Comparison of laparoscopic lateral lymph node dissection for rectal cancer with and without routine resection of the visceral branches of internal iliac artery.

PURPOSE: This study aimed to explore the safety and feasibility of the modified lateral lymph node dissection (LLND) with routine resection of the visceral branches of internal iliac vessels (IIVs) for mid-low-lying rectal cancer. MATERIALS AND METHOD: Consecutive patients undergoing LLND for rectal cancer were divided into the routine visceral branches of the IIVs resection group (RVR group) and the NRVR group (without routine resection). The main outcomes were postoperative complications and the number of lateral lymph nodes harvested. RESULTS: From 2012 to 2021, a total of 75 and 57 patients were included in the RVR and NRVR group, respectively. The operative time was reduced in the RVR group (p = 0.020). No significant difference was observed between the two groups for the incidence of total, major, or minor postoperative complications. Pathologically confirmed LLNM were 24 (32%) patients in the RVR group and 12 (21.1%) in the NRVR group (p = 0.162). The number of lateral lymph nodes harvested had no significant difference between two groups (11 vs. 12, p = 0.329). CONCLUSION: LLND with routine resection of visceral branches of IIVs is safe and feasible, which brings no major complication or long-term urinary disorder.

Robotic versus laparoscopic pelvic lateral lymph node dissection in locally advanced rectal cancer: a systemic review and meta-analysis.

BACKGROUND: There are few available studies that compare the feasibility, efficacy, and safety of robotic pelvic lateral lymph node dissection compared to laparoscopic pelvic lateral lymph node dissection (LPLND) in advanced rectal cancer. This meta-analysis aims to compare perioperative outcomes between robotic and LPLND. METHODS: We performed a systemic literature review of PubMed, Embase, and Web of Science databases. Perioperative parameters were extracted and pooled for analysis. This meta-analysis provided an analysis of heterogeneity and prediction intervals. RESULTS: Five studies were included: 567 patients divided between 266 robotic and 301 LPLND. Overall operation time was longer in the robotic group than laparoscopic group (difference in means = 67.11, 95% CI [30.80, 103.42], p < 0.001) but the difference in the pelvic lateral lymph dissection time was not statistically significant (difference in means = - 1.212, 95% CI [ - 11.594, 9.171], p = 0.819). There were fewer overall complications in the robotic than in the laparoscopic group (OR = 1.589, 95% CI [1.009, 2.503], p = 0.046), especially with respect to urinary retention (OR = 2.23, 95% CI [1.277, 3.894], p = 0.005). More pelvic lateral lymph nodes were harvested by robotic surgery than by laparoscopy (differences in means = - 1.992, 95% CI [ - 2.421, 1.563], p < 0.001). CONCLUSIONS: In this meta-analysis, robotic pelvic lateral lymph node dissection was associated with more pelvic lateral lymph nodes harvested and lower overall complications, especially urinary retention when compared to LPLND. Further studies are needed to reinforce these findings.

Meta-analysis of the efficacy and safety of robot-assisted comparative laparoscopic surgery in lateral lymph node dissection for rectal cancer.

INTRODUCTION: A meta-analysis was conducted on the perioperative and oncological outcomes of robot-assisted and laparoscopic lateral lymph node dissection in rectal cancer. There are few articles and reports on this topic, and a lack of high-quality research results in unreliable research conclusions. This study includes prospective and retrospective studies to obtain more reliable findings. MATERIALS AND METHODS: Databases were searched, including PubMed, EMBASE, Cochrane, and Web of Science. The search was conducted from the time of database construction to March 2024. The quality of the literature was evaluated using the NOS scoring system. Meta-analysis was performed using R language software. Statistical heterogeneity was assessed using the I2 statistic, and sensitivity analysis was performed. RESULTS: Six relevant literatures that met the criteria were finally included, and 652 patients were included, including 316 (48.5%) in the robot-assisted lateral lymph node dissection for rectal cancer group (RLLND) and 336 (51.5%) in the laparoscopic lateral lymph node dissection for rectal cancer group (LLLND). Analysis of the results showed that compared with the laparoscopic group, the robotic group had less mean intraoperative blood loss (MD = - 22, 95% CI - 40.03 to - 3.97, P < 0.05), longer operative time (MD = 51.57, 95%CI 7.69 to 95.45, P < 0.05), and a shorter mean hospital stay (MD = - 1.25, 95%CI - 2.46 to - 0.05, P < 0.05), a low rate of urinary complications (OR 0.39, 95%CI 0.23 to 0.64, P < 0.01), a low overall rate of postoperative complications (OR 0.6, 95%CI 0.42 to 0.87, P < 0.01), and a high number of lateral lymph node dissection (MD = 1.18, 95% CI 0.14 to 2.23, P < 0.05), and there was no statistically significant difference between the two groups in terms of postoperative anastomotic leakage, postoperative intestinal obstruction, and total number of lymph nodes obtained (P > 0.05). CONCLUSION: Compared with laparoscopy, robotic lateral lymph node dissection for rectal cancer reduces intraoperative blood loss, shortens the average length of hospital stay, reduces urologic complications, decreases overall postoperative complications, and collects more lateral lymph nodes. However, the surgical time is prolonged.

