Comparison of Three Different New Bipolar Energy Modalities and Classic Bipolar in Vivo for Tissue Thermal Spread
Melike Demir ÇALTEKİN1, Serpil AYDOĞMUŞ2, Serenat Eriş YALÇIN3, Emine DEMİREL2, Fulya CAKALAĞAOĞLU UNAY4, Pelin ÖZÜN ÖZBAY5, Aslı Deniz CEYHAN ÖZDEMİR2, Yakup YALÇIN6, Sefa KELEKÇİ2
1Department of Obstetrics and Gynecology, Malatya Hospital, Malatya, Turkey
2Katip Çelebi University Ataturk Training and Research Hospital, İzmİr, Turkey
3Isparta Obstetrics and Pediatrics Hospital, Isparta, Turkey
4Department of Pathology, Katip Çelebi University Ataturk Training and Research Hospital, İzmİr, Turkey
5Department of Obstetrics and Gynecology, Aydın Obstetrics and Pediatrics Hospital, Aydın, Turkey
6Department of Gynecologic Oncology, Suleyman Demirel University, Faculty of Medicine, Isparta, Turkey
Keywords: Surgery, LigaSure™, Enseal®, Plasmakinetics™, Thermal damage
The aim of this study was to compare three different new bipolar energy modalities and classic bipolar in vivo for tissue thermal
Material and Method: This prospective, randomized, single-blind study was conducted between Septemsber 2012 and July 2013. Eighteen
patients aged 40-65 years undergoing hysterectomy and bilateral salpingectomy for benign etiology were included in the study. Before the
hysterectomy operation began, it was marked nearly distal third cm started from uterine corn and proximal close third cm started from fimbrial
bottoms by visualizing both fallopian tubes. The surgery was performed using one 5 mm applicator of PlasmaKinetics™, EnSeal®, LigaSure™ or
classic bipolar energy modality. The time each device was used was standardized as the minimum time of the audible warning of the device
for tissue impedance and as tissue vaporization on classic bipolar. Tissues were dyed by both H&E and Masson's Trichrome in the pathology
laboratory. Thermal spread was compared.
Results: Evaluation of the damage on the uterine tubes by each device used revealed that LigaSure™ was associated with increased thermal injury
compared to PlasmaKinetics™ (p=0.007). Apart from PlasmaKineticsTM (p=0.022), there was no statistically significant difference between the
three devices in terms of thermal damage spread in the distal and proximal fallopian tubes.
Conclusion: To reduce lateral thermal damage, Plasmakinetics™ may be preferable to Ligasure™ among the three different new bipolar energy
Energy-based devices are nowadays being used widely in
open and laparoscopic surgeries for dissection, cauterization
and vessel-sealing purposes. Electrosurgery refers
to the use of high frequency electric current for tissue
cutting and coagulation processes1
. Since the discovery
of electrosurgery in the modern era, various modalities of
energy with dissection, cauterization and sealing properties
have been produced particularly in laparoscopic surgery.
However, despite the advantages of these devices, surgeons
are faced with the risk of tissue damage due to peripheral
Various systems dependent on bipolar energy are being
used on tissues and vessels in laparoscopic surgery2,3.
LigaSure™ fuses collagen and elastin in the vessel wall by applying a certain amount of bipolar energy and pressure.
Heat desorption to adjacent tissues is approximately 2
mm4,5. PlasmaKinetics™ conducts system-pulse bipolar
energy to tissues via the device allowing discontinuous tissue
cooling which in turn restrains lateral heat desorption and
tissue adhesion6. In the system, high energy is conducted
to the grasped tissue creating vapor zones. The current
proceeds through highly resistant vapor zones via the least
resistant pathway. Vapor zones collapse sequentially and
with every new pulse of energy more tissue is coagulated
between the tips of the device; consequently, the tissue is
coagulated homogenously7. EnSeal® ensures sealing
of the tissue by combining energy control of the bipolar
sealing device with a compression mechanism. Thermal
desorption is approximately 1 mm8.
The widespread use of electrosurgery in time will increase
the effectiveness and minimize the risks of the devices.
Our study aimed to compare the classic bipolar and three
new bipolar energy modalities in terms of lateral thermal
propagation in the uterine tubes.
