Background
Review
Designing surgical interventions within RCTs
Description | |
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1 | Does the RCT involve a surgical intervention? |
2 | What is/are the surgical intervention(s) under evaluation? |
3 | What is/are the concomitant intervention(s) accompanying surgery? |
4 | What will influence standardisation of the interventions? |
a. What is the overall study design? | |
b. What type of comparator is in the RCT? | |
c. In what stage of development is/are the surgical intervention(s)? | |
5 | How will the intervention(s) be standardised in the RCT? |
6 | How will delivery of the intervention(s) be monitored in the RCT (fidelity)? |
7 | Who will deliver the intervention(s) (operator expertise)? |
8 | Where will the intervention(s) be delivered (context)? |
Term | Definition |
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Complex intervention | An intervention with multiple components that act inter-dependently or independently to influence outcomes [6]. |
Surgical intervention | An intervention that cuts or physically alters a patient’s tissues (whether using a scalpel, stapler, laser or another instrument or device) and involves the use of a sterile environment, anaesthesia, antiseptic conditions and suturing or stapling [10]. |
Concomitant intervention (or co-intervention) | Interventions that naturally accompany or are associated with the intervention itself [22]. Concomitant interventions can occur before, during or after the main intervention. |
Context | The distinctive features of an intervention’s setting, participants and delivery [23]. |
Expertise | The ability to integrate technical and non-technical skills to complete challenging tasks. |
Fidelity | How far those responsible for delivering an intervention actually adhere to the intervention as it is outlined by its designers [24]. Fidelity is also referred to as compliance or adherence. |
Pragmatic trial | A trial which is designed to answer the question ‘How well does the intervention work in comparison to the control when delivered under usual conditions?’ [25] (that is, effectiveness focused, usually aiming to influence health policy) |
Explanatory trial | A trial that is designed to answer the question ‘How well does the intervention work in comparison to the control when delivered under ideal conditions?’ [25] (that is, efficacy focused, usually aiming to investigate the causal relationship between an intervention and physiological processes) |
Does the RCT involve at least one surgical intervention?
What are the surgical interventions under evaluation?
Components | Definition | Description | Steps within each component |
---|---|---|---|
Two further 0.5-cm incisions in the left iliac fossa and suprapubic regions. | |||
Separation and incision of the fat, fascia, muscular layers and peritoneum. | Identification of the base of the umbilicus. | ||
Incision of fascia using a knife and peritoneum using scissors. | |||
Creation of a pneumoperitoneum | Insertion of the laparoscopic ports (through fascia and peritoneum). | ||
Insufflation of gas into the abdomen. | |||
Dissection of the appendix | The process of exposing an organ, tissue or structure | Dissection of tissues surrounding the appendix. | Use of a laparoscopic hook and diathermy to dissect the appendix from surrounding tissues. |
Isolation and ligation of the blood supply. | Use of hook diathermy to divide the mesoappendix and coagulate the artery. | ||
Resection of the appendix | Removal of all or part of an organ, tissue, or structure | Securing the appendix base with staples/sutures. | Application of sutures to the base of the appendix. |
Division of the base of the appendix. | Cutting of the appendix from its base with laparoscopic scissors. | ||
Removal of the appendix from theabdomen. | Placement of a bag into the abdomen within which to retrieve the appendix through a laparoscopic port. | ||
Closure of the abdomen | Closure of the abdominal layers | Closure of the peritoneum, fascia and skin. | Closure of the fascia at the umbilical port site using a box stitch. Closure of the skin at all three port sites, using sutures or steri-strips. |
What are the concomitant interventions accompanying the surgical intervention?
Pre-, peri- or post-operative | Concomitant interventions | Description |
---|---|---|
Pre-operative | Magnetic resonance imaging | Pre-operative imaging to plan the exact type of implant required |
Investigations within the pre-operative assessment clinic | Pre-operative blood tests, electrocardiogram, X-rays and other interventions (such as echocardiogram) as required | |
Physiotherapy | Muscle strengthening exercises | |
Peri-operative | Application of pulse oximeter, oxygen mask and blood pressure cuff | Intra-operative monitoring devices |
Application of continuous pump devices and compression stockings | Preventative measures for deep vein thrombosis | |
Insertion of a urinary catheter | To prevent urinary retention (potential consequence of spinal anaesthesia) | |
Insertion of a peripheral cannula | To allow delivery of intravenous analgesia | |
Administration of spinal anaesthesia | Injection of a local anaesthetic into the subarachnoid space, through a fine needle | |
Administration of intravenous analgesia | To minimise intra-operative pain | |
Application of a knee bandage | To provide pressure and minimise swelling | |
Post-operative | Administration of subcutaneous clexane | Preventative measures for deep vein thrombosis |
Application of continuous pump devices and compression stockings | Preventative measures for deep vein thrombosis | |
Administration of oral analgesia | To minimise post-operative pain | |
Physiotherapy | Muscle strengthening exercises and learning to walk with crutches or a frame | |
Use of a continuous passive movement machine | Provide passive motion in a specific plane of movement, and protect the healing repair or tissue |
What will influence the amount of standardisation needed for the intervention?
