Keywords laparoscopic training - suture training
Palavras-chave treinamento laparoscópico - treinamento de sutura
Introduction
The revolutionary development of minimally invasive surgery has enabled the implementation
of new technologies in the medical practice with remarkable benefits in the treatment
of several diseases.[1 ] However, the pace at which these advances have been incorporated into medicine under
certain circumstances was not followed by the training and qualification of novice
surgeons,[2 ] or by the improvement of evaluation methods in training programs.[3 ]
It seems appropriate that, in addition to the skills required for open surgery (manual
dexterity, knowledge of anatomy and surgical techniques), the laparoscopic surgeon
develops other laparoscopy-specific skills, such as depth perception in a two-dimensional
screen, hand-eye coordination, bimanual coordination, the handling of long instruments
that provide less tactile feedback, and, finally, the knowledge of the laparoscopic
operating room.[4 ]
[5 ]
Although training in surgery is challenging, it seems obvious that a surgeon needs
to have theoretical and practical knowledge and skills prior to performing a laparoscopic
surgical intervention.[4 ]
[6 ]
[7 ]
[8 ]
[9 ]
Training with synthetic rubber models that mimic human tissues offers an opportunity
for beginners to practice unfamiliar techniques in an artificial environment, thereby
maximizing the acquisition and retention of knowledge in laparoscopy,[10 ] and potentially leading to a decrease in errors in the operating room[11 ] and optimizing the surgical time.[12 ]
In this context, the learning curve of laparoscopic suture is considered a challenging
task; suturing is probably the most difficult skill to master in endoscopic surgery.[13 ]
[14 ] The time required for suturing is also considered a potential obstacle in certain
surgical techniques. Therefore, it is important to concentrate efforts to develop
effective teaching tools to improve these skills.[13 ]
[14 ]
[15 ]
In our service, in order to meet the demand for advanced laparoscopic suture training,
we developed bimanual training protocols. We recommend the use of both hands to make
the intracorporeal knots following the technique called Romeo Gladiator Rule, which
was described by Armando Romeo.[16 ]
The maneuver was named Romeo Gladiator Rule because, during the knotting, the needle
holder performs a clockwise turn (from 6 to 12 o'clock) or a counterclockwise turn
(from 12 to 6 o'clock) with the jaws of the tip open. This maneuver resembles the
pollex versus gesture made by Roman emperors to announce a verdict of condemnation or mercy to
losing gladiators. The purpose of keeping the pollex versus , or the jaws of the needle holder, open is to help maintain the thread in place.[16 ]
[17 ]
During the preparation for knot tying, there are some rules that must be followed:
create two landmarks before starting the maneuver. The first reference point is the
home base, which is defined as the cylindrical area where the knot is placed. In a
right-handed surgeon's point of view, the assistant forceps (left hand) picks up the
thread 2 cm from the needle. The second reference point is the thread horizon, which
is defined as the rectilinear portion of the thread created by displacing the thread
to the opposite side to the assistant forceps ([Figs. 1 ] and [2 ]). In the next step, the needle holder (right hand) performs a clockwise or counterclockwise
turn with the jaws open, passing behind or in front of the thread horizon, depending
on the blocking sequence.[16 ]
[17 ]
Fig. 1 Home base.
Fig. 2 Thread horizon.
The aim of this study is to assess whether the training in laparoscopic suture with
the exclusive use of the dominant hand or with the use of both hands, by applying
the same suturing technique (Romeo Gladiator Rule), may influence the time it takes
to tie the knots, and their quality.
Methods
This study was approved by the Ethics Committee of Santa Casa de São Paulo. Before
the beginning of the study, we explained to the participants the aim, and how it would
be performed. Only the resident students who voluntarily agreed and signed the informed
consent form participated in the study.
The present study was a prospective observational study conducted at Santa Casa de
São Paulo; a total of 41 residents were selected for the study during 3 regular training
courses on laparoscopic suture between March 2016 and July 2016. All courses were
administered by the same team of teachers and instructors, and the lectures were the
same in the three courses.
The inclusion criteria of the study consisted of resident students in the second and
third years of gynecology/obstetrics and general surgery at Santa Casa de São Paulo
without prior training in laparoscopic suture.
All students attended a two-day training course on laparoscopic suture. The course
consisted of 5 hours and 30 minutes of a theoretical session, including the basic
topics for beginner surgeons (ergonomics, energy and suture), and 8 hours and 30 minutes
of a practical session involving hands-on training in a pelvic trainer simulator.
