The document describes the anatomy and surgical technique for harvesting a deep circumflex iliac artery (DCIA) flap. The DCIA flap can include bone from the iliac crest and either the internal oblique muscle or just the overlying muscles. The standard incision is an S-shaped incision over the iliac crest. Dissection proceeds through the muscle layers to identify the DCIA and its branches. The flap is then harvested by ligating the DCIA, performing osteotomies, and transecting the pedicle once the reconstruction site is ready. Closure involves reapproximating the muscles and skin.

1. DEEP CIRCUMFLEX ILIAC ARTERY
FLAP
DR JAMEEL KIFAYATULLAH
Oral maxillofacial surgeon Khyber
College of dentistry,Peshawar

2. DCIA FLAP
Vascular anatomy
• The vascular system will depend on the deep circumflex
iliac artery (DCIA) which has a diameter of 1.5 -2.0
mm.
• The concomitant vein has a diameter of 2.5 – 3.0 mm.
• The length of the pedicle =5 cm.
• The ascending branch is located beneath internal
oblique muscle running superiorly.
• The DCIA is located beneath the transverse abdominis
in the groove between the transverse abdominis and
the iliacus fossa.

3. DCIA FLAP ANATOMY

4. Anatomical variations
• There are three main anatomical variations of the
ascending branch, which will have an influence on the
flap harvest.
• In 65 % of the cases, the ascending branch originates
from the DCIA wihin one cm medial to the ASIS.
• In 20 % of the cacses there is no single dominant
ascending branch. The internal oblique is supplied by a
series of small branches of the DCIA.
• In 15 % of the cases ascending branch originates in a
more medial location.

5. Anatomical variations of ascending
branch

6. Muscular anatomy
• When dissecting through the external oblique, the
internal oblique and the transverse abdominis muscle
one can readily recognize the muscle layers by the
direction of the muscle fibers.
• The muscle fibers of the external oblique muscle run
inferiomedially.
• The muscle fibers of the internal oblique muscle run
superiomedially perpendicular to the external oblique
muscle fibers.
• The muscle fibers of the transverse abdominus muscle
run medially.

7. Surgical Landmarks
Design of flap
• The following landmarks are identified and
marked:
• The anterior superior iliac spine (ASIS)
• The midpoint of the inguinal ligament (Femoral
artery is palpable)
• Superior border of the iliac crest

8. Surgical Landmarks

9. DCIA FLAP
• The harvested myo osseous flap should
include:
• DCIA
• Iliac crest
• Internal oblique muscle
• Ascending Branch
• Although a relatively large bone flap (up to 18
cm) can be harvested, large bone flaps may
lead to higher risk of donor site morbidity (e.g:
hernia, disfigurement, gait disturbance).

10. DCIA FLAP

11. INCISION
• The standard size is around 10 cm in length and up to 5 cm in height.
• A S-shaped incision is used starting at the superior border of the iliac
crest (with the assistant pulling the overlying skin medially, thereby,
end result of surgical scar will be resting laterally on bone edge in
avoiding long term abrasion irritation of clothing), curving medially
through the anterior superior iliac spine and curving inferiorly through
the midpoint of the inguinal ligament.
The exact osteotomy line will depend on the planned reconstruction.
We will here show the harvest of a straight segment(s) used for
mandibular body reconstruction.

12. INCISION

13. Main structures involved in the flap
harvest
• The main layers and structures encountered
during the flap harvest are:
• Skin
• Iliac crest
• External oblique
• Internal oblique
• The ascending branch
• Transverse abdominus muscle
• Deep circumflex iliac artery (DCIA)
• Iliacus muscle

14. Main structures involved in flap
harvest

15. Patient positioning
• For the harvest the patient is placed supine with the
buttocks elevated on the donor site by using eg. a
bean bag.

