The validation and application of a novel colonic polypectomy trainer

343 Pages·2014·13.56 MB·English

by  Mr. James Ansell

Doctor of Medicine (MD)

The validation and application of a novel
colonic polypectomy trainer

The WIMAT colonoscopy suitcase

By

James Ansell
March 2014
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Summary
Background and Aims
The WIMAT colonoscopy suitcase is an ex-vivo, porcine, polypectomy simulator. This has
been developed in response to the increasing demand for polypectomy training following the
introduction of the National Bowel Cancer Screening Programme. The aims of this thesis are
to establish if the simulator is a valid form of polypectomy skills training and to identify if
this model can be used to develop objective parameters for polypectomy assessment.
Materials and Methods
A series of clinical trials were systematically conducted to test the validity of the WIMAT
colonoscopy suitcase. This included evaluating its content, construct and concurrent validity
and conducting a skills transfer study comparing the WIMAT colonoscopy suitcase with a
virtual reality simulator. Objective assessment parameters were examined by measuring the
accuracy of self-assessment and using video coding software to analyse the hand movements
performed during simulated polypectomy tasks.
Results
Content validity was demonstrated by experts who scored the model’s anatomical,
mechanical and visual realism favourably across multiple parameters (p=<0.01). Construct
and concurrent validity were confirmed by participants performing simulated polypectomy in
accordance with their “real-life” level of expertise (p=<0.01). Skills transfer to the clinical
setting was demonstrated in a pilot randomised controlled study. Self-assessment following
simulated polypectomy is inaccurate as experts tend to overestimate ability whereas novices
underestimate ability (p=>0.05). The ratio of rotational hand movements to endoscopic tip
angulation (RoTA) was significantly different when comparing novices to experts (p=<0.05).
Discussion
The WIMAT colonoscopy suitcase is a valid form of polypectomy skills training. The
simulator can be used to address the increasing demand for training in this procedure. Further
work is needed to assess the reliability of the RoTA score at different stages of the
polypectomy procedure before it is used as an assessment tool.

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DECLARATION
This work has not previously been accepted in substance for any degree and is not
concurrently submitted in candidature for any degree.
Signed ………………………………………… (candidate) Date: 21/07/2014
STATEMENT 1
This thesis is being submitted in partial fulfilment of the requirements for the degree of MD
Signed ………………………………………… (candidate) Date: 21/07/2014
STATEMENT 2
This thesis is the result of my own independent work/investigation, except where otherwise
stated. Other sources are acknowledged by explicit references.
Signed …………………………………………(candidate) Date: 21/07/2014
STATEMENT 3
I hereby give consent for my thesis, if accepted, to be available for photocopying and for
inter-library loan, and for the title and summary to be made available to outside organisations.
Signed ………………………………………… (candidate) Date: 21/07/2014
STATEMENT 4
I hereby give consent for my thesis, if accepted, to be available for photocopying and for
inter-library loans after expiry of a bar on access previously approved by the Graduate
Development Committee.
Signed…………………………………………(candidate) Date: 21/07/2014
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Form: PGR_Submission_200701

NOTICE OF SUBMISSION OF THESIS FORM:
POSTGRADUATE RESEARCH
NOTICE OF SUBMISSION OF THESIS: POSTGRADUATE RESEARCH DEGREES
CANDIDATE’S LAST NAME ANSELL
CANDIDATE’S FIRST NAME(S) JAMES
CANDIDATE’S ID NUMBER M20003097
SCHOOL MEDICINE
Please circle appropriate degree title
TITLE OF DEGREE EdD, EngD, DSW, DClinPsy, DHS, MCh, MD, MPhil, MScD by
Research, PhD
THE VALIDATION AND APPLICATION OF A
FULL TITLE OF THESIS NOVEL COLONIC POLYPECTOMY TRAINER:
THE WIMAT COLONOSCOPY SUITCASE
IS THIS A RESUBMISSION? NO
THESIS SUBMITTED FOR Permanent Binding
EXAMINATION IN Temporary binding

FULL ADDRESS FOR RECEIPT OF 6 Thornwood Close,
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C ANDIDATE SIGNATURE DATE 21/07/2014
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Acknowledgements

Many people have contributed to the work described in this thesis and their support is
gratefully received. Firstly, I would like to express my gratitude to my principal supervisor,
Mr Jared Torkington for his full support, expert advice and encouragement over the last two
years. I would also like to thank my academic supervisors, Dr Neil Warren and Professor
Keith Harding who have been invaluable in generating ideas, appraising work and guiding
me through the development of this research. I am also grateful to Professor Patricia Price
who kindly shared her time to advise on the statistical analysis of these results. I would also
like to thank Mr Konstantinos Arnaoutakis and Mr Stuart Goddard for their methodological
advice and technical support. Drs James Horwood, Joanna Hurley, Raji Ramaraj and Medical
Students’ Chantelle Rizan and James Glasbey all assisted with data collection. Their
contributions are all grateful acknowledged.

This work has been funded by a generous grant from the Royal College of Surgeons of
England Research Fellowship. I am very appreciative of Mr Martyn Coomer and his team for
their help and support. I would especially like to thank Mr Brian Rees who has been a valued
role model and mentor to me throughout my surgical career.

