bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis of thioflavin T and other fluorescent dyes for fluorescent staining ofBacillus subtilisvegetative cell, sporulating cell, and mature spore
Authors: Kuwana Ritsuko , Yamazawa Ryuji , Ito Kiyoshi , Takamatsu Hiromu
Published: December 2022

Thioflavin T, a cationic benzothiazole dye, is typically used to detect amyloid fibrils. In this study, we analyzed the staining properties of Bacillus subtilis cells using several fluorescent dyes, including thioflavin T analogs, 2-(4ʹ-methylaminophenyl) benzothiazole (BTA-1), and 2-(4-aminophenyl) benzothiazole (APBT). Thioflavin T stained vegetative cells in the early log phase and outer layer structures of forespores and mature spores. The inner parts of forespores and heat-killed mature spores were also stained with thioflavin T. Congo red, auramine O, and rhodamine B stained forespores and mature spores similar to thioflavin T. In contrast, APBT and BTA-1 fluorescence was detected in the outer layers of vegetative cells, mother cells, forespores, and mature spores, indicating that they bind to the cell membrane and/or cell wall. The combination of the fluorescent dyes used in this study will help analyze morphogenetic processes during the sporulation and the damage mechanisms of vegetative cells and spores.
Single-cell RNA sequencing analyses: interference by the genes that encode the B-cell and T-cell receptors
Authors: Sundell Timothy , Grimstad Kristoffer , Camponeschi Alessandro , Tilevik Andreas , Gjertsson Inger , Mårtensson Inga-Lill
Published: December 2022

B and T cells are integral parts of the immune system and are implicated in many diseases, e.g. autoimmunity. Towards understanding the biology of B and T cells and subsets thereof, their transcriptomes can be analyzed using single-cell RNA sequencing. In some studies, the V(D)J transcripts encoding the variable regions of the B- and T-cell antigen receptors have been removed before the analyses. However, a systematic analysis of the effects of including versus excluding these genes is currently lacking. We have investigated the effects of these transcripts on unsupervised clustering and down-stream analyses of single-cell RNA sequencing data from B and T cells. We found that exclusion of the B−/T-cell receptor genes prior to unsupervised clustering resulted in clusters that represented biologically meaningful subsets, such as subsets of memory B and memory T cells. Furthermore, pseudo-time and trajectory inference analyses of early B-lineage cells resulted in a developmental pathway from progenitor to immature B cells. In contrast, when the B−/T-cell receptor genes were not removed, with the PCs used for clustering consisting of up to 70% V-genes, this resulted in some clusters being defined exclusively by V-gene segments. These did not represent biologically meaningful subsets; for instance in the early B-lineage cells, these clusters contained cells representing all developmental stages. Thus, in studies of B and T cells, to derive biologically meaningful results, it is imperative to remove the gene sequences that encode B- and T-cell receptors.
benchdamic: benchmarking of differential abundance methods for microbiome data
Authors: Calgaro Matteo , Romualdi Chiara , Risso Davide , Vitulo Nicola
Published: December 2022

Recently, an increasing number of methodological approaches have been proposed to tackle the complexity of metagenomics and microbiome data. In this scenario, reproducibility and replicability have become two critical issues, and the development of computational frameworks for the comparative evaluations of such methods is of utmost importance. Here, we present benchdamic, a Bioconductor package to benchmark methods for the identification of differentially abundant taxa.

Availability and implementation

benchdamic is available as an open-source R package through the Bioconductor project at https://bioconductor.org/packages/benchdamic/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Interactive network-based clustering and investigation of multimorbidity association matrices with associationSubgraphs
Authors: Strayer Nick , Zhang Siwei , Yao Lydia , Vessels Tess , Bejan Cosmin A , Hsi Ryan S , Shirey-Rice Jana K , Balko Justin M , Johnson Douglas B , Phillips Elizabeth J , Bick Alex , Edwards Todd L , Velez Edwards Digna R , Pulley Jill M , Wells Quinn S , Savona Michael R , Cox Nancy J , Roden Dan M , Ruderfer Douglas M , Xu Yaomin
Published: December 2022

Motivation

Making sense of networked multivariate association patterns is vitally important to many areas of high-dimensional analysis. Unfortunately, as the data-space dimensions grow, the number of association pairs increases in O(n2); this means that traditional visualizations such as heatmaps quickly become too complicated to parse effectively.

Results

Here, we present associationSubgraphs: a new interactive visualization method to quickly and intuitively explore high-dimensional association datasets using network percolation and clustering. The goal is to provide an efficient investigation of association subgraphs, each containing a subset of variables with stronger and more frequent associations among themselves than the remaining variables outside the subset, by showing the entire clustering dynamics and providing subgraphs under all possible cutoff values at once. Particularly, we apply associationSubgraphs to a phenome-wide multimorbidity association matrix generated from an electronic health record and provide an online, interactive demonstration for exploring multimorbidity subgraphs.

