The Incidence of Low Anterior Resection Syndrome as Assessed in an International Randomized Controlled Trial (MRC/NIHR ROLARR).

OBJECTIVE: To investigate the incidence of LARS in patients undergoing elective anterior resection within the MRC/NIHR ROLARR trial and to explore perioperative variables that might be associated with major LARS. SUMMARY BACKGROUND DATA: Sphincter-preserving rectal cancer surgery is frequently accompanied by defaecatory dysfunction known as Low anterior resection syndrome (LARS). This is distressing for patients and is an unmet clinical challenge. METHODS: An international, retrospective cohort study of patients undergoing anterior resection within the ROLARR trial was undertaken. Trial participants with restoration of gastrointestinal continuity and free from disease recurrence completed the validated LARS questionnaire between August 2015 and April 2017. The primary outcome was the incidence of LARS and secondary outcome was severity (minor versus major). RESULTS: LARS questionnaires were received from 132/155 (85%) eligible patients. The median time from surgery to LARS assessment was 1065 days (range 174-1655 d). The incidence of LARS was 82.6% (n = 109/132), which was minor in 26/132 (19.7%) and major in 83/132 (62.9%). The most common symptoms were incontinence to flatus (n = 86/132; 65.2%) and defaecatory clustering (88/132; 66.7%). In a multivariate model, predictors of major LARS were: 1 cm decrease in tumor height above the anal verge (OR = 1.290, 95% CI: 1.101,1.511); and an ASA grade greater than 1 (OR = 2.920, 95% CI: 1.239, 6.883). Treatment allocation (laparoscopic vs robotic) did not predict major LARS. CONCLUSIONS: LARS is a common after rectal cancer surgery and patients should be appropriately counselled preoperatively, particularly before surgery for low tumors or in comorbid populations.

Noninvasive vagus nerve stimulation to reduce ileus after major colorectal surgery: early development study.

AIM: Vagus nerve stimulation has emerged as a plausible intervention to reduce ileus after surgery. An early development study was undertaken with the aim of exploring the feasibility of self-administered, noninvasive vagus nerve stimulation (nVNS) after major colorectal surgery. METHOD: A parallel-group, randomized controlled trial was undertaken between 1 January 2018 and 31 August 2019. Forty patients undergoing colorectal surgery for malignancy were allocated equally to Sham and Active stimulation groups. Electrical vagus nerve stimulation was self-administered bilaterally over the cervical surface landmarks for 5 days before and after surgery. Outcomes of interest were postoperative complications and adverse events measured using the Clavien-Dindo scale, treatment compliance, device usability according to the Systems Usability Scale (SUS) and clinical measures of bowel recovery. RESULTS: Forty patients were randomized and one withdrew, leaving 39 for analysis. Postoperative complications occurred in 9/19 (47.4%) participants receiving Sham and 11/20 (55.0%) receiving Active stimulation and were mostly minor. Compliance with treatment before surgery was 4.7 ± 0.9 days out of 5 days in the Sham group and 4.7 ± 1.1 in the Active group. Compliance with treatment after surgery was 4.1 ± 1.1 and 4.4 ± 1.5, respectively. Participants considered the intervention to be 'acceptable' according to the SUS. The most prominent differences in bowel recovery were days to first flatus (2.35 ± 1.32 vs 1.65 ± 0.88) and tolerance of solid diet (2.18 ± 2.21 vs 1.75 ± 0.91) for Sham and Active groups, respectively. CONCLUSION: This study supports the safety, treatment compliance and usability of self-administered nVNS in patients undergoing major colorectal surgery.

High hospital research participation and improved colorectal cancer survival outcomes: a population-based study.

