Safety, quality and effect of complete mesocolic excision vs non-complete mesocolic excision in patients with colon cancer: a systemic review and meta-analysis

Inter-rater and intra-rater reliability of multi-slice CT and three-dimensional reconstructed imaging analysis of mesenteric vascular anatomy for planning and performing complete mesocolic excision

AIM

Complete mesocolic excision (CME) for colon cancer has been associated with improved oncological outcomes but requires a detailed understanding of complex mesenteric vasculature. Three-dimensional (3D) reconstructed models derived from patient imaging could enhance preoperative anatomical comprehension, enabling safer, precision CME.

METHODS

In this two-phase, blinded, crossover study, four expert CME surgeons evaluated mesenteric vascular anatomy on CT scans and 3D models. In phase 1, surgeons assessed 66 cases, while 20 were re-evaluated in phase 2. The primary outcome measure was inter-rater reliability by Fleiss's kappa. Secondary outcomes were intra-rater reliability by Cohen's kappa and anatomical accuracy rates measured as a percentage of correct responses on a standardised questionnaire.

RESULTS

In phase 1, inter-rater agreement was higher for 3D models (average kappa 0.6, moderate agreement) than for CT scans (average kappa 0.1, poor agreement). Ileocolic vein drainage and ileocolic artery trajectory showed the highest kappa values with 3D imaging (0.85 and 0.93, respectively). Accuracy was also superior with 3D across all surgeons (mean 89.7% correct) versus CT (mean 79.1% correct, P < 0.001). In phase 2, intra-rater reliability remained higher for 3D (average Cohen's kappa 0.61) than CT scans (Cohen's kappa 0.27).

CONCLUSION

3D mesenteric models significantly improve inter- and intra-rater reliability among CME experts over traditional CT scans while markedly enhancing anatomical comprehension accuracy about critical right-sided colonic vasculature. 3D planning could facilitate CME by enabling superior preoperative visualisation of these vessels.

European multicentre analysis of the implementation of robotic complete mesocolic excision for right-sided colon tumours

AIM

Complete mesocolic excision (CME) is an oncologically driven technique for treating right colon cancer. While laparoscopic CME is technically demanding and has been associated with more complications, the robotic approach might reduce morbidity. The aim of this study was to assess the safety of stepwise implementation of robotic CME.

METHOD

A multicentre retrospective analysis of prospectively collected data on robotic right colectomy was performed at five European tertiary centres. Patients were classified for type of surgery: R-RHC (standard right colectomy), R-impCME (learning cases towards robotic CME defined as R-RHC with one but not all the hallmarks of CME) or R-CME (robotic CME). Primary outcomes were overall and severe 30-day complication rates before and after propensity score matching (PSM) analysis.

RESULTS

Five hundred and fifty-one consecutive patients undergoing robotic surgery for (pre)malignant lesions of the right colon between 2010 and 2020 were included: R-RHC (n = 101), R-impCME (n = 135) and R-CME (n = 315). Baseline characteristics differed for American Society of Anesthesiologists score (p = 0.0012) and preoperative diagnosis of adenocarcinoma (p < 0.001). Procedure time increased by surgical complexity (p < 0.001). Vascular event rates did not differ, with no superior mesenteric vein injuries. Conversion, complication and anastomotic leak rates, time to flatus/soft diet and length of stay (LOS) did not differ. While R-RHC was performed for a lower rate of malignancies (p < 0.001), lymph node yield was significantly higher in R-CME (p < 0.001). After PSM, analyses on 186 patients documented no differences in overall and severe 30-day complication rate, conversion rate, LOS or 30-day mortality.

CONCLUSION

R-CME can be implemented without increasing the overall or 30-day severe complication rate.

Comparison between laparoscopic complete mesocolic excision and D2 radical operation in colon carcinoma resection: A propensity score matching analysis

BACKGROUND

Surgery remains the most effective treatment for colon cancer. However, there are still controversies regarding the tumor treatment effect, prognosis, and perioperative impact of complete mesocolic excision (CME) surgery in colon carcinoma resection.

OBJECTIVE

This study aims to compare laparoscopic complete mesocolic excision (LCME) and traditional open D2 radical surgery in colon carcinoma resection through a retrospective analysis using 1:1 propensity score matching (PSM).

METHODS

98 cases undergoing LCME or open D2 colon carcinoma resection at our hospital from January 2014 to November 2021 were retrospectively collected. After excluding cases and 1:1 matching using PSM based on baseline clinical data, 86 patients were assigned in research queue. 43 patients were in each group. Two groups were compared for general clinical baseline indicators. Surgical results and postoperative adverse events of patients were also compared. Disease-free survival (DFS) rate and overall survival (OS) rate was analyzed.

RESULTS

After 1:1 PSM matching, there was no statistically significant differences in baseline data between the LCME group and D2 group (P> 0.05). LCME was characterized by longer total duration of surgery (P< 0.001), less intraoperative bleeding volume (P< 0.001), more postoperative drainage fluid volume (P< 0.001), greater number of lymph nodes retrieved (P= 0.014). No statistically differences was observed regarding intraoperative blood transfusion, hospital stay, Clavien-Dindo complicating disease classification (all P> 0.05), 1 and 3-year DFS rate (P= 0.84) and OS rate (P⩾ 0.1).

CONCLUSION

LCME had a longer duration of surgery but less intraoperative bleeding volume and more postoperative drainage fluid volume and retrieved lymph nodes compared to D2 radical surgery. LCME surgery is comparable to D2 surgery in terms of postoperative prognosis, but LCME surgery shows a positive trend in the overall survival curve.

Optimal extent of lymph node dissection in clinical early-stage right colon cancer: a retrospective analysis

Purpose

Determining the extent of radical lymphadenectomy at clinical early stage is challenging. We aimed to investigate the appropriate extent of lymphadenectomy in clinical early-stage right colon cancer.

Methods

Patients with clinical stage 0 or I right colon cancer who underwent curative surgery from January 2007 to December 2021 were included in this retrospective study. The extent of lymph node (LN) metastases based on the distribution of LN metastases (LND: LND1 pericolic nodes, LND2 intermediate nodes, LND3 apical nodes), along with the depth of submucosal (SM) invasion (classed into SM1-3), were analyzed.

Results

Of the 348 patients, distribution across pathologic stages was as follows: 30 patients (8.6%) at stage 0, 207 (59.5%) at stage I, 52 (14.9%) at stage II, and 59 (17.0%) at stage III. In pT1 tumor patients, LN metastases varied by SM invasion depth: 3.6% in SM1 (all LND1), 5.1% in SM2 (all LND1), and 17.5% in SM3 (LND1 10%, LND2 5%, LND3 2.5%). For pT2, pT3, and pT4 stages, LN metastasis rates were 16.2% (LND1 11.3%, LND2 3.8%, LND3 1.3%), 39.7% (LND1 28.9%, LND2 8.4%, LND3 2.4%), and 50% (LND1 25%, LND2 25%), respectively. Tumor invasion depth and lymphovascular invasion were identified as significant risk factors for LN metastasis extending to LND2-3.

Conclusion

Complete mesocolic excision should be considered for right-sided colon cancer because tumor infiltration deeper than SM2 could metastasize to LND2 or further. If preoperative endoscopy confirms SM1 or SM2 invasion, D2 lymphadenectomy could be a limited surgical option.

Innovative pancreas-guided technique for splenic flexure mobilization in laparoscopic left hemicolectomy

OBJECTIVE

Splenic flexure mobilization (SFM) is a major challenge in laparoscopic left hemicolectomy. This study aims to assess the safety and effectiveness of the pancreas-guided SFM technique during laparoscopic left hemicolectomy.

METHODS

From January 2018 to December 2023, 352 patients with left-sided colon cancer underwent laparoscopic left hemicolectomy. Based on the SFM method used, the patients were divided into the pancreas-guided group (167 cases) or the "Three Approaches Roundabout"/classic group (185 cases). Clinicopathologic characteristics and intraoperative and postoperative variables were compared between the two groups.

