Specialist-led urgent cholecystectomy for acute gallstone disease.

BACKGROUND: Despite overwhelming evidence of the clinical and financial benefit of urgent cholecystectomy, there is variable enthusiasm and uptake across the UK. In 2014, following the First National Emergency Laparotomy Audit Organisational Report, we implemented a specialist-led urgent surgery service, whereby all patients with gallstone-related pathologies were admitted under the direct care of specialist upper gastrointestinal surgeons. We have analysed 5 years of data to investigate the results of this service model. METHODS: Computerised operating theatre records were interrogated to identify all patients within a 5-year period undergoing cholecystectomy. Patient demographics, admission details, length of stay, duration of surgery, and complications were analysed. RESULTS: Between 01/01/2016 and 31/12/2020, a total of 4870 cholecystectomies were performed; 1793 (36.8%) were urgent cases and 3077 (63.2%) were elective cases. All cases were started laparoscopically; 25 (0.5%) were converted to open surgery-14 of 1793 (0.78%) urgent cases and 11 of 3077 (0.36%) elective cases. Urgent cholecystectomy took 20 min longer than elective surgery (median 74 versus 52 min). No relevant difference in conversion rate was observed when urgent cholecystectomy was performed within 2 days, between 2 and 4 days, or greater than 4 days from admission (P = 0.197). Median total hospital stay was 4 days. CONCLUSION: Urgent laparoscopic cholecystectomy is safe and feasible in most patients with acute gall bladder disease. Surgery under the direct care of upper gastrointestinal specialist surgeons is associated with a low conversion rate, low complication rate, and short hospital stay. Timing of surgery has no effect on conversion rate or complication rate.

Hybrid laparoscopic versus fully robot-assisted minimally invasive esophagectomy: an international propensity-score matched analysis of perioperative outcome.

BACKGROUND: Currently, little is known regarding the optimal technique for the abdominal phase of RAMIE. The aim of this study was to investigate the outcome of robot-assisted minimally invasive esophagectomy (RAMIE) in both the abdominal and thoracic phase (full RAMIE) compared to laparoscopy during the abdominal phase (hybrid laparoscopic RAMIE). METHODS: This retrospective propensity-score matched analysis of the International Upper Gastrointestinal International Robotic Association (UGIRA) database included 807 RAMIE procedures with intrathoracic anastomosis between 2017 and 2021 from 23 centers. RESULTS: After propensity-score matching, 296 hybrid laparoscopic RAMIE patients were compared to 296 full RAMIE patients. Both groups were equal regarding intraoperative blood loss (median 200 ml versus 197 ml, p = 0.6967), operational time (mean 430.3 min versus 417.7 min, p = 0.1032), conversion rate during abdominal phase (2.4% versus 1.7%, p = 0.560), radical resection (R0) rate (95.6% versus 96.3%, p = 0.8526) and total lymph node yield (mean 30.4 versus 29.5, p = 0.3834). The hybrid laparoscopic RAMIE group showed higher rates of anastomotic leakage (28.0% versus 16.6%, p = 0.001) and Clavien Dindo grade 3a or higher (45.3% versus 26.0%, p < 0.001). The length of stay on intensive care unit (median 3 days versus 2 days, p = 0.0005) and in-hospital (median 15 days versus 12 days, p < 0.0001) were longer for the hybrid laparoscopic RAMIE group. CONCLUSIONS: Hybrid laparoscopic RAMIE and full RAMIE were oncologically equivalent with a potential decrease of postoperative complications and shorter (intensive care) stay after full RAMIE.

Learning curve for adoption of robot-assisted minimally invasive esophagectomy: a systematic review of oncological, clinical, and efficiency outcomes.

