Preoperative Warm-Up Using a Virtual Reality Simulator.

2011·0.49 MB·English

by  Moldovanu, Radu

S P
CIENTIFIC APER
Preoperative Warm-Up Using a Virtual Reality
Simulator
Radu Moldovanu, MD, PhD, Eugen Taˆrcoveanu, MD, PhD, Gabriel Dimofte, MD, PhD,
Cristian Lupas¸cu, MD, PhD, Costel Bradea, MD, PhD
ABSTRACT “time and motion” and “overall impression” tend to be
better after warm-up, but differences failed to reach sta-
Background and Objectives: All modern surgical pro-
tistical significance in our series.
ceduresrequireahighlevelofcognitiveandpsychomotor
skillsachievedusingdifferenttrainingmethods,butcould Conclusion: Surgeons, even the most experienced in
be influenced by fatigue and other psychological factors. laparoscopic surgery, can increase specific psychomotor
We evaluated the effect of warm-up exercises on opera- skills associated with a laparoscopic environment by do-
tive laparoscopic performances. ing simple exercises on a virtual reality simulator, just
beforeanoperation.Theseimprovementsarereflectedin
Methods: The surgical team operated on a consecutive
moreaccuratehandlingoftissueduringlaparoscopiccho-
series of 20 patients with gallstones. Patients were ran-
lecystectomy.
domly allocated in 2 groups: group A to be operated on
without warm-up exercises and group B to be operated Key Words: Laparoscopic education, Warm-up, Com-
on after a short-term warm-up. All the patients were op- puter simulation, Cholecystectomy.
eratedonbythesamesurgicalteam.Thefull-timerecords
oftheoperationwereanalyzedby2independentreview-
ers.AmodifiedsimplifiedGlobalRatingScore(GRS)was
usedtoassessthesurgicalprocedures.Atrainingmodule
INTRODUCTION
using the Lap Mentor simulator was designed for the
warm-up. Surgeryisaskill-basedprofession.Manymodernsurgical
procedures and especially minimally invasive techniques
Results:Betterperformanceswerenotedbybothobserv-
require a high level of cognitive and psychomotor skills,
ers in group B only regarding “Respect for tissue” scores
and could be influenced by fatigue as well as other psy-
(3.75(cid:1)0.16 vs 4.43(cid:1)0.20, P(cid:2).021 and 3.87(cid:1)0.22 vs
chologicalfactors.1Allotherprofessionswithcomparable
4.57(cid:1)0.20, P(cid:2).041) achieving significant or marginally
cognitive and psychomotor skill requirements (eg, danc-
significant differences for all categories; GRS scores for
ers, musicians) use some warm-up exercises to enhance
their abilities.2 It was demonstrated that a 15-minute to
20-minute warm-up led to a 33% overall reduction in
SeniorSurgeon,AssistantProfessorofSurgery,FirstSurgicalUnit,“St.Spiridon”
HospitalIas¸i,UniversityofMedicineandPharmacy“Gr.T.Popa”Ias¸i,Romania(Dr. errors in a series of exercises that simulated surgical
Moldovanu). skills.2 However, it is not clear “whether improved task
SeniorSurgeon,ProfessorofSurgery,FirstSurgicalUnit,“St.Spiridon”HospitalIas¸i, performancewilltransfertoimprovementintheoperation
UniversityofMedicineandPharmacy“Gr.T.Popa”Ias¸i,Romania(Dr.Taˆrcoveanu).
room.”2
SeniorSurgeon,AssociatedProfessorofSurgery,FirstSurgicalUnit,“St.Spiridon”
HospitalIas¸i,UniversityofMedicineandPharmacy“Gr.T.Popa”Ias¸i,Romania(Dr.
Dimofte). MATERIALS AND METHODS
SeniorSurgeon,AssociatedProfessorofSurgery,FirstSurgicalUnit,“St.Spiridon”
HospitalIas¸i,UniversityofMedicineandPharmacy“Gr.T.Popa”Ias¸i,Romania(Dr.
Surgical Team and Procedures
Lupas¸cu).
