Nghiên cứu ứng dụng phẫu thuật nội soi lồng ngực điều trị u tuyến ức có nhược cơ tại bệnh viện quân y 103 tt tiếng anh

MINISTRY OF EDUCATION

MINISTRY OF

AND TRAINING

NATIONAL DEFENCE

VIETNAM MILITARY MEDICAL UNIVERSITY

LE VIET ANH

STUDY ON APPLICATION OF
VIDEO-ASSISTED THORACOSCOPIC SURGERY FOR
THYMOMA WITH MYASTHENIA GRAVIS
AT MILITARY HOSPITAL 103
Specialized: Surgery
Code: 9720104

SUMMARY OF DOCTORAL THESIS

HANOI – 2019


THE STUDY ARE COMPLETED AT
VIETNAM MILITARY MEDICAL UNIVERSITY
Scientific Supervisor:
Assoc. Prof. Nguyen Truong Giang, MD, PhD
Assoc. Prof. Nguyen Van Nam, MD, PhD

Reviewer 1: Assoc. Prof., MD, PhD

Reviewer 2: Assoc. Prof., MD, PhD
Reviewer 3: Assoc. Prof., MD, PhD

The Thesis will be presented at the Military Medical
Academy
At the time:……./…..…/20......

This thesis can be found at:
1.

The National Library

2.

Military Medical University Library

3.

………………………………….


1

ABBREVIATIONS
1

AAL

Anterior axillary line

2

CSR

Chemical shift ratio

3

CT

Computed tomography

4

MRI

Magnetic resonance imaging

5

MAL

Mid-axillary line

6

MCL

Midclavicular line

7

MG

Myasthenia Gravis

8

ICU

Intensive care unit

9

ICS

Intercostal space

10

VATS

video-assisted thoracoscopic surgery
INTRODUCTION

Thymoma is a rare epithelial tumor of the thymus but the most
common mediastinal tumor in adults, accounting for 15% -21.7% of
mediastinal tumors and 47% of anterior mediastinum tumors, about
0.2% -1.5% of all malignant tumors.
Research by Strollo DC (1997) shows that thymoma is

common in adults, Myasthenia Gravis (MG) occurs in approximately
30% to 50% of patients with thymoma. In comparison, only 15% of
patients with MG have a thymoma. MG is also known as an
autoimmune disease that is related to the thymus's activity and
pathological disorders.
The diagnosis of thymoma with MG plays an important role.
There are many diagnostic methods, the most common is chest
computerized tomography (CT) and magnetic resonance imaging
(MRI).


2
Many authors have affirmed that when a thymoma with MG
was a diagnosis, thymectomy is a first-choice treatment and most
effective. However, the results also depend on many factors such as
pre-operative

patient's

status,

surgical

method,

postoperative

treatment…
Up to date, there are many methods for surgery to remove
thymoma

and

thymus,

such

as

trans-sternal,

transcervical,

thoracotomy approach, especially Minimal invasive surgery: videoassisted thoracoscopic surgery (VATS). The surgery requirement is to
remove all of the thymoma, the thymus, and the mediastinal fat.
The choice of surgical method is extremely important.
Classic trans-sternal surgery causes much chest damage with severe
pain, easily affected by respiratory function, or having sternities
complications. Transcervical surgery is difficult to remove all the
thymoma and thymus gland, especially in cases of thymoma and
thymus enlargement, located at the lower pole. The VATS is
considered by many authors to have many advantages: less pain, less
impact on respiration, early recovery.
With many years of treatment of MG, thymoma, and more
than 10 years of experience in VATS, Department of Thoracic
Surgery - Military Hospital 103 has made initial success in treatment
thymoma with MG by VATS. However, the question is whether the
VATS for treating thymoma with MG will completely remove
thymoma, thymus and mediastinal fat as well as open surgery and
how is the result of that treatment method.

It is necessary to have a research and systematic evaluation
of the application of VATS for the treatment of thymoma with MG.


