Urogenital function following robotic and laparoscopic rectal cancer surgery: meta-analysis.

BACKGROUND: Mixed results are reported on clinical and cancer outcomes in laparoscopic rectal cancer surgery (LRCS) compared with robotic rectal cancer surgery (RRCS). However, more favourable functional outcomes are reported following RRCS. This study compared urinary and sexual function following RRCS and LRCS in male and female patients. METHODS: A systematic review and meta-analysis of urinary and sexual function after RRCS and LRCS was performed following PRISMA and MOOSE guidelines, and registered prospectively with PROSPERO (ID:CRD42020164285). The functional outcome reporting tools most commonly included: the International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) and Female Sexual Function Index (FSFI). Mean scores and changes in mean scores from baseline were analysed using RevMan version 5.3. RESULTS: Ten studies were included reporting on 1286 patients. Some 672 patients underwent LRCS, of whom 380 (56.5 per cent) were men and 116 (17.3 per cent) were women (gender not specified in 176 patients, 26.2 per cent). A total of 614 patients underwent RRCS, of whom 356 (58.0 per cent) were men and 83 (13.5 per cent) were women (gender not specified in 175 patients, 28.5 per cent). Regarding urinary function in men at 6 months after surgery, IPSS scores were significantly better in the RRCS group than in the LRCS group (mean difference (MD) -1.36, 95 per cent c.i. -2.31 to -0.40; P = 0.005), a trend that persisted at 12 months (MD -1.08, -1.85 to -0.30; P = 0.007). ΔIIEF scores significantly favoured RRCS at 6 months [MD -3.11 (95%CI -5.77, -0.44) P <0.021] and 12 months [MD -2.76 (95%CI -3.63, -1.88) P <0.001] post-operatively. Mixed urinary and sexual function outcomes were reported for women. CONCLUSION: This meta-analysis identified more favourable urinary and erectile function in men who undergo robotic compared with conventional laparoscopic surgery for rectal cancer. Outcomes in women did not identify a consistently more favourable outcome in either group. As robotic rectal cancer surgery may offer more favourable functional outcomes it should be considered and discussed with patients.

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.

Resectional surgery for malignant disease of abdominal digestive organs is not surgery of the organ itself, but also that of the mesenteric organ.

Despite large strides in molecular oncology, surgery remains the bedrock in the management of visceral cancer. The primacy of surgery cannot be understated and a mesenteric (i.e. ontogenetic) approach is particularly beneficial to patients. Heald greatly advanced the management of rectal cancer with his description of the anatomical foundation of total mesorectal excision (TME), dramatically improving outcomes worldwide with this mesenteric-based approach. Moreover, complete mesocolic excision (CME) based on similar principles is becoming popular. Introduced by Hohenberger, CME resembles TME insofar as it emphasises strictly anatomical dissection along embryological planes to detach an intact (i.e. "complete") mesentery with peritoneal envelope. CME also incorporates "central" vascular ligation (CVL) which broadly correlates with the "D3 lymphadenectomy" of Eastern literature. As many surgeons already practise anatomical and mesenteric-based surgery, it is unclear how the putative benefits of CME (including CVL) arise. Herein, we argue that these may relate to a more extensive resection of the mesentery, and thus mesenteric tumour deposits within the connective tissue lattice of the mesentery, and not necessarily the lymphadenectomy alone. We believe the connective tissue interface between the bowel wall and mesentery provides an alternative mode of spread of pathogenic elements. Whilst this remains a suggestion only, it would explain the histological independence of tumour deposits and why a greater mesenterectomy could be associated with benefits in survival. If this argument holds, it follows that resectional surgery for digestive organ malignancy is not surgery of the organ itself (or lymphatics only), but also that of the contiguous mesentery.

Using fluorescence lymphangiography to define the ileocolic mesentery: proof of concept for the watershed area using real-time imaging.

Recent advances in mesenteric science have demonstrated that the mesentery is a continuous structure with a 'watershed' area at the mesenteric apex between the right colon and terminal ileum, where lymphatic flow can proceed either proximally or distally. With this new understanding of the anatomy, functional features are emerging, which can have an impact on surgical management. Fluorescence lymphangiography or lymphoscintigraphy with indocyanine green allows real-time visualization of lymphatic channels, which highlights sentinel lymph nodes and may facilitate identification of the ideal margins for mesenteric lymphadenectomy during bowel resection for colon cancer. By using this novel technology, it is possible to demonstrate a watershed area in the ileocolic region and may facilitate more precise mesenteric dissection. In the present study, we provide proof of concept for the ileocolic watershed area using fluorescence lymphangiography.

