bluuebunny/crossref_metadata_2025 huggingface dataset:
O232: Enzymatic blood group conversion prevents complement activation in an ABO-incompatible model of human kidney transplantation
Authors: MacMillan Serena , Hosgood Sarah , Rahfeld Peter , Walker-Panse Léonie , Macdonald Spence S , Kizhakkedathu Jayachandran N , Withers Stephen G , Nicholson Michael
Published: March 2024

Introduction

Recently, enzymatic blood group conversion has been used to convert human kidneys from blood group A to universal blood group O using bacterial enzymes from Flavonifractor plautii. However, little is known about the functional consequences of antigen removal when a treated kidney is transplanted in an ABO-incompatible (ABOi) recipient. Here, we investigated classical complement activation during ABOi conditions in enzyme treated (ABOe) vs control human type A kidneys.

Method

Three biological pairs of type A human kidneys rejected for transplantation and offered for research were used in this study. One kidney per pair was treated with 1mg/L of FpGalNAc deacetylase and FpGalactosaminidase during 6hrs of hypothermic machine perfusion while the contralateral kidney was perfused without enzymes. Both kidneys were subsequently perfused for 4hrs in ABOi conditions using normothermic machine perfusion (10% AB serum; mouse anti-A IgM titre 1:128; type O red blood cells). Tissue-bound components of classical complement activation were assessed in pre- and post-perfusion biopsies.

Results

Following ABOi perfusion, control kidneys showed peritubular deposition of the classical complement component C1qA and further complement activation components C4d and C5b-9. The staining directly co-localised with regions of anti-A staining. In ABOe kidneys, no anti-A staining was observed, with no C1qA, C4d, or C5b-9 staining found in post-perfusion biopsies.

Conclusions

We have shown for the first time that ABOe kidneys do not activate the classical complement pathway in ABOi conditions. This work shows the potential of the enzymatic blood group conversion to evade hyperacute antibody-mediated rejection during renal transplantation.
O147: Use of the National Consultant Information Programme to evaluate surgical practice in England for rectal prolapse repair, identifying points of variation for improvement and the impact of the Covid-19 pandemic
Authors: King Hazel , Maxwell-Armstrong Charles , Booth Matthew , Williams Norman
Published: March 2024

Introduction

Using the National Consultant Information Programme (NCIP) tool to extract and analyse data surrounding rectal prolapse repair procedures, to identify key trends and variation. Analysing data across a 4-year period to evaluate how the Covid-19 pandemic impacted current surgical practice.

Methods

NCIP compiles hospital episode statistics data gathered by NHS analysts. Data is categorised by key metrics including length of stay (LOS), procedure approach, deprivation score and pseudonymised provider. Data is for elective procedures in patients 17+ and has been contextualised by recent available literature.

Results

Of the 6702 procedures, 65.8% (4413) were carried out in the first time period, 1st April 2018 to 31st March 2020. Abdominal prolapse repair increased from 37.0% of procedures in the first 2 years, to 42.4% in the second period (1st April 2020 to 31st March 2022). Perineal approach decreased from 45.6% of procedures to 41.1% in the second period. 87.7% of patients were female. Most procedures were open (77.7%). Average LOS was 2.5 days and was highest in laparoscopic assisted procedures (5.38), 2.33 in open procedures. From 141 providers, the top 15 did 100-218 procedures each across the 4 years. 24 providers performed 15 or less, while 5 performed only 1 repair. Mortality within 90 days was 0.81% in the first data period and increased to 1.1% in the second.

Conclusion

Data suggests an impact on procedure numbers due to Covid-19, but not on approach type. Significant observed variation between provider approach and procedure count invites further research into reasons behind this.
O239: Identification of novel radiosensitisers in colorectal cancer cells
Authors: Kler Aaron , Fok Matthew , Parsons Jason , Grundy Gabrielle , Vimalachandran Dale
Published: March 2024

Introduction

Locally advanced rectal cancer is typically treated with neoadjuvant chemoradiotherapy, where chemotherapy acts synergistically to radiosensitise cancer cells. Response to chemoradiotherapy is variable, with 8-20% of cases having a complete pathological response, but 20-30% demonstrate no response or disease progression. Novel radiosensitisers can potentially improve response, tolerability of radiotherapy and de-escalate treatments, including the need for major surgery. This study aims to perform a screen of available FDA-approved drugs to identify novel radiosensitisers in rectal cancer.

Methods

A drug screen of forty FDA-approved drugs was performed. HCT-116 cells were cultured and treated as a monolayer with 0.3μM and 1.0μM of a specific drug for 16 hours. Clonogenic assays were performed in 24 well plates after photon irradiation at 0 and 1 Gy. Relative colony formation (survival fraction) was employed to measure drug efficacy and radiosensitisation. Following the screen, two drugs were selected for dose optimisation and further mechanistic evaluation with DNA repair kinetics and DNA damage using immunofluorescence of γH2Ax foci.

Results

Abexinostat and Fomepizole were selected from the screen for dose optimisation based on their radiosensitising capabilities. Dose optimisations determined both drugs had an optimal concentration of 0.5 and 1.0μM and required an optimum of 6 hours of treatment, and showed significant radiosensitisation. Prolonged DNA repair kinetics and significantly more γH2Ax foci in cells treated with Abexinostat and Fomepizole indicated persisting DNA damage.