3
Therefore, stemming from practical demands mentioned
above, we carried out the thesis: "Study on application of videoassisted thoracoscopic surgery for thymoma with Myasthenia
Gravis at Military Hospital 103" with two purposes:
1. Review

some

clinical,

imaging

and

histopathological

characteristics of thymoma with Myasthenia Gravis performed
by VATS.
2. Evaluate results of VATS for thymoma with Myasthenia Gravis
at Military Hospital 103.
The new contributions of the thesis are as follow:
The thesis has described some clinical features of thymoma with
MG at Military Hospital 103 by VATS in patients age from 21-70,
duration of the disease is less than 1 year, MG class I and IIA.
The

thesis

has

described

some

features

of

imaging,

histopathology of thymoma with myasthenia gravis at Military
Hospital 103 with CT imaging: thymoma are located in every position,
round or oval shape, the high degree of enhancement and level of drug
absorbed. On MRI: round and oval shape; smooth border or lobes;
with fiber capsulate, CSR = 1.04 ± 0.17. Histopathology: met all types,
most of them are type AB and B2 (29.5%), none of the thymus
carcinoma; the largest size is type B2 and the smallest size is type A.
The thesis has shown that the effectiveness of VATS for
treatment thymoma with myasthenia gravis at Military Hospital 103
with a complete cure rate and improved after surgery increases with
follow-up time: 1 month: 85.3%, 6 months: 87.9%,> 1 year: 94.3%.
The composition of the thesis:
The thesis has 132 pages. Introduction: 2 pages; Overview: 32
pages; Objects and methods: 27 pages; Results: 32 pages; Discussion: 36

4
pages; Conclusion: 02 pages; Recommendation: 01 page. 136 references:
21 Vietnamese references and 115 English references.
CHAPTER 1: OVERVIEW
1.2. Characteristics of clinical, paraclinical of thymoma with
Myasthenia Gravis
1.2.1. Clinical of thymoma with Myasthenia Gravis
1.2.1.1. Symptoms
* Thymoma: from asymptomatic to nonspecific signs such as
anorexia, weight loss, chest pain, shortness of breath, cough ...
especially associated with MG.
* MG: MG symptoms change during the day (heavier in the morning,
the rest is better, the more active is heavier).
1.2.1.3. The diagnosis of myasthenia gravis
+ Test Tensilon (Edrophonium) or Prostigmin
+ Test Jolly
1.2.2. Paraclinical of thymoma with Myasthenia Gravis
1.2.2.4. Chest CT
Chest CT can easily identify not only thymoma but also
normal thymus
On chest CT, we can see the following signs:
- Spherical or multi-lobed
- The density of gland is equal or exceeds muscle of chest wall
- Including fat
- Calcification in the mass
- One-sided development or at the middle line.
1.2.2.6. MRI
CHT is a new modern technique applied in the diagnosis of

5
thymus and thymoma. The authors calculated the chemical shift ratio
(CSR - chemical shift ratio). CSR is statistically significant in
distinguishing thymoma from normal thymus or hyperplasia
1.2.3. Staging of MG and thymoma
* MG staging MG of Perlo-Osserman classification - 1979
+ Class I: ocular involvement only.
+ Class IIA: mid generalized MG: generalized muscle involvement
but no pulmonary involvement.
+ Class IIB: moderately generalized MG: bulbar manifestations.
+ Class III: rapid progression of generalized bulbar disease and
weakening of breathing muscle.
+ Class IV: late severe MG: like class III but progressive symptoms
in many years.
* Thymoma staging of Masaoka
+ Stage I: Grossly and microscopically completely encapsulated
tumor
+ Stage II: Macroscopic invasion into thymic or surrounding fatty
tissue, or mediastinal pleura or pericardium and microscopic transcapsular invasion
+ Stage III: Macroscopic invasion into neighboring organs:
pericardium, great blood vessels, or lung
+ Stage IV:
- IVa: Pleural or pericardial metastases
- IVb: Lymphogenous or hematogenous metastasis
1.3. Surgery method for thymoma with myasthenia gravis
The basic purpose of VATS for thymoma with MG is to
remove all of the thymoma, the thymus, and the mediastinal fat


6

1.3.2. Surgery methods
1.3.2.1. Open surgery
+ Trans-sternal approach
+ Thoracotomy approach
1.3.2.2. Video-assisted transcervical approach
1.3.2.3. VATS for thymoma with MG
First described by Sugarbaker in 1993
In Vietnam, the first case of VATS for MG was performed at Cho Ray
Hospital in 2004. Military Hospital 103 was performed in 9/2008.
CHAPTER 2: OBJECTS AND METHODS
2.1. Objects
Sixty-one patients thymoma with MG, as confirmed by
postoperative histology, who underwent by VATS in Department of
Thoracic Surgery - Military Hospital 103, Vietnam from 10/2013 to
5/2019 were included.
2.1.1. Selection criteria
+ Patients diagnosed before surgery: thymoma with MG.
+ MG class I and IIA.
+ Treatment by VATS for thymoma and thymectomy.
+ Having histopathological results post-surgery to confirm thymoma.
+ No age limit, regardless of gender.
+ Patients and their families were clearly explained about the disease,
VATS and voluntary participation in research.
+ There are sufficient medical records (the medical records must
meet the requirements of the study).
2.1.2. Exclusion criteria
+ Recurrent thymoma.


