The mesocolon: a prospective observational study

Sigmoid take-off in rectosigmoid cancer as a landmark identifying benefit from neoadjuvant chemoradiation: A retrospective comparative cohort study

INTRODUCTION

There is no standard treatment strategy for rectosigmoid cancer because of the diverse definitions of the proximal rectal origin. This study aimed to evaluate sigmoid take-off compared with other landmarks of the rectosigmoid junction in guiding oncological therapy and outcomes.

MATERIALS AND METHODS

This retrospective, comparative cohort study included patients diagnosed with rectosigmoid carcinoma at our centre between January 2010 and December 2018. The patients were classified into the neoadjuvant treatment group and upfront surgery group. The oncological outcomes were compared between the two groups in relation to the tumor position.

RESULTS

A total of 656 patients (median age 64 years) were included. After propensity score matching, the 3- and 5-year overall survival and disease-free survival in patients in both the groups were comparable. However, when only patients with rectal cancer as defined by the sigmoid take-off point were included, the disease-free survival rate in the upfront surgery group was significantly lower than that in the neoadjuvant treatment group (p = 0.03 in patients who underwent computed tomography, p = 0.03 in patients who underwent magnetic resonance imaging). The turning point of the beneficial hazard ratio of neoadjuvant therapy was compared according to the different definitions of the rectosigmoid junction and the sigmoid take-off was found to be the most effective.

CONCLUSION

The sigmoid take-off point is a suitable landmark for identifying the rectosigmoid junction and is an important defining criterion for assessing the benefit of neoadjuvant therapy. The application of this definition in clinical practice and future trials is warranted.

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".

Macroscopic Evaluation of Colon Cancer Resection Specimens

Colon cancer is a common disease internationally. Outcomes have not improved to the same degree as in rectal cancer, where the focus on total mesorectal excision and pathological feedback has significantly contributed to improved survival and reduced local recurrence. Colon cancer surgery shows significant variation around the world, with differences in mesocolic integrity, height of the vascular ligation and length of the bowel resected. This leads to variation in well-recognised quality measures like lymph node yield. Pathologists are able to assess all of these variables and are ideally placed to provide feedback to surgeons and the wider multidisciplinary team to improve surgical quality over time. With a move towards complete mesocolic excision with central vascular ligation to remove the primary tumour and all mechanisms of spread within an intact package, pathological feedback will be central to improving outcomes for patients with operable colon cancer. This review focusses on the key quality measures and the evidence that underpins them.

The Mesentery-Past, Present, and Future

This article summarizes the events that shaped our current understanding of the mesentery and the abdomen. The story of how this evolved is intriguing at several levels. It speaks to considerable personal commitment on the part of the pioneers involved. It explains how scientific and clinical fields went different directions with respect to anatomy and clinical practice. It demonstrates that it is no longer acceptable to adhere unquestioningly to models of abdominal anatomy and surgery. The article concludes with a brief description of the Mesenteric Model of abdominal anatomy, and of how this now presents an opportunity to unify scientific and clinical approaches to the latter.

Radiology of the Mesentery

The recent description and re-classification of the mesentery as an organ prompted renewed interest in its role in physiological and pathological processes. With an improved understanding of its anatomy, accurately and reliably assessing the mesentery with non-invasive radiological investigation becomes more feasible. Multi-detector computed tomography is the main radiological modality employed to assess the mesentery due to its speed, widespread availability, and diagnostic accuracy. Pathologies affecting the mesentery can be classified as primary or secondary mesenteropathies. Primary mesenteropathies originate in the mesentery and subsequently progress to involve other organ systems (e.g., mesenteric ischemia or mesenteric volvulus). Secondary mesenteropathies describe disease processes that originate elsewhere and progress to involve the mesentery with varying degrees of severity (e.g., lymphoma). The implementation of standardized radiological imaging protocols, nomenclature, and reporting format with regard to the mesentery will be essential in improving the assessment of mesenteric anatomy and various mesenteropathies. In this article, we describe and illustrate the current state of art in respect of the radiological assessment of the mesentery.

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.

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.

Is Laparoscopic Complete Mesocolic Excision and Central Vascular Ligation Really Necessary for All Patients With Right-Sided Colon Cancer?

Colon cancer treatment is on the way to evolution over several decades. The minimally invasive surgery has improved postoperative short-term outcomes. Adjuvant chemotherapy has prolonged the survival of advanced colon cancer patients. Hohenberger proposed the noble concept of complete mesocolic excision (CME) which consists of 3 components: plane surgery, sufficient longitudinal bowel resection, and central vascular ligation (CVL). Mesocolic plane surgery shares the same surgical principle of total mesorectal excision, which is maintaining the intact mesothelial envelope. However, there remain debates about the extent of bowel resection and the level of CVL for maximizing lymph node dissection. There is no solid clinical evidence for the oncological necessity and benefit of extended radical dissection in right hemicolectomy. CME with CVL based on open surgery has been adopted in laparoscopic surgery. So, it is also necessary to look at how the CME could be transformed and successfully implanted in the laparoscopic era. Recent rapid advances in surgical technology and cancer biology are preparing for fundamental changes in cancer surgery. In this study, we reviewed the history, oncological necessity, and compatibility of CME for the right hemicolectomy in the laparoscopic era and outline the new perspectives on the evolution of cancer surgery.

Role of Extended Mesenteric Excision in Postoperative Recurrence of Crohn's Colitis: A Single-Center Study

INTRODUCTION

The mesentery is involved in Crohn's disease. The impact of the extent of mesenteric resection on postoperative disease progression in Crohn's disease remains unconfirmed. This study aimed to determine the association between resection of the mesentery and postoperative outcomes in patients with Crohn's colitis (CC) undergoing colorectal surgery.

METHODS

Patients with CC who underwent colorectal resection between January 2000 and December 2018 were reviewed, and the data were gathered from a prospectively maintained database. Patients were divided into 2 groups according to the extent of mesenteric resection, the extensive mesenteric excision (EME) group and the limited mesenteric excision (LME) group. Outcomes including early postoperative morbidities and surgical recurrence were compared between the 2 groups.

