Residency · Residency · Plastic Surgery

Autologous Breast Reconstruction: DIEP Flap

Introduction

The deep inferior epigastric perforator (DIEP) flap is the gold standard for autologous breast reconstruction. Transfers lower abdominal skin and fat based on perforators from the deep inferior epigastric artery (DIEA) and vein (DIEV). Preserves the rectus abdominis muscle entirely (no muscle sacrifice). Evolution from the pedicled TRAM → free TRAM → muscle-sparing free TRAM → DIEP. Provides natural, warm, sensate tissue that ages with the patient. Preferred option for post-radiation reconstruction.

Anatomy

Deep Inferior Epigastric System

DIEA: arises from the external iliac artery, enters the rectus sheath at the arcuate line. Courses superiorly on the posterior surface of the rectus abdominis. Gives off musculocutaneous perforators that traverse through the rectus muscle to supply the overlying skin and fat. Perforator rows: medial row and lateral row.

Medial row perforators: more common dominant perforators; shorter intramuscular course (easier dissection). Lateral row perforators: longer intramuscular course; may require more muscle splitting. Dominant perforators: most commonly found in the periumbilical region. DIEV: paired venae comitantes that drain into the external iliac vein; also superficial inferior epigastric vein (SIEV) provides secondary drainage.

Perfusion Zones (Hartrampf Zones)

Zone I: ipsilateral to the pedicle, medial to semilunar line — best perfusion. Zone II: ipsilateral to the pedicle, lateral to semilunar line — good perfusion. Zone III: contralateral, medial — moderate perfusion (crosses midline). Zone IV: contralateral, lateral — poorest perfusion; should NOT be included in the flap. DIEP flap perfusion generally includes Zones I, II, and III; Zone IV is discarded.

Angiosome Considerations

The superficial inferior epigastric artery (SIEA) supplies the same territory but from a superficial source. Choke vessel connections between DIEA perforasomes determine the extent of reliable tissue perfusion. Single dominant perforator may adequately perfuse Zones I-III if large caliber (>1.5 mm).

Preoperative Planning

Patient Selection

Adequate lower abdominal tissue (sufficient volume for breast reconstruction). BMI ideally <35 (higher BMI increases complications but is not absolute contraindication). No prior abdominoplasty (relative contraindication; previous abdominal liposuction may be acceptable). Prior cesarean section is NOT a contraindication (perforators may be altered but are usually sufficient).

Non-smoker (or quit >4 weeks preoperatively). No plans for future pregnancy (abdominal wall integrity consideration). Prior abdominal surgery: assess for prior DIEA ligation, rectus muscle disruption.

CT Angiography

Gold standard for preoperative perforator mapping. Identifies: number, location, caliber, and intramuscular course of perforators. Determines dominant perforator and row (medial vs. lateral). Assesses DIEA caliber and branching pattern (Type I: single trunk, Type II: bifurcating, Type III: trifurcating). Evaluates patency of recipient internal mammary vessels. Identifies SIEV caliber (backup venous drainage option).

Recipient Vessel Assessment

Internal mammary artery and vein (IMA/IMV): preferred recipient vessels. Accessed through 3rd or 4th rib cartilage resection or intercostal space approach. Consistent anatomy; reliable caliber. Thoracodorsal vessels: alternative recipients, especially if IMA previously used or unavailable. Internal mammary perforators: avoid in-the-muscle dissection; less reliable caliber.

<image>Preoperative planning illustration for DIEP flap breast reconstruction. An anterior view of the abdomen shows the deep inferior epigastric artery arising from the external iliac artery, coursing superiorly on the posterior rectus surface, with multiple perforators emerging through the rectus muscle. Dominant perforators in the periumbilical region are highlighted and labeled with their medial versus lateral row position. The four Hartrampf perfusion zones are color-coded on the abdominal skin: Zone I (brightest, best perfusion) ipsilateral-medial, Zone II ipsilateral-lateral, Zone III contralateral-medial, and Zone IV (dimmest, discard) contralateral-lateral. The skin paddle design is shown as an ellipse from hip to hip centered below the umbilicus, with Zone IV marked for excision. An inset shows the CTA cross-section identifying a dominant medial row perforator traversing the rectus abdominis.</image>

Surgical Technique

Flap Harvest

1. Mark the skin paddle: lower abdominal ellipse from hip to hip (similar to abdominoplasty design)
2. Begin incision on the side contralateral to the pedicle (allows assessment of perforators through the anterior rectus sheath before committing)
3. Raise flaps superficial to Scarpa's fascia laterally; identify and preserve the SIEV as a bailout option
4. Identify perforators penetrating the anterior rectus sheath
5. Select dominant perforator(s) confirmed by preoperative CTA
6. Open the anterior rectus sheath around the chosen perforator(s)
7. Perform intramuscular dissection: split the rectus muscle fibers along their longitudinal orientation to trace the perforator to the main DIEA/DIEV trunk
8. Divide small motor nerve branches to the rectus as needed (preserve if possible)
9. Dissect the DIEA/DIEV pedicle to its origin from the external iliac vessels (pedicle length typically 10-14 cm)
10. Clip and divide the pedicle after recipient vessels are prepared 11. Trim Zone IV (and excess Zone III if not needed for volume)

Fascial Closure

Primary closure of the anterior rectus sheath (critical to prevent hernia/bulge). Mesh reinforcement (synthetic or biologic) if primary closure is under tension. Mesh decreases donor site bulge rates. Quilting sutures to reduce seroma.