BACKGROUND: Robot-assisted minimally invasive esophagectomy (RAMIE) is gaining increasing popularity as an operative approach. Learning curves to achieve surgical competency in robotic-assisted techniques have shown significant variation in learning curve lengths and outcomes. This study aimed to summarize the current literature on learning curves for RAMIE. METHODS: A systematic review was conducted in line with PRISMA guidelines. Electronic databases PubMed, MEDLINE, and Cochrane Library were searched, and articles reporting on learning curves in RAMIE were identified and scrutinized. Studies were eligible if they reported changes in operative outcomes over time, or learning curves, for surgeons newly adopting RAMIE. RESULTS: Fifteen studies reporting on 1767 patients were included. Nine studies reported on surgeons with prior experience of robot-assisted surgery prior to adopting RAMIE, with only four studies outlining a specified RAMIE adoption pathway. Learning curves were most commonly analyzed using cumulative sum control chart (CUSUM) and were typically reported for lymph node yields and operative times, with significant variation in learning curve lengths (18-73 cases and 20-80 cases, respectively). Most studies reported adoption without significant impact on clinical outcomes such as anastomotic leak; significant learning curves were more likely in studies, which did not report a formal learning or adoption pathway. CONCLUSION: Reported RAMIE adoption phases are variable, with some authors suggesting significant impact to patients. With robust training through formal programmes or proctorship, however, others report RAMIE adoption without impact on clinical outcomes. A formalized adoption curriculum appears critical to prevent adverse effects on operative efficiency and patient care.

ESDE-MIE fellowship: a descriptive analysis of the first experiences.

Esophageal resection is a high-risk and technically demanding procedure, with a long proficiency-gain curve. The European Society Diseases of the Esophagus (ESDE)-Minimally Invasive Esophagectomy (MIE) training program was launched in 2018 for European surgeons willing to train and to begin a career undertaking MIE. The aim of this study was to evaluate the first experience of the ESDE-MIE fellowship and relate this to the initially predetermined core principles and objectives of the program. Between October 2021 and May 2022, the participating fellows, in collaboration with the ESDE Educational Committee, initiated a survey to assess the outcome and experience of these fellowships. Data from each individual fellowship were analysed and reported in a descriptive manner. Between 2018 and 2022, in total, five fellows have completed the ESDE-MIE fellowship program. Despite the COVID-19 outbreak just the year after its launch, predetermined clinical and research goals were achieved in all cases. Each of the fellows were able to assist in a median of 40 (IQR 27-69) MIE and/or Robot assisted (RA)MIE procedures, of a total median of 115 (IQR 83-123) attended Upper GI cases. After the fellowship, MIE has been fully adopted by the fellows who returned to their home institutions as Upper GI surgeons. The fellowship was concluded by the European Union of Medical Specialists (UEMS) Multidisciplinary Joint Committee (MJC) certification in Upper GI Surgery, which was successfully obtained by all who took part. Based on the experience of the first five fellows, the ESDE-MIE training fellowship meets with the expected needs even despite the COVID-19 outbreak in 2019. Furthermore, these fellows have returned home and integrated MIE into their independent surgical practice, affirming the ability of this program to train the next generation of MIE surgeons, even in the most challenging of circumstances.

Minimally Invasive Resection of Large Gastric Gastrointestinal Stromal Tumors.

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) frequently present as a large exophytically growing mass in the stomach, for which open partial gastrectomy is standard of care. The aim of this study was to evaluate the safety and feasibility of minimally invasive gastric resection (MIG) of large (>5 cm) GIST. METHODS: All patients who underwent MIG for a GIST in the University Medical Center Utrecht between 2011 and 2019 were included. Postoperative course and oncological outcomes were analyzed. RESULTS: Twenty-two patients with gastric GIST, median size 53 mm [20-175 mm], underwent MIG. In 4 patients, preoperative imatinib was given, aiming for tumor regression. Conversion from laparoscopic to open surgery occurred once (5%). An additional resection was performed in 3 patients (14%). In 2 patients (9%), an intraoperative complication occurred, consisting of tumor rupture in 1 patient (5%), and 6 patients (27%) developed postoperative complications. Median hospital stay was 5 days [3-7 days]. R0 resection was achieved in 96%. In 4 patients, adjuvant treatment was indicated. The median follow-up was 31 months, and 1-, 3- and 5-year disease-free survival were 94, 74 and 74%, respectively. One patient presented with local recurrence 2 years after the index resection. CONCLUSION: MIG for large GIST up to 17.5 cm in diameter is safe, feasible, and oncologically sound, allowing for a controlled resection and reduced patient morbidity.

