O-OGC02 Stage Migration in Newly Diagnosed Oesophago-gastric Cancer during the first wave of COVID-19 Pandemic

Background

Covid-19 has significantly disrupted elective and emergency health care provision including cancer care within the UK. The aim of the study was to investigate the impact of the pandemic on the staging of oesophago-gastric cancers at presentation, determine the time delay in performing gastroscopy and the multidisciplinary team (MDT) treatment outcomes.

Methods

A retrospective cohort study of all newly diagnosed oesophago-gastric cancers (adenocarcinoma and squamous cell carcinoma) in a single regional MDT was performed between 1st October 2019 and 30th September 2020. Electronic records were interrogated and patients dichotomised into two groups with those presenting before the introduction of the UK national lockdown of 23^rd March 2020 compared to those presenting post-lockdown.

Results

349 new oesophago-gastric cancer patients were discussed in the MDT (192 pre-lockdown versus 157 post-lockdown). Demographics were evenly matched between the two groups. More patients presented as an emergency admission post-lockdown (28.0% vs 12.5%, p < 0.001). Median waiting time for gastroscopy was longer post-lockdown (23 vs 14 days, p = 0.035). Metastatic disease at presentation was more frequent post-lockdown (47.8% vs 33.3%, p = 0.008). Overall, more patients had a palliative rather than curative treatment intent post-lockdown (71.3% vs 57.8%, p = 0.005).

Conclusions

The Covid-19 pandemic has had a significant negative effect on the stage of oesophago-gastric cancers at presentation. This has translated into more patients receiving palliative treatment and ultimately having a poorer prognosis. This study highlights the importance of maintaining cancer services during the Covid-19 pandemic.

P-OGC74 Effect of pre-operative anaemia on short-term outcomes following oesophagectomy: a 10-year retrospective cohort study

Background

Pre-operative anaemia is associated with increased length of hospital stay, requirement for allogenic blood transfusion, post-operative complications and mortality. Oesophagectomy is a complex procedure associated with significant physiological insult, thus pre-operative patient optimisation is imperative to improve clinical outcomes. This study aimed to determine the impact of pre-operative anaemia on short-term outcomes following oesophagectomy for benign and malignant disease. 

Methods

A retrospective cohort study of all oesophagectomies performed in a single tertiary referral centre between 1 January 2010 and 31 December 2019 was performed. Patients were identified from a prospectively collected database and individual patient electronic records were interrogated. Patients were dichotomised into two groups, based on the most recent pre-operative haemoglobin. Patients with pre-operative anaemia (haemoglobin &lt;130mg/L in males and &lt;120mg/L in females) were compared to those without pre-operative anaemia. Patients with missing data were excluded from the study. Patients were followed up for a median of 32 months (IQR 18-66).

Results

Of 352 patients eligible for inclusion, 173 (49.1%) patients were anaemic immediately pre-operatively. Patients with pre-operative anaemia were older (66 vs. 64 years, p = 0.031), with a lower anaerobic threshold (11.7 vs. 12.3ml/min/kg, p = 0.011), and were significantly more likely to have undergone neoadjuvant chemotherapy (91.3% vs. 78.8%, p &lt; 0.001). Patient comorbidities and disease-related characteristics were similar between the two groups. Patients with pre-operative anaemia were significantly more likely to require post-operative blood transfusion (34.7% vs. 16.8%; p &lt; 0.001). However, pre-operative anaemia was not associated with increased post-operative complications, intensive care admission, length of hospital stay, or 30- and 90-day mortality rates following oesophagectomy.

Conclusions

Patients with anaemia immediately prior to undergoing an oesophagectomy were significantly more likely to require post-operative blood transfusion. However, pre-operative anaemia was not associated with an increased rate of post-operative morbidity or mortality. In addition, pre-operative iron transfusion is becoming increasingly utilised to minimise the incidence of pre-operative anaemia: this was not analysed in this study.

P-O08 Effect of socioeconomic deprivation on clinical characteristics and outcomes of patients undergoing an emergency appendectomy

Background

Appendicectomy is one of the commonest emergency general surgical operations performed.  Previous studies have shown that socioeconomic status (SES) impact outcomes in a number of diseases.  Currently, there is no study analysing the impact of SES on the outcome of appendectomy.   Our aim was to compare the clinical characteristics and outcomes of adults having an emergency appendectomy between deprived and less deprived SES groups.  