The effect of purse-string approximation versus linear approximation of ileostomy reversal wounds on morbidity rates and patient satisfaction: the 'STOMA' trial.

BACKGROUND: Ileostomy reversal is associated with surgical site infection (SSI) rates as high as 37%. Recent literature suggests that employing a purse-string approximation (PSA) of the reversal wound reduces this rate of SSI. Thus we wished to perform a randomised controlled trial to compare SSI rates in purse-string versus linear closure (PLC) wounds following ileostomy reversal. METHODS: A randomised, controlled trial was conducted at University Hospital Limerick. Sixty-one patients undergoing ileostomy reversal were included. Thirty-four patients were randomised to PSA and 27 patients to linear closure. The primary endpoint was incidence of SSI and secondary endpoints measured were quality of life and satisfaction with cosmesis. Statistical analysis was performed on a per protocol basis using SPSS version 22.0. RESULTS: Three patients in the PSA group developed an SSI compared to 8 in the PLC group at 30 days (8 vs 30%, p = 0.03). The mean time to SSI diagnosis was faster in the PSA group (3 vs 12.3 days, p = 0.08). Patients who developed SSI experienced a longer mean length of stay (6.8 vs 11.4 days, p = 0.012). On multivariate analysis, PLC was the only predictive factor of SSI formation (p < 0.001). There was no difference in patient satisfaction between the two study groups (p = 0.14). CONCLUSIONS: PSA of wounds following ileostomy reversal significantly reduces SSI formation compared to linear approximation without any effect on patient satisfaction.

Initial experience with a dual-console robotic-assisted platform for training in colorectal surgery.

BACKGROUND: Minimally invasive surgery is associated with several patient-related benefits, including reduced length of hospital stay and reduced blood loss. Robotic-assisted surgery offers many advantages when compared with standard laparoscopic procedures, including a stable three-dimensional binocular camera platform, motion smoothing and motion scaling, improved dexterity and ergonomics. There are limited data on the effectiveness of the dual-console DaVinci Xi platform for teaching resident surgeons. The goal of this study was to examine preliminary outcomes following the introduction of a dual-console robotic platform in our institution. METHODS: A retrospective review of our prospectively maintained patient database was performed. The first ten dual-console resident-performed procedures in colorectal surgery were compared with matched cases performed on a single console by the trainer. Patient demographics, operative times and patient outcomes were compared. RESULTS: Twenty patients were included in this study. There was no significant difference in console time (p = 0.46) or total operative time (p = 0.52) when residents and trainers were compared. Patient outcomes were equivalent, with no difference in length of stay, morbidity or mortality. CONCLUSIONS: The DaVinci Xi dual-console platform is a safe and effective platform for training junior surgeons. The dual-console system has the potential to alter surgical training pathways.

Neoadjuvant therapy does not affect lymph node ratio in rectal cancer.

AIMS: Recently, lymph-node ratio (LNR) has emerged as a prognostic tool in staging rectal cancer. Studies to date have demonstrated threshold values above and below which survival is differentially altered. Neoadjuvant therapy significantly reduces the number of lymph node retrieved. The aim of the present study was to determine the effect of neoadjuvant therapy on LNR and its prognostic properties. METHODS: Consecutive patients who underwent curative rectal cancer resections in a single institution from 2007 to 2010 were reviewed. LNR was stratified into five subgroups of 0, 0.01-0.17, 0.18-0.41, 0.42-0.69 and 0.7-1.0 based on a previous study. The effect of neoadjuvant therapy on lymph node retrieval, LNR, locoregional (LR) and systemic recurrence (SR), disease-free (DFS) and overall survival (OS) was compared between patients who did (Neoadjuvant) and did not (Surgery Alone) receive neoadjuvant therapy. RESULTS: Neoadjuvant and Surgery Alone groups were comparable in gender, age and tumour stage. The number of lymph nodes retrieved were significantly lower in the Neoadjuvant group (p < 0.01). However, LNR remained similar in both groups (p = 0.36). There was no statistical difference in the DFS and OS between the Neoadjuvant and Surgery Alone groups at the various LNR cut off values in patients with AJCC Stage 3 tumours. CONCLUSIONS: LNR ratio remains unaltered despite reduced lymph node retrieval after neoadjuvant therapy in rectal cancer. LNR may therefore be a more reliable prognostic indicator in this subgroup of patients.

