A Systematic Review of Varying Definitions and the Clinical Significance of Fredet's Fascia in the Era of Complete Mesocolic Excision

BACKGROUND

Fredet's fascia represents a crucial landmark for vascular surgical anatomy, especially in minimally invasive complete mesocolic excision (CME) for right-sided colon adenocarcinoma. Fredet's fascia allows access to the gastrocolic trunk of Henle (GCTH), the most critical step in both open and minimally invasive right-sided CME techniques. Despite this, a recent workshop of expert surgeons on the standardization of the laparoscopic right hemicolectomy with CME did not recognize or include the term of Fredet's fascia or area. Hence, we undertook a systematic review of articles that include the terms "Fredet's fascia or area", or synonyms thereof, with special emphasis on the types of articles published, the nationality, and the relevance of this area to surgical treatments.

METHODS

We conducted a systematic review up to 15 July 2022 on PubMed, WOS, SCOPUS, and Google Scholar.

RESULTS

The results of the study revealed that the term "Fredet's fascia" is poorly used in the English language medical literature. In addition, the study found controversial and conflicting data among authors regarding the definition of "Fredet's fascia" and its topographical limits.

CONCLUSIONS

Knowledge of Fredet's fascia's surgical relevance is essential for colorectal surgeons to avoid accidental injuries to the superior mesenteric vascular pedicle during minimally invasive right hemicolectomies with CME. In order to avoid confusion and clarify this fascia for future use, we suggest moving beyond the use of the eponymous term by using a "descriptive term" instead, based on the fascia's anatomic structure. Fredet's fascia could, therefore, be more appropriately renamed "sub-mesocolic pre-duodenopancreatic fascia".

Inflammation in the proximal colon is a risk factor for the development of colorectal neoplasia in inflammatory bowel disease patients with primary sclerosing cholangitis

Background

Patients with primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) have an increased risk of developing colorectal neoplasia (CRN) in the proximal colon.

Objectives

To evaluate whether duration and severity of inflammation are linked to the development of CRN in this population.

Design

Retrospective, case-control chart review of patients with PSC and IBD at a tertiary care center.

Methods

Disease activity was scored per colonic segment at each colonoscopy prior to the first instance of observed CRN using a modified Mayo endoscopic sub-score and histologic assessment. Patients in the CRN-positive group were compared to controls that did not.

Results

In all, 72 PSC-IBD patients with no history of CRN were identified, 13 of whom developed CRN after at least one colonoscopy at our institution. Patients in the CRN-positive group had significantly more endoscopic (p < 0.01) and histologic (p < 0.01) inflammation in the right compared to the control group prior to the development of dysplasia. There was significantly greater endoscopic inflammation in the segment of the colon with a dysplastic lesion than other segments of the colon (p = 0.018). Patients with moderate/severe lifetime endoscopic (p = 0.02) or histologic inflammation (p = 0.04) score had a lower probability of remaining free of dysplasia during follow-up. Nearly half of the patients with dysplasia had invisible lesions found on random biopsy.

Conclusions

Endoscopic and histologic inflammation in the proximal colon are risk factors for CRN in patients with PSC-IBD. PSC-IBD patients frequently have subclinical inflammation, and these findings support the practice of regular assessment of disease activity and random biopsy of inflamed and uninflamed areas in patients with PSC with the goal of reducing inflammation to prevent the development of CRN.

Validation of the German classification system for quality assessment of right-sided colon cancer specimens

AIM

The German classification system of the completeness of mesocolic excision aims to assess the quality of right-sided colonic cancer surgery by review of photographs. We aimed to validate the reliability of the classification in a clinical context.

METHOD

The study was based on a cohort of patients undergoing resection for right-sided colon cancer in two university hospitals served by the same group of pathologists. Prospectively collected photographs of the specimens were assessed twice by six colorectal surgeons to determine the intra-rater and inter-rater accuracy of the German classification and a modification assessing extended right-sided resections.