Conclusion

Abexinostat and Fomepizole show promise as radiosensitizers. Further experimentation is ongoing to determine the mechanism of action for these drugs and their translational potential.
O102: Is there a gender disparity in the understanding and perceptions of orthopaedic surgery? Outcomes of The South West Orthopaedic Conference 2023
Authors: El-Hassan Mohammed , Drake Will , Jones Conor
Published: March 2024

Aim

This study aimed to evaluate the differences in understanding and perceptions of orthopaedic surgery between male and female delegates in a national student-led conference.

Method

This was a conference organised by students with the support of consultants from The Royal Devon and Exeter Hospital. The pre- and post-conference questionnaire had three sections comprising of understanding, motivations and barriers to pursing orthopaedic surgery. The results of this study analysed the pre-conference data differences between male and female delegates. Mann-Whitney test was used to determine differences in pre-conference responses according to gender.

Results

62 delegates completed the questionnaire, of which 63% were male. There were no differences between genders on understanding of orthopaedics in the pre-conference questionnaire (p>0.05). Salary was more of a motivating factor in male delegates compared to female delegates (p<0.05). Lack of role models, number of years spent training and work-life balance were perceived as a barrier in more female compared to male delegates (p<0.05). There was no significant difference in lack of exposure during undergraduate training or negative experiences in orthopaedic placements in both genders.

Conclusion

The conference data highlighted that lack of role models, work-life balance and the length of orthopaedic training were more of a perceived barrier in females compared to males. We therefore encourage organisations such as Women In Surgery (WinS) and orthopaedic surgeons to encourage more female representatives in orthopaedics by providing provide support for student-led initiatives, to encourage the recruitment of women in orthopaedic surgery.
O36: Patient acceptability and adherence to the COMPASS trial drug recommendations following symptomatic carotid endarterectomy (CEA)
Authors: Eveson Tom , Cruddas Lucinda , Penge Justin , Bakhai Ameet , Baker Daryll
Published: March 2024

Introduction

The COMPASS trial demonstrated that in patients with atherosclerotic diseases, low-dose rivaroxaban and aspirin provides greater protection against subsequent cardiovascular events than antiplatelet monotherapy (MAPT) alone. Medication adherence is necessary to maximise this benefit and is dependent on patient views. We have assessed this in patients following CEA.

Methods

Following CEA, the views of 63 patients on the COMPASS drug regime were compared with 54 on MAPT. Views on medications was assessed using the Beliefs about Medicine Questionnaire (BMQ) and drug adherence using the Sidorkiewicz scoring system. Side effects and the incidence of new cardiovascular events were also assessed.

Results

Both groups had similar age (mean 70.6+/-8.7), gender (M:F 2:1), and deprivation indices. Preoperative co-morbidities were similar between groups, as were intervention indications (TIA or stroke). There was no difference (p<0.05) between the COMPASS drug regime and MAPT in BMQ for “Necessity” (19.6 v 19.1), “Concerns” (11.8v 12.0) or the “Necessity–Concerns differential”(+7.8v+7.1). Drug adherence was similar with the median showing a “High drug adherence”. The incidence of bleeding and drug reaction complications was similar. Numbers of new stroke, ischaemic cardiac events, and peripheral vascular disease diagnoses was similar, as was the combined overall major adverse cardiovascular events (MACE).

Conclusions

Following CEA, patients’ views on medications and their drug adherence are similar in those on the COMPASS drug regime as on MAPT. We have not identified any patient-related barriers to the use of the COMPASS drug regimen to further reduce cardiovascular events.
O68: Long term stroke prevention drug therapy following Carotid endarterectomy (CEA) is good, but could be better
Authors: Hirschowitz David , Chen Xiaoyu , RAHIM Lily , Baker Daryll
Published: March 2024

Introduction

CEA reduces the risk of future stroke. The benefit is maximised with live-long drug therapy to reduce major adverse cardiovascular events (MACE), including stroke. Studies suggest around half discontinue these drugs within 12 months. We compared the drugs prescribed at CEA with those prescribed several years later.

Methods

Of 347 patients who underwent CEA between 2010-2019, at late follow-up (9+/-3.1y), 187 (54%) patients were alive. The prescription of generic MACE-reducing drugs (anti-thromboembolic, lipid-lowering, b-blockers and ACE-Inhibitors) and incidence of cardiovascular risk factors (hypertension, diabetes, ischaemic cardiac disease, stroke) at CEA were compared with that at late follow-up.

Results

At late follow-up, fewer were taking antiplatelet drugs (170v143 p<0.01), but more were formally anticoagulated (4v37 p<0.01). Overall there was no change in anti-thromboembolic prescription rates. Lipid-regulating drugs were equally highly prescribed at CEA and follow-up (169v173), Both B-blocker and ACE-Inhibitor prescriptions rates were low, but had increased by follow-up (46v69 p<0.01; 38v88 p<0.01). More patients were treated for hypertension at follow-up (67v166 p<0.01), but numbers with managed diabetes had not changed at late follow-up. 47 (25%) of patients had a history of ischaemic heart disease at CEA and 24 (14%) had developed new symptoms. There were 22 (12%) new strokes at late follow-up.