7

+ No indication for VATS: thymoma after radiotherapy, invasion into
large blood vessels, lung hilum, trachea.
+ Loss or incomplete medical records according to research
requirements.
2.2. Methods
2.2.1. Study design: intervention, no comparison, and prospective
descriptive study, convenient sample size.
2.2.2. Research facilities
Chest endoscopy system, Electric cautherization system,
harmonic scalpal, Automatic cutting-stitching tool, Trocards for
VATS, Other endoscopic tools.
2.2.3. Surgical procedure
2.2.3.1. Indication
+ MG class I, IIA.
+ Thymoma: size < 10 cm, non-invasive into great vessels, lung
hilum, trachea.
2.2.3.2. Pre-operative
* MG diagnosis:
+ Ptosis, muscle weakness changes during the day
+ Test Prostigmin: positive
+ Electromyography: positive
* Pre-operative medical treatment:
+ Checking, preventing and treating the infection.
+ Raising MG class, stabilizing MG condition.
* Explain carefully to patients and families.
2.2.3.3. Techniques of VATS thymectomy
* Anaesthetize: with a double-lumen endotracheal tube
* Position: 30-45 degree lateral position.

8
* Surgery technique::
Follow rules:
- VATS, if not successful, can be converted to supportedVATS, small mamary incision or conversion to open surgery.
- Remove the entire thymic tumor, thymus gland, and
mediastinal fat from under the pericardium to the base of the
neck, between the right and left diaphragm nerves.
- Surgical approach: via the left or right pleural cavity was
determined according to the position of the thymoma presented in the
pre-operative diagnosis by chest CT, use 3 trocards.
- Determination of mediastinal pleura and anatomical landmarks;
removal of thymic tumors and thymus gland.
- Take the specimen with a specimen endo-bag under the camera's
observation.
- Re-check the surgical area and remove the VATS instruments.
2.4.4. Post-operative treatment
- After surgery, withdraw the endotracheal tube and transfer to the
Department of Thoracic Surgery or the intensive care unit (ICU).
- Monitor the chest tube drainage.
- Continue medicine treatment for MG.
- Post-operative X-ray.
-Chest tube extubation: lung expands well, no pneumothorax, pleural
effusion < 100ml/24h.
- Re-examine by X-ray after the chest tube drainage extubation.
- Checking the surgical wounds.
- Monitor and manage postoperative complications
- Combined treatments after surgery.


9

2.2.5. Monitor and evaluate the long-term results
* Monitor: 1 month, 6 months and over 1 year post-surgery.
* Basis for evaluating results:
+ The progression of symptoms of MG, demand for medication after
surgery.
+ Tumor recurrence: by chest CT.
+ Working quality of patients after surgery.
+ Quality of life after surgery.
* Methods of monitoring:
+ Direct examination.
+ Phone, use post-surgery test slip sent to each patient.
+ Receiving chest CT scan results from the patients.
2.2.6. Research criteria
2.2.6.1. Clinical criteria
* General characteristics of the patient: age, gender
* Clinical symptoms
- Classification of myasthenia gravis: Class I, IIA, IIB, III and IV.
2.2.6.2. Paraclinical criteria
* Chest CT: location, size, contour of the tumor, density, infiltration,
calcification, necrosis, invasion.
* MRI: shape, border, fiber encapsulation, fibrous septum, invasion,
size, CSR.
2.2.6.3. Operative criteria
- Sites, number of ports, the position of the port.
- Surgey method: VATS and conversion to open surgery
- Operative evaluations: the number and position of the tumor, tumor
size, the status and extent of the invasion, complications, surgical
time, volume of blood lost.

