Nghiên cứu đặc điểm giải phẫu và ứng dụng lâm sàng của vạt đùi trước ngoài tự do dạng chùm tt tiếng anh

MINISTRY OF EDUCATION AND TRAINING

MINISTRY OF HEALTH

HANOI MEDICAL UNIVERSITY

DUONG MANH CHIEN

RESEARCH ANATOMICAL
CHARACTERISTICS AND CLINICAL
APPLICATON OF FREE CHIMERIC
ANTEROLATERAL THIGH FLAP
Speciality: Orthopedic and Plastic Surgery
Code: 62720129

MEDICAL DOCTORAL THESIS

HANOI - 2019


The Work has been successfully completed at:
HANOI MEDICAL UNIVERSITY

Scientific supervisor:
Assoc. Prof. Nguyen Bac Hung

Opponent 1: Assoc. Prof. Le Van Doan
Opponent 2: Assoc. Prof. Vu Quang Vinh
Opponent 3: Prof. Vu Duc Moi

The thesis has been defended at University-level Thesis

Evaluation Council held in Hanoi Medical University
At, .... .... (hour), ..../ ..../2019 (date)

This thesis may be found at:
- National Library
- Library of Hanoi Medical University


1
BACKGROUND
The common causes of large and complex defects for different
areas of the body are trauma, burns, tumors... The biggest difficulty is
finding the right material for each type of damage. The Anterolateral
Thigh Flap with its own texture, blood supply is considered an
appropriate material in complex defect reconstruction. Song Y.G. has
first reported the Anterolateral Thigh (ALT) flap in 1984 to head and
neck reconstruction. A special using of ALT flap is chimeric flap. The
chimeric flap is compounded from multiple different flaps, but
consists of only a single different tissue form. Each of the flaps is
usually supplied by different branches from the same source vessel.
In oder to clarifying the anatomical features of the descending branch
of the lateral femoral circumflex artery and the application of ALT
flap, we study the subject: “Research anatomical characteristics
and clinical application of free chimeric Anterolateral Thigh
flap” for purposes of:
1. Describting the anatomical characteristics of the descending
branch of the lateral femoral circumflex artery.
2. Evaluating the results of using the free chimeric
Anterolateral Thigh flap.
New contributions from the thesis:

- Described the anatomical characteristics of the descending of the
lateral circumflex femoral artery to creating chimeric anterolateral
thigh flap: with 60 thighs, the dissertation given the description of the
number, original and size of the descending and the number, size and
type of the perforator of the lateral circumflex femoral artery. From
the results of the research, satisfactory discussions and conclusions


2
were made.
- In the clinical application, the causes, positions and composition of
damages of patients were very various. Patients were reconstructed
by chimeric flap which have thickness and suitable size. The near and
far results have proven that using the free chimeric anterolateral thigh
flap was effective and reliable. New contributions of the dissertation
is reflected in the creation of theoretical and practical basis for the
construction of the process of using free chimeric anterolateral thigh
flap in various complex defects reconstruction.
Thesis outline:
This thesis covers 126 pages, including: preamle (2 pages), the
overview (37 pages), materials and method (16 pages), outcomes (33
pages), discussion (36 pages), conclusion (2 pages), recommendation
(1 page). It consists of 29 tables, 57 figures. There are 101 references,
in Vietnamese and English.
Chapter 1: OVERVIEW
1.1. THE ANATOMICAL CHARACTERISTICS OF THE
DESCENDING BRANCH
1.1.1. The anatomical characteristics of the lateral femoral
circumflex artery.
According to the classic anatomy, the lateral femoral circumflex

artery is the first branch of profunda femoris artery - a major branch
of femoral artery. From the origin, the artery goes between the vastus
medialis muscle and the pelvic lumbar muscles and divided into 3
branches: ascending, transverse and descending branch.
1.1.2. The anatomical characteristics of the descending branch.
1.1.2.1. The origin