OBJECTIVE: In 2001, the National Institute for Health Research Cancer Research Network (NCRN) was established, leading to a rapid increase in clinical research activity across the English NHS. Using colorectal cancer (CRC) as an example, we test the hypothesis that high, sustained hospital-level participation in interventional clinical trials improves outcomes for all patients with CRC managed in those research-intensive hospitals. DESIGN: Data for patients diagnosed with CRC in England in 2001-2008 (n=209 968) were linked with data on accrual to NCRN CRC studies (n=30 998). Hospital Trusts were categorised by the proportion of patients accrued to interventional studies annually. Multivariable models investigated the relationship between 30-day postoperative mortality and 5-year survival and the level and duration of study participation. RESULTS: Most of the Trusts achieving high participation were district general hospitals and the effects were not limited to cancer 'centres of excellence', although such centres do make substantial contributions. Patients treated in Trusts with high research participation (≥16%) in their year of diagnosis had lower postoperative mortality (p<0.001) and improved survival (p<0.001) after adjustment for casemix and hospital-level variables. The effects increased with sustained research participation, with a reduction in postoperative mortality of 1.5% (6.5%-5%, p<2.2×10-6) and an improvement in survival (p<10-19; 5-year difference: 3.8% (41.0%-44.8%)) comparing high participation for ≥4 years with 0 years. CONCLUSIONS: There is a strong independent association between survival and participation in interventional clinical studies for all patients with CRC treated in the hospital study participants. Improvement precedes and increases with the level and years of sustained participation.

A Cross-Sectional Review of Reporting Variation in Postoperative Bowel Dysfunction After Rectal Cancer Surgery.

BACKGROUND: Postoperative bowel dysfunction affects quality of life after sphincter-preserving rectal cancer surgery, but the extent of the problem is not clearly defined because of inconsistent outcome measures used to characterize the condition. OBJECTIVE: The purpose of this study was to assess variation in the reporting of postoperative bowel dysfunction and to make recommendations for standardization in future studies. If possible, a quantitative synthesis of bowel dysfunction symptoms was planned. DATA SOURCES: MEDLINE and EMBASE databases, as well as the Cochrane Library, were queried systematically between 2004 and 2015. STUDY SELECTION: The studies selected reported at least 1 component of bowel dysfunction after resection of rectal cancer. MAIN OUTCOME MEASURES: The main outcome measures were reporting, measurement, and definition of postoperative bowel dysfunction. RESULTS: Of 5428 studies identified, 234 met inclusion criteria. Widely reported components of bowel dysfunction were incontinence to stool (227/234 (97.0%)), frequency (168/234 (71.8%)), and incontinence to flatus (158/234 (67.5%)). Urgency and stool clustering were reported less commonly, with rates of 106 (45.3%) of 234 and 61 (26.1%) of 234. Bowel dysfunction measured as a primary outcome was associated with better reporting (OR = 3.49 (95% CI, 1.99-6.23); p < 0.001). Less than half of the outcomes were assessed using a dedicated research tool (337/720 (46.8%)), and the remaining descriptive measures were infrequently defined (56/383 (14.6%)). LIMITATIONS: Heterogeneity in the reporting, measurement, and definition of postoperative bowel dysfunction precluded pooling of results and limited interpretation. CONCLUSIONS: Considerable variation exists in the reporting, measurement, and definition of postoperative bowel dysfunction. These inconsistencies preclude reliable estimates of incidence and meta-analysis. A broadly accepted outcome measure may address this deficit in future studies.

Effect of Robotic-Assisted vs Conventional Laparoscopic Surgery on Risk of Conversion to Open Laparotomy Among Patients Undergoing Resection for Rectal Cancer: The ROLARR Randomized Clinical Trial.