Romeo Gladiator Rule[16 ]
[17 ] was used to teach intracorporeal suturing using one or both hands to perform the
knot-tying technique. After the sessions, the residents were trained under the supervision
of an experienced professional, also called a tutor. The participants were stratified
and divided randomly into two groups at the beginning of the practical session. The
stratification was based on the result of the pretest performed before the beginning
of the course. Those who were able to perform the knot in the pretest were divided
into groups A and B. The randomization was performed using a random number generator,
and the generated numbers were stored in manila envelopes with the letters A or B
written on them.
The students from group A were divided into groups of 3 residents per work station,
and each work station was supervised by a tutor. In this group, the exercises proposed
were performed using only one hand, meaning that Romeo Gladiator Rule was performed
with the student's dominant hand.
The students from group B were also divided into groups of 3 residents per work station,
and were also supervised by a tutor. In this group, the exercises were performed following
the same technique, Romeo Gladiator Rule, but using both hands.
Each work station included 1 pelvic trainer ([Fig. 3 ]), which consists of a multiple-suture model connected to an all-in-one laparoscopic
video system (KARL STORZ, Tuttlingen, Germany) (monitor, light source, and video camera)
([Fig. 4 ]). A central 12-mm trocar-simulating transumbilical insertion of 10 mm optics, 0
degrees (using a Hopkins Straight Forward Telescope, Karl Storz SE & Co. KG, Tuttlingen,
Germany), and two 5-mm lateral trocars were introduced through the abdominal wall
of the pelvic trainer with two straight handle and curve tip needle holders (KOH Macro
Needle Holder, Karl Storz SE & Co. KG).
Fig. 3 EVA II Generation ETX A1 LAP (Pro-Delphus Simuladores Cirúrgicos, Olinda, Brazil).
Fig. 4 All-in-one video system.
First, a pre-test questionnaire was administered to obtain demographic data and information
concerning the previous surgical experience, previous laparoscopic suture training,
and the dominant hand.
Before the beginning of the activities, each participant had five minutes to tie a
complete intracorporeal knot under the supervision of a tutor. After the randomization
of the groups, we started the training, and the exercises were the same for all groups,
but they maintained the specific considerations of each group. The exercise in group
A was performed using the dominant hand; in group B, the same exercise was performed
with both hands.
The positioning of the trocars was the same in both groups. During this step of our
training program, the trocars were placed on the right and left sides of the pelvic
trainer.
Training on the first day focused on learning how to perform one basic knot, the half
knot, and the blocking sequence for the formation of a complete intracorporeal knot.
The exercises evolved step by step with the tying of the knot following the Romeo
Gladiator Rule, and each group had its respective blocking sequence.
For group A, the correct blocking sequence begins with a double half knot tied with
the dominant hand. For this knot to become a square double half knot, the surgeon
must uncross the thread, that is, cross the instruments. This is followed by one half
knot in the opposite turning direction from the prior double knot, thus forming a
stable square knot. To ensure the complete blocking of this knot, a third half knot
is made in the same direction as the initial double knot, or the opposite turning
direction of the second movement (
[Fig. 5 ]).
Fig. 5 Blocking sequence for group A – monomanual.
The blocking sequence for group B follows other characteristics: it begins with a
double half knot with the opposite hand passing the thread in the tissue. The thread
horizon takes a different position, and is opposite to the tail of the thread ([Fig. 6 ]). At the end of the knot, it is not necessary to uncross the threads or cross the
instruments. This is followed by one half knot with the opposite hand with a turning
movement in the same direction as the previous one. To block this sequence, a third
half knot is made with the same hand, and in the direction of the first double knot
([Fig. 6 ]).
Fig. 6 Blocking sequence for group B – bimanual.
On the second day, the training started with correct needle positioning exercises,
followed by the correct passage of the needle in the tissue by conducting exercises
about running sutures and always respecting the differences between groups A and B.
At the end of the course, the participants performed three exercises that assessed
the length of time to tie the knots and their quality. The parameters evaluated in
the final test were the time it took to to tie a complete intracorporeal knot, the
time it took to tie 10 consecutive half knots, the number of complete knots tied in
10 minutes, and an evaluation of the quality of the knots by the measurement of knot
loosening in millimeters using strength to open it.
Each exercise began when the tutor gave a signal, and ended when the resident finished
the knot, or when the predetermined time expired. Each tutor used a timer to record
the time required to perform each exercise. The resident was not allowed to receive
help, information, or corrections. The exercises were performed under the supervision
of a master tutor.
The final test was based on three different exercises:
Exercise 1: Measurement of the time it took to tie a complete intracorporeal knot. Each participant
had three chances to tie the complete knot, and an average of the time it took to
tie each knot was calculated. The timer was started with the visualization of the
two needle holders centralized in the monitor and after the passage of the thread
and the needle, which was performed by the tutor of each table. This passage was made
with the right hand.