Methods

A multicentre retrospective observational study of all adult patients who had an emergency appendectomy across four hospitals (two district general and two tertiary care hospitals) between August 2018 and November 2020 was performed.  Patients were identified through pathology records.  Data was extracted from electronic records for demographics, pre-operative (peak) blood results, pre and post-operative imaging, operative details and the clinical outcomes.  Patient’s residential address was used to calculate Scottish Index of Multiple Deprivation (SIMD).  The patients were grouped by SIMD into a more deprived SES group (SIMD 1-5) and a less deprived SES group (SIMD 6-10) and results compared.

Results

A total of 1,105 patients (57.5% male) were included.  Median age was lower in the more deprived group (35 vs 40 years, p &lt; 0.001).   The less deprived group were more likely to be fitter: ASA-1 grade 51.6% vs 43.5%, p = 0.008.  There were fewer appendectomies in most deprived decile compared to the least deprived decile (5.2 vs 11.3 per 10,000 population per year, p &lt; 0.001).   There was no difference in inflammatory markers, pre-operative imaging, surgical approach, severity of appendicitis and the median length of stay (3 days).  However, there were more surgical site infection in the more deprived group (3.4% vs 0.9%, p = 0.006).

Conclusions

This study demonstrates that SES does impact on the age of presentation and incidence of appendectomy.  Surgical site infection were seen more frequently in the more deprived patients undergoing emergency appendectomy.  This may be a reflection of the underlying comorbidities.

P-O13 Spontaneous Splenic Rupture as first presentation of Chronic Myeloid Leukaemia

Background

Although rare, spontaneous splenic rupture (SSR) is a potentially life threatening condition and most commonly associated with infection and malignancy. Haematological malignancies are an important differential diagnosis and among these chronic myeloid leukaemia (CML) has one of the highest associations with SSR.

Methods

This case report follows a previously fit and healthy thirty-three year old gentleman who presented to accident and emergency with one day history of sudden onset, severe, left upper quadrant pain. CT of the abdomen and pelvis including an arterial phase, confirmed splenic rupture with moderate volume haemo-peritoneum, but no active bleeding. White cell count (WCC) was 225.8 x10^9/l and blood film confirmed suspicion of haematological malignancy. The patient was haemodynamically stable and therefore transferred to the surgical high dependency unit for observation and conservative management. He was commenced on hydroxycarbamide on the advice of haematology.

Results

Genetic screening detected BCR-ABL1 and Philadelphia chromosome; this along with bone marrow aspirate confirmed diagnosis of CML. His WCC decreased with hydroxycarbamide therapy. He made good clinical progress and was discharged home with haematology follow up. Hydroxycarbamide has since been stopped and he has been initiated on Imatinib therapy. His WCC has returned to normal and he has remained well with no further complications.

Conclusions

SSR is an extremely rare first presentation of CML. Given its associated morbidity and mortality, it should remain an important differential diagnosis in patients presenting acutely to the General Surgeon with abdominal pain and shock, especially in those with a known underlying haematological malignancy.

P-OGC72 Morbidity following oesophagectomy: the long-term re-operation rate after surgical resection in a Scottish tertiary centre

Background

Oesophagectomy remains the best curative option for early stage or locally advanced cancers of the oesophagus and gastro-oesophageal junction. The long-term morbidity associated with oesophagectomy is poorly understood. This study aimed to describe re-operation rates for oesophagectomy-related complications, performed beyond 90 days from index oesophagectomy.

Methods

A retrospective cohort study of all oesophagectomies performed in a single tertiary centre between 01 January 2010 and 31 December 2019 was performed. Electronic records were interrogated and patients dichotomised into two groups, with patients that underwent re-operation at ≥ 90 days after oesophagectomy for complications directly related to the index procedure compared to patients who did not have further surgery. All endoscopic interventions were excluded from analysis. The median length of follow-up was 34 months (IQR 20-67).

Results

343 patients were eligible for analysis. Patient demographics and index operative approach were similar between the two groups. Beyond 90 days from surgery, 8.7% of patients (30/343) required a further operation for complications directly related to oesophagectomy. The median time to re-operation was 15.5 months (IQR 12-29). 28 out of a total of 38 re-operations performed (73.7%) were for wound complications (including 15 incisional hernia repairs and 7 excision of stitch sinus). Development of a wound infection in the immediate post-operative period was associated with an increased rate of later re-operation (16.7% vs. 4.8%, p = 0.022).

Conclusions

A small but significant number of patients require re-operation following oesophagectomy beyond 90 days of surgery. This should form part of the pre-operative informed consent discussion in order to fully appraise patients and manage expectations. Reducing the incidence of early wound infection appears to be a key factor.

P-OGC69 Incidence, presentation and long-term sequelae of hiatus hernia after oesophagectomy: a 10-year retrospective cohort study

Background

Hiatus hernia after oesophagectomy is a rare but recognised event, with potentially life-threatening consequences when there is bowel compromise. This 10-year retrospective cohort study aimed to identify the incidence and evaluate the clinical presentation and long-term management of hiatus hernia after oesophagectomy.