Discussion

Despite a higher than expected prescription rate of MACE-reducing drugs years after CEA, which is tailored to the patient’s changing needs, continued improvement is needed to optimise cardiovascular protection fully.
O224: Patient Services Not Fit for Purpose: Analysis of Skin Cancer Pathway
Authors: Lau Jessica , Marla Ananya , Borra Poojit , Parthiban Sunil , Butler Peter , Ponniah Allan
Published: March 2024

Background

NHS public satisfaction fell to 29% in 2022; a record low in NatCen’s British Social Attitudes report since its debut in 1983. Exacerbated by COVID-19, services have redesigned to having an almost 3-fold increase in percentage of telehealth appointments. Now >40% of initial skin cancer appointments in our service are delivered remotely, an approach prioritising efficiency over patient-centred care. This study attempts to gain a comprehensive understanding of patient perceptions and attitudes in our skin cancer pathway.

Method

A snapshot survey of 103 consecutive patients, aged 22-96, 58% female, was conducted over one year at the Royal Free Hospital's skin cancer service. Data was analysed using thematic analysis, allowing for identification of recurring themes and patterns, following the American Association for Public Opinion Research’s guidelines for population analysis. Statistical analysis of frequency data was also applied.

Results

Key findings include a clear preference towards face-to-face as opposed to tele-dermatology in 62% of patients. Tele-dermatology’s primary drawback is only allowing for the assessment of one lesion in a clinic appointment, leaving 54% of patients with multiple unassessed lesions. Patients expressed satisfaction (72%) with waiting times for their initial appointment, however, 68% of patients were dissatisfied with the waiting time for their biopsy results.

Conclusions

The present configuration of services is not fit for patient needs. This study identifies key themes addressing appointment scheduling, telehealth limitations and communication preferences, offering guidance to healthcare providers to improve the quality of care for skin cancer patients, enhancing patient satisfaction and overall healthcare quality.
O244: Patients’ priorities in Vulval lichen sclerosus – results of a patient and public involvement for a study investigating autologous lipotransfer and platelet-rich plasma in Vulval lichen sclerosus
Authors: Jasionowska Sara , Almadori Aurora , Langridge Benjamin , Hansen Esther , Butler Peter
Published: March 2024

Background

Vulval lichen sclerosus (VLS) is a high-burden, under-researched chronic skin disease. It is characterised by itching, pain, sexual dysfunction and poor quality of life. Up to 70% of patients develop fibrosis and vulval architectural changes. The only evidence-based treatment includes topical steroids. New potential surgical treatments include autologous fat transfer (AFG) and platelet-rich plasma (PRP) injections but high-level evidence supporting these treatments is sparse.

Aims

To identify patients’ research priorities and evaluate the acceptability of AFG and PRP as treatments for VLS and design a trial co-produced by patients.

Methods

One-to-one interviews, focus groups and online questionnaires were used to investigate patients’ research priorities, acceptability of treatments, preferred outcome assessment tools, views on a sham procedure and trial design.

Results

A focus group (n=18) and an online patient survey (n=809) identified the top research priorities: changes to vulval anatomy, emotional impact on intimate relationships, inability to have penetrative intercourse and pain during intercourse. Patients reported poor quality of life and said that addressing these would be life-changing. Ninety-nine percent of patients agreed that this trial should be performed and 73% were willing to take part if a sham procedure was used. A patient advisory group (n=5) has been created to co-produce the trial.

Conclusion

VLS is a complex disease with no core outcome set. Patient co-production is a keystone to a successful trial design and ensures that research is aligned with patients’ priorities. This research defines the key priorities of research into current surgical interventions for VLS.
O152: Prognostic value of receptor positivity loss following neoadjuvant chemotherapy in breast cancer patients: a systematic review and meta-analysis
Authors: Dowling Gavin , Alrawashdeh Maen , Daly Gordon , Hembrecht Sandra , Hill Arnold
Published: March 2024

Introduction

Receptor status of breast cancer (BC) has been reported to change after neoadjuvant treatment leading to discordance between diagnostic biopsy and surgical specimens. This meta-analysis aims to investigate the prognostic significance of a loss of human epidermal growth factor receptor 2 (HER2) and hormone receptor positivity in residual disease after neoadjuvant therapy.

Methods

A systematic search of electronic databases was conducted to identify studies that investigated the impact loss of receptor status had on prognosis. Studies reporting disease free survival (DFS) and/or overall survival (OS) hazard ratios (HRs) for loss of HER2 or hormone receptor positivity following neoadjuvant treatment for BC were included. A meta-analysis was undertaken for relevant studies. Pooled hazard ratios were calculated using 95% confidence intervals (CIs).

Results

Eight studies with a total of 2673 patients were included in the meta-analysis. Patients who lost HER2 positivity had significantly worse OS (pooled HR 1.80, 95% CI 1.01-3.22, p=0.05) and DFS (pooled HR 2.03, 95% CI 1.47-2.82, p<0.001), compared to those who maintained positivity. Similarly, patients with a loss of hormone receptor positivity had significantly worse OS (pooled HR 2.49, 95% CI 1.65-3.77, p<0.001) and DFS (pooled HR 3.71, 95% CI 1.79-7.69, p<0.001) than those who remained hormone receptor positive after neoadjuvant therapy.

Conclusion

This meta-analysis found that a loss of either HER2 or hormone receptor positivity following neoadjuvant therapy negatively impacted survival outcomes. These findings suggest that retesting of receptor status may offer prognostic information, in addition to potentially altering adjuvant treatment regimens.
O22: Postoperative Telemedicine is feasible and sustainable; a prospective life-cycle assessment approach to carbon footprint analysis
Authors: Lathan Ross , Walshaw Josephine , Hitchman Louise , Ravindhran Bharadhwaj , Carradice Daniel , Smith George , Chetter Ian , Lockwood Sonia , Yiasemido Marina
Published: March 2024

Introduction

The NHS must provide a net zero service by 2045. Innovative strategies are required to quantify, evaluate and implement environmentally friendly interventions into practice. The study evaluates the feasibility and sustainability of remote post-operative follow-up using novel methodology.