10

2.2.6.4. Post-Operative criteria
- Length of ICU stay.
- Chest tube removal time.
- Complications after surgery.
- Post-operative hospital stay.
- Histopathological results:
+ According to WHO in 2004
+ Determining the invasion status according to Masaoka’s staging.
2.2.6.5. Indicators for long term monitoring after surgery
+ Assessing the recurrence tumor status: by CT.
+ Assessing the improvement of MG: complete stable remission,
improved, unchanged, worse, died of MG.
2.2.7. Statistical analysis
Statistical data were analyzed using SPSS version 23.0
CHAPTER 3: RESULTS
3.1. General characteristics of the research subjects
- The average age of the patients was 47,31 ± 10,87 years.

-

Female/male ratio = 0,91.

- Duration of disease was less than 1 years: 82%
3.2. Characteristics of clinical, imaging and histopathology of
thymoma with MG performed by VATS.
Table 3.6. MG status before surgery
MG status

Patients

Rate (%)

Class I

12

19,7

Class IIA

49

80,3

Total

61

100

Class IIA accounted for the highest rate (80,3%).


11
Table 3.10. Characteristics of thymoma on chest CT
Characteristics

Patients

Rate (%)

Right

21

34,4

Left

17

27,9

Centre

23

37,7

< 3 cm

17

27,9

3-6 cm

35

57,4

≥ 6 cm

9

14,7

Round

35

57,4

Oval

23

37,7

Plaque

3

4,9

Smooth

42

68,9

Irregular

19

31,1

Low

0

0

Medium

43

70,5

High

18

29,5

The extent of

Less

5

8,2

contrast

Medium

26

42,6

absorption

Much

30

49,2

Yes

4

6,6

No

57

93,4

Yes

16

26,2

No

45

73,8

Yes

1

1,6

No

60

98,4

Position

Size

Shape

Coutour
Degree of
enhancement

Calcification
Invasion
Necrosis

Table 3.11. Characteristics of thymoma on MRI


12
Patient

Characteristics

Rate (%)

(n = 27)

Round, oval

24

88,9

Other

3

11,1

Smooth

15

55,6

Lobular

12

44,4

Fiber

Yes

24

88,9

encapsulate

No

3

11,1

Yes

14

51,9

No

13

48,1

Yes

5

18,5

No

22

81,5

Shape
Contour

Fiber septum
Invasion
Size

Length (mm)

35,30 ± 13,92

Width (mm)

23,93 ± 13,39

CSR= 1,04 ± 0,17
Table 3.12. Histopathology and size of thymoma on chest CT
Mean largest diameter

Type

Patients

Rate (%)

A

11

18

33,73 ± 11,94

AB

18

29,5

39,94 ± 21,16

B1

13

21,3

41,00 ± 17,50

B2

18

29,5

46,22 ± 19,37

B3

1

1,7

37

Total

61

100

40,85  18,34

(mm) (  SD)

3.3. Results of VATS for thymoma with MG at Military Hospital
103
3.3.2. Characteristics of technique of VATS for thymoma with MG


13

Table 3.24. Access to mediastinum via pleural cavity
Access to mediastinum

Patients

Rate (%)

Right pleural cavity

35

57,4

Left pleural cavity

26

42,6

Total

61

100

Table 3.25. Number of trocards
Trocards

Patients

Rate (%)

3

59

96,7

4

2

3,3

Total

61

100

Table 3.26. Position of ports
Position of ports

Patients

Rate (%)

ICS 3 - AAL

37

60,7

Trocard

ICS 3 – MAL

4

6,6

1

ICS 4 – AAL

16

26,2

ICS 4 - MAL

4

6,6

ICS 5 – AAL

21

34,4

Trocard

ICS 5 - MAL

34

55,7

2

ICS 6 – AAL

3

4,9

ICS 6 - MAL

3

4,9

ICS 6 – AAL

6

9,8

Trocard

ICS 6 – MCL

52

85,2

3

ICS 7 – AAL

1

1,6

ICS 7 – MCL

2

3,3

ICS 2 - MCL

2

3,3

Trocard


14
4

Table 3.31. Surgery method in relation of Masaoka’s staging
Masaoka’s staging

Surgery method

Total

I

II

III

IVa

n

34

11

7

1

53

%

64,2

20,8

13,2

1,9

100

Conversion to

n

1

0

1

6

8

open surgery

%

12,5

0

12,5

75,0

100

n

41

12

10

8

61

%

57,4

18,0

13,1

11,5

100

VATS

Total

p

< 0,001b

3.3.3. Efficacy of VATS for thymoma with MG
Table 3.33. Surgical time
Surgical time (minutes)

Patients

Rate (%)