3
The descending branch usually is one of three branches of the
lateral femoral circumflex artery. However, there are some
anatomical changes, some cases the descending branch is divided
from femoral or profunda femoris artery.
1.1.2.2. The relation
From the origin, the descending branch running along the
calibrated line which is connected from anterior inferior iliac spine to
lateral patella. Descending branch length is about 8-15 cm. The outer
diameter of artery average 3 mm (2.2-4.0 mm) depeding on the study.
1.1.2.3. The branching muscles
On the way, the descending branch divides many small, short
branches to supply to the rectus femoris, vastus medialis and vastus
lateralis muscles. The branching muscles are rarely described in
anatomical studies.
1.1.3. The characteristics of perforators from the descending
branch
1.1.3.1. The origin of perforator
According to the most of research papers, the perforators in
anterior thigh are mainly separated from the descending branch.
However, some studies also found that the perforators of ascending
and transverse branches involves blood supply to the anterior thigh.

1.1.3.2. The number of perforator
The number of perforator varies according to each report. Sung
W.C. noticed an average of 4.2 perforators originating from the
lateral femoral circumflex artery. Of which about 68% from the
descending branch. Kimata Y. reported an average of 2,3 perforators
from the descending, while Kawai K. was 3,8.
1.1.3.3. The outer diameter at the origin


4
The outer diameter at the origin of perforator of the descending
branch varies according to each report. According to Sung W.C. the
average diameter of perforator is 0,9 mm, proportion of perforator
with diameter bigger than 0,5mm accounts for 68,1%. Yu P. reported
64,3% of cases have diameter greater than 0,5mm.
1.1.3.4. The length of perforator
The length of perforator and the length of descending branch will
determine the length of pedicle of flap. The domestic and foreign studies
that we have read there are no researches describing this detail.
1.1.3.5. The type of perforator
According to Song Y.G. the perforator supply for ALT flap is
septocutaneous perforator, this type accounts for 100%. In 1999, Lou S.K.
studied more about the types of perforator, he classified into four types
based on the way to skin of perforator: musculocutaneous (type M),
septocutaneous (type S), direct cutaneous (type D) and small perforator.
1.1.3.6. Distribution of perforator through the skin
In the most of the studied, the perforator through the skin can be
found in a circle with a radius of 3 cm at the center of the calibrated line
which is connected from anterior inferior iliac spine to lateral patella.
1.2. THE PERFORATOR FLAP IN RECONSTRUCTION

1.2.1. A brief history of flaps
In the beginning, the flaps were used in random flaps, as the skin
was raised without regard to any known blood supply other than to
maintain the presence of the subdermal vascular plexus. Because of
the inherent limited blood supply, random flaps had to be restricted to
rigid length to width ratios to assure viability. The important mark in
the development of flap is when Mc Gregor and Morrgan discovered
that some regions of the body had discrete and relatively large
subcutaneous vessels that pierced the deep fascia to follow a


5
predictable course. Comparatively huge cutaneous flaps, if oriented
along the axis of that vascular pathway, consistently maintained
complete viability, and appropriately were called axial flaps. The
concept of musculocutaneous flap was first used in 1906 by Tanzini.
Pontén deserves credit for reintroducing fasciocutaneous flaps,
although he was not quite sure why the inclusion of the deep fascia
with his “superflaps” resulted in a longer flap survival length than
could be predicted for random flaps of comparable width
1.2.2. Types of perforator flaps are used clinically
1.2.2.1. Conjoined flaps
Harii et al first introduced the concept of combined flaps when they
described a "combined myocutaneous flaps and microvascular free flap".
The purpose of using conjoined flap is to increase the ability to rotate, the
extent of reaching while increasing the vitality of the flap. In essence, flap
is a combination of at least 2 flaps with different anatomical regions, each
region has an independent source.
1.2.2.2. Chimeric flap
The chimeric flap is compounded from multiple different flaps,

but consists of only a single different tissue form. Koshima I. first
introduced the concept of chimeric flap. Hallock G.G. divided the
chimeric flap into three subtypes based on the special blood supply of
each type. In 2015, Kim và CS. divided the chimeric flap into four
subtypes.
1.3. CHIMERIC FLAP FROM THE DESCENDING BRANCH
1.3.1. The concepts of the chimeric ALT flap
1.3.1.1. The chimeric perforator flap
a. The chimeric fasciocutaneous - fasciocutaneous flap