Identification of the optimal visual recording system in open abdominal surgery - a prospective observational study.

INTRODUCTION: Current methodologies used to record and render the surgeon's point of view in open operative surgery remain limited. Chief among these limitations is a failure to demonstrate, in high definition and magnification, the planar roadmap that surgeons utilise in colorectal surgery. The high magnification and high resolution views provided during laparoscopic surgery simultaneously capture the planar road map and surgeon's point of view. We developed an arm-mounted external laparoscope (exoscope) system and compared its performance against multiple standard recording modalities. METHODS: Following ethical approval and informed consent, open colorectal procedures were recorded using five separate methodologies. Each methodology was assessed and compared. RESULTS: Most of the methodologies utilised scored poorly at one if not more levels. The arm-mounted external laparoscope (exoscope) scored highest in rendering the surgeon's point of view while simultaneously achieving high resolution and high magnification rendition of operative field (p < .001). This methodology was tested in a number of operative contexts within which it reproducibly and consistently scored highly. CONCLUSIONS: The arm-mounted exoscope is the optimal means of rendering the surgeon's point of view of anatomic planes during open colorectal surgery.

Spatial variation of the colonic microbiota in patients with ulcerative colitis and control volunteers.

OBJECTIVES: The relevance of spatial composition in the microbial changes associated with UC is unclear. We coupled luminal brush samples, mucosal biopsies and laser capture microdissection with deep sequencing of the gut microbiota to develop an integrated spatial assessment of the microbial community in controls and UC. DESIGN: A total of 98 samples were sequenced to a mean depth of 31,642 reads from nine individuals, four control volunteers undergoing routine colonoscopy and five patients undergoing surgical colectomy for medically-refractory UC. Samples were retrieved at four colorectal locations, incorporating the luminal microbiota, mucus gel layer and whole mucosal biopsies. RESULTS: Interpersonal variability accounted for approximately half of the total variance. Surprisingly, within individuals, asymmetric Eigenvector map analysis demonstrated differentiation between the luminal and mucus gel microbiota, in both controls and UC, with no differentiation between colorectal regions. At a taxonomic level, differentiation was evident between both cohorts, as well as between the luminal and mucosal compartments, with a small group of taxa uniquely discriminating the luminal and mucosal microbiota in colitis. There was no correlation between regional inflammation and a breakdown in this spatial differentiation or bacterial diversity. CONCLUSIONS: Our study demonstrates a conserved spatial structure to the colonic microbiota, differentiating the luminal and mucosal communities, within the context of marked interpersonal variability. While elements of this structure overlap between UC and control volunteers, there are differences between the two groups, both in terms of the overall taxonomic composition and how spatial structure is ascribable to distinct taxa.

A meta-analysis to determine the oncological implications of conversion in laparoscopic colorectal cancer surgery.

AIM: Laparoscopic colon and rectal cancer surgery is oncologically equivalent to open resection, but the impact of conversion is undetermined. The aim of this study was to assess the oncological outcome and predictive factors associated with conversion. METHOD: A comprehensive search for published studies examining the associated factors and outcome of conversion from laparoscopic to open colorectal cancer resection was performed adhering to PRISMA (Preferred Reporting Items in Systematic Reviews and Meta-analyses) guidelines. Only randomized control trials and prospective studies were included. Each study was reviewed and the data extracted. Random effects methods were used to combine data. RESULTS: Fifteen studies, including 5293 patients, met the inclusion criteria. Of these 4391 patients had a completed laparoscopic resection and 902 were converted to an open resection. The average conversion rate of the studies was 17.9 ± 10.1%. Meta-analysis showed completed laparoscopic surgery favoured lower 30-day mortality (OR 0.134, 95% CI 0.047-0.385, P < 0.0001), lower long-term disease recurrence (OR 0.634, 95% CI 0.421-0.701, P < 0.023) and lower overall mortality (OR 0.512, 95% CI 0.417-0.629, P < 0.0001). Factors negatively associated with completion of laparoscopic surgery were male gender (P = 0.011), rectal tumour (P = 0.017), T3/T4 tumour (P = 0.009) and node-positive disease (P = 0.009). Completed laparoscopic surgery was also associated with a lower body mass index (BMI; mean difference -0.93 kg/m(2) , P = 0.004). CONCLUSION: The results suggest that conversion from laparoscopic to open colorectal cancer resection is influenced by patient and tumour characteristics and is associated with an adverse perioperative outcome. Although confounding factors such as advanced tumour stage and elevated BMI are present, unsuccessful laparoscopic surgery appears to be associated with an adverse long-term oncological outcome.