T cell-mediated autoimmune disease due to low-affinity crossreactivity to common microbial peptides.

Environmental factors account for 75% of the risk of developing multiple sclerosis (MS). Numerous infections have been suspected as environmental disease triggers, but none of them has consistently been incriminated, and it is unclear how so many different infections may play a role. We show that a microbial peptide, common to several major classes of bacteria, can induce MS-like disease in humanized mice by crossreacting with a T cell receptor (TCR) that also recognizes a peptide from myelin basic protein, a candidate MS autoantigen. Structural analysis demonstrates this crossreactivity is due to structural mimicry of a binding hotspot shared by self and microbial antigens, rather than to degenerate TCR recognition. Biophysical studies reveal that the autoreactive TCR binding affinity is markedly lower for the microbial (mimicry) peptide than for the autoantigenic peptide. Thus, these data suggest a possible explanation for the difficulty in incriminating individual infections in the development of MS.

Three-arm robotic cholecystectomy: a novel, cost-effective method of delivering and learning robotic surgery in upper GI surgery.

Cholecystectomy is one of the commonest performed surgeries worldwide. With the introduction of robotic surgery, the numbers of robot-assisted cholecystectomies has risen over the past decade. Despite the proven use of this procedure as a training operation for those surgeons adopting robotics, the consumable cost of routine robotic cholecystectomy can be difficult to justify in the absence of evidence favouring or disputing this approach. Here, we describe a novel method for performing a robot-assisted cholecystectomy using a "three-arm" technique on the newer, 4th generation, da Vinci system. Whilst maintaining the ability to perform precision dissection, this method reduces the consumable cost by 46%. The initial series of 109 procedures proves this procedure to be safe, feasible, trainable and time efficient.

Intra-operative ultrasound assessment of the biliary tree during robotic cholecystectomy.

Image-guided assessment of bile ducts and associated anatomy during laparoscopic cholecystectomy can be achieved with intra-operative cholangiography (IOC) or laparoscopic ultrasound (LUS). Rates of robotically assisted cholecystectomy (RC) are increasing and herein we describe the technique of intra-corporeal biliary ultrasound during RC using the Da Vinci system. For intraoperative evaluation of the biliary tree during RC, in cases of suspected choledocholithiasis, the L51K Ultrasound Probe (Hitachi, Tokyo, Japan) is used. The extrahepatic biliary tree is scanned along its length, capitalising on the benefits of the full range of motion offered by the articulated robotic instruments and integrated ultrasonic image display using TileProTM software. Additionally, this technique avoids the additional time and efforts required to undock and re-dock the robot that would otherwise be required for selective IOC or LUS. The average time taken to perform a comprehensive evaluation of the biliary tree, from the hepatic ducts to the ampulla of Vater, is 164.1 s. This assessment is supplemented by Doppler ultrasound, which is used to fully delineate anatomy of the porta hepatis, and accurate measurements of the biliary tree and any ductal stones can be taken, allowing for contemporaneous decision making and management of ductal pathologies. Biliary tract ultrasound has been shown to be equal to IOC in its ability to diagnose choledocholithiasis, but with the additional benefits of being quicker and having higher completion rates. We have described our practice of using biliary ultrasound during robotically assisted cholecystectomy, which is ergonomically superior to LUS, accurate and reproducible.

Structure and functional analysis of the IGF-II/IGF2R interaction.

Embryonic development and normal growth require exquisite control of insulin-like growth factors (IGFs). In mammals the extracellular region of the cation-independent mannose-6-phosphate receptor has gained an IGF-II-binding function and is termed type II IGF receptor (IGF2R). IGF2R sequesters IGF-II; imbalances occur in cancers and IGF2R is implicated in tumour suppression. We report crystal structures of IGF2R domains 11-12, 11-12-13-14 and domains 11-12-13/IGF-II complex. A distinctive juxtaposition of these domains provides the IGF-II-binding unit, with domain 11 directly interacting with IGF-II and domain 13 modulating binding site flexibility. Our complex shows that Phe19 and Leu53 of IGF-II lock into a hydrophobic pocket unique to domain 11 of mammalian IGF2Rs. Mutagenesis analyses confirm this IGF-II 'binding-hotspot', revealing that IGF-binding proteins and IGF2R have converged on the same high-affinity site.