6
The chimeric fasciocutaneous - fasciocutaneous flap with two or
more fasciocutaneous flap with each of the flaps is usually supplied by
different branches from the same source vessel (usually are descending
and transverse branch of the lateral femoral circumflex artery).
b. The chimeric fasciocutaneous – fascia flap
The chimeric fasciocutaneous - fascia flap with fasciocutaneous
flap and fascia flap, each of the flaps is usually supplied by different
branches from the same source vessel.
c. The chimeric fasciocutaneous – adipose flap
The flap is used to recover the skin defects and to fill the tissue
defect due to parry - romberg syndrome or sequelae caused by
radiotherapy.
1.3.1.2. The chimeric perforator - branching muscles flap
The chimeric flap with many component flap that this flap is supplied
by perforator and the other flap is supplied by branching muscles.
1.3.2. The advantages of the chimeric ALT flap
1.3.2.1. Purpose of reconstruction
a. The covering reconstruction

The chimeric ALT flap has many advantages in covering
reconstruction, when it is necessary to reconstruct defects in a distant
position or need to cover different aspects of an organ.
b. The filled and covering reconstruction
The large, complex defects need a special material to filled and
covering reconstruction. The chimeric perforator - branching muscles
flap is used to filled and covering reconstruction.
c. The 3D reconstruction
Toal penile reconstruction requires forming the urethra and penis.
Mehmet M. reported a case of reconstructing a penis with a pedicle


7
chimeric ALT flap.
1.3.2.2. Microsurgical anastomosis
The chimeric flap is compounded from multiple different flaps,
but consists of only a single different tissue form. Each of the flaps is
usually supplied by different branches from the same source vessel.
Therefore, only by an anastomosis (artery and vein) has enough
blood supply for all flaps.
1.3.2.3. The donor site
Another advantage of ALT flap is that with flexible design, flap
can be used to reconstruct larger defects while still being able to
primary close the donor site.
Chapter 2: MATERIALS AND METHOD
2.1. MATERIALS
2.1.1. The anatomical research
The Anatomical research was performed on 30 human cadavers
with 60 thighs. From January 2nd, 2010 to June 1st, 2011.
2.1.2. The clinical research

Selecting a convenient pattern, all patients suffered from
reconstructive surgery by free chimeric ALT flap, 35 patients with 37
free chimeric anterolateral thigh flap. From June 2007 to Januany 2016.
2.2. METHOD
2.2.1. The anatomical research
The method of study is a cross-sectional descriptive study on
cadavers.


8
2.2.1.1. The indexes need to collect: The descending branch, the
perforator, the branching muscles.
2.2.1.2. The tools to collect the data
Nikon D90 camera, Surgical kits, marker kits, measuring kits.
2.2.1.3. The descending branches were exposed and dataes were
collected
a. The descending branches were exposed: the incision along the
medial side of Sartorius muscle from anterior inferior iliac spine to
medial patella. Tracing the pathway of femoral and profunda femoris
arteries to find the descending branches of the lateral femoral
circumflex artery. The branches of the descending were exposed.
b. Dataes were collected
- Qualitative indexes: the origin, relation of descending branches
of the lateral femoral circumflex artery, type of the perforator, the
direction of the perforator, distribution of perforator through the skin.
- Quantitative indexes: length of standard line, length of arteries, The
outer diameter at the origin.
2.2.2. The clinical research
The study describes clinical, retrospective and prospective,
statistical, synthesized then draw general remarks and conclusions.