≤ 60

23

37,7

> 60 - 120

27

44,3

> 120

11

18,0

Total

61

100

Mean surgical time (min) (

 SD)

91,80  49,94

Mean blood loss volume (ml) (  SD)

37,38  31,58

Table 3.37. Length of ICU
Length of ICU stay

Corrected

Patients

Rate (%)

None

42

68,9

68,9

≤ 24

15

24,6

93,5

> 24 – 48

2

3,3

96,8

(hours)

rate (%)


15
> 48

2

3,3

Total

61

100

100

≤ 24 giờ (93,5%)
Table 3.38. Chest tube removal time
Chest tube removal time

Corrected rate

Patients

Rate (%)

≤ 24

2

3,3

3,3

> 24 – 48

40

65,6

68,9

> 48

19

31,1

100

Total

61

100

(hours)

(%)

Mean of chest tube removal time (hours)
(  SD): 57,84  30,71
≤ 48 giờ: 68,9%
Table 3.39. Complications
Complications

Patients

Rate (%)

Respiratory distress

7

11,5

Pleural effusion

1

1,6

Total

8

13,1

Table 3.40. Postoperative hospital stay (days)
Postoperative hospital

Cumulative

Patients

Rate (%)

≤7

28

45,9

45,9

8 – 10

21

34,4

80,3

> 10

12

19,7

100

Total

61

100

stay (days)

rate (%)

Mean of Postoperative hospital stay (days) (  SD): 9,8  5,9
3.3.4. Results VATS for thymoma with MG


16

Table 3.41. Change the MG status at times
Monitor time

MG status after surgery

After

After

After

surgery:

surgery:

surgery:

1 month

6 month

> 1 year

(n=61)

(n=58)

(n=53)

n

%

n

%

n

%

Complete stable remission

7

11,5

9

15,5

12

22,6

Improved

45

73,8

72,4

38

71,7

Unchanged

9

14,8

7

12,1

3

5,7

Worse

0

0

0

0

0

0

Died of MG

0

0

0

0

0

0

4
2

The longer the monitoring period, the higher the complete stable

remission and improved rate.
Table 3.42. Recurrence tumor after surgery at times
Follow time

Recurrence tumor

After

After

surgery

surgery

1 month

6 month

(n=61)

(n=58)

After surgery
Over 1 year
(n=53)

n

%

n

%

n

%

Recurrence

0

0

0

0

2

3,8

None

61

100

58

100

51

96,2


17
Total

61

100

58

100

53

100

02 recurrence tumor after surgery over 1 year.

CHAPTER 4: DISCUSSION
4.2. Characteristics of clinical, imaging and histopathology of
thymoma with Myasthenia Gravis which performed by VATS
4.2.1. Characteristics of clinical of thymoma with MG which
performed by VATS
The most common symptom is ptosis (71,2%). There were

one or more clinical symptoms in one patient.
* MG status of thymoma patient
There were 80.3% of MG class IIA. Patients in class IIB or
higher levels were not indicated for surgery because there were
many complications after surgery, especially respiratory failure.
4.2.2. Imaging of thymoma with MG which performed by VATS
4.2.2.1. Characteristics of thymoma with MG on chest CT
* Tumor location: thymus tumors were found in any location. Tumor
located in different locations was found by McErlean. In this study,
thymoma was located in all positions, left site: 27.9%, right site:
34.4% and in the central position was 37.7%.
* Tumor size: 85% of the tumors are under 6 cm, most tumors are
from 3-6cm: 57.4%.
* Tumor shape: round and oval are common (95.1%)
* Tumor contour: smooth and irregular were 68.9% and 31.1%,
respectively.
* Tumor density: medium or high level.