Methods

We conducted a retrospective analysis of all oesophagectomies performed in a single tertiary centre over a 10-year study period between 2010 and 2019. Demographics, details of the initial procedure and long-term outcomes were analysed. Patients that underwent post-operative computed tomography (CT) imaging at ≥ 12 months post-operatively were included in analysis, with all CT scans independently reviewed by a radiologist.

Results

212 patients were eligible for analysis. 25% (53/212) of patients developed a hiatus hernia post oesophagectomy. Demographic data were similar between patients who developed a hernia compared to those who did not. 75.5% (40/53) of post-operative hiatus hernias developed after transhiatal oesophagectomy (p &lt; 0.001), and patients with post-operative hiatus hernia had a higher BMI (p = 0.009); this association was confirmed on multivariate analysis. Hiatus hernia was frequently under-reported, with only 58.5% (31/53) mentioned on the formal CT report. 81.1% of patients (43/53) were asymptomatic. Operative intervention was only performed in 1 patient presenting with small bowel obstruction as an emergency.

Conclusions

Hiatus hernia is a potentially clinically significant and under recognised long-term complication following oesophagectomy, with a significantly higher incidence following transhiatal oesophagectomy and in obese patients. With increasing long-term survival after surgical resection and its preponderance to be found incidentally on cross-sectional imaging, judicious screening for hiatus hernia is warranted to prevent fatal complications. 

P-OGC78 One year experience of a newly established super green ERAS pathway for performing oesophago-gastric cancer resections during the Covid-19 pandemic

Background

Surgical oncology services in the UK have been impacted by the COVID-19 pandemic.  Various strategies have been employed in an attempt to continue cancer resectional surgery   during the pandemic.  This study examined our institution’s experience and outcomes with a newly established Super Green ERAS pathway for oesophago-gastric (OG) cancer resections during the pandemic.

Methods

A retrospective cohort study of consecutive patients who had a resection for OG cancer performed over a 12-month period beginning from the date of the first UK National Lockdown of 23 March 2020.  Barring two intervals each lasting 3 weeks, urgent elective cancer surgery continued on our mixed hot and cold site through the establishment of a Super Green ERAS pathway.

Patients were confirmed COVID-19 negative within 72 hours pre-admission and retested  72-hourly post-op. 14 days self-isolation pre-admission was mandated.  Patients not complying had their surgery postponed. Transhiatal oesophagectomy was the preferred approach for oesophagectomy during the pandemic. 

Results

45 resections (33 oesophagectomies, 10 gastrectomies and 2 trial of dissections) were performed.  37 (82.2%) patients were male with a median age of 64 (IQR 58-71) years.   3 patients were postponed due to non-adherence with self-isolation.

No patients tested positive for COVID-19 post-operatively, hence, there was no COVID-19-related morbidity. Nine patients developed pneumonia. Seven patients had an anastomotic leak, all of whom were successfully rescued. One patient required a clamshell thoracotomy due to intra-operative mediastinal bleeding followed by a return to theatre for reconstruction 48hrs later.  Median length of stay was 12 (IQR 9-18) days. There was no in-hospital mortality.

Conclusions

OG cancer resections can be performed safely despite COVID-19, with favorable clinical outcomes when a Super Green ERAS pathway is strictly adhered to.   Implementation of such pathways will enable surgical oncology services, including OG cancer resections, to continue to ensure best possible outcomes for cancer patients despite any future waves of the COVID-19 pandemic.

P-O14 The predictive role of pre-operative liver function tests in outcomes following emergency appendicectomy

Background

Acute appendicitis remains one of the most common diagnoses in emergency general surgery, with recent evidence from the COMMA trial confirming that appendicectomy is the cornerstone of definitive management in most patients. With a wide range of severity and of patient physiology, complications are a burden to patients and the health service. We hypothesised that liver function tests have predictive value for complications following emergency appendicectomy.

Methods

A multicentre retrospective observational study was carried out across 4 hospitals (2 teaching centres and 2 district general hospitals) for adult patients who underwent emergency appendectomy between August 2018 and November 2020.  Patients were identified through pathology records and data was extracted from electronic case records for patient demographics, pre-operative routine laboratory results, operative details, and clinical outcomes. Peak perioperative liver function parameters were analysed using unpaired two-way T-tests, Pearson’s correlation coefficient, ANOVA and multivariate regression to determine their relationship with conversion to open surgery, superficial and deep surgical site infection (SSI), length of stay (LOS) and 30-day re-admission rates.