Availability and implementation

An R package implementing both the algorithm and visualization components of associationSubgraphs is available at https://github.com/tbilab/associationsubgraphs. Online documentation is available at https://prod.tbilab.org/associationsubgraphs_info/. A demo using a multimorbidity association matrix is available at https://prod.tbilab.org/associationsubgraphs-example/.
bmVAE: a variational autoencoder method for clustering single-cell mutation data
Authors: Yan Jiaqian , Ma Ming , Yu Zhenhua
Published: December 2022

Motivation

Genetic intra-tumor heterogeneity (ITH) characterizes the differences in genomic variations between tumor clones, and accurately unmasking ITH is important for personalized cancer therapy. Single-cell DNA sequencing now emerges as a powerful means for deciphering underlying ITH based on point mutations of single cells. However, detecting tumor clones from single-cell mutation data remains challenging due to the error-prone and discrete nature of the data.

Results

We introduce bmVAE, a bioinformatics tool for learning low-dimensional latent representation of single cell based on a variational autoencoder and then clustering cells into subpopulations in the latent space. bmVAE takes single-cell binary mutation data as inputs, and outputs inferred cell subpopulations as well as their genotypes. To achieve this, the bmVAE framework is designed to consist of three modules including dimensionality reduction, cell clustering and genotype estimation. We assess the method on various synthetic datasets where different factors including false negative rate, data size and data heterogeneity are considered in simulation, and further demonstrate its effectiveness on two real datasets. The results suggest bmVAE is highly effective in reasoning ITH, and performs competitive to existing methods.

Availability and implementation

bmVAE is freely available at https://github.com/zhyu-lab/bmvae.

Supplementary information

Supplementary data are available at Bioinformatics online.
Invasive Species Policy Must Embrace a Changing Climate
Authors: Bradley Bethany A , Beaury Evelyn M , Fusco Emily J , Lopez Bianca E
Published: December 2022

With increasing impacts of climate change observed across ecosystems, there is an urgent need to consider climate change in all future environmental policy. But existing policy and management might be slow to respond to this challenge, leading to missed opportunities to incorporate climate change into practice. Furthermore, invasive species threats continue to rise and interact with climate change—exacerbating negative impacts. Enabling natural resource managers and individuals to be proactive about climate-driven invasive species threats creates a win–win for conservation. Recommendations include expanding opportunities for information sharing across borders, supporting proactive screening and regulation of high-risk species on the horizon, and incentivizing individual actions that reduce ecological impacts. In addition, invasive species risk should be considered when crafting climate mitigation and adaptation policy to reduce compounding stressors on ecosystems. As we develop much-needed tools to reduce harm, policy and management must consider the combined threats of invasions and climate change.
Causes, Responses, and Implications of Anthropogenic versus Natural Flow Intermittence in River Networks
Authors: Datry Thibault , Truchy Amélie , Olden Julian D , Busch Michelle H , Stubbington Rachel , Dodds Walter K , Zipper Sam , Yu Songyan , Messager Mathis L , Tonkin Jonathan D , Kaiser Kendra E , Hammond John C , Moody Eric K , Burrows Ryan M , Sarremejane Romain , DelVecchia Amanda G , Fork Megan L , Little Chelsea J , Walker Richard H , Walters Annika W , Allen Daniel
Published: December 2022

Rivers that do not flow year-round are the predominant type of running waters on Earth. Despite a burgeoning literature on natural flow intermittence (NFI), knowledge about the hydrological causes and ecological effects of human-induced, anthropogenic flow intermittence (AFI) remains limited. NFI and AFI could generate contrasting hydrological and biological responses in rivers because of distinct underlying causes of drying and evolutionary adaptations of their biota. We first review the causes of AFI and show how different anthropogenic drivers alter the timing, frequency and duration of drying, compared with NFI. Second, we evaluate the possible differences in biodiversity responses, ecological functions, and ecosystem services between NFI and AFI. Last, we outline knowledge gaps and management needs related to AFI. Because of the distinct hydrologic characteristics and ecological impacts of AFI, ignoring the distinction between NFI and AFI could undermine management of intermittent rivers and ephemeral streams and exacerbate risks to the ecosystems and societies downstream.
BS O02 Long-term survival after sleeve gastrectomy versus gastric bypass in a bi-national cohort study
Authors: Markar Sheraz , Holmberg Dag , Santoni Giola , Kauppila Joonas , Lagergren Jesper
Published: December 2022

Background

Bariatric surgery prolongs life expectancy in severely obese individuals, but it is uncertain which of the two dominating bariatric procedures, sleeve gastrectomy or gastric bypass, offers the best long-term survival.

Methods

This was a population-based cohort study comparing primary laparoscopic sleeve gastrectomy to gastric bypass for obesity in Sweden and Finland between January 1, 2007 and December 31, 2020. The risk of all-cause mortality was calculated using multivariable Cox regression, providing hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, sex, hypertension, diabetes, Charlson comorbidity index, country, and calendar year.

Results

Among 61,503 patients (median age 42 years; 75.4% women), who contributed 415,712 person-years at risk (mean 6.8 person-years), 1,571 (2.6%) died during follow-up. Compared to patients who underwent gastric bypass (n=51,891, 84.4%), the sleeve gastrectomy group (n=9,612, 15.6%) had similar all-cause mortality during the entire study period (HR=0.98, 95% CI 0.81–1.20), but decreased all-cause mortality in more recent years (HR=0.72, 95% CI 0.54–0.97, from 2014 onwards). Diabetes interacted statistically significantly with the type of bariatric surgery, with higher all-cause mortality after sleeve gastrectomy than gastric bypass (HR=1.54, 95% CI 1.06–2.24).

