National prospective cohort study of the burden of acute small bowel obstruction.

Background: Small bowel obstruction is a common surgical emergency, and is associated with high levels of morbidity and mortality across the world. The literature provides little information on the conservatively managed group. The aim of this study was to describe the burden of small bowel obstruction in the UK. Methods: This prospective cohort study was conducted in 131 acute hospitals in the UK between January and April 2017, delivered by trainee research collaboratives. Adult patients with a diagnosis of mechanical small bowel obstruction were included. The primary outcome was in-hospital mortality. Secondary outcomes included complications, unplanned intensive care admission and readmission within 30 days of discharge. Practice measures, including use of radiological investigations, water soluble contrast, operative and nutritional interventions, were collected. Results: Of 2341 patients identified, 693 (29·6 per cent) underwent immediate surgery (within 24 h of admission), 500 (21·4 per cent) had delayed surgery after initial conservative management, and 1148 (49·0 per cent) were managed non-operatively. The mortality rate was 6·6 per cent (6·4 per cent for non-operative management, 6·8 per cent for immediate surgery, 6·8 per cent for delayed surgery; P = 0·911). The major complication rate was 14·4 per cent overall, affecting 19·0 per cent in the immediate surgery, 23·6 per cent in the delayed surgery and 7·7 per cent in the non-operative management groups (P < 0·001). Cox regression found hernia or malignant aetiology and malnutrition to be associated with higher rates of death. Malignant aetiology, operative intervention, acute kidney injury and malnutrition were associated with increased risk of major complication. Conclusion: Small bowel obstruction represents a significant healthcare burden. Patient-level factors such as timing of surgery, acute kidney injury and nutritional status are factors that might be modified to improve outcomes.

Systematic review of the use of big data to improve surgery in low- and middle-income countries.

BACKGROUND: Technological advances have led to the generation of large amounts of data, both in surgical research and practice. Despite this, it is unclear how much originates in low- and middle-income countries (LMICs) and what barriers exist to the use of such data in improving surgical care. The aim of this review was to capture the extent and impact of programmes that use large volumes of patient data on surgical care in LMICs. METHODS: A PRISMA-compliant systematic literature review of PubMed, Embase and Google Scholar was performed in August 2018. Prospective studies collecting large volumes of patient-level data within LMIC settings were included and evaluated qualitatively. RESULTS: A total of 68 studies were included from 71 LMICs, involving 708 032 patients. The number of patients in included studies varied widely (from 335 to 428 346), with 25 reporting data on 3000 or more LMIC patients. Patient inclusion in large-data studies in LMICs has increased dramatically since 2015. Studies predominantly involved Brazil, China, India and Thailand, with low patient numbers from Africa and Latin America. Outcomes after surgery were commonly the focus (33 studies); very few large studies looked at access to surgical care or patient expenditure. The use of large data sets specifically to improve surgical outcomes in LMICs is currently limited. CONCLUSION: Large volumes of data are becoming more common and provide a strong foundation for continuing investigation. Future studies should address questions more specific to surgery.

A systematic review of the incidence of and risk factors for postoperative atrial fibrillation following general surgery.

Atrial fibrillation is a common cardiac arrhythmia and can occur de novo following a surgical procedure. It is associated with increased inpatient and long-term mortality. There is limited evidence concerning new-onset atrial fibrillation following abdominal surgery. This study aimed to identify the prevalence of and risk factors for postoperative atrial fibrillation in the general surgical population. A systematic search of the Embase, MEDLINE and Cochrane (CENTRAL) databases was conducted. Studies were included in the review if they reported cases of new-onset atrial fibrillation within 30 days of the index operation. Results were evaluated qualitatively due to substantial clinical heterogeneity. Incidence rates were pooled using a weighted random-effects meta-analysis model. A total of 835 records were initially identified, from which 32 full texts were retrieved. Following review, 13 studies were included that involved 52,959 patients, of whom 10.94% (95%CI 7.22-15.33) developed atrial fibrillation. Five studies of patients undergoing oesophagectomy (n = 376/1923) had a weighted average rate of 17.66% (95%CI 12.16-21.47), compared with 7.63% (95%CI 4.39-11.98) from eight studies of non-oesophageal surgery (n = 2927/51,036). Identified risk factors included: increasing age; history of cardiac disease; postoperative complications, particularly, sepsis, pneumonia and pleural effusions. New-onset postoperative atrial fibrillation is common, and is more frequent after surgery involving the thorax. Future work should focus on stratifying risk to allow targeted prophylaxis of atrial fibrillation and other peri-operative complications.