RESULTS

The two groups had no significant differences in baseline indicators (P > 0.05). All surgeries were successful without needing to convert to laparotomy, and there were no combined organ resections involving the spleen or pancreas in either group. The mean duration of surgery was significantly lower in the pancreas-guided group than in the classic group (P < 0.01). The median volume of intraoperative blood loss in the pancreas-guided group was lower than that in the classic group (P < 0.01). Through video playback, it was found that the retro-pancreatic space had been entered during operation in 8 cases (4.3%) in the classic group, while there were no such occurrences in the pancreas-guided group. This difference was statistically significant (P < 0.05). The difference in the number of lymph nodes cleared, postoperative hospital stays, and incidence of complications were not statistically significant (all P > 0.05) between the groups.

CONCLUSION

The pancreas-guided SFM technique is a safe and feasible option for laparoscopic left hemicolectomy. Our study's findings suggest that this approach facilitates accurate access to the correct anatomic plane, potentially improving surgical efficiency.

Comparison of Postoperative Outcomes and Long-Term Survival Rates between Patients Who Underwent Robotic and Laparoscopic Complete Mesocolic Excision for Right-Sided Colon Cancer

Introduction: Right colon cancer often requires surgical intervention, and complete mesocolic excision (CME) has emerged as a standard procedure. The study aims to evaluate and compare the safety and efficacy of robotic and laparoscopic CME for patients with right colon cancer and 5-year survival rates examined to determine the outcomes. Materials and Methods: Patients who underwent CME for right-sided colon cancer between 2014 and 2021 were included in this study. Group differences of age, body mass index, operation time, bleeding amount, total harvested lymph nodes, and postoperative stay were analyzed by the Mann-Whitney U test. Group differences of sex, American Society of Anesthesiology, and tumor, node, and metastasis stage were analyzed by the Chi-squared test. Disease-free and overall survival were assessed using Kaplan-Meier curves with the log-rank Mantel-Cox test. Results: From 109 patients, 74 of them were 1:1 propensity score matched and used for analysis. Total harvested lymph node (P ≤ .001) and estimated blood loss (P = .031) were found to be statistically significant between the groups. We found no statistically significant difference between the groups in terms of disease-free and overall survival (P = .27, .86, respectively), and the mortality rate was 9.17%, with no deaths directly attributed to the surgery. Conclusions: Study shows that minimally invasive surgery is a feasible option for CME in right colon cancers, with acceptable overall survival rates. Although the robotic approach has a higher lymph node yield, there was no significant difference in survival rates. Further randomized trials are needed to determine the clinical significance of both approaches.

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.

Robotic versus laparoscopic right colectomy for nonmetastatic pT4 colon cancer: A European multicentre propensity score-matched analysis

AIM

Minimally invasive surgery has been increasingly adopted for locally advanced colon cancer. However, evidence comparing robotic (RRC) versus laparoscopic right colectomy (LRC) for nonmetastatic pT4 cancers is lacking.

METHODS

This was a multicentre propensity score-matched (PSM) study of a cohort of consecutive patients with pT4 right colon cancer treated with RRC or LRC. The two surgical approaches were compared in terms of R0, number of lymph nodes harvested, intra- and postoperative complication rates, overall (OS), and disease-free survival (DFS).

RESULTS

Among a total of 200 patients, 39 RRC were compared with 78 PS-matched LRC patients. The R0 rate was similar between RRC and LRC (92.3% vs. 96.2%, respectively; p = 0.399), as was the odds of retrieving 12 or more lymph nodes (97.4% vs. 96.2%; p = 1). No significant difference was noted for the mean operating time (192.9 min vs. 198.3 min; p = 0.750). However, RRC was associated with fewer conversions to laparotomy (5.1% vs. 20.5%; p = 0.032), less blood loss (36.9 vs. 95.2 mL; p < 0.0001), fewer postoperative complications (17.9% vs. 41%; p = 0.013), a shorter time to flatus (2 vs. 2.8 days; p = 0.009), and a shorter hospital stay (6.4 vs. 9.5 days; p < 0.0001) compared with LRC. These results were confirmed even when converted procedures were excluded from the analysis. The 1-, 3- and 5-year OS (p = 0.757) and DFS (p = 0.321) did not significantly differ between RRC and LRC.

CONCLUSION

Adequate oncological outcomes are observed for RRC and LRC performed for pT4 right colon cancer. However, RRC is associated with lower conversion rates and improved short-term postoperative outcomes.

Innovative perfused cadaveric model for complete mesocolic excision

A high-fidelity cadaver-based training scenario for right colectomy with complete mesocolic excision is presented (Video 1). A feasible perfusion strategy that allows a near-to-reality experience is demonstrated.

Quality assessment of surgery for colorectal cancer: Where do we stand?

Quality assurance in surgery has been one of the most important topics of debate among colorectal surgeons in the past decade. It has produced new surgical standards that led in part to the impressive oncological outcomes we see in many units today. Total mesorectal excision, complete mesocolic excision (CME), and the Japanese D3 lymphadenectomy are now benchmark techniques embraced by many surgeons and widely recommended by surgical societies. However, there are still ongoing discrepancies in outcomes largely based on surgeon performance. This is one of the main reasons why many countries have shifted colorectal cancer surgery only to high volume centers. Defining markers of surgical quality is thus a perquisite to ensure that standards and oncological outcomes are met at an institutional level. With the evolution of CME surgery, various quality markers have been described, mostly based on measurements on the surgical specimen and lymph node yield, while others have proposed radiological markers (i.e. arterial stumps) measured on postoperative scans as part of the routine cancer follow-up. There is no ideal marker; however, taken together and assembled into a new score or set of criteria may become a future point of reference for reporting outcomes of colorectal cancer surgery in research studies and defining subspecialization requirements both at an individual and hospital level.

Complete mesocolic excision and extended lymphadenectomy: Where should we stand?

Debate regarding the risks and merits of complete mesocolic excision and extended lymphadenectomy is ongoing, particularly for right-sided colon cancers. In this article, we hope to provide a succinct yet encompassing review of the relevant literature. We posit that complete mesocolic excision with D3 dissection is indicated in select patients with colon cancers, particularly those distal to the cecum.

A surgical training system designed to help trainees acquire laparoscopic surgical skills at a rural Japanese institute

PURPOSE

The Endoscopic Surgical Skill Qualification System was established in Japan to evaluate safe endoscopic surgical techniques and teaching skills. Trainee surgeons obtaining this certification in rural hospitals are disadvantaged by the limited number of surgical opportunities. To address this problem, we established a surgical training system to educate trainee surgeons.

METHODS

Eighteen certified expert surgeons affiliated with our department were classified into an experienced training system group (E group, n = 9) and a non-experienced group (NE group, n = 9). Results of the training system were then compared between the groups.

RESULTS

The number of years required to become board certified was shorter in the E group (14 years) than that in the NE group (18 years). Likewise, the number of surgical procedures performed before certification was lower in the E group (n = 30) than that in the NE group (n = 50). An expert surgeon was involved in the creation of the certification video of all the E group participants. A questionnaire to board-certified surgeons revealed that guidance by a board-certified surgeon and trainee education (surgical training system) was useful for obtaining certification.

CONCLUSIONS

Continuous surgical training, starting with trainee surgeons, appears useful for expediting their acquisition of technical certification in rural areas.