Methods

Patients were reviewed remotely and face-to-face at 30 days post-operatively. A prospective life-cycle assessment(LCA) approach to carbon footprint analysis was used to calculate carbon emissions kgCO2e. Patient postcodes were applied to conversion factors to calculate travel emissions. Median(IQR) kgCO2e saved were presented. Carbon offsetting values are based on kgCO2e sequestered by a standardised UK variety tree.

Results

31 participants(M:F 2.4, 66.7±11.7 years) were included. The median return distance for patient travel was 42.5km(7.2-58.7). Median reduction using remote follow-up was 41.2 kgCO2e(24.5-80.3) per patient(P<0.001). Using remote follow-up is equivalent to planting 1 tree for every 6.9 patients reviewed. Every readmission with SSI results in an additional 1219.93 kgCO2e.

Discussion

This model shows that the prospective LCA approach is achievable. Implementation of an asynchronous follow-up model is effective in substantially reducing the carbon footprint of a tertiary vascular surgical centre. Further work is needed to corroborate these findings on a larger scale and incorporate kgCO2e into cost analysis of SSI monitoring strategies.
O2: The development of anti-bullying, discrimination, and harassment guidance: A survey among the association of surgeons in training (ASiT) council members
Authors: El Boghdady Michael
Published: March 2024

Introduction

Surgical trainees have a reasonable expectation to feel safe and valued in their workplace. Previous reports proved that poor behaviour and misconduct existed in national health system. We aimed to conduct a survey among ASiT council members to identify the need of guidance to report bullying, discrimination, and harassment for trainees who experienced any type of poor behaviour at workplace.

Methods

Data among executive and council members was collected. Questions were related to trainee demographics, level of training, specialities, experienced, witnessed, or reported poor behaviours including bullying, discrimination and harassment. We asked if participants lacked direction when experienced poor behaviours, if support strategies were needed such as a standardised guidance for reports.

Results

A total of 58 survey responses were received, 55.17% of participants experienced bullying, 77.58% witnessed it and 67.25% did not report. While 37.93% experienced discrimination, 62.07% witnessed it and 68.97% did not report. A total of 24.14% experienced sexual harassment, was witnessed in 29.69%, 72.41% did not report. Over eighty percent mentioned they need more guidance to support trainees. Almost all participants (98%) agreed that surgical trainees should be made aware of routes for reporting, and 88% agreed that ASiT should develop the guidance to support trainees against poor behaviours.

Conclusion

Most of the trainees who experienced or witnessed poor behaviours did not report the incidents. A new standardised anti-bullying, anti-discrimination, and anti-harassment guidance was developed based on our study results. We envisage that its use may play a role in eliminating misconducts in surgical training.
O262: Evaluating the role and efficacy of virtual reality and simulation in teaching acute and trauma scenarios – a systematic review
Authors: Kavallieros Konstantinos , Tran Mi-Tra , Ahmad Manal , Ahmad Basma , Shalhoub Joseph , Davies Alun
Published: March 2024

Introduction

Simulation allows trainees to practice skills safely and is the current gold standard method of teaching. More recently, novel methods such as virtual reality (VR) and augmented reality are being explored as possible methods of teaching.

Aims

To evaluate the current evidence pertaining to simulation and VR as methods of teaching in teaching acute and trauma management.

Methods

A systematic review was conducted using the PRISMA guidelines. Medline and Embase (via Ovid interface) were used to search for articles up to March 2023. The following MeSH terms were used: ‘(virtual reality OR VR) AND (acute surgical OR surgery OR trauma OR trauma management) AND (medical education OR education OR surgical training OR training) AND simulation’.

Results

A total of 3815 articles were identified. 2648 were screened upon de-duplication. 40 articles underwent full-text review; 14 were extracted. Prospective cohort studies were the most common, 43.8%. Experimental studies included a total of 436 participants, with a median sample size of 23 (IQR:14–32). 6 studies compared VR to simulation methods. Half of these articles indicated favourable conclusions towards VR training compared to standard training. A further 8 studies evaluated feasibility of VR training only – all had favourable outcomes for VR.

Conclusion

This review identified a range of evidence indicating that VR can be useful for training of acute surgical scenarios. VR was generally a well-received training modality although unlikely to replace simulation entirely. More robust statistical analysis in further studies is required, with investigation into the longer-term impact of VR training.
O69: Exploring clinical study outcomes for pelvic venous disorders: An in-depth 10-year review of the literature
Authors: Kavallieros Konstantinos , Pope Tasneem , Tan Matthew , Sekhon Harmeena , Gianesini Sergio , Lazarashvili Zaza , Jaworucka-Kaczorowska Aleksandra , Narayanan Sriram , Gwozdz Adam , Davies Alun
Published: March 2024

Objective

There is increasing recognition that health systems need to improve the value of patient care by measuring outcomes. Pelvic Venous disorders (PeVD) can have a significant impact on the quality of life of women affected and despite growing recognition, remain underdiagnosed. Developing a core outcome set (COS) for benchmarking care delivery enhances the standardisation of care. We aimed to generate a list of outcomes reported in previous PeVD treatment studies to lay the foundation for developing a COS for PeVD.