Resource variation in colorectal surgery: a national centre level analysis.

AIM: Delivery of quality colorectal surgery requires adequate resources. We set out to assess the relationship between resources and outcomes in English colorectal units. METHOD: Data were extracted from the Association of Coloproctology of Great Britain and Ireland resource questionnaire to profile resources. This was correlated with Hospital Episode Statistics outcome data including 90-day mortality and readmissions. Patient satisfaction measures were extracted from the Cancer Experience Patient Survey and compared at unit level. Centres were divided by workload into low, middle and top tertile. RESULTS: Completed questionnaires were received from 75 centres in England. Service resources were similar between low and top tertiles in access to Confidential Enquiry into Patient Outcome and Death (CEPOD) theatre, level two or three beds per 250 000 population or the likelihood of having a dedicated colorectal ward. There was no difference in staffing levels per 250 000 unit of population. Each 10% increase in the proportion of cases attempted laparoscopically was associated with reduced 90-day unplanned readmission (relative risk 0.94, 95% CI 0.91-0.97, P < 0.001). The presence of a dedicated colorectal ward (relative risk 0.85, 95% CI 0.73-0.99, P = 0.040) was also associated with a significant reduction in unplanned readmissions. There was no association between staffing or service factors and patient satisfaction. CONCLUSION: Resource levels do not vary based on unit of population. There is benefit associated with increased use of laparoscopy and a dedicated surgical ward. Alternative measures to assess the relationship between resources and outcome, such as failure to rescue, should be explored in UK practice.

Longitudinal analysis of reporting and quality of systematic reviews in high-impact surgical journals.

BACKGROUND: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement aims to optimize the reporting of systematic reviews. The performance of the PRISMA Statement in improving the reporting and quality of surgical systematic reviews remains unclear. METHODS: Systematic reviews published in five high-impact surgical journals between 2007 and 2015 were identified from online archives. Manuscripts blinded to journal, publication year and authorship were assessed according to 27 reporting criteria described by the PRISMA Statement and scored using a validated quality appraisal tool (AMSTAR, Assessing the Methodological Quality of Systematic Reviews). Comparisons were made between studies published before (2007-2009) and after (2011-2015) its introduction. The relationship between reporting and study quality was measured using Spearman's rank test. RESULTS: Of 281 eligible manuscripts, 80 were published before the PRISMA Statement and 201 afterwards. Most manuscripts (208) included a meta-analysis, with the remainder comprising a systematic review only. There was no meaningful change in median compliance with the PRISMA Statement (19 (i.q.r. 16-21) of 27 items before versus 19 (17-22) of 27 after introduction of PRISMA) despite achieving statistical significance (P = 0·042). Better reporting compliance was associated with higher methodological quality (rs = 0·70, P < 0·001). CONCLUSION: The PRISMA Statement has had minimal impact on the reporting of surgical systematic reviews. Better compliance was associated with higher-quality methodology.

Pharmacological management to prevent ileus in major abdominal surgery: a systematic review and meta-analysis.