Factors Affecting the Efficiency of Near-Infrared Indocyanine Green (NIR/ICG) in Lymphatic Mapping for Colorectal Cancer: A Systematic Review

As laparoscopy gained global popularity in oncologic surgery, the challenge of detecting lymph nodes spurred researchers to explore innovative techniques and approach the situation from a fresh perspective. While many proposed methods have faded into obscurity, the utilization of indocyanine green (ICG) in the surgical treatment of oncologic patients has continued to advance. The immense potential of this dye is widely acknowledged, yet its full extent and limitations in lymphatic mapping for colorectal cancer remain to be precisely determined. This article aims to assess the magnitude of its potential and explore the constraints based on insights from clinical studies published by pioneering researchers. A systematic review of the existing literature, comprising articles in English, was conducted using the Scopus, PubMed, and Springer Link databases. The search employed keywords such as "colorectal cancer" AND/OR "indocyanine green," "fluorescence" AND/OR "lymphatic mapping" AND/OR "lymph nodes." Initially identifying 129 articles, the application of selection criteria narrowed down the pool to 10 articles, which served as the primary sources of data for our review. Despite the absence of a standardized protocol for the application of ICG in colorectal cancer, particularly in the context of lymphatic mapping, the detection rates have exhibited considerable variation across studies. Nevertheless, all authors unanimously regarded this technique as beneficial and promising. Additionally, it is advocated as an adjunctive tool to enhance the accuracy of cancer staging. Near-infrared (NIR)-enhanced surgery holds the promise of transforming the landscape of oncologic surgery, emerging as a valuable tool for surgeons. However, the absence of a standardized technique and the subjective nature of result assessment impose limitations on the potential of this method. Consequently, it can be inferred that the establishment of a universally accepted protocol, encompassing parameters such as dose, concentration, technique, and site of administration of ICG, along with the optimal time needed for fluorescence visualization, would enhance the outcomes. Emphasizing the accurate selection of patients is crucial to prevent the occurrence of false-negative results.

[D2 and D3 lymph node dissection for colon cancer]

OBJECTIVE

To evaluate surgical and oncological results of standard and extended lymph node dissection (D2 and D3) in patients with colon cancer.

MATERIAL AND METHODS

We analyzed treatment outcomes in 74 patients with colon cancer stage T1-4aN0-2M0 who underwent right- and left-sided hemicolectomy, resection of sigmoid colon with standard and extended lymph node dissection (D2 and D3).

RESULTS

Surgical approach and level of D3 lymph node dissection did not increase intra- and postoperative morbidity. Laparoscopic interventions were followed by significantly lower intraoperative blood loss and earlier gas discharge. Metastatic lesion of apical lymph nodes was observed in 5 out of 36 patients who underwent D3 lymph node dissection (13.8%), and metastases in regional lymph nodes rN1-2 were found in all these patients. Overall 5-year survival was 86%. Disease-free and overall 5-year survival were similar after D2 and D3 lymph node dissection.

CONCLUSION

D3 lymph node dissection is safe for colon cancer. Metastatic lesions of apical lymph nodes during D3 lymph node dissection were detected only in patients with lesions of regional lymph nodes (rN1-2). Disease-free and overall 5-year survival were similar after D2 and D3 lymph node dissection.

Complete mesocolic excision versus standard resection for colon cancer: a systematic review and meta-analysis of perioperative safety and an evaluation of the use of a robotic approach

PURPOSE

Complete mesocolic excision (CME) has been associated with improved oncological outcomes in treatment of colon cancer. However, widespread adoption is limited partly because of the technical complexity and perceived risks of the approach. The aim of out study was to evaluate the safety of CME compared to standard resection and to compare robotic versus laparoscopic approaches.

METHODS

Two parallel searches were undertaken in MEDLINE, Embase and Web of Science databases 12 December 2021. The first was to evaluate IDEAL stage 3 evidence to compare complication rates as a surrogate marker of perioperative safety between CME and standard resection. The second independent search compared lymph node yield and survival outcomes between minimally invasive approaches.

RESULTS

There were four randomized control trials (n = 1422) comparing CME to standard resection, and three studies comparing laparoscopic (n = 164) to robotic (n = 161) approaches. Compared to standard resection, CME was associated with a reduction in Clavien-Dindo grade 3 or higher complication rates (3.56% vs. 7.24%, p = 0.002), reduced blood loss (113.1 ml vs. 137.6 ml, p < 0.0001) and greater mean lymph node harvest (25.6 vs. 20.9 nodes, p = 0.001). Between the robotic and laparoscopic groups, there were no significant differences in complication rates, blood loss, lymph node yield, 5-year disease-free survival (OR 1.05, p = 0.87) and overall survival (OR 0.83, p = 0.54).

CONCLUSIONS

Our study demonstrated improved safety with CME. There was no difference in safety or survival outcomes between robotic and laparoscopic CME. The advantage of a robotic approach may lie in the reduced learning curve and an increased penetration of minimally invasive approach to CME. Further studies are required to explore this.

PROSPERO ID

CRD42021287065.

Impact of imaging magnification on colorectal surgery: a matched analysis of a single tertiary center

BACKGROUND

Laparoscopy has been increasingly applied in colorectal surgery, and imaging systems have been improving concurrently. The present study aims to compare outcomes following colorectal surgery with the 4K and traditional high-definition (HD) video systems.

METHODS

All consecutive patients undergoing laparoscopic colorectal surgery between April 2016 and June 2020 were retrospectively retrieved from a prospective institutional database. The study population was matched according to the imaging system (4K versus HD groups) through a propensity score matching (PSM) based on perioperative characteristics of 15 patients. A stratified analysis according to surgical procedures (right, left colectomy, and low anterior resection) was also performed. Primary endpoints were intraoperative blood loss and perioperative transfusions. Also, intra- and postoperative morbidity, operative time, lymph node harvest, and length of hospital stay (LOS) were investigated as secondary outcomes.

RESULTS

After PSM, 225 patients were included in both 4K and HD groups. The intraoperative blood loss was significantly lower in the 4K group (p = 0.008), although no different volumes of blood transfusion were required. Postoperative complications presented in similar proportions, while significantly higher rates of abdominal collection (p = 0.045), reoperation (p = 0.005), and postoperative urinary disorders occurred in the HD group. After stratification, the right colectomy subgroup shared similar associations with the study population. LOS did not change between groups, although readmissions were significantly lower in the 4K group (p < 0.001).

CONCLUSIONS

The 4K imaging system represents a technological advance providing better surgical outcomes, such as the minimization of intraoperative blood loss and postoperative morbidity.

Extended Right-Sided Colon Resection Does Not Reduce the Risk of Colon Cancer Local-Regional Recurrence: Nationwide Population-Based Study From Danish Colorectal Cancer Group Database

BACKGROUND

It is controversial whether extensive resection of right-sided colon cancer confers oncological benefits.

OBJECTIVE

The aim of this study was to evaluate short- and long-term outcomes of extended surgical removal of the mesocolon compared to the conventional approach.

DESIGN

This was a retrospective population-based study.

SETTING

Study is based on a prospectively maintained Danish Colorectal Cancer Group database.

MAIN OUTCOME MEASURES

Primary outcome measures included local-regional recurrence in patients who underwent curative resection for right-sided colon cancer and 30-day postoperative complications. Distant metastasis, unplanned intraoperative adverse events, and 30- and 90-day postoperative mortality were also investigated. Patients who had palliative or compromised resection, emergency surgery, or neoadjuvant chemotherapy were excluded.

RESULTS

Of the 12,855 patients with resection of right-sided colon cancer retrieved, 1151 underwent extended right hemicolectomy. Patients who had extended right hemicolectomy were younger males with lower ASA scores, were operated on by colorectal surgeons using a laparoscopic approach, and had a significantly higher number of harvested lymph nodes. The rate of local-regional recurrence was 1.1% (136/12,855), with no difference between conventional right hemicolectomy and extended right hemicolectomy (OR, 1.7; 95% CI, 0.63-2.18). Postoperative medical complications were significantly higher in extended right hemicolectomy even after adjusting for age, comorbidity, access to the abdomen, and other covariates (OR, 1.26; 95% CI, 1.01-1.58). No significant difference was noticed between conventional right hemicolectomy and extended right hemicolectomy in the rates of distant metastasis, unplanned intraoperative adverse events, and mortality.