Methods

This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping reviews (PRISMA-ScR). Closely related outcomes were classified into domains, and domains into three core areas: disease-specific, treatment-related, quality of life (QOL)-related outcomes.

Results

Of the 951 records identified, 43 publications were included. From these studies, 96 different outcomes were identified. Closely related outcomes were organised into 37 outcome domains, which were then categorised into 3 core outcome areas; 16 (43%) were disease-specific, 15 (41%) treatment-related, and 6 (16%) were QOL related. Of the 43 studies included, disease-specific outcomes were identified in 41 (95%) studies, treatment-related outcomes in 41 (95%) studies, and quality of life outcomes in only 6 (14%) studies.

Conclusions

There was significant heterogeneity in outcomes reported in PeVD studies. Most PeVD treatment studies evaluated disease-specific and treatment-related outcomes features of PeVD, but few reported outcomes that measured the impact of quality of life. These findings will inform the next steps in developing a core outcome set for PeVD.
O70: A Novel Screening Tool for Pelvic Venous disorders
Authors: Kavallieros Konstantinos , Pope Tasneem , Tan Matthew , Narayanan Sriram , Gwozdz Adam , Davies Alun
Published: March 2024

Objective

Pelvic venous disease (PeVD) remains a common yet under-diagnosed condition, and there remains no standardised diagnostic work-up. A self-assessment questionnaire was developed to aid the identification of women with PeVD. The study aimed to assess the performance of the questionnaire score in identifying patients with PeVD.

Methods

Retrospective data analysis from consecutive referrals to a vascular surgery clinic in Singapore between 2018-2022. Before diagnostic evaluation, patients completed a novel, 6-item questionnaire, resulting in a Basic Score. From 2022, patients completed an additional 4-item questionnaire developed as an adjunct, resulting in a Specific Score - adding Basic and Specific Scores yields the Combined Score. Duplex US was used as the reference standard.

Results

A total of 94 women were assessed. Of these, 73 (77.8%) met DUS criteria for PeVD. All completed the Basic questionnaire, which demonstrated high discriminatory ability (area under the receiver-operating curve (AUC) of 0.878 [95% CI:0.779-0.977]). A Basic Score ≥3 had high sensitivity and moderately high specificity of 93.2% [95% CI: 84.7 -97.7] and 81.0% [95% CI:58.1 – 94.6], respectively. 36.2% (34/94) of patients answered both questionnaires. There was insufficient evidence that the Specific questionnaire improved performance (AUC 0.979 [95% CI: 0.937 – 1.00] vs 0.966 [95% CI:0.903 -1.00], for Basic Score vs Combined Score).

Conclusions

Our findings suggest that the Basic questionnaire may be useful in the diagnostic workup of PeVD, potentially increasing referral to vascular specialists for appropriate management. However, diagnostic accuracy may be over-estimated due to high disease prevalence in the cohort, prohibiting generalisation of results.
O159: Designed to Respect and Repair the Abdominal Aorta: A 9-year International Experience with the Fenestrated Anaconda Endograft
Authors: Jubouri Matti , Surkhi Abdelaziz , Tan Sven , Bailey Damian , Williams Ian , Bashir Mohamad
Published: March 2024

Background

Endovascular aortic repair (EVAR) has become the mainstay treatment for abdominal aortic aneurysms and is associated with optimal clinical outcomes. However, there remains a risk of complications requiring reintervention. Several EVAR devices exist commercially, yet, the Terumo Aortic Fenestrated Anaconda™ (FA) has demonstrated outstanding results.

Methods

The current study represents a 9-year cross-sectional international analysis of custom-made FA. Data was collected prospectively in 27 countries and stored in a registry. This was later retrieved and analysed retrospectively.

Results

A total of 5058 patients received the FA endograft. This was indicated either due to complex anatomy for competitor devices (n = 3891, 76.9%) or based on surgeon preference (n = 1167, 23.1%). Overall, the FA was utilised to rescue 3466 (68.5%) failed previous EVARs using competitor devices. The predominant device category and proximal ring stent configuration were bifurcate (83.6%) and standard (64.5%). Most were delivered within 6-8 weeks (55.4%) of diagnosis and 95% came with a prototype. As for clinical outcomes, both survival and TVP were 100% during the first 6 postoperative years but dropped to 77.1% and 81% thereafter. A sac regression of 0-30% was observed in 4772 (94.3%) over the first 4 years, whilst all patients had 20-45% sac regression afterwards. No cases of endograft migration or reintervention were recorded. All clinical outcomes were further stratified by indication group.

Conclusion

The custom-made FA endograft features a highly unique and innovative design which enables it to treat highly complex aortic anatomy while achieving favourable results.
O130: Apoptosis Post Microwave Ablation of the Liver: Does it Change with Power?
Authors: Alzaraa Ahmed , Zayyan Kassim , West Kevin , Morgan Bruno
Published: March 2024

Apoptosis helps eradicate the remained cancer cells after microwave ablation. The extent of its expression is yet to be defined.

Aims

To investigate whether the ablation power made any difference to the expression of apoptosis in the ablated and normal areas.

Methods

Ablations with 50W, 70W, and 90W powers were created in three ex vivo perfused porcine livers. Biopsies from the lesions were assessed with Hematoxylin-Eosin and immunohistochemistry (Caspase 3 and M30) looking for apoptosis in each zone (central necrotic zone [CNZ], transitional zone [TZ], and normal surrounding zone [NZ]). Statistical analysis was performed using ANOVA and t-test.