RESULTS

Of the 126 patients included, 60 were in the LME group and 66 in the EME group. There was no significant difference between the 2 groups in early postsurgical outcomes except the intraoperative blood loss was increased in the LME group (P = 0.002). Patients in the EME group had a longer postoperative surgical recurrence-free survival time when compared with those in the LME group (P = 0.01). LME was an independent predictor of postoperative surgical recurrence (hazard ratio 2.67, 95% confidence interval 1.04-6.85, P = 0.04). This was further confirmed in the subgroup analysis of patients undergoing colorectal resection and anastomosis (hazard ratio 2.83, 95% confidence interval 1.01-7.96, P = 0.048).

DISCUSSION

In patients undergoing surgery for CC, inclusion of the mesentery is associated with similar short-term outcomes and improved long-term outcomes compared with those seen when the mesentery is retained.

The Sphincter of O'Beirne - Part 1: Study of 18 Normal Subjects

BACKGROUND

Gastroenterologists have ignored or emphasized the importance of the rectosigmoid junction in continence or constipation on and off for 200 years. Here, we revisit its significance using high-resolution colonic manometry.

METHODS

Manometry, using an 84-channel water-perfused catheter, was performed in 18 healthy volunteers.

RESULTS

The rectosigmoid junction registers as an intermittent pressure band of 26.2 ± 7.2 mmHg, or intermittent phasic transient pressure increases at a dominant frequency of 3 cpm and an amplitude of 28.6 ± 8.6 mmHg; or a combination of tone and transient pressures, at a single sensor, 10-17 cm above the anal verge. Features are its relaxation or contraction in concert with relaxation or contraction of the anal sphincters when a motor pattern such as a high-amplitude propagating pressure wave or a simultaneous pressure wave comes down, indicating that such pressure increases or decreases at the rectosigmoid junction are part of neurally driven programs. We show that the junction is a site where motor patterns end, or where they start; e.g. retrogradely propagating cyclic motor patterns emerge from the junction.

CONCLUSIONS

The rectosigmoid junction is a functional sphincter that should be referred to as the sphincter of O'Beirne; it is part of the "braking mechanism," contributing to continence by keeping content away from the rectum. In an accompanying case report, we show that its excessive presence in a patient with severe constipation can be a primary pathophysiology.

Evaluation of Operative Notes for Splenic Flexure Mobilization: Are the Key Aspects Being Reported?

Background: Given the importance of operative documentation, we reviewed operative notes for surgeries that required splenic flexure mobilization (SFM) to determine their accuracy. Materials and Methods: We performed a retrospective review of 51 operative notes for complete SFMs performed at a single institution from January 2015 to June 2020. Results: None of the operative notes reported a rationale for performing SFM, use of preoperative imaging to guide technical approach, reasoning for the operative method and mobilization approach used, or specific steps taken to ensure that SFM was done safely. Most reports did not include technical details, with one-third of the notes merely reporting that "the splenic flexure was mobilized." Conclusions: Increased awareness about the lack of operative documentation of the critical aspects of the SFM could stimulate initiatives to standardize the SFM method and improve the quality of operative notes for SFM.

Carl Toldt Centennial, Surgeon and Anatomist

Carl Florian Toldt was an Austrian anatomist who made meaningful contributions worldwide and defined what is one of the most important surgical landmarks in abdominal surgery. Through his research studies, the embryologic dissection plane known as the "White Line of Toldt" represents an important anatomical landmark that helps to mobilize either the ascending or descending colon. His career spanned over 45 years, beginning in Verona and continuing to Prague and Vienna. He was an author of several innovative books and scientific articles regarding micro- and macroscopic anatomy. In addition, he received numerous recognitions and prizes for his work, making him an essential figure in the medical scientific community. Even a street in Vienna, Karl-Toldt-Weg, is named in his honor. The purpose of this historical article is to celebrate and honor Toldt 100 years following his death, remembering his scientific contributions to the medical and surgical fields and giving thanks for his numerous accomplishments. This article brings light to the man behind the eponym.

Exploration of colonic looping patterns in undisturbed cadaveric specimens

INTRODUCTION

This study examines sex differences in the disposition of the sigmoid and transverse segments of the colon in undisturbed cadaveric abdomens and relates these findings to the anecdotal observation that colonoscopy is more challenging in females through the formation of tortuous bowel loops.

MATERIALS AND METHODS

One hundred and twenty two undisturbed cadaveric abdomens were inspected. Three distinct configuration grades were separately assigned to the sigmoid and transverse segments of the colon on the basis of the pattern of the bowel loops observed in situ. Pearson's chi-squared test was used to analyze sex differences in bowel loop configuration and Spearman's rank correlation coefficient was calculated to identify co-occurrence of configuration grades in the subjects.

RESULTS

For the transverse segment, females had higher configuration grades corresponding to longer bowel loops with greater redundancy, compared to males (p = .000047). There was no sex difference in the sigmoid segment grade (p = .21636). Sigmoid and transverse segment grades were highly correlated in the subjects (coefficient = 0.9994).

CONCLUSION

Sex differences in the configuration grades of the sigmoid or transverse colonic segments may be a significant contributing factor to increased difficulty of colonoscopy in females.