Factors contributing to the level of control required | Example of RCTs requiring less standardisation | Example of RCTs requiring more standardisation |
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Scope of the trial | Comparison of surgery and medical therapy for treatment of gastro-oesophageal reflux disease [26] | Carotid artery stenting compared with endarterectomy in patients with carotid stenosis [27] |
Pragmatic versus explanatory approach to design | Pragmatic: The trial aimed to establish the effectiveness of the interventions in practice | Explanatory: The trial aimed to establish the safety and efficacy of the ‘new’ intervention (stenting) under ideal conditions |
Stage of innovation of the intervention | Open versus minimally invasive surgery for colorectal cancer [28] | Endovascular versus open repair of abdominal aortic aneurysms [29] |
Established versus new innovation | Established: Open colorectal surgery is routinely undertaken by many operators in clinical practice and the main steps are already known | Early: Endovascular aneurysm repair is a relatively new technique and the main steps are less well known |
Complexity of the intervention | Effect of an implantable gentamicin-collagen sponge on sternal wound infections following cardiac surgery [30] | Extracranial-intracranial bypass surgery for stroke prevention in hemodynamic cerebral ischemia [31] |
Few components and low technical difficulty versus multiple components or requiring highly complex skills | Low complexity: Intervention involves placing an antibiotic impregnated sponge beneath patients’ wounds prior to closure | High complexity: Intervention is complex involving multiple components, high levels of technical expertise and multiple concomitant interventions |
Nature of interventions being compared | Amoxicillin plus clavulanic acid versus appendicectomy for treatment of acute uncomplicated appendicitis [32] | Laparoscopic gastric bypass versus laparoscopic duodenal switch for super obesity [33] |
Surgical and non-surgical intervention, or different surgical interventions | Surgery versus non-surgery: Distinction between trial groups is straightforward because of the very different nature of interventions | Surgery versus surgery: Distinction between the two groups is less straightforward because both interventions are surgical |
What is the overall trial design?
What type of comparator is in the study?
What stage of development is the intervention?
How will the intervention(s) be standardised in the RCT?
Trial features | |
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Journal, year of publication | Lancet, 2009 |
Aim of RCT | To compare survival between standard or minimally invasive surgery in patients with colorectal cancer [28]. |
Main findings | The survival rate following minimally invasive surgery was non-inferior to standard surgery |
Verbatim description of the surgical intervention | The following description was provided for both open and minimally invasive surgery: ‘Resection involved the division of blood vessels and bowel’. Conversion to open surgery was defined as a ‘vertical incision’. No other description regarding the incisions was provided. |
Published correspondence | ‘What about right-sided cancers? It is well known among laparoscopic surgeons that ‘laparoscopic’ right colectomy can in fact mean three different kinds of procedures: a true or totally laparoscopic right colectomy (with both dissection and anastomosis done intra-corporeally), laparoscopically assisted colectomy (with only the vascular ligation done intra-corporeally), or so-called laparoscopic colectomy (with only the colonic dissection done laparoscopically). The authors of the CLASICC trial stated only that resection involved ‘(where possible) the division of blood vessels and bowel’. Conversion was defined as a ‘vertical incision’, but what about (for example) a transverse incision of almost 7 cm in a thin patient allowing both division of vessels and bowel after a simple laparoscopic colonic mobilisation? Is that procedure laparoscopic or open? Since the actual procedure is not specified, the external validity of trials regarding the laparoscopic approach for right-sided colon cancers should be questioned [34].’ |
Will intervention delivery be monitored during the trial? If so, how?
Who will deliver the interventions?
Where will the interventions be delivered?
Discussion
Conclusions
Acknowledgements
Simon Bach1 | s.p.bach@bham.ac.uk |
David Beard2 | david.beard@ndorms.ox.ac.uk |
Marion K Campbell3 | m.k.campbell@abdn.ac.uk |
Andrew Carr2 | andrew.carr@ndorms.ox.ac.uk |
Elizabeth J Conroy4 | e.j.conroy@liverpool.ac.uk |
Matthew Costa5 | matthew.costa@warwick.ac.uk |
Peter Davidson6 | hta@hta.ac.uk |
Jenny Donovan7 | jenny.donovan@bristol.ac.uk |
Caroline J Doré8 | c.dore@ctu.mrc.ac.uk |
Trish Groves9 | tgroves@bmj.com |
Iain Hutchison10 | hutch.london@googlemail.com |
Abhilash Jain2 | ajainuk@aol.com |
David Jayne11 | d.g.jayne@leeds.ac.uk |
Angelos G Kolias12 | angeloskolias@gmail.com |
Sallie Lamb5 | s.lamb@warwick.ac.uk |
James McCaul13 | jim.mccaul@mac.com |
Hisham Mehanna1 | h.mehanna@bham.ac.uk |
Alan A Montgomery14 | alan.montgomery@nottingham.ac.uk |
Thomas Pinkney1 | thomas.pinkney@uhb.nhs.uk |
Shelley Potter8 | shelley.potter@bristol.ac.uk |
Amar Rangan15 | amar.rangan@durham.ac.uk |
Chris Rogers8 | chris.rogers@bristol.ac.uk |
Peter Sasieni10 | p.sasieni@qmul.ac.uk |
Sally Stenning8 | s.stenning@ctu.mrc.ac.uk |
Catrin Tudur Smith5 | cat1@liverpool.ac.uk |
Ian White16 | ian.white@mrc-bsu.cam.ac.uk |
Brian Williams17 | brian.williams@stir.ac.uk |
Paula R Williamson5 | p.r.williamson@liverpool.ac.uk |