnosis of lateral nodal involvement (LNI) remains difficult, and the indications for lateral lymph node dissection have been controversial.

PATIENTS AND METHODS

A total of 244 consecutive patients who underwent potentially curative surgery with lateral dissection for advanced lower rectal cancer (1985-2000) were reviewed. Patients were stratified into groups based on various parameters, and the therapeutic value index for survival benefit was compared among groups. The therapeutic index of lateral dissection was calculated by multiplying the frequency of metastasis to the lateral area and the cancer-related 5-year survival rate of patients with metastasis to the lateral area, irrespective of metastasis to other areas (mesorectal, superior rectal artery [SRA], and inferior mesenteric artery [IMA] areas).

RESULTS

LNI was observed in 41 patients (17%); and 88% of them had nodal involvement in the region along the internal iliac/pudendal artery or in the obturator region ("vulnerable field"). The cancer-related 5-year survival rate among the patients with LNI was 42%; the therapeutic index for lateral dissection was calculated as 7.0 patients, which was much higher than that of lymphadenectomy of the SRA area (1.6 patients) and the IMA area (0.4 patients), and almost comparable to that of lymphadenectomy of the upward mesorectal area (6.9 patients). Although it was possible to select groups at high and low risk for LNI based on several parameters related to tumor aggressiveness, such as tumor differentiation in biopsy specimens, the therapeutic value index was not significantly different between these groups. Unlike these parameters, the diameter of the largest lymph node in the "vulnerable field," which was positively correlated with the rate of LNI but irrelevant to the prognosis, was able to successfully stratify patients by therapeutic index.

CONCLUSIONS

Advanced lower rectal cancer patients having LNI in the lateral pelvic area are likely to receive prognostic benefit from lymphadenectomy. The most efficient means of determining the effectiveness of lateral dissection preoperatively is to estimate the nodal diameter in the "vulnerable" lateral regions by diagnostic imaging.

Surgical treatment of rectal cancer: radical resection

Currently, surgery is the only potentially curative treatment modality for rectal cancer. The major goals of surgery for rectal cancer are to optimize oncologic outcome and maintain anorectal and genitourinary function. This article reviews the surgical management of primary rectal cancer and discusses major surgical considerations in the treatment of this disease.

Can the results of anorectal (abdominoperineal) resection be improved: are circumferential resection margins too often positive?

Carefully executed surgery for rectal cancer has reduced the incidence of local recurrence after restorative resection. Three recent large prospective series have confirmed the perception of a higher positive circumferential resection margin (CRM) rate after abdominoperineal resection. Tumour spread is different for low tumours and the surgical technique of abdominoperineal resection, perhaps better known as anorectal excision, may vary between surgeons. There is a need to redefine the place of anorectal excision and the contribution that can be made by pre-operative chemoradiation and/or extended surgery to reduce local recurrence and increase survival. Defined surgery, validated by histopathological assessment, as applied to TME surgery, would determine whether the perceived higher rates are due to the differences in routes of tumour spread or to surgically related variables. Unnecessary R1 or R2 resections and operative perforation can be minimized by an understanding of the surgical anatomy, the pattern of spread and difference in operative technique between anorectal excision and a low restorative operation. Surgical technique to maximize R0 resection should be based on a detailed understanding of the pelvic fascia and the levator ani and the use of pre-operative imaging to define lines of excision. With the adoption of even lower restorative resection (intersphincteric) there is a need to reassess the method of anorectal excision. This may be achieved by histopathological assessment of CRM positivity and MDT audit to improve results. Clinical trials are essential.