18
* Extent of contrast absorption: the degree of contrast absorption
more or less reflects the level of malignancy. We only had 5 cases
(8.2%) with low contrast absorption. According to Pham Huu Lu,
there is no relationship between the degree of contrast absorption and
the malignant properties of thymoma.
* Calcification, invasion and necrosis of tumors: the rate of invasion
observed on CT was quite high, up to 26.2%, meanwhile the rate of
calcification and necrosis is low (6.6% and 1.6 %).
4.2.2.2. Characteristics of thymoma with MG on MRI
* Shape of the thymoma on MRI

There were 24/27 thymoma cases (88.9%) were round or
oval, 15 were smooth (55.6%). Mai Van Vien's study on 188
operated-patients with MG, there was one case of thymus carcinoma.
In this study, there were 24 thymoma cases (88.9%) with partial or
complete fibrous encapsulation. There were 13 tumors (48.1%) with
fibrous septa. The thymic tumor has a mean size of 35.30 ± 13.92mm
in length, 23.93 ± 13.39mm in width.
* CSR index: The average CSR was 1.04 ± 0.17. Phung Anh Tuan
concluded that CSR values can be used to distinguish between
thymoma and non-thymoma cases. The authors Inaoka T, Popa G,
Priola AM found that the difference of CSR between hyperplastic
patients and thymoma patients was statistically significant with p
<0.001.
4.2.3. Histopathology of thymoma with MG performed by VATS
Type AB and type B2 type were the highest rates (29.5%),
with no thymic carcinoma. The type B2 has the largest size (46,22 ±
19,37 mm), the smallest size was in type A (33,73 ± 11,94 mm).


19
There is no difference between the sizes of thymic tumor
types. Therefore, the size of the thymoma has little prognostic value.
4.3. Results of VATS for treating thymoma with MG at Military
Hospital 103
4.3.2. Characteristics of VATS technique treating for thymoma with
MG
* Access to the mediastinum via the pleural cavity
The choice of left or right pleural cavity for VATS depends
on the surgeon’s experience and the anatomical characteristics of the
thymoma, which was studied in preoperative chest CT scans. In our

study, the right approach is dominant (57.4%). In fact, right pleural
cavity 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. The authors agreed that the approach via
the left or right pleural cavity is not different.
* Number of ports
Classic use of 3 trocards is often observed, some use 4 or
uniport-VATS. We follow the classic technique of using 3 trocards
and found that we can easily remove the entire thymus gland and
thymoma, only 02 cases (3.3%) used an additional 4th trocar due to
the big size of the tumor.
* Position of the trocar
The authors' comments that in addition to patient posture, the
position of trocards plays a very important role in the surgery.
Different authors use different trocard position. we often used 3
trocards: 3rd ICS AAL (60,7%), 5th ICS MAL (55,7%) and 6th ICS
MCL (85,2%). In case of necessity we use another trocard at 2nd


20
ICS MCL. With 86.9% cases of successful VATS proved that the
position of trocards was reasonable.
4.3.3. Efficacy of VATS for thymoma with MG
* Surgical time: average surgical time was 91.8 minutes. There were
23/61 cases (37.7%) with the surgical time fewer than 60 minutes.
This result was similar to the other authors from 80 minutes to 160
minutes: Yim, Popescu, Ashleigh Xie, Mineo T.C.
* The blood volume lost during operation: in general, the blood loss
in VATS was less than open surgery. The other authors: from 40 ml
to 183.1ml. Our results were about 37.38  31.58ml.

* Complications
There were no deaths, similar to the authors: Chao, Cheng,
Chung, Liu TJ, Manoly, Sakamakiv and Ye B; respiratory failure after
surgery: 7 (11.5%); pleural effusion: 1 (1.6%).
- 7 cases (11.5%) experienced respiratory disstress after surgery,
support ventilation and plasmapheresis therapy are needed.
- 1 case (1.6%) of mild pleural effusion, who was with an invasive
tumor.
- There was no case of diaphragmatic paralysis as reported by
Manoly (11.8%), Ashleigh Xie (6.7%) and pneumothorax as reported
by some authors: Ashleigh Xie (1.9 %), Popescu, Ye B (0.8%).
* Length of ICU stay
Previously, with the trans-sternal surgery – a very complex
surgery, almost every case had the requirement for ICU stay after
surgery.
Table 3.37 shows that the length of ICU stay has been
improved by VATS. Non-ICU: 68.9%; ICU stay ≤ 24 hours: 24.6%;
24-48: 3.3%; > 48 hours: 3.3%.


21
* Chest tube removal time
According to Table 3.38, most patients have removed their
chest tubes after surgery within 48 hours (68.9%). The other authors
had different results, the withdrawal chest tube time from 1.8 to 4.2
days.
* Postoperative hospital stay
Most patients stayed in hospital less than 7 days (45.9%) and
from 7-10 days (34.4%). The average time of hospital stay after
surgery was 9.8 ± 5.9 days.

