**7. Deep circumflex iliac artery flap**

For large oromandibular defects such as subtotal glossectomy with anterior mandibulectomy the options for reconstruction are limited. The composite fibular flap will not easily provide the mass of soft tissue required or the mobility to set it in. A scapular free flap can supply the tissue needed in a chimerical fashion but without the quality or length of bone, and it requires the patient to be turned. Two free flaps can be used such as a fibular with an anterolateral thigh flap, but this lengthens the operating time, and increases morbidity and complications.

A deep circumflex iliac artery flap **(DCIA)** flap is a good single flap option in these circum‐ stances. [35] DCIA flap, a composite osteomusculocutaneous flap of the iliac crest, abdominal wall musculature and overlying skin, has evolved significantly during the previous 30 years since its inception in the late 1970s. With an increasingly reported role for a range of facial, lower limb, and upper limb reconstructions, its most widespread utility has been for hemi‐ mandibular defect reconstruction. Furthermore, the iliac crest has long been used for these various bony reconstructions, its versatility as a composite flap has largely been limited by an understanding of the finer vascular anatomy of the region. Initial attempts to harvest the iliac crest flap using the superficial circumflex iliac artery as its vascular supply in 1978 met with less than ideal results. Although greater success was achieved with the DCIA pedicle flap after the landmark report by Taylor and Townsend in 1979, detailing the DCIA as the main blood supply to the iliac crest, a lack of familiarity with the DCIA perforators in these early studies limited the use of the DCIA flap as a composite flap. [36]

### **7.1. Flap anatomy**

Vessel branches supplying the flap are the ascending branch, which supplies the internal oblique muscle, nutrient endosteal perforators, and periosteal contributions to the iliac crest, and musculocutaneous perforators which supply the overlying skin. The dominant blood supply to the iliac crest flap is provided by deep circumflex iliac (DCIA) artery (length=9 cm and diameter=2.8 mm). The DCIA generally arises deep to the inguinal ligament from the femoral artery or the external iliac artery deep to the inguinal ligament or less frequently from the external iliac artery superior to the inguinal ligament. Venous drainage of the flap is to the deep circumflex iliac vein. This flap does not have a motor reinnervation. Sensory nerve comes from T12 (Figure 10). [37]

**Figure 10.** Anatomy of the DCIA flap

#### **7.2. Flap components**

The iliac crest flap provides for a great many options in flap composition. It may be harvested as a bone-only or a composite flap, which may include muscle, fascia, fat and skin.

#### **7.3. Flap dimensions**

Skin island length commonly is 15 cm and its width 8-10 cm with variable thicknesses. The bony part length is commonly 7 cm and its height 4 cm with 1 cm thickness.

#### **7.4. A common deep circumflex iliac artery flap harvesting technique**

An incision is first made 2 cm above the mid-point of the line between the anterior superior iliac spine and the pubic tubercle to identify the origin of the deep circumflex iliac artery; dissection is performed following the course of the deep circumflex artery. Around the anterior superior iliac spine, one can find the ascending branch arise to enter the abdominal muscula‐ ture, which is dissected free as a backup vessel. The insertion of the abdominal musculature to the inner lip of the iliac bone is detached, with a small muscular cuff preserved between the deep circumflex artery and the iliac crest to protect the minute osteomusculocutaneous branches entering the inner cortex. After detachment of the abdominal musculature along the superior edge of the iliac crest is performed for about 6.5 cm, the deep circumflex artery can be found to sweep medially upward into the abdominal musculature, ending as a musculo‐ cutaneous perforator, nourishing the overlying skin. Meticulous dissection is performed to isolate the vascular pedicle from the abdominal musculature; the skin paddle is centered on the perforator with the previous incision along the iliac crest as the inferolateral margin of the cutaneous flap; finally the flap is harvested to the actual need. [38]

### **7.5. Complications**

femoral artery or the external iliac artery deep to the inguinal ligament or less frequently from the external iliac artery superior to the inguinal ligament. Venous drainage of the flap is to the deep circumflex iliac vein. This flap does not have a motor reinnervation. Sensory nerve comes

The iliac crest flap provides for a great many options in flap composition. It may be harvested

Skin island length commonly is 15 cm and its width 8-10 cm with variable thicknesses. The

An incision is first made 2 cm above the mid-point of the line between the anterior superior iliac spine and the pubic tubercle to identify the origin of the deep circumflex iliac artery; dissection is performed following the course of the deep circumflex artery. Around the anterior superior iliac spine, one can find the ascending branch arise to enter the abdominal muscula‐

as a bone-only or a composite flap, which may include muscle, fascia, fat and skin.

bony part length is commonly 7 cm and its height 4 cm with 1 cm thickness.

**7.4. A common deep circumflex iliac artery flap harvesting technique**

from T12 (Figure 10). [37]

634 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

**Figure 10.** Anatomy of the DCIA flap

**7.2. Flap components**

**7.3. Flap dimensions**

Bulky skin paddle may result in poor cosmetic or functional outcomes. A hernia or abdominal contour deformity can occur in 10% of patients. [37] Postoperative sequelae include injury to the lateral femoral cutaneous and ilioinguinal nerves, which can produce unpleasant dyses‐ thesia or anesthesia. [13] The incidence of gait disturbance and chronic hip pain after the flap harvesting may be greatly decreased by preserving the anterior superior iliac spine and using unicortical bone flap.

#### **7.6. Deep circumflex iliac artery flap updates**

A free vascularized iliac bone flap based on superficial circumflex iliac perforators (SCIPs) has been introduced. Compared with a conventional iliac bone flap, which is based on deep circumflex iliac vessels, this flap is less invasive, less bulky and can include a reliable skin island. In addition, an SCIP-deep inferior epigastric perforator (DIEP) bipedicle soft--tissue flap has been developed, which can contribute to safe transfer of larger DIEP flaps.[39] An anatomical study described variations in DCIA flap. The origin of the DCIA was 5.30 ± 6.22 mm (mean ± SD) superior to the inguinal ligament, and the DCIV was 4.75 ± 3.14 mm medial to the origin of the DCIA. The length of the DCIA from its origin to the level of the anterior superior iliac spine was 59.35 ± 9.06 mm, and the vertical distance between the anterior superior iliac spine and DCIA was 18.50 ± 3.82 mm. With regard to the branching pattern of the ascending branch, most cases (n = 18, 90%) exhibited 1 origin and 2 branches, and the remaining 2 cases (10%) had 2 origins and 2 branches. The distance from the DCIA origin to the branch point in cases exhibiting 1 origin and 2 branches was 36.83 ± 16.10 mm. [40]
