[Chinese expert consensus on the surgical treatment of right-sided colon cancer (2024 edition)].

In the past two decades, with the development and application of laparoscopic technique and the promotion of the concept of complete mesocolic excision, significant changes have occurred in the surgical treatment of right-sided colon cancer. The Chinese Society of Colorectal Surgery and Chinese Colorectal Research Consortium (CCRC) Organized national experts in colorectal surgery to form a consensus on 14 key clinical issues related to right hemicolectomy, taking into account the preferences of Chinese doctors and patients as well as the pros and cons of intervention measures, with a view to standardizing the surgical treatment of right colon cancer. The consensus recommendations were focused on three main aspects: (1) surgical anatomy: the key structures and its definitions related to the mesentery and vascular anatomy were clarified. It is recommended that the left side of the superior mesenteric artery be considered the medial boundary for complete mesocolic excision; (2) surgical technique: laparoscopy is recommended as the preferred surgical approach for right-sided colon cancer; (3) surgical principles: D2 lymph node dissection could be considered as the standard of care for right-sided colon cancer. Standard D2 could be considered as routine procedure unless preoperative imaging or intraoperative exploration revealed suspected regional lymph node metastasis. Dissection of infrapyloric lymph node is not recommended unless it is suspected as metastasis. Additionally, consensus recommendations were made regarding the location of vascular ligation, the extent of bowel resection, and anastomosis techniques.

[Fascial anatomy of ligamentous structures associated with colon cancer surgery].

The ligamentous structures integral to the surgical management of colon cancer include the gastrocolic ligament, the phrenicocolic ligament, and the splenocolic ligament. Historically, the era of conventional open surgery was characterized by the use of large forceps for clamping and ligating these ligaments. However, the advent of fascial and mesenteric anatomy research has ushered in a paradigm shift. Aided by high-definition laparoscopy, colorectal surgeons have progressively clarified the fundamental anatomical structures, thereby refining surgical techniques in accordance with fascial and mesenteric anatomical principles. This study synthesizes the author's anatomical research findings to dissect the fascial and mesenteric anatomy of the ligaments pertinent to colon cancer surgery, thereby exploring their implications for surgical practice and oncological outcomes. The gastrocolic ligament exhibits distinct fascial and mesenteric anatomical configurations within the omental sac and extra-omental regions. Within the omental sac, the sub-omental arch pathway emerges as a viable alternative to the paracolic approach for accessing the omental sac through the gastrocolic ligament. Conversely, in the extra-omental region, the incision of the greater omentum overlaying the space between the mesogastrium and the transverse mesocolon represents a mesenteric bridge facilitating access to this area. The incidence of nodal metastasis in the gastrocolic ligament associated with transverse colon and hepatic flexure colon cancer is notably low; nevertheless, selective dissection in high-risk patients can still provide survival benefits. The splenocolic ligament is formed by the convergence of the splenic hilum region of the mesogastrium (including the pancreatic mesentery) with the mesocolon of the splenic flexure of the colon. A natural avascular plane exists within it, and dissection along this plane can avoid encountering the branches of the left gastroepiploic artery that are typically encountered in traditional dissection routes. To date, there is no compelling evidence advocating for the resection of the splenic hilum region of the mesogastrium or the lymph nodes of the gastrocolic ligament in the context of splenic flexure colon cancer.

Proposal for standardization of laparoscopic D3 lymphadenectomy for right colon cancer.

BACKGROUND: This study presents a laparoscopic surgical protocol for right hemicolectomy and D3 lymphadenectomy (R-D3L) in right colon cancer and reports the oncological outcomes based on a prospective series. METHODS: The study comprises two phases. In the first phase, a dynamic demonstration of the R-D3L surgical protocol is provided through textual explanation, illustrations, and edited surgical videos. The protocol emphasizes technical steps such as dissection of the embryological plane of the right mesocolon, high tie of ileocolic vessels, surgical trunk of Gillot dissection, and high tie of superior right colic vein (SRCV). In the second phase, a prospective observational study was conducted involving patients undergoing R-D3L surgery with this protocol between July 2015 and July 2021. Demographic, perioperative, and postoperative variables are analyzed, along with anatomopathological variables and oncological outcomes. RESULTS: A total of 33 patients were analyzed. Median operative time was 202 min. Perioperative bleeding occurred in 6%. Postoperative complications were mild (Clavien-Dindo III in 2%). Postoperative ileus was observed in 15%. No anastomotic dehiscence was reported. The median postoperative stay was 7 days. The median number of resected lymph nodes was 26, with 27% having positive nodes and 70% were classified as stage T3 or T4. After a median follow-up of 45 months, local recurrence, distant recurrence, and carcinomatosis rates were 0%. Mortality rate from other causes was 9%. CONCLUSION: The surgical protocol shown in the present study could help in the implementation of this technique in those units that consider it appropriate.