Results

None of the CNZ showed expression of Caspase-3. In the TZ, there was significant difference between 50W and 90W (P = 0.009), but not between 50W and 70W (P = 0.8), or between 70W and 90W (P = 0.4). In the NZ, a highly significant difference was noted between 50W and 90W (P = 0.003), a significant difference between 50W and 70W (P = 0.01), but not between 70W and 90W (P = 0.06). For M30, no expression of M30 was noted in all necrotic zones. A significant difference was noted between 50W and 90W (P = 0.02). There were no significant differences between 50W and 70W (P = 0.4) or between 70W and 90W (P = 0.07).

Conclusion

Increasing power enhances apoptosis in the ablated areas. This response can be an adjunct for eradicating cancer cells that might escape the heat in the ablated zones.
O80: Intensive pre-operative information course (IPIC) and pre-operative weight loss results in long-term sustained weight loss following bariatric surgery: 11year results from a Tertiary Referral Centre
Authors: Lucocq James , Andrew de Beaux , Tulloh Bruce , Lamb Peter , Robertson Andrew
Published: March 2024

Introduction

Outcomes of long-term (5-10 year) weight loss have not been investigated thoroughly and the role of pre-operative weight loss on long-term weight loss, among other factors, are unknown. Our regional bariatric service introduced a 12-week intensive pre-operative information course (IPIC) to optimise pre-operative weight loss and provide education prior to bariatric surgery. The present study determines the effect of pre-operative weight loss and an intense pre-operative information course (IPIC), on long-term weight outcomes and sustained weight loss post-bariatric surgery.

Methods

Data were collected prospectively from a bariatric center (2008-2022). Excess weight loss (EWL) ≥50% and ≥70% were considered outcome measures. Survival analysis and logistic regression identified variables associated with overall and sustained EWL≥50% and ≥70%.

Results

339 patients (median age, 49 years; median follow-up, 7 years [0.5-11years]; median EWL%, 49.6%.) were evaluated, including 158 gastric sleeve and 161 gastric bypass. During follow-up 273 patients (80.5%) and 196 patients (53.1%) achieved EWL≥50% and ≥70%, respectively. In multivariate survival analyses, pre-operative weight loss through IPIC, both <10.5% and >10.5%EWL, were positively associated with EWL≥50% (HR2.23,p<0.001) and EWL≥70% (HR 3.24,p<0.001), respectively. After a median of 6.5years after achieving EWL50% or EWL70%, 56.8% (154/271) had sustained EWL50% and 50.6% (85/168) sustained EWL70%. Higher pre-operative weight loss through IPIC increased the likelihood of sustained EWL≥50% (OR,2.36;p=0.013) and EWL≥70% (OR,2.03;p=0.011) at the end of follow up.

Conclusions

IPIC and higher pre-operative weight loss improve weight loss post-bariatric surgery and reduce the likelihood of weight regain during long-term follow-up.
O119: Investigating the Secretome of Adipose Derived Stem Cells on Extracellular Matrix Remodelling in Radiation-Induced Fibrosis
Authors: Wai Jasmine May Yen , Cui Xiang Mei , Langridge Benjamin James , Frommer Marvin , Butler Peter E M
Published: March 2024

Background

Radiation-induced fibrosis (RIF) is a debilitating complication following radiotherapy, characterised by fibroblast proliferation and excessive extracellular matrix (ECM) deposition, leading to functional and aesthetic impairments. Although autologous fat grafting (AFG) has shown promise in reversing RIF, the mechanisms, largely attributed to adipose-derived stem cells (ADSCs), remain elusive. This study aimed to investigate ADSCs’ and their secretome on ECM remodelling in RIF management.

Methods

The anti-fibrotic potential of the ADSC secretome on HDFs subjected to ionising radiation was assessed via a series of in vitro experiments. Control HDFs were compared with irradiated HDFs to assess any phenotypical changes. Irradiated HDFs were treated with ADSC pre-conditioned media (CM) or ADSC co-culture (CC). Gene expression (COL1A1, TGF-β, CCN-2, MMP-1, MMP-3, TIMP-1, ACTA2, TNC) was assessed via real-time quantitative PCR (RT-qPCR). ProCollagen1a1 and CCN2 protein concentrations were assessed by ELISA.

Results

Irradiated HDFs demonstrated changes in fibrotic gene expression. ADSC-CM treatment significantly reduced COL1A1 expression, although protein levels remained unchanged. TGF-β1, CCN2, MMP-3, TIMP-1 and ACTA-2 exhibited reduced expression post-ADSC-CM treatment whereas TNC expression was found to be significantly increased. Co-culture with ADSCs led to a general, but not statistically significant, decrease in pro-fibrotic gene expression. Notably, CCN-2 protein expression significantly increased.

Conclusion

This study demonstrates that ionising radiation results in a pathological pro-fibrotic phenotype in HDFs. The ADSC secretome potentially mitigates this, reducing pro-fibrotic gene expression. Unexpectedly, co-culture experiments highlighted a complex interaction with upregulation of fibrosis-associated genes. Further research is needed to clarify these interactions to improve therapeutic interventions for RIF.
O26: Sarcopenia versus clinical frailty scale in predicting the risk of postoperative mortality after emergency laparotomy: A retrospective cohort study
Authors: Linganathan Saranya , Saji Alwin Puthiyakunnel , Hughes Ioan , Mitra Kalyan , Hajibandeh Shahin , Hajibandeh Shahab
Published: March 2024

Objectives

To compare predictive significance of sarcopenia and clinical frailty scale (CFS) in terms of postoperative mortality in patients undergoing emergency laparotomy.