Predicting risk of underconfidence following maternity leave.

OBJECTIVE: To determine what factors affect paediatric trainee confidence on return to work after maternity leave. DESIGN: Information was collected anonymously via an online survey from trainees who had taken maternity leave. SETTING: The survey was distributed centrally to each UK deanery. MAIN OUTCOME MEASURES: Trainee confidence was rated retrospectively using self-assessment. RESULTS: 146 paediatric trainees from 12 out of 13 deaneries completed the survey. 96% of trainees experienced an initial lack of confidence, with 36% requiring 3 months or longer for their confidence to return. Prolonged lack of confidence was associated with longer time out of training, training stage, returning part-time, less frequent engagement with educational activities and lack of recognition by supervising consultant. CONCLUSION: We propose a scoring system using the above risk factors, the MoTHER score (Months out, Training stage, Hours worked on return, Educational activities, Recognition by consultant), which can be used to identify trainees who are at higher probability of experiencing reduced confidence on return to work.

The Predictive Value of Low Muscle Mass as Measured on CT Scans for Postoperative Complications and Mortality in Gastric Cancer Patients: A Systematic Review and Meta-Analysis.

Risk assessment is relevant to predict outcomes in patients with gastric cancer. This systematic review aimed to investigate the predictive value of low muscle mass for postoperative complications in gastric cancer patients. A systematic literature search was performed to identify all articles reporting on muscle mass as measured on computed tomography (CT) scans in patients with gastric cancer. After full text screening, 15 articles reporting on 4887 patients were included. Meta-analysis demonstrated that patients with low muscle mass had significantly higher odds of postoperative complications (odds ratio (OR): 2.09, 95% confidence interval (CI): 1.55-2.83) and severe postoperative complications (Clavien-Dindo grade ≥III, OR: 1.73, 95% CI: 1.14-2.63). Moreover, patients with low muscle mass had a significantly higher overall mortality (hazard ratio (HR): 1.81, 95% CI: 1.52-2.14) and disease-specific mortality (HR: 1.58, 95% CI: 1.36-1.84). In conclusion, assessment of muscle mass on CT scans is a potential relevant clinical tool for risk prediction in gastric cancer patients. Considering the heterogeneity in definitions applied for low muscle mass on CT scans in the included studies, a universal cutoff value of CT-based low muscle mass is required for more reliable conclusions.

Nucleotide binding affinities of the intact proton-translocating transhydrogenase from Escherichia coli.

Transhydrogenase (E.C. 1.6.1.1) couples the redox reaction between NAD(H) and NADP(H) to the transport of protons across a membrane. The enzyme is composed of three components. The dI and dIII components, which house the binding site for NAD(H) and NADP(H), respectively, are peripheral to the membrane, and dII spans the membrane. We have estimated dissociation constants (K(d) values) for NADPH (0.87 microM), NADP(+) (16 microM), NADH (50 microM), and NAD(+) (100-500 microM) for intact, detergent-dispersed transhydrogenase from Escherichia coli using micro-calorimetry. This is the first complete set of dissociation constants of the physiological nucleotides for any intact transhydrogenase. The K(d) values for NAD(+) and NADH are similar to those previously reported with isolated dI, but the K(d) values for NADP(+) and NADPH are much larger than those previously reported with isolated dIII. There is negative co-operativity between the binding sites of the intact, detergent-dispersed transhydrogenase when both nucleotides are reduced or both are oxidized.

Patients' and health-care professionals' awareness of cost: a multicentre survey.