Laparoscopic D3 right hemicolectomy with intracorporeal anastomosis.

Complete mesocolic excision (CME) with D3 lymphadenectomy for colon cancer has been shown to improve overall as well as disease-free survival compared to conventional right hemicolectomy. Performing a laparoscopic CME/D3 right hemicolectomy with intracorporeal anastomosis (ICA) can be technically demanding even for experienced operators. Here, we present a systematic, standardized approach to the surgery.

Learning curve and safety of the implementation of laparoscopic complete mesocolic excision with intracorporeal anastomosis for right-sided colon cancer: results from a propensity score-matched study.

BACKGROUND: Retrospective studies and randomized controlled trials support the safety of laparoscopic complete mesocolic excision (CME) for the treatment of right-sided colon cancer (RSCC). Few studies, however, examine the learning curve of this operation and its impact on safety during an implementation period. We aim to evaluate the learning curve and safety of the implementation of laparoscopic CME with intracorporeal anastomosis for RSCC. METHODS: Consecutive patients undergoing a laparoscopic right colectomy with intracorporeal anastomosis for RSCC between January 2016 and June 2023 were included. Clinical, perioperative, and histopathological variables were collected. Correlation and cumulative sum (CUSUM) analyses between the operating time and case number were performed. Breakpoints of the learning curve were estimated using the broken-line model. CME and conventional laparoscopic right colectomy outcomes were compared after propensity score matching (PSM). RESULTS: Two hundred and ninety patients underwent laparoscopic right colectomy during study period. One hundred and eight met inclusion criteria. After PSM, 56 non-CME and 28 CME patients were compared. CME group had a non-statistically significant tendency to a longer operating time (201 versus 195 min; p = 0.657) and a shorter hospital stay (3 versus 4 days; p = 0.279). No significant differences were found in total complication rates or their profile. Correlation analysis identified a significant trend toward operating time reduction with increasing case numbers (Pearson correlation coefficient = - 0.624; p = 0.001). According to the CUSUM analysis, an institutional learning curve was deemed completed after 13 cases and the broken-line model identified three phases: learning (1-6 cases), consolidation (7-13 cases), and mastery (after 13 cases). CONCLUSION: The learning curve of laparoscopic CME for RSCC can be achieved after 13 cases in centers with experience in advanced laparoscopic surgery and surgeons with familiarity with this technique. Its implementation within this setting seems to be as safe as performing a conventional right colectomy.

Modified Rosi-Cahill technique after left extended colectomy for splenic flexure advanced tumors.

Advanced splenic flexure tumors are uncommon and have a higher risk of relapse. To ensure that the resection includes the entire area of lymphatic drainage with a complete mesocolic excision (CME), a left extended colectomy is needed. In peritoneal carcinomatosis, there is often extensive involvement of the sigma and splenic flexure of the colon. In many instances, total colectomies are chosen for these patients, even when a significant portion of the colon could be preserved. The potential impact on quality of life after splenic flexure colon resection is discussed, as well as the importance of anatomical knowledge and expertise in performing this type of surgery. Overall, this work presents a modified technique that aims to improve the outcomes and quality of life for patients with splenic flexure colon cancer. Creating a tension-free anastomosis after extended left-sided colorectal resection is challenging. There is a negative impact on quality of life when an ileorectal anastomosis is created. The colorectal anastomosis performed after modified Rosi-Cahill or Deloyers' technique allows reduced small bowel bacterial overgrowth, achieves better water and sodium absorption, and altogether permits improved stool consistency. There are potential advantages of the Rosi-Cahill technique over other popular options such as Deloyers' procedure as there is no torsion of the ileocolic vessels and no mesenteric windows. A video was recorded showing a potential pitfall during Deloyers' technique resulting in the creation of a mesenteric window. The proper rotation of the colon during the modified Rosi-Cahill procedure was also filmed. Overall, this work presents a modified technique for reconstruction after left extended colectomy that aims to improve the outcomes and quality of life for patients with splenic flexure colon cancer.