Conclusions

The overall survival following sleeve gastrectomy seems to compare well with gastric bypass, and may even be better during recent years. A tailored surgical approach in relation to patients’ diabetes status may optimize survival in patients selected for bariatric surgery, i.e. sleeve gastrectomy for non-diabetic patients and gastric bypass for patients with diabetes.
HPB O06 Developing a patient-derived model of cholangiocarcinoma using Precision Cut Tissue Slices (PCTS)
Authors: Gilbert Timothy , Randle Laura , Diaz-Nieto Rafael , Jones Robert , Fenwick Stephen , Goldring Christopher , Malik Hassan
Published: December 2022

Background

Cholangiocarcinoma (CCA) is an aggressive malignancy with increasing incidence and persistently poor prognosis. None surgical treatment options for these patients are limited and a preponderance to chemoresistance means the benefits from chemotherapy are modest. The development of new targeted therapeutic strategies that prolong survival and reduce the risk of recurrence post-surgery are required. Accurate models that recapitulate tumour biology are essential to test and identify these novel therapies. Precision-cut tissue slices (PCTS) are patient-derived whole tissue explants that can be cultured ex-vivo. By retaining all aspects of the tumour micro-environment they recapitulate critical aspects of cancer biology, a significant advantage over 3D organoid culture. Our aim is to establish the use of the PCTS technique in CCA as the first step towards creating a patient-derived model of cholangiocarcinoma for use as a drug discovery platform.

Methods

CCA tissue samples and matched healthy liver tissue were collected from the operating theatre during surgical resection from fully consented patients. Multiple tissue slices (250μm, 5mm diameter) were prepared using a Krumdiek tissue slicer. Tissue slices were randomly incubated in triplicate and cultured for 0–15 days in 24 well plates. Tissue perfusion and air-liquid interface was maintained using Millipore well inserts. Tissue viability was determined at timepoints utilising MTS and ATP viability assays along with histological markers of proliferation (Ki-67) and apoptosis (cleaved-caspase 3). Maintenance of tissue morphology and phenotype during culture was confirmed on histological H&E staining and by staining of tumour specific markers (e.g CK19) on IHC and Western Blot.

Results

Thus far n=4 patients have had PCTS generated (3=pCCA 1=iCCA) from their tumour along with matched healthy liver. Following optimisation of the experimental protocol viability of the matched normal and tumour tissue slices can be maintained for upto 10 days, as assessed via in-situ MTS assay. Histological assessment of tissue slices harvested at day 0, 1,3,7 of culture shows the morphological and phenotypic structures of the source tumour to be maintained during ex-vivo culture. Viability of the tumour cells was additionally confirmed through the absence of cleave-caspase 3 markers of apoptosis on IHC staining.

Conclusions

This initial work has shown it is feasible to generate PCTS of CCA from resected surgical specimens with good viability. Further work is still required to ensure that our model retains a robust recapitulation of the in-vivo tumour including examination of the gene-expression profile. However, these initial results provide encouragement for the use of PCTS as a patient-derived model for drug discovery in CCA.
HPB V08 Fluorescence Image Guidance (FIG) in minimally invasive liver surgery- can it help identify deep margins?
Authors: Karmarkar Rahi , Tanase Andrei , Aroori Somaiah
Published: December 2022

Background

Despite recent advances in imaging modalities and surgical techniques in liver resection, the rate of R1 resection in liver tumours is still high. Currently, liver surgeons plan the type of liver resection based on information gathered from pre-operative cross-sectional imaging, intraoperative naked eye examination/palpation, and intra-operative ultrasound (IOUS) examination. Naked eye examination and palpation help identify superficially located tumours; however, they do not help localise deeply seated small tumours or accurately mark tumour margins. Moreover, the lack of tactile feedback in the case of laparoscopic liver surgery makes tumour identification further difficult. Currently, IOUS is the most sensitive test for detecting liver tumours – in both open and laparoscopic liver surgery. However, it does not give a real-time visual clue on transection margins. Identification and marking of the deep margin of the tumour are not possible with IOUS. We describe the use of FIG using indocyanine green (ICG) dye in localisation and identification of deep margins of a segment seven liver metastasis.

Methods

We present a video demonstration of the use of FIG in the identification of deep resection margins of a segment seven tumour in a 41 year-old female patient. Initially, the tumour was not visible to the naked eye owing to its location, which made the identification of the tumour and its margins with IOUS challenging. We can see in the video how ICG identified the tumour readily and helped identify the resection margins, especially the deep margin, which was challenging to identify with IOUS. The histology report confirmed that all margins were free of tumours.

Results

We found that FIG is a robust, objective, real-time navigation tool that can overcome some of the shortfalls associated with and help accurately identify tumour resection margins. When used along with IOUS, we believe that FIG using ICG can potentially reduce R1 resection rates in liver tumours.

Conclusions

We found that FIG is a robust, objective, real-time navigation tool that can overcome some of the shortfalls associated with and help accurately identify tumour resection margins. When used along with IOUS, we believe that FIG using ICG can potentially reduce R1 resection rates in liver tumours.
OGBN O01 Laparoscopic large hiatus hernia repair with mesh versus suture: a systematic review and meta-analysis
Authors: Rajkomar Kheman , Wong Michael , Gall Lewis , MacKay Colin , MacDonald Andrew , Forshaw Matthew , Craig Carol
Published: December 2022

Background

Whilst the use of laparoscopy in the repair of large hiatus hernia (LHH) has become mainstream, the prevention of post operative hernia recurrence and other adverse events has remained a challenge. Mesh reinforcement of suture cruroplasty has been considered as a potential solution. However the paucity of well constructed and powered randomised control trials (RCT) with long term followup makes an assessment of its real impact difficult.

