Safety of robotic cholecystectomy as index training procedure: the UK experience.

AIMS: To evaluate the safety profile of robotic cholecystectomy performed within the United Kingdom (UK) Robotic Hepatopancreatobiliary (HPB) training programme. METHODS: A retrospective evaluation of prospectively collected data from eleven centres participating in the UK Robotic HPB training programme was conducted. All adult patients undergoing robotic cholecystectomy for symptomatic gallstone disease or gallbladder polyp were considered. Bile duct injury, conversion to open procedure, conversion to subtotal cholecystectomy, length of hospital stay, 30-day re-admission, and post-operative complications were the evaluated outcome parameters. RESULTS: A total of 600 patients were included. The median age was 53 (IQR 65-41) years and the majority (72.7%; 436/600) were female. The main indications for robotic cholecystectomy were biliary colic (55.5%, 333/600), cholecystitis (18.8%, 113/600), gallbladder polyps (7.7%, 46/600), and pancreatitis (6.2%, 37/600). The median length of stay was 0 (IQR 0-1) days. Of the included patients, 88.5% (531/600) were discharged on the day of procedure with 30-day re-admission rate of 5.5% (33/600). There were no bile duct injuries and the rate of conversion to open was 0.8% (5/600) with subtotal cholecystectomy rate of 0.8% (5/600). CONCLUSION: The current study confirms that robotic cholecystectomy can be safely implemented to routine practice with a low risk of bile duct injury, low bile leak rate, low conversion to open surgery, and low need for subtotal cholecystectomy.

Neurohormonal Changes in the Gut-Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery.

Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut-brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut-brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.

Laparoscopic Cholecystectomy vs Endoscopic Retrograde Cholangiopancreatography With Sphincterotomy in Elderly Patients With Acute Gallstone Pancreatitis.

BACKGROUND: Gallstone pancreatitis (GSP) is common in elderly patients and carries worse outcomes. Laparoscopic cholecystectomy (LC) is recommended for prevention of recurrent GSP. In frail populations, an endoscopic retrograde cholangiopancreatography with sphincterotomy (ERCP-s) is an alternative. Management guidelines of GSP in the elderly are lacking. This study aimed to investigate and compare management strategies for GSP in the elderly. MATERIALS AND METHODS: A retrospective comparison of outcome of patients aged ≥65 years with first presentation of GSP treated either with (1) LC only, (2) ERCP-s, (3) ERCP-S followed by LC, or (4) no intervention. RESULTS: 216 patients were included. Median age was 76 years (interquartile range 70-83). Most (80%, n = 172) had mild pancreatitis, whilst 12% (n = 26) had severe disease. 24% (n = 55) were treated with ERCP-s; 40% (n = 87) underwent LC alone; 11% (n = 23) had ERCP-s followed by LC; and 25% (n = 55) received no intervention. Patients without intervention were older (P < .001) and frailer (P < .001). The LC-only group had lower post-procedure re-admission rates of 6% (n = 5) compared to 27% (n = 14) for ERCP-s, 33% (n = 7) for ERCP-S + LC, and 31% (n = 17) for the no intervention group (P = .0001). Biliary cause mortality was highest in the no intervention group (n = 11, 20%). CONCLUSION: Laparoscopic cholecystectomy represents the gold standard for elderly patients with GSP.

What are the true benefits of robotic pancreaticoduodenectomy for patients with pancreatic cancer?

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease, and multimodal treatment including high-quality surgery can improve survival outcomes. Pancreaticoduodenectomy (PD) has evolved with minimally invasive approaches including the implementation of robotic PD (RPD). In this special report, we review the literature whilst evaluating the 'true benefits' of RPD compared to open approach for the treatment of PDAC. AREAS COVERED: We have performed a mini-review of studies assessing PD approaches and compared intraoperative characteristics, perioperative outcomes, post-operative complications and oncological outcomes. EXPERT OPINION: RPD was associated with similar or longer operative times, and reduced intra-operative blood loss. Perioperative pain scores were significantly lower with shorter lengths of stay with the robotic approach. With regards to post-operative complications, post-operative pancreatic fistula rates were similar, with lower rates of clinically relevant fistulas after RPD. Oncological outcomes were comparable or superior in terms of margin status, lymph node harvest, time to chemotherapy and survival between RPD and OPD. In conclusion, RPD allows safe implementation of minimally invasive PD. The current literature shows that RPD is either equivalent, or superior in certain aspects to OPD. Once more centers gain sufficient experience, RPD is likely to demonstrate clear superiority over alternative approaches.