Mesentery - a 'New' organ

The mesentery is the organ in which all abdominal digestive organs develop, and which maintains these in systemic continuity in adulthood. Interest in the mesentery was rekindled by advancements of Heald and Hohenberger in colorectal surgery. Conventional descriptions hold there are multiple mesenteries centrally connected to the posterior midline. Recent advances first demonstrated that, distal to the duodenojejunal flexure, the mesentery is a continuous collection of tissues. This observation explained how the small and large intestines are centrally connected, and the anatomy of the associated peritoneal landscape. In turn it prompted recategorisation of the mesentery as an organ. Subsequent work demonstrated the mesentery remains continuous throughout development, and that abdominal digestive organs (i.e. liver, spleen, intestine and pancreas) develop either on, or in it. This relationship is retained into adulthood when abdominal digestive organs are directly connected to the mesentery (i.e. they are 'mesenteric' in embryological origin and anatomical position). Recognition of mesenteric continuity identified the mesenteric model of abdominal anatomy according to which all abdominal abdomino-pelvic organs are organised into either a mesenteric or a non-mesenteric domain. This model explains the positional anatomy of all abdominal digestive organs, and associated vasculature. Moreover, it explains the peritoneal landscape and enables differentiation of peritoneum from the mesentery. Increased scientific focus on the mesentery has identified multiple vital or specialised functions. These vary across time and in anatomical location. The following review demonstrates how recent advances related to the mesentery are re-orientating the study of human biology in general and, by extension, clinical practice.

Comparison of the sigmoid take-off with other definitions of the rectosigmoid junction: A retrospective comparative cohort analysis

BACKGROUND

The diversity in definitions for the rectosigmoid junction is becoming a major obstacle in standardizing optimal treatment of rectal cancers. The study aimed to determine the average distance of the sigmoid take-off from the anal verge and its association with individual factors.

MATERIALS AND METHODS

Patients diagnosed with rectal and sigmoid colon cancer in our centre from January 2010 to December 2018 were retrospectively enrolled in the cancer group. The results of 200 controls without colorectal disease were also reviewed (normal group). The distance of different landmarks and margins of cancer from the anal verge were retrieved from computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy findings.

RESULTS

The cancer group comprised 635 patients (381 men, median age: 64 years). The average distances of the sigmoid take-off from the anal verge measured in CT and MRI were comparable (P = 0.483). On MRI, the average distance of the sigmoid take-off from the anal verge in the cancer group was comparable with that of the normal group (P = 0.070). Multivariate regression revealed that the distance of the sigmoid take-off from the anal verge was associated with the distances of the sacral promontory (P < 0.001) and peritoneal reflection (P < 0.001) from the anal verge.

CONCLUSION

The cancer distributions of patients varied widely with the application of different definitions. The point of sigmoid take-off is an intuitive landmark influenced by individual factors. The measurement of the sigmoid take-off by different researchers in both CT and MRI revealed good consistency. Further studies regarding the clinical significance of this definition are still needed.

A video guide of five access methods to the splenic flexure: the concept of the splenic flexure box

AIM

The aim of this study was to describe all the possible approaches for laparoscopic splenic flexure mobilization (SFM), each suitable for specific situations, and create an illustrated system to show SFM approaches in an easy and practical way to make it easy to learn and teach.

METHODS

Two different phases. First part: Cadaver-based study of the colonic splenic flexure anatomy. In order to demonstrate the different approaches, a balloon was placed through the colonic hepatic flexure in the lesser sac without sectioning any of the fixing ligaments of the splenic flexure. Second part: A real case series of laparoscopic SFM.

RESULTS

First part: 11 cadavers were dissected. Five potential approaches to SFM were found: anterior, trans-omentum, lateral, medial infra-mesocolic, and medial trans-mesocolic. The illustrative system developed was named: Splenic Flexure "Box"(SFBox). Second part: One of the types of SFM described in first part was used in five patients with colorectal cancer. Each laparoscopic approach to the splenic flexure was illustrated in a video accompanied by illustration aids delineating the access.

CONCLUSION

With the cadaver dissection and subsequent demonstration in real-life laparoscopic surgery, we have shown five types of laparoscopic splenic flexure mobilization. The Splenic Flexure "Box" is a useful way to learn and teach this surgical maneuver.

Surgical treatment of a colon neoplasm of the splenic flexure: a multicentric study of short-term outcomes

AIM

The optimal surgical treatment of splenic flexure neoplasm is still not well defined. Extended right hemicolectomy (ERH) and left colic resection (LCR) have been proposed but conclusive evidence concerning postoperative morbidity and oncological results is lacking. The aim of this study was to analyse the short-term outcomes after surgery for splenic flexure cancer with regard to surgical procedure and surgeon's specialty.

METHODS

This was a multicentre study on patients who underwent surgery for primary colon cancer of the splenic flexure.

RESULTS

From 2004 to 2015, 324 patients fulfilled the criteria for inclusion into the study; 270 (83.4%) had elective surgery while 54 (16.6%) had emergency resection: 158 (48.8%) underwent ERH and 166 (51.2%) LCR; 176 (54.3%) procedures were performed by colorectal surgeons, 148 (46.7%) by general surgeons. In the ERH group a significantly higher rate of emergency operations was carried out (P = 0.005). After elective surgery, no significant differences between ERH and LCR concerning 30-day mortality (3.3% vs 2.0%) and the need for reoperation (10.6% vs 7.4%) were found. Nodal harvesting was significantly higher in the ERH and colorectal surgeon groups in any clinical scenario. At multivariate analysis, age and smoking habit were predictive of the need for reoperation and major morbidity while the general surgeon group showed a higher risk of anastomotic failure (OR = 1.92; P = 0.168).

CONCLUSION

We analysed the largest series in literature of curative resections for splenic flexure tumours. The optimal procedure still remains debatable as ERH and LCR appear to achieve comparable short-term outcomes. Surgeon's specialty seems to positively affect patient's outcomes.

Ex vivo specimen MRI and pathology confirm a rectosigmoid mesenteric waist at the junction of the mesorectum and mesocolon

AIM

Continuity of the mesentery has recently been established and may provide an anatomical basis for optimal colorectal resectional surgery. Preliminary data from operative specimen measurements suggest there is a tapering in the mesentery of the distal sigmoid. A mesenteric waist in this area may be a risk factor for local recurrence of colorectal cancer. This study aimed to investigate the anatomical characteristics of the mesentery at the colorectal junction.

METHOD

In this cross-sectional study, 20 patients were recruited. After planned colorectal resection, the surgical specimens were scanned in a MRI system and subsequently dissected and photographed as per national pathology guidelines. Mesenteric surface area and linear measurements were compared between MRI and pathology to establish the presence and location of a mesenteric waist.