Importance: Robotic rectal cancer surgery is gaining popularity, but limited data are available regarding safety and efficacy. Objective: To compare robotic-assisted vs conventional laparoscopic surgery for risk of conversion to open laparotomy among patients undergoing resection for rectal cancer. Design, Setting, and Participants: Randomized clinical trial comparing robotic-assisted vs conventional laparoscopic surgery among 471 patients with rectal adenocarcinoma suitable for curative resection conducted at 29 sites across 10 countries, including 40 surgeons. Recruitment of patients was from January 7, 2011, to September 30, 2014, follow-up was conducted at 30 days and 6 months, and final follow-up was on June 16, 2015. Interventions: Patients were randomized to robotic-assisted (n = 237) or conventional (n = 234) laparoscopic rectal cancer resection, performed by either high (upper rectum) or low (total rectum) anterior resection or abdominoperineal resection (rectum and perineum). Main Outcomes and Measures: The primary outcome was conversion to open laparotomy. Secondary end points included intraoperative and postoperative complications, circumferential resection margin positivity (CRM+) and other pathological outcomes, quality of life (36-Item Short Form Survey and 20-item Multidimensional Fatigue Inventory), bladder and sexual dysfunction (International Prostate Symptom Score, International Index of Erectile Function, and Female Sexual Function Index), and oncological outcomes. Results: Among 471 randomized patients (mean [SD] age, 64.9 [11.0] years; 320 [67.9%] men), 466 (98.9%) completed the study. The overall rate of conversion to open laparotomy was 10.1%: 19 of 236 patients (8.1%) in the robotic-assisted laparoscopic group and 28 of 230 patients (12.2%) in the conventional laparoscopic group (unadjusted risk difference = 4.1% [95% CI, -1.4% to 9.6%]; adjusted odds ratio = 0.61 [95% CI, 0.31 to 1.21]; P = .16). The overall CRM+ rate was 5.7%; CRM+ occurred in 14 (6.3%) of 224 patients in the conventional laparoscopic group and 12 (5.1%) of 235 patients in the robotic-assisted laparoscopic group (unadjusted risk difference = 1.1% [95% CI, -3.1% to 5.4%]; adjusted odds ratio = 0.78 [95% CI, 0.35 to 1.76]; P = .56). Of the other 8 reported prespecified secondary end points, including intraoperative complications, postoperative complications, plane of surgery, 30-day mortality, bladder dysfunction, and sexual dysfunction, none showed a statistically significant difference between groups. Conclusions and Relevance: Among patients with rectal adenocarcinoma suitable for curative resection, robotic-assisted laparoscopic surgery, as compared with conventional laparoscopic surgery, did not significantly reduce the risk of conversion to open laparotomy. These findings suggest that robotic-assisted laparoscopic surgery, when performed by surgeons with varying experience with robotic surgery, does not confer an advantage in rectal cancer resection. Trial Registration: isrctn.org Identifier: ISRCTN80500123.

SaFaRI: sacral nerve stimulation versus the FENIX magnetic sphincter augmentation for adult faecal incontinence: a randomised investigation.

PURPOSE: Faecal incontinence is a physically, psychologically and socially disabling condition. NICE guidance (2007) recommends surgical intervention, including sacral nerve stimulation (SNS), after failed conservative therapies. The FENIX magnetic sphincter augmentation (MSA) device is a novel continence device consisting of a flexible band of interlinked titanium beads with magnetic cores that is placed around the anal canal to augment anal sphincter tone through passive attraction of the beads. Preliminary studies suggest the FENIX MSA is safe, but efficacy data is limited. Rigorous evaluation is required prior to widespread adoption. METHOD AND DESIGN: The SaFaRI trial is a National Institute of Health Research (NIHR) Health Technology Assessment (HTA)-funded UK multi-site, parallel group, randomised controlled, unblinded trial that will investigate the use of the FENIX MSA, as compared to SNS, for adult faecal incontinence resistant to conservative management. Twenty sites across the UK, experienced in the treatment of faecal incontinence, will recruit 350 patients randomised equally to receive either SNS or FENIX MSA. Participants will be followed-up at 2 weeks post-surgery and at 6, 12 and 18 months post-randomisation. The primary endpoint is success, as defined by device in use and ≥50 % improvement in the Cleveland Clinic Incontinence Score (CCIS) at 18 months post-randomisation. Secondary endpoints include complications, quality of life and cost effectiveness. DISCUSSION: SaFaRI will rigorously evaluate a new technology for faecal incontinence, the FENIX™ MSA, allowing its safe and controlled introduction into current clinical practice. These results will inform the future surgical management of adult faecal incontinence.