Ratios derived from an array of standard haematological indices predict the oncological outcome in colon cancer.

AIM: The interaction between inflammation and cancer is well established. Surrogate markers of systemic inflammation, such as the neutrophil/lymphocyte ratio (NLR), may be associated with the long-term oncological outcome. The present study aimed to characterize the relationship between several ratios derived from haematological indices using a classification and regression tree analysis. METHOD: Haematological white-cell ratios were established for all patients undergoing colonic cancer resection with curative intent (n = 436) in a regional cancer centre. The optimal ratios associated with overall survival (OS) were established in a training set (n = 386) using a classification and regression tree (CRT) technique. The association between ratios and OS was assessed in a separate test set (n = 50). Within the test set, two groups were generated based on each ratio (one group above and one group below the cut-off value identified in the training set). The association between ratios and OS was assessed using a stepwise Cox proportional-hazards regression model. RESULTS: The following ratios, identified by the CRT, were associated with adverse OS in the test set: an NLR of ≥ 3.4 [hazard ratio (HR) = 3.4, P < 0.001]; and a white-cell-count/lymphocyte ratio (WLR) of ≥ 5.28 (HR = 4.1, P = 0.03). CONCLUSION: This is the first study to apply recursive partitioning in determining the relationship between haematological ratios and OS in colon cancer. Haematological ratios were predictive of oncological outcome. What does this paper add to the literature? This study suggests an association between systemic inflammation and oncological outcome.

Correlations between colonic crypt mucin chemotype, inflammatory grade and Desulfovibrio species in ulcerative colitis.

AIM: The colonic mucus gel layer is composed of mucins that may be sulphated or sialyated. Sulphated mucins predominate in health while in ulcerative colitis (UC) sulphation is reduced. These differences result directly from inflammatory events. It may also be hypothesized that they arise in part from alterations in the colonic microbiota, particularly changes in the burden of sulphated mucin-metabolizing species, such as Desulfovibrio (DSV) bacteria. The aim of this study was to correlate colonic mucin chemotypes and inflammatory scores in health and UC and relate these changes to changes in the colonization of colonic crypts by DSV. METHOD: Paired colonic biopsies from 34 healthy controls (HC) and 19 patients with active UC were collected for the purpose of parallel histological and microbiological assessment. High-iron diamine and Alcian blue staining and haematoxylin and eosin of mucosal biopsy specimens were used to assess histological changes within the clinical spectrum of UC. Quantitative real-time polymerase chain reaction analysis was employed to determine the total and DSV copy number within the colonic crypts. RESULTS: Compared with HC, the mucin chemotype in UC was less sulphated and inversely correlated with the degree of mucosal inflammation. A weak but significant negative correlation was found between the abundance of sulphated mucins and DSV burden. CONCLUSION: Mucin composition strongly correlates with the degree of mucosal inflammation, and to a lesser extent with DSV burden. These data suggest that mucin chemotype and DSV burden are linked phenomena and highlight the need to consider changes in mucin chemotype in the setting of microbial dysbiosis occurring within the colitic colon. What does this paper add to the literature? Decreased sulphation of mucins has been associated with inflammation in ulcerative colitis. Currently there are few data describing the relationship between microbial species and changes in mucin chemotype. This study validates previous findings and presents evidence of changes in mucin chemotype occurring in tandem with coherent changes in the microbiota within crypt niches.

Terminology and nomenclature in colonic surgery: universal application of a rule-based approach derived from updates on mesenteric anatomy.

Recent developments in colonic surgery generate exciting opportunities for surgeons and trainees. In the first instance, the anatomy of the entire mesenteric organ has been clarified and greatly simplified. No longer is it regarded as fragmented and complex. Rather it is continuous from duodenojejunal flexure to mesorectum, spanning the gastrointestinal tract between. Recent histologic findings have demonstrated that although apposed to the retroperitoneum, the mesenteric organ is separated from this via Toldt's fascia. These fundamentally important observations underpin the principles of complete mesocolic excision, where the mesocolic package is maintained intact, following extensive mesenterectomy. More importantly, they provide the first opportunity to apply a canonical approach to the development of nomenclature in resectional colonic surgery. In this review, we demonstrate how the resultant nomenclature is entirely anatomic based, and for illustrative purposes, we apply it to the procedure conventionally referred to as right hemicolectomy, or ileocolic resection.