Laparoscopic extraperitoneal approach for lateral lymph node dissection for patients with metachronous lateral pelvic lymph node metastases following surgery for rectal cancer: a case series and short-term outcomes.

BACKGROUND: There have been few reports of a totally extraperitoneal approach for laparoscopic lateral lymph node dissection (LLND) for patients with metachronous lateral pelvic lymph node metastases following surgery for rectal cancer. Therefore, this study reports the short-term outcomes of LLND via an extraperitoneal approach. METHODS: A total of 10 patients underwent LLND through a laparoscopic extraperitoneal approach in our hospital since October 2018. Patients with suspected resectable lateral lymph node recurrence after surgery for rectal cancer on computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography CT (PET-CT) were selected for this procedure. RESULTS: Nine of the 10 cases were completed using this procedure, but one case was converted to an intraperitoneal approach. The median operative time was 231 min, and the median estimated blood loss was 10 ml. There was one case of wound infection, but no other postoperative complications were seen. In one patient, no metastases were found in the retrieved lymph nodes. CONCLUSION: The short-term outcomes of LLND through a laparoscopic extraperitoneal approach were acceptable. Because this procedure can be performed without violating the peritoneum, it is less invasive than the conventional intraperitoneal approach and is useful for metachronous lateral pelvic lymph node metastases.

Comparison of the short-term surgical outcomes of lateral lymph node dissection for low rectal cancer using a robotic-assisted transabdominal approach alone or supported by a transanal approach.

BACKGROUND: Lateral lymph node metastases are a major cause of local recurrence after surgery for advanced low rectal cancer. Lateral lymph node dissection (LLND) may reduce the risk of local recurrence in patients with suspected lateral lymph node metastasis. Recent reports have shown that robotic-assisted LLND can help to reduce the postoperative complication rate, such as urinary disturbance. Furthermore, with the advent of transanal total mesorectal excision, a novel LLND procedure that combines a transabdominal approach with a transanal approach has been reported. This study aimed to clarify the safety and feasibility of robotic-assisted LLND supported by a transanal approach for advanced low rectal cancer. METHODS: Thirty-nine patients diagnosed to have low rectal cancer between June 2019 and May 2023 were retrospectively enrolled and divided according to whether they underwent LLND via a robotic-assisted transabdominal approach alone (transabdominal group, n = 19) or in combination with a transanal approach (2team group, n = 20). The patient characteristics and short-term surgical outcomes were compared between the two groups. RESULTS: The total operation time was significantly shorter in the 2team group than in the transabdominal group (366 min vs. 513 min, P < 0.001), as was the time taken to perform unilateral LLND (64 min vs. 114 min, P < 0.001). Furthermore, there was significantly less intraoperative bleeding in the 2team group (30 mL vs. 80 mL, P = 0.004). There was no significant between-group difference in postoperative complications. The incidence of postoperative urinary disturbance was satisfactory at 5% in both groups. CONCLUSIONS: The operation time for LLND performed by a robotic-assisted transabdominal approach was shortened when supported by a transanal approach. The frequency of postoperative urinary disturbance was low in both groups. Therefore, robotic-assisted abdominal LLND supported by a transanal approach can be considered a promising treatment option for advanced low rectal cancer.

Significance of lateral lymph node dissection in squamous cell carcinoma of the anal canal: a retrospective cohort study.

