Robotic-assisted laparoscopic versus open lateral lymph node dissection for advanced lower rectal cancer

Short-term Outcomes of Robotic Lateral Pelvic Lymph Node Dissection for Lower Rectal Cancer

INTRODUCTION

Rectal cancer is among the main causes of cancer-related mortalities worldwide, necessitating more effective treatment strategies.　It is considered that lateral pelvic lymph node dissection (LPND) for rectal cancer patients can contribute to local tumor control and that robotic LPND (Rob-LPND) may be more suitable for LPND, due to technical advantages of precise manipulation in a narrow pelvic space.

METHODS

In this retrospective study, we evaluated the short-term outcomes of laparoscopic-LPND (Lap-LPND) versus Rob-LPND in patients undergoing radical surgery for rectal cancer.　Operative time, blood loss, urethral catheter reinsertion, duration of pelvic drainage tube placement, drainage volume, and postoperative hospital stay were compared between Lap-LPND and Rob-LPND.

RESULTS

Our findings revealed that Rob-LPND was associated with longer total operation time, but there was no significant difference in operation time between the two LPND techniques.　Urinary catheter re-insertion rates were lower in Rob-LPND; also, significant reductions in drainage tube duration, total drainage volume, and postoperative hospital stay were observed.

CONCLUSION

Rob-LPND may reduce postoperative total drainage volume and shorten postoperative hospital stays.　These improvement in short-term outcomes suggest potential clinical advantages of Rob-LPND.

Learning curve analysis for prophylactic bilateral robot-assisted lateral lymph node dissection for lower rectal cancer: a retrospective study

BACKGROUND

Lateral lymph node dissection (LLND) is an important surgical procedure in the treatment of lower rectal cancer (RC). However, limited data are available regarding the learning curve for robot-assisted LLND (RA-LLND). This study aimed to evaluate the learning curve for prophylactic bilateral RA-LLND for lower RC.

METHODS

We retrospectively analyzed 58 consecutive patients with clinical stage II/III lower RC who had undergone prophylactic bilateral RA-LLND between July 2020 and June 2024. Cumulative sum (CUSUM) analysis was used to evaluate the learning curve for bilateral RA-LLND operative time.

RESULTS

The mean age of patients was 61.5 years, and mean body mass index was 23.4 kg/m2. The proportion of neoadjuvant therapy was 8.6%. Mean prophylactic bilateral RA-LLND operative time was 173.7 min. CUSUM analysis divided the learning curve for prophylactic bilateral RA-LLND operative time into three phases: initial learning phase (20 cases); competence phase (16 cases); and master/proficiency phase (subsequent cases). Mastery of surgical technique was achieved after performing the 36th case. Comparisons of surgical outcomes in terms of operative parameters and complications were made between phases 1 and 2 combined and phase 3. A significant reduction in mean prophylactic bilateral RA-LLND operative time was observed between phases 1 and 2 compared with phase 3 (P < 0.01). Mean blood loss was decreased in phase 3 (40.5 ml) compared to phases 1 and 2 combined (148.2 ml, P < 0.01). The frequencies of overall postoperative complications directly related to LLND and urinary dysfunction were significantly reduced in phase 3 compared to phases 1 and 2 combined (P = 0.04, and P = 0.02, respectively).

CONCLUSIONS

The three phases identified by CUSUM analysis represented characteristics of the learning curve for prophylactic bilateral RA-LLND. These data suggest that 20 cases are required for the early stage of the learning curve, whereas mastery level could be achieved after 36 cases.

Reversed anatomy in transanal lateral lymph node dissection: landmarks and pitfalls

Lateral lymph node dissection (LLND) is getting global attention as an a surgical option to reduce local recurrence in locally advanced rectal cancer. As the transanal total mesorectal excision (TaTME) is gaining popularity worldwide, a novel LLND approach was established adopting a two-team approach that combines the transabdominal and transanal approaches using the TaTME technique. This narrative review describes the advantages, anatomical landmarks, surgical techniques, and pitfalls of transanal LLND (TaLLND). The advantages of TaLLND include a magnified view and enhanced maneuverability of the laparoscopic instruments in the deep pelvis. TaLLND is also beneficial for LLND in patients with a history of pelvic surgery because surgeons can have access to the areas unaffected by previous surgery. To master the TaLLND technique, the procedure should be understood according to the following steps: S4 nerve identification, lateral space entry, lateral dissection, obturator vein, artery, and nerve identification, dissection along the external iliac vein, medial dissection, median and bottom dissection, dissection along the internal iliac artery, and dissection along the obturator nerve. TaLLND can be applied to highly advanced disease that requires combined resection of the major internal iliac vessels, pelvic nerves, or adjacent organs. In such cases, simultaneous transanal and transabdomiinal LLND utilizing a two team approach has advantages as these approaches can provide mutual complementary roles. TaLLND is expected to overcome the difficulty of transabdominal LLND and improve the quality of LLND.

Japanese expert consensus on the standardization of robot-assisted pelvic lymph node dissection in urological surgery: Extent of pelvic lymph node and surgical technique

Pelvic lymph node dissection (PLND) is important for accurate staging and prognosis of prostate and/or bladder cancer. Several guidelines recommend extended PLND for patients with these cancers. However, the therapeutic benefits of extended PLND are unclear. One major reason is that the extent of PLND is not clearly defined. Thus, the working group for standardization of robot-assisted PLND, including nine experienced urologists for PLND in Japan, was launched in January 2023 by the Japanese Society of Endourology and Robotics. This study summarized the discussions to define the individual extent of PLND in urological surgery in a consensus meeting among these experienced urologists. The consensus meeting determined the extent of PLND based on arteries (veins) and anatomical membrane structures rather than a vague concept or approach toward PLND. This concept is expected to allow surgeons to implement the same extent of PLND. Finally, after a total of 10 online web conferences were held, we determined the extent of PLND for the obturator lymph node (LN) area, the internal iliac LN area, the external and common iliac LN area, and the presacral LN area according to the above rules. The extent of PLND suggested here currently does not have a clear therapeutic rationale. Therefore, the extent of our proposed PLND is by no means mandatory. We hope our definition of the extent of PLND will be supported by further evidence of therapeutic benefits for urologic cancers.

Robotic-assisted versus laparoscopic-assisted extended mesorectal excision: a comprehensive meta-analysis and systematic review of perioperative and long-term outcomes

BACKGROUND

Concurrent neoadjuvant chemo-radiation (nCRT) with total mesorectal excision (TME) alone sometimes fails to cure lateral lymph node metastasis (LLNM). Therefore, additional lateral lymph node dissection (LLND) can help in the treatment of these patients. This is what we refer to as extended total mesorectal excision (eTME). Such operations (TME alone or eTME) can be performed using conventional laparoscopic techniques and robotic-assisted techniques as well. Our meta-analysis aims to compare the results of robot-assisted (R-eTME) versus laparoscopic-assisted extended mesorectal excision (L-eTME) in terms of short- and long-term outcomes.

METHODOLOGY

Databases searched using title and abstract included Medline (via PubMed), Web of Science, Scopus, and Embase, up to February 20, 2024. All studies that documented robotic versus laparoscopic procedures for extended total mesorectal excision (R-eTME versus L-eTME) and reported more than two relevant outcomes, were included in the study.

RESULTS

Our meta-analysis demonstrates four significant outcomes (operative time, urinary complications, overall recurrence, and admission days) between the laparoscopic and robotic groups. The robotic approach shows advantages over the laparoscopic approach in these outcomes except for the operative time (minute), which was longer in the robotic group compared to the laparoscopic group. The laparoscopic group is associated with a higher overall recurrence than the robotic group with an Odds Ratio of 2(95% CI, 1-4, p = 0.05).

CONCLUSION

This meta-analysis study showed that the R-eTME group had a lower recurrence rate compared to the L-eTME group. Additionally, hospital admission days increased significantly in the laparoscopic group. Other long-term outcomes did not differ significantly between the two groups. Short-term outcomes were similar, except for more urinary complications in the laparoscopic group. In conclusion, the study suggests that robotic surgery may offer advantages over laparoscopic surgery for eTME. Further research and analysis could provide further insight into the potential benefits of robotic surgery in this procedure, particularly when surgeon experience, center volume, and learning curve are taken into consideration.