16. FLAP HARVEST WITH INTERNAL
OBLIQUE MUSCLE
• The skin is incised and dissection is carried
down to the external oblique fascia

17. EXTERNAL OBLIQUE FASCIA
DISSECTION
• The external oblique fascia (as external
oblique running laterally, it is very thin and
almost only fascia can be seen) is incised and
retracted to expose the internal oblique
muscle.

18. FLAP HARVEST

19. INTERNAL OBLIQUE MUSCLE
DISSECTION
• If the internal oblique muscle is harvested
together with the bone flap, the maximum internal
oblique muscle that can be harvested, starting 2
cm laterally from the midline and end at the iliac
crest.
• The internal oblique muscle is incised as needed
and raised laterally. The ascending branch of the
DCIA running on the undersurface of the muscle
is identified.

20. FLAP HARVEST

21. Flap harvest
• Retrograde dissection is performed along the
ascending branch to the main trunk (External Illiac
Artery). The dissection is then continued until the
bifurcation of the external iliac artery is reached.
• Now, dissect antegradly to identify the DCIA.There is
a variation where the Ascending branch can arise
from the DCIA or directly from External Illiac Artery.

22. Bifurcation of external iliac artery

23. Transverse Abdominus dissection
• Dissection is now carried superiolaterally along
the DCIA through and beneath the transverse
abdominal muscle.
• An incision of the transverse abdominal muscle is
along the dissection of DCIA or 2 cm medially to
the iliac crest.

24. Transverse abdominus dissection

25. Flap harvesting
• The distal end of the DCIA is ligated.

26. Iliacus incision
• The iliacus is incised to expose the osteotomy
sites. In order to protect the DCIA, the incision
is made 1-2 cm inferior to the groove where
the DCIA is located.

27. Iliacus muscle incision

28. Osteotomy
• The osteotomy is performed according to the
planned outline.

29. Pedicle transection
• When the reconstruction site is ready, the
pedicle can be transected.

30. Pedicle transection

31. Harvest without internal oblique muscle

32. Skin incision
• The skin is incised and dissection is carried
down to the external oblique fascia.

33. External oblique fascia incision
• The external oblique fascia is incised and retracted
to expose the internal oblique muscle.

34. Blunt dissection along external iliac
artery
• The transverse abdominal muscle and the inguinal
ligaments are identified.
• The external iliac artery can be found by palpation
at midpoint of the inguinal ligaments.
• Meticulous blunt dissections are performed along
the external iliac artery. The DCIA is identified by its
course emerging laterally from the external iliac
artery and entering the groove between transverse
abdominous muscle and the iliac fossa

35. Blunt dissection along external iliac
artery

36. Transverse abdominus muscle
dissection
• Dissection is now carried superiolaterally along the
DCIA through and beneath the transverse
abdominal muscle.
• An incision of the transverse abdominal muscle is
made from the inferior border to the planned
resection site. The incision is made 2 cm medially to
the iliac crest.

37. Transverse abdominus muscle
dissection

38. Ligation of DCIA
• The distal end of the DCIA is ligated.

39. LIGATION OF DCIA

40. ILIACUS MUSCLE DISSECTION
The iliacus is incised to expose the the inner
table of Illiac bone prepared for osteotomy. In
order to protect the DCIA, the incision is made
1-2 cm inferior to the illiacus groove where
the DCIA is located.

41. ILIACUS MUSCLE DISSECTION

42. OSTEOTOMY

43. osteotomy
• The osteotomy is performed according to the
planned outline

44. Pedicle transection and reconstruction
site ready

45. Pedicle transection
• When the reconstruction site is ready, the
pedicle can be transected.

46. Closure

47. closure
• The transverse abdominis muscle is sutured to
the iliacus.

48. closure

49. closure
• Harvest without internal oblique:
• The cut edges of the external oblique, internal
oblique and transversus abdominus muscles
are then reapproximated using resorbable
horizontal mattress sutures.

50. Drain placement

51. Drain insertion
• A drain is inserted between the transverse
abdominous muscle and internal
oblique/external oblique muscles. the skin
closed in primary fashion. Pressure dressing is
then applied.