Digital sculpting in surgery: a novel approach to depicting mesosigmoid mobilization.

BACKGROUND: The aim of the present study was to develop a unique anatomic replica of the mesocolon using digital graphical software in order to provide an educational template for mesosigmoidectomy. METHODS: The colon and mesocolon were fully mobilized from ileocecal to mesorectal levels in a cadaver. Both colon and mesocolon provided a template from which to generate a three dimensional replica in ZBrush. The model was deformed in ZBrush, to compare and contrast current and classic interpretations of mesosigmoidal topography. An animation was developed in which the replica was deformed to mimic operative mobilization. Contiguous shape changes were captured in two-and-a-half-dimensional (2.5D) screen snapshots. This was repeated for medial to lateral and lateral to medial mobilization of the mesosigmoid. RESULTS: Topographic differences between classic and current appraisals of mesocolic anatomy were evident in 2.5D format. Using the model generated, contiguous shape changes during mesosigmoidal mobilization (i.e., between the left mesocolon, mobile/apposed mesosigmoid, and mesorectum) were replicated in animation format. By extracting and compiling 2.5D screen grabs a pictorial chronology of mobilization was developed. CONCLUSIONS: Recent advances in mesocolic topography can be captured and rendered using advanced digital sculpting software with high-end graphics capabilities. This approach permits a depiction of contiguous changes in mesosigmoidal topography during mesosigmoidal mobilization. A compilation of images in either animation or screen grab format obviates the interpolation of shape changes required using standard educational approaches.

Vertical rectus abdominis myocutaneous flap and quality of life following abdominoperineal excision for rectal cancer: a multi-institutional study.

BACKGROUND: To obtain a clear surgical margin, abdominoperineal excision (APE) for rectal cancer frequently leaves a large perineal defect surrounded by irradiated tissue. A vertical rectus abdominis myocutaneous (VRAM) flap may facilitate healing of this wound. The current study aims to determine the effect of VRAM flap perineal reconstruction following APE on patient quality of life (QOL). METHODS: This is a retrospective cohort study from a prospectively collected database. Data on QOL were assessed via telephone questionnaire using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-C30, EORTC QLQ-C29 and the Cleveland Clinic QOL questionnaires. RESULTS: Twenty-seven patients underwent primary perineal closure, and 12 patients underwent a VRAM flap perineal reconstruction. The mean duration of follow-up was 16.8 months. Overall, there was no significant difference in the Cleveland Clinic QOL score between groups (VRAM vs. no VRAM: 0.7 ± 0.2 vs. 0.7 ± 0.2, p 0.735). Patients in the VRAM group had lower levels of fatigue (5.5 ± 9.9 vs. 23.6 ± 19.2, p 0.004). Patients in the VRAM group had reduced sore skin scores around the stoma site (11.0 ± 16.2 vs. 31.8 ± 31.1, p 0.036). VRAM flap was associated with an increased incidence of abdominal wall hernia (VRAM vs. no VRAM: 25 % vs. 0 %, p 0.024). CONCLUSIONS: This study is limited by its non-randomized retrospective design and relatively small sample size. A significant difference in patient QOL was not demonstrated between VRAM flap and primary perineal closure after APE for rectal cancer. Further studies in this area are warranted.

Laparoscopic versus open appendicectomy performed by adult general surgeons in pre-teenage years children: a single-centre experience.