Suture thread used: polyglactin 2–0, with a standard size of 18 cm.
Exercise 2: Measurement of the time it took to tie 10 consecutive half knots with the same thread
without cutting, thus obtaining a final result similar to a braid. The passage of
the needle was also performed by the tutor of each table, always with the right hand.
Suture thread used: polyglactin 2–0, with a standard size of 18 cm.
Exercise 3: Numbers of complete knots performed in 10 minutes on a fixed straw in a flat mold.
The time was recorded only for the tying of the knot made by the participant; the
timer was paused when the student cut the thread, and was restarted after the thread
and needle were passed by the tutor with the right hand. Therefore, the tutor's work
was not considered in the total time. Later, the straw was removed, thus enabling
the evaluation of the quality of the knots.
Materials used: suture thread - polyglactin 2–0, with a standard size of 25 cm (up
to 5 threads per participant); one 6-cm straw; and 2 pins to fix the straw in the
flat mold ([Fig. 7 ]).
Fig. 7 Flat mold with straw fixed.
The evaluation of the quality of the knots was performed with the assistance of two
engineers the day after at the engineering laboratory of the Brazilian headquarters
of the company called Medtronic. The suture molds were sent to the laboratory with
the straw fixed, which was removed at the knot evaluation.
First, we evaluated the quality of the thread (polyglactin 2–0) used in the tests.
One knot was made following the principles of the blocking sequence, and the thread
was cut in equal lengths from both sides of the knot. To evaluate the force required
to break the thread, it was placed in a dynamometer machine (Universal Testing Machine
5965, Instron, Norwwod, MA, US) and submitted to equivalent force traction in each
extremity until the thread broke ([Fig. 8 ]).
Fig. 8 Evaluation of the quality of the thread and thread breaks.
The maximum breaking strength of the thread was of 18 newtons (N), and the breaking
occurred at the level of the knot, the site of the greatest friction and fragility.
Based on this value of rupture strength (18 N), we chose a force value of 17 N because
our objective was to evaluate how much the knot loosens before the thread breaks.
The quality of the knots was evaluated using a caliper rule or pachymeter (Kingtools,
SP, Brazil) and dynamometer. First, we measured the length of the edges of the knot
with a pachymeter after the knot was submitted to traction with the dynamometer up
to a force of 17 N, and then, the length of the knot edges was measured again. The
difference between the length of the edges pre- and posttraction was evaluated to
obtain a measurement of knot loosening in millimeters (mm).
For the sample size calculation, we conducted a pilot study with twelve doctors participating
in a regular training course on laparoscopic suture offered by our department. They
were divided in two groups (monomanual and bimanual), and submitted to the same methodology
of training as previously described. Two exercises were used as the standard to calculate
the sample size: a) the amount of time needed to tie a complete intracorporeal knot;
and b) measurement of the knot loosening in millimeters. Using the data obtained in
this pilot study, applying a bicaudal test with a significance level of 95% and a
power of 80%, the suggested sample size was 20 subjects in each group.
The statistical analysis of all the collected information was initially performed
in a descriptive way.
In the present study, none of the variables followed a normal distribution; therefore,
we opted for data evaluation of the application of non-parametric tests. Variables
with non-normal distribution were expressed as medians (minimum-maximum variation).
The Fisher exact test was used to compare the qualitative variables, and the Mann-Whitney
test was used to compare the non-parametric continuous variables of the two groups.
The Wilcoxon test was used to compare the non-parametric continuous variables pre-
and post-training. For the inferential analysis, the significance level α was equal
to 5%. The statistical analysis was conducted using the Statistical Package for the
Social Sciences (SPSS, SPSS Inc., Chicago, IL, US), version 18.0 for Windows.
Results
The 41 participants who took part in this study were divided into group A (dominant
hand, with 21 participants) and group B (bimanual, with 20 participants). A total
of 21 participants were gynecology/obstetrics (GO) residents, and 20 were general
surgery (GS) residents. The average age of the study population was 27 years and 3
months, ranging from 25 to 30 years of age. Of the total, 14 participants were men
(34.1%) and 27 were women (65.9%). Only 3 (7.3%) participants reported the left hand
as preferred for the surgical practice.
All participants were subjected to a pretest, and 22 (53.7%) of them were able to
tie 1 knot in up to 5 minutes. A total of 5 (12.2%) participants performed the blocking
sequence correctly, and all participants used only the dominant hand.