LIMITATIONS

Because it is a register-based study, underreporting cannot be excluded. Extended right hemicolectomy, as defined in this study, does not reflect the extent of lymphatic dissection performed during the surgery.

CONCLUSIONS

This large population-based register study showed no difference in local-regional recurrence of right-sided colon cancer between conventional and extended right hemicolectomy with mesenteric resection and ligation of the middle colic vessels. Extended resection was associated with higher rates of postoperative complications. See Video Abstract at http://links.lww.com/DCR/B907 .

LA RESECCIN AMPLIADA DEL COLON DERECHO NO REDUCE EL RIESGO DE RECURRENCIA LOCALREGIONAL DEL CNCER DE COLON ESTUDIO POBLACIONAL A NIVEL NACIONAL DE LA BASE DE DATOS DEL GRUPO DANS DE CNCER COLORRECTAL

ANTECEDENTES:Es aun un tema controversial si la resección ampliada del cáncer de colon del lado derecho confiere beneficios oncológicos.OBJETIVOS:El objetivo de este estudio fue examinar los resultados a corto y largo plazo de la resección quirúrgica ampliada del mesocolon en comparación con el enfoque convencional.DISEÑO:Este fue un estudio poblacional de tipo retrospectivo basado en una base de datos del Grupo Danés de Cáncer Colorrectal mantenida de manera prospectiva.AJUSTES:La medida de resultado primaria fue la recurrencia local-regional en pacientes sometidos a resección curativa por cáncer de colon del lado derecho y las medidas de resultado secundarias fueron las complicaciones posoperatorias a los 30 días. También fueron investigadas las metástasis a distancia, los eventos adversos intraoperatorios no planificados y la mortalidad posoperatoria a los 30 y 90 días. Se excluyeron los pacientes sometidos a resección paliativa o comprometida, cirugía de urgencia y quimioterapia neoadyuvante.RESULTADOS:De los 12.855 pacientes recuperados y sometidos a resección de cáncer de colon del lado derecho, 1151 fueron sometidos a hemicolectomía derecha ampliada. Los pacientes sometidos a hemicolectomía derecha ampliada fueron varones más jóvenes con puntuaciones ASA más bajas, operados por cirujanos colorrectales, utilizando la vía laparoscópica, y tuvieron un número significativamente mayor de ganglios linfáticos extraídos. La tasa de recidiva local-regional fue del 1,1% (136 / 12.855) sin diferencia entre la hemicolectomía derecha convencional y la hemicolectomía derecha ampliada (OR 1,7 IC 95% 0,63-2,18). Las complicaciones médicas post operatorias fueron significativamente mayores en la hemicolectomía derecha ampliada incluso después del ajuste por edad, comorbilidad, acceso al abdomen y otras covariables (OR 1,26; IC 95% 1,01-1,58). No se observaron diferencias significativas entre la hemicolectomía derecha convencional y la hemicolectomía derecha ampliada con respecto a las tasas de metástasis a distancia, eventos adversos intraoperatorios no planificados y mortalidad.LIMITACIONES:Es un estudio basado en registros, por lo tanto, no se puede excluir la sub notificación. La hemicolectomía derecha ampliada como se define en este estudio no refleja la extensión de la disección linfática realizada durante la cirugía.CONCLUSIONES:Este gran estudio basado en el registro poblacional no mostró diferencias en la recurrencia local-regional del cáncer de colon del lado derecho entre la hemicolectomía derecha convencional y ampliada con resección mesentérica y ligadura de los vasos cólicos medios. La resección ampliada se asoció con tasas más altas de complicaciones posoperatorias. Consulte Video Resumen en http://links.lww.com/DCR/B907 . (Traducción-Dr. Osvaldo Gauto ).

Should Laparoscopic Complete Mesocolic Excision Be Offered to Elderly Patients to Treat Right-Sided Colon Cancer?

BACKGROUND

Despite its potential oncologic benefit, complete mesocolic excision (CME) has rarely been offered to elderly patients. The present study evaluated the effect of age on postoperative outcomes among patients undergoing laparoscopic right colectomies with CME for right-sided colon cancer (RCC).

METHODS

Data of patients undergoing laparoscopic right colectomies with CME for RCC between 2015 and 2018 were retrospectively analyzed. Selected patients were divided into two groups: the under-80 group and the over-80 group. Surgical, pathological, and oncological outcomes among the groups were compared.

RESULTS

A total of 130 patients were selected (95 in the under-80 group and 35 in the over-80 group). No difference was found between the groups in terms of postoperative outcomes, except for median length of stay and adjuvant chemotherapy received, which were in favor of the under-80 group (5 vs. 8 days, p < 0.001 and 26.3% vs. 2.9%, p = 0.003, respectively). No difference between the groups was found regarding overall survival and disease free survival. Using multivariate analysis, only the ASA score > 2 (p = 0.01) was an independent predictor of overall complications.

CONCLUSIONS

laparoscopic right colectomy with CME for RCC was safely performed in elderly patients ensuring similar oncological outcomes compared to younger patients.

Optimal bowel resection margin in colon cancer surgery: prospective multicentre cohort study with lymph node and feeding artery mapping

Background

There are no standardised criteria for the 'regional' pericolic node in colon cancer, which represents a major cause of the international uncertainty regarding the optimal bowel resection margin. This study aimed to determine 'regional' pericolic nodes based on prospective lymph node (LN) mapping.

Methods

According to preplanned in vivo measurements of the bowel, the anatomical distributions of the feeding artery and LNs were determined in 2996 stages I-III colon cancer patients who underwent colectomy with resection margin >10 cm at 25 institutions in Japan.

Findings

The mean number of retrieved pericolic nodes was 20.9 (standard deviation, 10.8) per patient. In all patients except seven (0.2%), the primary feeding artery was distributed within 10 cm of the primary tumour. The metastatic pericolic node most distant from the primary tumour was within 3 cm in 837 patients, 3-5 cm in 130 patients, 5-7 cm in 39 patients and 7-10 cm in 34 patients. Only four patients (0.1%) had pericolic lymphatic spread beyond 10 cm; all of whom had T3/4 tumours accompanying extensive mesenteric lymphatic spread. The location of metastatic pericolic node did not differ by the feeding artery's distribution. Postoperatively, none of the 2996 patients developed recurrence in the remaining pericolic nodes.

Interpretation

The pericolic nodes designated as 'regional' were those located within 10 cm of the primary tumours, which should be fully considered when determining the bowel resection margin, even in the era of complete mesocolic excision.

Funding

Japanese Society for Cancer of the Colon and Rectum.

The mesocolic apical fragment in complete mesocolic excision colectomies: Should it be analysed separately? A proof-of-concept study

AIM

The aim of this work is to describe a protocol and assess the feasibility of harvesting and analysing the mesocolic apical fragment (MAF) for the presence of central lymph node (LN) metastasis and extra lymphatic free tumour cells in a random subgroup extracted from a cohort of complete mesocolic excision colectomies with central vascular ligation.

METHOD

Forty-seven patients diagnosed with colorectal cancer were included. A 2/2 cm pyramid of tissue was cut around the central tie and sent for pathological examination. The MAF was sectioned into 16 slices. High-definition images were taken from the slices which were merged into a panoramic three-dimensional image of the MAF. The distribution of LNs in the MAF was quantified. Immunohistochemistry staining for cytokeratin 14 was used to identify isolated tumour cells and micrometastases in the extranodal tissue.

RESULTS

No tumoural cells migrating through the apical zone, outside of the LNs, were identified. Margins of resection, mesocolic tissue and LNs were all negative in the subgroup of ultrastaged MAFs. The number of examined central LNs varied between 0 and 24, with positive MAF LNs being identified only in pN2 stages. The rate of positive apical LNs in our cohort was 4.2% (n = 2).