RESULTS

Specimens from 613 resections for right-sided colon cancer were reviewed. Twenty-one specimens were found to be non-assessable, leaving 436 right hemicolectomies, 139 extended right hemicolectomies and 17 right-sided subtotal colectomies. Intra-rater reliability was 0.57-0.74 and weighted kappa coefficients 0.58-0.74, without differences between subgroups. The percentage of agreement between all six participants was 20.3% for all specimens, 21.1% for right hemicolectomy specimens and 18.1% for extended hemicolectomy and right-sided subtotal colectomy specimens. For the right hemicolectomy specimens, the model-based kappa coefficient for agreement was 0.27 (95% CI 0.24-0.30) and for association 0.45 (95% CI 0.41-0.49).

CONCLUSION

The German classification of right hemicolectomy specimens showed low intra-rater reliability and inter-rater agreement and association. The use of this classification for scientific purposes appeared not to be reliable.

Association between plane of mesocolic dissection and recurrence after complete mesocolic excision for right-sided colon cancer: a cohort study

AIM

Dissection in the mesocolic plane is considered by some medical professionals to be crucial in complete mesocolic excision. We aimed to assess whether intramesocolic plane dissection is associated with a risk of recurrence after complete mesocolic excision for right-sided colon cancer.

METHOD

This is a single-centre study based on prospectively registered data on patients undergoing resection for Union for International Cancer Control Stage I-III right-sided colon adenocarcinoma during the period 2010-2017. Patients were stratified in an intramesocolic plane group or a mesocolic plane group based on a prospective assessment of fresh specimens by a pathologist. Primary outcome was the 4.2 year risk of recurrence after inverse probability treatment weighting and competing risk analyses.

RESULTS

Of 383 patients, 4 (1%) were excluded as the specimen was assessed as muscularis propria plane, 347 (91.6%) specimens were deemed as mesocolic and 32 (8.4%) as intramesocolic. The 4.2 year cumulative incidence of recurrence after inverse probability treatment weighting was 9.1% (95% CI 6.0%-12.1%) in the mesocolic group compared with 14.0% (3.6%-24.5%) in the intramesocolic group with an absolute risk difference in favour of mesocolic plane dissection of 4.9% (-5.7 to 15.6, p = 0.37). No difference was observed in the risk of local recurrence, death before recurrence or overall survival after 4.2 years between the two groups.

CONCLUSION

Mesocolic plane dissection can be achieved in more than 90% of patients. The classification seems to be a guide for good surgical practice and not to be used for research purposes.

Differences Between Right and Left Colon Cancer in Beira Interior

Introduction Colorectal cancer (CRC) is the second most common cancer in Portugal and worldwide, with a high mortality rate, especially in more advanced stages. In recent decades, there has been a growing interest in the distinction between right colorectal carcinoma (RCC) and left colorectal carcinoma (LCC) due to the different presentation, treatment, and prognosis. Studies show that RCC and LCC have different clinical and biological characteristics, being considered two distinct entities. Material and methods This cross-sectional, descriptive, and comparative retrospective study included data collection at the three hospitals of Beira Interior - Centro Hospitalar Cova de Beira, Hospital Amato Lusitano, and Hospital Sousa Martins - over a 6-year period. Results The proportion of RCC cases was higher. The proportion of women was higher in the RCC group compared to the LCC (46.2%, 121/262 vs. 39%, 76/195). Anemia was statistically higher in the RCC group (p <0.01). On the other hand, intestinal occlusion tends to appear in patients with LCC (p <0.001). The most frequent surgery was elective. The proportion of emergency surgery was higher in the LCC group (LCC vs RCC: 27.2% vs 18.3%; p = 0.03). Discussion and conclusion In both the RCC and LCC groups, the male sex is the most frequently observed in Beira Interior and in Portugal, opposite from the world population, in which the female sex predominates in patients with RCC. The RCC presents alterations in bowel habits more often (p> 0.05). On the other hand, anemia is more common in RCC and intestinal occlusion in LCC, following the current literature. Conducting targeted studies and optimizing the screening and treatment processes are key to reducing mortality associated with CRC.