2.2.2.1. Characteristics of lesions need to be reconstructed by
chimeric flap.
Preoperative evaluation: Time of disease. Number of previous
surgery, surgery method. Causes, location of lesions, size of lesions,
injury status: clean damage or infection, good blood supply or not.
2.2.2.2. The process of creating the chimeric flap.
a. Surgical planning


9
Determine the method of using flap, the source of the artery
received, how to close the donor site. Planning surgical steps.
b. Prepare patients before surgery: At the place to receive flap and
donor site.
c. Surgical procedure
Team 1: Harvesting flap
- Harvesting flap: the incision along the anterior flap, through the
fascia, the descending branches of the lateral femoral circumflex
artery were finded and exposed. Peforators were preserved.
- Chimeric flap design: the first characteristics of the descending
branches, perforators and the branching muscles were evaluated.
Combined with the characteristics of demanges, the chimeric ALT
flap were designed.
- Cutting the pedicle: Cutting the pedicle and transferred to the
receiving place
Team 2: Prepare the receiving place
- Prepare the receiving place: clean the wound, Preparation of
recipient vessels
- Microsurgical anastomosis: end to end anastomosis by Prolen 9.0
or 10.0.

- Suturing the incision: put a drain, suturing the skin
d. Postoperative care
2.2.2.3. The result evaluation
a. The early outcomes
The chimeric ALT flap: The survival of flaps, and condition of
wound healing. The donor site: condition of wound healing,
postoperative complications and functional effects in the area of
donor site.


10
b. The distant outcomes
The chimeric ALT flap: Evaluate each area based on criteria and
scoring (select evaluation criteria depending on each region). The
donor site: Evaluate scarring condition for donor site.
Chapter 3: STUDY RESULTS
3.1. ANATOMICAL RESEARCH RESULTS
3.1.1. The anatomical characteristics of the descending branch
3.1.1.1. The number of the descending branch
We studied on 30 human cadavers with 60 thighs had a total of 73 the
descending branches, of which 47 specimens had one descending branch
(78,3%) and 13 specimens with 2 descending branches (21,7%).
3.1.1.2. The origin of the descending branch
In 73 descending branches, there were 55 branches with the
original from the lateral femoral circumflex artery, 6 branches from
femoral and 12 branches from profunda femoris artery.
3.1.1.3. The outer diameter at the origin of the descending branch
The outer diameter at the origin of the descending branches in
case there are one was an average 2,9 ± 0,1mm. in case there are two
was an average 2,5 ± 0.2mm.

3.1.1.4. The length of the descending branch
The average length of outer descending branches was 262,7 ± 4,3mm,
the average length of inner descending branches was 196,9± 17,5mm.
3.1.2. The branching characteristics of the descending branch
3.1.2.1. The characteristics of the branches
The branches of the descending branch are divided into two types:
The branching muscles and perforators
Table 3.1. The average number of a descending branch


11
The branches

Number

Average/1 descending branch

Branching muscles

654

8,9 ± 0,2

Perforator

226

3,1 ± 0,3

Total

880

12,1 ± 0,2

The total number of branches of descending branches was 880,
including 654 branching muscles and 226 perforators. Average, each
descending branch had 12,1 ± 0,2 branches, including 8,9 ± 0,2 8,9 ±
0,2 branching muscles and 3,1 ± 0,3 perforators.
Table 3.2. Correlation between the branching muscles and
perforators in a descending branch (n=73)
Branching muscles

0-5

6-10

11-15

>15

Total

0

3

2

0

1

6

1

4

4

2

0

10

2

1

10

4

2

17

3

2

10

2

1

15

4

1

5

0

1

7

5

6

0

0

2

8

6

0

4

0

1

5

7

0

2

0

0

2

8

0

0

0

2

2

9

0

0

1

0

1

Total

17

37

9

10

73

Perforator

3.1.2.2. The branching muscles
There were average 7,9±0,4 branches for a vastus lateralis
muscles, of which at most 16 branches. There were average 2.0 ± 0.1