4.3.4. Results VATS for thymoma with MG
4.3.4.1. Evaluate the outcome of VATS for thymoma with MG.
+ No patients had worsen MG progression or death during the
monitoring time, all patients’ conditions have improved. The rate of
complete stable remission patients increases along with monitoring
time, especially after over 1 year, this rate reached a peak of 22.6%,
meanwhile unchanged patients stood at only 5.7% (Table 3.41). This
ratio is consistent with the study of Agasthian (2010). According to
table 3.41, after 1 month: the rate of effective operation accounted for
85.2%, the ineffective operation rate accounted for 14.8%, after 1
year: the rate of effective is 94.3%.
+ There were 2 cases who experienced recurred tumor at the pleura
after 1 year of treatment. Author Chao (2015) with 77 patients after
53 months of follow-up had 5 cases of recurrent. According to
Agasthian, after 4 years, there were 02 patients with localized
recurrence and 01 patients in stage IV recurred into the pleura. There
are also many other reports of recurrence: Manoly (2014): 1 in 17
patients, Tagawa (2014): 1 patient has 45 mm thymoma, stage III,
recurred after 3 years.


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CONCLUSIONS
In sixty-one patients thymoma with MG who underwent
VATS in the Department of Thoracic Surgery - Military Hospital 103
during 06 years (2013 - 2019), we had come with the following
conclusions:
1. Characteristics of clinical, imaging and histopathology of
thymoma with MG which performed by VATS

- The mean age was 47.31 ± 10.87; The female-to-male ratio: 0.91.
- Less than 1 year of illness: 82%.
- Most patients (80.3%) were MG class IIA, ptosis symptom was the
most common (71.2%).
- Characteristics of thymoma on CT: round and oval shape (95.1%);
thymoma size varies from 3-6cm: 57.4%; 68.9% had smooth contour,
mediu and above density and extent of contrast absorption are
observed; 26.2% had invasion; the rate of thymoma with calcification
and necrosis is low (6.6%, and 1.6%).
- Characteristics of thymoma on MRI: the rate of the non-invasive
tumor is high (81.5%). Mean tumor size: 35.30 ± 13.92 mm in length,
23.93 ± 13.39 mm in width; CSR index = 1.04 ± 0.17.
- Histopathology: all types are present, most of them were type AB
and B2 (29.5%), there was no cases with thymus carcinoma; the
largest size was in type B2 (46,22 ± 19,37 mm) and the smallest was
in type A (33,73 ± 11,94 mm).
- Thymoma stage: 75.4% of thymoma were in Masaoka stage I, II,
there were 13.1% in stage III and 11.5% in stage IVa. The most
invasive tumor was in type B2 and B3 (77.8% and 100%).


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2. Results of VATS for thymoma with MG at Military Hospital
103
- Technique: right pleural cavity access (57.4%), using 3 trocards
(96.7%): 3rd ICS AAL, 5th ICS MAL and 6th ICS MCL.
- VATS for thymoma with MG was a highly feasible surgery method:
+ High rate of indications for VATS: 86.9%.
+ Mean surgery time: 91.80 - 49.94mins.
+ Average blood loss during surgery: 37,38- 31,58 ml.

- VATS for thymoma with MG was a safe, effective surgery:
+ The rate of complications was low: 3.2% and 13.1%, no deaths
during operation and hospital stay.
+ The rate of non-ICU-stay after surgery was 68.9%.
+ Time to extubate drainage tube within 48 hours after surgery was
68.9%, the average was 57.84 -30.71 hours.
+ Mean time of postoperative hospital stay was 9.8 ± 5.9 days, less
than 10 days was 80.3%.
- Long-term outcome:
+ The rate of effective increases gradually with monitoring time: 1
month: 85.3%, 6 months: 87.9%,> 1 year: 9 4.3 %.
+ 02 cases of recurred thymoma after surgery over 1 year (3.8%)
RECOMMENDATIONS
Based on the results obtained from this study, we make the
following recommendations:
- VATS for thymoma with MG was a safe, effective surgery for MG
patients of all ages. This procedure should be widely applied and be
the first choice for myasthenia gravis patients with thymoma.