The ORION Trial

RadiO fRequency ablatION for haemorrhoids (ORION). A Pragmatic multicentre patient-/assessor-blind parallel-group individual participant randomised (1:1 allocation) randomised controlled trial.


ORION Trial updates

The ORION Trial opened for recruitment in January 2022. As of 16 March 2023, we have recruited 156 people from 13 NHS Trusts across the UK, and we're still open to recruitment for new sites and participants.

Lots of our patients have now reached the six-week post-surgery follow-up visit and a few are approaching the one-year follow-up!

Keep an eye on our Twitter for the latest updates


Haemorrhoids are common, affecting as many as 1 in 3 of the population, and can cause symptoms including discomfort and bleeding, and are a common reason for review in a surgical clinic. Over 20,000 operations are carried out each year in England alone. Repeated visits to health care services as well as prolonged recovery after some interventions represents a significant disruption to the personal and working lives of a large proportion of the population. 

Interventions, for those whose symptoms remain after trying conservative management in the form of diet and habit modification, are influenced mainly by the degree of prolapse. These interventions range from rubber band ligation (RBL), which appears safe, and is easy to carry out, to haemorrhoidal artery ligation, stapled haemorrhoidopexy or haemorrhoidectomy. All interventions are available on the NHS. 

An alternative procedure to treat haemorrhoids is the use of radiofrequency ablation (RFA). RFA is primarily intended for use in patients whose haemorrhoid has failed to respond to less invasive outpatient procedures such as RBL as well as an alternative to operative procedures for those with a higher degree of prolapse where office procedures are likely to be ineffective. RFA is available to the NHS through the Rafaelo® device and has many potential advantages over the other surgical interventions and is therefore increasing in popularity. As the intervention does not excise tissue or generate excessive heat it should result in minimal discomfort and has been suggested to be faster than excisional treatments with a more rapid recovery. The evidence base for these claims is however limited, mainly from small cohort studies in specialist settings. More importantly, the promising longer-term efficacy has not been subject to a randomised comparison.

The ORION trial

RFA has not been tested enough for us to be sure it is as good as some suggest, and the cost is higher than that of other interventions. The aim of the ORION trial is to assess whether RFA is as efficacious as existing methods of treating haemorrhoids and if it is also superior in terms of pain and recurrence. 

ORION will be a full-scale trial that compares RFA’s effectiveness with the surgeon’s choice of surgery for patients whose haemorrhoids are severe enough to warrant surgery. The control arm of the trial will be the surgeon’s choice of any of the three most used surgeries – haemorrhoidal artery ligation, stapled haemorrhoidopexy or haemorrhoidectomy – and the intervention arm will be surgery using RFA. Patients will be randomised to either arm. 

View the ORION trial website

Central study staff

Name Title Organisation Email
Steven Brown Chief Investigator Sheffield Teaching Hospitals NHS Foundation Trust
Daniel Hind Trial Oversight  University of Sheffield
Carla Girling Study Manager University of Sheffield
Annie Little Trials Support Officer University of Sheffield
Katie Risdale Research Assistant University of Sheffield
Noa Haynes Research Assistant University of Sheffield


David Jayne


University of Leeds

Dale Vimalchandran

RCS Subspeciality Lead Colorectal Surgery

Countess of Chester Hospital NHS Foundation Trust

Daniel Hind

Assistant Director

Sheffield CTRU, ScHARR, The University of Sheffield

Matthew Lee

NIHR Clinical Lecturer

The University of Sheffield

Mike Bradburn

Senior Statistician 

Sheffield CTRU, ScHARR, The University of Sheffield

Shaun Stancliffe 

Patient Representative



This project is funded by the National Institute for Health Research, Health Technology Assessment (NIHR HTA) Programme (Ref NIHR131861).

ORION trial sites

Site name


Sheffield Teaching Hospital NHS Foundation Trust


Barking Havering and Redbridge University Hospitals NHS Trust


Mid & South Essex NHS Foundation Trust


University College London Hospital NHS Foundation Trust


University Hospitals Birmingham NHS Foundation Trust


Liverpool University Hospitals NHS Foundation Trust


Cardiff & Vale University Health Board


Dartford & Gravesham NHS Trust


Kings College Hospital NHS Foundation Trust


East Lancashire Hospital NHS Trust


Northumbria Healthcare NHS Foundation Trust


University Hospitals Dorset NHS Foundation Trust


Royal Bolton Hospital NHS Foundation Trust


Torbay and South Devon NHS Foundation Trust


Chelsea and Westminster Hospital NHS Foundation Trust (West Middlesex)


Wrightington, Wigan and Leigh Teaching Hospitals NHS Foundation Trust


Countess of Chester NHS Foundation Trust Open
St Helens and Knowsley Teaching Hospitals NHS Foundation Trust Open


Access the ORION trial protocol

Centres of excellence

The University's cross-faculty research centres harness our interdisciplinary expertise to solve the world's most pressing challenges.