Confirming the homogeneity of the sample, there was no statistically significant difference
between the groups with regards to the controlling variables: gender, dominant hand,
medical residency, and pretest knot performance ([Table 1 ]).
Table 1
Control variables between the groups of individuals submitted to monomanual (group
A) and bimanual (group B) laparoscopic suture training
Group
A
B
p -value
n (%)
n (%)
Gender
Female
17 (81)
10 (50)
0.078
Male
4 (19)
10 (50)
Dominant Hand
Right
19 (90.5)
19 (95)
1.000
Left
2 (9.5)
1 (5)
Specialty of the medical Student
Gynecology/obstetrics
10 (47.6)
11(55)
0.873
General surgery
11 (52.4)
9 (45)
Pretest
No
12 (57.1)
7 (35)
0.268
Yes
9 (42.9)
13 (65)
A comparative analysis of the groups showed that there was no statistically significant
difference between the groups when the time to tie one knot was compared.
Similarly, there was no statistically significant difference between the groups when
comparing the number of complete knots tied in 10 minutes ([Table 2 ]).
Table 2
Comparative analysis between groups of individuals undergoing monomanual (group A)
and bimanual (group B) laparoscopic suture training
Group
Mean (SD)
Median (range)
p -value
Time it took to tie a complete intracorporeal knot
A
107.0 (43.2)
94.7 (199.3)
0.334
B
118.3 (51.2)
112.7 (223.7)
Time it took to tie 10 consecutive half knots
A
225.5 (91.4)
188.0 (310)
0.020
B
289.7 (99.4)
289.5 (363)
Number of complete knots tied in 10 minutes
A
4.71 (1.74)
n = 99
5 (7)
0.354
B
4.25 (1.94)
n = 85
4 (7)
Numbers of knots that became untied
A
1.43 (1.12)
n = 30
1 (3)
0.448
B
1.15 (0.99)
n = 23
1 (3)
Knot loosening average in millimeters
A
3.27 (1.37)
3.53 (5.5)
0.011
B
2.36 (1.44)
2.1 (6.77)
Force (N) required to open the knots
A
6.5 (4.7)
5.1 (15.2)
0.001
B
11.5 (4.8)
14 (14)
Abbreviations: SD, standard deviation; N, newtons.
The amount of time to tie 10 consecutive knots was shorter in group A than in group
B (225.5 s and 289.7 s respectively; [Table 2 ]).
A statistically significant difference was also identified when comparing the knot
loosening average in mm; group A had an average of 3.27 mm of loosening, and group
B, 2.36 mm. Thus, as a result, the knots made by group B loosened less than those
made by group A ([Table 2 ]), but there was no statistically significant difference between both groups regarding
the number of knots that became untied. The force required to untie the knots was
significantly higher in group B, with a median of 14 N, than in group A, with a median
of 5.1 N ([Table 2 ]).
After the end of the course and evaluation, all participants answered a posttest questionnaire
about the training. All the participants considered the training outcome positive;
36 participants (87.8%) reported a positive change in surgical motivation with the
training, and 40 out of the 41 participants (97.6%) agreed that simulation training
sessions should be part of the resident's curriculum.
Discussion
The results observed in the present study emphasize the importance of training in
the learning curve of surgeons. Prior to the course, 22 participants (53.7%) could
perform an intracorporeal knot in up to 5 minutes, and at the end of the training,
all of them were able to perform it. Among the individuals who tied the knot, in both
groups there was a significant improvement in the amount of time it took them to tie
the knot after training. The average time to perform this exercise in the pre-test
was of 205.25 s, and after the end of the course, the time was halved: 102.4 seconds.
Similarly, after supervised training, the participants who could not tie the knot
in the pretest achieved a result similar to the participants who had tied the knot
in the pretest, thereby confirming the relevance of the training.
A comparative analysis of the groups showed no statistically significant difference
between the groups when comparing the amount of time it took them to tie one knot.
However, when the amount of time taken to tie 10 consecutive knots was compared, group
A was faster than group B. This result may suggest that for operations that require
a greater number of sutures, such as surgery for myomectomy, it would be advantageous
to opt to suture with the dominant hand, tying as much knots as possible in a single
period of time, and taking into consideration the quality of the knots, in order to
avoid unexpected bleeding. Since the time it takes to perform the suturing of the
myometrial defect is described as the main factor that influences intraoperative uterine
bleeding, this is a result of the length of time that the myometrium remains open.
Therefore, the reduction in blood loss depends on a fast and efficient suture, and
this implies that suturing with adequate tension and hemostasis at the time of surgery
is fundamental to the success of the patient's recovery.[18 ]
[19 ]
However, for surgeries that require fewer sutures, suturing with the dominant hand
or with both hands does not make a difference in terms of time in the initial phase
of the learning curve, and this is because continuous practice can make the groups'
time to tie multiple knots match.