CONCLUSIONS

The MAF can be easily extracted from standard specimens, allowing for accurate analysis of lymphatic and extra-nodal tumour cells on the central resection margins, in central LNs and in the apical mesocolic tissue. Future research on larger cohorts is required to establish if analysing the MAF has an impact on patient staging, prognosis and management.

Relationship between prognostic impact of N3 lymph node metastasis at the root of the feeding artery and location of colon cancer

PURPOSE

To determine whether N3 nodal involvement predicts outcomes and whether its prognostic implications vary with tumor location in patients with Stage III colon cancer (CC).

METHODS

We defined N3 as lymph node metastases near the bases of the major feeding arteries. We retrospectively examined recurrence rates and patterns by tumor location and sites of lymph node metastases in 57 patients with N3 CC who had undergone curative resections between January 2000 and March 2019. Survival analysis was performed to compare the prognoses of patients with and without N3 lymph node metastasis.

RESULTS

Most N3 patients had large tumors (T ≥ 3); five had T2 disease. Recurrence occurred quickly in one patient with T2N3M0 disease. Multivariate survival analysis demonstrated that N3 lymph node metastasis is an independent predictor of poor prognosis in Stage III CC patients (P < 0.001). Categorizing N3 patients according to UICC-TNM staging system does not stratify risk of recurrence (P = 0.970). To investigate the impact of tumor location on recurrence risk, we classified N3 CC into two subtypes according to tumor location: metastasis at the base of the superior mesenteric artery in right-sided CC and inferior mesenteric artery in left-sided CC. The former was found to have a statistically significant poorer prognosis than the latter (P = 0.091).

CONCLUSION

N3 is a robust prognostic marker in CC patients. Recurrence risk varies by tumor location. N3 right-sided CCs with lymph node metastasis at the base of the superior mesenteric artery have poorer prognoses than do N3 left-sided CCs.

Role of preoperative CT angiography with multimodality imaging reconstruction to perform laparoscopic Complete Mesocolic Excision (CME) and Central Vascular Ligation (CVL) in right-sided colon cancer: Is it really useful? A prospective clinical study

BACKGROUND

The concept of complete mesocolic excision (CME) and central vascular ligation (CVL) in right colonic resections appears to improve the oncological outcomes. The highest rate of complications reported in the literature in patients undergoing CME is related to difficult surgical manuevers and intraoperative bleeding due to the central vascular dissection.

METHODS

We used preoperative findings obtained with the CT angiography, multiplanar reformation (MPR), maximum intesity projection (MIP) and 3D volume rendering (VR) technique to verify if this preoperative radiological assessment had significant benefits regarding the difficulty of dissection of the embryological planes, the identification of vascular structures and central lymph nodes with reduction in mean operative time, intraoperative complications and better short-term outcomes versus standard contrast enhanced CT scan. We also have administered a questionnaire to investigate the subjective responses on the degree of difficulty of the surgical procedure both by the surgical team expert in CME and by a group of young surgeons.

RESULTS

Statistical analysis showed that overall operative time was significant shorter in patients underwent to radiological assessment (224,5 min; range 160-300 versus 252,6 min; range 200-340; p-value 0.023) with a significant lower rate of intraoperative complication (2.7% versus 4.2%; p-value 0.043). No differences were reported with respect to blood loss, conversion rate, anastomotic leakage or other surgical results. Analysis of the questionnaire underlined a progressive awareness of the correspondence between the radiological imaging and the surgical field.

CONCLUSION

The possibility of identifying the characteristics and course of the vascular structures along the axis of the superior mesenteric vessels certainly increases the surgeon's knowledge of the operating field, making him more confident with surgical maneuvers and significantly reducing the duration of the operating time and intraoperative complications.

Robotic CME in obese patients: advantage of robotic ultrasound scan for vascular dissection

Complete mesocolic excision (CME) in right-sided colon cancers appears to confer oncological benefits compared to conventional colectomy. Identification of the superior mesenteric vein (SMV) remains challenging. We describe the novel use of intra-operative robotic ultrasound scan (rUSS) in obese patients (BMI ≥ 29). All consecutive patients having robotic CME for colon cancer between 2014 and 2017 were included in this retrospective cohort study. Data were recorded on an ethics approved prospective database and included patient demographics, clinical and oncological outcomes. Patients were divided into group 1 (BMI ≤ 28) and group 2 (BMI ≥ 29). SMV first approach was employed in all cases and SMV detection was aided using rUSS in group 2. Primary outcome was postoperative morbidity. Secondary outcomes included conversion rate, operative time and length of stay (LOS). 41 (group 1, median 66 years) were compared to 32 patients (group 2, median 63 years). There were no conversions to laparoscopy or laparotomy. Median operative times for group 2 were 30 min longer (186 vs. 216 min, p = 0.05). Overall morbidity was similar (20% vs. 19% in group 1 and 2, p = 0.26). There was no significant difference between the two groups with regard to LOS (median 7 vs. 6 days, p = 0.48), readmissions (2 vs. 5, p = 0.13), R0 resection rate (98% vs. 94%, p = 0.43) and lymph node harvest (median 31 vs. 30, p = 0.28).CME can be technically more challenging than conventional colectomy in obese patients and is associated with longer operative times. The use of rUSS in obese patients can help to identify SMV and allow safer dissection.

A Clinicopathological Feature-Based Nomogram for Predicting the Likelihood of D3 Lymph Node Metastasis in Right-Sided Colon Cancer Patients

BACKGROUND

Despite advancements in treating right-sided colon cancer patients, the ideal scope of lymphadenectomy remains controversial.

OBJECTIVE

Our objective was to investigate the likelihood of D3 lymph node metastasis in right-sided colon cancer patients and develop a clinicopathological feature-based nomogram for D3 lymphadenectomy.

DESIGN

We retrospectively analyzed 286 right-sided colon cancer patients who underwent D3 lymphadenectomy. The patients were divided into 2 groups based on whether D3 lymph node metastasis was positive. Then, univariable and multivariable logistic regression analyses were performed to obtain independent risk factors for predicting D3 lymph node metastasis. Moreover, we performed receiver operating characteristic curve analyses to evaluate the predictive power of the model.

SETTING

This study was conducted at Nanfang Hospital of Southern Medical University in China.

PATIENTS

A total of 286 consecutive patients who underwent right hemicolectomy and D3 lymphadenectomy as a primary treatment for right-sided colon cancer between January 2016 and December 2019 were enrolled in this study.

MAIN OUTCOME MEASURES

The primary measures were independent risk factors for predicting D3 lymph node metastasis in right-sided colon cancer.

RESULTS

The D3 lymph node metastasis rate in right-sided colon cancer patients was 16.1% (46/286). D3 lymphadenectasis on CT, lymphatic invasion, and T4 tumors were filtered out as independent risk factors for D3 lymph node metastasis according to the multivariable logistic regression analysis. We established a nomogram that predicted D3 lymph node metastasis of right-sided colon cancer on the combination of the 3 factors with an area under the curve of 0.717 (95% CI, 0.629-0.806).

LIMITATIONS

This was a retrospective study from a single center.

CONCLUSIONS

We developed a valuable clinicopathological feature-based nomogram to predict the incidence of D3 lymph node metastasis in right-sided colon cancer patients. Patients with D3 lymphadenectasis on CT, preoperative T4 tumors, and lymphatic invasion should undergo D3 lymphadenectomy. See Video Abstract at http://links.lww.com/DCR/B852 .