Finally, I would like to thank my wife, Tania and my family for their unconditional love and
support during the last two years. I would not have been able to complete this thesis without
their continuous encouragement.
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List of abbreviations

A Advanced
AD Advanced skills in colonoscopy
ABP Animal By-Products
BA Basic Skills in Colonoscopy
BE Bench Model
CAE Canadian Aviation Electronics
CI Confidence Interval
CO Cohort
CONSORT Consolidated Standards Of Reporting Trials

DOPS Directly Observed Procedural Skills
DOPyS Direct Observation of Polypectomy Skills
E Expert
EGT Eye Gaze Technology
ERIC Education Resources Information Centre
EMR Endoscopic Mucosal Resection
ESD Endoscopic Submucosal Dissection
EV Ex-vivo
EUS Endoscopic Ultrasound
FOB Faecal Occult Blood
FN Foundation Skills
GI Gastro Intestinal
I Intermediate
ICF Informed Consent Form
ID Identification
IN Intermediate skills in colonoscopy
IQR Inter-Quartile Range
IRGUS Image Registered Gastroscopic Ultrasound System
ISRCTN International Standard Randomised Controlled Trial Number
JAG Joint Advisory Group on Gastro Intestinal Endoscopy
JETS JAG Endoscopy Training System
LA Live Animal
MeSH Medical Subject Headings
MINS Minutes
MOD Module
N Novice
NBCSP National Bowel Cancer Screening Programme
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NHS National Health Service
NOTES Natural Orifice Transluminal Endoscopic Surgery
OGD Oesophago-Gastro-Duodenoscopy
PASW Predictive Analytics SoftWare
PDP Personal Development Plan
PEG Percutaneously Endoscopic Gastroscopy
PRISMA Preferred Reporting Items for Systematic Review and Meta-Analyses
PY Polypectomy training course
RAF-c Rotterdam Assessment Form for colonoscopy
RCT Randomised Controlled Trial
REC Research Ethics Committee
RoTA Rotation To Angulation
SE Standard Error
SPSS Statistical Package for the Social Sciences
ST Specialty Trainee
TEM Transanal Endoscopic Microsurgery
TEO Transanal Endoscopic Operation
VGP Visual Gaze Pattern
VR Virtual Reality
WIMAT Welsh Institute for Minimal Access Therapy

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“Better is possible. It does not take genius. It takes diligence. It takes moral clarity. It takes
ingenuity. And above all, it takes a willingness to try.”
Atul Gawande, 2007

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Contents
PART 1: VALIDATION OF THE WIMAT COLONOSCOPY SUITCASE

Chapter 1: Introduction: The diagnosis, management and treatment of adenomatous polyps

1.1 Colorectal cancer and adenomatous polyps........................................................................... 21-26
a) Epidemiology, aetiology and pathogenesis...................................................................... 21
b) Classification of adenomatous polyps.............................................................................. 21-24
c) Management of adenomatous polyps............................................................................... 24

d) Colonic polyp surveillance in the UK............................................................................... 24-25
e) NHS bowel cancer screening Programme (NHS BCSP).................................................. 25-26
1.2 Colonoscopic polypectomy......................................................................................................... 26-30
a) Hot and Cold Biopsy......................................................................................................... 26-27
b) Snare polypectomy............................................................................................................ 27-28
c) Endoscopic Mucosal Resection (EMR) / Endoscopic Submucosal Dissection................ 28-29
d) Complications following colonoscopic polypectomy........................................................ 29-30
1.3 Training and assessment in colonic polypectomy.................................................................... 30-35
a) Colonoscopy certification and current assessment procedure......................................... 30-32
b) Subjective assessment in colonoscopic polypectomy........................................................ 33

c) Objective assessment in colonoscopic polypectomy......................................................... 33-34

d) Self-assessment................................................................................................................. 35

1.4 The use of simulation in colonoscopy training......................................................................... 35-42
a) Mechanical simulators / box trainers............................................................................... 37

b) Live Animal Simulators.................................................................................................... 38

c) Virtual Reality Simulators................................................................................................ 38
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d) Ex-vivo Animal Tissue Simulators…………………………………………………………….. 38-39

e) The WIMAT colonoscopy suitcase.................................................................................... 39-40
f) The requirements of a training simulator......................................................................... 41

g) Summary........................................................................................................................... 42

1.5 Aims and Hypotheses................................................................................................................. 42

a) Aims.................................................................................................................................. 42

b) Hypotheses........................................................................................................................ 42

Chapter 2: Review of literature: A systematic review of validity testing in colonoscopic simulation
2.1 Introduction................................................................................................................................ 44

2.2 Methodology............................................................................................................................... 44-45

a) Inclusion and exclusion criteria....................................................................................... 45

b) Outcome measures........................................................................................................... 45

2.3 Results......................................................................................................................................... 45-57
a) Search strategy and findings............................................................................................ 45-46
b) The type of simulators included in the review.................................................................. 46-47
c) Evidence for the face / content validity of colonoscopy simulators................................. 48
d) Evidence for the construct validity of colonoscopy simulators........................................ 48-49

e) Construct validity of the GI mentor II.............................................................................. 50

f) Construct validity of the Accutouch HT Immersion......................................................... 50

g) Construct validity of the Olympus Endo Ts-1 (2nd Generation)..................................... 51

h) Evidence for the criterion validity of colonoscopy simulators......................................... 51-57

2.4 Discussion.................................................................................................................................... 58-63

a) Summary of review work.................................................................................................. 58

b) VR Validation................................................................................................................... 58

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