Results

Of 1131 patients included, 57.4% were male, 80.5% were laparoscopic, with 7.3% converted to open, 10.8% performed open, and 1.5% by laparotomy. Mean LOS was 3.81 (SD4.0) days, 6.3% readmission rate, with 2.3% superficial SSI and 5.0% deep SSI.

ALP was higher in patients with superficial SSI (p &lt; 0.001). Lower ALT was associated with wound dehiscence (p &lt; 0.001). Bilirubin, AST and ALT were lower in patients with chest infections (p &lt; 0.001). ALP correlated with increased LOS (p &lt; 0.001).

On multivariable regression, ALP was associated with superficial SSI (p &lt; 0.001), and LOS (p &lt; 0.001). ROC curve analysis demonstrated AUC of 0.655 for ALP and superficial SSI.

Conclusions

Emergency appendicectomy is completed laparoscopically in more than 80% of patients and complication rates are acceptable. Routine liver function tests were associated with important clinical outcomes including superficial SSI, wound dehiscence, chest infection, LOS and readmission rate. Patients who had superficial SSI, wound dehiscence, chest infection and readmission with 30 days had lower transaminase levels compared with those with uncomplicated recovery.

P-OGC77 Why curative treatment rates are so low for stage I/II Oesophago-gastric cancer in the West of Scotland? – A five year review

Background

Over the last decade, quality performance indicators (QPIs) have been used to drive improvements in cancer care in Scotland.  QPI-11 targets curative treatment rates for oesophago-gastric (OG) cancer and this target has been consistently missed.  This study aimed to investigate why patients with potentially curable Stage I and II OG cancer did not receive curative treatment. 

Methods

The West of Scotland MCN database was interrogated for patients with newly diagnosed stage I and II OG cancer between January 2015 and December 2019 to identify those patients who did not have curative treatment.  Electronic records were then analyzed and the reason for the non curative treatment recorded.

Results

260 patients (mean age 78.3 ± 9 years; 114 (43.8%) female) were identified. Median Scottish Index of Multiple Deprivation was 4 (IQR 2-7).   There were 159 (61.2%) oesophageal cancers, 196 (75.4%) adenocarcinomas and 174 (66.9%) were Stage II cancers.  Formal CPEX fitness was assessed in only 20 patients (7.7%).  Reasons for curative treatment not being received were as follows: not clinically fit (n = 216 (83.1%)); patient declined curative treatment (n = 17 (6.5%)); disease progression (n = 16 (6.2%)) and identification of synchronous cancers (n = 9 (3.5%)).

Conclusions

Lack of fitness for radical treatment is the predominant reason for Stage I and II OG cancer patients in the West of Scotland not being treated with curative intent.  This may be related to the previously described “West of Scotland” effect on health comorbidities.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

SP2.2.11Improving the quality of the documented weekend surgical handover: Implementation of a handover sticker within an urban teaching hospital

Aim

Effective, high-quality patient handovers between the surgical team are essential for safe transfer of responsibility for patient care whilst ensuring continued patient-safety and supporting good clinical governance. Weekend handovers provide a particular challenge, with error potential, when patients are cared for by multiple different healthcare professionals. This project aimed to improve the documentation of the weekend handover for the surgical inpatients of a busy UK teaching hospital.

Method

Quality Improvement project performed within a single General Surgical department between August and October 2020. An initial casenote audit on 3 consecutive Fridays compared available handover information against RCS guidance. A comprehensive surgical weekend handover sticker was designed and all members of the surgical team educated in its use. Following sticker introduction, handover quality was similarly re-audited. **=p&lt;0.00001 using Chi-squared/Fisher exact.

Results

138 inpatient records were evaluated in cycle 1 and 135 in cycle 2, with the proportion containing a weekend handover increased post-intervention (96 vs. 82%,p=0.0004). Handover quality improved following sticker introduction with more frequent documentation of: diagnosis (96 vs. 21%**); need for imaging review (94 vs. 29%**); intravenous fluid plan (84 vs. 21%**); blood test requirements (94 vs. 24%**); mode of nutrition (90 vs. 24%**); antibiotics (90 vs. 30%**); drug monitoring (90 vs. 1%**); discharge planning (94 vs. 44%**) and escalation plan (87 vs. 0%**).

Conclusion

Introduction of a sticker has significantly improved the quality of documented handover available to the responsible on-call team. Future work will assess sticker impact on quality of care and clinical outcomes.