Robotic versus open and laparoscopic pelvic exenterations for pelvic cancer: a multicenter propensity-matched analysis in Japan

BACKGROUND

Pelvic exenteration (PE) is the last resort for achieving a complete cure for pelvic cancer; however, it is burdensome for patients. Minimally invasive surgeries, including robot-assisted surgery, have been widely used to treat malignant tumors and have also recently been used in PE. This study aimed to evaluate the safety and efficacy of robot-assisted PE (RPE) by comparing the outcomes of open PE (OPE) with those of conventional laparoscopic PE (LPE) for treating pelvic tumors.

METHODS

Following the ethics committee approval, a multicenter retrospective analysis of patients who underwent pelvic exenteration between January 2012 and October 2022 was conducted. Data on patient demographics, tumor characteristics, and perioperative outcomes were collected. A 1:1 propensity score-matched analysis was performed to minimize group selection bias.

RESULTS

In total, 261 patients met the study criteria, of whom 61 underwent RPE, 90 underwent OPE, and 110 underwent LPE. After propensity score matching, 50 pairs were created for RPE and OPE and 59 for RPE and LPE. RPE was associated with significantly less blood loss (RPE vs. OPE: 408 mL vs. 2385 ml, p < 0.001), lower transfusion rate (RPE vs. OPE: 32% vs. 82%, p < 0.001), and lower rate of complications over Clavien-Dindo grade II (RPE vs. OPE: 48% vs. 74%, p = 0.013; RPE vs. LPE: 48% vs. 76%, p = 0.002).

CONCLUSION

This multicenter study suggests that RPE reduces blood loss and transfusion compared with OPE and has a lower rate of complications compared with OPE and LPE in patients with locally advanced and recurrent pelvic tumors.

Surgical navigation for targeted retroperitoneal lymph-node removal: a randomised, controlled, phase 3 trial

Background

Metastatic retroperitoneal lymph node dissection (LND) for nodal recurrence is applied for a variety of cancers, such as urological, gynaecological and rectal cancer. Precise localisation and resection of these lymph nodes (LNs) during surgery can be challenging, especially after previous radiotherapy or surgery. The objective of this study was to assess the added value of surgical navigation for targeted LND in the retroperitoneum.

Methods

We performed an open-label randomised, controlled, phase 3 trial at the Netherlands Cancer Institute, Amsterdam. Eligible participants were over 18 years of age, scheduled for targeted retroperitoneal LND by laparotomy, with removal of one or more suspected (targeted) LN(s) as assessed by diagnostic imaging. Patients were randomised (1:1) between conventional LND and LND using surgical navigation, by means of a minimisation method stratified for tumour origin (urological, colorectal and other). For the surgical navigation, a digital 3D model of the patients' anatomy was created from diagnostic CT scans, including delineation of the targeted LN(s). The 3D model was linked to the patients' position in the operation room. Using an electromagnetic tracking system, with a sterile tracked pointer, the actual position of the pointer was shown in the 3D model, enabling the surgeon to localize the targeted LN(s). The primary outcome of the study was the percentage of successful procedures. Success was defined as no residual target LN(s) visible on postoperative CT imaging. This study was registered with ClinicalTrials.gov, NCT05867095.

Findings

From January 2017 to December 2020, 69 participants were included in the study, 35 (51%) in the conventional arm and 34 (49%) in the navigation arm. Four patients were not evaluable and excluded from further analysis; three in the conventional arm (patients withdraw from study participation), one in the navigation arm (discontinued surgery, misclassified diagnosis). According to intention-to-treat analysis, 50% (16/32) of the surgical procedures was successful in the conventional arm, versus 85% (28/33) in the surgical navigation arm (one-tailed p = 0.0028, 90% CI: 14%-56%). Using the Clavien-Dindo classification, the overall complication rate was comparable between the conventional arm and the navigation arm. Surgeons judged the surgical navigation setup as valuable, the median preference score to use surgical navigation was 3.7 (3.3-4.0) (scale 1-5), and the median system usability score was 75 (70-85) (scale 0-100).

Interpretation

Surgical navigation allows for significantly better localisation and removal of target LN(s) in the retroperitoneum.

Funding

This research was supported by the KWF-Alpe d'HuZes (NKI 2014-6596) and by an institutional grant of The Dutch Cancer Society and of the Dutch Ministry of Health, Welfare and Sport.

Comparison of short-term outcomes of laparoscopic surgery, robot-assisted laparoscopic surgery, and open surgery for lateral lymph-node dissection for rectal cancer: a network meta-analysis

This study attempted to compare short-term outcomes of laparoscopic surgery (LS), robot-assisted laparoscopic surgery (RS), and open surgery (OS) for lateral lymph-node dissection (LLND) in treatment of rectal cancer through network meta-analysis. Embase, Web of Science, PubMed, and The Cochrane Library databases were searched to collect cohort studies on outcomes of LS, RS, and OS for LLND for rectal cancer. Newcastle-Ottawa Scale (NOS) was utilized to evaluate the quality of cohort studies. Primary outcomes should at least include one of the following clinical outcome measures: operative time, blood loss, total lymph-node harvest, positive resection margin rate, postoperative complications, and postoperative hospital stay. A network meta-analysis was conducted using STATA software. Fourteen cohort studies including 8612 patients were eligible for inclusion. The network meta-analysis results showed that, in terms of intraoperative outcomes, the RS group had the longest operative time, while the OS group had the shortest; the LS and RS groups had significantly less blood loss than the OS group. In terms of histological outcomes, there were no significant differences in the total number of lymph nodes harvested and the positive margin rate among the LS, RS, and OS groups (P > 0.05). Regarding postoperative outcomes, the OS group had the highest probability of postoperative complications and the longest hospital stay, followed by the LS group, with the RS group being the lowest. RS was the best method in blood loss, postoperative complication rate, and postoperative hospital stay, followed by LS. OS had the shortest operative time and the highest blood loss.

Efficacy of lateral lymph node dissection for local control of rectal cancer: A multicenter study

Background

This study aimed to evaluate the efficacy of lateral lymph node dissection (LLND) for rectal cancer by comparing the local control in patients with and without pathological lateral lymph node metastasis (LLNM).

Methods

We included 189 patients with rectal cancer who underwent total mesorectal excision and LLND at 13 institutions between 2017 and 2019. Patients with and without pathological LLNM were defined as the pLLNM (+) and (-) groups, respectively. Propensity score-matching helped to balance the basic characteristics of both groups. The incidences of local recurrence (LR) and lateral lymph node recurrence (LLNR) were compared between the groups.

Results

In the entire cohort, 39 of the 189 patients had pathological LLNM. The 3-year LR and LLNR rates were 18.3% and 4.0% (p = 0.01) and 7.7% and 3.3% (p = 0.22) in the pLLNM (+) and (-) groups, respectively. After propensity score matching, the data from 62 patients were analyzed. No significant differences in LR or LLNR were observed between both groups. The 3-year LR and LLNR rates were 16.4% and 9.8% (p = 0.46) and 9.7% and 9.8% (p = 0.99) in the pLLNM (+) and (-) groups, respectively.

Conclusion

LLND would lead to comparable local control in the pLLNM (+) and (-) groups if the clinicopathological characteristics except for LLNM are similar.

Management of internal iliac and obturator lymph nodes in mid-low rectal cancer

In rectal cancer treatment, the diagnosis and management of lateral pelvic lymph nodes (LLN) are critical for preventing local recurrence. Over time, scholars have reached a consensus: when imaging suggests LLN metastasis, combining neoadjuvant chemoradiotherapy (nCRT) with selective LLN dissection (LLND) can mitigate the risk of recurrence. Selective LLND typically encompasses lymph nodes in the internal iliac and obturator regions. Recent studies emphasize distinctions between internal iliac and obturator lymph nodes regarding prognosis and treatment outcomes, prompting the need for differentiated diagnostic and treatment approaches.