Delivering cost-effective health care within the constraints of public funding is the goal of the NHS. In this study 248 health-care professionals and patients across six different hospitals were surveyed to ascertain their cost awareness. Cost awareness was poor across all groups.

An alternative conformation of the T-cell receptor alpha constant region.

Alphabeta T-cell receptors (TcRs) play a central role in cellular immune response. They are members of the Ig superfamily, with extracellular regions of the alpha and beta chains each comprising a V-type domain and a C-type domain. We have determined the ectodomain structure of an alphabeta TcR, which recognizes the autoantigen myelin basic protein. The 2.0-A-resolution structure reveals canonical main-chain conformations for the V(alpha), V(beta), and C(beta) domains, but the C(alpha) domain exhibits a main-chain conformation remarkably different from those previously reported for TcR crystal structures. The global IgC-like fold is maintained, but a piston-like rearrangement between BC and DE beta-turns results in beta-strand slippage. This substantial conformational change may represent a signaling intermediate. Our structure is the first example for the Ig fold of the increasingly recognized concept of "metamorphic proteins."

Some lessons from the systematic production and structural analysis of soluble (alpha)(beta) T-cell receptors.

T-cell receptors (TCRs) are membrane proteins which recognize antigens with high specificity forming the basis of the cellular immune response. The study of these receptors has been limited by the challenges in expressing sufficient quantities of stable soluble protein. Here we report our systematic approach for generating soluble, (alpha)(beta)-TCRs, for X-ray crystallographic studies. By using small-scale expression screens, novel standardized quality control mechanisms and crystallization and imaging robots we were able to add significantly to the current TCR structural database. Our success in crystallizing both isolated TCRs and Major histocompatibility complex (MHC):TCR complexes has provided us with sufficient data to develop focused crystallization screens, which have proved generically useful for the crystallization of this family of proteins and complexes.

Substitution of tyrosine 146 in the dI component of proton-translocating transhydrogenase leads to reversible dissociation of the active dimer into inactive monomers.

Transhydrogenase couples the redox reaction between NADH and NADP+ to proton translocation across a membrane. The protein has three components: dI binds NADH, dIII binds NADP+, and dII spans the membrane. Transhydrogenase is a "dimer" of two dI-dII-dIII "monomers"; x-ray structures suggested that the two catalytic sites alternate during turnover. Invariant Tyr146 in recombinant dI of Rhodospirillum rubrum transhydrogenase was substituted with Phe and Ala (proteins designated dI.Y146F and dI.Y146A, respectively). Analytical ultracentrifuge experiments and differential scanning calorimetry show that dI.Y146A more readily dissociates into monomers than wild-type dI. Analytical ultracentrifuge and Trp fluorescence experiments indicate that the dI.Y146A monomers bind NADH much more weakly than dimers. Wild-type dI and dI.Y146F reconstituted activity to dI-depleted membranes with similar characteristics. However, dI.Y146A reconstituted activity in its dimeric form but not in its monomeric form, this despite monomers retaining their native fold and binding to the dI-depleted membranes. It is suggested that transhydrogenase reconstructed with monomers of dI.Y146A is catalytically compromised, at least partly as a consequence of the lowered affinity for NADH, and this results from lost interactions between the nucleotide binding site and the protein beta-hairpin upon dissociation of the dI dimer. The importance of these interactions and their coupling to dI domain rotation in the mechanism of action of transhydrogenase is emphasized. Two peaks in the 1H NMR spectrum of wild-type dI are broadened in dI.Y146A and are tentatively assigned to S-methyl groups of Met resonances in the beta-hairpin, consistent with the segmental mobility of this feature in the structure.

The role of invariant amino acid residues at the hydride transfer site of proton-translocating transhydrogenase.