UN NOMOGRAMA BASADO EN CARACTERSTICAS CLNICOPATOLGICAS PARA PREDECIR LA PROBABILIDAD DE METSTASIS EN GANGLIOS LINFTICOS D EN PACIENTES CON CNCER DE COLON DERECHO

ANTECEDENTES:A pesar de los avances en el tratamiento de pacientes con cáncer de colon derecho, el ámbito ideal de la linfadenectomía sigue siendo controvertido.OBJETIVO:Investigar la probabilidad de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho y desarrollar un nomograma basado en características clínico-patológicas basado para la linfadenectomía D3.DISEÑO:Analizamos retrospectivamente a 286 pacientes con cáncer de colon derecho que se sometieron a linfadenectomía D3. Los pacientes se dividieron en dos grupos en función de si eran positivos para metástasis en los ganglios linfáticos D3. Luego, se realizaron análisis de regresión logística univariable y multivariable para obtener factores de riesgo independientes para predecir metástasis en los ganglios linfáticos D3. Además, realizamos análisis de las curvas de características operatorias del receptor para evaluar el poder predictivo del modelo.SEDE:Este estudio se realizó en el Hospital Nanfang de la Universidad Médica del Sur en China.PACIENTES:Un total de 286 pacientes consecutivos que se sometieron a hemicolectomía derecha y linfadenectomía D3 como tratamiento primario para el cáncer de colon derecho entre enero de 2016 y diciembre de 2019 se inscribieron en este estudio.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas primarias fueron factores de riesgo independientes para predecir las metástasis en ganglios linfáticos D3 en el cáncer de colon derecho.RESULTADOS:La tasa de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon del lado derecho fue del 16,1% (46/286). El aumento de tamaño de ganglios D3 en la TC, la invasión linfática y los tumores T4 se filtraron como factores de riesgo independientes de metástasis en los ganglios linfáticos D3 de acuerdo con el análisis de regresión logística multivariable. Establecimos un nomograma que predijo metástasis en los ganglios linfáticos D3 del cáncer de colon derecho en la combinación de los tres factores con un área bajo la curva de 0,717 (IC del 95%, 0,629-0,806).LIMITACIONES:Este fue un estudio retrospectivo de un solo centro.CONCLUSIONES:Desarrollamos un valioso nomograma basado en características clínico-patológicas para predecir la incidencia de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho. Los pacientes con crecimiento de ganglios D3 en TC, tumores con clasificación preoperatoria T4 e invasión linfática, deben ser sometidos a linfadenectomía D3. Consulte Video Resumen en http://links.lww.com/DCR/B852 . (Traducción-Dr. Juan Carlos Reyes ).

Computer-Assisted Differentiation between Colon-Mesocolon and Retroperitoneum Using Hyperspectral Imaging (HSI) Technology

Complete mesocolic excision (CME), which involves the adequate resection of the tumor-bearing colonic segment with "en bloc" removal of its mesocolon along embryological fascial planes is associated with superior oncological outcomes. However, CME presents a higher complication rate compared to non-CME resections due to a higher risk of vascular injury. Hyperspectral imaging (HSI) is a contrast-free optical imaging technology, which facilitates the quantitative imaging of physiological tissue parameters and the visualization of anatomical structures. This study evaluates the accuracy of HSI combined with deep learning (DL) to differentiate the colon and its mesenteric tissue from retroperitoneal tissue. In an animal study including 20 pig models, intraoperative hyperspectral images of the sigmoid colon, sigmoid mesentery, and retroperitoneum were recorded. A convolutional neural network (CNN) was trained to distinguish the two tissue classes using HSI data, validated with a leave-one-out cross-validation process. The overall recognition sensitivity of the tissues to be preserved (retroperitoneum) and the tissues to be resected (colon and mesentery) was 79.0 ± 21.0% and 86.0 ± 16.0%, respectively. Automatic classification based on HSI and CNNs is a promising tool to automatically, non-invasively, and objectively differentiate the colon and its mesentery from retroperitoneal tissue.

Qualitative umbrella review of systematic reviews on complete mesocolic excision for colon cancer

BACKGROUND

Complete mesocolic excision (CME) of colon cancer with extended lymphadenectomy was suggested to improve radical resection of colon cancer. This comprehensive review aimed to assess the current literature for the outcomes of CME of colon cancer through an appraisal of the findings of published systematic reviews and meta-analyses.

METHODS

A systematic literature review searching for the studies that assessed the outcome of CME of colon cancer was conducted. Electronic databases were queried from 2009 through November 2020. The main objectives of this review were to illustrate the technical aspects and outcome of CME and to summarize the findings of the published systematic reviews.

RESULTS

Thirteen systematic reviews were retrieved. All reviews found CME to provide longer bowel, larger area of mesentery resected, and more lymph nodes (LNs) retrieved than standard colectomy. All systematic reviews except two found similar complication rates between CME and standard colectomy. Four systematic reviews documented the survival benefit of CME in regards to improved overall and disease-free survival. Using the laparoscopic approach for CME did not compromise the oncologic outcomes of the procedures, yet was associated with less intraoperative blood loss, faster recovery, and potential survival benefits.

CONCLUSIONS

CME is associated with better specimen quality, more LNs clearance, and potential survival benefits compared to standard colectomy. However, the lack of robust data from well-designed multicenter randomized trials may prevent drawing firm conclusions on the oncologic benefits of CME. Further high-quality studies are needed before recommending CME as the standard of care for colon cancer.

Pattern of recurrence and survival after D2 right colectomy for cancer: is there place for a routine more extended lymphadenectomy?

BACKGROUND

Conventional Right Colectomy with D2 lymphadenectomy (RC-D2) currently represent the most common surgical treatment of right-sided colon cancer (RCC). However, whether it should be still considered a standard of care, or replaced by a routine more extended D3 lymphadenectomy remains unclear. In the present study, we aim to critically review the patterns of relapse and the survival outcomes obtained from our 11-year experience of RC-D2.

METHODS

Clinical data of 489 patients who underwent RC-D2 for RCC at two centres, from January 2009 to January 2020, were retrospectively reviewed. Patients with synchronous distant metastases and/or widespread nodal involvement at diagnosis were excluded. Post-operative clinical-pathological characteristics and survival outcomes were evaluated including the pattern of disease relapse.

RESULTS

We enrolled a total of 400 patients with information follow-up. Postoperative morbidity was 14%. The median follow-up was 62 months. Cancer recurrence was observed in 55 patients (13.8%). Among them, 40 patients (72.7%) developed systemic metastases, and lymph-node involvement was found in 7 cases (12.8%). None developed isolated central lymph-node metastasis (CLM), in the D3 site. The estimated 3- and 5-year relapse-free survival were 86.1% and 84.4%, respectively. The estimated 3- and 5-year cancer-specific OS were 94.5% and 92.2%, respectively.

CONCLUSIONS

The absence of isolated CLM, as well as the cancer-specific OS reported in our series, support the routine use of RC-D2 for RCC. However, D3 lymphadenectomy may be recommended in selected patients, such as those with pre-operatively known CLM, or with lymph-node metastases close to the origin of the ileocolic vessels.

Consensus statements on complete mesocolic excision for right-sided colon cancer-technical steps and training implications

Background

CME is a radical resection for colon cancer, but the procedure is technically demanding with significant variation in its practice. A standardised approach to the optimal technique and training is, therefore, desirable to minimise technical hazards and facilitate safe dissemination. The aim is to develop an expert consensus on the optimal technique for Complete Mesocolic Excision (CME) for right-sided and transverse colon cancer to guide safe implementation and training pathways.

Methods

Guidance was developed following a modified Delphi process to draw consensus from 55 international experts in CME and surgical education representing 18 countries. Domain topics were formulated and subdivided into questions pertinent to different aspects of CME practice. A three-round Delphi voting on 25 statements based on the specific questions and 70% agreement was considered as consensus.

Results

Twenty-three recommendations for CME procedure were agreed on, describing the technique and optimal training pathway. CME is recommended as the standard of care resection for locally advanced colon cancer. The essential components are central vascular ligation, exposure of the superior mesenteric vein and excision of an intact mesocolon. Key anatomical landmarks to perform a safe CME dissection include identification of the ileocolic pedicle, superior mesenteric vein and root of the mesocolon. A proficiency-based multimodal training curriculum for CME was proposed including a formal proctorship programme.