The aim of this review is to evaluate the effectiveness of mesh reinforcement of LHH repair, with regards to postoperative outcomes.

Methods

A systematic search of articles was conducted in PubMed, Medline and Embase using the PRISMA guidelines. RCTs and observational studies (OS) comparing recurrences and reoperations in those patients with LHH (>30% stomach in chest, >5cm hiatal defect, hiatal surface area >10 mm2) repair who had mesh vs no mesh were assessed quantitatively. The impact of mesh on significant intraoperative/postoperative surgical complications and mortality were qualitatively assessed.

Results

Pooled data included five RCTs and fourteen OS with 1670 patients (824 with no mesh, 846 with mesh). There was a significant reduction in total recurrence rate with mesh (OR 0.44, 95% CI 0.25 to 0.80, p = 0.007). Mesh use did not cause significant reduction in recurrences >2cm (OR 0.94, 95% CI 0.52 to 1.67, p = 0.83) or significant reduction in reoperation rates (OR 0.64, 95% CI 0.39 to 1.07, p = 0.09). None of the meshes were found to significantly reduce recurrence or reoperation rate on subgroup analysis, although the number of studies using a single mesh type was limited. Major morbidity rates associated with LHH repair included mesh erosion with foregut resection (from synthetic mesh) and esophageal perforation and were 0.71% and 0.36% respectively. An overall mortality rate of 0.3% was found in the pooled patients.

Conclusions

Mesh reinforcement in LHH is protective against total recurrence. However there is no significant reduction in large recurrences (>2cm) or reoperation rate. If synthetic mesh is to be used patients need to be informed of the risk of mesh erosion.
OGBN O04 Upper Gastrointestinal Training in the UK & Ireland – a Roux Group Study
Authors: Robinson David , Zakeri Roxanna , Laing Richard , Choh Clarisa , Abouelazayem Mohamed , Askari Alan , Bradley Alison , Brown Leo , Currie Andrew , Elmasry Mohamed , Evans Richard , Gall Tamara , Jerome Ellen , Raftery Nicola , Samuel Maria , Spiers Harry , Chan Benjamin
Published: December 2022

Background

Surgical training programmes in the United Kingdom and Ireland (UK&I) are in a transition period evidenced by new surgical curricula. This study is the first to collate the opinions of UK&I trainee and consultant surgeons regarding the current Upper Gastrointestinal (UGI) training model.

Methods

A questionnaire was developed and distributed via national UGI societies and the social media platform, Twitter. A total of 241 responses were received with all UK&I regions represented.

Results

The median time to Certificate of Completion of Training (CCT) of 13 years was considered reasonable (50.2%), however the majority (67.2%) found training to be unfocused. The suggested targets for publications, presentations and audits were 3–5 (trainee vs consultant <3 vs 3–5, p<0.001), <3 (<3 vs 3–5, p=0.002) and 3–5 (<3 vs 3–5, p<0.001) respectively. The majority (61.9%) considered a higher academic degree advantageous but felt it should not be compulsory. Interestingly, most respondents (63.5%) had or planned to undertake one. Crucially, there were geographical discrepancies in access to training, particularly in bariatrics, robotic surgery, and endoscopy. Proficiency in diagnostic endoscopy was deemed essential for CCT and consultant practice (81.7% and 67.6% respectively). The current index UGI operative requirements were felt to be achievable (87.6%) but inadequate for day one consultant practice (74.7%), an opinion shared by both the trainee and consultant groups (p=0.662). Reassuringly, most respondents (76.3%) deemed there to be a role for on-the-job operative training following consultant appointment. Post-CCT fellowships were not considered necessary for consultant appointment, however the majority (73.6%) again recognised its advantage.

Conclusions

While variations were seen in the opinions of trainee and consultant surgeons, the current CCT requirements as outlined by the Joint Committee on Surgical Training are consistent with the overall perspective of the UGI community. Areas for improvement include flexibility in geographical working and provisions for endoscopy training, to ensure equal access.
OGBN V09 Laparoscopic Resection of Epiphrenic Diverticulum and Hellers Cardiomyotomy for achalasia
Authors: Frank Amy , Kostalas Marcos , Andrews Stuart
Published: December 2022

Background

Epiphrenic diverticula are a rare form of diverticulum located in the distal oesophagus. Symptoms are varied as patients may be asymptomatic or present acutely with dysphagia and regurgitation. This video presentation is a case report and discussion of a patient requiring laparoscopic resection of an epiphrenic diverticulum and Hellers cardiomyotomy for concurrent achalasia.

Methods

The case of a 58 year old man is presented, who attended as an emergency with severe malnutrition and aspiration pneumonia secondary to dysphagia. Initial investigations included an upper GI endoscopy, barium swallow and CT scan which demonstrated a large oesophageal diverticulum and undiagnosed achalasia.

Results

The video presentation explores the operative technique used during this case in order to resect the epiphrenic diverticulum and perform a subsequent Hellers cardiomyotomy for achalasia.

