The Development of the Mesenteric Model of Abdominal Anatomy.

Recent advances in mesenteric anatomy have clarified the shape of the mesentery in adulthood. A key finding is the recognition of mesenteric continuity, which extends from the oesophagogastric junction to the mesorectal level. All abdominal digestive organs develop within, or on, the mesentery and in adulthood remain directly connected to the mesentery. Identification of mesenteric continuity has enabled division of the abdomen into two separate compartments. These are the mesenteric domain (upon which the abdominal digestive system is centered) and the non-mesenteric domain, which comprises the urogenital system, musculoskeletal frame, and great vessels. Given this anatomical endpoint differs significantly from conventional descriptions, a reappraisal of mesenteric developmental anatomy was recently performed. The following narrative review summarizes recent advances in abdominal embryology and mesenteric morphogenesis. It also examines the developmental basis for compartmentalizing the abdomen into two separate domains along mesenteric lines.

Optimal management of functional anorectal pain: a systematic review and network meta-analysis.

Functional anorectal is idiopathic and characterised by severe and potentially intractable anorectal pain. The current review aims to appraise available evidence for the management of functional anorectal pain and synthesise reported outcomes using network meta-analysis. PubMed, CENTRAL and Web of Science databases were searched for studies investigating treatments for functional anorectal pain. The primary outcome was clinical improvement of symptoms and the secondary outcome was pain scores reported during follow-up. A Bayesian network meta-analysis of interventions was performed. A total of 1538 patients were included from 27 studies. Intramuscular injection of triamcinolone, sacral neuromodulation (SNM) and biofeedback were most likely to be associated with improvement in symptoms [SUCRA (triamcinolone) = 0.79; SUCRA (SNM) = 0.74; SUCRA (Biofeedback) = 0.61]. Electrogalvanic stimulation (EGS), injection of botulinum toxin A and topical glyceryl trinitrate (GTN) were less likely to produce clinical improvement [SUCRA (EGS) = 0.53; SUCRA (Botox) = 0.30; SUCRA (GTN) = 0.27]. SNM and biofeedback were associated with the largest reductions in pain scores [mean difference, range (SNM) = 4.6-8.2; (Biofeedback) = 4.6-6]. As biofeedback is noninvasive and may address underlying pathophysiology, it is a reasonable first-line choice in patients with high resting pressures or defecation symptoms. In patients with normal resting pressures, SNM or EGS are additional options. Although SNM is more likely to produce a meaningful response compared to EGS, EGS is noninvasive and has less morbidity. Whilst triamcinolone injection is associated with symptomatic clinical improvement, the magnitude of pain reduction is less.

Management of colon-invading renal cell carcinoma: Operative technique and systematic review.

Invasion into adjacent organs by non-metastatic renal cell carcinoma (RCC) occurs in 1% of patients suitable for resection. Colonic invasion is rare and presents technical challenges. No prospective data exists to guide management of these patients. We present the first reported case of a colon-invading RCC managed with simultaneous open right radical nephrectomy and extended right hemicolectomy. PubMed, Scopus and EMBASE databases were searched for relevant case reports reporting management of colon-invading renal cell carcinoma. Case reports, case series and cohort studies were eligible. A chart review was performed on a patient who presented with right-sided colon-invading RCC. Four previously reported cases were identified. The current case was managed with simultaneous open radical nephrectomy and extended right hemicolectomy. The patient remains well six months postoperatively with no evidence of disease recurrence. Histopathological evaluation of the resected specimen confirmed a T4 clear cell RCC with sarcomatoid differentiation. Colon-invading RCC is rare. This is the first reported case of right-sided, colon-invading RCC treated with radical resection. The current case confirms radical resection is a feasible management strategy for similar presentations. En bloc resection of involved organs remains the only potentially curative option for locally advanced disease.

A meta-analysis of marsupialisation versus none in the treatment of simple fistula-in-ano.