Anatomic basis of sharp pelvic dissection for curative resection of rectal cancer

The optimal goals in the surgical treatment of rectal cancer are curative resection, anal sphincter preservation, and preservation of sexual and voiding functions. The quality of complete resection of rectal cancer and the surrounding mesorectum can determine the prognosis of patients and their quality of life. With the emergence of total mesorectal excision in the field of rectal cancer surgery, anatomical sharp pelvic dissection has been emphasized to achieve these therapeutic goals. In the past, the rates of local recurrence and sexual/voiding dysfunction have been high. However, with sharp pelvic dissection based on the pelvic anatomy, local recurrence has decreased to less than 10%, and the preservation rate of sexual and voiding function is high. Improved surgical techniques have created much interest in the surgical anatomy related to curative rectal cancer surgery, with particular focus on the fascial planes and nerve plexuses and their relationship to the surgical planes of dissection. A complete understanding of rectum anatomy and the adjacent pelvic organs are essential for colorectal surgeons who want optimal oncologic outcomes and safety in the surgical treatment of rectal cancer.

Long-term outcome of per anum intersphincteric rectal dissection with direct coloanal anastomosis for lower rectal cancer

OBJECTIVE

The authors have performed per anum intersphincteric rectal dissection. With direct coloanal anastomosis for cases of lower rectal cancer in which the distal surgical margin is difficult to secure by the double stapling technique. The aim of this study was to evaluate the long-term outcome and to clarify the surgical indications for this operation.

PATIENTS AND METHODS

Between 1993 and 2002, 31 patients underwent per anum intersphincteric rectal dissection with direct coloanal anastomosis. Of these, two patients (one stage 0 and one stage IV) were excluded from the analysis of oncological outcome. The remaining 29 patients formed the basis of this study. The median follow-up was 57 months (range 6-106 months).

RESULTS

Local recurrence and distant metastasis developed in 9 and 3 patients, respectively. Local recurrence rate for pT1 was significantly lower than that for pT2/T3 disease. The local recurrence rate cases with tumours less than 3 cm was significantly lower than that for tumours sized 3 cm or more. The distant metastasis rate for cases with lymph node metastasis was significantly higher than that for cases without lymph node metastasis. There was an association between distant metastasis and TNM or pT stage. The overall survival rates for stage I, II and III were 85%, 80% and 89%, respectively. No significant difference was seen in total Cleveland Clinic incontinence score between per anum intersphincteric rectal dissection with direct coloanal anastomosis and the double stapling technique.

CONCLUSION

The surgical indications of this operation should be limited to patients with T1 rectal cancer or tumours less than 3 cm.

Impact of lateral pelvic lymph node dissection on evacuatory and urinary functions following low anterior resection for advanced rectal carcinoma

BACKGROUND AND AIM

Lateral pelvic lymph node dissection (LPLD) has been reported to be beneficial in terms of survival for locally advanced low rectal carcinoma. However, the impact of LPLD on bowel function has not yet been determined by means of anorectal physiologic investigation.

PATIENTS AND METHODS

Fifty-seven rectal cancer patients who underwent low anterior resection were evaluated with clinical and physiologic parameters. Of these, 15 patients had LPLD. The postoperative bowel and urinary function were evaluated with patients' questionnaire and anorectal manometry before and after the operation.

RESULTS

The proportion of patients who had pouch reconstruction, adjuvant radiation therapy, and autonomic nerve dissection were significantly higher in the LPLD group. The incidence of evacuatory dysfunction was significantly higher (80% vs 45%) postoperatively in the LPLD group. There was no significant difference in anal sphincter pressures, sensory threshold, and neorectal volumes between the groups postoperatively. In terms of urinary function, use of medication for urination was significantly frequent in the LPLD group. Multivariate analysis identified the level of anastomosis as an independent affecting factor for evacuatory dysfunction and LPLD for urinary dysfunction.

CONCLUSION

Although LPLD affected urinary dysfunction, it did not impair postoperative evacuatory function in the early postoperative period.

Is the lateral lymph node compartment relevant?

Lateral pelvic lymphadenectomy is routinely performed in advanced lower rectal cancers by Japanese surgeons, whereas in the western world it has not progressed to a frequently performed technique. Claimed benefit for this extensive surgery is an improved locoregional control; on the other hand, low positive lateral lymph node yields, questionable prognostic significance, and high morbidity (urinary and sexual dysfunction) are main reasons against this procedure. Clinical results published on lateral lymphadenectomy in the literature are conflicting. Due to major improvements in local control and survival of rectal cancer patients mainly based on preoperative radiotherapy and total mesorectal excision (TME), only a few patients may profit from lateral lymph node dissection. This article gives an overview of the current status and the clinical relevance of the lateral lymph node compartment in rectal cancer surgery.