Methods

In compliance with STROCSS statement standards a retrospective cohort study with prospective data collection approach was conducted. The study period was between January 2017 and January 2022. All adult patients with non-traumatic acute abdominal pathology who underwent emergency laparotomy in our centre were included. The primary outcome was 30-day mortality and secondary outcomes were in-hospital mortality and 90-day mortality. The predictive value of sarcopenia and CFS were compared using the Receiver Operating Characteristic (ROC) curve analysis and multivariable binary logistic regression analysis.

Results

A total of 1043 eligible patients were included. The risk of 30-day mortality, in-hospital mortality, and 90-day mortality were 8%, 10%, and 11%, respectively. ROC curve analysis suggested that sarcopenia is a significantly stronger predictor of 30-day mortality (AUC: 0.87 vs 0.70, P<0.0001), in-hospital mortality (AUC: 0.79 vs 0.67, P=0.0011), and 90-day mortality (AUC: 0.79 vs 0.67, P=0.0009) compared with CFS. Moreover, multivariable binary logistic regression analysis identified sarcopenia as an independent predictor of mortality [Coefficient: 4.333, OR: 76.16 (95% CI 37.06-156.52), P<0.0001] but not the CFS [Coefficient: 0.096, OR: 1.10 (95% CI 0.88–1.38), P=0.4047].

Conclusions

Sarcopenia is a stronger predictor of postoperative mortality compared with CFS in patients undergoing emergency laparotomy. It cancels out the predictive value of clinical frailty scale in multivariable analyses; hence among the two variables, sarcopenia deserves to be included in preoperative predictive tools.
O243: The effect of midcarpal fusions on dart thrower’s motion: a cadaveric study
Authors: Thompson Alexandra , Kennedy James , Rust Philippa
Published: March 2024

Introduction

Midcarpal osteoarthritis can be managed with several types of partial wrist fusion. Limited information is available regarding their effects on functional movement. Many daily activities require a coupled wrist movement, from radial extension to ulnar flexion, termed dart thrower’s motion (DTM). This study aimed to compare the effect of four different midcarpal fusions on DTM.

Methods

Twelve fresh-frozen cadaveric specimens were dissected. Sequential loading of tendons into radial extension and ulnar flexion enabled full DTM to be measured using goniometry. Specimens were tested at baseline and following each fusion, performed sequentially using Kirschner wires: (1) scaphocapitate fusion, (2) lunocapitate fusion with scaphoid excision, (3) four-corner fusion with scaphoid excision and (4) three-corner fusion with scaphoid and triquetral excision. A one-way ANOVA and Tukey test established the significance of differences in range of motion.

Results

Each procedure significantly decreased DTM compared with intact wrists. Scaphocapitate fusion resulted in the smallest mean reduction in movement from 78°–70° (p=0.0014). Four-corner fusion produced the greatest reduction in DTM from 78°–63° (p<0.0001). There was a significant difference in DTM between four-corner and scaphocapitate fusions (p=0.0338). There was no significant difference in the range of postoperative DTM between lunocapitate, three-corner, or four-corner fusions.

Conclusion

DTM was minimally affected by scaphocapitate fusion and maximally affected by four-corner fusion, with a significant difference seen between these two operations. However, as a 44°–87° range of DTM was maintained for four-corner fusions, this is felt to be adequate for function. These results could aid preoperative decision-making.
O176: Complement inhibition enhances hepatocyte viability in a cell model of transplant ischaemia reperfusion injury
Authors: Hand Rebecca , Malik Abdullah , Hulme Callum , Mahendran Balaji , Palmer Jeremy , Thompson Emily , Ali Simi , Sheerin Neil , Bates Lucy , Wilson Colin
Published: March 2024

Background

Liver transplantation is limited by the number of optimal organs for transplantation. Ischaemia reperfusion injury (IRI) plays a key role in the utilisation of organs for transplantation - many organs are still not used due to concerns over viability. We evaluated the C5 inhibitor Eculizumab (EZB) in a cell model of IRI.

Methods

HepG2 cells, an immortalised hepatocyte cell-line, were utilised to model IRI. Cells were incubated in an anoxic chamber to model 'ischaemia' and then 'reperfused' in a normoxic incubator for 4 and 1 hours, respectively. The incubation media was supplemented with perfusate from donation after circulatory death (DCD) livers that had undergone standard normothermic machine perfusion (n=2) and EZB treated perfusate (n=2).

Results

The IRI model reduced cell viability and proliferation (p≤0.05). However, the model created no significant changes in the production of biomarkers VEGF, IL-10, IL-8, GDF-15 and ROS (p>0.05). Notably, EZB therapy significantly increased anti-inflammatory IL-10 production (p≤0.0001) and expression (p≤0.001), whilst enhancing cell viability and proliferation (p≤0.0001).