RESULTS

Specimen analysis confirmed that a narrowing in the mesenteric surface area was consistently apparent at the rectosigmoid junction. Above the anterior peritoneal reflection, the surface area and posterior distance of the mesentery of the upper rectum initially decreased before increasing as the mesentery of the sigmoid colon. These anatomical properties created the appearance of a mesenteric 'waist' at the rectosigmoid junction. Using the anterior reflection as a reference landmark, the rectosigmoid waist occurred at a mean height of 23.6 and 21.7 mm on MRI and pathology, respectively.

CONCLUSION

A rectosigmoid waist occurs at the junction of the mesorectum and mesocolon, and is a mesenteric landmark for the rectum that is present on both radiology and pathology.

Whole transcriptional analysis identifies markers of B, T and plasma cell signaling pathways in the mesenteric adipose tissue associated with Crohn's disease

Background

Crohn’s disease (CD) is a multifactorial disease characterized by chronic intestinal inflammation. The increased visceral adiposity near the affected intestinal area, of which mesenteric adipose tissue (MAT) is the main component, is a feature of CD. Both protective and pathological roles have been attributed to this disease-associated tissue in CD. To understand the contribution of MAT to CD pathophysiology, a molecular and cellular signature of disease-associated MAT in CD patients was provided.

Methods

We performed an observational study with whole transcriptional analysis by RNA sequencing (RNA-seq) of MAT and ileal mucosa from CD patients with active disease and controls. qPCR and immunohistology were performed for validation analysis.

Results

RNA-seq identified 17 significantly regulated genes (|FC| > 1.5; FDR < 0.05) in CD-MAT compared to non-IBD controls, with a marked upregulation of plasma cell genes (i.e., IGLL5, MZB1, CD79A, POU2AF1, FCRL5, JCHAIN, DERL3, SDC1, PIM2). A less strict statistical cutoff value (|FC| > 1.5, nominal p ≤ 0.05) yielded a larger list of 651 genes in CD-MAT compared to controls. CD ileum showed the significant regulation compared to control ileum of 849 genes (|FC| > 1.5; FDR < 0.05) or 2654 genes (|FC| > 1.5, nominal p ≤ 0.05). Ingenuity Pathway Analysis revealed the significant regulation of pathways related to T- and B cell functionality in the MAT of CD patients. Despite the differences between the MAT and ileal signatures of CD patients, we identified a subset of 204 genes significantly modulated in both tissues compared to controls. This common signature included genes related to the plasma cell signature. Genes such as S100A8, S100A9 (calprotectin) and IL1B, which are associated with acute inflammatory response, were exclusively regulated in the ileal mucosa of CD disease. In contrast, some genes encoding for lymphocyte receptors such as MS4A1, CD3D and CD79A were exclusively regulated in CD-MAT, exhibiting a different pattern of immune cell activation compared to the ileal mucosa in CD patients. qPCR and immunohistology confirmed the presence of large infiltrates of CD3⁺ CD20⁺ lymphocytes and CD138⁺ plasma cells in CD-MAT.

Conclusion

Our data strongly supports the role of CD-associated MAT as a site for T-, B- and plasma cell activation, and suggests that it could also act as a reservoir of memory immune responses.

Wuda granule, a traditional Chinese herbal medicine, ameliorates postoperative ileus by anti-inflammatory action

BACKGROUND

Postoperative ileus (POI) is a temporary disturbance in gastrointestinal motility following surgery, and intestinal inflammatory response plays a critical role in the pathogenesis of POI. Wuda granule (WDG), a gastrointestinal prokinetic Chinese herbal medicine, is prescribed to promote recovery of gastrointestinal function after abdominal surgery. However, it has remained unclear whether WDG shows anti-inflammatory effects in POI. In the present study, we investigated the effects of WDG in a rat POI model and attempted to clarify the detailed mechanisms of action.

METHOD

Experimental POI was induced in adult male SD rats by intestinal manipulation (IM). WDG were orally administered after surgery at the same points (6 h, 12 h, 18 h, 24 h). Histological changes of mesenterium, levels of cytokines, and CD68 and iNOS expression were determined in rats treated or not with WDG. We also investigated the transcriptome profile of rats treated with WDG in a POI model.

RESULTS

Experimental POI in rats was characterized by a marked intestinal and systemic inflammatory response. WDG significantly inhibited the infiltration of neutrophils and macrophages, reduced the levels of IL-6, and CRP, and inhibited protein expressions of CD68 and iNOS in mesentery. Comparison analysis showed that there are 1432 differentially expressed genes (DEGs) between the POI and CON sample, whereas 331 DEGs between the WDG -treated sample and the POI group. And 16 DEGs were shared by the POI vs CON and WDG vs POI groups, among which 6 hub genes associated with immune system processes were identified and verified.

CONCLUSIONS

WDG treatment ameliorates the impaired gastrointestinal motility in the rat model of POI through inhibiting the inflammatory response of mesentery.

Development of a Novel Technique to Dissect the Mesentery That Preserves Mesenteric Continuity and Enables Characterization of the ex vivo Mesentery

Introduction: The conventional model of abdominal anatomy described multiple mesenteries. Dissection techniques were based on this. Recent studies demonstrate the mesentery is continuous from duodenojejunal flexure to anorectal junction. Given this, it is important to update dissection techniques related to the mesentery in the cadaveric setting. Materials and Methods: A technique of mesenteric dissection was developed and tested in a cohort of 20 adult human cadavers (12 male and 8 female). As the technique enabled excision of the mesentery as a single unit, it was possible to characterize the anatomy of the ex vivo mesentery. Results: The technique developed enabled dissection of an intact and continuous mesentery in all cadavers examined. Examination of the ex vivo mesentery demonstrated that a mesoduodenum was present in all cases. The mesentery was continuous from the mesoduodenum to the mesorectum and ended at the level of the anorectal junction. Conclusions: A technique was developed that reproducibly enabled dissection of an intact and continuous mesentery from the duodenum to the anorectal junction. A mesoduodenum was consistently observed and noted to be in continuity with the remainder of the mesentery.