INTRODUCTION: The utilisation of laparoscopic appendicectomy (LA) in children remains contentious despite the well-recognised advantages of laparoscopic surgery. The purpose of this study was to compare intraoperative and postoperative outcomes in LA and open appendicectomy (OA) when performed by adult general surgeons outside specialist paediatric practice in younger children. METHODS: A retrospective review of all patients under the age of 13 who underwent LA for suspected appendicitis over a two-year period was conducted. These were case-matched with an equivalent number of patients who underwent OA during the same period. Intraoperative and postoperative outcomes were compared. RESULTS: Fifty-one patients underwent LA during the study period. Patient demographics were statistically equivalent with the OA cohort. A statistically significant longer median operating time (58 vs 49min) was noted in the LA group, but intraoperative outcomes were otherwise comparable. LA, when compared with OA, was associated with a significant improvement in postoperative length of stay (2 vs 3 days, p < 0.001), postoperative complication rate (0% vs 6%, p = 0.01), negative appendicectomy rate (3.9% vs 17.6%, p < 0.001) and 30-day readmission rate (0% vs 5.9%, p = 0.03). No patients in the LA group required conversion to open surgery. CONCLUSION: LA can be safely delivered by adult general surgeons to younger paediatric populations outside the setting of paediatric specialist practice, with statistically significant improvements in postoperative outcomes noted when compared with OA. These findings are of importance in the current healthcare context where adult general surgeons continue to perform the majority of paediatric appendicectomies.

Circulating fibrocytes and Crohn's disease.

BACKGROUND: Despite advances in medical therapy, there remains no effective preventive or non-surgical therapeutic option for fibrostenotic Crohn's disease (CD). Symptomatic recurrences are common, necessitating reintervention. Intestinal fibroblasts mediate stricture formation, but their exact source is unclear. Recent evidence indicates that circulating fibrocytes drive fibrosis through differentiation into fibroblasts and the production of extracellular matrix proteins. The aim of this review is to describe current understanding of the pathophysiology underlying fibrosis in CD, the cellular and molecular biology of fibrocytes and their role in CD. METHODS: The electronic literature (January 1972 to December 2012) on 'circulating fibrocytes' and 'Crohn's fibrosis' was reviewed. RESULTS: Circulating fibrocytes appear universally involved in organ fibrosis. A complex array of cytokines, chemokines and growth factors regulate fibrocyte biology, and these are associated with fibrogenesis in CD. The cytokines transforming growth factor ß1, connective tissue growth factor and interleukin 13, overexpressed in the strictured Crohn's intestine, promote fibrocyte generation and/or differentiation. CONCLUSION: Levels of circulating fibrocytes are raised in conditions marked by exaggerated fibrosis. These and other observations prompt a characterization of fibrocyte activity in CD with a view to investigating a pathogenic role.

BRAF mutation is associated with distinct clinicopathological characteristics in colorectal cancer: a systematic review and meta-analysis.

AIM: Colorectal cancer is a heterogeneous disease with multiple underlying genetic mutations resulting in different phenotypes. Mutation in the v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) proto-oncogene is an important event in the methylator pathway. There is no consensus, however, on the clinicopathological characteristics associated with BRAF mutation. METHOD: A comprehensive search for published studies examining the effect of BRAF mutation on colorectal cancer was performed. Random effects methods were used to combine data. RESULTS: Data were retrieved from 21 studies describing 9885 patients. BRAF associated colorectal cancer is associated with proximal tumour location (OR 5.222, 95% CI 3.801-7.174, P < 0.001), T4 tumours (OR 1.761, 95% CI 1.164-2.663, P = 0.007) and poor differentiation (OR 3.816, 95% CI 2.714-5.365, P < 0.001) and is negatively associated with male sex (OR 0.623, 95% CI 0.505-0.769, P < 0.001), age of diagnosis under 60 years (OR 0.453, 95% CI 0.280-0.733, P = 0.001) and rectal cancer (OR 0.266, 95% CI 0.122-0.422, P < 0.001). CONCLUSION: BRAF mutation appears to be associated with distinct, unfavourable clinicopathological characteristics in colorectal cancer.

Review of nomenclature in colonic surgery--proposal of a standardised nomenclature based on mesocolic anatomy.

The standardisation of the surgical management of rectal cancer has been facilitated by adoption of an anatomic surgical nomenclature. Thus, "total mesorectal excision" substituted "anterior resection" or "proctosigmoidectomy" and implies resection of both rectum and mesorectum. Similar trends towards standardisation of colonic surgery are ongoing, yet there remains a heterogeneity of terminology utilised (eg, "right hemicolectomy", "ileocolic resection", and "total mesocolic excision"). Recent descriptions of mesocolic anatomy provide an opportunity to standardise colonic resection according to a more precise and informative anatomic nomenclature. This article aims to firstly emphasise the central importance of the mesocolon and from this propose a related nomenclature for resectional colonic surgery. Introduction of a standardised nomenclature for colonic resection is a necessary step towards standardisation of colonic surgery in general.