Advanced Preoperative Clinical Stage Is Associated With More Lymph Node Harvest in Patients With Right Colon Cancer.

PURPOSE: The adequacy of lymph node (LN) harvest is important in oncological colon cancer resections. While several studies have suggested factors influencing LN yield in colon cancer, limited data are available only regarding right hemicolectomies with complete mesocolic excision (CME) and central vessel ligation (CVL). METHODS: A retrospective analysis was conducted on 169 patients who underwent right hemicolectomies with CME and CVL for right-sided colon cancer between February 2019 and March 2023. The patients were divided into 2 groups: groups with ≤24 LN yield and >24 LN yield, and the patient, surgical, and pathologic factors, which could potentially influence the LN yield, were analyzed. RESULTS: Younger age, lower American Society of Anesthesiologists (ASA) classification, and advanced clinical TNM (cTNM) stage among patient factors, the presence of obstructions regarding the surgical factors, and the presence of desmoplastic tumor reaction in the pathologic factors were more likely to harvest >24 LNs. In a multivariate analysis, younger age, lower ASA classification, advanced cTNM stage, and an ileocolic artery (ICA) crossing pattern posterior to the superior mesenteric vein (SMV) were independently associated with a >24 LN harvest. Patients with cTNM 3,4 showed the tendency of > 24 LN yield consistently within each subgroup, irrespective of the age, ASA classification, and ileocolic artery crossing pattern. CONCLUSIONS: Our investigation revealed a significant correlation between the advanced preoperative clinical stage and an increased number of harvested lymph nodes (LNs) in patients undergoing right hemicolectomies with CME a CVL. The observed association is potentially influenced by tumor aggressiveness and the extent of surgical resection performed by the surgeon. To elucidate the intricate relationship between surgical outcomes and the quantity of LN harvest in patients subjected to standardized CME and CVL for right-sided colon cancer, further dedicated research is warranted.

Surgical treatment of right-sided colon cancer with complete mesocolic excision.

Complete mesocolic excision for right-sided colon cancer yields larger specimens with higher lymph node harvest. This has caused a reduction in recurrence rates and improved survival. However, the technique remains controversial and has been associated with a higher risk of intraoperative complications. More recently published studies do not indicate that CME is associated with increased postoperative morbidity rates as summarised in this review. More detailed consensus regarding the use of the technique is needed, and future studies should aim for prospective confirmation of the current positive long-term results.

Conventional surgery in colon cancer with comparison to complete mesocolic excision and central vascular ligation: initial experience in a tertiary centre.

INTRODUCTION: The complete mesocolic excision (CME) and central vascular ligation (CVL) is an advanced surgical technique used to treat colon cancer. It combines the removal of the affected portion of the colon and surrounding lymph nodes with an improved method of controlling the vascular supply to the tumour. MATERIALS AND METHODS: A retrospective study of patients with colon cancer underwent right hemicolectomy (either CME and CVL or conventional method) were operated by colorectal surgeons in a tertiary centre in Kuala Lumpur from 2018 to 2020. We review the data to compare the oncological, pathological and surgical outcomes of both techniques. Categorical variables were presented as frequencies and percentages. Continuous variables were compared using an independent t-test or Mann-Whitney Rank U test. The chi-square test was used to determine the association between categorical variables and mortality. Statistical analysis was conducted with IBM SPSS Statistics 25.0, and statistical significance was set at p<0.05. RESULTS: A total of 30 patients (CME and CVL=15 or conventional colectomies=15) were included in this study with mean age of 65 years. There was no statistical difference between the mean age of the two groups (p=0.355). Most of the patients were Malays (46.7%) followed by Chinese (43.3 %) and Indians (10.0%). The mean (SD) = 19 (9) number of lymph nodes harvested is more in CME and CVL groups which however is not statistically significant compared to the mean (SD) = 16 (9), number of lymph nodes in conventional colectomies. The duration of surgery is longer in CME and CVL groups (214 minutes) compared to conventional colectomies (188 minutes) but with no significant statistical difference. Most of the perioperative complications were similar in both groups with no significant statistical differences. CONCLUSION: CME and CVL are not inferior to conventional surgery in colon surgery in a tertiary centre. It should be considered since the advantages such as lymph node yield and median recurrence free survival are better with similar perioperative morbidity.