5-year outcome after complete mesocolic excision for right-sided colon cancer: a population-based cohort study

BACKGROUND

The benefits of extensive lymph node dissection as performed in complete mesocolic excision are still debated, although recent studies have shown an association with improved long-term outcomes. However, none of these studies had an intention-to-treat design or aimed to show a causal effect; therefore in this study, we aimed to estimate the causal oncological treatment effects of complete mesocolic excision on right-sided colon cancer.

METHODS

We did a population-based cohort study involving prospective data collected from four hospitals in Denmark. We compared the oncological outcome data of patients at one centre performing central lymph node dissection and vascular division after almost complete exposure of the proximal part of the superior mesenteric vein (ie, the complete mesocolic excision group) with three other centres performing conventional resections with unstandardised and limited lymph node dissection (ie, non-complete mesocolic excision; control group). We included data for all patients in the Capital Region of Denmark undergoing elective curative-intent right-sided colon resections for stages I-III colon cancer, as categorised by the Union for International Cancer Control (UICC; 5th edition), from June 1, 2008, to Dec 31, 2013. Patients were followed-up for 5·2 years after surgery. The primary outcome was the cumulative incidence of recurrence after 5·2 years of surgery. Inverse probability of treatment weighting and competing risk analyses were used to estimate the possible causal effects of complete mesocolic excision. This study is registered with ClinicalTrials.gov, number NCT03754075.

FINDINGS

1069 patients (813 in the control group and 256 in the complete mesocolic excision group) underwent curative-intent elective surgery for right-sided colon cancer during the study period. None of the patients were lost to follow-up regarding survival or recurrence status, and consequently no patient was censored in the analyses. The 5·2-year cumulative incidence of recurrence was 9·7% (95% CI 6·3-13·1) in the complete mesocolic excision group compared with 17·9% (15·3-20·5) in the control group, and the absolute risk reduction of complete mesocolic excision after 5·2 years was 8·2% (95% CI 4·0-12·4; p=0·00015). In the control group, 145 (18%) of 813 patients were diagnosed with a recurrence and 281 (35%) died during follow-up, whereas in the complete mesocolic excision group 25 (10%) of 256 patients were diagnosed with a recurrence and 75 (29%) died during follow-up.

INTERPRETATION

This study shows a causal treatment effect of central mesocolic lymph node excision on risk of recurrence after resection for right-sided colon adenocarcinoma. Complete mesocolic excision has the potential to reduce the risk of recurrence and improve long-term outcome after resection for all UICC stages I-III of right-sided colon adenocarcinomas.

FUNDING

The Tvergaard Fund, Helen Rude Fund, Krista and Viggo Petersen Fund, Olga Bryde Nielsen Fund, and Else and Mogens Wedell-Wedellsborg Fund.

A brief review of recent discoveries in human anatomy

In the last few years, a cluster of anatomical discoveries has been reported which overturned the long existing dogmas about the structure and function of human body. First to come was the discovery that established the existence of a lymphatic system pertaining to the central nervous system (CNS). CNS was believed to be anatomically immune privileged owing to the absence of any lymphatics and presence of the blood-brain barrier around it, but latest research has established beyond any reasonable doubt that true lymphatic channels carry immune cells in meninges thus challenging the existing theory. Studies also supported the presence of a 'Glymphatic system' (created by the perivascular spaces lined with the leptomeninges and a sheath of glial cells) in the CNS draining interstitial metabolic waste from CNS. The second discovery unraveled the previously unknown parts of the human mesentery in adult and established that it is a continuous entity all along the intra-abdominal gut tube against the previous notion that it is fragmented in the adult humans. A very recently reported third discovery demonstrated a previously unknown tissue component-'interstitium'-a networked collagen bound fluid-filled space existent in a number of human organs. All these structures bear considerable applied importance towards the pathogenesis, prognostic and diagnostic investigations and management of human diseases. This article attempts to present a brief review of all three remarkable discoveries and emphasizes their applied importance within the realm of medical sciences.

Volvulus of the ascending colon due to failure of zygosis: A case report and review of the literature

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The ascending colon has been described as a retroperitoneal organ however it may occasionally have a long mesentery.

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The process of peritoneal zygosis is incompletely understood and is subject to perturbation leading to many abnormalities.

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The excessive mobility may predispose to volvulus of this intestinal segment.

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There is often a long symptomatic prodrome before volvulus occurs during which the observant surgeon may intervene.

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The mesentery has gained new relevance with respect to its role in the contemporary management of surgical diseases.

Introduction

Volvulus of the mobile ascending colon is a serious complication of a subtle embryological abnormality that frequently goes unrecognised. There has been renewed interest in the development of the mesentery because of its relevance to the contemporary management of surgical diseases. This case is presented to illustrate the dire consequences of missing this diagnosis and to review the fascinating embryology of the condition as well as its clinical implications.

Presentation of case

We report on a 23-year-old male who presented with signs and symptoms of distal small bowel obstruction after a long prior history of intermittent right lower quadrant pain. At laparotomy, a 360-degree counter-clockwise volvulus of the entire right colon was noted as the result of an excessively long ascending mesocolon and unattached hepatic flexure. All gangrenous bowel was resected with primary ileocolic anastomosis performed thereafter. The patient did well post-operatively and was subsequently discharged.

Discussion

Interruption of the in-utero events of fixation known as peritoneal zygosis lead to a persistence of the mesocolon in parts of the bowel that ordinarily are retroperitoneal. The events that lead to this anomaly are poorly understood and have been subject to controversy for centuries. New insights have challenged surgical dogma and informed new surgical techniques. Its true incidence is probably underestimated because of its indolent clinical prodrome, and it requires a high index of suspicion.

Conclusion

Failure of peritoneal zygosis is implicated in a myriad of clinical conditions. Expeditious recognition and intervention in the prodromal period can avert potentially disastrous complications.