Safety of Laparoscopic Intracorporeal Rectal Transection With Double-Stapling Technique Anastomosis

To assess the feasibility and analyze the short-term outcomes of laparoscopic intracorporeal rectal transection with double-stapling technique anastomosis, a review was performed of a prospective registry of 67 patients who underwent laparoscopic sigmoidectomy and anterior resection with intracorporeal rectal transection and double-stapling technique anastomosis between July 2001 and January 2004. Patients were divided into 3 groups: sigmoid colon/rectosigmoid carcinoma, upper rectal carcinoma, and middle/lower rectal carcinoma. A comparison was made of the short-term outcomes among the groups. The number of cartridges required in bowel transection was significantly increased in patients with middle/lower rectal carcinoma, and significant differences were observed in the length of the first stapler cartridge fired for rectal transection. Furthermore, mean operative time and blood loss were also significantly greater in the middle/lower rectum group; however, complication rates and postoperative course were similar among the 3 groups. No anastomotic leakage was observed. Laparoscopic intracorporeal rectal transection with double-stapling technique anastomosis can be performed safely without increased morbidity or mortality.

A comparison of the complication rates between laparoscopic colectomy and laparoscopic low anterior resection

BACKGROUND

This study compared the short-term outcomes, including the complication rate and minimum surgical invasiveness, between patients with colon and rectal carcinomas, who underwent laparoscopic surgery.

METHODS

A review evaluated 151 patients who underwent laparoscopic colectomy (Lap-colectomy; n = 120) and laparoscopic low anterior resection (Lap-LAR; n = 31) between July 2001 and December 2003. The short-term outcomes were compared between the two groups.

RESULTS

The mean operative time and blood loss were significantly greater in the Lap-LAR group. However, the complication rates and postoperative course between the two approaches were similar, and no anastomotic leakage was observed. There was no significant difference in the serum C-reactive protein level and white blood cell count between the two groups in the early postoperative period.

CONCLUSIONS

Lap-LAR for rectal carcinoma can be performed safely without increased morbidity or mortality, and its short-term benefits are comparable with those conferred by Lap-colectomy.

Anatomic pathology of tumor cell spread through lymph nodes in the mesorectum of rectal cancer

AIM: To investigate the size, distribution, and pattern of metastases and micrometastases of lymph nodes (LNs) within the mesorectum of rectal cancer.

METHODS: All rectal cancer specimens obtained by total mesorectal excision were treated with lymph node revealing solution to retrieve all LNs, which were detected with a combination use of haematoxylin and eosin staining and immunohistochemical (IHC) staining with an antibody against cytokeratin 20.

RESULTS: A total of 548 LNs in 31 specimens were harvested, with 17.7 nodes per case. 153 nodes (27.9%) in 27 patients (87.1%) were found positive by routine pathological examination and IHC staining. Of all the nodes retrieved, nodes <0.5 cm numbered 366 (66.8%) with 91 (59.5%) positive. Among the 27 metastasized cases, there were 15 cases whose tumors were located in the back wall of the rectum, in which 78 nodes were detected positive with 75 nodes along the superior rectal artery. In the other 12 cases with tumors positioned in the lateral wall, 75 nodes were diagnosed positive, with 37 nodes, 8 nodes around the branch of superior rectal artery and middle rectal artery on tumor side, and 9 nodes, 0 nodes on the opposite side, respectively.

CONCLUSION: The majority of tumor positive LNs in the mesorectum are <0.5 cm in diameter. LNs within the mesorectum are distributed mainly along major supplying vessels with around the superior rectal artery most. The pattern of lymphatic spread of rectal cancer has close relationships with tumor location in the rectal wall. Tumors in the posterior wall may spread in both sides of the mesorectum simultaneously, while tumors localized in one lateral wall tend to metastasize preferably to LNs in the mesorectum of tumor side.