No statistically significant difference was observed between the groups regarding
the number of knots that became untied, but the results drew attention to the quality
of the knots that were tied even after supervised training. The number of knots tied
by the dominant hand group and the bimanual group was 184, and, of these, 53 knots
became untied, that is, 28.8% of the sutures were performed with poor quality. The
application of this data in the surgical practice was not evaluated, but there is
a possibility of an increase in intraoperative and postoperative complications.
Another key point observed in the results was the measurement in millimeters of the
knot loosening average, which lead us to affirm that the knots tied bimanually had
loosened less than those tied using the dominant hand alone. In addition, the median
strength in newtons required for the knot to become untied was significantly lower
in the dominant hand group (5.1 N) than in the bimanual group (14 N); therefore, the
knot made with the dominant hand became untied more easily than the knot made with
both hands. The strength needed to break the thread used in our study was of 18 N;
thus, the median force needed to untie the knots of the bimanual group was very close
to the breaking strength of the thread.
It is possible that crossing the instruments to uncross the threads during the suturing
technique with one hand can lead to instability of the square knot if the surgeon
pulls more to one side, that is, if the surgeon does not apply symmetrical forces
at the ends of the thread, as this will compromise the blocking sequence.
In addition, the knot made with both hands was tied by alternating the hands and maintaining
the same direction of the Romeo Gladiator Rule movement. This is another fact that
suggests greater confidence, because unconsciously we choose to perform simple and
repeatable movements that are less difficult. Therefore, maintaining the same direction
ensures that we instinctively maintain the easier direction to perform the movement,
which will be the same as before.
No statistically significant difference was observed between the groups regarding
the number of knots that became untied, but a loosened knot is not as effective, and
can lead to postoperative complications, with different impacts on the health and
recovery of the patient.
The clinical application of this finding was not tested; however, according to practice
and experiences, knot loosening may make sutures ineffective, causing complications
and bleeding. Considering the suture of the vaginal cuff in a total hysterectomy,
if there is some looseness in the suture, not only bleeding may occur, but also dehiscence
of the vaginal cuff in the postoperative period, leading to complications and causing
discomfort to the patient.
The results of the present study confirm the literature findings regarding the efficacy
of the pelvic trainer simulator for the improvement of laparoscopic skills and abilities,[13 ]
[20 ]
[21 ] among them psychomotor control and spatial orientation, which are fundamental for
the practice of laparoscopic suture,[22 ] and also demonstrate the difficulty in achieving such proficiency.
Achieving proficiency in laparoscopic suture is of extreme importance for surgeons,
especially gynecologists, because it is a fundamental step for the most common procedures
in their daily practice, such as hysterectomy and myomectomy.[22 ]
[23 ] The good quality of the suture is fundamental for the success of the postoperative
result, with a lower rate of complications. This is corroborated by studies that demonstrate
a lower rate of surgical complications according to the surgical technique used and
previous training.[23 ]
[24 ]
It is also important to stress that the data herein demonstrated reflects specifically
the studied population in a specific condition of knowledge and training. Although
we personally agree that the bimanual knot tying technique seems safer and may be
faster, it could be true that with a longer training or larger sample size this concept
would change. Another weak point of our study is related to the studied population:
would the results be the same were this study conducted among experts or surgeons
with at least 40 surgeries performed, as required by the Brazilian Federation of Gynecology
and Obstetrics Associations (Febrasgo, in the Portuguese acronym) in order for one
to become a specialist in gynecological endoscopy? Can the experience of a surgeon
correct a tendency to neglect the correct blocking sequence in a monomanual knot tying
procedure?
In the present study, the interference of the studied forms of knot tying (monomanual
or bimanual) in the clinical practice, dealing with living tissue in an actual surgery,
was not tested. In order to complement the data obtained from the present study, the
clinical applicability of these results should be tested. Today we can compare this
study to some literature findings regarding the knot tying time; however, there are
no studies associating the quality of the knots with intra- and postoperative incidents.
Conclusion
In conclusion, the knots from the bimanual group showed better quality than those
from the dominant hand group, with lower loosening measured in millimeters and more
strength required to untie the knots. The group using the dominant hand was faster
than the bimanual group when the amounts of time it took them to tie 10 consecutive
knots were compared. There was no statistically significant difference between the
groups when comparing the amount of time it took to tie one knot. Further studies
will be needed to confirm our findings in other medical communities, and to broaden
the horizons of didactic knowledge in video surgery.