Surgical trial design for incorporating the effects of learning: what is the current methodological guidance, and is it sufficient?

BACKGROUND: Surgical interventions are complex. Key elements of this complexity are the surgeon and their learning curve. They pose methodological challenges in the design, analysis and interpretation of surgical RCTs. We identify, summarise, and critically examine current guidance about how to incorporate learning curves in the design and analysis of RCTs in surgery. EXAMINING CURRENT GUIDANCE: Current guidance presumes that randomisation must be between levels of just one treatment component, and that the evaluation of comparative effectiveness will be made via the average treatment effect (ATE). It considers how learning effects affect the ATE, and suggests solutions which seek to define the target population such that the ATE is a meaningful quantity to guide practice. We argue that these are solutions to a flawed formulation of the problem, and are inadequate for policymaking in this setting. REFORMULATING THE PROBLEM: The premise that surgical RCTs are limited to single-component comparisons, evaluated via the ATE, has skewed the methodological discussion. Forcing a multi-component intervention, such as surgery, into the framework of the conventional RCT design ignores its factorial nature. We briefly discuss the multiphase optimisation strategy (MOST), which for a Stage 3 trial would endorse a factorial design. This would provide a wealth of information to inform nuanced policy but would likely be infeasible in this setting. We discuss in more depth the benefits of targeting the ATE conditional on operating surgeon experience (CATE). The value of estimating the CATE for exploring learning effects has been previously recognised, but with discussion limited to analysis methods only. The robustness and precision of such analyses can be ensured via the trial design, and we argue that trial designs targeting CATE represent a clear gap in current guidance. CONCLUSION: Trial designs that facilitate robust, precise estimation of the CATE would allow for more nuanced policymaking, leading to patient benefit. No such designs are currently forthcoming. Further research in trial design to facilitate the estimation of the CATE is needed.

Pathway Of Low Anterior Resection syndrome relief after Surgery (POLARiS) feasibility trial protocol: a multicentre, feasibility cohort study with embedded randomised control trial to compare sacral neuromodulation and transanal irrigation to optimised conservative management in the management of major low anterior resection syndrome following rectal cancer treatment.

INTRODUCTION: Rectal cancer is common with a 60% 5-year survival rate. Treatment usually involves surgery with or without neoadjuvant chemoradiotherapy or adjuvant chemotherapy. Sphincter saving curative treatment can result in debilitating changes to bowel function known as low anterior resection syndrome (LARS). There are currently no clear guidelines on the management of LARS with only limited evidence for different treatment modalities. METHODS AND ANALYSIS: Patients who have undergone an anterior resection for rectal cancer in the last 10 years will be approached for the study. The feasibility trial will take place in four centres with a 9-month recruitment window and 12 months follow-up period. The primary objective is to assess the feasibility of recruitment to the POLARiS trial which will be achieved through assessment of recruitment, retainment and follow-up rates as well as the prevalence of major LARS.Feasibility outcomes will be analysed descriptively through the estimation of proportions with confidence intervals. Longitudinal patient reported outcome measures will be analysed according to scoring manuals and presented descriptively with reporting graphically over time. ETHICS AND DISSEMINATION: Ethical approval has been granted by Wales REC1; Reference 22/WA/0025. The feasibility study is in the process of set up. The results of the feasibility trial will feed into the design of an expanded, international trial. TRIAL REGISTRATION NUMBER: CT05319054.

Sacral nerve stimulation versus the magnetic sphincter augmentation device for adult faecal incontinence: the SaFaRI RCT.