Conclusions

Operative intervention was successful and the patient was discharged on day 2 post-operatively with no further complications. This video presentation stimulates further discussion regarding the management and operative technique utilised in epiphrenic diverticulae.
OGC O06 An international cohort study of prognosis associated with pathologically complete response following neoadjuvant chemotherapy vs. chemoradiotherapy of surgical treated esophageal adenocarcinoma
Authors: Markar Sheraz , Cools-Lartigue Jonathan , Mueller Carmen , Hofstetter Wayne , Nilsson Magnus , Ilonen Ilka , Soderstrom Henna , Rasanen Jari , Gisbertz Suzanne , Hanna George , Elliott Jessie , Reynolds John , Kisiel Aaron , Griffiths Ewen , van Berge Henegouwen Mark , Ferri Lorenzo
Published: December 2022

Background

Objective: To compare overall (OS) and recurrence-free survival (RFS) in esophageal adenocarcinoma patients with a complete pathological response (pCR) following neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy (nCRT).

Background

In the absence of survival differences in several prior studies comparing nCT with nCRT, the higher rate of pCR after nCRT has been suggested as reason to prefer this modality over nCT.

Methods

An international cohort study included data from 8 high-volume centers. Inclusion criteria was patients with esophageal adenocarcinoma, between 2008 and 2018, who had a pCR following nCT or nCRT. Univariate analysis was used to compare demographic factors, and Kaplan-Meier survival analysis used to compare 5-year OS and RFS between groups.

Results

465 patients with pCR following neoadjuvant treatment were included; 132 received nCT and 333 received nCRT. There was no statistically significant difference in 5-year OS between groups (78.8% (nCT) vs. 65.5% (nCRT), p=0.099), with a similar result demonstrated in multivariate analysis (HR=1.19, 95%CI 0.77 to 1.84). 5-year RFS was significantly reduced in patients with a pCR following neoadjuvant chemoradiotherapy (75.3% (nCRT) vs. 87.1% (nCT), p=0.026). Multivariate analysis confirmed nCRT was associated with a poorer 5-year RFS (HR=1.70, 95%CI 1.22 to 2.99). nCRT associated with a significantly greater prevalence of 5-year distant recurrence (Odds ratio = 2.50, 95%CI 1.25–4.99).

Conclusions

The results of this international cohort study show that the prognosis of pCR following different neoadjuvant regimes differs, bringing into question the validity of this measure as an oncological surrogate when comparing neoadjuvant treatment schemes for esophageal adenocarcinoma.
OGBN P07 Fenestrating vs Reconstituting - Outcomes following 170 subtotal cholecystectomies
Authors: Thomas Christophe , Wintrip Dorothy , Horgan Liam , Brown Jamie
Published: December 2022

Background

Laparoscopic subtotal cholecystectomy (LSC) is a recognised option when the “critical view” cannot be safely delineated. It carries a high morbidity rate with increased frequencies of a bile leak occurring however reducing the risk of bile duct injury. LSC can be classified into fenestrating or reconstituting cholecystectomy and surgical practice varies as reconstituting is considered to be more complex. Our aim of the study was to look at LSC with respect to the techniques used, complications and the overall outcomes.

Methods

All adult patients undergoing LSC between January 2015 – December 2021 were retrospectively identified on our electronic database. Data gathered included: Patient demographics, previous acute biliary presentations, operative details/technique, length of stay (LOS), 30-complications, 30-day mortality, readmissions and follow up investigations/procedures. Descriptive statistics, Chi squared, and relative risk were used to analyse results.

Results

170 patients underwent LSC in the study period with the rate increasing most years. Median age was 67 with 86:84 Female to Male ratio. Rates varied drastically between different surgeons from 0.1% to 19% compared to total number of laparoscopic cholecystectomies. 130 (76%) were performed in the acute setting and 63/170 (37%) had previous acute biliary presentations. Median LOS was 5 days. Most patients had Fenistrating LSC (155 [67.6%] vs. 55 [32.3%]).

80 (47%) patients had complications. These were graded by Clavin-dindo grade: I – 3 (3.7%); II – 34 (42.5%); IIIa – 26 (32.5%); IIIb – 16 (20%) and IV – 1 (1.25%). The most frequent complication was bile leak; 60 (35.2%) followed by collection 8 (4.7%). Other notable complications were pancreatitis; 3 (1.7%), AKI; 2 (1%), bile duct injury; 1 (0.5%) and duodenal injury; 1 (0.5%). 16 (9.4%) patients had returns to theatre, 14 (8.2%) patients had readmissions and 35 (20.5%) had multiple attendances to the day unit following discharge. Further analysis demonstrated that that fenestrated technique was associated with a greater risk of bile leak (p<0.01 RR 2.1 [95% C.I. 1.3–6.3]) and post operative ERCP (p<0.01 RR 3.8 [95% C.I. 1.6–14]). 2 (1.1%) patients required completion cholecystectomy, one form each technique.