Conclusions

Consensus on standardisation of technique and training framework for complete mesocolic excision was agreed upon by a panel of experts to guide current practice and provide a quality control framework for future studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08395-0.

Multidimensional evaluation of the learning curve for laparoscopic complete mesocolic excision for right colon cancer: a risk-adjusted cumulative summation analysis

AIM

Despite the suggested potential benefit of complete mesocolic excision (CME) for right-sided colon cancer (RCC) for patient survival, concerns about its safety and feasibility have contributed to delayed acceptance of the procedure, especially when performed by a minimally invasive approach. Thus, the aim of this work was to evaluate the actual learning curve (LC) of laparoscopic CME for experienced colorectal surgeons.

METHOD

Prospectively collected data for consecutive patients undergoing laparoscopic CME for RCC between October 2015 and January 2021 at our institution, operated on by experienced surgeons, were analysed. A multidimensional assessment of the LC was performed through cumulative sum (CUSUM) and risk-adjusted (RA) CUSUM analysis.

RESULTS

Two hundred and two patients operated by on by three surgeons were considered. The CUSUM graphs based on operating time showed one peak of the curve between 17 and 27 cases. The CUSUM graphs based on surgical failure showed one peak of the curve between 20 and 24 cases The RA-CUSUM curve also showed one preeminent peak at 24-33 cases. Based on the CUSUM and RA-CUSUM analyses all the surgeons reached proficiency in 24-33 cases.

CONCLUSIONS

Our study showed that an experienced minimally invasive colorectal surgeon acquires proficiency in laparoscopic CME for RCC after performing 24-33 cases.

Does cranial-medial mixed dominant approach have a unique advantage for laparoscopic right hemicolectomy with complete mesocolic excision?

BACKGROUND

Complete mesocolic excision (CME) with central vascular ligation (CVL) was proposed by Hohenberger in 2009. The CME principle has gradually become the technical standard for colon cancer surgery. How to achieve CME with CVL in laparoscopic right hemicolectomy (LRH) is controversial, and a unified standard approach is not yet available. In recent years, the authors’ team has integrated the theory of membrane anatomy, tried to combine the cephalic approach with the classic medial approach (MA) for technical optimization, and proposed a cranial-medial mixed dominant approach (CMA).

AIM

To explore the feasibility of operational approaches for LRH with CME.

METHODS

In this retrospective cohort study, the clinical data of 57 patients with right-sided colon cancer (TNM stage I, II, or III) who underwent LRH with CME from January 2016 to June 2020 were collected and summarized. There were 31 patients in the traditional MA group and 26 in the CMA group.

RESULTS

There were no significant differences in baseline data between the two groups. The operation was shorter and the number of lymph nodes dissected was higher in the CMA group than in the MA group, but there was no significant difference in the number of positive lymph nodes, intraoperative blood loss, postoperative exhaust time, feeding time, postoperative hospital stay or postoperative complication incidence.

CONCLUSION

Our study shows that the CMA is a safe and feasible procedure for LRH with CME and has a unique advantage.

D2 lymphadenectomy with complete mesogastrium excision vs. conventional D2 gastrectomy for advanced gastric cancer

Background:

The complete mesogastrium excision (CME) based on D2 radical gastrectomy is believed to significantly reduce the local-regional recurrence compared with D2 radical gastrectomy in advanced gastric cancer, and it is widely used in China. This study aimed to explore whether D2 + CME is superior to D2 on surgical outcomes during gastrectomy from Chinese data.

Methods:

Feasible studies comparing the D2 + CME (D2 + CME group) and D2 (D2 group) published up to March 2020 are searched from electronic databases. The data showing surgical and complication outcomes are extracted to be pooled and analyzed.

Results:

Fourteen records including 1352 patients were included. The D2 + CME group had a shorter mean operative time (weighted mean difference [WMD] = —16.72 min, 95% confidence interval [CI]: −26.56 to −6.87 min, P < 0.001), lower mean blood loss (WMD = −39.08 mL, 95% CI: −49.94 to −28.21 mL, P < 0.001), higher mean number of retrieved lymph nodes (WMD = 2.13, 95% CI: 0.58–3.67, P = 0.007), shorter time to first flatus (WMD = −0.31 d, 95% CI: −0.53 to − 0.10 d, P = 0.005), and postoperative hospital days (WMD = −1.09, 95% CI: −1.92 to −0.25, P = 0.010) than the D2 group. Subgroup analysis suggested that the advantages from the D2 + CME group were obvious in traditional open radical gastrectomy, proximal gastrectomy, and distal gastrectomy compared with D2 group. The evaluations of post-operative complications showed that the patients who underwent D2 + CME had a lower incidence of post-operative complications than the patients who underwent D2 surgery alone (relative risk [RR] = 0.65, 95% CI: 0.45–0.87, P = 0.003). The D2 radical gastrectomy plus CME improved 3-year overall survival (OS) (RR = 1.16, 95% CI: 1.02–1.32, P = 0.020) and lowered the local recurrence rate (RR = 0.51, 95% CI: 0.28–0.94, P = 0.030). The patients undergoing laparoscopic surgery or total gastrectomy had more significant advantages compared between D2 + CME and D2 groups in 3-year OS.

Conclusion:

The data from China show that D2 radical gastrectomy plus CME are reliable procedures and safety compared to D2 radical gastrectomy with faster recovery, lower risk, and better prognosis.

Postoperative Quality Assessment Score Can Select Patients with High Risk for Locoregional Recurrence in Colon Cancer

BACKGROUND

Monitoring surgical quality has been shown to reduce locoregional recurrence (LRR). We previously showed that the arterial stump length (ASL) after complete mesocolic excision (CME) is a reproducible quality instrument and correlates with the lymph-node (LN) yield. We hypothesized that generating an LRR prediction score by integrating the ASL would predict the risk of LRR after suboptimal surgery.

METHODS

502 patients with curative resections for stage I-III colon cancer were divided in two groups (CME vs. non-CME) and compared in terms of surgical data, ASL-derived parameters, pathological parameters, LRR and LRR-free survival. A prediction score was generated to stratify patients at high risk for LRR.

RESULTS

The ASL showed significantly higher values (50.77 mm ± 28.5 mm) with LRR vs. (45.59 mm ± 28.1 mm) without LRR (p < 0.001). Kaplan-Meier survival analysis showed a significant increase in LRR-free survival at 5.58 years when CME was performed (Group A: 81%), in contrast to non-CME surgery (Group B: 67.2%).

CONCLUSIONS

The prediction score placed 76.6% of patients with LRR in the high-risk category, with a strong predictive value. Patients with long vascular stumps and positive nodes could benefit from second surgery to complete the mesocolic excision.

Infrapyloric and gastroepiploic node dissection for hepatic flexure and transverse colon cancer: A systematic review

INTRODUCTION

The hepatic flexure and transverse colon have a complex intermingled lymphovascular anatomy crossing between mesocolon and mesogastrium. Few studies have investigated the oncological relevance of metastatic infrapyloric and gastroepiploic lymph nodes (IGLN) from hepatic flexure and transverse colon tumors. This study aimed to evaluate the incidence and risk factors for IGLN metastases, and the indications, surgical morbidities, and oncological outcome following extended lymphadenectomy.

MATERIALS AND METHODS

According to the PRISMA statement, a systematic review on IGLN lymphadenectomy for colon cancer was conducted into PubMed, Embase, and Cochrane databases. A critical appraisal of study was performed according to the Joanna Briggs Institute Tools.