Short-term and long-term outcomes after robotic radical surgery for rectal gastrointestinal stromal tumor

BACKGROUND

The optimal approach for ensuring both complete resection and preservation of anal function in rectal gastrointestinal stromal tumor (GIST) remains unknown. The aim of this study was to clarify short-term and long-term outcomes after robotic radical surgery for rectal GIST.

METHODS

A total of 13 patients who underwent robotic radical surgery for rectal GIST between December 2011 and April 2022 were included. All robotic procedures were performed using a systematic approach. A supplemental video of robotic radical surgery for rectal GIST is attached. The short-term outcome was the incidence of postoperative complications during the first 30 days after surgery. Surgical outcomes were retrieved from a prospective database. Long-term outcomes, including overall survival and recurrence-free survival, were determined in all patients.

RESULTS

Median distance from the tumor to the anal verge was 4.0 cm. Surgical margins were negative in all patients. Two patients underwent neoadjuvant imatinib therapy. All patients underwent sphincter-preserving surgery. None underwent conversion to open or laparoscopic surgery. The incidence of postoperative Clavien-Dindo grade II and grade ≥ III complications was 7.7% and 0%, respectively. The median postoperative hospital stay was 7 days. Twelve patients (92.3%) underwent stoma closure within 5 months of the initial surgery. Median follow-up time was 76 months. The 5-year overall survival and recurrence-free survival rates were both 100%. None of the patients had recurrence.

CONCLUSION

Short-term and long-term outcomes after radical robotic surgery for rectal GIST were favorable. Robotic surgery might be a useful surgical approach for rectal GIST.

Management of lateral pelvic lymph nodes in rectal cancer: Is it time to reach an Agreement?

In this editorial, we proceed to comment on the article by Chua et al, addressing the management of metastatic lateral pelvic lymph nodes (mLLN) in stage II/III rectal cancer patients below the peritoneal reflection. The treatment of this nodal area sparks significant controversy due to the strategic differences followed by Eastern and Western physicians, albeit with a higher degree of convergence in recent years. The dissection of lateral pelvic lymph nodes without neoadjuvant therapy is a standard practice in Eastern countries. In contrast, in the West, preference leans towards opting for neoadjuvant therapy with chemoradiotherapy or radiotherapy, that would cover the treatment of this area without the need to add the dissection of these nodes to the total mesorectal excision. In the presence of high-risk nodal characteristics for mLLN related to radiological imaging and lack of response to neoadjuvant therapy, the risk of lateral local recurrence increases, suggesting the appropriate selection of strategies to reduce the risk of recurrence in each patient profile. Despite the heterogeneous and retrospective nature of studies addressing this area, an international consensus is necessary to approach this clinical scenario uniformly.

Two cases of strangulated bowel obstruction due to exposed vessel and nerve after laparoscopic and robot-assisted lateral lymph node dissection (LLND) for rectal cancer

BACKGROUND

The majority of small bowel obstructions (SBO) are caused by adhesion due to abdominal surgery. Internal hernias, a very rare cause of SBO, can arise from exposed blood vessels and nerves during pelvic lymphadenectomy (PL). In this report, we present two cases of SBO following laparoscopic and robot-assisted lateral lymph node dissection (LLND) for rectal cancer, one case each, of which obstructions were attributed to the exposure of blood vessels and nerves during the procedures.

CASE PRESENTATION

Case 1: A 68-year-old man underwent laparoscopic perineal rectal amputation and LLND for rectal cancer. Four years and three months after surgery, he visited to the emergency room with a chief complaint of left groin pain. Computed tomography (CT) revealed a closed-loop in the left pelvic cavity. We performed an open surgery to find that the small intestine was fitted into the gap between the left obturator nerve and the left pelvic wall, which was exposed by LLND. The intestine was not resected because coloration and peristalsis of the intestine improved after the hernia was released. The obturator nerve was preserved. Case 2: A 57-year-old man underwent a robot-assisted rectal amputation with LLND for rectal cancer. Eight months after surgery, he presented to the emergency room with a complaint of abdominal pain. CT revealed a closed-loop in the right pelvic cavity, and he underwent a laparoscopic surgery with a diagnosis of strangulated SBO. The small intestine was strangulated by an internal hernia caused by the right umbilical arterial cord, which was exposed by LLND. The incarcerated small intestine was released from the gap between the umbilical arterial cord and the pelvic wall. No bowel resection was performed. The umbilical arterial cord causing the internal hernia was resected.

CONCLUSION

Although strangulated SBO due to an exposed intestinal cord after PL has been a rare condition to date, it is crucial for surgeons to keep this condition in mind.

Long-term outcomes of robot-assisted laparoscopic surgery versus conventional laparoscopic surgery for rectal cancer: single-center, retrospective, propensity score analyses

Although the short-term outcomes of robot-assisted laparoscopic surgery (RALS) for rectal cancer are well known, the long-term oncologic outcomes of RALS compared with those of conventional laparoscopic surgery (CLS) are not clear. This study aimed to compare the long-term outcomes of RALS and CLS for rectal cancer using propensity score matching. This retrospective study included 185 patients with stage I-III rectal cancer who underwent radical surgery at our institute between 2010 and 2019. Propensity score analyses were performed with 3-year overall survival (OS) and relapse-free survival (RFS) as the primary endpoints. After case matching, the 3-year OS and 3-year RFS rates were 86.5% and 77.9% in the CLS group and 98.4% and 88.5% in the RALS group, respectively. Although there were no significant differences in OS (p = 0.195) or RFS (p = 0.518) between the groups, the RALS group had slightly better OS and RFS rates. 3-year cumulative (Cum) local recurrence (LR) and 3-year Cum distant metastasis (DM) were 9.7% and 8.7% in the CLS group and 4.5% and 10.8% in the RALS group, respectively. There were no significant differences in Cum-LR (p = 0.225) or Cum-DM (p = 0.318) between the groups. RALS is a reasonable surgical treatment option for patients with rectal cancer, with long-term outcomes similar to those of CLS in such patients.

A comparative study of the pathological outcomes of robot-assisted versus open surgery for rectal cancer

PURPOSE

The use of robot-assisted surgery for rectal cancer is increasing, but the pathological outcomes have not been fully clarified. We compared the surgical and pathological outcomes between robot-assisted and open surgery in specimens from patients operated on for rectal cancer.

METHODS

All patients who underwent resection for rectal cancer from 2016 to 2018 were included (n=137). Specimens were divided into 3 sections to analyze the pathology of the lymph nodes.

RESULTS

The total specimen lengths were shorter in the robot-assisted group than in the open surgery group (mean±standard deviation: 29.1±8.6 cm vs. 33.8±9.9 cm, P=0.004) because of a shorter proximal resection margin (21.7±8.7 cm vs. 26.4±10.6 cm, P=0.006). The number of recruited lymph nodes (35.8±21.8 vs. 39.6±16.5, P=0.604) and arterial vessel length (8.84±2.6 cm vs. 8.78±2.4 cm, P=0.891) did not differ significantly between the 2 surgical approaches. Lymph node metastases were found in 33 of 137 samples (24.1%), but the numbers did not differ significantly between the procedures. Among these 33 cases, metastatic lymph nodes were located in the mesorectum (75.8%), in the sigmoid colon mesentery (33.3%), and at the arterial ligation site of the inferior mesenteric artery (12.1%). The circumferential resection margin and the proportion of complete mesorectal fascia were comparable between the groups.

CONCLUSION

There were no significant differences between the 2 surgical approaches regarding arterial vessel length, recruitment of lymph node metastases, and resection margins.

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.

A systematic review and meta-analysis of minimally invasive versus conventional open proctectomy for locally advanced colon cancer

BACKGROUND

Locally advanced colon cancer is considered a relative contraindication for minimally invasive proctectomy (MIP), and minimally invasive versus conventional open proctectomy (COP) for locally advanced colon cancer has not been studied.

METHODS

We have searched the Embase, Cochrane Library, PubMed, Medline, and Web of Science for articles on minimally invasive (robotic and laparoscopic) and COP. We calculated pooled standard mean difference (SMD), relative risk (RR), and 95% confidence intervals (CIs). The protocol for this review has been registered on PROSPERO (CRD42023407029).