A plea for an extension of the anatomical nomenclature: Organ systems

This article is the third part of a series aimed at correcting and extending the anatomical nomenclature. Communication in clinical medicine as well as in medical education is extensively composed of anatomical, histological, and embryological terms. Thus, to avoid any confusion, it is essential to have a concise, exact, perfect and correct anatomical nomenclature. The Terminologia Anatomica (TA) was published 20 years ago and during this period several revisions have been made. Nevertheless, some important anatomical structures are still not included in the nomenclature. Here we list a collection of 156 defined and explained technical terms related to the anatomical structures of the human body focusing on the digestive, respiratory, urinary and genital systems. These terms are set for discussion to be added into the new version of the TA.

The Toldt fascia: A historic review and surgical implications in complete mesocolic excision for colon cancer

To clarify the anatomic concept of Toldt fascia, based on the literature review and the surgical anatomic dissection using laparoscopic or robotic approach. We undertook review of the historic literature and surgical videos from 250 patients with colorectal cancer operated on laparoscopically or robotically to discuss the surgical implications of Toldt fascia in complete mesocolic excision for colon cancer. Toldt fascia, sandwiched by the overlying mesothelial layer of the mesocolon and underlying mesothelial layer of the retroperitoneum, comprised loose fibrous tissues with minute vessels inside, and was contiguous from the ileocecal mesentery radix to the upper rectum. Surgical dissection plane is readily developed within the Toldt fascia; however, any attempt to dissect along the interface between Toldt fascia and the overlying mesocolon or underlying retroperitoneum failed. Within the anatomic territory of kidney, Toldt fascia fused with Gerota fascia, and then extended in all directions: upward to the dosal surface of the duodenum, liver and pancreas; medially to fuse with the adventitia layer of the abdominal aorta; laterally, it tapered at the area below the reflection of visceral and parietal peritoneum; and downward, it became a thin membranous structure covering the gonadal vessels, ureters and retroperitoneal structures and ended at the upper rectum, where it met the junction of endopelvic fascia and proper fascia of the rectum. The present study demonstrated that Toldt fascia is a natural embryonic dissection plane for the precise conduction of complete mesocolic excision for colon cancer.

Inclusion of the Mesentery in Ileocolic Resection for Crohn's Disease is Associated With Reduced Surgical Recurrence

BACKGROUND AND AIMS

Inclusion of the mesentery during resection for colorectal cancer is associated with improved outcomes but has yet to be evaluated in Crohn's disease. This study aimed to determine the rate of surgical recurrence after inclusion of mesentery during ileocolic resection for Crohn's disease.

METHODS

Surgical recurrence rates were compared between two cohorts. Cohort A [n = 30] underwent conventional ileocolic resection where the mesentery was divided flush with the intestine. Cohort B [n = 34] underwent resection which included excision of the mesentery. The relationship between mesenteric disease severity and surgical recurrence was determined in a separate cohort [n = 94]. A mesenteric disease activity index was developed to quantify disease severity. This was correlated with the Crohn's disease activity index and the fibrocyte percentage in circulating white cells.

RESULTS

Cumulative reoperation rates were 40% and 2.9% in cohorts A and B [P = 0.003], respectively. Surgical technique was an independent determinant of outcome [P = 0.007]. Length of resected intestine was shorter in cohort B, whilst lymph node yield was higher [12.25 ± 13 versus 2.4 ± 2.9, P = 0.002]. Advanced mesenteric disease predicted increased surgical recurrence [Hazard Ratio 4.7, 95% Confidence Interval: 1.71-13.01, P = 0.003]. The mesenteric disease activity index correlated with the mucosal disease activity index [r = 0.76, p < 0.0001] and the Crohn's disease activity index [r = 0.70, p < 0.0001]. The mesenteric disease activity index was significantly worse in smokers and correlated with increases in circulating fibrocytes.

CONCLUSIONS

Inclusion of mesentery in ileocolic resection for Crohn's disease is associated with reduced recurrence requiring reoperation.

Vascular anatomy of the transverse mesocolon and bidirectional laparoscopic D3 lymph node dissection for patients with advanced transverse colon cancer

Laparoscopic D3 lymph node dissection for transverse colon cancer is technically demanding because of complicated anatomy. Here, we reviewed the vascular structure of the transverse mesocolon, explored the extent of the base of the transverse mesocolon, and evaluated the feasibility and oncological safety of D3 lymph node dissection. We retrospectively reviewed the clinical records of 42 patients with advanced transverse colon cancer who underwent curative surgery and D3 dissection at Kyushu University Hospital between January 2008 and December 2015. We examined the venous and arterial anatomy of the transverse mesocolon of each resection and compared surgical outcomes between patients who underwent laparoscopic D3 (Lap D3) and open D3 (Open D3) dissection. Patients included two with Stage I, 18 with Stage II, 20 with Stage III, and two with Stage IVA. Thirty-six (85.7%) and six (14.3%) patients underwent Lap D3 or Open D3, respectively. The tumor sizes of the Open D3 and Lap D3 groups were 7.8 and 3.7 cm, respectively (P < 0.001). The Lap D3 group had significantly less blood loss (26 mL vs 272 mL, P = 0.002). The other outcomes of the two groups were not significantly different, including 3-year overall survival (87.7% vs 83.3%, P = 0.385). We observed four patterns of the middle colic artery (MCA) arising from the superior mesenteric artery (SMA), and the frequency of occurrence of a single MCA was 64.3%. The right-middle colic vein (MCV) was present in 92.9% of resections and served as a tributary of the gastrocolic trunk, and 90.5% of the left MCVs drained into the superior mesenteric vein (SMV). The root of the transverse mesocolon was broadly attached to the head of the pancreas and to the surfaces of the SMV and SMA. Laparoscopic D3 lymph node dissection may be tolerated by patients with advanced transverse colon cancer.