Conclusion

The complement system may play an important role within IRI and complement inhibition is a promising treatment for DCD livers, as demonstrated by treatment of cells with EZB therapy. Further work is required to optimise the models and treatment strategy before clinical testing.
O163: CABG versus PCI in Heart Failure with Reduced Ejection Fraction Patients: A Systematic Review & Meta-analysis Stratified by Left Ventricular Ejection Fraction
Authors: Jubouri Matti , Surkhi Abdelaziz , Al-Tawil Mohammed , Mohammed Idhrees , Williams Ian , Bailey Damian , Bashir Mohamad , Awad Wael
Published: March 2024

Background

Comparing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in patients with heart failure with reduced ejection fraction (HFrEF) remains controversial within the literature. The current meta-analysis aimed to compare CABG and PCI in HFrEF patients regarding mortality and long-term survival, repeat revascularization, new postoperative myocardial infarction (MI) and stroke, stratified by the degree of LVEF reduction.

Methods

In a systematic review, a comprehensive literature search was conducted on multiple electronic databases using strict search terms. Twenty studies met the set inclusion/exclusion criteria. Meta-analysis of extracted data was conducted using the R-studio and STATA software. Furthermore, the aforementioned study endpoints were stratified by the degree of left ventricular ejection fraction (LVEF) reduction into severe (<35%), moderate (<40%) and mild (<50%).

Results

Data from 25,031 HFrEF patients was analysed, out of which 12,957 (52%) underwent CABG and 12,074 (48%) received PCI. Long-term survival was significantly higher in the severe (<35%) and mildly (<50%) reduced LVEF groups, with no significant different found in the moderately (<40%) reduced LVEF cohort. However, all 3 groups significantly favoured CABG in terms of need for revascularization, but no difference in stroke incidence was found. As for postoperative MI, this followed the same trend as survival. No evidence of significant heterogeneity or publication bias was found.

Conclusion

CABG yields more favourable results than PCI in HFrEF patients. Further stratifying the clinical outcomes measured by the degree of LVEF reduction sheds light on the importance of risk stratification of patients to optimise results.
O252: Studying the neuronal regenerative response to in-vitro laser axotomy
Authors: Wong Evelyn , Savvides Georgia , McSweeney Jared , Mortimer Alice , Das Raman , Reid Adam
Published: March 2024

Aims

Outcomes of peripheral nerve injury (PNI) remain suboptimal, and the intrinsic mechanisms directing regeneration of injured peripheral neurons are not completely understood. To study the cellular response to injury, it is critical to deploy a model that facilitates a precise and controlled transection. We aim to recreate clinical outcomes at a micrometer level and analyse the impact of injury parameters, such as the proximity of injury to the cell body, on neuronal survival and regeneration.

Methods

We cultured adult rat dorsal root ganglion (DRG) neurons and transected individual neurites with a high-precision laser at 25um and 125um from the cell body. We monitored for 24 hours using time-lapse microscopy and analysed cell survival and neurite regeneration, comparing between two distance groups.

Results

Following laser transection at 25um from the cell body, 56% (n=25) of neurons survived for 24 hours and 33.3% (n=12) regenerated. When laser-transected at 125um, 75% (n=40) of neurons survived and 73.1% (n=26) regenerated. The mean regenerative distance was 19.9um (n=4) when injured at 25um and 173.9um (n=19) at 125um.

Discussion

Our laser axotomy method facilitated efficient and precise transection of individual neurites. Distal injuries generated significantly higher survival rates and regenerative length and rates compared to proximal injuries. These findings mimic clinical outcomes where distal injuries have greater recovery than proximal injuries, thereby demonstrating the efficacy of this model for investigating cellular mechanisms directing peripheral neuron regeneration. We envisage that this model will facilitate future studies aiming to accelerate peripheral neuron regeneration in a clinical context.
O72: Machine perfusion in deceased-donor kidney transplantation: Cochrane review and meta-analysis
Authors: Tingle Samuel , Thompson Emily , Figueiredo Rodrigo , Moir John , Goodfellow Michael , Talbot David , Wilson Colin
Published: March 2024

Background

Several novel machine perfusion technologies have been developed which aim to improve kidney transplant outcomes compared with ice-box static cold storage (SCS). These machine perfusion technologies can be applied “continuous” from donor centre, or only at the recipient centre (“end-ischaemic”). We aimed to compare machine perfusion technologies with each other and with SCS.

Methods

We searched the Cochrane Kidney and Transplant Register of Studies to 20 June 2023. Two independent authors screened articles and extracted data. Pairwise random-effects meta-analysis was performed, with additional indirect comparisons performed.

Main results

22 studies (4007 participants) were included. “Continuous” non-oxygenated hypothermic machine perfusion (HMP) versus SCS improves graft-survival (follow-up=1-10 years, HR=0.55, 95% confidence interval=0.40-0.77, P=0.0005, GRADE: high-certainty evidence), reduces delayed graft function (RR 0.78, 0.64-0.96, P=0.02; high-certainty evidence) and is cost-saving. Beneficial effects persist when cold ischaemic times were short, but were only seen when HMP was “continuous”; End-ischaemic oxygenated HMP (median 4.6hours) does not improve outcomes. Addition of oxygen to continuous HMP further improves graft-survival in DCD donors. End-ischaemic normothermic machine perfusion (NMP) does not improve outcomes versus SCS; indirect comparison revealed that continuous non-oxygenated HMP was associated with improved graft survival compared with end-ischaemic NMP (HR=0.31, 0.11-0.92, P=0.03).

Conclusions

Continuous HMP (initiated in donor hospital) is superior to SCS in deceased-donor kidney transplantation. Timing of HMP is important, and benefits have not been demonstrated with end-ischaemic HMP. Whilst end-ischaemic NMP is inferior to continuous HMP on indirect comparisons, further studies assessing NMP for viability assessment and therapeutic delivery are in progress.