RESULTS

There are 10132 participants including 21 articles. Compared with COP, patients who underwent MIP had less operation time (SMD 0.48; CI 0.32 to 0.65; I2 = 0%, P = .000), estimated blood loss (MD -1.23; CI -1.90 to -0.56; I2 = 95%, P < .0001), the median time to semi-liquid diet (SMD -0.43; CI -0.70 to -0.15; I2 = 0%, P = .002), time to the first flatus (SMD -0.97; CI -1.30 to -0.63; I2 = 7%, P < .0001), intraoperative blood transfusion (RR 0.33; CI 0.24 to 0.46; I2 = 0%, P < .0001) in perioperative outcomes. Compared with COP, patients who underwent MIP had fewer overall complications (RR 0.85; CI 0.73 to 0.98; I2 = 22.4%, P = .023), postoperative complications (RR 0.79; CI 0.69 to 0.90; I2 = 0%, P = .001), and urinary retention (RR 0.63; CI 0.44 to 0.90; I2 = 0%, P = .011) in perioperative outcomes.

CONCLUSION

This study comprehensively and systematically evaluated the difference between the safety and effectiveness of minimally invasive and open treatment of locally advanced colon cancer through meta-analysis. Minimally invasive proctectomy is better than COP in postoperative and perioperative outcomes. However, there is no difference in oncological outcomes. This also provides an evidence-based reference for clinical practice. Of course, multi-center RCT research is also needed to draw more scientific and rigorous conclusions in the future.

Current perspectives on the management of lateral pelvic lymph nodes in rectal cancer

Significant controversies exist with regards to the optimal management of lateral pelvic lymph nodes metastases (mLLN) in patients with low rectal cancer. The differing views held by Japanese and Western clinicians on the management of mLLN have been well documented. However, the adequacy of pelvic lymph node dissection (PLND) or neoadjuvant chemoradiation (NACRT) alone in addition to total mesorectal excision (TME) have recently come into question, due to the relatively high incidence of lateral local recurrences following PLND and TME, or NACRT and TME alone. Recently, a more selective approach to PLND has been suggested, involving a combination of neoadjuvant therapy, followed by PLND only to patients in whom the oncological benefit is likely to outweigh the risk of potential adverse events. A number of studies have attempted to retrospectively identify certain nodal characteristics on preoperative imaging, such as nodal size, appearance, and size reduction following neoadjuvant therapy. However, no consensus has been reached regarding the optimal criteria for a selective approach to PLND, partly due to the heterogeneity and retrospective nature of most of these studies. This review aims to provide an overview of recent evidence with regards to the diagnostic challenges, considerations for, and outcomes of the current management strategies for mLLN in rectal cancer patients.

Robotic Lateral Pelvic Lymph Node Dissection in Rectal Cancer: A Feasibility Study from a European Centre

INTRODUCTION

The role of robotic lateral pelvic lymph node dissection (LPLND) for lateral pelvic nodal disease (LPND) in rectal cancer has yet to be investigated in the Western hemisphere. This study aims to investigate the safety and feasibility of robotic LPLND by utilising a well-established totally robotic TME protocol.

METHODS

We conducted a retrospective study on 17 consecutive patients who underwent robotic LPLND for LPND ± TME for rectal cancer between 2015 and 2021. A single docking totally robotic approach from the left hip with full splenic mobilisation was performed using the X/Xi da Vinci platform. All patients underwent a tri-compartmental robotic en bloc excision of LPND with preservation of the obturator nerve and pelvic nerve plexus, leaving a well-skeletonised internal iliac vessel and its branches.

RESULTS

The median operative time was 280 min, which was 40 min longer than our standard robotic TME. The median BMI was 26, and there were no conversions. The median inpatient stay was 7 days with no Clavien-Dindo > 3 complications. One patient (6%) developed local recurrence and metastatic disease within 5 months. The proportion of histologically confirmed LPND was 41%, of which 94% were well to moderately differentiated adenocarcinoma. Median pre-operative lateral pelvic node size was significantly higher in positive nodes (14 mm vs. 8 mm (p = 0.01)). All patients had clear resection margins on histology.

DISCUSSION

Robotic LPLND is safe and feasible with good peri-operative and short-term outcomes, with the ergonomic advantages of a robotic TME docking protocol readily transferrable in LPLND.

Robot-assisted lateral pelvic lymph node dissection in patients with advanced rectal cancer: a single-center experience of 65 cases

The treatment of lateral pelvic lymph node (LPLN) metastasis of rectal cancer has evolved because of technical difficulties from open surgery to laparoscopy and, recently, robot-assisted surgery. This study aimed to evaluate the technical feasibility and short- and long-term outcomes of robot-assisted LPLN dissection (LPND) following total mesorectal excision (TME) in advanced rectal cancer. Clinical data of 65 patients who underwent robotic-assisted TME with LPND from April 2014 to July 2022 were reviewed. Data regarding operative details, postoperative morbidity (within 90 postoperative days) for short-term outcomes and lateral recurrence as long-term outcomes were analyzed. Among the 65 patients with LPND, preoperative chemoradiotherapy was performed in 49 (75.4%). The mean operative time was 306.8 (range 191-477) min, and the mean time of unilateral LPND was 38.6 (range 16-66) min. LPND was bilaterally performed in 19 (29.2%) patients. The mean number of each side of harvested LPLNs was 6.8. Lymph node metastasis was observed in 15 (23.0%) patients, and 10 (15.4%) patients had postoperative complications. Lymphocele (n = 3) and pelvic abscess (n = 3) were the most common, followed by voiding difficulty, erectile dysfunction, obturator neuropathy, and sciatic neuropathy (all n = 1). During the 25 months of median follow-up, no lateral recurrence of the LPND site was noted. Robot-assisted LPND following TME is safe and feasible and showed acceptable short- and long-term outcomes. Despite some study limitations, we may be able to apply this strategy more widely through subsequent prospective controlled studies.

Robotic versus laparoscopic approach for minimally invasive lateral pelvic lymph node dissection of advanced lower rectal cancer: a retrospective study comparing short-term outcomes

PURPOSE

The importance of lateral pelvic lymph node dissection (LLND) for advanced low rectal cancer is gradually being recognized in Europe and the USA, where some patients were affected by uncontrolled lateral pelvic lymph node (LLNs) metastasis, even after total mesorectal excision (TME) with neoadjuvant chemoradiotherapy (CRT). The purpose of this study was thus to compare robotic LLND (R-LLND) with laparoscopic (L-LLND) to clarify the safety and advantages of R-LLND.

METHODS

Sixty patients were included in this single-institution retrospective study between January 2013 and July 2022. We compared the short-term outcomes of 27 patients who underwent R-LLND and 33 patients who underwent L-LLND.

RESULTS

En bloc LLND was performed in significantly more patients in the R-LLND than in the L-LLND group (48.1% vs. 15.2%; p = 0.006). The numbers of LLNs on the distal side of the internal iliac region (LN 263D) harvested were significantly higher in the R-LLND than in the L-LLND group (2 [0-9] vs. 1 [0-6]; p = 0.023). The total operative time was significantly longer in the R-LLND than in the L-LLND group (587 [460-876] vs. 544 [398-859]; p = 0.003); however, the LLND time was not significantly different between groups (p = 0.718). Postoperative complications were not significantly different between the two groups.

CONCLUSION

The present study clarified the safety and technical feasibility of R-LLND with respect to L-LLND. Our findings suggest that the robotic approach offers a key advantage, allowing significantly more LLNs to be harvested from the distal side of the internal iliac region (LN 263D). Prospective clinical trials examining the oncological superiority of R-LLND are thus necessary in the near future.

The impact of mesorectal fat area on recurrence following total mesorectal excision for lower rectal cancer

BACKGROUND

The mesorectal fat area (MFA) at the tip of the ischial spines on magnetic resonance imaging has been used to characterize mesorectal morphology. Recent studies reported that a larger MFA correlated with difficulties in rectal cancer surgery. However, the relationship between MFA and rectal cancer prognosis remains unclear. This study evaluated the impact of MFA on recurrence following robotic total mesorectal excision (TME) for rectal cancer.