This prospective, randomized, single-blind study was
conducted between September 2012 and July 2013 at the
Clinic of Obstetrics and Gynecology of Izmir Katip Çelebi
University Ataturk Training and Research Hospital. The
study was approved by the Ethics Committee of Izmir Katip
Çelebi University and the local academic board (2012-
37). It was consistent with the Declaration of Helsinki for
Medical Research Involving human subjects. Informed
consent was obtained from all patients.
Eighteen patients aged 40-65 years undergoing hysterectomy
and bilateral salpingectomy of benign etiology were
included in the study. Patients with previous abdominal
surgery, endometriosis, hydrosalpinx or tubal adhesions
were excluded. Patients diagnosed with malignancy,
endometriosis or hydrosalpinx during frozen sections or
postoperative pathologic assessment were also excluded
from the study.
Both uterine tubes were visualized and marked proximally
3 cm from the uterine horn, distally 3 cm from the fimbrial
end before the hysterectomy operation. Energy was applied
with 5 mm wide applicators of each modality. One modality
was applied both on the distal and proximal segments of
the right uterine tube, and a different modality was applied
on the distal and proximal segments of the left uterine
tube. Classic bipolar cautery was evaluated as the control
group. Application time of each device was standardized
as the minimum time needed for an audible warning
signal according to the tissue impedance. In the classic
bipolar without an audible warning signal, the process
was terminated after visualizing tissue vapor. Ultimately
uterine tubes were excised by sharp dissection, marked
for applicator treated areas and sent to the pathology
laboratory (Figure 1). The uterine tubes were fixed in
formalin, defined macroscopically and sampled. 3-5 micron
thick sections were obtained from paraffin blocks of the
uterine tube samples. H&E and Masson's trichrome (MT)
stained sections were evaluated by a single pathologist;
areas of damaged or necrotic tissue were morphometrically
assessed and compared under light microscopy (Leica
DM 4000 B, Leica-Software). The pathologist was blinded
to the energy modality used. The incision made by the
applicator was considered as the demarcation line; the amount of inflammatory response, tissue congestion,
fibrosis and coagulation necrosis formed laterally from this
line was recorded and the distance from normal tissue was
measured (Figure 2,3).
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|Figure 2: Normal tubal view on the left and coagulation necrosis
due to thermal damage on the right (H&E; x10).
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|Figure 3: The red coloured area marked with a square indicates
thermal damage. The black line is used to measure the propagation
of the thermal damage (Masson’s Trichrome; x10).
A total of 72 specimens from 18 patients, applying two
different energy modalities on each patient, were evaluated.
Each energy modality was compared with other modalities
in 3 patients, corresponding to 12 samples (Figure 4).
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|Figure 4: The chart of patient groups
according to the use of the devices.
Data were analyzed by the IBM SPSS 22.0 software (SPSS
Inc., IBM, Chicago, IL, USA), and descriptive data were
expressed as mean±standard deviations (SDs), median
and range. The distribution of variables was assessed by
the Kolmogorov-Smirnov test. The effect of the device and
uterine tubes on thermal damage propagation was evaluated
by generalized estimating equations (GEE) model. p < 0.05
was considered significant in all analyses.
The mean age, gravidity and parity of the patients included
in the study were 48.4 ± 5.8, 2.8 ± 1.3 and 2.1 ± 1.02
respectively. 16 patients were in the premenopausal and 2
patients were in the postmenopausal period. Indications
and type of the surgery performed are listed in Table I
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|Table I: Distribution of patient age, gravidity, parity, menopausal status, indications for hysterectomy and the type of surgery performed
Values for spread diffusion of lateral thermal damage on
the distal uterine tube tissue in terms of energy modalities
applied are 2128 ± 1116 μm, 1671 ± 435 μm, 1721 ± 945
μm, 1310 ± 445 μm for LigaSure™, Enseal®, classic bipolar,
and Plasmakinetics™ respectively. Values for propagation
of lateral thermal damage on the proximal uterine tube
tissue in terms of energy modalities applied are 2294 ± 693
μm, 1860 ± 858 μm, 1934 ± 604 μm, 1898 ± 474 μm for
LigaSure™, Enseal®, classic bipolar, and Plasmakinetics™
respectively (Table II).