12
branches for a vastus lateralis muscles, 0,5±0,1 branches for a vastus
medialis muscles.
3.1.2.3. The characteristics of perforator of the descending branch
- The average number of perforator: On average, there were 3.7 ± 0.3
perforators on a thigh or 3,1 ± 0,3 perforators on a descending branch.
- Distributing the number of each type of perforator for a
descending branch: in 73 descending branches, there were 226
perforators, of which 183 perforators were musculocutaneous (type
M), 35 perforators were septocutaneous (type S) and 8 perforators
were direct cutaneous (type D).
- The average length of perforator: 29,6 ± 1,1 mm with the longest
perforator was 105,0 mm and the shortest was 3,0 mm.
- The diameter of perforator at origin was 1,1 ± 0,03 mm, of which
the smallest perforator was 0,4 mm and largest was 3,0 mm.
- Type of perforator: The M-type accounted for a high percentage
(81%), the S and D-type accounted for a low percentage (19%).
3.2. CLINICAL RESEARCH RESULTS

3.2.1. The characteristics of damages
3.2.1.1. The causes of damages
Table 3.3. The causes of damages (n
Causes

Number

Anophthalmia

1

Congenital

Microtia

2

disease

Cleft face

1

gender reassignment

1

Due to injury

9

= 37)
Total

Ratio
(%)

5

13,5

10

27,1


13
Soft tissue

Sequelae of

defects

inflammation

1

Burn

7

Due to injury

3

snakebite

2

Benign tumors

1

Malignant tumors

5

Ulcers caused by radiotherapy

4

Scars

Tumors

Total

12

32,4

6

16,2

4

10,8

37

100

The most common cause was scar sequelae (12 cases). Next was
the soft tissue defects with 10 cases, tumors were 6 cases, congenital
disease were 5 and ulcers caused by radiotherapy were 4 cases.
3.2.1.2. The position of damages was reconstructed
A total 78 the position of damages was reconstructed, head and
neck were the most with 46 positions (59%), followed by upper limbs
with 19 positions (24.4%), followed by lower limbs with 10 positions
(12.8%), penis with 2 positions (2.5%) and the chest with 1 position
(1.3%).
3.2.1.3. The tissue is damaged
Table 3.4. The tissue is damaged
Skin, fat

Skin, fat,

and

muscles and

muscles

bone

11

11

15

37

29,7

29,7

40,6

100

The tissue is

Skin and

damaged

fat

Number of
damages
Ratio (%)

Total


14
The damaged tissue composition was diverse, in which fat lesions
had 11 cases, skin lesions with muscle tendons had 11 cases and skin,
fat, muscles and bone damage had 15 cases.
3.2.2. The characteristics of using flaps
3.2.2.1. Characteristics of ALT flaps before dividing into chimeric
flaps
Table 3.5. Number of microsurgical anastomosis
Type of anastomosis
Number of

Artery

Vein

1

1

2

3

Number of flaps

37

4

32

1

Total of anastomosis

37

Ratio (%)

100

anastomosis

71
10,8

86,5

2,7

- Number of perforators for flap: there were 80 perforators
(average 2,2 perforators for a flap). Of which, 31 flaps had 2
perforators and 6 flaps had 3 perforators.

- Size of flaps: The average length of flap was 203 ± 10 mm The
average width of the flap was 90 ± 4 mm.
- Thickness of flaps: 3 flaps were not thinned, 6 flaps were primary
thinned and 18 flaps were thinned with microsurgical technique. The
average thickness of flaps before thinned was 17.1 ± 1 mm and after
thinned was 7.6 ± 1 mm.
- Composition of flaps: the adipocutaneous flap had 20 (54,1%),
fasciocutaneous flap had 11 (29,7%) and musculocutaneous flap had
6 (16,2%).
3.2.2.2. Characteristics of ALT flaps after dividing into chimeric
flaps


15
37 ALT flaps after dividing into chimeric flaps, there were 75
single flaps, including 36 chimeric flaps had 2 single flaps and 2
chimeric flaps had 3 single flaps.
Table 3.6. The average length of perforator
Perforator

Number

The average length (mm)

Perforator 1

37

47,2 ± 1,8

Perforator 2

37

53,2 ± 2,7

Perforator 3

6

46,6 ± 6,7

Total

80

50,0 ± 1,6

- The distance between the origin of perorator 1 and 2 was
average 48.5 ± 3.8 mm, the distance between the origin of perorator 2
and 3 was 36,1 ± 4,4 mm.
Table 3.7. Type of perforator
Perforator