Conclusions

We present one of the largest single unit datasets on LSC, and the 2nd largest from UK population. Our rate of LSC is increasing, likely as a safe alternative to open conversion, with large surgeon variability. The majority are performed in the acute setting with the fenestrated technique. We have demonstrated however that LSC has a high morbidity, both in reoperation/reintervention rate, readmission and complications accompanied by high follow-up requirement. Despite fenestrated being the favoured technique in our unit we have shown that it has poorer outcomes. Our data would suggest that if LSC is to be performed then the reconstituted technique should be used if possible.
OGBN P09 Sharing the experience of the use of Spyglass DS - guided electrohydraulic lithotripsy (SG-EHL) in the treatment of large gallstone causing Bouveret syndrome
Authors: Kouli Tasnim , Gresz Rahel , Abdelwahab Sameh , Shaalan Ramy , Zino Samer
Published: December 2022

Background

Less than 1% of intestinal obstruction is accounted for by gallstone ileus. Gallstone ileus is a mechanical intestinal obstruction resulting from gallstone impaction within the gastrointestinal tract. Under 3% of gallstone ileus are caused by gallstone impaction in the duodenum or pylorus, which can give rise to a gastric outlet obstruction, described by Bouveret in 1896.

Surgical intervention involves the removal of the stone by either a gastrotomy or duodenotomy, which is associated with significant morbidity. Advancement in endoscopic techniques, allows for more complex procedures, therefore, reducing the need for a surgical intervention and its accompanying morbidity.

This abstract presents a rare case of a large gallstone (22mm×34mm) partially impacted in the duodenum of a 92-year-old female, which was treated with the Spyglass DS-guided electrohydraulic lithotripsy (DS-EHL).

Methods

A 92-year-old female with a previous history of gallstone ileus was treated by surgical intervention. The patient continued to complain of abdominal discomfort and occasional vomiting.

A CT scan revealed a fistulous communication to the duodenal bulb, containing a large gall stone (22mm x34 mm). After consultation with the patient, an initial assessment with the use of standard endoscopy under general anaesthesia confirmed the visualisation of a portion of the gallstone in the duodenum, hanging through a well-established cholecysto-dudenal fistula.

SPyglass DS - guided lithotripsy (SG-EHL) was used in the treatment of the large gallstone.

Results

Electrohydraulic lithotripsy (EHL) was attempted through the standard gastroscope, but we were unable to secure a safe position to target the stone. Therefore, a side view duodenoscope was used along with the SpyGlass DS to obtain good visualisation and stable access to target the stone with the EHL. The Spyglass guided electrohydraulic lithotripsy (SG-EHL) was used to fragment the stone. Despite consuming four EHL wires and using higher settings, we only managed to break the shell of the stone, reducing its size by approximately 3mm all around. The laser was not available at the time; therefore, the procedure was concluded. The patient had an uneventful recovery and was discharged home. No further symptoms were recorded by patient on follow up 5 months later.

Conclusions

Endoscopic management of an impacted gallstone causing gastric outlet obstruction is found to be safe and carries less morbidity than the traditional surgical approach. Therefore, it should be considered for being the procedure of choice to treat patients with Bouveret syndrome. Laser lithotripsy should be available on standby for cases that involve stones that are harder to break.
OGBN P17 Preoperative scoring system in predicting difficulty in laparoscopic cholecystectomy
Authors: Adnan Naqqash
Published: December 2022

Background

For a long time now, laparoscopic cholecystectomy (LC) has been the gold standard treatment for gallstone disease. Having said that, approximately 2–15% of attempted LCs have to be converted to an open procedure due to various difficulties faced while performing the procedure. This study has been structured and planned taking into account the various difficult situations a laparoscopic surgeon faces during laparoscopic cholecystectomy and assigns an objective outlook to the difficulty in the form of a difficulty score. The main objective of the study is to evaluate a scoring system in predicting difficulty in laparoscopic cholecystectomy.

Methods

Patients with symptomatic gallstone disease that were admitted in SU-1 of Holy family hospital during the above period were included in the study. For collection of data, a pre-tested questionnaire was used after taking informed oral consent. On admission, one day before the surgery, preoperative points were allotted on basis of patient's history, examination, hematological (CBC), biochemical (LFTs) and ultrasound results. Preoperative scores up to 5 was summed up as easy, scores 6–10 as difficult, 11–16 as very difficult. Calculated sample size was 229. SPSS version 22 and WHO Anthro calculator version 3.2.2 were used for data entry and analysis

Results

Among 230 patients that were included in the study, 188 were female and 42 were male. Various risk factors were found to have significant positive correlation with intraoperative difficulty during cholecystectomy. These are: Previous episodes of cholecystitis and pancreatitis (p=0.00), ERCP (p=0.00), tenderness in right hypochondrium (p=0.002), hepatitis serology (p=0.02), and Total Leukocyte Count (p=0.006). Whereas the following factors had insignificant relation with intraoperative difficult cholecystectomy: ALT and ALP (p>0.05, p=0.06 and 0.26 respectively) and hepatitis serology (p=0.406). A significant correlation was found between preoperative and intraoperative scores of the patients (p=0.003) indicating that preoperative assessment of various risk factors can predict the level of difficulty of cholecystectomy and its conversion to open cholecystectomy.

Conclusions

We may conclude that the scoring system evaluated in our study is a sturdy, reliable and useful benchmark to predict difficult cases. Preoperative prediction of the risk factors of conversion or difficulty of operation is an important point for operative planning and the high-risk patients may be informed accordingly.
OGBN P18 Laparoscopic Deroofing of a Liver Cyst
Authors: Bradley Alison , Kostalas Marcos , Bowling Kirk , Andrews Stuart
Published: December 2022

Background

Laparoscopic deroofing is considered to be part of standard practice for simple nonparasitic liver cysts.