PURPOSE: The JCOG (Japan Clinical Oncology Group) 0212 study did not confirm the noninferiority of mesorectal excision (ME) alone to ME with LLND for rectal or anal adenocarcinomas. Furthermore, the significance of LLND for SCCs remains unknown. We evaluated the significance of lateral lymph node dissection (LLND) of squamous cell carcinoma (SCC) of the anal canal. METHODS: This retrospective cohort study was conducted in 435 patients with SCCs among 1,781 patients with anal canal tumors. In 40 patients who underwent LLND, the 5-year relapse-free survival (5y-RFS) and 5-year overall survival (5y-OS) were compared between groups with positive and negative histopathological findings. In 71 patients with negative lateral lymph node metastasis in the preoperative diagnosis, the 5y-RFS, 5y-OS, and 5-year local recurrence-free survival were compared between patients who did and did not undergo LLND. RESULTS: The clinical and pathological T stages predicted pathological lateral pelvic lymph node metastasis. There was no statistically significant difference in 5y-RFS and 5y-OS between patients who did and did not undergo LLND. Among patients who underwent LLND, 5y-RFS in those with positive histopathological findings (15.0%) was worse than that in those without (59.2%) (p = 0.002). CONCLUSIONS: In patients who underwent LLND, 5y-RFS in those with positive histopathological findings than in those without LLND did not contribute to prognosis.

Learning process analysis of robotic lateral pelvic lymph node dissection for local advanced rectal cancer: the CUSUM curve of 78 consecutive patients.

PURPOSE: Robotic lateral lymph node dissection (LLND) has been described as a safe and feasible procedure for local advanced rectal cancer. The aim of this study was to evaluate the learning curve for robotic-assisted LLND. METHODS: We collected data on 78 consecutive patients who underwent robotic-LLND at our hospital. The learning curve was analyzed using the cumulative sum (CUSUM) method to assess changes in the unilateral LLND operative times across the case sequence. RESULTS: Among the 78 patients, 52 underwent bilateral LLND and 26 underwent unilateral LLND. A total of 130 consecutive data were recorded. We arranged unilateral robotic-LLND operative times and calculated cumulative sum values, allowing the differentiation of three phases: phase I (learning period, cases 1-51); phase II (proficiency period, cases 52-83); and phase III (mastery period, cases 84-130). As the learning curve accumulated, the operation time and estimated blood loss of unilateral robotic-LLND decreased significantly with each phase (P < 0.05). By 12 months after surgery, the International Prostatic Symptom Score of patients at phase III was significantly lower than at phase I (P < 0.05). CONCLUSION: The CUSUM curve shows three phases in the learning of robotic-LLND. The estimated learning curve for robotic-assisted rectal-LLND is achieved after 51 cases.

The use of indocyanine green for lateral lymph node dissection in rectal cancer-preliminary data from an emerging procedure: a systematic review of the literature.

INTRODUCTION: Lateral lymph node dissection (LLND) for rectal cancer is still not a widely established technique owing to the existing controversy between Eastern and Western countries and the lack of well-designed studies. The risk of complications and the paucity of long-term oncological results are significant drawbacks for further applying this technique. The use of indocyanine green (ICG) near-infrared (NIR) fluorescence for LLND appears as a promising technique for enhancing postoperative and oncological outcomes. This review aims to evaluate the emerging role of ICG during LLND and present the benefits of its application. MATERIALS AND METHODS: Systematic electronic research was conducted in PubMed and Google Scholar using a combination of medical subject headings (MeSH). Studies presenting the use of ICG during LLND, especially in terms of harvested lymph nodes, were included and reviewed. Studies comparing LLND with ICG (LLND + ICG) or without ICG (LLND-alone) were further analyzed for the number of lymph nodes and postoperative outcomes. RESULTS: In total, 13 studies were found eligible and analyzed for different parameters. LLND + ICG is associated with significantly increased number of harvested lateral lymph nodes (p < 0.05), minor blood loss, decreased operative time, and probably decreased urinary retention postoperatively compared with LLND-alone. CONCLUSIONS: The use of ICG fluorescence during LLND is a safe and feasible technique for balancing postoperative outcomes and the number of harvested lymph nodes. Well-designed studies with long-term results are required to elucidate the oncological benefits and establish this promising technique.

Mesorectal excision with or without lateral lymph node dissection for elderly patients with mid-low rectal cancer: safety and feasibility analysis.

