Consensus abstractBackground: The management of primary rectal cancer beyond total mesorectal excision planes (PRCbTME) and recurrent rectal cancer (RRC) is challenging. There is global variation in standards and no guidelines exist. To achieve cure most patients require extended, multivisceral, exenterative surgery, beyond conventional total mesorectal excision planes. The aim of the Beyond TME Group was to achieve consensus on the definitions and principles of management, and to identify areas of research priority. Methods: Delphi methodology was used to achieve consensus. The Group consisted of invited experts from surgery, radiology, oncology and pathology. The process included two international dedicated discussion conferences, formal feedback, three rounds of editing and two rounds of anonymized web- Executive summaryThe executive summary supports the need for standardization of care and a collaborative, cross-discipline consensus statement. Burden of disease:There are 14 000 new rectal cancers per year in the UK, 40 000 in the USA and under half a million new cases per year globally. Of these, 5-10 per cent have invaded adjacent organs at presentation and 10 per cent recur following primary surgery. Complexity of surgery:Major, exenterative, multivisceral resections require specialist multiprofessional care. The surgical procedures are time-consuming (up to 12 h) and are associated with prolonged length of hospital stay (between 10 and 30 days). Long-term 5-year survival rates vary between 30 and 50 per cent. Adverse event rates have been reported in up to 50 per cent of patients. Superspecialist training of surgeons within a multidisciplinary team is required. Inappropriate worldwide variation in practice:There is a wide range of practice from non-specialist and specialist centres, with unequal access to care across global settings. These include differing referral selection criteria, where patients are often denied potentially curative treatment. When surgery is offered, the outcome is neither captured by the national databases nor audited locally. * Collaborating members are shown at the end of the article. 1010The Beyond TME Collaborative Standardization of definitions: Definitions for the rectum, for primary rectal cancer beyond conventional total mesorectal excision planes, and for recurrent rectal cancer have been defined heterogeneously in the literature and between different institutions, leading to a clear requirement for standardization of the exact definition of these terms.The need for policy: Delay in diagnosis is common and inequalities exist in referral patterns based on geography, with no clear clinical guidelines. No current guidelines exist for these patients, despite the significant burden, cost of surgery, morbidity and national variations in care.Resource impact: The cost-effectiveness of the complex assessments and interventions requires further research. The quality of life and morbidity from non-operative management are unknown. There is a need for specialist training of the mul...

The application of a cut-off value for V˙O2 at AT of <10.2 ml/kg/min in patients undergoing major hepatic resection may be useful for predicting which patients will experience morbidity.

The consensus process has provided guidance for the management of patients with PRC-bTME or RRC, taking into account global variations in surgical techniques and technology. It has further identified areas of research priority.

Aim We aim to compare machine learning with neural network performance in predicting R0 resection (R0), length of stay > 14 days (LOS), major complication rates at 30 days postoperatively (COMP) and survival greater than 1 year (SURV) for patients having pelvic exenteration for locally advanced and recurrent rectal cancer. Method A deep learning computer was built and the programming environment was established. The PelvEx Collaborative database was used which contains anonymized data on patients who underwent pelvic exenteration for locally advanced or locally recurrent colorectal cancer between 2004 and 2014. Logistic regression, a support vector machine and an artificial neural network (ANN) were trained. Twenty per cent of the data were used as a test set for calculating prediction accuracy for R0, LOS, COMP and SURV. Model performance was measured by plotting receiver operating characteristic (ROC) curves and calculating the area under the ROC curve (AUROC). Results Machine learning models and ANNs were trained on 1147 cases. The AUROC for all outcome predictions ranged from 0.608 to 0.793 indicating modest to moderate predictive ability. The models performed best at predicting LOS > 14 days with an AUROC of 0.793 using preoperative and operative data. Visualized logistic regression model weights indicate a varying impact of variables on the outcome in question. Conclusion This paper highlights the potential for predictive modelling of large international databases. Current data allow moderate predictive ability of both complex ANNs and more classic methods.

Background The multidisciplinary perioperative and anaesthetic management of patients undergoing pelvic exenteration is essential for good surgical outcomes. No clear guidelines have been established, and there is wide variation in clinical practice internationally. This consensus statement consolidates clinical experience and best practice collectively, and systematically addresses key domains in the perioperative and anaesthetic management. Methods The modified Delphi methodology was used to achieve consensus from the PelvEx Collaborative. The process included one round of online questionnaire involving controlled feedback and structured participant response, two rounds of editing, and one round of web-based voting. It was held from December 2019 to February 2020. Consensus was defined as more than 80 per cent agreement, whereas less than 80 per cent agreement indicated low consensus. Results The final consensus document contained 47 voted statements, across six key domains of perioperative and anaesthetic management in pelvic exenteration, comprising preoperative assessment and preparation, anaesthetic considerations, perioperative management, anticipating possible massive haemorrhage, stress response and postoperative critical care, and pain management. Consensus recommendations were developed, based on consensus agreement achieved on 34 statements. Conclusion The perioperative and anaesthetic management of patients undergoing pelvic exenteration is best accomplished by a dedicated multidisciplinary team with relevant domain expertise in the setting of a specialized tertiary unit. This consensus statement has addressed key domains within the framework of current perioperative and anaesthetic management among patients undergoing pelvic exenteration, with an international perspective, to guide clinical practice, and has outlined areas for future clinical research.