Clinical Factors Associated with Severity of Colonic Diverticular Bleeding and Impact of Bleeding Site

Factors associated with serious colonic diverticular bleeding (CDB) are unclear, although the incidence of CDB has increased. We carried out this study to clarify factors associated with serious CDB and rebleeding. Subjects included 329 consecutive patients hospitalized for confirmed or suspected CDB between 2004 and 2021. Patients were surveyed regarding backgrounds, treatment, and clinical course. Of 152 with confirmed CDB, 112 showed bleeding from the right colon, and 40 did from the left colon. Patients received red blood cell transfusions in 157 (47.7%), interventional radiology in 13 (4.0%), and surgery in 6 (1.8%) cases. Early rebleeding within one month occurred in 75 (22.8%) patients, and late rebleeding within one year occurred in 62 (18.8%). Factors associated with red blood cell transfusion included confirmed CDB, anticoagulants, and high shock index. The only factor related to interventional radiology or surgery was confirmed CDB, which was also associated with early rebleeding. Late rebleeding was associated with hypertension, chronic kidney disease and past CDB. Right CDB showed higher rates of transfusion and invasive treatment than left CDB. Confirmed CDB had high frequencies of transfusion, invasive treatment, and early rebleeding. Right CDB seemed to be a risk for serious disease. Factors related to late rebleeding were different from those related to early rebleeding of CDB.

LATAM Collaborative Colorectal Surgery Consortium. Postoperative outcomes of right hemicolectomy for cancer in 11 countries of Latin America: A multicentre retrospective study

AIM

There is scant evidence regarding surgical outcomes of patients with colon cancer in Latin America. The aim of this work was to compare perioperative (30 day) outcomes of patients undergoing surgery for right colon cancer in Latin America based on centre volume.

METHOD

This is a multi-institutional retrospective cohort study. Individuals operated on for right colon cancer with curative intent in an urgent or elective setting between 2016 and 2021 were eligible for inclusion in the study. Patients were divided into two groups according to whether they were operated on in low-volume or high-volume centres (defined as more than 30 cases/year).

RESULTS

A total of 2676 patients from 46 hospitals in 11 countries of Latin America were included, with 389 (14.5%) in the low-volume group. The median age was 67.37 years. The high-volume group presented higher rates of laparoscopic procedures (56.8 vs. 35.7%, p < 0.001, OR 2.36), with lower conversion rates, fewer intraoperative complications and a shorter operating time. The high-volume group had a shorter length of hospital stay. The overall complication rate for the whole group was 15.9%, with a lower incidence of these events in the high-volume group (13.7 vs. 28.7%, p < 0.001, OR 0.40). Overall, anastomotic leakage, reoperation and mortality rates were 5.6%, 9.2% and 6.1%, respectively, with differences favouring high-volume centres. On multivariate analysis, low-volume group, history of cardiac disease, emergency surgery, operation performed by a general surgeon, open approach and intraoperative complications were independent predictors of major postoperative complications.

CONCLUSION

This is the first study in Latin America to show better postoperative outcomes at a regional scale when surgery for right colon cancer is performed in high-volume centres. Further studies are needed to validate these data and to identify which of the factors can explain the present results.

A Study of the Right Colonic Vascular Anatomy: Correlations between Veins and Arteries

Objectives

Few studies have examined the correlations between the arteries and veins of the right colon. In this study, we aimed to use high-resolution CT scans to understand the vascular anatomy of Henle's gastrocolic trunk and review the terminology describing the arteries and veins of the right colon.

Methods

This retrospective study has examined patients who underwent laparoscopic colectomy for right colon cancer in a single institution in Japan. Scans from consecutive patients who underwent surgery between October 2017 and March 2020 (n = 165) were examined. Preoperative CT images were used to create multiplanar reformation images and volume rendering images.

Results

Among the 139 patients with Henle's gastrocolic trunk (GCT) present, arteries accompanying the accessory right colic vein (ARCV) were most common on the right branch of the middle colic artery (MCA) (71.2%), followed by the right colic artery (RCA) (19.4%); meanwhile, 9.4% of the patients had no accompanying arteries. Of patients with no accompanying arteries to the ARCV, RCA was present in 15.4%. Among the 26 patients with no GCT, the right colic vein (RCV) existed in 15 patients, with the artery accompanying the RCV most commonly being the right branch of the MCA (66.6%), followed by the RCA (33.3%).