OBJECTIVE: The perioperative safety and survival benefits of lateral lymph node dissection in elderly patients have been less reported. This study aimed to compare short-term and survival outcomes of total mesorectal excision and total mesorectal excision + lateral lymph node dissection in elderly patients. METHODS: A total of 444 elderly patients (≥65 years) with middle-low rectal cancer were enrolled in three institutions and divided into the total mesorectal excision + lateral lymph node dissection group (n = 110) and the total mesorectal excision group (n = 334). Eighty-three matched pairs were selected for evaluation after propensity matching. Data of 297 patients (age <65 years) with middle-low rectal cancer who underwent total mesorectal excision + lateral lymph node dissection were also collected and reviewed. Clinical and pathological features, postoperative outcomes and survival data were collected and analyzed. RESULTS: Compared with the total mesorectal excision group, the operation time of patients in the total mesorectal excision + lateral lymph node dissection group was significantly longer (277.6 vs. 171.4 min, P < 0.001), and the estimated blood loss was significantly more (119.6 vs. 57.5 ml, P = 0.014). Although there was no significant difference in overall complications (24.1% vs. 14.4%, P = 0.115) and grade 3-5 complications (9.6% vs. 7.2%, P = 0.576) between the two groups, the incidence of urinary retention (10.8% vs. 2.4%, P = 0.029) was higher in the total mesorectal excision + lateral lymph node dissection group. Two groups of patients achieve a similar 3-year overall survival (92.8% vs. 85.4%, P = 0.195) and 3-year disease-free survival (81.5% vs. 73.0%, P = 0.625). In addition, we compared long-term outcomes in 110 elderly patients with total mesorectal excision + lateral lymph node dissection and 297 non-elderly patients with total mesorectal excision + lateral lymph node dissection, and the results showed that 3-year (89.2% vs. 80.9%, P = 0.546) and disease-free survival (76.4% vs. 70.4%, P = 0.346) were similar between elderly and non-elderly patients. CONCLUSIONS: Although urinary retention is closely related to the implementation of lateral lymph node dissection in elderly patients, total mesorectal excision with lateral lymph node dissection could be performed safely with accepted overall and grade 3-5 postoperative complications in elderly patients with rectal cancer. Moreover, elderly patients with clinical lateral lymph node metastasis can also benefit from lateral lymph node dissection as well as younger patients. Prospective studies with large sample sizes are needed to verify our results further.

Two-team lateral lymph node dissection assisted by the transanal approach for locally advanced lower rectal cancer: comparison with the conventional transabdominal approach.

BACKGROUND: An optimal surgical approach to lateral lymph node dissection (LLND) remains controversial. With the recent popularity of transanal total mesorectal excision, a two-team procedure combining the transabdominal and transanal approaches was established as a novel approach to LLND. This study aimed to clarify the safety and feasibility of two-team LLND (2team-LLND) and compare its short-term outcomes with those of conventional transabdominal LLND (Conv-LLND). METHODS: Between April 2013 and March 2020, 463 patients diagnosed with primary locally advanced rectal cancer underwent a transanal total mesorectal excision; among them, 93 patients who underwent bilateral prophylactic LLND were included in this single-center, retrospective study. Among these patients, 50 and 43 patients underwent Conv-LLND (the Conv-LLND group) and 2team-LLND (the 2team-LLND group), respectively. The short-term outcomes, including the operation time, blood loss volume, number of complications, and number of harvested lymph nodes, were compared between the two groups. RESULTS: The intraoperative and postoperative complications in the 2team-LLND group were equivalent to those in the Conv-LLND group; furthermore, the incidence of postoperative urinary retention in the 2team-LLND group was acceptably low (9%). Compared with the Conv-LLND group, the 2team-LLND group had a significantly shorter operation time (P = 0.003), lower median blood loss (P = 0.02), and higher number of harvested lateral lymph nodes (P = 0.0005). CONCLUSION: The intraoperative and postoperative complications of 2team-LLND were comparable with those of Conv-LLND. Thus, 2team-LLND was safe and feasible for advanced lower rectal cancer. Moreover, it was superior to Conv-LLND in terms of the operation time, blood loss volume, and number of harvested lateral lymph nodes. Therefore, it can be a promising LLND approach.

Comparison of robotic versus laparoscopic lateral lymph node dissection for advanced lower rectal cancer: a retrospective study at two institutions.