BACKGROUND: Preliminary studies using the FENIX™ (Torax Medical, Minneapolis, MN, USA) magnetic sphincter augmentation device suggest that it is safe to use for the treatment of adult faecal incontinence, but efficacy data are limited. OBJECTIVE: To compare FENIX with sacral nerve stimulation for the treatment of adult faecal incontinence in terms of safety, efficacy, quality of life and cost-effectiveness. DESIGN, SETTING AND PARTICIPANTS: Multicentre, parallel-group, unblinded, randomised trial comparing FENIX with sacral nerve stimulation in participants suffering moderate to severe faecal incontinence. INTERVENTIONS: Participants were randomised on an equal basis to either sacral nerve stimulation or FENIX. Follow-up occurred 2 weeks postoperatively and at 6, 12 and 18 months post randomisation. MAIN OUTCOME AND MEASURE: The primary outcome was success, defined as device in use and ≥ 50% improvement in Cleveland Clinic Incontinence Score at 18 months post randomisation. Secondary outcomes included complication rates, quality of life and cost-effectiveness. Between 30 October 2014 and 23 March 2017, 99 participants were randomised across 18 NHS sites (50 participants to FENIX vs. 49 participants to sacral nerve stimulation). The median time from randomisation to FENIX implantation was 57.0 days (range 4.0-416.0 days), and the median time from randomisation to permanent sacral nerve stimulation was 371.0 days (range 86.0-918.0 days). A total of 45 out of 50 participants underwent FENIX implantation and 29 out of 49 participants continued to permanent sacral nerve stimulation. The following results are reported, excluding participants for whom the corresponding outcome was not evaluable. Overall, there was success for 10 out of 80 (12.5%) participants, with no statistically significant difference between the two groups [FENIX 6/41 (14.6%) participants vs. sacral nerve stimulation 4/39 (10.3%) participants]. At least one postoperative complication was experienced by 33 out of 45 (73.3%) participants in the FENIX group and 9 out of 40 (22.5%) participants in the sacral nerve stimulation group. A total of 15 out of 50 (30%) participants in the FENIX group ultimately had to have their device explanted. Slightly higher costs and quality-adjusted life-years (incremental = £305.50 and 0.005, respectively) were observed in the FENIX group than in the sacral nerve stimulation group. This was reversed over the lifetime horizon (incremental = -£1306 and -0.23 for costs and quality-adjusted life-years, respectively), when sacral nerve stimulation was the optimal option (net monetary benefit = -£3283), with only a 45% chance of FENIX being cost-effective. LIMITATIONS: The SaFaRI study was terminated in 2017, having recruited 99 participants of the target sample size of 350 participants. The study is, therefore, substantially underpowered to detect differences between the treatment groups, with significant uncertainty in the cost-effectiveness analysis. CONCLUSIONS: The SaFaRI study revealed inefficiencies in the treatment pathways for faecal incontinence, particularly for sacral nerve stimulation. The success of both FENIX and sacral nerve stimulation was much lower than previously reported, with high postoperative morbidity in the FENIX group. FUTURE WORK: Further research is needed to clarify the treatment pathways for sacral nerve stimulation and to determine its true clinical and cost-effectiveness. TRIAL REGISTRATION: Current Controlled Trials ISRCTN16077538. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 18. See the NIHR Journals Library website for further project information.