EP.WE.410Appendicectomy during the COVID-19 pandemic: an assessment of the change in practice within the West of Scotland

Aims

The Covid-19 pandemic has significantly impacted emergency and elective surgical activities. Multiple surgical professional bodies initially recommended appendicitis be managed conservatively or with judicious open surgery to mitigate potential risks with Covid-19 transmission. This study compares the investigation, operative findings and outcomes of patients who underwent appendicectomy before and after the National lockdown.

Methods

A multicentre retrospective cohort study of patients who had emergency appendicectomy in four West of Scotland hospitals between September 2019 and November 2020. Electronic records were interrogated and patients dichotomised into two groups with those presenting before the introduction of the UK National lockdown of 23^rd March 2020 compared to those presenting post-lockdown.

Results

A total of 559 appendicectomies were performed (280 pre-lockdown and 279 post-lockdown) in four hospitals and included in the analyses. More males than females had appendicectomy in the post-lockdown period (60.6% vs 52.1%, p 0.044). Pre-operative CT scanning was performed more often post-lockdown (71.7% vs 56.8%, p < 0.001) and an open approach was adopted more frequently post-lockdown (19.0% vs 3.6%, p < 0.001). The proportion of operations for complicated appendicitis increased post-lockdown (31.9% vs 22.1%, p = 0.009). Median hospital stay was equal in both groups (3 vs 3 days, p = 0.787). Post-operative complication rates were similar in both groups apart from a higher 30-day re-admission rate post-lockdown (7.9% vs 3.6%, p = 0.028).

Conclusion

Covid-19 has resulted in significant modifications to the pre-operative work-up and surgical approach to patients undergoing emergency appendicectomy. Whilst the proportion of patients with complicated appendicitis has increased post-lockdown, overall clinical outcomes remain similar.

EP.FRI.692 Gender differences in the age and outcomes of appendicectomy patients

Aims

Appendicectomy is one of the commonest emergency General Surgical operations performed. However, there exists minimal published literature exploring whether there are differences between males and females undergoing appendicectomy.  This study aimed to investigate the demographics, pre-operative investigation, intra-operative findings and clinical outcomes between both genders having an emergency appendicectomy.

Methods

A multicentre retrospective cohort study of all patients who had an emergency appendicectomy within four UK hospitals between September 2019 and November 2020. Electronic records were interrogated and patients dichotomised by gender and the results compared.

Results

559 emergency appendicectomies (315 (56.4%) male and 244 (43.6%) female patients) were included.  Males undergoing appendicectomy were younger (median age: 33 vs 41 years, p &lt; 0.001).  American Society of Anaesthesiologists classification was equally matched.  Whilst no difference in mean white cell or neutrophil count was identified, C-reactive protein was lower (mean 108 vs 137, p = 0.001) and bilirubin higher (mean 21 vs 15, p &lt; 0.001) in male patients pre-operatively.  Pre-operative imaging was performed more often in females: ultrasound (16.0 vs 1.3%, p &lt; 0.001) and CT scan (69.3 vs 60.3%, p = 0.029).  Male patients underwent more open surgery (13.7 vs 8.2%, p = 0.043).  The intra-operative severity of appendicitis was equally matched.  No differences in overall hospital length of stay (median 3 vs 3 days, p = 0.183), post-operative complication rates or 30-day readmission rates were identified.

Conclusions

This study demonstrates that differences exist between males and females who have emergency appendicectomy in terms of age, use of pre-operative imaging and operative approach, however, clinical outcomes are similar.

Characterization of an x-ray tube-based ultrahigh dose-rate system for in vitro irradiations

PURPOSE

To present an x-ray tube system capable of in vitro ultrahigh dose-rate (UHDR) irradiation of small < 0.3 mm samples and to characterize it by means of a plastic scintillation detector (PSD).

METHODS AND MATERIALS

A conventional x-ray tube was modified for the delivery of short UHDR irradiations. A beam shutter system with a sample holder was designed and installed in a close proximity of an x-ray tube window to enable <1 s irradiations at UHDR. The dosimetry was performed with a small 0.5-mm long 0.5-mm in diameter PSD irradiated with 80, 100, and 120 kVp beams and beam currents of 1-37.5 mA. The PSD signal was recorded at frame rates of 20 and 50 fps for shutter exposure between 100 and 1125 ms. Irradiation reproducibility was studied with the PSD. The x-ray tube irradiation setup was modeled with Monte Carlo (MC) and dose on a surface of a phantom was also measured with films. The effect of dose delivery uncertainty to 300-μm spheroids due to positioning and spheroid size was evaluated.

