Surgeon Ergonomics in Robotic-assisted Laparoscopic Vs Standard Laparoscopic Surgery
Surgeon Ergonomics in Robotic-assisted Laparoscopic Vs Standard Laparoscopic Surgery
Musculoskeletal injuries amongst surgeons are prevalent. This project will determine whether
 Robotic-assisted Laparoscopic surgery (RALS) offers superior benefits to surgeon's
 musculoskeletal health than standard laparoscopic surgery (LS), by identifying the
 comparative changes in muscle fatigue during RALS Vs LS surgical procedures, and additionally
 identify any cognitive effects of this. The Study if successful, could help reduce injury
 rates in surgeons.
The number of surgical procedures being performed using minimal access techniques is on the
 rise because of improved recovery times for patients. Thus, surgeons are performing an
 increasing number of endoscopic/laparoscopic procedures and are operating for longer periods.
 A recent meta-analysis showed that work-related musculoskeletal injuries amongst surgeons are
 common (1) and surgeons are amongst those most at risk of work-related musculoskeletal
 decline (2). Indeed, the prevalence of degenerative spinal disease is 17%, rotator cuff
 pathology 18%, and degenerative lumbar spine disease is 19% (1). Surgeon's experience
 work-related musculoskeletal pain in addition to injury, and pain is highly prevalent in the
 neck (48%), shoulder (43%), and back (50%) (13).

 According to the Office for National Statistics in the UK, musculoskeletal problems amongst
 the workforce are the second most common cause for absence (17.7%) and account for 23 days
 absence/year (2). This is not dissimilar in the US where the Bureau of Labour Statistics
 estimates that 62% of all worker injuries and 32% of missed days from work result from
 musculoskeletal problems. Collectively, these data suggest that musculoskeletal problems
 caused by careers in surgery can reduce physical health, which is associated with reduced
 productivity, career longevity, and even the quality of patient care.

 Robotic-assisted laparoscopic surgery (RALS) is a modern technology that could help mitigate
 these musculoskeletal problems and thereby improve patient care. In comparison to standard
 laparoscopic surgery (LS), RALS offers steadier wrist movements with a reduced fulcrum
 effect, thus benefiting the patient (3). There is emerging evidence that RALS is associated
 with a lower rate of musculoskeletal problems (23-80%) than LS (70- 100%) (1). RALS may
 therefore be an attractive alternative to LS, despite the high cost of equipment and steep
 learning curve during training.

 No study has compared the demands of RALS vs. LS on musculoskeletal fatigue (and subsequent
 injury risk) and whether these changes are underpinned by changes in cognitive fatigue. The
 investigators aim to determine whether a career using RALS is associated with better
 musculoskeletal health for surgeons than standard LS when performing complex minimally
 invasive procedures.

 The hypothesis is that RALS will reduce musculoskeletal fatigue and the prevalence of
 musculoskeletal injury in surgeons compared to LS. If this is true, RALS should receive
 increased support through preserving surgeon's health and thereby reducing costs for
 healthcare providers.

 Research subjects (surgeons and patients) Surgeons: Investigators will recruit surgeons
 completing surgical procedures who have similar levels of experience between RALS and LS
 groups. Surgeons will fill a questionnaire regarding working hours and experience, physical
 activity level (e.g., sport, bicycling to work or gardening), general health conditions and
 musculoskeletal symptoms within the last 12 months using the Standardized Nordic
 questionnaires for the analysis of musculoskeletal symptoms (11). The investigators will also
 quantify body composition (height, body weight, BMI, muscle mass, fat mass) using
 clinically-validated bioelectrical impedance analysis. Surgeons will broadly be matched for
 age and surgical experience, anthropometry, and sex. Patients: To complete the work, the
 investigators will use data from n = 40 patients being operated upon in RALS and n = 40 LS
 groups that will be age, sex, BMI, and pre-operative risk score matched.

 Surgical procedure and overall study design Data will be collected during index procedures:
 For example prostatectomy or anterior resection using either RALS or LS. Before surgery,
 surgeons are fitted with both EMG (to measure muscle fatigue) and EEG (to measure cognitive
 fatigue). Surgeons will complete a series of validated questionnaires before and after each
 surgery to subjectively determine musculoskeletal strain/pain and cognitive fatigue.

