An appraisal of the computed axial tomographic appearance of the human mesentery based on mesenteric contiguity from the duodenojejunal flexure to the mesorectal level.

OBJECTIVE: The human mesentery is now regarded as contiguous from the duodenojejunal (DJ) to anorectal level. This interpretation prompts re-appraisal of computed tomography (CT) images of the mesentery. METHODS: A digital model and reference atlas of the mesentery were generated using the full-colour data set of the Visible Human Project (VHP). Seventy one normal abdominal CT images were examined to identify mesenteric regions. CT appearances were correlated with cadaveric and histological appearances at corresponding levels. RESULTS: Ascending, descending and sigmoid mesocolons were identifiable in 75%, 86% and 88% of the CTs, respectively. Flexural contiguity was evident in 66%, 68%, 71% and 80% for the ileocaecal, hepatic, splenic and rectosigmoid flexures, respectively. A posterior mesocolic boundary corresponding to the anterior renal fascia was evident in 40% and 54% of cases on the right and left, respectively. The anterior pararenal space (in front of the boundary) corresponded to the mesocolon. CONCLUSIONS: Using the VHP, a mesenteric digital model and reference atlas were developed. This enabled re-appraisal of CT images of the mesentery, in which contiguous flexural and non-flexural mesenteric regions were repeatedly identifiable. The anterior pararenal space corresponded to the mesocolon. KEY POINTS: The Visible Human Project (VHP) allows direct identification of mesenteric structures. Correlating CT and VHP allows identification of flexural and non-flexural mesenteric components. Radiologic appearance of intraperitoneal structures is assessed, starting from a mesenteric platform.

The development and structure of the mesentery.

The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of abdominal anatomy, there are multiple mesenteries. Recent findings point to an alternative model in which digestive organs are connected to a single mesentery. Given that direct evidence of this is currently lacking, we investigated the development and shape of the entire mesentery. Here we confirm that, within the abdomen, there is one mesentery in which all abdominal digestive organs develop and remain connected to. We show that all abdominopelvic organs are organised into two, discrete anatomical domains, the mesenteric and non-mesenteric domain. A similar organisation occurs across a range of animal species. The findings clarify the anatomical foundation of the abdomen; at the foundation level, the abdomen comprises a visceral (i.e. mesenteric) and somatic (i.e. musculoskeletal) frame. The organisation at that level is a fundamental order that explains the positional anatomy of all abdominopelvic organs, vasculature and peritoneum. Collectively, the findings provide a novel start point from which to systemically characterise the abdomen and its contents.

Insight into the perioperative management of direct oral anticoagulants: concerns and considerations.

INTRODUCTION: Direct oral anticoagulants (DOACs) have gained momentum in recent years in patients requiring anticoagulation for the prevention and management of venous thromboembolism and thromboembolic events caused by atrial fibrillation. The use of these agents involves potential bleeding complications, particularly during invasive procedures. With increasing use of DOACs, adequate knowledge regarding the perioperative management of patients on DOACs has become indispensable. AREAS COVERED: This review covers the indications, mechanism of action, and pharmacokinetics of DOACs and their management in different perioperative settings based on various current guidelines and practices. The role of bridging therapy with heparin and the recently developed reversal agents are also discussed. EXPERT OPINION: The perioperative management of DOACs is influenced by drug pharmacokinetics, potential comorbidities of the patient and perioperative thrombotic and bleeding risk. In low bleeding risk and minor procedures, continuing DOACs seems to be safe. Interrupting DOACs in high-risk procedures might be necessary and should be based on the elimination half-life of the drug and renal function of the patient. Further research is needed to better clarify the role of recently developed reversal agents in the perioperative setting and to identify specific laboratory tests to guide the perioperative management of DOACs.

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.

On-table urethral catheterisation during laparoscopic appendicectomy: Is it necessary?

INTRODUCTION: Laparoscopic appendicectomy (LA) is the most commonly performed surgical emergency procedure. The aim of this study was to highlight a series of iatrogenic bladder injuries during LA and suggest a simple method of prevention. METHODS: A retrospective review was carried out of all LA performed in a university teaching hospital over a two year period 2012-2013. Iatrogenic visceral injuries were identified and operative notes examined. RESULTS: During the study period 1124 appendicectomies were performed. Four iatrogenic bladder injuries occurred related to secondary trocar insertion. No patient was catheterised preoperatively. One of the injuries was identified intra-operatively, another in the early postoperative period where as two re-presented acutely unwell post-discharge from hospital. Three were repaired by laparotomy and one laparoscopically. CONCLUSION: Iatrogenic secondary trocar induced bladder injuries are a rare but preventable and potentially serious complication of LA. Urethral catheterisation during LA is a safe and simple method which can prevent this complication.

Comparative effectiveness of adrenal sparing radical nephrectomy and non-adrenal sparing radical nephrectomy in clear cell renal cell carcinoma: Observational study of survival outcomes.

INTRODUCTION: We compare the survival outcomes of patients with clear cell renal cell carcinoma (RCC) treated with adrenal sparing radical nephrectomy (ASRN) and non-adrenal sparing radical nephrectomy (NASRN). METHODS: We conducted an observational study based on a composite patient population from two university teaching hospitals who underwent RN for RCC between January 2000 and December 2012. Only patients with pathologically confirmed RCC were included. We excluded patients undergoing cytoreductive nephrectomy, with loco-regional lymph node involvement. In total, 579 patients (ASRN = 380 and NASRN = 199) met our study criteria. Patients were categorized by risk groups (all stage, early stage and locally advanced RCC). Overall survival (OS) and cancer-specific survival (CSS) were analyzed for risk groups. Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazards regression. RESULTS: The median follow-up was 41 months (range: 12-157). There were significant benefits in OS (ASRN 79.5% vs. NASRN 63.3%; p = 0.001) and CSS (84.3% vs. 74.9%; p = 0.001), with any differences favouring ASRN in all stage. On multivariate analysis, there was a trend towards worse OS (hazard ratio [HR] 1.759, 95% confidence interval [CI] 0.943-2.309, p = 0.089) and CSS (HR 1.797, 95% CI 0.967-3.337, p = 0.064) in patients with NASRN (although not statistically significant). Of these patients, only 11 (1.9%) had adrenal involvement. CONCLUSIONS: The inherent limitations in our study include the impracticality of conducting a prospective randomized trial in this scenario. Our observational study with a 13-year follow-up suggests ASRN leads to better survival than NASRN. ASRN should be considered the gold standard in treating patients with RCC, unless it is contraindicated.