Type of perforator

Total

M

S

D

Perforator 1

29 (78,4%)

8 (21,6%)

0 (0%)

37

Perforator 2

31 (83,8%)

6 (16,2%)

0 (0%)

37

Perforator 3

6 (100%)

0 (0%)

0 (0%)

6

Total

66

14

0 (0%)

80

Ratio (%)

82,5

17,5

0

100

- Composition of single flaps: the adipocutaneous flap had 47,
fasciocutaneous flap had 20, muscle flap had 4, musculocutaneous
flap had 3 and fascial flap had 1.
- Size of single flaps: 37 number 1 single flaps, the average length
of single flaps was 125 ± 7 mm, the average width of single flaps was

16
86 ± 4 mm. 33 number two single flap 2, the average length was 88 ±
7 mm and the average width was 63 ± 6 mm.
3.2.2.3. The characteristics of reconstruction
17 chimeric ALT flaps (45,9%) were used to covering
reconstruction. 3 chimeric flaps were used to reconstruct the organ, 1
chimeric flap was used to filled reconstruction and 17 flaps were used
to combined reconstruction.
Table 3.8 Reconstruction related to the location of the damages
Direction

Same

opposite

direction

direction

Head and neck

17

4

21

Upper limb

8

2

10

Lower limb

2

3

5

Penis

1

0

1

Total

28

9

37

Location

Total

3.2.2.4. Vessels of source receiver
Table 3.9. Arteries of source receiver (n=37)
Vessels of source
receiver

Arteries

Number Total

Location
Head and neck

Upper limb

Facial a.

18

Superficial temporal a.

3

Radial a.

8

Radial a. in anatomical

2

21

10

snuffbox
Lower limb

Posterior tibial a.

2

Anterior tibial a.

3

5


17
Vessels of source
receiver

Arteries

Number Total

Location
Penis

Deep inferior epigastric a.

1

Total

1
37

3.2.3. Postoperative general results
3.2.3.1. The early outcomes
Table 3.10. The survival of flaps
The survival of

Total

Partial

Total

flaps

survival

survival

necrosis

30

3

4

37

81,1

8,1

10,8

100

Number of
chimeric flaps
Ratio (%)

Total

In 37 chimeric ALT flaps were used, 30 flaps were total survival
(81,1%), 3 flaps were partial survival (8,1%) and 4 were total
necrosis (10,8%).
Table 3.11. The general results (n=37)
Results

Excellent

Good

Average

Weak

Total

Donor site

28

7

1

1

37

Receipt site

23

7

3

4

37

In the donor site, the excellent result was 28 cases, good result
was 7 cases, average result was 1 case and weak result was 1 case. In
the receipt site, the excellent result was 23 cases, good result was 7
cases, average result was 3 cases and weak result was 4 cases.


18
3.2.3.2. The distant outcomes
We reexamined 3 months after surgery for 35 patients (with 37
flaps).
Bảng 3.13. The distant outcomes
Results

Excellent

Good

Average

Weak

Total

Donor site

30

6

1

0

37

Receipt site

26

5

1

5

37

In the receipt site, the excellent result was 26 cases, good result
was 5 cases, average result was 1 case and weak result was 5 cases.
In the donor site, the excellent result was 30 cases, good result was 6
cases and average result was 1 case.
Chapter 4: DISCUSSION
4.1. CHARACTERISTICS OF THE DESCENDING BRANCH
4.1.1. The anatomical characteristics of the descending branch.
In 73 descending branches, there were 55 descending branches
with the origin from the lateral femoral circumflex artery (75,3%), 6
branches (8,2%) from femoral and 12 branches (16,5%) from

profunda femoris artery.
4.1.2. The branching characteristics of the descending branch
4.1.2.1. The characteristics of the branching muscles
The number branches for a vastus lateralis muscles was the most
with the average 7.9 ± 0.4 branches for 1 muscle. There was an
average of 2.0 ± 0.1 branches for a vastus lateralis muscle and
0,5±0,1 branches for a vastus medialis muscle. According to many