Transhydrogenase couples proton translocation across a membrane to hydride transfer between NADH and NADP+. Previous x-ray structures of complexes of the nucleotide-binding components of transhydrogenase ("dI2dIII1" complexes) indicate that the dihydronicotinamide ring of NADH can move from a distal position relative to the nicotinamide ring of NADP+ to a proximal position. The movement might be responsible for gating hydride transfer during proton translocation. We have mutated three invariant amino acids, Arg-127, Asp-135, and Ser-138, in the NAD(H)-binding site of Rhodospirillum rubrum transhydrogenase. In each mutant, turnover by the intact enzyme is strongly inhibited. Stopped-flow experiments using dI2dIII1 complexes show that inhibition results from a block in the steps associated with hydride transfer. Mutation of Asp-135 and Ser-138 had no effect on the binding affinity of either NAD+ or NADH, but mutation of Arg-127 led to much weaker binding of NADH and slightly weaker binding of NAD+. X-ray structures of dI2dIII1 complexes carrying the mutations showed that their effects were restricted to the locality of the bound NAD(H). The results are consistent with the suggestion that in wild-type protein movement of the Arg-127 side chain, and its hydrogen bonding to Asp-135 and Ser-138, stabilizes the dihydronicotinamide of NADH in the proximal position for hydride transfer.

Tryptophan phosphorescence spectroscopy reveals that a domain in the NAD(H)-binding component (dI) of transhydrogenase from Rhodospirillum rubrum has an extremely rigid and conformationally homogeneous protein core.

The characteristics of tryptophan phosphorescence from the NAD(H)-binding component (dI) component of Rhodospirillum rubrum transhydrogenase are described. This enzyme couples hydride transfer between NAD(H) and NADP(H) to proton translocation across a membrane and is only active as a dimer. Tryptophan phosphorescence spectroscopy is a sensitive technique for the detection of protein conformational changes and was used here to characterize dI under mechanistically relevant conditions. Our results indicate that the single tryptophan in dI, Trp-72, is embedded in a rigid, compact, and homogeneous protein matrix that efficiently suppresses collisional quenching processes and results in the longest triplet lifetime for Trp ever reported in a protein at ambient temperature (2.9 s). The protein matrix surrounding Trp-72 is extraordinarily rigid up to 50 degrees C. In all previous studies on Trp-containing proteins, changes in structure were reflected in a different triplet lifetime. In dI, the lifetime of Trp-72 phosphorescence was barely affected by protein dimerization, cofactor binding, complexation with the NADP(H)-binding component (dIII), or by the introduction of two amino acid substitutions at the hydride-transfer site. It is suggested that the rigidity and structural invariance of the protein domain (dI.1) housing this Trp residue are important to the mechanism of transhydrogenase: movement of dI.1 affects the width of a cleft which, in turn, regulates the positioning of bound nucleotides ready for hydride transfer. The unique protein core in dI may be a paradigm for the design of compact and stable de novo proteins.

Glutamine 132 in the NAD(H)-binding component of proton-translocating transhydrogenase tethers the nucleotides before hydride transfer.

Transhydrogenase, found in bacterial membranes and inner mitochondrial membranes of animal cells, couples the redox reaction between NAD(H) and NADP(H) to proton translocation. In this work, the invariant Gln132 in the NAD(H)-binding component (dI) of the Rhodospirillum rubrum transhydrogenase was substituted with Asn (to give dI.Q132N). Mixtures of the mutant protein and the NADP(H)-binding component (dIII) of the enzyme readily produced an asymmetric complex, (dI.Q132N)(2)dIII(1). The X-ray structure of the complex revealed specific changes in the interaction between bound nicotinamide nucleotides and the protein at the hydride transfer site. The first-order rate constant of the redox reaction between nucleotides bound to (dI.Q132N)(2)dIII(1) was <1% of that for the wild-type complex, and the deuterium isotope effect was significantly decreased. The nucleotide binding properties of the dI component in the complex were asymmetrically affected by the Gln-to-Asn mutation. In intact, membrane-bound transhydrogenase, the substitution completely abolished all catalytic activity. The results suggest that Gln132 in the wild-type enzyme behaves as a "tether" or a "tie" in the mutual positioning of the (dihydro)nicotinamide rings of NAD(H) and NADP(H) for hydride transfer during the conformational changes that are coupled to the translocation of protons across the membrane. This ensures that hydride transfer is properly gated and does not take place in the absence of proton translocation.