Faecal incontinence is a distressing condition for patients, and surgery is recommended if symptoms are having an effect on quality of life. One of the treatments recommended for faecal incontinence by the National Institute for Health and Care Excellence is sacral nerve stimulation, which aims to improve continence by stimulating the nerves to the back passage. A newer treatment involves surgery to implant a string of magnetic beads around the anal canal using the FENIX™ device (Torax Medical, Minneapolis, MN, USA). The aim of this study was to assess the benefits and risks of the FENIX device compared with sacral nerve stimulation. The SaFaRI study aimed to recruit 350 participants with faecal incontinence, but was stopped early because of the manufacturer withdrawing the FENIX device for strategic reasons. In total, we recruited 99 participants. Fifty participants were allocated to receive the FENIX device and 49 participants were allocated to receive sacral nerve stimulation. The observed success rates with both devices were low: at 18 months following their entry into the study, 6 out of 41 (14.6%) participants in the FENIX group and 4 out of 39 (10.3%) participants in the sacral nerve stimulation group had the device both in use and producing a benefit. A total of 5 out of 50 (10.0%) participants allocated to receive the FENIX device did not have a device implanted, and 15 out of 45 (33.3%) participants who did have the FENIX device implanted needed to have it removed because of complications during the 18-month follow-up period. A total of 21 out of 49 (42.9%) participants allocated to receive sacral nerve stimulation did not have a permanent sacral nerve stimulation device implanted, and 0 of the 28 who did have a permanent sacral nerve stimulation device implanted needed to have it removed during the 18-month follow-up period. The costs associated with the FENIX device were higher because of a greater number of participants experiencing complications, meaning that the FENIX device is unlikely to be cost-effective in the treatment of faecal incontinence compared with sacral nerve stimulation.

Liver resection surgery compared with thermal ablation in high surgical risk patients with colorectal liver metastases: the LAVA international RCT.

BACKGROUND: Although surgical resection has been considered the only curative option for colorectal liver metastases, thermal ablation has recently been suggested as an alternative curative treatment. There have been no adequately powered trials comparing surgery with thermal ablation. OBJECTIVES: Main objective - to compare the clinical effectiveness and cost-effectiveness of thermal ablation versus liver resection surgery in high surgical risk patients who would be eligible for liver resection. Pilot study objectives - to assess the feasibility of recruitment (through qualitative study), to assess the quality of ablations and liver resection surgery to determine acceptable standards for the main trial and to centrally review the reporting of computed tomography scan findings relating to ablation and outcomes and recurrence rate in both arms. DESIGN: A prospective, international (UK and the Netherlands), multicentre, open, pragmatic, parallel-group, randomised controlled non-inferiority trial with a 1-year internal pilot study. SETTING: Tertiary liver, pancreatic and gallbladder (hepatopancreatobiliary) centres in the UK and the Netherlands. PARTICIPANTS: Adults with a specialist multidisciplinary team diagnosis of colorectal liver metastases who are at high surgical risk because of their age, comorbidities or tumour burden and who would be suitable for liver resection or thermal ablation. INTERVENTIONS: Thermal ablation conducted as per local policy (but centres were encouraged to recruit within Cardiovascular and Interventional Radiological Society of Europe guidelines) versus surgical liver resection performed as per centre protocol. MAIN OUTCOME MEASURES: Pilot study - patients' and clinicians' acceptability of the trial to assist in optimisation of recruitment. Primary outcome - disease-free survival at 2 years post randomisation. Secondary outcomes - overall survival, timing and site of recurrence, additional therapy after treatment failure, quality of life, complications, length of hospital stay, costs, trial acceptability, and disease-free survival measured from end of intervention. It was planned that 5-year survival data would be documented through record linkage. Randomisation was performed by minimisation incorporating a random element, and this was a non-blinded study. RESULTS: In the pilot study over 1 year, a total of 366 patients with colorectal liver metastases were screened and 59 were considered eligible. Only nine participants were randomised. The trial was stopped early and none of the planned statistical analyses was performed. The key issues inhibiting recruitment included fewer than anticipated patients eligible for both treatments, misconceptions about the eligibility criteria for the trial, surgeons' preference for one of the treatments ('lack of clinical equipoise' among some of the surgeons in the centre) with unconscious bias towards surgery, patients' preference for one of the treatments, and lack of dedicated research nurses for the trial. CONCLUSIONS: Recruitment feasibility was not demonstrated during the pilot stage of the trial; therefore, the trial closed early. In future, comparisons involving two very different treatments may benefit from an initial feasibility study or a longer period of internal pilot study to resolve these difficulties. Sufficient time should be allowed to set up arrangements through National Institute for Health Research (NIHR) Research Networks. TRIAL REGISTRATION: Current Controlled Trials ISRCTN52040363. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 21. See the NIHR Journals Library website for further project information.