Diagnostic Modalities of Non-Alcoholic Fatty Liver Disease: From Biochemical Biomarkers to Multi-Omics Non-Invasive Approaches.

Non-Alcoholic Fatty Liver Disease (NAFLD) is currently the most common cause of chronic liver disease worldwide, and its prevalence is increasing globally. NAFLD is a multifaceted disorder, and its spectrum includes steatosis to steatohepatitis, which may evolve to advanced fibrosis and cirrhosis. In addition, the presence of NAFLD is independently associated with a higher cardiometabolic risk and increased mortality rates. Considering that the vast majority of individuals with NAFLD are mainly asymptomatic, early diagnosis of non-alcoholic steatohepatitis (NASH) and accurate staging of fibrosis risk is crucial for better stratification, monitoring and targeted management of patients at risk. To date, liver biopsy remains the gold standard procedure for the diagnosis of NASH and staging of NAFLD. However, due to its invasive nature, research on non-invasive tests is rapidly increasing with significant advances having been achieved during the last decades in the diagnostic field. New promising non-invasive biomarkers and techniques have been developed, evaluated and assessed, including biochemical markers, imaging modalities and the most recent multi-omics approaches. Our article provides a comprehensive review of the currently available and emerging non-invasive diagnostic tools used in assessing NAFLD, also highlighting the importance of accurate and validated diagnostic tools.

Systematic Review and Meta-Analysis of the Impact of Bariatric Surgery on Lower Urinary Tract Symptoms in Males.

BACKGROUND: Obesity is a chronic disease with multisystem morbidity. There are multiple studies reporting the effect of bariatric surgery on cardiovascular and metabolic disease, but few examine its impact on lower urinary tract symptoms. This article aims to perform a systematic review with meta-analysis, to determine the effects of bariatric surgery on lower urinary tract symptoms in male patients. METHODS: Medline, Embase, conference proceedings, and reference lists were searched for studies reporting the quantitative measurement of lower urinary tract symptoms score pre- and postweight loss surgery. The primary outcome was International Prostate Symptom Score (IPSS) before and after bariatric surgery. Secondary outcomes were changed in body mass index (BMI) and total body weight (TBW). Weighted mean differences (MD) were calculated for continuous outcomes. RESULTS: Seven studies were included in the analysis of 334 patients undergoing bariatric surgery. Mean study follow-up was between 3 and 36 months. IPSS score ranged from 3-12.7 preoperatively and 1.9-6.9 postoperatively. There was a statistically significant improvement in the IPSS score following bariatric surgery (MD 2.82, 95% CI 0.96 to 4.69, p=0.003). Bariatric surgery also resulted in statistically significant reduction of BMI and TBW. CONCLUSION: Bariatric surgery produces a significant improvement on lower urinary tract symptoms in men with obesity. This may be due to improvement of insulin sensitivity, testosterone levels or lipid profile associated with weight loss.

A rare case of acute congestive ischaemic colitis related to combined superior and inferior mesenteric arteriovenous malformations.

Visceral arteriovenous malformations (AVMs) are extremely rare with only a few cases described within the literature. To date, no cases of ischaemic colitis related to arteriovenous malformations affecting both superior and inferior mesenteric arteries have been reported. We report the first case of acute ischaemic colitis caused by venous congestion and reduced arterial flow due to combined AVMs in the territory of superior and inferior mesenteric arteries in a 51-year-old patient. After a multidisciplinary meeting, interventional radiology embolization was considered to be of unlikely benefit due to extensive varicosities; therefore, surgical treatment in the form of open subtotal colectomy and end ileostomy was performed. This case report demonstrates the severity and the complexity in the management of AVM-related ischaemic colitis, together with a review of the literature.