Colon cancer: feeling the imbalance?

While neoadjuvant chemotherapy has become the standard of care for rectal cancers in most centres, there is much interest in neoadjuvant chemotherapy in colon cancer after the recent publication of the FOxTROT trial. The management of colon cancers seems to be heading down the same path as rectal cancer, where the radicality of surgery is replaced by chemotherapy intensification. The role of demanding procedures such as complete mesocolic excision with central venous ligation in this new paradigm of upfront chemotherapy remains uncertain and uninvestigated.

Surgical quality assessment for the prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for nonmetastatic right colon cancer (PIONEER study).

BACKGROUND: The modified complete mesocolic excision (mCME) procedure for right-sided colon cancer is a tailored approach based on the original complete mesocolic excision (CME) methodology. Limited studies evaluated the safety and feasibility of laparoscopic mCME using objective surgical quality assessments in patients with right colon cancer. The objectives of the PIONEER study were to evaluate oncologic outcomes after laparoscopic mCME and to identify optimal clinically relevant endpoints and values for standardizing laparoscopic right colon cancer surgery based on short-term outcomes of procedures performed by expert laparoscopic surgeons. MATERIALS AND METHODS: This is an ongoing prospective, multi-institutional, single-arm study conducted at five tertiary colorectal cancer centers in South Korea. Study registrants included 250 patients scheduled for laparoscopic mCME with right-sided colon adenocarcinoma (from the appendix to the proximal half of the transverse colon). The primary endpoint was 3-year disease-free survival. Secondary outcomes included 3-year overall survival, incidence of morbidity in the first 4 weeks postoperatively, completeness of mCME, central radicality, and distribution of metastatic lymph nodes. Survival data will be available after the final follow-up date (June 2024). RESULTS: The postoperative complication rate was 12.9%, with a major complication rate of 2.7%. In 87% of patients, central radicality was achieved with dissection at or beyond the level of complete exposure of the superior mesenteric vein. Mesocolic plane resection with an intact mesocolon was achieved in 75.9% of patients, as assessed through photographs. Metastatic lymph node distribution varied by tumor location and extent. Seven optimal clinically relevant endpoints and values were identified based on the analysis of complications in low-risk patients. CONCLUSIONS: Laparoscopic mCME for right-sided colon cancer produced favorable short-term postoperative outcomes. The identified optimal clinically relevant endpoints and values can serve as a reference for evaluating surgical performance of this procedure.

Safety and Efficacy of Hook Diathermy in the Dissection of the Mesocolorectum During Laparoscopic-Assisted Pull-Through for Hirschsprung Disease in Low-Resource Settings.

Background: Surgical correction is the main line of treatment for the congenital disorder Hirschsprung's disease (HD). Laparoscopic techniques proved their safety and efficacy in previous studies. LigaSure™ is the gold standard for colorectal dissection. However, other sealing methods could be used during the unavailability of LigaSure. Purpose: This study aimed to assess the safety profile of the hook diathermy technique compared to LigaSure in colorectal dissection during laparoscopic-assisted pull-through for HD. Materials and Methods: This case-control study was held in the pediatric surgery department at Assiut University Hospitals between September 2017 and January 2023. The study included 57 HD patients who were surgically operated on during a laparoscopic-assisted pull-through. They were divided into 2 groups according to the sealing methods: the ligasure group included 25 patients, and the hook diathermy group included 32 patients. Results: Both groups had no statistically significant differences regarding age, sex, or weight. The transition zone was present in all patients, and most transition zones were rectosigmoid. No cases reported intraoperative blood transfusion or conversion to an open or transanal approach. Minimum intraoperative blood loss was reported in both groups, with no significant differences. As regards postoperative complications, including bleeding, leakage, perianal excoriation, and enterocolitis, no significant differences between both groups were found. Conclusion: The LigaSure and hook diathermy techniques are safe and effective sealing methods for colorectal dissection during laparoscopic-assisted pull-through for HD.