Conclusions

Irrespective of the presence of GCT, approximately 70% of the arteries accompanying the drainage vein from the right colon were the right branch of the MCA. We suggest that vascular branch formation be considered preoperatively in surgical management for right colon cancer.

Plasma protein expression differs between colorectal cancer patients depending on primary tumor location

Colorectal cancer (CRC) includes tumors in the right colon, left colon, and rectum, although they differ significantly from each other in aspects such as prognosis and treatment. Few previous mass spectrometry-based studies have analyzed differences in protein expression depending on the tumor location. In this study, we have used mass spectrometry-based proteomics to analyze plasma samples from 83 CRC patients to study if differences in plasma protein expression can be seen depending on primary tumor location (right colon, left colon, or rectum). Differences were studied between the groups both regardless of and according to tumor stage (II or III). Large differences in plasma protein expression were seen, and we found that plasma samples from patients with rectal cancer separated from samples from patients with colon cancer when analyzed by principal component analysis and hierarchical clustering. Samples from patients with cancer in the right and left colon also tended to separate from each other. Pathway analysis discovered canonical pathways involved in lipid metabolism and inflammation to be enriched. This study will help to further define CRC as distinct entities depending on tumor location, as shown by the widespread differences in plasma protein profile and dysregulated pathways.

Colonoscopic withdrawal time and adenoma detection in the right colon

Shorter colonoscopic withdrawal time (CWT) has been associated with lower adenoma detection rate (ADR), which can increase the risk of interval colorectal cancer (ICC) that commonly arises in the right colon (RC). Therefore, a better ADR in the RC could decrease the incidence of ICC. We analyzed the relationship between CWT and ADR in the RC and entire colon.We retrospectively reviewed the patients who had undergone screening colonoscopy at Chungnam National University Hospital between March 2015 and February 2016. We enrolled 5370 patients in whom colonoscopies were performed by 7 gastroenterologists. We categorized patients into 4 groups in the RC and 6 groups in the entire colon by CWT. Multivariable analysis was used for detection of adenoma in the RC and entire colon.In the RC, the odds ratio (OR) of CWT longer than 3 minutes was 3.70, compared to CWT of <2 minutes [3.06-4.85, 95% confidence interval (CI), P < .001]. In the entire colon, the OR of CWT between 9 to 10 minutes and longer than 10 minutes was 3.34 [2.61-4.27, 95% CI, P < .001] and 3.49 [2.80-4.33, 95% CI, P < .001] compared to CWT of <6 minutes.Based on our result, we suggest that the optimum CWT in the RC should exceed 3 minutes, and considering the "ceiling effect," the optimum CWT in the entire colon should exceed 9 minutes.

Characteristics of right-sided colonic neoplasia and colonoscopy barriers limiting their early detection and prognosis: a review of the literature

Colonoscopy provides less protection from colorectal cancer in the right colon than the left. Areas covered: This review examines patient outcomes and colonoscopy success rates to identify factors that limit the protective effect of colonoscopy in the right colon. The MEDLINE and Embase databases were searched for literature from 2000 onwards, on the long-term outcomes and differences in screening practice between the right and left colon. In total, 12 systematic reviews (including nine meta-analyses) and 44 primary data records were included. Differences in patient outcomes and colonoscopy practice were identified between the right and left colon, suggesting that several factors, many of which disproportionally affect the right colon, impact lesion detection rates. Shorter withdrawal times reduce detection rates, while longer times significantly increase detection; mostly of adenomas in the right colon. Colonoscope attachments often only show a significant improvement in detection rates in the right colon, suggesting detection is more challenging due to visibility of the right colonic mucosa. Higher bowel cleansing grades significantly improve detection rates in the right colon compared to the left. Expert commentary: These findings confirm the need for continued improvement of colonoscopy effectiveness, and obligatory quality assessment, overall and especially in the right colon.