Anatomy of the mesentery: Historical development and recent advances

Recent appraisals of mesenteric anatomy clarify its structure and show a continuous and helical-shaped organ. This new model signifies a departure from the conventional model which described multiple, separate "mesenteries". Renaissance anatomists depicted the mesentery as a continuous structure. Events that led to replacement of a continuous with a fragmented model span several centuries. In effect, the scientific and clinical community has come full circle and back to the Renaissance model. Here we review the historical development of our understanding of the mesentery. We discuss how the fragmented model replaced the continuous model. Additionally, we examine factors that contributed to recent advances in mesenteric anatomy as these present new opportunities for systematic investigation.

The Peritoneum: Beyond the Tissue - A Review

Background: Despite its complexity, the peritoneum is usually underestimated in classical medical texts simply as the surrounding tissue (serous membrane) of the gut. Novel findings on physiology and morphology of the peritoneum and mesothelial cell exist but they are usually focused or limited to Continuous Ambulatory Peritoneal Dialysis research and practice. This review aims to expose, describe and analyze the most recent evidence on the peritoneum’s morphology, embryology and physiology.

Materials and Methods: A literature review was performed on Pubmed and MEDLINE. With no limit of publication date, original papers and literature reviews about the peritoneum, the peritoneal cavity, peritoneal fluid, and mesothelial cells were included (n = 72).

Results: Peritoneum develops in close relationship to the gut from an early period in embryogenesis. Analyzing together the development of the primitive gut and the surrounding mesothelium helps understanding that the peritoneal cavity, the mesenteries and other structures can be considered parts of the peritoneum. However, some authors consider that structures like the mesenteries are different to the peritoneum. The mesothelial cell has a complex ultrastructural organization with intercellular junctions and apical microvilli. This complexity is further proven by the large array of functions like selective fluid and cell transport; physiological protective barrier; immune induction, modulation, and inhibition; tissue repair and scarring; preventing adhesion and tumoral dissemination; cellular migration; and the epithelial-mesenchymal transition capacity.

Conclusion: Recent evidence on the anatomy, histology, and physiology of the peritoneum, shows that this structure is more complex than a simple serous membrane. These results call for a new conceptualization of peritoneum, and highlight the need of adequate research for identifying clinical relevance of this knowledge.

Festschrift for Patrick Ronan (PR) O'Connell (also known as ROCON): reconciling surgery and science

Ronan O Connell's clinical activities were fundamentally based on accurate data. His scientific outputs were based on similarly high quality data. Anybody who trained with him and in particular those who trained with him on more than occasion base their clinical and scientific activities on a similar approach. His many clinical, scientific and political achievements and accolades will be detailed in the articles in this Festschrift. There is an advancement that is important to me personally and that I would like to attribute to his influence. Exceptional and highly reproducible technique underpinned his surgery and explained the outcomes his patients experienced. Recent clarification of the anatomical basis of these techniques (the mesenteric basis) provides a unifying platform across which to reconcile human abdominal anatomy and surgery.

Surgical and oncological outcomes after complete mesocolic excision in right-sided colon cancer compared with conventional surgery: a retrospective, single-institution study

PURPOSE

The aim of the study was whether complete mesocolic excision (CME) with central vascular ligation (CVL) is associated with a survival benefit compared with traditional procedure in right-sided colon cancer.

METHODS

Overall, 251 consecutive patients underwent surgery for right colon cancer between 2007 and 2012. After exclusion, 95 subjects received non-CME surgery before 2010, and 97 subjects received CME surgery after January 2010, when we started to perform CME systematically. The number of lymph nodes, morbidity, and mortality was analyzed. Overall survival (OS) and disease-specific survival (DSS) were investigated.

RESULTS

The median number of examined lymph nodes was 33.28 in the CME group and 26.92 in the non-CME group, p < 0.001. Postoperative complications were 21.6% in the CME group and 17.8% in the non-CME group, without significant difference. One out of 192 patients died. Three-year OS was 88% in the CME group and 71% in the non-CME group (p = 0.003). In stage II, 3-year DSS was 97% in the CME group and 86% in the non-CME group. In stage III, the 3-year DSSs in the CME and in the non-CME groups were 86 and 67%, respectively (p < 0.001). Cox's regression showed that CME (p = 0.0012), the number of lymph nodes (p = 0.029), and TNM stage (p < 0.001) were significant independent predictors of DSS at 3 years.

CONCLUSION

Surgical standardization of CME with CVL for right-sided colon cancer is associated with better staging and prognosis, particularly in UICC stage II and III. This study shows that CME is safe and reproducible with acceptable morbidity.

Revisiting Toldt Fascia Through Robotic Top-down and Medial-to-lateral Apporach - Video Vignette

In this video (Toldt fascia.wmv), we demonstrated anatomic features of Toldt fascia, based on the meticulous dissection and high-resolution images inherent in robotic surgery. Toldt fascia is sandwiched by the overlying mesothelial layer of the mesocolon and underlying mesothelial layer of the retroperitoneum, comprised loose fibrous tissues with minute vessels inside, and is contiguous from the ileocecal mesentery radix to the upper rectum. The medial-to-lateral surgical dissection plane is readily developed within the Toldt fascia; however, any attempt to dissect along the interface between Toldt fascia and the overlying mesocolon or underlying retroperitoneum failed. This article is protected by copyright. All rights reserved.

The length and complexity of mesentery are related to the locoregional recurrence of the carcinoma in gut

Local-regional relapse is the main recurrence pattern of the carcinoma in gut, and leads to poor prognosis. With the development of the total mesorectal and complete mesocolic excision (TME/CME), the local relapse rate of colorectal cancer has significantly decreased. People attributed it to the improvement of lymphadenectomy, but lymphatic metastasis is difficult to explain the local relapse in N0 patients. Previously, we have proven the existence of "Metastasis V" in mesogastrium and mesocolorectum, and supposed that it is one of the major risk factors in local recurrence. Therefore, we think complete mesentery excision can effectively reduce "Metastasis V", prevent cancer leak and improve patients' outcome. Due to the different length and complexity of mesentery, the difficulty of mesentery excision varies. Meanwhile, there is an obvious distinction of local relapse rate in different alimentary tract, even in different segment of a same organ. Thus we assume that the length and complexity of mesentery may be a risk factor of the locoregional recurrence of the carcinoma in gut.