METHODS

Patients who underwent robotic TME for lower rectal cancer from December 2011 to December 2016 were enrolled. Cox regression analysis was performed to determine variables associated with relapse-free survival (RFS). Patients were divided into groups based on MFA, and RFS was compared.

RESULTS

Of 230 patients, 173 (75.3%) were male. The median age was 63 years, and median MFA was 19.7 cm2. In multivariate analysis, smaller MFA (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.88-0.97; p < 0.01), p/yp stage II (HR, 3.81; 95% CI, 1.40-10.35; p < 0.01), and p/yp stage III (HR, 5.35; 95% CI, 1.88-15.27; p < 0.01) were independently associated with worse RFS. Sex, body mass index, and visceral fat area were not correlated with RFS. In the median follow-up period of 60.8 months, patients with MFA < 19.7 cm2 had a significantly lower 5-year RFS rate (72.7%) than those with MFA ≥ 19.7 cm2 (85.0%).

CONCLUSIONS

Smaller MFA was associated with worse RFS in patients undergoing robotic TME for lower rectal cancer. MFA is considered to be a prognostic factor in rectal cancer.

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.

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.

Essential updates 2020/2021: Advancing precision medicine for comprehensive rectal cancer treatment

In the paradigm shift related to rectal cancer treatment, we have to understand a variety of new emerging topics to provide appropriate treatment for individual patients as precision medicine. However, information on surgery, genomic medicine, and pharmacotherapy is highly specialized and subdivided, creating a barrier to achieving thorough knowledge. In this review, we summarize the perspective for rectal cancer treatment and management from the current standard-of-care to the latest findings to help optimize treatment strategy.

Current Status of Robotic Gastrointestinal Surgery

Development of surgical support robots began in the 1980s as a navigation and auxiliary device for endoscopic surgery. For remote surgery on the battlefield, a master-slave-type surgical support robot was developed, in which a console surgeon operates the robot at will. The da Vinci surgical system, which currently dominates the global robotic surgery market, received United States Food and Drug Administration and regulatory approval in Japan in 2000 and 2009 respectively. The latest, fourth generation, da Vinci Xi has a good field of view via a three-dimensional monitor, highly operable forceps, a motion scale function, and a tremor-filtered articulated function. Gastroenterological tract robotic surgery is safe and minimally invasive when accessing and operating on the esophagus, stomach, colon, and rectum. The learning curve is said to be short, and robotic surgery will likely be standardized soon. Therefore, robotic surgery training should be systematized for young surgeons so that it can be further standardized and later adapted to a wider range of surgeries. This article reviews current trends and potential developments in robotic surgery.

Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: A single-center retrospective cohort study

INTRODUCTION

Whether rectal cancer surgery by robotic-assisted laparoscopic surgery provides beneficial advantages remains controversial. Although favorable outcomes in terms of the safety and technical feasibility of robotic-assisted laparoscopic surgery have been demonstrated for rectal cancer, long-term oncological outcomes for robotic-assisted laparoscopic surgery have only been examined in a few studies. This retrospective study of subjects who underwent robotic-assisted laparoscopic surgery evaluated short- and long-term outcomes of consecutive rectal cancer patients.

METHODS

Between November 2016 and January 2020, we analyzed the records of 62 consecutive patients who underwent robotic-assisted laparoscopic surgery for rectal adenocarcinoma without distant metastasis to evaluate short- and long-term outcomes.

RESULTS

Tumors were located in the lower or mid-rectum (88.7%) in most patients. The median operative time was 357 min. No patient received transfusions, and the median blood loss was 10.5 ml. Open laparotomy was not required in any patient. A Clavien-Dindo classification of all grades was observed in 12 patients (19.4%). Positive radial margin was not observed in any patient. Duration of median follow-up was 40.5 mo, while 3-y overall survival and 3-y relapse-free survival rates were 96.8% and 85.0%, respectively. The local recurrence rate was 3.4%.

CONCLUSION

Favorable short- and long-term outcomes demonstrated robotic-assisted laparoscopic surgery was safe and technically feasible for rectal cancer.

Comparison between robotic-assisted and laparoscopic sphincter-preserving operations for ultra-low rectal cancer

Aim

Sphincter-preserving operations for ultra-low rectal cancer include low anterior and intersphincteric resection. In low anterior resection, the distal rectum is divided by a transabdominal approach, which is technically demanding. In intersphincteric resection, a perineal approach is used. We aimed to evaluate whether robotic-assisted surgery is technically superior to laparoscopic surgery for ultra-low rectal cancer. We compared the frequency of low anterior resection in cases of sphincter-preserving operations.

Method

We investigated 183 patients who underwent sphincter-preserving robotic-assisted or laparoscopic surgery for ultra-low rectal cancer (lower border within 5 cm of the anal verge) between April 2010 and March 2020. The frequency of low anterior resection was compared between laparoscopic and robotic-assisted surgeries. The clinicopathological factors associated with an increase in performing low anterior resection were analyzed by multivariate analyses.

Results

Overall, 41 (22.4%) and 142 (77.6%) patients underwent laparoscopic and robotic-assisted surgery, respectively. Patient characteristics were similar between the groups. Low anterior resection was done significantly more frequently in robotic-assisted surgery (67.6%) than in laparoscopic surgery (48.8%) (P = 0.04). Multivariate analyses showed that tumor distance from the anal verge (P < 0.01) and robotic-assisted surgery (P = 0.02) were significantly associated with an increase in the performance of low anterior resection. The rate of postoperative complications or pathological results was similar between the groups.

Conclusion

Compared with laparoscopic surgery, robotic-assisted surgery significantly increased the frequency of low anterior resection in sphincter-preserving operations for ultra-low rectal cancer. Robotic-assisted surgery has technical superiority over laparoscopic surgery for ultra-low rectal cancer treatment.

Short-term outcomes of robotic-assisted surgery following neoadjuvant chemotherapy for lower rectal cancer

INTRODUCTION

There have been reports about robotic surgery for rectal cancer with chemoradiotherapy (CRT), but only a few studies have compared the use of robotic surgery with and without neoadjuvant chemotherapy (NAC). The aim of our study was to compare the perioperative outcomes of robotic surgery with and without NAC for lower rectal cancer and to examine the effects of NAC on robotic surgery.

METHODS

From January 2016 to July 2021, we compared the short-term outcomes of 45 patients who did not undergo NAC and 55 patients who underwent NAC.

RESULTS

The rate of sphincter-preserving surgeries was higher in the NAC group than in the non-NAC group (P = .024). The total operative time was significantly longer in the NAC group than in the non-NAC group (P < .001). The rate of lateral lymph node dissection was significantly higher in the NAC group than in the non-NAC group (P < .001). No significant differences were identified in the rate of incisional surgical site infections (SSI), organ/space SSI postoperative bleeding, small bowel obstruction, anastomotic leakage, urinary dysfunction, or urinary infections between the groups. There were eight incidences of lateral lymph node metastasis (15%) and two cases with positive resection margins (4.0%) in the NAC group.

CONCLUSIONS

Robotic surgery after NAC has few complications and a higher sphincter-preserving rate that without NAC.

Robotic pelvic side-wall dissection and en-bloc excision for locally advanced and recurrent rectal cancer: outcomes on feasibility and safety

BACKGROUND

Global differences exist in managing lateral pelvic nodes in rectal cancer. Recent studies demonstrate improved local recurrence rates in patients undergoing lateral pelvic lymph node dissections (LPND) in addition to total mesorectal excision (TME) for advanced lower rectal cancer. This study aims to report on the safety and feasibility of the robotic approach in patients undergoing pelvic sidewall lymph node dissection or en-bloc sidewall resection for advanced lower rectal cancer.

METHODS

Patients who underwent an elective robotic pelvic sidewall lymph node dissection or en-bloc sidewall resection for locally advanced rectal cancer with suspicious lateral lymph nodes or pelvic side wall involvement between January 2018 and March 2021 were included. Demographic, clinical, perioperative and histopathological variables were recorded and analysed.