In about 50% of people with bowel cancer, cancer spreads to the liver (colorectal liver metastases) within 5 years of detection and treatment. Liver resection (i.e. surgical removal of a portion of the liver) is the standard treatment in people below 70 years of age who are otherwise well, provided that the liver cancer is confined to a limited part of the liver. Such patients are considered 'low-risk' patients. Older patients and those with major medical problems or extensive cancers are considered 'high-risk' patients, as they are at a higher risk of developing complications following liver resection. Thermal ablation destroys the liver cancers using a needle that heats the cancer deposits until they are destroyed. There is significant uncertainty as to whether or not ablation can offer equivalent survival compared with surgery for 'high-risk' patients. We planned and conducted a randomised controlled trial comparing ablation with surgery to resolve this uncertainty. In this trial, some patients received ablation and others received surgery. The treatment was allocated at random with neither patients nor the study organisers choosing the treatment. The trial had an internal pilot (i.e. a smaller version of the full trial to resolve any 'teething problems' and ensure that a sufficient number of participants can be included in the full trial). Only nine patients were recruited in the 1-year internal pilot, compared with the anticipated recruitment of 45 patients. Therefore, the trial closed early as a result of poor recruitment, and the uncertainty about the best treatment for high-risk patients with colorectal liver metastases continues. The main reasons for the poor recruitment included fewer than anticipated eligible participants, clinicians' unconscious bias towards surgery, and patients' preference for one treatment or the other. In the future, comparisons involving two very different treatments may benefit from a feasibility study or a longer period of pilot study to resolve any difficulties.

Exploring and adjusting for potential learning effects in ROLARR: a randomised controlled trial comparing robotic-assisted vs. standard laparoscopic surgery for rectal cancer resection.

BACKGROUND: Commonly in surgical randomised controlled trials (RCT) the experimental treatment is a relatively new technique which the surgeons may still be learning, while the control is a well-established standard. This can lead to biased comparisons between treatments. In this paper we discuss the implementation of approaches for addressing this issue in the ROLARR trial, and points of consideration for future surgical trials. METHODS: ROLARR was an international, randomised, parallel-group trial comparing robotic vs. laparoscopic surgery for the curative treatment of rectal cancer. The primary endpoint was conversion to open surgery (binary). A surgeon inclusion criterion mandating a minimum level of experience in each technique was incorporated. Additionally, surgeon self-reported data were collected periodically throughout the trial to capture the level of experience of every participating surgeon. Multi-level logistic regression adjusting for operating surgeon as a random effect is used to estimate the odds ratio for conversion to open surgery between the treatment groups. We present and contrast the results from the primary analysis, which did not account for learning effects, and a sensitivity analysis which did. RESULTS: The primary analysis yields an estimated odds ratio (robotic/laparoscopic) of 0.614 (95% CI 0.311, 1.211; p = 0.16), providing insufficient evidence to conclude superiority of robotic surgery compared to laparoscopic in terms of the risk of conversion to open. The sensitivity analysis reveals that while participating surgeons in ROLARR were expert at laparoscopic surgery, some, if not all, were still learning robotic surgery. The treatment-effect odds ratio decreases by a factor of 0.341 (95% CI 0.121, 0.960; p = 0.042) per unit increase in log-number of previous robotic operations performed by the operating surgeon. The odds ratio for a patient whose operating surgeon has the mean experience level in ROLARR - 152.46 previous laparoscopic, 67.93 previous robotic operations - is 0.40 (95% CI 0.168, 0.953; p = 0.039). CONCLUSIONS: In this paper we have demonstrated the implementation of approaches for accounting for learning in a practical example of a surgery RCT analysis. The results demonstrate the value of implementing such approaches, since we have shown that without them the ROLARR analysis would indeed have been confounded by the learning effects. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number (ISRCTN) registry, ID: ISRCTN80500123. Registered on 27 May 2010.

