Some characteristics of technique and early result of video-assisted thoracoscopic surgery for thymoma with myasthenia gravis at 103 Military Hospital

Journal of military pharmaco-medicine no7-2019

SOME CHARACTERISTICS OF TECHNIQUE AND EARLY
RESULT OF VIDEO-ASSISTED THORACOSCOPIC SURGERY
FOR THYMOMA WITH MYASTHENIA GRAVIS
AT 103 MILITARY HOSPITAL
Le Viet Anh1; Nguyen Van Nam1; Nguyen Truong Giang2
SUMMARY
Objectives: To review some characteristics of technique and evaluate the early-result of
video-assisted thoracoscopic surgery for thymoma with myasthenia gravis at 103 Military
Hospital. Subjects and methods: 61 thymoma patients with myasthenia gravis who underwent
video-assisted thoracoscopic surgery thymectomy at 103 Military Hospital, from 10 - 2013 to 5 2019 were included. Results: There were no in-hospital mortality or major postoperative
complications. The mean of operation time was 91.80 ± 49.94 mins, the mean of blood loss was
37.38 ± 31.58 mL, most of the patients resuscitated within 24 hours (93.5%), thoracic drainage
duration was 57.84 ± 30.71 hours, and length of hospital stay was 9.8 ± 5.9 days. Conclusion:
Video-assisted thoracoscopic surgery thymectomy for thymoma had few complications, and was
safe for myasthenia gravis patients.
* Keywords: Thymoma; Video-assisted thoracoscopic surgery; Myasthenia gravis.

INTRODUCTION
Thymoma is a primary tumor in the
upper and anterior mediastinum (90%),
accounting for 5 - 21.7% of all mediastinal
tumors and 47% of all anterior mediastinal
masses, about 0.2 - 1.5% of all malignant
tumor.
Many authors had affirmed that when a
thymoma with myasthenia gravis (MG)
was diagnosed, thymectomy is a first-choice
treatment and most effective. Surgical

removal of thymoma can be carried out
via a trans-sternal or transcervical approach.
Recently, thymectomy via video-assisted
thoracoscopic surgery (VATS) has become
a preferred method for thymoma with
MG at 103 Military Hospital. Therefore,
we carried out this research: To review
some characteristics of technique and
evaluate the early result of video-assisted
thoracoscopic surgery (VATS) for thymoma
with MG at 103 Military Hospital.

1. 103 Military Hospital
2. Vietnam Military Medical University
Correspoding author: Le Viet Anh ()
Date received: 11/07/2019
Date accepted: 23/08/2019

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Journal of military pharmaco-medicine no7-2019
SUBJECTS AND METHODS

In the indispensable cases need a more
trocar to hold the tumor.

1. Subjects.
Sixty-one thymoma patients with MG,
as confirmed by postoperative histology,

who underwent VATS thymectomy at
103 Military Hospital from 10 - 2013 to
5 - 2019, were included.
* Techniques of VATS thymectomy:
- Anaesthetization: With a double-lumen
endotracheal tube for one-lung ventilation.
- Position: A 30 - 45 degree lateral
position.
- Surgical approach: The left or right
VATS was determined according to the
position of the tumor presented in the preoperative chest CT-scan.
- Trocars: VATS was usually carried
out with 3 trocars:
+ Trocar 1: At the 3rd intercostal space
(ICS) (or the 4th intercostal space) in the
anterior axillary (AAL) or mid axillary
(MAL) line for instruments.
th

+ Trocar 2: At the 5 intercostal space
(or the 6th intercostal space) in the anterior
axillary (or mid-axillary) line for the camera.
+ Trocar 3: At the 6th intercostal space
(or the 7th intercostal space) in the anterior
axillary (or mid-clavicular (MCL)) line for
instruments.