RESULTS

Eight patients (3 males) with a mean age of 55 (33-73) years and mean body mass index of 26.3 (20.7-30.0) kg/m² were included. The median operative time and blood loss were 458.75 (360-540) min and 143.75 (100-300) mL, respectively. There were no conversions or intra-operative complications. There were three post-operative complications recorded (two ileus and one anastomotic leak which required an endoscopic washout in theatre and intravenous antibiotics thereafter). Median length of stay was 12.75 (7-23) days. All patients had an R0 resection, and the median lateral pelvic lymph node yield was 9.1 (6-14).

CONCLUSION

This series demonstrates the practicality and the safety of the robotic approach in the introduction of this technique for en-bloc resection or LPND in patients with locally advanced rectal cancer.

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.

Two-Team Lateral Pelvic Lymph Node Dissection Assisted By the Transanal Approach

INTRODUCTION

Although lateral pelvic lymph node dissection is considered as a treatment option for advanced rectal cancer, it is technically demanding. Recently, the transanal approach for total mesorectal excision has become increasingly used. In this Technical Note, we describe lateral pelvic lymph node dissection using a 2-team method that was assisted by the transanal approach.

TECHNIQUE

First, the lateral pelvic area was entered from the anal side by dissection between the S4 sacral splanchnic nerve and levator ani muscle. Then, the fatty tissues including the obturator compartment and the distal part of the internal iliac compartment were separated from the inferior and superior vesical vessels and the bladder wall. Next, the fatty tissues were separated from the lateral pelvic wall. The obturator nerve was isolated and preserved, whereas the obturator vessels were resected at their peripheral end. Then, the fatty tissues were dissected from the bottom plane. Finally, the fatty tissues were dissected from the ventral bladder wall and were completely isolated from the obturator nerve in cooperation with the transabdominal team.

RESULTS

The 2-team method shortened the operative time dramatically and decreased mental and physical burden on the operators during lateral dissection. Assistance with the transanal approach helped with a secure and effective dissection, especially of the most distal parts, such as around the internal pudendal and inferior vesical arteries, because substantial skill is required for the transabdominal approach alone.

CONCLUSIONS

This procedure is useful for the safe and effective performance of lateral pelvic lymph node dissection for patients with rectal cancer.

Lateral lymph node dissection in rectal cancer: State of the art review

Half of the local regional recurrences from rectal cancer are nowadays located in the lateral compartments, most likely due to lateral lymph node (LLN) metastases. There is evidence that a lateral lymph node dissection (LLND) can lower the lateral local recurrence rate. An LLND without neoadjuvant (chemo)radiotherapy in patients with or without suspected LLN metastases has been the standard of care in the East, while Western surgeons believed LLN metastases to be cured by neoadjuvant treatment and total mesorectal excision (TME) only. An LLND in patients without enlarged LLNs might result in overtreatment with low rates of pathological LLNs, but in patients with enlarged LLNs who are treated with (C)RT and TME only, the risk of a lateral local recurrence significantly increases to 20%. Certain Eastern and Western centers are increasingly performing a selective LLND after neoadjuvant treatment in the presence of suspicious LLNs due to new scientific insights, but (inter)national consensus on the indication and surgical approach of LLND is lacking. An LLND is an anatomically challenging procedure with intraoperative risks such as bleeding and postoperative morbidity. It is therefore essential to carefully select the patients who will benefit from this procedure and where possible to perform the LLND in a minimally invasive manner to limit these risks. This review gives an overview of the current evidence of the assessment of LLNs, the indications for LLND, the surgical technique, pitfalls in performing this procedure and the future studies are discussed, aiming to contribute to more (inter)national consensus.

Lateral lymph node dissection in advanced low rectal cancer treatment

Lateral lymph node (LLN) metastasis is a determinant of local recurrence in advanced low rectal cancer. Lateral lymph node dissection (LLND) is effective in removing metastatic lymph nodes, and has been shown to have a decreased local recurrence rate. However, because of its complexity and complications it induces, there is still tremendous controversy about its usage. Neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME) are recommended as a conventional treatment for advanced rectal cancer. However, LLN metastasis and local recurrence still occur despite nCRT with TME. In Japan, TME with LLND is the standard surgical treatment for Stage II/III of advanced low rectal cancer. Before surgery, a proper evaluation of LLN status should be performed. Laparoscopic LLND and robotic-assisted LLND are useful for this. More research is necessary to improve the oncological outcomes of LLND. In this review, we retrospectively examine previous reports about LLND, aiming to emphasize its application prospects to improve patient survival and life quality.

Short- and Long-Term Outcomes of Robotic Surgery for Rectal Neuroendocrine Tumor

Background. The optimal radical surgical approach for rectal neuroendocrine tumor (NET) is unknown. Methods. This study evaluated the short- and long-term outcomes of 27 patients who underwent robotic radical surgery for rectal NET between 2011 and 2019. Results. The median distance from the lower border of the tumor to the anal verge was 5.0 cm. The median tumor size was 9.5 mm. Six patients (22%) had lymph node metastasis. The incidences of postoperative complications of grade II and grade III or more according to the Clavien-Dindo classification were 11% and 0%, respectively. All patients underwent sphincter-preserving surgery, and no patients required conversion to open surgery. The median follow-up time was 48.9 months, and both the 3-year overall survival and relapse-free survival rates were 100%. Conclusions. Short- and long-term outcomes of robotic surgery for rectal NET tumor were favorable. Robotic surgery may be a useful surgical approach for rectal NET.

Effective dissection for rectal cancer with lateral lymph node metastasis based on prognostic factors and recurrence type

PURPOSE

There are no reports showing the significance and effective range of dissection for patients with lateral lymph node metastasis (LLNM). This study aimed to investigate the indications for lateral lymph node dissection (LLND) in patients with LLNM based on prognostic factors and recurrence types.

METHODS

We reviewed 379 patients with advanced rectal cancer who were treated with total mesorectal excision plus LLND. We analyzed background factors and survival times of patients who had LLNM to determine prognostic factors and recurrence types.

RESULTS

Pathological LLNM occurred in 44 (11.6%). Among patients with LLNM, the predictors of poor prognoses, according to univariate analysis, were > 3 node metastases, the presence of node metastasis on both sides, and spreading beyond the internal iliac lymph nodes. Moreover, LLNM beyond the internal iliac region was found to be an independent prognostic risk factor. Twenty-eight of the 44 patients with lateral lymph node metastasis (64%) relapsed, 22 of whom had distant metastases and 11 of whom experienced local recurrences. Among the latter group, nine (20%) and two (5%) had recurrences in the central and lateral pelvis, respectively.

CONCLUSION

The therapeutic benefit of resection was high, especially in patients with ≤ 3 positive lateral lymph nodes, one-sided bilateral lymph node areas, and positive nodes localized near the internal iliac artery.

Prevalence of Metastatic Lateral Lymph Nodes in Asian Patients with Lateral Lymph Node Dissection for Rectal Cancer: A Meta-analysis

IMPORTANCE

Rectal cancers occupy the eighth position worldwide for new cases and deaths for both men and women. These cancers have a high tendency to form metastases in the mesorectum but also in the lateral lymph nodes. The therapeutic approach for the involved lateral lymph nodes remains controversial.

OBJECTIVE

We performed a systematic review and meta-analysis to assess the prevalence of metastatic lateral lymph nodes in patients with lateral lymph node dissection (LLND) for rectal cancer, which seems to be a fundamental and necessary criterion to discuss any possible indications for LLND.

METHODS

Data sources-study selection-data extraction and synthesis-main outcome and measures. We searched MEDLINE, EMBASE and COCHRANE from November 1, 2018, to November 19, 2018, for studies reporting the presence of metastatic lateral lymph nodes (iliac, obturator and middle sacral nodes) among patients undergoing rectal surgery with LLND. Pooled prevalence values were obtained by random effects models, and the robustness was tested by leave-one-out sensitivity analyses. Heterogeneity was assessed using the Q-test, quantified based on the I2 value and explored by subgroup analyses.