Recipient Site Preparation

Internal mammary vessels exposed through intercostal space (rib-sparing) or partial rib cartilage resection (3rd or 4th). Rib-sparing approach preferred when possible (less donor site morbidity). Vessel preparation: ensure adequate length, identify branches for size match.

Microsurgical Anastomosis

Arterial: DIEA to IMA (end-to-end, typically 2-3 mm caliber). Venous: DIEV to IMV (end-to-end); sometimes coupler device used. Typically one artery and one or two veins. SIEV can be anastomosed to the cephalic vein or IMV tributary as secondary venous drainage (supercharging) if venous congestion is a concern. Ischemia time: target <60-90 minutes (shorter is better).

Flap Inset

Shape the flap to recreate breast mound: folding, trimming, contouring. Medial, lateral, and inferior pole shaping. Recreate the inframammary fold with fixation sutures. Temporary skin staples for positioning; final suturing after confirming perfusion.

Monitoring

Clinical monitoring every 1-2 hours for 48-72 hours: color, temperature, turgor, capillary refill, Doppler signal. Implantable Doppler (Cook-Schwartz): continuous venous signal monitoring; alarm if signal lost. External handheld Doppler checks as adjunct. ICG angiography intraoperatively to confirm perfusion before closing.

Bilateral DIEP Flap

Both DIEA pedicles harvested simultaneously or sequentially. Each hemiabdomen serves as one flap (Zones I and II primarily). Less tissue per flap than unilateral; may need full contralateral Zones I-III. Bipedicled (two separate pedicles) or single-pedicle with bilateral skin paddles (less common). Two-team approach reduces operative time.

Outcomes

Flap success rate: >97-99% in experienced centers. Patient satisfaction consistently high (BREAST-Q scores). Superior to implant reconstruction in irradiated patients. Long-term aesthetic outcomes improve over 1-2 years as flap settles. Donor site morbidity: abdominal contour improved (abdominoplasty effect), hernia/bulge rate 1-5%.

Complications

Flap-Related

Total flap loss (<1-3%): thrombosis (venous > arterial). Partial flap loss/fat necrosis (5-15%): perfusion-related; Zone III/IV territory. Venous congestion: requires re-exploration; medicinal leeches if salvage delayed. Arterial insufficiency: re-exploration and reanastomosis.

Donor Site

Abdominal bulge (5-10%) or hernia (1-5%). Seroma. Wound dehiscence. Umbilical necrosis or malposition.

General

DVT/PE (1-2%): chemoprophylaxis mandatory; SCDs. Infection. Hematoma.

<image>Intraoperative illustration showing the microsurgical anastomosis in DIEP flap breast reconstruction. The left panel shows the prepared recipient site with the internal mammary artery and vein exposed through a rib-sparing intercostal approach at the 3rd interspace, with rib cartilage above and below visible and the vessels isolated on vessel loops. The right panel shows the completed anastomosis with the DIEA sutured end-to-end to the IMA and the DIEV connected to the IMV using a venous coupler device. The DIEP flap is shown partially inset into the mastectomy pocket with its pedicle entering the chest through the intercostal space. Labels identify the IMA, IMV, DIEA, DIEV, venous coupler, intercostal space, and the flap with its perfusing perforator visible on the deep surface.</image>

Clinical Pearls

CTA is mandatory before DIEP flap surgery; it saves operative time, identifies the dominant perforator, and prevents intraoperative surprises (aberrant anatomy, absent perforators from prior surgery). Medial row perforators are preferred: shorter intramuscular course, easier dissection, and less muscle disruption. The SIEV should always be preserved during flap harvest as a bailout for venous drainage; if the flap shows any venous congestion after anastomosis, the SIEV can be supercharged to a cephalic vein or chest wall vein.

Intramuscular dissection should follow the muscle fibers longitudinally (splitting, not cutting) to minimize rectus abdominis denervation and postoperative weakness. Fat necrosis is the most common long-term complication; it is minimized by limiting the flap to well-perfused zones (I and II primarily) and using ICG angiography to identify poorly perfused tissue for excision before inset. Mesh reinforcement of the anterior rectus sheath closure significantly reduces the incidence of abdominal bulge and hernia, especially in bilateral cases.

References

• Allen RJ, Treece P. Deep inferior epigastric perforator flap for breast reconstruction. Ann Plast Surg. 1994;32(1):32-38.
• Blondeel PN. One hundred free DIEP flap breast reconstructions: a personal experience. Br J Plast Surg. 1999;52(2):104-111.
• Gill PS, Hunt JP, Guerra AB, et al. A 10-year retrospective review of 758 DIEP flaps for breast reconstruction. Plast Reconstr Surg. 2004;113(4):1153-1160.
• Granzow JW, Levine JL, Chiu ES, Allen RJ. Breast reconstruction with the deep inferior epigastric perforator flap: history and an update on current technique. J Plast Reconstr Aesthet Surg. 2006;59(6):571-579.
• Momeni A, Remington AC, Lee GK. A systematic review of complications and patient-reported outcomes in tissue expander/implant vs autologous breast reconstruction. J Plast Reconstr Aesthet Surg. 2015;68(2):162-171.
• Enajat M, Rozen WM, Whitaker IS, et al. Preoperative imaging for perforator flaps: a comparison of computed tomographic angiography and magnetic resonance angiography. Microsurgery. 2010;30(1):24-31.

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