INTRODUCTION: Marsupialisation of post-fistulotomy wounds results in a smaller raw surface area and may improve postoperative outcomes. However, it remains a variable practice. We performed a systematic review and meta-analysis to evaluate the effectiveness of marsupialisation in the treatment of simple fistula-in-ano. MATERIALS AND METHODS: PubMed, EMBASE and Cochrane databases were searched for relevant articles from inception until April 2020. All trials that reported on marsupialisation in anal fistula treatment were included. The primary outcome measure was time to complete healing, while secondary outcomes included recurrence, pain scores and incontinence. Random effects models were used to calculate pooled effect size estimates. A sensitivity analysis was performed. RESULTS: Six randomised controlled trials were included capturing 461 patients. The mean (SD) age of the cohort was 39.31 (± 8.71) years. There were 395 males (85.7%). All fistulae were of the cryptoglandular aetiology. On random effects analysis, marsupialisation was associated with a significantly shorter time to healing compared with no marsupialisation (SMD - 0.97 weeks, 95% CI = - 1.36 to - 0.58, p < 0.00001). However, there was no difference in recurrence (RD = - 0.00, 95% CI = - 0.02 to 0.02, p = 0.72), pain scores at 24 h (SMD - 0.03, 95% CI = - 0.56 to 0.50, p = 0.91) or incontinence (RD = - 0.01, 95% CI = - 0.05 to 0.02, p = 0.42). On sensitivity analysis, focusing exclusively on fistulotomy for simple fistula-in-ano, the results for time to healing, recurrence and incontinence remained similar. CONCLUSIONS: Marsupialisation of fistulotomy wounds for simple fistula-in-ano is associated with a significantly shorter healing time, but similar recurrence, pain scores at 24 h and incontinence rates, compared with omitting marsupialisation.

Effect of liposomal bupivacaine on opioid requirements and length of stay in colorectal enhanced recovery pathways: A systematic review and network meta-analysis.

AIM: Reducing postoperative opioid consumption is a key aim of enhanced recovery after colorectal surgery protocols. Potential solutions include anaesthetic techniques such as local infiltration of anaesthetic agents or transversus abdominis plane (TAP) blocks. This study aimed to assess the efficacy of liposomal bupivacaine (LB) for colorectal resections, across a variety of anaesthetic techniques. METHODS: PubMed, Scopus and Embase databases were searched for relevant studies assessing LB, administered by any anaesthetic technique. The primary outcome was postoperative morphine consumed (milligrams) and the secondary outcome was length of stay (days). A Bayesian network meta-analysis comparing LB versus non-LB analgesia was performed alongside meta-regression for different surgical approaches. RESULTS: Twelve trials were included, with a total of 2512 patients. LB-based wound infiltration was most likely to reduce length of stay followed by TAP block with LB (sum under the cumulative ranking [SUCRA] 85.55 and 70.26, respectively). TAP block with LB was most likely to reduce morphine requirements, followed by wound infiltration with LB (SUCRA 83.94 and 75.73, respectively). Compared to standard analgesia, LB-based wound infiltration reduced morphine usage (mean difference 36.64 mg, 95% credibility interval 15.64-59.20) and length of stay (mean difference 1.79 days, 95% credibility interval 0.59-3.81). On meta-regression, the findings held for minimally invasive surgery only. CONCLUSION: Although LB-based interventions were associated with reduced postoperative morphine requirements and length of stay in this network meta-analysis, the confidence in these estimates was graded as very low. Further well-executed trials are required before LB can be recommended as a first-line agent.

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.

Anatomy of the mesentery: Current understanding and mechanisms of attachment.

An understanding of the anatomy of the mesentery is necessary to undertake any appraisal of the literature on its development. The mesentery is the collection of tissues that maintain all abdominal digestive organs in position and connection with the rest of the body. Therefore, it is also necessary to detail the exact mechanisms that maintain the mesentery in position. We explore these mechanisms, including the supportive functions of structures such as Toldt's fascia, the peritoneal reflection, and vascular connections, in this article.

Development of mesenteric tissues.

Mesothelial, neurovascular, lymphatic, adipose and mesenchymal tissues make up the mesentery. These tissues are pathobiologically important for numerous reasons. Collectively, they form a continuous, discrete and substantive organ. Additionally, they maintain abdominal digestive organs in position and in continuity with other systems. Furthermore, as they occupy a central position, they mediate transmission of signals between the abdominal digestive system and the remainder of the body. Despite this physiologic centrality, mesenteric tissue development has received little investigatory focus. However, recent advances in our understanding of anatomy demonstrate continuity between all mesenteric tissues, thereby linking previously unrelated studies. In this review, we examine the development of mesenteric tissue in normality and in the setting of congenital abnormalities.