RESULTS

Nine studies were included. IGLN metastases incidence ranged 0.7-22%. IGLN positivity for patients with metastatic mesocolic lymph nodes ranged 1.7-33.3%. Postoperative complication rate ranged 8.5-36.9%, mostly low grade according to Clavien-Dindo's classification. Postoperative mortality rate ranged 0-5.4% at 30-days. IGLN metastases were associated with advanced disease with a 5-year progression-free survival rate up to 33.9%. Two authors reported perineural invasion and N stage as risk factors, while another reported endoscopic obstruction, signet ring adenocarcinoma, CEA level ≥17 ng/ml, and M1 stage to be risk factors for IGLN involvement. Apart from one study, all other studies were of moderate/high quality.

CONCLUSIONS

Metastatic IGLNs are not uncommon and should be highly considered. IGLN metastases could be potentially associated with an aggressive disease. IGLN dissection is not associated with higher morbidity and mortality than standard CME. Preoperative risk factors of IGLN involvement could guide surgical indication for extended lymphadenectomy.

Disease recurrence after right hemicolectomy in Scotland: Is there rationale to adopt complete mesocolic excision (CME)?

AIMS

Complete mesocolic excision (CME) has been proposed as a way to improve the oncological outcomes in patients with colon cancer. To investigate whether there is rationale for adopting the technique in Scotland, our aim was to define the incidence of disease recurrence following standard right hemicolectomy and to compare this with published CME outcomes.

METHODS

Data was collected on consecutive patients undergoing right or extended right hemicolectomy for colonic adenocarcinoma (2012-2017) at three hospitals in Scotland (Raigmore Hospital, Aberdeen Royal Infirmary and Glasgow Royal Infirmary). Emergency or palliative surgery was excluded. Patients were followed up with CT scans and colonoscopy for a minimum of 3 years.

RESULTS

689 patients (M 340, F 349) were included. 30-day mortality was 1.6%. Final pathological stage was Stage I (14%), Stage II (49.8%) and Stage III (36.1%). During follow-up, 10.5% developed loco-regional recurrence and 12.2% developed distant metastases. The 1, 3 and 5-year disease-free survival (DFS) was 94%, 84% and 82% respectively. Primary determinants of recurrence were T stage (p < 0.001), N stage (p < 0.001), apical node involvement (p < 0.001) and EMVI (p < 0.001). When compared to the literature, 30-day mortality was lower than many published series and DFS rates were similar to the largest CME study to date (4 year DFS 85.8% versus 83%).

CONCLUSION

The outcomes of patients undergoing right hemicolectomy in Scotland compare favourably with many published CME studies. The technique demands further evaluation before it can be recommended for adoption into routine surgical practice.

Early salvage total mesorectal excision (sTME) after organ preservation failure in rectal cancer does not worsen postoperative outcomes compared to primary TME: systematic review and meta-analysis

IMPORTANCE

While oncological outcomes of early salvage total mesorectal excision (sTME) after local excision (LE) have been well studied, the impact of LE before TME on postoperative outcomes remains unclear. We aimed to compare early sTME with a primary TME for rectal cancer.

METHODS

Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines with the random-effects model were adopted using Review Manager Version 5.3 for pooled estimates.

RESULTS

We retrieved eleven relevant articles including 1728 patients (350 patients in the sTME group and 1438 patients in the TME group). There was no significant difference between the two groups in terms of mortality (OR = 0.90, 95%CI [0.21 to 3.77], p = 0.88), morbidity (OR = 1.19, 95%CI [0.59 to 2.38], p = 0.63), conversion to open surgery (OR = 1.34, 95%CI [0.61 to 2.94], p = 0.47), anastomotic leak (OR = 1.38, 95%CI [0.50 to 3.83], p = 0.53), hospital stay (MD = 0.23 day, 95%CI [- 1.63 to 2.10], p < 0.81), diverting stoma rate (OR = 0.69, 95%CI [0.44 to 1.09], p = 0.11), abdominoperineal resection rate (OR = 1.47, 95%CI [0.91 to 2.37], p = 0.11), local recurrence (OR = 0.94, 95%CI [0.44 to 2.04], p = 0.88), and distant recurrence (OR = 0.88, 95%CI [0.52 to 1.48], p = 0.62). sTME was associated with significantly longer operative time (MD = 25.62 min, 95%CI[11.92 to 39.32], p < 0.001) lower number of harvested lymph nodes (MD =  - 2.25 lymph node, 95%CI [- 3.86 to - 0.65], p = 0.006), and higher proportion of incomplete TME (OR = 0.25, 95%CI [0.11 to 0.61], p = 0.002).

CONCLUSIONS

sTME is not associated with increased postoperative morbidity, mortality, or local recurrence. However, the operative times are longer and yield a poor specimen quality.

Oncological and clinical outcomes after conventional right hemicolectomy

PURPOSE

Complete mesocolic excision (CME) has been proposed for better local control of colon cancer and to improve cancer-specific survival (CSS). However, CME may be associated with increased morbidity from bleeding during central vascular ligation. This study aimed to investigate the outcome of conventional right hemicolectomy, a traditional anatomical dissection along anatomical planes with radical excision of the central lymph nodes at the level of the origin of colic artery but without exposure of superior mesenteric vein and artery (SMV/SMA).

METHOD

This was a retrospective review of a cohort of all elective right hemicolectomies performed at a specialist tertiary unit during a five-year period (2011-2015).

RESULTS

Five-hundred-nineteen patients (271 female, a median age of 73.0 years (interquartile range (IQR) 65.0-80.0)) were included (Stage I disease: 2.7%, stage II: 53.2%, stage III: 33.3%, stage IV: 10.8%). At the latest follow-up (a median 47 months (IQR 29-67)), local recurrence occurred in 34 patients (6.6%). Three-year overall survival was 74.4% and 3-year CSS was 85.9%. Subgroup analysis for stage I-III showed local recurrence in 6.0%, sole distant recurrence in 7.6% while 19 patients (4.1%) suffered concomitant local and distant recurrence. The anastomotic leak rate was 1.0% and perioperative bleeding occurred in 1.2%.

CONCLUSIONS

Oncological outcomes comparable to those of CME can be achieved by conventional surgery but with low rates of bleeding complications and anastomotic leakage. The proposed advantages of CME should be carefully considered and balanced against patients' co-morbidities and potential complications.

Right-side colectomy with complete mesocolic excision vs conventional right-side colectomy in the treatment of colon cancer: a systematic review and meta-analysis

BACKGROUND

This meta-analysis aims to investigate the role of complete mesocolic excision (CME) in the treatment of right-side colon cancer when compared with standard right-side hemicolectomy, focusing on oncological outcomes, mortality and morbidity rates.

MATERIALS AND METHODS

A systematic literature search was performed on MEDLINE and EMBASE archives, including studies on CME in right-side colon cancer. Primary outcomes were five-year disease-free survival and five-year overall survival. Secondary outcomes investigated were mortality and morbidity rates, intraoperative blood loss, anastomotic leakage, postoperative ileus, day of postoperative flatus, pulmonary infection, duration of hospital stay and number of lymph nodes harvested.

RESULTS

Seventeen studies have been included in this meta-analysis for a total of 3918 patients. The five-year disease-free survival (DFS) and overall survival (OS) results improved in the CME group with respect to conventional right-side colectomy with an OR 1.88 (95% CI 1.02-3.45) and OR 2.77 (95% CI 1.33-5.74), respectively. The incidence of mortality and morbidity was comparable between the two groups. Moreover, conventional surgery time was faster than CME (MD 33.69 min, 95% CI 12.79-54.59), while no significant differences were reported in mean blood loss and hospital stay. Furthermore, the CME group showed a higher mean number of harvested lymph nodes (MD 7.08 lymph nodes 95% CI 4.90-9.27).

CONCLUSION

Complete mesocolic excision of the right-side colectomy improves oncological outcomes without increasing mortality and morbidity rates compared to standard right-side hemicolectomy. CME should therefore be routinely performed in the treatment of right-side colon cancer.