Liver resection surgery versus thermal ablation for colorectal LiVer MetAstases (LAVA): study protocol for a randomised controlled trial.

BACKGROUND: Although surgical resection has been considered the only curative option for colorectal liver metastases (CLM), thermal ablation has recently been suggested as an alternative curative treatment. A prospective randomised trial is required to define the efficacy of resection vs ablation for the treatment of colorectal liver metastases. METHODS: Design and setting: This is a multicentre, open, randomised controlled non-inferiority trial design with internal pilot and will be performed in tertiary liver centres in UK and The Netherlands. PARTICIPANTS: Eligible patients will be those with colorectal liver metastases at high surgical risk because of their age, co-morbidities or tumour burden and who would be suitable for liver resection or thermal ablation. INTERVENTION: Thermal ablation as per local policy. CONTROL: Surgical liver resection performed as per centre protocol. Co-interventions: Further chemotherapy will be offered to patients as per current practice. Outcomes Pilot study: Same as main study and in addition patients and clinicians' acceptability of the trial to assist in optimisation of recruitment. PRIMARY OUTCOME: Disease-free survival (DFS) at two years post randomisation. SECONDARY OUTCOMES: Overall survival, timing and site of recurrence, additional therapy after treatment failure, quality of life, complications, length of hospital stay, costs, trial acceptability, DFS measured from end of intervention. FOLLOW-UP: 24 months from randomisation; five-year follow-up for overall survival. SAMPLE SIZE: 330 patients to demonstrate non-inferiority of thermal ablation. DISCUSSION: This trial will determine the effectiveness and cost-effectiveness of thermal ablation vs surgical resection for high-risk people with colorectal liver metastases, and guide the optimal treatment for these patients. TRIAL REGISTRATION: ISRCTN Registry, ISRCTN52040363 . Registered on 9 March 2016.

Changing cluster composition in cluster randomised controlled trials: design and analysis considerations.

BACKGROUND: There are many methodological challenges in the conduct and analysis of cluster randomised controlled trials, but one that has received little attention is that of post-randomisation changes to cluster composition. To illustrate this, we focus on the issue of cluster merging, considering the impact on the design, analysis and interpretation of trial outcomes. METHODS: We explored the effects of merging clusters on study power using standard methods of power calculation. We assessed the potential impacts on study findings of both homogeneous cluster merges (involving clusters randomised to the same arm of a trial) and heterogeneous merges (involving clusters randomised to different arms of a trial) by simulation. To determine the impact on bias and precision of treatment effect estimates, we applied standard methods of analysis to different populations under analysis. RESULTS: Cluster merging produced a systematic reduction in study power. This effect depended on the number of merges and was most pronounced when variability in cluster size was at its greatest. Simulations demonstrate that the impact on analysis was minimal when cluster merges were homogeneous, with impact on study power being balanced by a change in observed intracluster correlation coefficient (ICC). We found a decrease in study power when cluster merges were heterogeneous, and the estimate of treatment effect was attenuated. CONCLUSIONS: Examples of cluster merges found in previously published reports of cluster randomised trials were typically homogeneous rather than heterogeneous. Simulations demonstrated that trial findings in such cases would be unbiased. However, simulations also showed that any heterogeneous cluster merges would introduce bias that would be hard to quantify, as well as having negative impacts on the precision of estimates obtained. Further methodological development is warranted to better determine how to analyse such trials appropriately. Interim recommendations include avoidance of cluster merges where possible, discontinuation of clusters following heterogeneous merges, allowance for potential loss of clusters and additional variability in cluster size in the original sample size calculation, and use of appropriate ICC estimates that reflect cluster size.