- Determination of mediastinal pleura
and anatomical landmarks, removing tumor
and thymus gland. Take the specimen

with a specimen endo-bag under the
camera's observation. Check the surgical
area and put the chest drainage tube.
- Conversion to open surgery when
there were complications which cannot be
treated by VATS, invasive tumors that
VATS could not remove safely.
After surgery, if respiratory is guaranteed,
withdraw the endotracheal tube and transfer
to the Department of Thoracic Surgery or
to the intensive care unit (ICU).
* Index:
- Sites: Sides, number and position of
ports.
- Surgery: VATS or conversion to open
surgery.
- Operating: Status of invasion, accidents,
surgery time, blood loss.
- Postoperative: ICU stay, chest tube
removal time, complications, post-operative
hospital stay.
* Data: with the SPSS software,
version 23.0 (SPSS Inc., Chicago, IL,
USA).

RESULTS
1. Some characteristics of the technique of VATS for thymoma with MG.
Table 1: Sides, number and position of ports.
Criteria

Patients

Rate (%)

Right

35

57.4

Left

26

42.6

3

59

96.7

4

2

3.3

Sites

Number of ports

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Journal of military pharmaco-medicine no7-2019
rd

37

60.7

rd

4

6.6

th

16

26.2

th

4

6.6

th

21

34.4

th

34

55.7

th

3

4.9

th

3

4.9

th

6

9.8

th

52

85.2

th

1

1.6

th

2

3.3

2

3.3

3 ICS - AAL
3 ICS - MAL
Trocar 1

4 ICS - AAL
4 ICS - MAL
5 ICS - AAL
5 ICS - MAL

Position
ports

Trocar 2

of

6 ICS - AAL
6 ICS - MAL
6 ICS - AAL
6 ICS - MAL
Trocar 3

7 ICS - AAL
7 ICS - MCL
Trocar 4

2

nd

ICS - MCL

(ICS: Intercostal space)
There were 35 cases (57.4%) approaching through the right pleural, the remaining
26 cases (42.6%) were approached via left pleural, most patients used 3 trocars
(96.7%) and there were 3 locations commonly used: 3rd ICS AAL (60.7%), 5th ICS MAL
(55.7%) and 6th ICS MCL 85.2%.
Table 2: Relationship between surgery method and tumor size.
Tumor size

Total

Surgery method

< 3 cm

3 - 6 cm

≥ 6 cm

n

15

31

7

53

%

24.6

50.8

11.5

86.9

n

2

4

2

8

p

VATS

Conversion to open surgery

0.68
%

3.3

6.6

3.3

13.1

n

17

35

9

61

%

27.9

57.4

14.8

100

b

Total

(b: Chi - Square test)
Conversion to open surgery was available in all 3 size groups, higher in group
≥ 3 cm. This difference was not statistically significant.
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Journal of military pharmaco-medicine no7-2019
Table 3: Masaoka stage and surgery method.
Masaoka stage

Surgery method
I
VATS
Conversion
surgery

to

open

Total

II

III

Total

IVa

p

IVb

n

34

11

7

1

0

53

%

64.2

20.8

13.2

1.9

0

100

n

1

0

1

6

0

8

%

12.5

0

12.5

75.0

0

100

n

41

12

10

8

0

61

%

57.4

18.0

13.1

11.5

0

100

< 0,001

b

(b: Chi - Square test)
8 cases had to conversion to open surgery, the most were in the group Masaoka Iva
stage, one case in Masaoka I stage, this was the case with operative accident.
Table 4: Characteristics of VATS for thymoma with MG.
Criteria

Patients

Rate (%)

2

3.3

≤ 60

23

37.7

> 60 - 120

27

44.3

> 120

11

18.0

Accidents

Surgical time (minutes)

Mean of surgical time (min) (

Mean of blood loss (mL) (

91.80 ± 49.94

± SD)

37.38 ± 31.58

± SD)

There were 3.3% of complications, the average time of surgery was 91.80 minutes.
23/61 patients (37.7%) within 60 minutes. The average blood loss during surgery:
37.38 mL (at least 10 mL, maximum of 200 mL).
2. The early-result of VATS for thymoma with MG.
Table 5: Early-result of VATS for thymoma with MG.
Criteria

Length of ICU stay (hours)