Methods

This “how to” video demonstrates an approach to the laparoscopic deroofing of a large, nonparasitic liver cyst. After the placement of umbilical, epigastric and a working right upper quadrant port, the cyst is aspirated. This allows easier handling of the cyst. A cystostomy is then created and a LOTUS or Harmonic scalpel is used to cut thru the cyst wall.Further suctioning of the cyst contents allows the cyst to collapse which facilitates handling of the tissue. Complete resection of the cyst can be achieved by dissecting close to the cyst wall which is then placed into an endobag prior to removal. It is important to ensure good haemostasis at the liver. Omentum may be placed in larger cavities to reduce dead space and prevent fluid collection.

Results

This patient made a good postoperative recovery and cytology and histology confirmed benign cyst.

Conclusions

This video demonstrates one approach to the laparoscopic deroofing of a large, simple, nonparasitic liver cyst.
EGS P03 Selective non-operative management of high grade splenic injuries is safe in both the short and long term
Authors: Curran Matthew , Lowe Aaron , Jamdar Saurabh
Published: December 2022

Background

Blunt and penetrating splenic injuries represent a significant component of the workload in major trauma centres in the UK. International guidelines recommend intervention for patients suffering high grade injuries. This single centre retrospective cohort study assessed current management of adults with splenic injuries, stratified by World Society of Emergency Surgery (WSES) classification, and compared this to the recommended management proposed by the WSES guidelines.

Methods

Patients admitted between April 2014 to January 2021 to a major trauma centre with splenic injuries were prospectively assessed. Data on AAST grade, WSES class, radiological imaging, definitive interventions performed, length of admission, follow-up imaging and short and long-term outcome were collected.

Results

143 patients with splenic injuries were admitted during the study period. 5 patients were excluded due to inadequate clinical information. 138 patients with splenic injury were analysed. 50 suffered WSES grade 1 injuries, 25 WSES grade 2, 18 WSES grade 3 and 45 WSES grade 4. Patients with WSES grade 3 and 4 injuries were managed as follows: conservative 13, angioembolisation 38 and splenectomy 12. Length of stay did not differ between groups. No patient undergoing non-operative management required salvage splenectomy. One patient undergoing angioembolisation required laparoscopic drainage of splenic abscess secondary to infarction. During the study period 4 patients died (2.7)%. The cause of death in each case was due to other injuries. Long term imaging follow up was organised in 31 patients undergoing angioembolisation. 30 patients (97%) had imaging features suggestive of perfused splenic tissue.

Conclusions

Conservative management of splenic injuries with the addition of angioembolisation for high grade injuries led to a splenectomy rate of less than 10% in this study. This strategy led to low morbidity with only one patient requiring subsequent intervention and no splenic injury related mortality. This study validates the increasing trend towards non-operative management for splenic injuries.
EGS P04 Transgastric drainage of oesophageal perforations: The largest case series
Authors: Lunt Adam , Ariyarathenam Arun , Chan David , Humphreys Lee , Sanders Grant , Wheatley Tim , Berrisford Richard
Published: December 2022

Background

Oesophageal perforation is associated with a high morbidity and mortality. Multiple operative and non-operative management strategies have been described. We first described the novel technique of transgastric drainage of oesophageal injuries in 2008. This has since been adopted across other units in the UK and Ireland. The technique exteriorises the site of the perforation by establishing vacuum drainage of the lumen of the oesophagus, whilst maintaining luminal patency and thereby encouraging healing by secondary intention. We present our 10 year experience with the largest case series in the literature.

Methods

A retrospective analysis was undertaken of all patients with oesophageal perforation treated with transgastric drainage, over the last 10 years, in our specialist unit.

Transgastric drainage was performed using a 36 Fr Chest drain inserted through the stomach, into the oesophageal lumen above the proximal extent of the perforation. This was endoscopically performed with either laparoscopic or open guidance. Gastropexy was performed. Continuous suction of -10cm water was applied to the drain until no leak was noted. Mediastinal decontamination and drainage was performed as needed. Nutrition was provided by total parenteral nutrition or feeding jejunostomy.

Results

35 patients were treated with transgastric drain. 68% (n=24) were male. Median age was 67 (26–84). 60% (n=21) being spontaneous perforations and 31% (n=11) were iatrogenic. Inpatient and 30-day mortality was 14% (n=5). Among patients who survived, the median length to resolution of leak on imaging was 34.5 days (6–80). Median length of stay was 39.5 (16–84) days.

Conclusions

Transgastric drainage can be successfully used to treat oesophageal perforations of varied lengths. The mortality rate of 14% compares favourably with other methods of management for oesophageal perforation.
EGS P09 An Ambulatory General Surgical Service, Reducing the On-Call Burden and Improving Patient Experience
Authors: Boag Katie , Bradley Alex , Toogood Giles , Peckham-Cooper Adam
Published: December 2022

Background

The management of acute General Surgical patients is dramatically changing with the emergence of Emergency General Surgery departments. The trend is moving towards consultant-led services, and managing patients on ambulatory pathways. This prospective study aims to demonstrate the impact of a consultant-led ambulatory surgical clinic and primary care telephone access on the acute surgical take in a busy tertiary hospital.