BACKGROUND: Lateral lymph node dissection (LLND) represents a technically challenging procedure. This study aimed to evaluate the perioperative, genitourinary functional and mid-term oncological outcomes of laparoscopic lateral lymph node dissection (LLLND) and robotic lateral lymph node dissection (RLLND) for advanced lower rectal cancer (ALRC). METHODS: Between January 2015 and April 2021, consecutive patients who underwent RLLND and LLLND at two high-volume centres were enrolled. The perioperative outcomes, genitourinary function recovery and mid-term oncological outcomes of the patients were compared. A subgroup analysis of patients who underwent neoadjuvant chemoradiotherapy (nCRT) was performed. RESULTS: A total of 205 patients were included in the analysis, with 95 in the RLLND group and 110 in the LLLND group. The patients in the RLLND group had a longer operative time, less blood loss, and more harvested internal iliac lymph nodes than did those in the LLLND group. In postoperative complication, urinary retention was less frequent in the RLLND group than in the LLLND group. Additionally, the RLLND group had better genitourinary function recovery. Similar results were also observed from the nCRT subgroup analysis. Moreover, there was no significant difference in mid-term oncological outcomes between the two groups. Further subgroup analysis indicated that the patients who underwent nCRT + LLLND/RLLND had better local control than those who underwent only LLLND/RLLND. CONCLUSIONS: RLLND is safe and feasible for ALRC and is associated with more harvested internal iliac lymph nodes and better genitourinary function recovery. NCRT combined with minimally invasive LLND could constitute an improved strategy for ALRC.

Transanal lateral lymph node dissection with intraoperative hologram support in low rectal cancer.

BACKGROUND: In Japan, the standard treatment for stage II/III advanced low rectal cancer is total mesorectal excision plus lateral lymph node dissection (LLND). There are also recent reports on the use of transanal LLND. However, the transanal anatomy is difficult to understand, and additional support tools are required to improve the surgical safety. The present study examined the utility of holograms with mixed reality as an intraoperative support tool for assessing the complex pelvic anatomy. METHODS: Polygon (stereolithography) files of patients' pelvic organs were created and exported from the SYNAPSE VINCENT imaging system and uploaded into the Holoeyes MD virtual reality software. Three-dimensional images were automatically converted into patient-specific holograms. Each hologram was then installed into a head mount display (HoloLens2), and the surgeons and assistants wore the HoloLens2 when they performed transanal LLND. Twelve digestive surgeons with prior practice in hologram manipulation evaluated the utility of the intraoperative hologram support by means of a questionnaire. RESULTS: Intraoperative hologram support improved the surgical understanding of the lateral lymph node region anatomy. In the questionnaire, 75% of the surgeons answered that the hologram accurately reflected the anatomy, and 92% of the surgeons answered that the anatomy was better understood by simulating the hologram intraoperatively than preoperatively. Moreover, 92% of the surgeons agreed that intraoperative holograms were a useful support tool for improving the surgical safety. CONCLUSIONS: Intraoperative hologram support improved the surgical understanding of the pelvic anatomy for transanal LLND. Intraoperative holograms may represent a next-generation surgical tool for transanal LLND.

Long-term outcomes of upfront robotic rectal cancer surgery: a single-center, retrospective cohort study in Japan.

PURPOSE: The purpose of this study was to evaluate the long-term outcomes of robotic rectal cancer surgery and to examine the risk factors for recurrence. METHODS: In a high-volume center in Japan, we retrospectively enrolled patients with pStage I-III rectal cancer within 15 cm of the anal verge who underwent robotic surgery from 2011 to 2017. Almost all patients underwent upfront surgery, and lateral lymph-node dissection (LLND) was performed for patients with locally advanced lower rectal cancer. We evaluated the 5-year overall survival (OS), relapse-free survival (RFS), and cumulative local recurrence (LR) rates and examined the risk factors for the RFS. RESULTS: We evaluated 488 patients who underwent robotic rectal cancer surgery, including 5.1% who underwent preoperative chemoradiotherapy to obtain clear resection margins and 33.6% who underwent LLND. There were 203, 87, and 198 patients with pStage I, II, and III, respectively, and the positive resection margin rate was 1.0%. The 5-year OS, RFS, and LR rates were 95.5%, 81.7%, and 2.2%, respectively. The independent risk factors for the RFS were the presence of venous invasion, extramural tumor deposits without lymph-node structure, and pT ≥ 3. CONCLUSION: This study demonstrated the favorable long-term outcomes of robotic rectal cancer surgery.