Chest tube
(hours)

removal

time

Patients

Rate (%)

None

42

68.9

≤ 24

15

24.6

> 24 - 48

2

3.3

> 48

2

3.3

≤ 24

2

3.3

> 24 - 48

40

65.6

> 48

19

31.1

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Journal of military pharmaco-medicine no7-2019
Mean of chest tube removal time (hous) (

57.84 ± 30.71

± SD)

Complications
Postoperative hospital stay
(days)

Mean of postoperative hospital stay (days) (

8

13.1

≤7

28

45.9

8 - 10

21

34.4

> 10

12

19.7

± SD)

9.8 ± 5.9

After surgery, most patients (42/61 = 68.9%) were removed the endotracheal tube
and transferred directly to the Thoracic Department, in ICU within 24 hours (24.6%)
and had time to withdraw drainage after surgery within 48 hours ( 68.9%). The duration
of postoperative treatment was less than 7 days (45.9%) and 8 - 10 days (34.4%) and
the average treatment day was 9.8 ± 5.9 days (the shortest was 5 days, the longest
was 37 days).

DISCUSSION
1. Some characteristics of the
technique of VATS for thymoma with
MG.
The choice of left or right VATS
depends on the surgeon’s experience and
the anatomy of the tumor, which was
normally studied in preoperative chest
CT-scan. While Yim et al (1995) prefered
to approach the tumor via right VATS,
most European surgeons prefer the leftsided approach [1]. In our study, the right
approach was mainly (57.4%). In fact,
right VATS offered better visualization
and control of the superior vena cava,
aorta and right atrium, thereby reducing
the potential risk of injury to these
structures. However, with a non-small
amount of access to the left side of the
road (42.6%), we also had safe operation
with no complications. According to many
opinions of other authors, it is agreed that
the pleural approach to the left or right
side is not different.
138

VATS thymectomy could be accomplished
with 3 ports: A 10 mm port for a
telescope, two ports for instruments, while
the fourth or the fifth trocar could be used
when

necessary.
Some
surgeons
prefered to use four trocars or single-port.
In our study, we managed to completely
remove the thymoma with 3 ports, except
for only two patients (3.3%) with a large
tumor that required another port to hold
the tumor.
The authors' comments that in addition
to patient posture, the position of trocar
plays a very important role in the surgery.
Authors used different trocar position.
Nguyen Cong Minh used 3 trocars at 7th
ICS PAL, AAL and 3rd ICS MAL. Anthony
P.Yim (1999): the 3rd ICS MAL, the 5th
ICS PAL and the 6th ICS AAL. Mineo T.C
(1996) used 4 trocars at the 4th ICS MCL,
the 5th ICS AAL for the camera, the 4th
ICS AAL, the 6th ICS MCL and AAL [2]. In
our study (table 1), we often used 3
trocars: the 3rd ICS AAL (60,7%), the 5th


Journal of military pharmaco-medicine no7-2019
ICS MAL (55.7%) and the 6th ICS MCL
(85.2%). In case of necessity, we used
another trocar at the 2nd ICS MCL.
So far, there is still no agreement on
how big the thymoma’s size is, so it is

possible to work with it, how much should
it not be? The statistics according to table 2
showed that the rate of open surgery was
available in all size groups: size less than
3 cm with two cases, greater than 6 cm
with two cases and from 3 - 6 cm with
4 cases. But this difference was not
statistical significance. Therefore, it can
be seen that the size of the tumor is
relative because it depends on many
other factors, especially the invasion of
the tumor.
It is better when VATS used for
thymoma at early stage (according to
Masaoka). Research was conducted by
Chung et al (2012) on 25 thymoma
patients without myasthenia indicated that
there were no patients in Masaoka stage
III, and only one case in Masaoka stage
IV [3]. Similarly, our data indicated that
there were 8 patients in the Masaoka
stage III (13.1%) and 7 patients in the
Masaoka stage IVa (11.5%), the rest were
in Masaoka stage I, II. Agasthian (2011)
had suggested that thymoma at an early
stage can be safely removed with VATS
[4]. However, the author has reported that
there were 13 patients with invasive
thymoma which could be performed the
surgery successfully. Table 3 showed in