Methods

Data was collected from March 2021-March 2022. Patients were included via the primary care access line, as well as patient attendances either via surgical assessment unit (SAU), or ambulatory surgical clinic (ASC). Their pathways were recorded i.e. admit, discharge, further ambulatory investigation, listed for surgery.

Results

Consultants took 6,948 calls from primary care from March 2021–22. 43.7% of patients were given an appointment for ASC, 37.3% admitted to SAU, 3.5% directed to ED, and 15.5% given advice or redirected elsewhere. 54.6% of those seen in ASC were discharged without further follow up, the other 45.4% were either admitted, followed up or added to a waiting list. General Surgery patient attendances to SAU fell from an average of 1020 per month between March to October 2021 to 542 attendances November 2021 to present.

Conclusions

The introduction of a consultant-led ambulatory service has reduced the on-call burden by half. The dramatic reduction in SAU attendances is likely to be the result of developed ambulatory pathways, improved communication with primary care and Consultant Emergency General Surgeons, and autonomy of Junior Surgical Trainees to redirect ED referrals onto refined and supported ambulatory pathways. A Consultant-led primary care access line has reduced ED attendances and allowed for effective streaming of patients. These changes have improved the patient experience significantly, by directing them straight to specialty with same or next day consultant clinics, and reduced waiting times overall. There has been a significant reduction in complaints and consistent improvement in patient feedback.
EGS P24 Extended Thromboprophylaxis in the Prevention of Postoperative Venous Thromboembolism after Emergency Surgery
Authors: Clements Caterina , Bezzaa Sabrina , Patel Puja , Graham Gemma , Kersey James , Nehra Dhiren , Lewis Trystan , Jamal Karim
Published: December 2022

Background

Venous thromboembolism (VTE) after emergency laparotomy is a significant cause of morbidity and mortality.

Where extended thromboprophylaxis is used in the post-operative care of patients with colorectal malignancy or pelvic surgery, no such guideline exists for the patient undergoing emergency laparotomy.

Arguably emergency laparotomy has one of the highest associated death rates of all types of surgery, greater than that of major elective GI surgery and involves high risk patients.

The objective of this study is to ascertain the incidence of symptomatic VTE after emergency laparotomy within current thromboprophylaxis regimens at a district general hospital and consider the benefits of extended regimes in this patient cohort.

Methods

A database of all patients who underwent emergency laparotomy over a 12 month period from January 2019 to December 2019 was retrospectively analysed. The primary outcome was the incidence of symptomatic VTE within 90 days of emergency laparotomy. This was cross-referenced to known patient risk factors for thromboembolism.

Results

A total of 113 patients underwent emergency laparotomy during this period. Those who had multiple laparotomies and were duplicated or who died were excluded, leaving a total of 94 patients, 55 female and 39 male.

80 patients underwent a VTE prophylaxis regimen using perioperative and postoperative low-molecular-weight heparin (LMWH) based on their weight.

The average length of stay was 18 days. 20 patients had an inpatient stay greater than 28 days and, therefore, received extended prophylaxis during their admission. 21 patients were given prolonged anticoagulation on discharge to complete a total of 28 days, 14 of these had suspected cancer intraoperatively, 6 were previously already anticoagulated.

The postoperative VTE incidence was 6, 4 were diagnosed during admission and so received prolonged anticoagulation on discharge. 2 patients were not given prolonged VTE prophylaxis on discharge.

Conclusions

An extended VTE prophylaxis regimen using low-molecular-weight heparin is simple and effective and an accepted practice in the management of post operative colorectal cancer patients. A randomised control trial is likely needed to further explore the use of extended low molecular weight heparin in the postoperative care of emergency laparotomy patients.
EGS P26 Audit of outcomes of Hiatus hernia repairs done as an emergency procedure in a tertiary care center
Authors: Eadala Haripriya , Abdelhamid Amir , Mekhail Peter , Nanthakumaran Shayanthan
Published: December 2022

Background

Hiatus hernia is the abnormal protrusion of stomach and /or intra-abdominal contents into the chest via a widened space between the diaphragmatic crura. Patients with hiatus hernias can present with a wide spectrum of symptoms ranging from a mild dyspepsia to acute presentations such as obstruction and strangulation. The recurrence rate, morbidity and mortality in patients requiring emergency surgeries in such acute presentations has been reported to be significantly high compared to that of elective hernia repair. We aim to assess the outcomes of hiatus hernia repairs done as an emergency surgery in a tertiary care center.

Methods

A retrospective study of all emergency hiatus hernia repairs done over a span of 10 years was done. Demographic details, BMI, smoking status, past medical history, method of diagnosis and management, duration of inpatient stay and the follow up was collected. The primary outcome of the study was 30 day mortality rate. Secondary outcomes were further surgeries during the same admission and recurrence rate.

Results

A total of 25 patients were identified to undergo an emergency hiatus hernia repair. 1 patient was excluded due to transfer to a different health board. 62.5%(n=15) of the patient were females. Duration of stay as inpatient ranged between 3 and 138 days. Of note, there were no deaths during the stay or recorded mortality by 30 days in the cohort.

Conclusions

The mortality rate in our unit is low in comparision with reported studies in literature.