SeniorSurgeon,AssociatedProfessorofSurgery,FirstSurgicalUnit,“St.Spiridon”
HospitalIas¸i,UniversityofMedicineandPharmacy“Gr.T.Popa”Ias¸i,Romania(Dr. One experienced surgical team (1 senior surgeon and 1
Bradea). cameraman) was selected for the experiment, lead by a
Addresscorrespondenceto:RaduMoldovanu,MD,PhD,FirstSurgicalUnit,“St. senior surgeon with substantial experience in laparo-
Spiridon” Hospital, 1 Bd Independen¸tei, 700111, Ias¸i, Romania, University of scopic cholecystectomy (over 1000 procedures per-
MedicineandPharmacy“Gr.T.Popa”Ias¸i.Telephone:[phone],Fax:0040
formed). All procedures were performed by the senior
232218272,E-mail:[email protected]
surgeon as the main operator, and the study aimed at
DOI:10.4293/108680811X13176785204409
evaluatingthisoperator’spsychomotorskillswithorwith-
©2011byJSLS,JournaloftheSocietyofLaparoendoscopicSurgeons.Publishedby
theSocietyofLaparoendoscopicSurgeons,Inc. out a warm-up. The team agreed to follow the protocol
JSLS(2011)15:533–538 533
ThePreoperativeWarm-UpUsingaVirtualRealitySimulator,MoldovanuRetal.
regardingrandomassignmentofcasestoeachstudyarm,
without prior information. Patients involved in the study
protocol were chosen consecutively from the elective list
regardlessofclinicalformorultrasoniccharacteristics.All
procedures were performed using a standardized ap-
proach, with the patient in the “American” position and
both operators situated on the left side of the patient. A
standard laparoscopic set of instruments was used with a
high-definition laparoscopic camera that allowed for dig-
ital recordings. The surgical team had all the freedom to
choose the operative approach as well as to choose to
convert to an open approach.
Exclusion criteria were history of open surgery in the
upperabdomenandacutecholecystitisdiagnosedbefore
randomization, major changes in technique due to asso-
ciateddiseasesdiagnosedduringexploratorylaparoscopy
Figure 1. Virtual reality simulator warm-up tasks: (1) Camera
anddifficultcholecystectomy(difficultylevel3or4,using
navigation; (2) Instrument coordination; (3) Clip applying; (4)
Cuschieri classification3). We decided to exclude such Clipping and grasping; (5) Electrocautery; (6) Cystic pedicle
cases to separate errors generated by nonoptimal coordi- dissection;(7)Cysticpedicleclippingandcutting.
nationandimpropersurgicalskills,fromthosethatcould
beassociatedwithdifficultanatomicalsituations,inflamed
regardlessofclinicalformorultrasoniccharacteristicsthat
tissue, and severe adhesions. Pooling these cases in the
couldpredictadifficultcholecystectomy.Theseriesof20
series might confound evaluators in their analysis and
patientswererandomlyassignedto2groupsusingonline
increase the variability in the sample cohort.
randomizer software (www.randomizer.org): group A –
Warm-up Tasks patientstobeoperatedonwithoutwarm-upexercisesand
group B – patients to be operated on after a short-term
We used a Lap Mentor simulator (Simbionix, Cleveland,
warm-up task. All procedures were recorded in DVD
OH), which combines a PC running Windows XP, a con-
formatandanalyzedby2independentreviewerstoassess
sole that simulates the patient’s abdomen with 3 trocars
the surgeons’ skills. The evaluators were blinded for pa-
already inserted, and complex software with different
tientrandomizationstatusandpostoperativefollow-up.A
modules and tasks. We used a console that allows for
simplifiedGlobalRatingScale/Score(GRS)7,8wasusedto
forcefeedbackthataddsatactilesensetotheartificial3D
assess the surgical procedures (Figure 2). The modified
environment.LapMentorhasgoodconstructvaliditypro-
scale consisted of 6 categories: 1) respect for tissue (aim-
vidingthepossibilitytodistinguishbetweensubjectswith
ing for errors in tissue handling, unwanted movements
varyinglaparoscopicexperience.4,5Accordingtoourpre-
thatproducedisruptionoftissue,gallbladderwallbreaks,
viousexperienceinlaparoscopictraining,6wedesigneda
cystic duct or cystic artery lesions, or errors generating
training module consisting of 7 measurable tasks consid-
avoidable lesions in the liver or surrounding tissues); 2)
ered important in laparoscopic cholecystectomy module
time and motion progress (aiming for unwanted move-
(Figure 1): 1) camera navigation; 2) instruments coordi-
ments or badly predicted amplitude of movements of the
nation; 3) clip applying; 4) clipping and grasping; 5)
operator, as well as a bad coordination between laparo-
electrocautery; 6) cystic pedicle dissection (critical view);
scopeandoperatingfield);3)instrumenthandlingandsafety
7) cystic pedicle clipping and cutting. The subject had to
(aiming mostly at errors in handling of instruments – eg,
fulfill a training module at his own pace ((cid:3)15 to 20
cross-over, unnecessary touching, abnormal movements,
minutes),justbeforethesurgicalprocedure.Timeinterval
errorsinsafetyregardingcoagulationandmanipulationof
between the preoperative warm-up and the start of the
adjacent organs); 4) depth perception (aiming at errors
surgical procedure could not exceed 15 minutes.