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|Table II: Comparison of the results of thermal damage propagation (μm) in terms of the devices applied on distal and proximal uterine tubes
When the thermal damage on distal and proximal uterine
tubes caused by the devices used was considered, values
for propagation of the lateral thermal damage (μm) on
the distal uterine tube in Plasmakinetics™ applied cases were found to be significantly lower than the values for the
proximal uterine tube (p<0.05) (Table II). Although there
was no significant difference between distal and proximal
uterine tubes in terms of dissemination of the lateral
thermal damage in Ligasure™, Enseal®, and classic bipolar
applied cases, dissemination of the lateral thermal damage
on the distal segments was found to be clinically lower than
on the proximal segments.
While analysing the damage on uterine tubes by each
devices used, Ligasure™ was associated with increased
thermal injury compared to Plasmakinetics™ (p=0.007)
(Table III). When other pathologic parameters such as
congestion, necrosis and fibrosis were analyzed by device,
there were no statistically significant differences between
the groups (p> 0.05).
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|Table III: Comparison of the damage on uterine tubes caused
by the devices used
In our study, three new bipolar energy modalities and
the classic bipolar energy modality have been compared
in terms of the risks they pose. Studies on thermal tissue
damage related to variable energy modalities have been
recently gaining importance in the literature. To our
knowledge, there are no reported studies to date comparing
four different bipolar energy modalities on the same tissue.
In a study of Carbonell et al. in which thermal damage
propagations of PlasmaKinetics™ and LigaSure™ on vessels
were investigated, thermal damage on the vessels was found
to be equal and the damage in greater vessels was found
to be wider9. Unlike this study, our study demonstrated
that Ligasure™ was associated with increased thermal injury
compared to Plasmakinetics™.
Sahin et al. reported that the thermal tissue damage and
inflammatory response caused by EnSeal® was lower than
that of LigaSure™ in a study comparing the thermal damage
and inflammatory responses of EnSeal ® and LigaSure ™ on
the liver10. Although not statistically significant, thermal damage propagation of EnSeal® in our study was slightly
lower than that of LigaSure™.
In another study, monopolar, harmonic (Pov 3), harmonic
(Pov 4) and LigaSure™ were compared. Thermal damage
propagation of LigaSure™ was measured to be 144.18 μm11. In Goldstein's study on pig ureters, the approximate
thermal damage propagation of LigaSure™ was 2110 μm3. Different studies about the same energy modality
yielding different results could be explained by variable
tissue thicknesses, tissue perfusion and the variability
of the energy applied by the device in response to tissue
Considering the lateral thermal damage propagations of
each device on distal and proximal tubal segments in our
study, the least-damaging device on the distal uterine tube
was PlasmaKinetics™ whereas the most-damaging device
was LigaSure™. Assessing the lateral thermal damage
propagation on the proximal uterine tube, the propagation
caused by PlasmaKinetics™ increased significantly with
tissue thickness. This finding could be linked to the
variability of tissue impedance related to the difference of
muscular intensity in the distal and proximal segments of
the uterine tube. However, this trend was not observed in
other bipolar energy modalities.
The strength of our study is the comparison of four different
devices, all using bipolar energy modalities, on variable
thicknesses of the same tissue. To our knowledge, there are
no reported studies in the literature comparing these four
bipolar energy modalities. Moreover, the comparison of
the effects of different energy modalities on the same tissue
was enabled by using both tubes of the same person; and
the evaluation of the impact of tissue impedance on tissue
response created by the energy modalities was enabled by
using different thicknesses of the same tube. Propagation of
thermal injury could be observed more clearly in our study
by using the H&E and the MT stains. Furthermore, only a few of the studies on this topic have been conducted on
living human tissue, the rest being conducted on animals.
A limitation of our study is that the pathology specimens
were examined under light microscopy. Pathological
alterations in cell damage occur only during the third stage.
Therefore, more comprehensive studies are needed to
examine the early biochemical and ultrastructural changes
thoroughly. In addition, the thermal damage propagation
in our study was measured laterally but not vertically; the
latter was rendered impossible by the presence of a tissue
with a different structure, the peritoneum, under the
Considering the recent advances in surgical energy
modalities, nowadays the intention is to increase the
effectiveness and minimize the risks of the devices. Herein,
we found that Ligasure™ was associated with increased
thermal injury on living human uterine tubes' segments
compared to Plasmakinetics™ and that Plasmakinetics™
may be preferable to reduce the lateral thermal damage.
Energy modalities used on human tissues necessitate
clinical studies including larger series.
CONFLICT of INTEREST
The authors have no conflicts of interest to disclose.
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