A Meta-analysis of the Impact of Bariatric Surgery on Back Pain.

BACKGROUND: The functional aspects of obesity are increasingly recognised as a significant clinical and public health concern. Whilst there is substantial evidence for the beneficial impact of bariatric surgery on metabolic and cardiovascular disease, there is less understanding of the quantitative effect of bariatric surgery on back pain. The aim of this meta-analysis was to assess the impact of bariatric surgery on back pain in reported studies. METHODS: Medline, Embase, conference proceedings and reference lists were searched for studies assessing quantitative back pain scores both before and after bariatric surgery. The primary outcome was visual analogue score for back pain pre- and post-bariatric surgery. Secondary outcomes were change in BMI, SF-36 quality of life scores and Oswestry Disability Index (ODI) scores. Weighted mean differences (MD) were calculated for continuous outcomes. RESULTS: Seven studies were included in the analysis of 246 patients undergoing bariatric surgery. Mean study follow-up was between 3 and 24 months. There was a statistically significant reduction in visual analogue score for back pain following bariatric surgery (MD - 3.01; 95% CI - 4.19 to - 1.89; p < 0.001). Bariatric surgery also resulted in statistically significant improvements in BMI, SF-36 score and ODI score. CONCLUSIONS: Bariatric surgery produces significant and quantifiable reductions in back pain. This may be commuted through reductions in axial load or improved quality of life, but further studies will improve understanding and aid preoperative counselling.

Self-recognition and the regulation of CD4+ T cell survival.

CD4+ T cells differentiate in the thymus from committed precursors to mature naive cells ready for peripheral circulation. Successful maturation depends on adequate but not excessive signaling upon T cell receptor (TCR) engagement of self-peptide/MHC class II molecule ligands present in the thymic environment. Persistent TCR signaling throughout development from the CD4+CD8+ to the CD4+ state is required for completion of the developmental process. Recent work has suggested that a continuation of this signaling is essential for sustained survival of CD4+ T cells once they leave the thymus but our studies suggest otherwise. Although we found clear evidence for active TCR signaling involving recognition of self-ligands in peripheral lymphoid tissues, we did not see a substantial effect of loss of such signaling on the life-time of naive CD4+ T cells. Based on a careful review of the literature, we conclude that essentially all previous claims that MHC class II recognition plays a significant role in the survival of CD4+ T cells can be reinterpreted as an effect of self-recognition on proliferation in lymphopenic environments, maintaining population numbers without a marked effect on individual cell viability. We propose a possible explanation for why, in contrast, the viability of naive CD8+ T cells appears to show such self-MHC dependence and suggest that a primary function of self-recognition by T cells may be to enhance responses to foreign antigen.

CD4+CD25+ regulatory T cells are activated in vivo by recognition of self.

Naturally occurring CD4(+)CD25(+) regulatory T cells (nT(R)) comprise a separate lineage of T cells that are essential for maintaining immunological tolerance to self. Here we demonstrate that the level of phosphorylation of the TCR zeta-chain is approximately 1.5- to 4-fold higher in nT(R) as compared with CD4(+)CD25(-) T cells. The increased level of TCR zeta-chain phosphorylation is presumably secondary to their higher affinity for self, resulting in a stronger TCR signal as it was completely blocked by treatment with anti-MHC class II. The enhanced level of TCR zeta-chain phosphorylation was correlated with the capacity of nT(R) to develop non-specific suppressor effector function following culture with IL-2 or IL-4 in the absence of TCR stimulus. Thus, a sub-population of nT(R) is activated by recognition of self-peptide-MHC class II ligands in vivo, resulting in their capacity to be induced to mediate suppressor function in vitro in the absence of TCR stimulation.

Redundancy in antigen-presenting function of the HLA-DR and -DQ molecules in the multiple sclerosis-associated HLA-DR2 haplotype.

