Free DIEP Flap Breast Reconstruction

Introduction

Breast reconstruction using the deep inferior epigastric perforator (DIEP) flap has become the gold standard for autologous breast reconstruction for most plastic surgeons. The principle benefit of the DIEP flap compared to other flaps is that the abdomen is the preferred and favorable donor site for most women because many will achieve an improvement in abdominal contour with minimal impairment in function. The DIEP flap utilizes the skin and fat from the lower abdomen but does not harvest any of the underlying rectus abdominis muscle. The deep inferior epigastric artery and vein are dissected away from the muscle, thus preserving the continuity and innervation of the rectus abdominis.

This chapter will provide an in-depth review of the DIEP flap and provide case examples to assist the reader with understanding the risks and benefits of this operation. Other relevant topics will include a review of algorithms, monitoring techniques, and the current technological advancements that have facilitated the ability to perform this operation.

Indications and Contraindications

Indications for the DIEP flap are numerous and include but are not limited to patient demand, dissatisfaction or failure of prosthetic devices, and previous radiation therapy. Although autologous reconstruction is performed less frequently than prosthetic reconstruction, many patients do not want prosthetic devices and prefer using their own tissues. DIEP flaps can be performed immediately following mastectomy or on a delayed basis. This flap is considered in patients with a variety of breast sizes and ultimately depends upon the amount of skin and fat available in the abdominal area to reconstruct a breast of desired shape, volume, and contour.

Contraindications to the DIEP flap are mildly controversial. Some surgeons feel that DIEP flaps should not be performed immediately following a mastectomy if postoperative radiation therapy is likely due to the possibility of flap shrinkage and soft tissue distortion; however, others feel that these adverse events are infrequent and therefore perform the DIEP flap regardless of radiation. Other contraindications to performing the DIEP flap include the lack of a suitable perforator. This can be assessed preoperatively using vascular imaging modalities such as computerized tomographic angiography (CTA) or magnetic resonance angiography (MRA). In patients with severe abdominal lipodystrophy with a large pannus, the DIEP flap may not be ideal due to the thickness of the flap and the likelihood of fat necrosis; however, proper tailoring of the flap can minimize these adverse events. Prior abdominal surgery is usually not a contraindication to performing a DIEP flap unless there is a paramedian incision that has violated the system of deep perforators. Midline abdominal incisions often facilitate the performance of bilateral DIEP flaps but may limit the amount of available tissue for unilateral DIEP flaps. Patients with elevated body mass index (BMI 30–35) are usually good candidates for this flap; however, when BMI exceeds 35, adverse events such as seroma, infection, and delayed healing may increase.

Advanced patient age (>65 years) is considered by some to be a relative contraindication for DIEP flaps. Active tobacco use is a relative contraindication and is typically associated with delayed healing of the mastectomy skin flaps as well as the abdominal donor site.

Preoperative Evaluation and Special Considerations

Patient selection includes a thorough history and physical examination, review of the reconstructive options, an understanding of patient expectations, and surgeon recommendations. Important details of the physical examination include body weight, patient height, body mass index (BMI), and estimated breast volume. Given the variation in breast size and body habitus, an understanding of symmetry following the first operation or subsequent operations is determined. The abdomen is the preferred donor site for most surgeons and patients and the DIEP flap is usually the best option. The most important physical finding related to the abdomen is a sufficient quantity of skin and fat to reconstruct the desired breast volume. Most women have experienced childbirth and have an excess of abdominal skin and fat. Although a woman may be slender, with a paucity of abdominal fat, she may still be a candidate for a DIEP flap if the reconstructive requirements are low. In women who are overweight or obese, a DIEP or free TRAM flap may be considered; however, the flap must be tailored to sustain adequate perfusion throughout to minimize the incidence of fat necrosis.

The decision as to whether to use a perforator flap or a musculocutaneous flap can be difficult. The author's original algorithm was based on breast volume, abdominal fat volume, perforator diameter, number of perforators, patient age, tobacco use, and whether the reconstruction is unilateral or bilateral. In general, a DIEP flap is performed when the volume requirement is less than 1000 cc and the patient has mild to moderate abdominal lipodystrophy. A muscle-sparing free TRAM flap is usually performed when the volume requirement exceeded 1000 cc or if the patient has severe abdominal lipodystrophy ( Table 3.1 ). The author's indications for a pedicle TRAM and superficial inferior epigastric artery perforator flap are also included. In this author's practice, the DIEP flap constitutes approximately 70% of all abdominal flaps followed by the muscle-sparing (MS-2) free TRAM ( Fig. 3.1 ).

Surgical Technique