Optimizing Intraflap Anastomosis of Conjoined Bilateral DIEP Flaps

Plastic and Reconstructive Surgery, Sept 2024

Key take aways:

• Intraflap anastomosis allows for larger flaps with only one set of recipient vessels in the chest. Perforator and recipient vessel selection is critical.

• The hemi-abdomen with "dominant" perforator serves as the recipient flap

  • Type 1 branching pattern: the superior continuation of the deep epigastric vessels serves as the intraflap recipient

    • Favor more caudal perforator to improve the caliber of the superior continuation

  • Type 2 & 3: the bifurcation or large side branch serves as the intraflap recipient

  
  

Background

Conjoined bilateral DIEP flaps with intraflap anastomosis allow maximal use of abdominal tissue for unilateral breast reconstruction, especially in cases requiring large volume or with limited abdominal bulk. However, anatomical variation in DIEA branching complicates consistent execution of this technique.

Objective

To develop an algorithmic approach to reliably perform intraflap anastomosis in conjoined bilateral DIEP flap reconstructions, using patient-specific CTA planning to guide pedicle selection and vessel configuration.

Methods

• Design: Retrospective single-surgeon series of 201 consecutive cases (2009–2023).

• Inclusion: Breast reconstructions using conjoined bilateral DIEP flaps

• Planning: Preoperative CTA was used to assess DIEA branching (Types 1–3) and perforator anatomy.

• Execution: ICG angiography assessed intraoperative perfusion. Primary pedicle selected based on recipient vessel caliber and branching type.

• Outcome Measures: Alignment of plan vs. intraoperative execution, complications, and flap inset ratio (weight of final flap/weight of harvested flap).

Results

• Flap Type: 100% completed using intraflap anastomosis (no conversions).

• Branching Types: Type 1 (49%), Type 2 (38%), Type 3 (13%); most common combination: Type 1–Type 2 (33%).

• Pedicle Configuration:

  • Type 1: Caudal perforators favored for larger superior continuations.

  • Type 2 & 3: Side branches used as recipient vessels.

  • Smaller secondary veins matched to smaller vena comitants to avoid size mismatch.

• Plan Deviations: 28 cases (14%), primarily to secure better-caliber vessels or optimize perfusion.

• Complications:

  • Venous congestion: 4 cases (2%), all salvaged

  • Fat necrosis ≥3 cm²: 8%

  • Delayed wound healing: 8.5% (flap), 11.4% (donor)

  • No flap losses

• Inset Ratio: 0.86 ± 0.10

Conclusion

A CTA-driven, anatomy-specific algorithm for selecting recipient vessels enables consistent and safe use of intraflap anastomosis in conjoined bilateral DIEP flaps. High success, low complication rates, and strong plan-execution concordance (>85%) support the technique's reliability.

Clinical Implications

Surgeons can confidently adopt conjoined bilateral DIEP flaps with intraflap anastomosis by:

• Prioritizing recipient vessel caliber over perforator size

• Understanding DIEA branching patterns to guide pedicle choice

• Leveraging CTA and ICG angiography for precise planning and perfusion validation