BACKGROUND: Prolonged ileus is a common complication following gastrointestinal surgery, with an incidence of up to 40 %. Investigations examining pharmacological treatment of ileus have proved largely disappointing; however, recently, several compounds have been shown to have benefited when used as prophylaxis to prevent ileus. OBJECTIVE: This review aimed to evaluate the safety and efficacy of compounds which have been recently developed or repurposed to reduce bowel recovery time, thereby preventing ileus. DATA SOURCES: Data were taken from a systematic review of the MEDLINE, EMBASE and Cochrane Library Databases, in addition to manual searching of reference lists up to April 2015. No limits were applied. STUDY SELECTION: Only randomized trials were eligible for inclusion. INTERVENTIONS: Opioid receptor antagonists, ghrelin receptor agonists and serotonin receptor agonists used for the prevention of postoperative ileus in gastrointestinal surgery. MAIN OUTCOME MEASURES: Outcomes of time to first defecation, first flatus and composite bowel recovery endpoints (GI2 and GI3) were used to determine efficacy. Pooled treatment effects were presented as the standard mean difference or as hazard ratios alongside the corresponding 95 % confidence intervals. Risk of bias was assessed using the Cochrane risk of bias framework. RESULTS: A total of 17 studies were included in the final analysis. The µ-opioid receptor antagonist alvimopan and serotonin receptor agonists appeared to significantly shorten the duration of ileus. The use of Ghrelin receptor agonists did not appear to have any effect in five trials. No publication bias was detected. LIMITATIONS: Most of the trials were poorly reported and of mixed quality. Future studies must focus on the development of a set of core outcomes. CONCLUSIONS: There is evidence to make a strong recommendation for the use of alvimopan in major gastrointestinal surgery to reduce postoperative ileus. Further randomized trials are required to establish whether serotonin receptor agonists are of use. Identifying a low-cost compound to promote bowel recovery following surgery could reduce complications and shorten duration of hospital admissions.

A Randomised Assessment of Trainee Doctors' Understanding and Interpretation of Diagnostic Test Results.

INTRODUCTION: Doctors are unfamiliar with diagnostic accuracy parameters despite routine clinical use of diagnostic tests to estimate disease probability. METHODS: Trainee doctors completed a questionnaire exploring their understanding of diagnostic accuracy parameters; ability to calculate post-test probability of a common surgical condition (appendicitis) and their perceptions on training in this area. To determine whether the method of information provision altered interpretation, trainees were randomised to receive diagnostic test information in three ways: positive test only; positive test with specificity and sensitivity; positive test with positive likelihood ratio in layman terms. RESULTS: 326 candidates were recruited across 30 training sessions. Trainees scored a median of three out of seven in questions concerning knowledge of diagnostic accuracy parameters. This was affected neither by training level (P = 0.737) nor by experience in acute general surgery (P = 0.738). 30 (11.8%) candidates correctly estimated post-test probability; with 86.6% overestimating this value. Neither level of training (P = 0.180) nor experience (P = 0.242) influenced the accuracy of the estimate. Provision of the ultrasound scan results in different ways was not associated with likelihood of a correct response (P = 0.857). CONCLUSION: This study highlights the deficiencies in trainee doctors' understanding and application of diagnostic tests results. Most trainees over-estimated disease probability, increasing the risk of unnecessary intervention and treatment.

Targeting the endoplasmic reticulum mediates radiation sensitivity in colorectal cancer.

BACKGROUND: Radiotherapy is an established treatment modality for early and locally advanced rectal cancer as part of short course radiotherapy and long course chemoradiotherapy. The unfolded protein response (UPR) is a cellular stress response pathway often activated in human solid tumours which has been implicated in resistance to both chemotherapy and radiotherapy. This research has investigated whether the UPR pathway is upregulated in ex-vivo samples of human colorectal cancer and characterised the interaction between radiotherapy and UPR activation in two human colorectal cancer cell lines in vitro. METHODS: In vitro UPR expression was determined in response to clinical doses of radiotherapy in both the human colorectal adenocarcinoma (HT-29) cell line and a radio-resistant clone (HT-29R) using western blotting and quantitative polymerase chain reaction. The UPR was induced using a glucose deprivation culture technique before irradiation and radiosensitivity assessed using a clonogenic assay. Ex-vivo human colorectal cancer tissue was immuno-histochemically analysed for expression of the UPR marker glucose regulated protein 78 (GRP-78). RESULTS: The UPR was strongly up regulated in ex-vivo human colorectal tumours with 36 of 50 (72.0%) specimens demonstrating moderate to strong staining for the classic UPR marker GRP-78. In vitro, therapeutic doses of radiotherapy did not induce UPR activation in either radiosensitive or radioresistant cell lines. UPR induction caused significant radiosensitisation of the radioresistant cell line (HT-29R SF2Gy=0.90 S.E.M. +/-0.08; HT-29RLG SF2Gy=0.69 S.E.M. +/-0.050). CONCLUSION: This suggests that UPR induction agents may be potentially useful response modifying agents in patients undergoing therapy for colorectal cancer.