generated by the adjustment process to bidimensional
representationofthespace,eg,malpositionoftheinstru-
Skills Assessment
mentinfrontorbehindstructures);5)bimanualdexterity
Patients involved in the study protocol were chosen con- (aimingaterrorsgeneratedbymisuseofthenondominant
secutively from the elective list of the operating surgeon, hand, which results in difficulties in exposure) and 6)
534 JSLS(2011)15:533–538
Figure2.GlobalRatingScale/Score(GRS)usedtoassessthesurgicalprocedures.
overall impression (which intends to offer a general im- Statistical Analysis
pression regarding the whole procedure, rather than a
Collected data were coded as categorical or numerical
sum of all previous scores). Each category was scored
variables included in an MS Access Office XP database
from 1 to 5 on a Likert-type scale. Additional data were
andstatisticallyanalyzedusingSPSSversion15.0forWin-
alsorequired:operatingtime(recordedfromtheinsertion
dows(StatisticalPackagefortheSocialSciences,Chicago,
of the laparoscope until removal of the gallbladder from
IL, USA). The univariate analysis was conducted with the
theliverbed)andcholecystectomydifficulty.Thedifficult
Student t test for numerical variables and Pearson (cid:1)2 test
cholecystectomiesgradedas“3”or“4”(conversion)were
for categorical variables; P(cid:4).05 was considered statisti-
excluded from the final analysis.
cally significant. Average values for continuous variables
were reported as mean (cid:1) SEM (Standard Error of Mean).
Reviewerswereaskedtoevaluateonlypsychomotorskills
Spearman’s rho test was used to test interobserver vari-
in this experiment. Scales are subjective, but reviewers
ability; the strength of the relationship was interpreted as
were instructed to identify errors and pitfalls in laparo-
little or no relationship (R(cid:2)0 to 0.25), weak to fair
scopic manipulation, navigation, and safe handling of
(R(cid:2)0.25 to 0.5), moderate to good (R(cid:2)0.5 to 0.75), and
tissue during the whole procedure. Special care was di-
excellent (R(cid:5)0.75).10
rected towards adjusting to depth perception and good
control of the instruments, as these could be relevant to
the preoperative warm-up.
RESULTS
To increase the sensitivity of evaluation, each GRS cate- Of the 20 study procedures, 5 were excluded due to the
gorywasseparatelynoted(Figure2):1)exposureofthe difficulty of the procedures: 3 cases noted as difficulty
biliary region, including adhesiolysis; 2) dissection of the level “3” and 2 conversions to open surgery (difficulty
cysticpedicle(includingthequalityof“criticalview”)9;3) level “4”). Fifteen procedures were further analyzed.
the final dissection of the gallbladder; and 4) global cate- There were no complications in either group, and all
gory score. Due to marked subjectivity in evaluation, we patients were discharged 48 hours to 72 hours after sur-
preferred to present results from each evaluator, rather gery, according to hospital protocol. The man to woman
than pool the data. This allowed for more objectivity ratio was 7 to 8, and the mean age was 45.73(cid:1)3.49 years
regardingthewholeexperiment,whiledatawereconsid- (range, 27 to 68). Eight patients (53.3%) were in Group A
ered significant when both evaluators’ data were concor- (without warm-up) and 7 (46.7%) were in Group B (with
dant. warm-up). The mean age and BMI were similar in the 2
JSLS(2011)15:533–538 535
ThePreoperativeWarm-UpUsingaVirtualRealitySimulator,MoldovanuRetal.
groups. Difficulty levels were similar in the 2 groups as sion” (Tables 2 and 3), but we cannot say that warm-up
evaluated by the independent evaluators (no significant significantly optimizes the psychomotor skills mentioned
differences between groups, P(cid:2).338): difficulty level “1”, here.