fact that in 8 cases had conversion to
open surgery, most of all in Masaoka IVa
stage, there was only 1 case in Masaoka I
stage due to operation accident. One

point to note was that there was a
difference between the assessment of
the invasive status of thymoma and
surrounding organizations between images
on the CT-scan and in operating. So that
the surgeon had to consider carefully the
characteristics and properties of tumors
on CT-scan before surgery, the direct
assessment of tumors in operating is
extremely important, to be able to predict
the operation and make decisions
immediately to operate with VATS or
conversion to open surgery.
The mean
surgical
time
was
91.80 minutes, we experienced shorter
time surgery in the latter part of the study,
in which 23/61 operations (37.7%) were
completed within 60 mins. The majority of
surgery time was from 60 minutes to
120 minutes (44.3%). This result was
similar to other studies by Yim [1],
Ashleigh Xie [5], Mineo T.C [2] (from

80 minutes to 160 minutes).
The amount of blood loss by the
authors was also different, from 40 mL to
183.1 mL. Blood loss in our study was
37.38 ± 31.58 mL (10 - 200 mL), patients
with high amounts of blood loss were
usually suffered from complications or
conversion to open surgery, while patients
with completely and conveniently VATS,
the amount of blood loss was lower.
2. The early result of VATS for
thymoma with MG.
The results of our study showed that
the time stay at ICU after thymectomy
was reduced with the VATS approach, as
shown by either a smaller number of
patients requiring ICU or shorter length of
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Journal of military pharmaco-medicine no7-2019
ICU stay. In our study, non-ICU: 68.9%; ≤
24 hours: 24.6%; > 24 - 48 hours: 3.3%; >
48 hours 3.3%. Reduced resuscitation
time and ventilation time will reduce the
risk of respiratory failure compared to a
longer time. In comparison with previous
research, it is clear that thymectomy by
VATS had significantly reduced the
duration of postoperative resuscitation

treatment compared to open surgery.
Especially during the later period of the
study, most of our patients were transfered
straightly to the Department of Thoracic
after surgery. It is further demonstrated
that patients had received many advantages
from VATS when performing thymectomy.
According to table 5, the majority of
patients in our study were removed chest
tube after surgery within 48 hours (68.9%).
However, compared with the authors,
there were many different results, the
withdrawal chest tube time was from 1.8
to 4.2 days.
Except for 7 patients (11.5%) with
postoperative respiratory failure and one
patient (1.6%) with a little pleural effusion,
non-hospital mortality or major postoperative
complication was observed in our study,
these results were similar to the study by
Chao (2015), Cheng (2008) [6], Chung
(2012) [3], Liu T.J (2014) [7], Manoly
(2014) [8], Sakamaki (2014) [9] and Ye B
(2014) [10]. No case of diaphragmatic
paralysis as reported by Manoly’s study
(2014) (11.8%) [8], it was 6.7% in Ashleigh
Xie’,s study [5] and pneumothorax in
Ashleigh Xie’s study was 1.9% [5], Ye.B:
0.8% [10].
Most patients had a postoperative

treatment period of fewer than 7 days
140

(45.9%) and 8 - 10 days (34.4%). The
length of postoperative treatment was
9.8 ± 5.9 days (5 - 37 days). The result of
our study was so higher than the other
authors, like Nguyen Cong Minh: 6.5 days
(5 days - 22 days), Anthony P.Yim (1995)
[1]: 5 days, Mineo T.C: 3 days, Mack M.J
(1996): 4 days [12], Popescu I (2002)
[13]: 2.28 days. However, in comparison
with previous open surgery (transternal
surgery), the average postoperative hospital
stay was shortened remarkably.
CONCLUSION
Video-assisted thoracoscopic surgery
thymectomy for thymoma is safe surgery.
It can be widely applied even for MG with
no death, fewer accidents and complications,
good outcomes.
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