RESULTS

Our final analysis included 31 studies from Asian countries, comprising 7599 patients. The pooled prevalence of metastatic lateral lymph nodes was 17.3% (95% CI: 14.6-20.5). The inter-study variability (heterogeneity) was high (I2 = 89%). The pooled prevalence was, however, robust and varied between 16.6% and 17.9% according to leave-one-out sensitivity analysis. The pooled prevalence of metastatic lymph nodes was not significantly different when pooling only studies including patients who received neoadjuvant treatment or those without neoadjuvant treatment (p = 0.44). Meta-regression showed that the pooled prevalence was associated with the sample size of studies (p < 0.05), as the prevalence decreased when the sample size increased.

CONCLUSION

The pooled prevalence of metastatic lateral lymph nodes was 17.3% among patients who underwent rectal surgery with LLND in Asian countries. Further studies are necessary to determine whether this finding could impact the therapeutic strategy (total mesorectal excision with LLND versus total mesorectal excision with neoadjuvant radiochemotherapy).

Optimizing outcomes of colorectal cancer surgery with robotic platforms

Advanced robotic technology makes it easier to perform total mesorectal excision procedures in the narrow pelvis for rectal cancer while maintaining the advantages of minimally invasive surgery. Robotic surgery for rectal cancer leads to lower conversion rates and faster recovery of urogenital function than conventional laparoscopic surgery. However, longer operative time and high cost are major weaknesses of robotic surgery. To date, most other short-term surgical outcomes, pathologic outcomes, and long-term oncologic outcomes of robotic surgery have not shown significant advantages over laparoscopic surgery. However, robotic surgery is still a valid and highly anticipated surgical approach for rectal cancer because it greatly reduces the surgeon's workload and learning curve. There are also advantages when robotic techniques are applied to technically demanding procedures such as lateral pelvic lymph node dissection or intersphincteric resection. The introduction of new surgical robot systems, including the da Vinci® SP system, is expected to expand the applications of robotic surgery and provide new advantages.

Long-term effects of laparoscopic lateral pelvic lymph node dissection on urinary retention in rectal cancer

BACKGROUND

The addition of lateral pelvic lymph node dissection (LPLND) in rectal cancer surgery has been reported to increase the incidence of post-operative urinary retention. Here, we assessed the predictive factors and long-term outcomes of urinary retention following laparoscopic LPLND (L-LPLND) with total mesorectal excision (TME) for advanced lower rectal cancer.

METHODS

This retrospective single-institutional study reviewed post-operative urinary retention in 71 patients with lower rectal cancer who underwent L-LPLND with TME. Patients with preoperative urinary dysfunction or who underwent unilateral LPLND were excluded. Detailed information regarding patient clinicopathologic characteristics, post-void residual urine volume, and the presence or absence of urinary retention over time was collected from clinical and histopathologic reports and telephone surveys. Urinary retention was defined as residual urine > 100 mL and the need for further treatment.

RESULTS

Post-operative urinary retention was observed in 25/71 patients (35.2%). Multivariate analysis revealed that blood loss ≥ 400 mL [odds ratio (OR) 4.52; 95% confidence interval (CI) 1.24-16.43; p = 0.018] and inferior vesical artery (IVA) resection (OR 8.28; 95% CI 2.46-27.81; p < 0.001) were independently correlated with the incidence of urinary retention. Furthermore, bilateral IVA resection caused urinary retention in more patients than unilateral IVA resection (88.9% vs 47.1%, respectively; p = 0.049). Although urinary retention associated with unilateral IVA resection improved relatively quickly, urinary retention associated with bilateral IVA resection tended to persist over 1 year.

CONCLUSION

We identified the predictive factors of urinary retention following L-LPLND with TME, including increased blood loss (≥ 400 mL) and IVA resection. Urinary retention associated with unilateral IVA resection improved relatively quickly. L-LPLND with unilateral IVA resection is a feasible and safe procedure to improve oncological curability. However, if oncological curability is guaranteed, bilateral IVA resection should be avoided to prevent irreversible urinary retention.

Long-term clinical outcomes of total mesorectal excision and selective lateral pelvic lymph node dissection for advanced low rectal cancer: a comparative study of a robotic versus laparoscopic approach

BACKGROUND

The long-term outcomes of minimally invasive lateral pelvic lymph node dissection (LPND) are not completely known. The aim of this study was to compare long-term outcomes between robotic and laparoscopic LPND in low rectal cancer patients with suspected lymph node metastasis in the pelvic sidewall.

METHODS

We retrospectively reviewed the records of all rectal cancer patients who had laparoscopic or robotic total mesorectal excision (TME) with LPND between March 2006 and June 2016. Stage IV patients were excluded. The outcomes of patients who had laparoscopic and robotic TME with LPND were compared.

RESULTS

Twenty-nine patients had laparoscopic LPND and 70 had robotic LPND. No significant differences in patient characteristics were observed between the two groups. The urinary retention rate was lower in the robotic group than in the laparoscopic group (7.1% vs. 24.1%; p = 0.043). During a median follow-up of 44.3 months, the overall recurrence rates were 48.3% and 31.4% in the laparoscopic and robotic groups, respectively (p = 0.175). The 5-year disease-free survival rates were 50.4% and 67.0% in the laparoscopic and robotic groups, respectively (p = 0.227). The 5-year overall survival rates were 65.0% and 92.2% in the laparoscopic and robotic groups, respectively (p = 0.017).

CONCLUSIONS

Robotic TME with LPND is safe and feasible. In particular, it is associated with lower urinary retention. Robotic TME with LPND might yield a similar local recurrence rate and 5-year disease-free survival, but favorable long-term overall survival as compared to the laparoscopic approach. However, considering the retrospective nature and both major variables of TME and LPND involved together, this should be cautiously interpreted.

Comparison of pathologic outcomes of robotic and open resections for rectal cancer: A systematic review and meta-analysis

Objective

The application of robotic surgery for rectal cancer is increasing steadily. The purpose of this meta-analysis is to compare pathologic outcomes among patients with rectal cancer who underwent open rectal surgery (ORS) versus robotic rectal surgery (RRS).

Methods

We systematically searched the literature of EMBASE, PubMed, the Cochrane Library of randomized controlled trials (RCTs) and nonrandomized controlled trials (nRCTs) comparing ORS with RRS.

Results

Fourteen nRCTs, including 2711 patients met the predetermined inclusion criteria and were included in the meta-analysis. Circumferential resection margin (CRM) positivity (OR: 0.58, 95% CI, 0.29 to 1.16, P = 0.13), number of harvested lymph nodes (WMD: −0.31, 95% CI, −2.16 to 1.53, P = 0.74), complete total mesorectal excision (TME) rates (OR: 0.93, 95% CI, 0.48 to 1.78, P = 0.83) and the length of distal resection margins (DRM) (WMD: −0.01, 95% CI, −0.26 to 0.25, P = 0.96) did not differ significantly between the RRS and ORS groups.

Conclusion

Based on the current evidence, robotic resection for rectal cancer provided equivalent pathological outcomes to ORS in terms of CRM positivity, number of harvested lymph nodes and complete TME rates and DRM.

Robotic surgery for clinical T4 rectal cancer: short- and long-term outcomes

BACKGROUND

The optimal surgical approach for clinical T4 (cT4) rectal cancer is unknown. This study was conducted to clarify short- and long-term outcomes of robotic surgery for cT4 rectal cancer.

METHODS

In our retrospective cohort study, we enrolled patients who underwent robotic surgery for cT4 rectal cancer within 15 cm from the anal verge between 2011 and 2018. The short- and long-term outcomes were evaluated.

RESULTS

Of a total of 122 eligible patients, 70 (57%) had cT4a tumors and 52 (43%) had cT4b tumors. Thirty-five patients (29%) had distant metastasis and 21 (17%) underwent preoperative chemoradiotherapy. Thirty-four patients (28%) underwent combined resection of adjacent organs and 43 (35%) underwent lateral lymph node dissection. The median operative time was 288 min and the median blood loss was 11 ml. No patients required conversion to open surgery. The incidences of postoperative complications of grades II, III, and IV or more according to the Clavien-Dindo classification were 17.2%, 3.5%, and 0%, respectively. Seventy-three patients (60%) had pathological T4 tumors, and the incidence of positive resection margins was 4.9%. The median follow-up time was 42.9 months. The 3-year overall survival, disease-free survival, and cumulative local recurrence rates were 87.5%, 70.4%, and 4.0%, respectively.