Current status of transanal total mesorectal excision for rectal cancer and the expanding indications of the transanal approach for extended pelvic surgeries.

Transanal total mesorectal excision (taTME) has been rapidly accepted as a promising surgical approach to the distal rectum. The benefits include ease of access to the bottom of the deep pelvis linearly over a short distance in order to easily visualize the important anatomy. Furthermore, the distal resection margins can be secured under direct vision. Additionally, a two-team approach combining taTME with a transabdominal approach could decrease the operative time and conversion rate. Although taTME was expected to become more rapidly popularized worldwide, enthusiasm for it has stalled due to unfamiliar intraoperative complications, a lack of oncologic evidence from randomized trials, and the widespread use of robotic surgery. While international registries have reported favorable short- and medium-term outcomes from taTME, a Norwegian national study reported a high local recurrence rate of 9.5%. The characteristics of the recurrences included rapid, multifocal growth in the pelvis, which was quite different from recurrences following traditional transabdominal TME; thus, the Norwegian Colorectal Cancer Group reached a consensus for a temporary moratorium on the performance of taTME. To ensure acceptable baseline quality and patient safety, taTME should be performed by well-trained colorectal surgeons. Although the appropriate indications for taTME remain controversial, the transanal approach is extremely important as a means of goal setting in difficult TME cases and as an aid to the transabdominal approach in various types of extended pelvic surgeries. The benefits in transanal lateral lymph node dissection and pelvic exenteration are presented herein.

[Risk factors of occult lymph node metastasis of levels â ¢ and â £ in papillary thyroid carcinoma].

Objective: To investigate the potential risk factors for occult lateral cervical lymph node metastasis (LNM) to levels Ⅲ and Ⅳ in patients with papillary thyroid carcinoma (PTC) and the necessity of super-selective lateral lymph node dissection for patients harboring these metastases. Methods: This prospective study included PTC patients who were operated by the same surgeon in the Department of Head and Neck Surgery of Cancer Hospital, Chinese Academy of Medical Sciences from October 2015 through October 2019. Preoperative ultrasound and enhanced Computer Tomography (CT) did not denote suspected enlarged lymph nodes in the lateral neck. All patients underwent lymph node dissection in levels Ⅲ and Ⅳ on the basis of original thyroid collar incision after LNM to level Ⅵ was confirmed by preoperative fine needlebiopsy or intraoperative frozen pathology. Results: Of all 143 patients, 74 (51.7%) had occult LNM in levels Ⅲ and Ⅳ confirmed by postoperative pathology. The average number of metastasized lymph nodes in levels Ⅲ and Ⅳ was 2.64±1.80, and that in level Ⅵ was 3.77±3.27. There was a significant linear positive correlation between the number of metastasized lymph nodes in level Ⅵ and that in levels Ⅲ and Ⅳ (r=0.341, P<0.001). That the metastasized lymph nodes in level Ⅵ equals three was the best predictor of occult lateral LNM to levels Ⅲ and Ⅳ. Univariate analysis showed that age <55 years, tumor size ≥2.0 cm, number of metastasized lymph nodes in level Ⅵ ≥3, and percentage of metastasized lymph nodes in the total number of dissected lymph nodes in level Ⅵ >50% were associated with occult LNM in levels Ⅲ and Ⅳ (P<0.05). Multivariate analysis showed that number of metastasized lymph nodes in level Ⅵ≥3 was an independent risk factor for occult LNM in levels Ⅲ and Ⅳ (P=0.006). Conclusions: Age, tumor size and LNM in level Ⅵ were associated with occult lateral LNM in PTC patients. Lymph node dissection in levels Ⅲ and Ⅳ could be considered for selective patients, since it will help to avoid secondary operation for residual tumor or recurrence resulted from insufficient treatment without increasing the incidence of complications or affecting patients' appearances.

Identification of patient subgroups with low risk of postoperative local recurrence for whom total mesorectal excision surgery alone is sufficient: a multicenter retrospective analysis.