RESULTS

MC simulations showed good agreement with PSD measurements acquired at both frame rates of 20 and 50 fps in terms of beam temporal profile. PSD-measured dose exhibited excellent linearity as a function of instantaneous dose rate from 3.1 to 118.0 Gy/s as well as shutter exposure time from 100 and 1125 ms for all investigated beam energies. PSD absorbed dose for the 80, 100, and 120 kVp beams agreed with MC simulations to within 5%. The total delivered doses ranged from 0.4 Gy for a 1-mA, 80 kVp beam, and 100 ms shutter exposure to 166.9 Gy for a 37.5-mA, 80 kVp beam, and a 1125 ms exposure. PSD irradiation reproducibility was < 0.5%. Simulated and measured dose fall off agreed and it was steep along the axis of the shutter slit (1%/0.1 mm) and with depth (2%/0.1 mm at 1-mm depth). Spheroid positioning uncertainty of 300 μm resulted in dose difference of < 3% for x and y shifts but up to 7% uncertainty for a z-shift parallel to the beam axis. A 16% difference in spheroid size resulted in <5% dose difference in spheroid absorbed dose.

CONCLUSIONS

We have presented a cost-effective x-ray tube-based system with a beam shutter designed for in vitro UHDR delivery and reaching dose rates of up to 118.0 Gy/s. The described shutter system can be easily implemented at other institutions, which might enable new researchers to investigate the radiobiology of UHDR irradiations in vitro.

Covered stents versus balloon angioplasty for failure of arteriovenous access: a systematic review and meta-analysis

INTRODUCTION

Patients with end-stage renal disease may require arteriovenous (AV) access in the form of arteriovenous fistulae (AVFs) or arteriovenous grafts (AVGs) for haemodialysis. AV access dysfunction requires intervention such as plain balloon angioplasty or covered stents to regain patency.

AIM

To systematically review and meta-analyse the patency outcomes of covered stents in failing haemodialysis AV access, compared with balloon angioplasty.

METHODS

The review was first registered on the International Prospective Register of Systematic Reviews (CRD42018069955) before data collection. We searched six electronic databases to identify relevant randomised controlled trials (RCTs) up until August 2020, without language restriction. Two reviewers assessed the suitability and quality of studies for inclusion using the Consolidated Standards of Reporting Trials guidelines. We meta-analysed data using a random-effects model.

RESULTS

We included seven studies including 1147 patients in the systematic review, of which 867 had AVGs and 280 had AVFs. One study was an ongoing RCT. In the meta-analyses, we assessed patients with failing AVGs only. Overall risk of bias was moderate. Covered stents were associated with lower loss of patency versus angioplasty alone at 6, 12 and 24 months (OR 4.48, 95% CI 1.98 to 10.14, p<0.001; OR 4.07, 95% CI 1.74 to 9.54, p=0.001; OR 2.24, 95% CI 1.17 to 4.29, p=0.01, respectively). Covered stents afforded superior access circuit primary patency compared with angioplasty alone at 6 and 12 months (OR 1.91, 95% CI 1.31 to 2.80, p<0.001; OR 1.97, 95% CI 1.14 to 3.41, p=0.02, respectively). This was not significant at 24 months. There was no significant difference in loss of secondary patency between groups at 12 or 24 months (OR 0.74, 95% CI 0.45 to 1.23, p=0.25; OR 0.67, 95% CI 0.29 to 0.154, p=0.34, respectively).

CONCLUSION

Our results support use of covered stents over angioplasty alone, at 6, 12 and 24 months in failing AVGs. Further clinical trials are warranted.

Mortality from esophagectomy for esophageal cancer across low, middle, and high-income countries: An international cohort study

BACKGROUND

No evidence currently exists characterising global outcomes following major cancer surgery, including esophageal cancer. Therefore, this study aimed to characterise impact of high income countries (HIC) versus low and middle income countries (LMIC) on the outcomes following esophagectomy for esophageal cancer.

METHOD

This international multi-center prospective study across 137 hospitals in 41 countries included patients who underwent an esophagectomy for esophageal cancer, with 90-day follow-up. The main explanatory variable was country income, defined according to the World Bank Data classification. The primary outcome was 90-day postoperative mortality, and secondary outcomes were composite leaks (anastomotic leak or conduit necrosis) and major complications (Clavien-Dindo Grade III - V). Multivariable generalized estimating equation models were used to produce adjusted odds ratios (ORs) and 95% confidence intervals (CI95%).

RESULTS

Between April 2018 to December 2018, 2247 patients were included. Patients from HIC were more significantly older, with higher ASA grade, and more advanced tumors. Patients from LMIC had almost three-fold increase in 90-day mortality, compared to HIC (9.4% vs 3.7%, p < 0.001). On adjusted analysis, LMIC were independently associated with higher 90-day mortality (OR: 2.31, CI95%: 1.17-4.55, p = 0.015). However, LMIC were not independently associated with higher rates of anastomotic leaks (OR: 1.06, CI95%: 0.57-1.99, p = 0.9) or major complications (OR: 0.85, CI95%: 0.54-1.32, p = 0.5), compared to HIC.