19
references, we found that the authors did not describe the
characteristics of the branching muscles.
4.1.2.2. The characteristics of perforators
In 60 specimens, there were 226 perforators from descending
branches, average of 3.7 ± 0.3 perforators on a thigh. This result is
similar to the other authors such as Kimata Y. the average 2.3
perforators on a thigh, Kawai K. is 3.8 or Tansat T. is 2.2.
4.1.2.3. Correlation between the branching muscles and perforators
In 73 descending branches, there were 57 descending branches
(78%) with two or more perforators. Therefore, with about 78% of cases
we can create the chimeric fasciocutaneous - fasciocutaneous flap.
Considering the case had 1 perforator and 6 branching muscles, we had
64/73 (87,7%) descending branches. So there are about 91.8% of cases
we can create the chimeric perforator - branching muscles flap.
4.2. CHARACTERISTICS OF USING THE CHIMERIC ALT
FLAP
4.2.1. The advantages of the free chimeric ALT flap
4.2.1.1. Lesions were reconstruction differently in many locations
and due to many different causes
Our research, the most common cause was sequelae scarring (12

cases). Next, soft tissue defects had 10 cases, cause of tumors with 6
cases, followed by congenital malformations with 5 cases and finally,
ulcerative sequelae of radiotherapy with 4 cases. Based on location
of lesions, the most common neck and head area with 46 positions
including lesions in lips, nose, cheeks, optic, midface, ears, neck.
Next was the upper limb with 19 positions including hands, arms and
forearms. Lower limb with 10 positions, finally the penis 2 and the


20
chest had a lesion. A total of 78 lesions were reconstruction by 37
free chimeric ALT flaps.
4.2.1.2. Size of flaps modified depending on size of the lesions
The average length of flap was 20.3 ± 1 cm with the smallest was
9 cm and the largest was 37 cm. The average width of the flap was 9
± 0.4 cm, the smallest was 5 cm and the largest was 15 cm.
4.2.1.3. The composition of flap is diverse
In principle, the defects are reconstructed with materials of similar
tissue composition. On the other hand, with complex defects,
reconstruction is not only recover or filling but also 3D
reconstruction. Therefore, it is necessary to have a material with
diverse tissue components and can be divided into different parts that
the result is the best. The chimeric ALT flap has many characteristics
to achieve the above requirements
4.2.1.4. Number of microsurgical anastomosis
In total, there were 37 aterial anastomosises, 71 varicose
anastomosises. Thus, with 78 lesions in 78 different positions, when
using free flaps, at least 78 flaps are required with 78 aterial
anastomosises and from 78 to 156 varicose anastomosises. However,
when using the chimeric flaps, we only have to use 37 flaps with a

smaller

number

of

microsurgical

anastomosis

(37

aterial

anastomosises and 71 varicose anastomosises.).
4.2.2. The characteristics of using flaps
4.2.2.1. The chimeric ALT flap in covering reconstruction
Our study had 17 chimeric ALT flaps (45.9%) used for the covering
reconstruction at skin or mucosa defects. We used the chimeric ALT
flaps for the covering reconstruction in some cases: Firstly, lesions
occur in many locations far away from each other, in which each flap


21
will reconstruct for a lesion. Second, the full thickness defects in the
cheek. Thirdly, defects are large in size, using a normal flap will have
to be flap with large size, then can not close directly to the donor site.
Finally, we used chimeric ALT flap for long defects.
4.2.2.2. The chimeric ALT flap in filled reconstruction
In clinical practice, sometime surface defects and dead spaces are