The three HLA class II alleles of the DR2 haplotype, DRB1*1501, DRB5*0101, and DQB1*0602, are in strong linkage disequilibrium and confer most of the genetic risk to multiple sclerosis. Functional redundancy in Ag presentation by these class II molecules would allow recognition by a single TCR of identical peptides with the different restriction elements, facilitating T cell activation and providing one explanation how a disease-associated HLA haplotype could be linked to a CD4+ T cell-mediated autoimmune disease. Using combinatorial peptide libraries and B cell lines expressing single HLA-DR/DQ molecules, we show that two of five in vivo-expanded and likely disease-relevant, cross-reactive cerebrospinal fluid-infiltrating T cell clones use multiple disease-associated HLA class II molecules as restriction elements. One of these T cell clones recognizes >30 identical foreign and human peptides using all DR and DQ molecules of the multiple sclerosis-associated DR2 haplotype. A T cell signaling machinery tuned for efficient responses to weak ligands together with structural features of the TCR-HLA/peptide complex result in this promiscuous HLA class II restriction.

Self-recognition promotes the foreign antigen sensitivity of naive T lymphocytes.

Major histocompatibility complex (MHC) class I and II molecules are highly polymorphic proteins that bind and present foreign peptides to the clonally distributed alphabeta receptors (TCR) of T lymphocytes. As a population, the immature T lymphocytes generated in the thymus express a very diverse set of TCR specificities. A process of positive selection filters this broad repertoire to optimize peripheral T cells for antigen recognition in the context of available MHC products. Only those precursor T cells whose TCRs generate an adequate but not excessive signalling response to self-peptides bound to the expressed MHC proteins undergo successful maturation. Here we show that post-thymic self-recognition facilitates the antigen reactivity of mature T cells. Both experimental and physiological interruption of T-cell contact with self-peptide MHC ligands leads to a rapid decline in signalling and response sensitivity to foreign stimuli. Because the adaptive immune system must be recruited early in an infectious process when antigen is limiting, these findings suggest that positive selection ensures predictable T-cell recognition of available self-ligands, which in turn promotes efficient responses to pathogens.

TCR ligand discrimination is enforced by competing ERK positive and SHP-1 negative feedback pathways.

Functional discrimination between structurally similar self and foreign antigens is a main attribute of adaptive immunity. Here we describe two feedback mechanisms in T lymphocytes that together sharpen and amplify initial signaling differences related to the quality of T cell receptor (TCR) engagement. Weakly binding ligands predominantly trigger a negative feedback loop leading to rapid recruitment of the tyrosine phosphatase SHP-1, followed by receptor desensitization through inactivation of Lck kinase. In contrast, strongly binding ligands efficiently activate a positive feedback circuit involving Lck modification by ERK, preventing SHP-1 recruitment and allowing the long-lasting signaling necessary for gene activation. The characteristics of these pathways suggest that they constitute an important part of the mechanism allowing T cells to discriminate between self and foreign ligands.

On the role of self-recognition in T cell responses to foreign antigen.

The key role of the thymus in shaping the peripheral T cell receptor (TCR) repertoire has been appreciated for nearly a quarter of a century. For most of that time, a single model has dominated thinking about the physiological role of the positive selection process mediated by TCR recognition of self-peptides and major histocompatibility complex (MHC) molecules. This developmental filter was believed to populate secondary lymphoid tissues with T cells bearing receptors best able to recognize unknown foreign peptides associated with the particular allelic forms of the MHC molecules present in an individual. More recently, self-recognition has been suggested to regulate the viability of naïve T cells. Here we focus on new results indicating that a critical contribution of positive selection to host defense is insuring that each peripheral T cell can use self-recognition to (i) enhance TCR signaling sensitivity upon foreign antigen recognition and (ii) augment the clonal expansion that accompanies limiting foreign antigen display at early points in an infectious process. We also detail new insights into the intracellular signaling circuitry that underlies the effective discrimination between low- and high-quality ligands of the TCR and speculate on how this design might facilitate an additional contribution of self-recognition to T cell activation in the presence of foreign stimuli.