PURPOSE: For rectal cancer, a multimodality approach is mandatory including neoadjuvant chemoradiotherapy, neoadjuvant chemotherapy, and lateral pelvic lymph node (LPLN) dissection, in addition to the total mesorectal excision (TME). However, these treatments are associated with adverse events. It is important to select patients who do or do not need these treatments. METHODS: We retrospectively analyzed patients with cStage II and III rectal cancer who underwent curative resection at three hospitals. Recurrence patterns were classified into three types; pelvic cavity, LPLN, and distant recurrences, and the risk factors for each pattern of recurrence were compared. We then analyzed the risk of recurrence in the patients who underwent TME alone. RESULTS: In total, 506 patients were enrolled in this study. Pelvic cavity recurrence was significantly associated with clinical assumption of circumferential resection margin involvement (cCRM) (p < 0.001), distant recurrence was associated with cN positivity (p < 0.001), and LPLN recurrence was associated with pretreatment LPLN swelling ≥ 5 mm (p < 0.001), lower tumor location (p = 0.016), and serum CEA level > 5 ng/mL (p = 0.008). In patients without cCRM and swollen LPLN, the local recurrence rate was extremely low even if they underwent TME alone; the 5-year recurrence rates of pelvic cavity and LPLN were 2.2% and 1.9%, respectively. CONCLUSION: Additional treatments to TME for rectal cancer need to be performed based on the risk factors for each recurrence pattern.

A randomized controlled trial comparing perioperative vs. postoperative mFOLFOX6 for lower rectal cancer with suspected lateral pelvic lymph node metastasis (JCOG1310): a phase II/III randomized controlled trial.

OBJECTIVE: The optimal perioperative chemotherapy for lower rectal cancer with lateral pelvic lymph node metastasis remains unclear. We evaluated the efficacy and safety of perioperative mFOLFOX6 in comparison with postoperative mFOLFOX6 for rectal cancer patients undergoing total mesorectal excision with lateral lymph node dissection. METHODS: We conducted an open label randomized phase II/III trial in 18 Japanese institutions. We enrolled patients with histologically proven lower rectal adenocarcinoma with clinical pelvic lateral lymph node metastasis who were randomly assigned (1:1) to receive postoperative mFOLFOX6 (12 courses of intravenous oxaliplatin [85 mg/m2] with L-leucovorin [200 mg/m2] followed by 5-fluorouracil [400 mg/m2, bolus and 2400 mg/m2, continuous infusion, repeated every 2 weeks]) or perioperative mFOLFOX6 (six courses each preoperatively and postoperatively). The primary endpoint was overall survival (OS). The trial is registered with Japan Registry of Clinical Trials, number jRCTs031180230. RESULTS: Between May 2015, and May 2019, 48 patients were randomized to the postoperative arm (n = 26) and the perioperative arm (n = 22). The trial was terminated prematurely due to poor accrual. The 3-year OS in the postoperative and perioperative groups were 66.1 and 84.4%, respectively (HR 0.58, 95% CI [0.14-2.45], one-sided P = 0.23). The pathological complete response rate in the perioperative group was 9.1%. Grade 3 postoperative surgical complications were more frequently observed in the perioperative arm (50.0 vs. 12.0%). One treatment-related death due to sepsis from pelvic infection occurred in the postoperative group. CONCLUSIONS: Perioperative mFOLFOX6 may be an insufficient treatment to improve survival of lower rectal cancer with lateral pelvic lymph node metastasis.

Evaluation of the learning curve for robot-assisted rectal surgery using the cumulative sum method.

BACKGROUND: There is no clear evidence on the number of cases required to master the techniques required in robot-assisted surgery for different surgical fields and techniques. The purpose of this study was to clarify the learning curve of robot-assisted rectal surgery for malignant disease by surgical process. METHOD: The study retrospectively analyzed robot-assisted rectal surgeries performed between April 2014 and July 2020 for which the operating time per process was measurable. The following learning curves were created using the cumulative sum (CUSUM) method: (1) console time required for total mesorectal excision (CUSUM tTME), (2) time from peritoneal incision to inferior mesenteric artery dissection (CUSUM tIMA), (3) time required to mobilize the descending and sigmoid colon (CUSUM tCM), and (4) time required to mobilize the rectum (CUSUM tRM). Each learning curve was classified into phases 1-3 and evaluated. A fifth learning curve was evaluated for robot-assisted lateral lymph node dissection (CUSUM tLLND). RESULTS: This study included 149 cases. Phase 1 consisted of 32 cases for CUSUM tTME, 30 for CUSUM tIMA, 21 for CUSUM tCM, and 30 for CUSUM tRM; the respective numbers were 54, 48, 45, and 61 in phase 2 and 63, 71, 83, and 58 in phase 3. There was no significant difference in the number of cases in each phase. Lateral lymph node dissection was initiated in the 76th case where robot-assisted rectal surgery was performed. For CUSUM tLLND, there were 12 cases in phase 1, 6 in phase 2, and 7 cases in phase 3. CONCLUSIONS: These findings suggest that the learning curve for robot-assisted rectal surgery is the same for all surgical processes. Surgeons who already have adequate experience in robot-assisted surgery may be able to acquire stable technique in a smaller number of cases when they start to learn other techniques.