73.3% (n(cid:2)11) and difficulty level “2”, 26.7% (n(cid:2)4). Op-
erative time was not an endpoint measurement in this
DISCUSSION
study. Even so, the mean operative time of 27(cid:1)2.44 min-
utesisconsistentwiththedegreeofdifficulty.Alsolackof It is well known that minimally invasive surgical proce-
significant differences between groups (P(cid:2).717) advo- dures (MIS) require specific psychomotor and cognitive
cates for the homogeneity of procedures in both arms of capabilities that are different from those used in conven-
the study. tionalopensurgery(eg,accurateinstrumenttargetingina
3-dimensional environment using a bidimensional video
Surgeon’s Skills Assessment Data interface, bimanual dexterity, laparoscopic anatomic par-
ticularities).11–14 These capabilities can be gained and im-
DataconfirmedthatevaluationofeachGRSscoreishighly
proved through extensive training.15 It was demonstrated
subjective as can be easily demonstrated by low interob-
that the specialized training for MIS is absolutely neces-
server variability scores (Tables 1 through 3). That is
sary to avoid or to minimize intraoperative errors.16–18
mostly due to lack of numerical analysis of task perfor-
mance in the operative environment, as opposed to sim-
The beneficial role of virtual reality training for MIS has
ulation.Basedonthis,ouroptionwastoseparatelycom-
been demonstrated, especially for beginners; a recent
pute the results of each reviewer and consider results
metaanalysis revealed shorter time taken to complete a
significantinthesituationwhenbothevaluationssuggest
laparoscopic task, increased accuracy, decreased number
a statistically significant (or marginally significant) differ-
of errors, and better “composite operative performance
ence in favor of preoperative warm-up.
score”forthetraineeswhousedvirtualrealityasatraining
The only obvious improvement in psychomotor skills af- method.19 Moreover, virtual reality simulators record dif-
terwarm-upwasdemonstratedwithstatisticalsignificance ferent parameters (eg, time, misses, drift, trajectory, and
inGRSscoresfor“Respectfortissue.”GroupBdidbetter angularpathoftheinstruments,tissuedamage)thatallow
as evaluated by each reviewer, and scores improved to for an objective evaluation of the trainees’ psychomotor
significant or marginally significant better results. It is performances.6,13 It was recently demonstrated that psy-
notable that differences are evident in every category chomotorperformancesmeasuredbyvirtualrealitysimu-
analyzed (Table 1). lators correlates with intraoperative performances.20
For all other GRS issues, “time and motion,” “instrument We used a virtual reality simulator to perform the
handlingandsafety,”“depthperception,”“bimanualdex- warm-up exercises. Based on our previous experience in
terity,” and “overall impression” the scores were better in MIStraining,6wechoseacombinationoftaskscapableof
group B, but differences fail to achieve statistical signifi- optimizingpsychomotorskillsthatcouldbefulfilledin15
cance.Differencesareconsistentinalmosteverycategory minutesto20minutes.Itwasourintentiontolookfordata
forissuesregarding“timeandmotion”andoverallimpres- that may suggest an improvement in psychomotor skills
Table1.
RespectforTissue’sScores
Evaluator1 Evaluator2 IOVa
GroupA GroupB P GroupA GroupB P R
Exposureofbiliaryregionandadhesiolysis 3.88(cid:1)0.35 4.71(cid:1)0.18 .059 3.88(cid:1)0.29 4.71(cid:1)0.18 .037 0.842b
Dissectionofthecysticpedicleandcriticalview 3.38(cid:1)0.18 4.43(cid:1)0.29 .008 3.88(cid:1)0.29 4.71(cid:1)0.18 .037 0,623
Dissectionofthegallbladder 3(cid:1)0.18 4(cid:1)0.31 .014 3.63(cid:1)0.32 4.43(cid:1)0.20 .058 0.583
Overallissuescore 3.75(cid:1)0.16 4.43(cid:1)0.20 .021 3.87(cid:1)0.22 4.57(cid:1)0.20 .041 0.350
aInterobservervariability.
bP(cid:4).05.