CONCLUSIONS

The short- and long-term outcomes of robotic surgery for cT4 rectal cancer were favorable. Robotic surgery is considered to be a useful approach for cT4 rectal cancer.

Robotics Total Mesorectal Excision Up To the Minute

Surgical techniques have evolved over the past few decades, and minimally invasive surgery has been rapidly adapted to become a preferred operative approach for treating colorectal diseases. However, many of the procedures remain a technical challenge for surgeons to perform laparoscopically, which has prompted the development of robotic platforms. Robotic surgery has been introduced as the latest advance in minimally invasive surgery. The present article provides an overview of robotic rectal surgery and describes many advances that have been made in the field over the past two decades. More specifically, the introduction of the robotic platform and its benefits, and the limitations of current robotic technology, are discussed. Although the main advantages of robotic surgery over conventional laparoscopy appear to be lower conversion rates and better surgical specimen quality, oncological and functional outcomes appear to be similar to those of other alternatives. Other potential benefits include earlier recovery of voiding and sexual function after robotic total mesorectal excision. Nevertheless, the costs and lack of haptic feedback remain the primary limitations to the widespread use of robotic technology in the field.

Robotic lateral pelvic lymph node dissection after chemoradiation for rectal cancer: a Western perspective

AIM

There are limited outcome data for lateral pelvic lymph node dissection (LPLND) following neoadjuvant chemoradiotherapy (nCRT), particularly in the West. Our aim was to evaluate the short-term perioperative and oncological outcomes of robotic LPLND at a single cancer centre.

METHOD

A retrospective analysis of a prospective database of consecutive patients undergoing robotic LPLND for rectal cancer between November 2012 and February 2020 was performed. The main outcomes were short-term perioperative and oncological outcomes. Major morbidity was defined as Clavien-Dindo grade 3 or above.

RESULTS

Forty patients underwent robotic LPLND during the study period. The mean age was 54 years (SD ± 15 years) and 13 (31.0%) were female. The median body mass index was 28.6 kg/m² (IQR 25.5-32.6 kg/m² ). Neoadjuvant CRT was performed in all patients. Resection of the primary rectal cancer and concurrent LPLND occurred in 36 (90.0%) patients, whilst the remaining 4 (10.0%) patients had subsequent LPLND after prior rectal resection. The median operating time was 420 min (IQR 313-540 min), estimated blood loss was 150 ml (IQR 55-200 ml) and length of hospital stay was 4 days (IQR 3-6 days). The major morbidity rate was 10.0% (n = 4). The median lymph node harvest from the LPLND was 6 (IQR 3-9) and 13 (32.5%) patients had one or more positive LPLNs. The median follow-up was 16 months (IQR 5-33 months), with 1 (2.5%) local central recurrence and 7 (17.5%) patients developing distant disease, resulting in 3 (7.5%) deaths.

CONCLUSION

Robotic LPLND for rectal cancer can be performed in Western patients to completely resect extra-mesorectal LPLNs and is associated with acceptable perioperative morbidity.

Lateral pelvic lymph node dissection in the management of locally advanced low rectal cancer: Summary of the current evidence

Lateral pelvic lymph nodes (LPLN) are a major site for local recurrence following curative resection for low locally advanced rectal cancer. Ongoing advances in imaging techniques have improved predicting LPLN metastasis (LPLNM) during pre-operative staging. However, there is ongoing debate on optimal management of this subgroup of patients with variation between guidance of different societies. In Japan, LPLNM is considered as local disease and addressed by lateral pelvic node dissection (LPLND) in addition to total mesorectal excision (TME). However, in the west, LPLNM is considered as metastatic disease and those patients are offered neoadjuvant chemoradiotherapy (nCRT) followed by TME surgery. The potential surgical risks and morbidity associated with LPLND as well as the uncertainty of the oncological outcome have raised the concern that patients with locally advanced low rectal cancer with LPLNM could be over or under-treated. A comprehensive review of literature was performed, summarizing the current evidence on available modalities for predicting LPLNM, the role of LPLND in the management of advanced low rectal cancer and the available surgical approaches with their impact on surgical and oncological outcomes. LPLND is associated with increased operative time, blood loss and post-operative morbidity. The potential benefits for local disease control and survival still awaits high quality studies. There has been increasing number of reports of the use minimally invasive approaches in LPLND in an attempt to reduce post-operative complications. There is need for high quality evidence to define the role of LPLND in management of patients with advanced low rectal cancer.

Short-term outcomes of robotic-assisted laparoscopic versus laparoscopic lateral lymph node dissection for advanced lower rectal cancer

BACKGROUND

Therapeutic strategies to suppress local recurrence, including lateral lymph node metastasis, are important to improve the curability of rectal cancer. The aim of the present study was to clarify the advantages of robotic-assisted laparoscopic lateral lymph node dissection (RALLD), comparing its short-term outcomes with those of laparoscopic lateral lymph node dissection (LLLD). There are some retrospective reports comparing RALLD or LLLD and open lateral lymph node dissection (OLLD), but few reports comparing RALLD and LLND to each other.

METHODS

From November 2014 to August 2020, we compared the short-term outcomes in 40 patients who underwent RALLD and 55 patients who underwent LLLD.

RESULTS

The total operative time was significantly longer in the RALLD group than in the LLLD group (p < 0.001). However, lateral dissection time was not significantly different between the groups (p = 0.661). The postoperative hospital time was shorter in the RALLD group than in the LLLD group (p < 0.048). No significant differences were identified in the rates of postoperative bleeding, incisional surgical site infection (SSI), organ/space SSI, urinary disfunction, urinary infection, or small bowel obstruction between the groups. However, anastomotic leakage was significantly lower in the RALLD group than in the LLLD group (p = 0.031).

CONCLUSIONS

The short-term outcomes of RALLD indicate it is feasible, and RALLD may be a useful modality for lower rectal cancer.

Postoperative morbidity and mortality after mesorectal excision with laparoscopic versus conventional open lateral lymph node dissection for advanced rectal cancer: A meta-analysis

Lateral lymph node dissection (LLND) is a challenging procedure due to its technical difficulty and higher incidence of surgical morbidity, thus the purpose of this study is to compare the postoperative morbidity and mortality between laparoscopic and conventional open LLND after mesorectal excision (ME) for advanced rectal cancer. A comprehensive search was conducted in August 2019 based on data from PubMed, Embase, Cochrane Library, CNKI and Wanfang Data to identify relevant studies, and studies comparing laparoscopic with conventional open LLND were included. Seven studies with 335 cases in the laparoscopic LLND group and 841 cases in the conventional open LLND group were finally included. Compared with the conventional open LLND group, the laparoscopic LLND group enjoys a lower postoperative morbidity (OR = 0.47,95% CI [0.23, 0.97], P = 0.04), same postoperative mortality (Postoperative mortality in both groups was zero), shorter length of postoperative hospitalization (WMD = -5.30, 95% CI [-8.42, -2.18], P = 0.0009), less wound infection (OR = 0.40,95% CI [0.21, 0.77], P = 0.006), less intestinal obstruction (OR = 0.50,95% CI [0.29, 0.84], P = 0.009), and less urinary retention (OR = 0.61,95% CI [0.38, 0.97], P = 0.04). There were no significant differences in the incidence of anastomotic leakage, abdominal pelvic abscess and urinary tract infection between the two groups (P > 0.05). But in the sensitivity analysis, there was a significant change of urinary tract infection (OR = 0.22, 95%CI [0.06, 0.89], P = 0.03), and the degree of between-study heterogeneity decreased greatly. In conclusion, laparoscopic LLND may be a better alternative to conventional open LLND for advanced rectal cancer with lower postoperative morbidity and shorter postoperative hospital stay.