Background Data: MRI assessment of rectal cancer not only assesses tumor depth and surgical resectability but also extramural disease which affects prognosis. We have observed that nonnodal tumor nodules (tumor deposits; mrTDs) have a distinct MRI appearance compared to lymph node metastases (mrLNMs). Objective: We aimed to assess whether mrTDs and mrLNMs have different prognostic implications and compare these to other known prognostic markers. Methods: This was a retrospective cohort study of 233 patients undergoing resection for rectal cancer from January 2007 to October 2015.Data were obtained from electronic records and MRIs blindly rereported. Survival was determined using Kaplan-Meier method. Prognostic markers were evaluated using Cox regression and competing risks analysis. Inter-observer agreement for mrTD was measured using Cohen Kappa. Results: On multivariable analysis, baseline mrTD/mrEMVI (extramural venous invasion) status was the only significant MRI factor for adverse survival [hazard ratio (HR) 2.36 (1.54-3.61] for overall survival, 2.37 (1.47-3.80) for disease-free survival (both P < 0.001), superseding T and N categories. mrLNMs were associated with good prognosis (HR 0.50 (0.31-0.80) P = 0.004 for overall survival, 0.60 (0.40-0.90) P = 0.014 for disease-free survival). On multivariable analysis, mrTDs/mrEMVI were strongly associated with distant recurrence ) P ≤ 0.001) whereas T and N category were not. In a subgroup analysis of posttreatment MRIs in postchemoradiotherapy patients, mrTD/mrEMVI status was again the only significant prognostic factor; furthermore those who showed a good treatment response had a prognosis similar to patients who were negative at baseline. Inter-observer agreement for detection of mrTDs was k0.77 and k0.83. Conclusions: Current MRI staging predicting T and N status does not adequately predict prognosis. Positive mrTD/mrEMVI status has greater prognostic accuracy and would be superior in determining treatment and follow-up protocols. Chemoradiotherapy may be a highly effective treatment strategy in mrTD/mrEMVI positive patients.

The utility of perfluoroctylbromide (PFOB) as a gastrointestinal contrast agent for magnetic resonance (MR) imaging was evaluated with MR examinations performed in 30 subjects (16 healthy volunteers and 14 patients). Transaxial T1-, proton density-, and T2-weighted MR images were acquired in each subject before and after the administration of PFOB. The healthy volunteers each underwent two sets of post-PFOB MR examinations, one before and one after glucagon administration. The degree of bowel marking, clarity of bowel-wall visualization, ability to distinguish bowel from adjacent parenchymal organs, and severity of phase-encoding artifacts were independently analyzed by two reviewers. Oral administration of PFOB significantly (P less than .001) increased the percentage of bowel loops with low signal intensity. Subcutaneous administration of glucagon significantly (P less than .001) increased the clarity of bowel-wall visualization on post-PFOB MR studies. The severity of phase-encoding artifacts did not change substantially after administration of PFOB or glucagon.

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Aim The SphinKeeper TM artificial bowel sphincter implant is a relatively new surgical technique for the treatment of refractory faecal incontinence. This study presents the first experience in two UK tertiary centres. Method This is a retrospective audit of prospectively collected clinical data in relation to technique, safety, feasibility and short-term effectiveness from patients undergoing surgery from January 2016 to April 2019. Baseline data, intra-operative and postoperative complications, symptoms [using St Mark's incontinence score (SMIS)] and radiological outcomes were analysed. Results Twenty-seven patients [18 women, median age 57 years (range 27-87)] underwent SphinKeeper. In 30% of the patients, the firing device jammed and not all prostheses were delivered. There were no intra-operative complications and all patients were discharged the same or the following day. SMIS significantly improved from baseline [median À6 points (range À12 to +3); P < 0.00016] with 14/27 (51.9%) patients achieving a 50% reduction in the SMIS score. On postoperative imaging, a median of seven prostheses (range 0-10) were identified with a median of five (range 0-10) optimally placed. There was no relationship between number of well-sited prostheses on postoperative imaging and categorical success based on 50% reduction in SMIS (v 2 test, P = 0.79). Conclusion SphinKeeper appears to be a safe procedure for faecal incontinence. Overall, about 50% patients achieved a meaningful improvement in symptoms. However, clinical benefit was unrelated to the rate of misplaced/migrated implants. This has implications for confidence in proof of mechanism and also the need for technical refinement.

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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.