Fluorescence vessel and ureter navigation during laparoscopic lateral lymph node dissection.

BACKGROUND: Lateral lymph node metastasis in lower rectal cancer is considered a local disease in Japan, and guidelines suggest lateral lymph node dissection (LLND). However, laparoscopic procedures are relatively difficult. The ureter and hypogastric fascia must be dissected from the vesicohypogastric fascia to preserve the autonomic nerve and ureter. Additionally, lymph node dissection around the internal iliac artery is complex because many patterns of branching from the internal iliac artery exist. We investigated the utility of fluorescence ureter and vessel navigation using a near-infrared ray fluorescent ureteral catheter (NIRFUC) and indocyanine green (ICG). METHODS: Fourteen patients who underwent laparoscopic LLND using fluorescence navigation were included. Eleven patients had rectal cancer, 1 had anal cancer, and 2 exhibited recurrence of rectal cancer. Eleven patients underwent NIRFUC insertion before surgery. Fluorescence vessel navigation (FVN) was performed with intraoperative ICG injections in 14 patients, with a total of 18 sides. The outcome measures were ureter navigation visibility, detection of the branch form from the internal iliac artery with FVN, differences between the fluorescence findings and anatomy of the internal iliac artery determined after LLND, and the surgical outcome. RESULTS: In all 11 patients, the ureters were clearly identified as fluorescent before dissection around the ureter. FVN revealed the internal iliac, umbilical, and superior vesical arteries in all patients. The branch from the internal iliac artery according to the Adachi classification was revealed on 16 sides (89%). The time from intravenous ICG injection to fluorescence of the internal iliac artery was 38 (17-57) s. The time from intravenous injection to when the vessels were observed as fluorescent was 113 (65-661) s. No ureteral or vessel injuries occurred. CONCLUSIONS: Fluorescence navigation of vessels and the ureter is feasible in laparoscopic LLND and has the potential to increase safety. CLINICAL TRIAL REGISTRATION: Examination of fluorescence navigation for laparoscopic colorectal cancer surgery Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

Combination of extramural venous invasion and lateral lymph node size detected with magnetic resonance imaging is a reliable biomarker for lateral lymph node metastasis in patients with rectal cancer.

PURPOSE: Pathological extramural venous invasion (EMVI) is defined as the active invasion of malignant cells into veins beyond the muscularis propria in colorectal cancer. It is associated with poor prognosis and increases the risk of disease recurrence. Specific findings on MRI (termed MRI-EMVI) are reportedly associated with pathological EMVI. In this study, we aimed to identify risk factors for lateral lymph node (LLN) metastasis related to rectal cancer and to evaluate whether MRI-EMVI could be a new and useful imaging biomarker to help LLN metastasis diagnosis besides LLN size. METHODS: We investigated 67 patients who underwent rectal resection and LLN dissection for rectal cancer. We evaluated MRI-EMVI grading score and examined the relationship between MRI-EMVI and LLN metastasis. RESULTS: Pathological LLN metastasis was detected in 18 cases (26.9%), and MRI-EMVI was observed in 32 cases (47.8%). Patients were divided into two cohorts, according to LLN metastasis. Multivariate analyses demonstrated that higher risk of LLN metastasis was significantly associated with MRI-EMVI (P = 0.0112) and a short lateral lymph node axis (≥ 5 mm) (P = 0.0002). The positive likelihood ratios of MRI-EMVI alone, LLN size alone, and the combination of both factors were 2.12, 4.84, and 16.33, respectively. Patients negative for both showed better 2-year relapse-free survival compared to other patients (84.4% vs. 62.1%, P = 0.0374). CONCLUSIONS: MRI-EMVI was a useful imaging biomarker for identifying LLN metastasis in patients with rectal cancer. The combination of MRI-EMVI and LLN size can improve diagnostic accuracy.