536 JSLS(2011)15:533–538
Table2.
TimeandMotionScores
Evaluator1 Evaluator2 IOV*
GroupA GroupB P GroupA GroupB P R
Exposureofbiliaryregionandadhesiolysis 4.50(cid:1)0.32 4.29(cid:1)0.18 .593 4.13(cid:1)0.35 4.57(cid:1)0.20 .308 0.397
Dissectionofthecysticpedicleandcriticalview 4(cid:1)0.26 4.57(cid:1)0.29 .175 3.88(cid:1)0.12 4.71(cid:1)0.18 .002 0.507
Dissectionofthegallbladder 4.38(cid:1)0.26 4.57(cid:1)0.20 .573 4(cid:1)0.19 4.57(cid:1)0.20 .059 0.560
Overallissuescore 4.25(cid:1)0.16 4.71(cid:1)0.18 .081 4(cid:1)0.19 4.86(cid:1)0.14 .004 0.577
aInterobservervariability.
Table3.
OverallImpressionScores
Evaluator1 Evaluator2 IOV*
GroupA GroupB P GroupA GroupB P R
Exposureofbiliaryregionandadhesiolysis 4.50(cid:1)0.27 4.86(cid:1)0.14 .279 4.25(cid:1)0.25 4.43(cid:1)0.20 .595 0.361
Dissectionofthecysticpedicleandcriticalview 4.13(cid:1)0.22 4.71(cid:1)0.18 .069 4.25(cid:1)0.25 4.71(cid:1)0.18 .169 0.617
Dissectionofthegallbladder 4.25(cid:1)0.16 4.71(cid:1)0.18 .081 4.13(cid:1)0.22 4.71(cid:1)0.18 .069 0.364
Overallissuescore 4.37(cid:1)0.18 4.86(cid:1)0.14 .059 4(cid:1)0.19 4.86(cid:1)0.14 .004 0.516
aInterobservervariability.
for this specific operation if the surgeon proceeds with scores in “respect for tissue” may reflect a more precise
laparoscopic cholecystectomy within 15 minutes after handling of anatomical structures, with less damage to
completion of warm-up. structures during manipulation or dissection.
Evaluation of surgical performance is difficult, and no Datashouldbeinterpretedregardingthepotentialbenefit
method is universally accepted. Different possibilities ofwarm-upforaveryexperiencedsurgeon,performinga
have been described in the literature: VR simulator re- highly standardized procedure. The present study has
corded data, checklists, and global scores, assessment some limitations: a relatively small number of cases, a
using electromagnetic tracking devices or video tracking single and very experienced surgeon, and the use of a
devices.7,8,12,13,15,21,22 We used GRS and 2 independent “globalscore”formeasurementofresults.Furtherstudies
observers to evaluate the operative performances, similar should include more surgeons with different MIS experi-
to other studies in the literature.7,8,23 The low interob- ence. One hypothesis is that inexperienced surgeons
server variability is proof of the subjective evaluation us- might benefit more from this warm-up procedure in op-
ingGRSscores,andweconsequentlylookedforasimilar timizing psychomotor skills, and the impact may decline
patternofchangesineachcategoryandforeachobserver. asexperienceaccumulates.Weshouldalsooptimizeeval-
Our hypothesis is that there might be an optimization if uation methodology with a more accurate and directly
both observer scores are better in group B, even if abso- measurable scoring system, but also adaptation of the
lute values are not concordant between the 2 of them. warm-up procedure for more complex procedures may
revealabeneficialincreaseinpsychomotorskillsinaless
Our results revealed significant better performances after
familiar environment.
a short warm-up only in the GRS category “respect for
tissue” while other GRS categories (“time and motion,”
CONCLUSION
“instrument handling and safety,” “depth of perception,”
“bimanual dexterity,” and “overall impression”) were not Using a virtual reality simulator and doing simple exer-
significantly influenced by the warm-up exercises. Better cises before the operation, the surgeons, even the most
JSLS(2011)15:533–538 537
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