CONCLUSION

Resections in LMIC were independently associated with higher 90-day postoperative mortality, likely reflecting a failure to rescue of these patients following esophagectomy, despite similar composite anastomotic leaks and major complication rates to HIC. These findings warrant further research, to identify potential issues and solutions to improve global outcomes following esophagectomy for cancer.

Comparison of short-term outcomes from the International Oesophago-Gastric Anastomosis Audit (OGAA), the Esophagectomy Complications Consensus Group (ECCG), and the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

BACKGROUND

The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA).

METHODS

The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up.

RESULTS

The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien-Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013).

CONCLUSION

Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.

536 Use of A Cost-Efficient Colonoscopy Simulation Model to Improve Endoscopy Skills During the COVID Pandemic

Introduction

The use of endoscopic simulators as a learning aid in surgical training has been well established. This has been emphasised during the challenging times of COVID-19. However, their utility for training is countered by the high cost of the equipment, with the most basic simulators costing upwards of £50,000.

Method

A simple polypectomy simulator model was created using a drain-pipe and surgical gloves. n = 9 junior doctors were timed in their ability to remove the 3 polyps from the simulator. The exercise was repeated over 6 sessions over the course of 3 weeks. Means were compared using ANOVA.

Results

There was a mean relative reduction of 75% in overall time taken to complete the task(p < 0.0001). This improvement was seen for both surgical trainees(p = 0.005) and FY1 novices(p < 0.0001) and junior doctors reported feeling more confident with basic Colonoscopic skills.

Conclusions

We have demonstrated an improvement in performance times across both surgical trainees and novices. In today’s era of COVID-19, when direct training opportunities may become more scarce, simple alternatives may become vital in ensuring progression of basic surgical skills such as endoscopy. This cheap polypectomy simulator can be easily re-created across surgical units and can be used as an adjunct to traditional endoscopic training

E6-mediated activation of JNK drives EGFR signalling to promote proliferation and viral oncoprotein expression in cervical cancer

Human papillomaviruses (HPV) are a major cause of malignancy worldwide, contributing to ~5% of all human cancers including almost all cases of cervical cancer and a growing number of ano-genital and oral cancers. HPV-induced malignancy is primarily driven by the viral oncogenes, E6 and E7, which manipulate host cellular pathways to increase cell proliferation and enhance cell survival, ultimately predisposing infected cells to malignant transformation. Consequently, a more detailed understanding of viral-host interactions in HPV-associated disease offers the potential to identify novel therapeutic targets. Here, we identify that the c-Jun N-terminal kinase (JNK) signalling pathway is activated in cervical disease and in cervical cancer. The HPV E6 oncogene induces JNK1/2 phosphorylation in a manner that requires the E6 PDZ binding motif. We show that blockade of JNK1/2 signalling using small molecule inhibitors, or knockdown of the canonical JNK substrate c-Jun, reduces cell proliferation and induces apoptosis in cervical cancer cells. We further demonstrate that this phenotype is at least partially driven by JNK-dependent activation of EGFR signalling via increased expression of EGFR and the EGFR ligands EGF and HB-EGF. JNK/c-Jun signalling promoted the invasive potential of cervical cancer cells and was required for the expression of the epithelial to mesenchymal transition (EMT)-associated transcription factor Slug and the mesenchymal marker Vimentin. Furthermore, JNK/c-Jun signalling is required for the constitutive expression of HPV E6 and E7, which are essential for cervical cancer cell growth and survival. Together, these data demonstrate a positive feedback loop between the EGFR signalling pathway and HPV E6/E7 expression, identifying a regulatory mechanism in which HPV drives EGFR signalling to promote proliferation, survival and EMT. Thus, our study has identified a novel therapeutic target that may be beneficial for the treatment of cervical cancer.

Complications and functional outcomes after ileo-anal pouch excision-a systematic review of 14 retrospective observational studies

PURPOSE

The ileo-anal pouch (IAP) has been the gold standard procedure for maintenance of bowel continuity after panproctocolectomy for ulcerative colitis, familial adenomatous polyposis or hereditary non-polyposis colorectal cancer. However, the IAP has an estimated failure rate of 13% at 10 years post-procedure (Tulchinsky et al., Ann Surg 238(2):229-34, 2003), which can result in pouch excision (P.E.). This systematic review aims to synthesise all the available studies reporting post-operative outcomes of P.E. and its impact on patient quality of life (QoL), when available, which have not previously been summarised.