Laparoscopic Colorectal Surgery for Cancer: What Is the Role of Complete Mesocolic Excision and Splenic Flexure Mobilization?

Laparoscopic colorectal surgery for cancer is nowadays routinely performed worldwide. After the introduction by Heald of total mesorectal excision for rectal cancer, also a complete mesocolic excision has been advocated as an essential surgical step to improve oncologic results in patients with colon cancer. The complete removal of mesocolon with high ligation of the main mesenteric arteries and veins and the mobilization of splenic flexure are well-known but still debated in western surgical society. The authors reviewed the literature and outlined the rationale and the results of splenic flexure mobilization and complete mesocolic excision in laparoscopic surgery for colorectal cancer.

Laparoscopic Wide Mesocolic Excision and Central Vascular Ligation for Carcinoma of the Colon

Background and Aims:

The principle of complete mesocolic excision for colon cancer has been introduced to improve oncologic outcome. However, this approach is scantily discussed for laparoscopic surgery and there is a lack of randomized trials. This study examined oncologic and clinical outcome after laparoscopic wide mesocolic excision and central vascular ligation for colon cancer.

Material and Methods:

This is a review of prospectively gathered data from a single-institution colorectal cancer database. This study was conducted in the Central Hospital of Central Finland. From January 2003 to December 2011, 222 patients underwent laparoscopic colonic resections with wide mesocolic excision and central vascular ligation in the multimodal setting. The main measures of outcome were cancer recurrence and survival, with early recovery, 30d-mortality and morbidity, reoperation, readmission, and late complications as secondary outcomes.

Results:

The median follow-up was 5.5 (interquartile range (IQR) = 3.7–8.0) years. The 5-year overall survival for all 222 patients was 80.2% and disease-specific survival was 87.5%, and for those 210 R0-patients with stage I–III disease, 83.9% and 91.3%, respectively. The 5-year disease-free survival was 85.8%: stage I was 94.7%, stage II was 90.8%, and stage III was 75.6% ( p = 0.004). Increasing lymph node ratio significantly decreased the 5-year disease-free survival. Conversion rate to open surgery was 12.2%. Thirty-day mortality was 1.3% and morbidity, 19.7%. Median postoperative hospital stay was 5 (IQR = 3–7) days.

Conclusion:

Laparoscopic wide mesocolic excision and central vascular ligation for colon cancer resulted in good long-term oncologic outcome. Randomized trials are needed to show that laparoscopic complete mesocolic excision technique would become the standard of care for the carcinoma of the colon.

Laparoscopic complete mesocolic excision with central vascular ligation in 600 right total mesocolectomies: Safety, prognostic factors and oncologic outcome

BACKGROUND

To analyze our experience with laparoscopic right Mesocolectomy in right colonic cancers.

METHODS

600 consecutive patients were studied.

RESULTS

Mortality was 0.5%; morbidity was 35.5%. Mean mesocolic area was 15339 ± 1639 mm3, specimen length 24.3 ± 3.3 cm, distance from the tumor to high tie was 103 ± 6 mm and mean lymph nodes harvested was 27 ± 3; mesocolic plane was achieved in 81% of cases. Survival was 83%; stratified survival in patients with stage II, IIIA/B and in the subgroup of stage IIIC patients with negative apical nodes was 88.7%, 72.4%, 71.4% respectively; stage IIIC patients with positive apical nodes showed poor survival (27.7%). Recurrence occurred in 177 patients (29.5%) and was mainly systemic (22.7%). At the multivariate analysis, "non mesocolic" plane of resection, positive N3 apical nodes and CEA levels >5 ng/dL were found to be independent prognostic factors.

CONCLUSIONS

Laparoscopic right Mesocolectomy showed to be safe and yielded surgical specimens of high quality, with impact on survival; positive N3 apical nodes and "non mesocolic" planes were independently associated to poor outcome.

The mesentery: structure, function, and role in disease

Systematic study of the mesentery is now possible because of clarification of its structure. Although this area of science is in an early phase, important advances have already been made and opportunities uncovered. For example, distinctive anatomical and functional features have been revealed that justify designation of the mesentery as an organ. Accordingly, the mesentery should be subjected to the same investigatory focus that is applied to other organs and systems. In this Review, we summarise the findings of scientific investigations of the mesentery so far and explore its role in human disease. We aim to provide a platform from which to direct future scientific investigation of the human mesentery in health and disease.

Cancer arising from the remnant mucosa of the ileoanal anastomosis leading to pouchectomy

Ileal pouch-related adenocarcinoma remains a rarity; thus, guidelines on treatment are currently lacking. We present this case of a 54-year-old man who underwent restorative proctocolectomy with stapled ileal pouch–anal anastomosis formation for familial adenomatous polyposis during the 1980s. Despite undergoing annual surveillance endoscopy, the patient was noted to be anaemic and passing fresh blood per anus. Endoscopy and radiological investigation revealed the presence of a pouch-related adenocarcinoma. This was subsequently treated with short-course radiotherapy and pouch excision. The patient remains well until now and will follow six-monthly surveillance protocols with a transition to annual surveillance after 2 years.

The mesentery in Crohn's disease: friend or foe?

PURPOSE OF REVIEW

This article assesses the role of the mesentery in Crohn's disease.

RECENT FINDINGS

The mesentery is centrally positioned both anatomically and physiologically. Overlapping mesenteric and submucosal mesenchymal contributions are important in the pathobiology of Crohn's disease. Mesenteric contributions explain the topographic distribution of Crohn's disease in general and mucosal disease in particular. Operative strategies that are mesenteric based (i.e. mesocolic excision) may reduce rates of postoperative recurrence.

SUMMARY

The net effect of mesenteric events in Crohn's disease is pathologic. This can be targeted by operative means.

VIDEO ABSTRACT

http://links.lww.com/COG/A18.