 This research is being conducted in real-life surgery and controlling conditions between
 operations is uniquely challenging. The study will exclude any operations where complications
 result in the surgery taking beyond 50% of the mean average surgery time, to prevent this
 skewing the data towards an effect for musculoskeletal fatigue. This mean average time will
 also include for specific procedures e.g. Prostatectomy - defining resection margins by
 dissecting the endopelvic fascia and mobilising seminal vesicles, rectum and bladder neck,
 defining and transecting the prostatic pedicles; transecting the bladder neck, urethra, and
 prostate; anastomosing the urethra to bladder neck. Bowel surgery - identifying, transecting
 and ligating the pedicle; lateral mobilisation and preserving ureters, and bowel anastomosis.

 The investigators will assess acute fatigue by comparing RALS and LS within a single surgery
 that is the first surgery of any given day. To determine the cumulative fatigue (chronic
 effects of surgery, aim 2), comparison will be made between the subject's first and last
 surgery of the day when >2 surgeries have been completed.

 Measurement of musculoskeletal fatigue (EMG) EMG justification. The study will utilise
 electromyography (EMG) to determine acute and chronic changes in musculoskeletal demands
 associated with RALS and LS surgery. Surface EMG is a non-invasive procedure that measures
 muscle activity by recording the electrical signal generated during muscle fibre recruitment.
 Its ability to assess fatigue has been long established (e.g. (4)) and it has been widely
 used in many populations, including athletes (e.g. (5)), dentists (6) and surgeons (e.g.
 (7,8)) EMG will be collected for 200 s (9) at 0, 30, 60, 90 and 120 minutes of a ~2-hour
 surgical procedure. In addition to these time points, EMG data will be collected during
 clinically important tasks (e.g. suturing upon completion of surgery, which typically will
 take 10 minutes).

 EMG protocol. Surgeons will provide written informed consent prior to participation. Surgeons
 will be completing index procedures: For example prostatectomy or anterior resection using
 either RALS or LS; the protocol for EMG data collection will be identical. Before surgery,
 surgeons will be fitted with wireless EMG sensors. The EMG data collection procedures will
 follow established protocols regarding site preparation and electrode placement, as well as
 data collection, processing and normalisation (7,12). Briefly, the site will be shaved and
 cleansed with alcohol wipes, with the bipolar electrodes placed on the belly of the muscle
 and parallel to the muscle's fibres having an inter-electrode distance of 20mm (12).
 Electrodes will be placed on muscles of the arm, neck, shoulder and back e.g. flexor carpi
 radialis muscles, biceps muscle, bilaterally from the trapezius muscles, and bilaterally from
 the erector spinae muscle. These muscles have been selected based on a recent meta-analysis
 (13). Electrodes are fitted before surgeons' scrub for surgery and electrodes will be covered
 by surgical gowns thereby maintaining a sterile theatre. A wireless EMG system has been
 selected so that it is minimally invasive and does not impede a surgeon's movement with
 wires.

 EMG data analysis. Data will be collected and analysed using EMG Works (Delsys Inc., Boston,
 MA, USA), with recommended normalisation, sampling, filtering and smoothing techniques (7).
 EMG recordings in previous data show significant changes during LS procedures in 70 - 85% of
 surgeons, mainly in neck, shoulders, hands, lower back, and lower extremities muscles. The
 recordings from muscles of the arm, neck, shoulder and back will be monitored but lower limb
 muscles will not be included because during RALS, Surgeons are seated away from the patient
 and having brow- and armrests considerably modifies the workload on the lower limbs making
 comparisons of lower-limb muscles in LS not meaningful. Once the EMG signal has been
 normalised (10), basic EMG variables, such as frequency and amplitude, can provide
 information on how muscle fibre recruitment has changed, both at a single muscle as well
 across several muscles (activation / recruitment strategies), while a fatigue score can also
 be calculated (11). The normalisation process can afford the ability to compare between
 muscles as well as examine the muscles' activity different time points (i.e. within the same
 session or after a longer time has elapsed; e.g. (5,12,13).

 Measurement of cognitive fatigue (EEG) EEG justification. The study will use
 electroencephalography (EEG) to determine if acute or chronic changes in musculoskeletal
 demands are associated with changes in motor control and cognitive fatigue. Cognitive fatigue
 can be determined via neurophysiological measures, such as the electroencephalogram. The EEG
 can measure the ongoing electrical activity of the brain during a given task, such as whilst
 driving or during surgery. EEG measures of fatigue can provide an objective quantification of
 an individual's cognitive state in real-time, removing reliance on subjective measures such
 as self-report or questionnaires that have been found to be unreliable for moderate fatigue
 states. The brain oscillates at a number of different frequencies at any given time, and this
 information is recorded in the EEG. The power of certain frequency bands has been taken as a
 proxy to index cognitive fatigue. Specifically, evidence indicates that alpha-band power
 (7-13 Hz) is sensitive to fatigue (for a review see (14)), and has been used to measure
 driver fatigue both in real-traffic and simulation exercises (15- 18). When fatigue
 increases, alpha-band activity occurs in bursts of 500 milliseconds, which are known as alpha
 spindles (19). Alpha spindles are considered to reflect individual fatigue states and can be
 quantified in terms of their peak frequency, duration, and amplitude, giving rise to an
 individual's alpha signature (20).