not in the same position, we cannot be reconstructed by a flap. In
cases, a chimeric ALT flap with a flap is used to fill the dead zone,
while the other flap is used to cover.
4.2.2.3. The chimeric ALT flap in 3D reconstruction
Our research has 19 chimeric ALT flaps in 3D reconstruction.
Including 16 flaps were used for head and neck, 2 flaps for upper
limd and 1 flap for penis.
4.2.3. Postoperative general results
4.2.3.1. The survival of flaps
The early outcomes, in 37 chimeric ALT flaps were used, 30 flaps
were total survival (81,1%), 3 flaps were partial survival (8,1%) and
4 were total necrosis (10,8%). In 75 single flaps, 64 flaps were total
survival (85,4%), 1 single flap was partial survival án 10 single flaps
were total necrosis.
4.2.3.2. The donor site
29 cases were primary healing, 6 cases were second healing and 2
case were severe complications, muscles in thigh was partial necrotic.
The cause was a larger defect but we still try to close primary.
4.2.3.3. Complications and causes of failure
7 chimeric ALT flaps were necrosis, in which partial necrosis had
3 flaps and complete necrosis had 4 flaps. We found that, with 4 flaps


22
were completely necrosis, the cause of hematoma under the flap had
2 cases and the cause of intraoperative thrombosis had 2 caes.
4.2.3.4. The distant outcomes
Evaluate the results after 3 months, at the receipt site we assessed
based on the color, thickness of flaps, contour, hair on flaps… which
gived 4 levels of excellent, good, average and weak results. In the

receipt site, the excellent result was 26 cases, good result was 5 cases,
average result was 1 case and weak result was 5 cases. In the donor
site, the excellent result was 30 cases, good result was 6 cases and
average result was 1 case.
CONCLUSION
1. CHARACTERISTICS OF THE DESCENDING BRANCH
1.1. Descending branch
- Number: 73 descending branches, of which 47 thighs had 1 and
13 thighs had 2 descending branches.
- Origin: 55 branches from the lateral femoral circumflex a., 6
branches from femoral and 12 branches from profunda femoris a.
- The outer diameter: in case there are one is an average 2,9 ± 0,1mm. in
case there are two is an average 2,5 ± 0.2mm.
- The length: outer descending branches was 262,7 ± 4,3mm,
inner descending branches was 196,9± 17,5mm.
- The branches: 880 branches including 654 branching muscles
and 226 perforators.
1.2. Perforators.
- Number: there were 226 perforators, average 3,1 ± 0,3
perforators on a descending branch.
- The average length of perforator: 29,6 ± 1,1 mm with the longest
perforator was 105,0 mm and the shortest was 3,0 mm.


23
- Type of perforator: The M-type accounted for a high percentage
(81%), the S and D-type accounted for a low percentage (19%).
1.3. The branching muscles
- There were 654 branching muscles. Average each descending
branch had 8,9 ± 0,2 branching muscles.

- 7,9±0,4 branches for a vastus lateralis m., 2.0 ± 0.1 branches for a
vastus lateralis m., 0,5±0,1 branches for a vastus medialis m.
2. CLINICAL RESULTS
2.1. The characteristics of damages
- The causes of damages: scar sequelae (12 cases), soft tissue
defects (10 cases), tumors (6 cases), congenital disease (5 cases) and
ulcers caused by radiotherapy (4 cases).
- The position of damages: head and neck with 46 positions, upper
limbs with 19, lower limbs with 10, penis with 2, chest with 1.
- The tissue is damaged: fat lesions had 11 cases, skin lesions with
muscle, tendons had 11 cases, composite lesions had 15 cases.
2.2. The characteristics of using flaps
2.2.1. The characteristics of flaps before dividing into chimeric.
- Size of flaps: The average length of flap was 203 ± 10 mm The
average width of the flap was 90 ± 4 mm.
- Thickness of flaps: before thinned was 17.1 ± 1 mm and after
thinned was 7.6 ± 1 mm.
- Composition of flaps: adipocutaneous had 20 (54,1%),
fasciocutaneous had 11 and musculocutaneous had 6.
2.2.2. The characteristics of flaps after dividing into chimeric.
- Average length of single pedical 1 was 106 ± 4 mm and single
pedical 2 was 161 ± 6 mm.
- Size of single flaps: average length was105 ± 5 mm and average
width was 72 ± 3 mm.