Vascular Structures of the Right Colon: Incidence and Variations with Their Clinical Implications

BACKGROUND AND AIMS

There is a demand for a better understanding of the vascular structures around the right colonic area. Although right hemicolectomy with the recent concept of meticulous lymph node dissection is a standardized procedure for malignant diseases among most surgeons, variations in the actual anatomical vascular are not well understood. The aim of the present review was to present a detailed overview of the vascular variation pertinent to the surgery for right colon cancer.

MATERIALS AND METHODS

Medical literature was searched for the articles highlighting the vascular variation relevant to the right colon cancer surgery.

RESULTS

Recently, there have been many detailed studies on applied surgical vascular anatomy based on cadaveric dissections, as well as radiological and intraoperative examinations to overcome misconceptions concerning the arterial supply and venous drainage to the right colon. Ileocolic artery and middle colic artery are consistently present in all patients arising from the superior mesenteric artery. Even though the ileocolic artery passes posterior to the superior mesenteric vein in most of the cases, in some cases courses anterior to the superior mesenteric artery. The right colic artery is inconsistently present ranging from 63% to 10% across different studies. Ileocolic vein and middle colic vein is always present, while the right colic vein is absent in 50% of patients. The gastrocolic trunk of Henle is present in 46%-100% patients across many studies with variation in the tributaries ranging from bipodal to tetrapodal. Commonly, it is found that the right colonic veins, including the right colic vein, middle colic vein, and superior right colic vein, share the confluence forming the gastrocolic trunk of Henle in a highly variable frequency and different forms.

CONCLUSION

Understanding the incidence and variations of the vascular anatomy of right side colon is of crucial importance. Failure to recognize the variation during surgery can result in troublesome bleeding especially during minimal invasive surgery.

Laparoscopic right colectomy: Miles away or just around the corner?

BACKGROUND:

Despite the drive toward centralization of surgery in high-volume centers, the majority of colectomies are still performed by low- or medium-volume surgeons.

MATERIALS AND METHODS:

A modification of the technique of laparoscopic right colectomy (LRC) originally described by Young-Fadok and Nelson was developed. The key points of that technique were maintained, but a different port-site layout and a counterclockwise approach were adopted, to warrant better trocar triangulation, to reduce the need of right colon manipulation and to avoid dissection along false planes. This modified technique was applied in 82 patients by 16 surgeons with no previous experience in LRC.

RESULTS:

Average operative time was 125 ± 35 min. Conversion occurred in 10 cases (12.2%). Grade III postoperative complications occurred in 3 patients (3.6%). No postoperative mortality was observed. Average number of lymph nodes retrieved was 19 ± 6. Average length of stay was 7 ± 4 days.

CONCLUSION:

Providing low-volume surgeons with simplified and easy-to-learn surgical techniques could improve outcomes and lead to an increased use of laparoscopy.

Familial colorectal adenocarcinoma and hereditary nonpolyposis colorectal cancer: a nationwide epidemiological study from Sweden

Although estimates are available of the proportion of hereditary nonpolyposis colorectal cancer (HNPCC) among all colorectal cancer (CRC), its proportion among familial CRC is unclear. We estimated these proportions epidemiologically from the nationwide Swedish Family-Cancer Database on 9.6 million individuals. Colorectal adenocarcinomas were retrieved from the Cancer Registry covering years 1958-1996. Standardized incidence ratios (SIRs) were calculated for offspring (aged less than 62 years) when their parent had colorectal adenocarcinoma. In 9.82% of all families, an offspring and a parent were affected, giving a population attributable proportion of 4.91% and a familial SIR of 2.00. When offspring and parents shared the anatomic site, the SIR was 2.32 for proximal and 2.00 for distal CRC. When offspring were diagnosed before age 40 years and parents before age 50 years, the SIR was 25.72 for familial proximal CRC. In older age groups familial risks did not differ between proximal and distal CRC. Familial risks were increased also for endometrial, small intestinal and gastric cancers, manifestations in HNPCC. Depending on which assumptions were made, HNPCC was calculated to account for 20 to 50% of familial CRC, corresponding to 1 or 2.5% of all CRC among 0-61-year-old individuals.