 EEG protocol. Whilst surgeons are having EMG electrodes fitted, a similar procedure will be
 completed for the wireless EEG electrodes. The skin site on the head will be prepared as
 previously described (21) and the electrode gel and electrode cap will be applied before the
 surgical cap, thereby maintaining the sterility of the surgical theatre. Electrodes will be
 placed over the cortex using an 8-channel electrode montage to record ongoing EEG
 oscillations during surgery for 200 s (9) at 0, 30, 60, 90 and 120 minutes of a ~2-hour
 surgical procedure. Electrodes will be positioned according to the 10-20 international
 electrode placement system. The main EEG channels of interest will be positioned over the
 occipital and parietal cortex, namely electrode locations O1, O2, P3, P4, P7, P8 where
 maximal alpha activity can be detected. In addition to these time points, EEG data will be
 collected during clinically important tasks (e.g. suturing upon completion of surgery, which
 typically will take 10 minutes). A wireless EEG system has been selected so that it is
 minimally invasive and does not cause distraction or restriction due to movement of wires.

 EEG data analysis. Data will be collected and analysed using Enobio 8 5G (Neuroelectrics,
 Cambridge, MA, USA) using standard referencing, sampling, filtering and smoothing techniques
 (21). Investigators will compare peak alpha power, and alpha spindle duration and amplitude,
 in RALS compared to LS. Changes in EEG power spectra, specifically in the alpha frequency
 band, will be used to monitor alertness, and will provide crucial information about whether
 cognitive fatigue, underpins any musculoskeletal fatigue. The study will also be able to
 identify how alertness changes over time during surgery through the EEG power spectra.

 Measurements of surgeon physical activity and musculoskeletal health It is vital that
 musculoskeletal fatigue in the surgeons is not influenced by anything other than the work
 environment. We will use tri-axial accelerometery every week throughout data collection to
 measure and ensure surgeons are not changing their physical activity patterns (and thus
 getting stronger or weaker). Nutrition is also critical in the development of strength, just
 like poor nutrition can lead to strength loss. Therefore, surgeons will complete 3-day food
 diaries and dietary analysis at weekly intervals throughout the data collection period.

 Statistics and data analysis. Power calculation: To address aim 1, The investigators
 anticipate a difference in musculoskeletal fatigue of 20% between RALS and LS based upon the
 limited evidence available (1). Therefore, based on a predicted effect size (Cohen's d) of
 0.82, recruitment of 40 subjects in RALS and 40 subjects in LS (total sample size n = 80)
 will be carried out. These numbers will be matched between prostate and bowel surgeries. In
 aim 2, data suggest that the level of fatigue between the last surgery of the day versus the
 first will be greater than the difference in aim 1 (Cohen's d 0.90), therefore 27
 subjects/group are required for this research question. Lastly in aim 3 to investigate
 whether changes in musculoskeletal fatigue are underpinned by changes in motor control and
 cognitive fatigue, The investigators anticipate an effect size of 0.85 between RALS and LS
 and therefore will use data from the 31/group to study this effect. An A priori power
 calculation will be used to compute the required sample size using G*Power 3 (22).
 Conservatively, the lower of the three values for the power calculation (an effect size of
 0.82) has been chosen. Assuming a Cohen's d of 0.82 requires 40 participants per group for
 90% power to detect a difference between groups, at an alpha of 0.05.

 Statistical analysis: To determine differences in musculoskeletal and cognitive fatigue in
 RALS and LS, a mixed-model ANOVA or non-parametric equivalent will be utilised. The data and
 conclusions arrived at the end of the study will inform recommendations both in scientific
 literature (publications) and dissemination at conferences towards the end of the project
 (see Gantt chart). The study is the platform to develop a strong case regarding the long-term
 musculoskeletal effects on surgeons performing minimal access procedures in RALS.
Inclusion Criteria:

 -  Healthy surgeons with experience in performing procedures using LS and/or RALS.

 Exclusion Criteria:

 -  Significant co-morbidities

 -  Significant musculoskeletal symptoms

 -  Procedures that include major complications or requiring >50% more time than the mean
 average