METHODS

PubMed, Embase, Medline and the Cochrane library databases were searched with terms 'Pouch AND excision' OR 'Pouch AND removal' OR 'Pouch AND remove' OR 'IAP AND excision'. All studies reporting post-operative morbidity, mortality or functional outcomes in patients who had P.E. were included. Studies with < 5 patients, non-English studies and conference abstracts were excluded.

RESULTS

14 studies comprising 1601 patients were included. Overall complications varied from 18 to 63% with the most common being persistent perineal sinus (9-40%) or surgical site infection (wound-2 to 30%; intra-abdominal collection-3 to 24%). The mortality rate was between 0.58 and 1.4%. QoL is generally lower in P.E. patients compared to the normal population across various QoL measures and P.E. patients often had urinary and sexual dysfunction post-operatively.

CONCLUSIONS

There is a substantial incidence of complications after P.E.; however, there is no evidence describing QoL pre- and post-P.E. Further longitudinal research comparing QoL in patients undergoing P.E. and other treatment options such as indefinite diversion is required to definitively assess QoL post-procedure.

The human papillomavirus oncoproteins: a review of the host pathways targeted on the road to transformation

Persistent infection with high-risk human papillomaviruses (HR-HPVs) is the causal factor in over 99 % of cervical cancer cases, and a significant proportion of oropharyngeal and anogenital cancers. The key drivers of HPV-mediated transformation are the oncoproteins E5, E6 and E7. Together, they act to prolong cell-cycle progression, delay differentiation and inhibit apoptosis in the host keratinocyte cell in order to generate an environment permissive for viral replication. The oncoproteins also have key roles in mediating evasion of the host immune response, enabling infection to persist. Moreover, prolonged infection within the cellular environment established by the HR-HPV oncoproteins can lead to the acquisition of host genetic mutations, eventually culminating in transformation to malignancy. In this review, we outline the many ways in which the HR-HPV oncoproteins manipulate the host cellular environment, focusing on how these activities can contribute to carcinogenesis.

The STREAM Trial (Prostatic Artery Embolization for the Treatment of Benign Prostatic Hyperplasia) 24-Month Clinical and Radiological Outcomes

PURPOSE

To establish factors predictive of success prior to Prostate Artery Embolization (PAE) with MRI imaging.

MATERIALS AND METHODS

A prospective cohort study of 50 patients with Benign Prostatic Hyperplasia (BPH) were treated with PAE in a single institution. Patients had moderate to severe symptoms of BPH refractory to medical management for at least 6 months. Patients were imaged with multiparametric MRI imaging pre-PAE and at 3 months, 12 months and 24 months post-PAE. Clinical success was measured with IPSS, IIEF and EQ-5D-5L quality of life questionnaires.

RESULTS

The technical success was 48/50 (96%).The mean age of the group was 67 (range 54-83). The mean IPSS score pre-PAE was 21 and at 24 months was 8 (p < 0.001). There was no deterioration in erectile function. The mean volume of the prostate post-PAE was reduced at 3 and 12 months post-PAE but not significantly different at 24 months. This did not correlate with the IPSS score. Patients with median lobe enlargement has similar symptomatic improvement as those without median lobe enlargement. Internally within the prostate patients with adenomatous-dominant BPH initially did better than patients with stromal enlargement; however, at 24 months patients with stromal enlargement of the prostate improved greatest. Initial volume of the prostate was not a good predictor of clinical success.

CONCLUSION

PAE is a safe and effective treatment strategy for treating men with BPH. Patients with Adenomatous BPH clinically do better until 12 months but not at 24 months. Initial prostate volume does not affect outcome, and patients with median lobe enlargement do as well as those without.

Rationally derived inhibitors of hepatitis C virus (HCV) p7 channel activity reveal prospect for bimodal antiviral therapy

Since the 1960s, a single class of agent has been licensed targeting virus-encoded ion channels, or 'viroporins', contrasting the success of channel blocking drugs in other areas of medicine. Although resistance arose to these prototypic adamantane inhibitors of the influenza A virus (IAV) M2 proton channel, a growing number of clinically and economically important viruses are now recognised to encode essential viroporins providing potential targets for modern drug discovery. We describe the first rationally designed viroporin inhibitor with a comprehensive structure-activity relationship (SAR). This step-change in understanding not only revealed a second biological function for the p7 viroporin from hepatitis C virus (HCV) during virus entry, but also enabled the synthesis of a labelled tool compound that retained biological activity. Hence, p7 inhibitors (p7i) represent a unique class of HCV antiviral targeting both the spread and establishment of infection, as well as a precedent for future viroporin-targeted drug discovery.