**4.1 Applied anatomy**

DIEAP flap is based on musculocutaneous perforators arising from the deep inferior epigastric artery. The regional vascular anatomy of the DIEAP flap is the same as the TRAM flap except one should be familiar with the location and course of the perforators to be dissected both anatomically and surgically. As abdominal wall is nourished by two epigastric arterial systems. The superior epigastric arises from the internal mammary artery and the deep inferior epigastric artery arises from the external iliac artery. After originating from an external iliac artery, it runs upwards and medially and goes behind the posterior rectus sheath where it runs intramuscularly and gives two branches. These branches run intramuscularly and then anastomoses with arcades of various vessels at the subdermal level. These myo-cutaneous perforators apart from the muscle route, can directly supply to the skin also. Once traversing

through the muscle, these perforators further pierce the anterior rectus sheath and then supply the subcutaneous tissue and skin. Most of these perforators are found around the umbilicus and in the medial and middle 1/3rd of the muscle [4].

## **4.2 Flap harvesting**

*Pre-operative considerations*: It is important to evaluate the patient as a whole. Any comorbid conditions and history of smoking should be evaluated and smoking should be stopped at least 3 weeks before surgery. Also, any previous abdominal surgeries like abdominoplasty, liposuction, or Caesarian section scar are not a good candidate for DIEP flap reconstruction. The defect size and volume is assessed comparing with contra-lateral side (**Figure 9**).

*Pre-operative mapping of perforators*: Although there are several tools like handheld Doppler, color Doppler scan, and contrast-enhanced CT scan. The current investigation of choice is HRCT angiography which determines the location and size of perforators along with their branching pattern.

*Marking***:** The marking of the DIEAP flap is the same as the TRAM flap or abdominoplasty incision with an additional marking for perforators. A boat-shaped or elliptical incision is marked joining the two sides ASIS, umbilicus, and mons pubis (**Figure 10**).

*Positioning***:** The patient is in a supine position with the arm abducted and supported on both sides over the armrest.

*Technique***:** In general, the lower border of an ellipse is incised first and subcutaneous tissue is dissected with dissection of the superficial inferior epigastric vein on both sides. These veins can be utilized for supercharging the flap in case of venous compromise. The next step is the identification of perforators of the deep inferior epigastric artery. One can dissect both sides of perforators and choose the suitable one. For that one side is dissected first and the other side is preserved in case of nonavailability or reduced size and pulsation of perforators. The circumferential incision along the umbilicus is made and the superior incision is completed by doing careful dissection around the umbilicus pedicle. The deep fascia is identified initially from the superior incision and then dissected from lateral to medial. The perforators start

#### **Figure 9.** *Pre-operating defect after mastectomy (for secondary reconstruction).*

**Figure 10.** *Marking for DIEAP flap.*

**Figure 11.** *Dissection of perforators of DIEAP flap.*

*Flaps for Breast Reconstruction DOI: http://dx.doi.org/10.5772/intechopen.114019*

**Figure 12.** *Harvested DIEAP flap.*

**Figure 13.** *Immediate post-operative result after insetting on table.*

```
Figure 14.
Post-operative result.
```
from the lateral border of the rectus sheath. We try to dissect all perforators that come in the way or are predefined by radiological imaging and an appropriate perforator is chosen with adequate diameter and pulsation. The perforators are dissected till it pierce the anterior rectus sheath. A longitudinal (**Figure 11**) incision is made into the anterior rectus sheath and the perforator is further dissected en route to rectus muscle whether it further goes through the posterior rectus sheath. The perforator is dissected from its origin of the deep inferior epigastric artery which is further dissected till its origin inferno-medially (**Figure 12**) from the external iliac artery and the flap is islanded and harvested with its pedicle. Zone IV of perfusion is usually discarded and the flap is inset at the recipient site and followed by anastomosis.

The donor area (**Figure 13**) is closed primarily. In case of difficult approximation, the superior part of the abdominal flap is dissected in the midline and a neo-position of the umbilicus is created. The rectus sheath is repaired with a braided ethibond suture. The drains are kept in situ. DIEAP flap can provide a good volume without any donor site morbidity (**Figure 14**).

## **4.3 Complications**

Partial and total flap failure. Wound dehiscence at the donor area.
