What is the primary blood supply to a fasciocutaneous (fasciocutaneous) trunk flap of the abdomen?

Primary Blood Supply to Fasciocutaneous Trunk Flap of the Abdomen

The primary blood supply to a fasciocutaneous trunk flap of the abdomen is provided by perforator branches from the deep inferior epigastric artery (DIEA), which arises from the external iliac artery. 1

Vascular Anatomy of Abdominal Fasciocutaneous Flaps

• The deep inferior epigastric artery (DIEA) is the main source vessel providing blood supply to the lower abdominal wall through its perforator branches 1
• The DIEA has a consistent origin from the external iliac artery, making this vessel reliably identifiable 1
• The perforator branches of the DIEA can be classified into three types based on their branching pattern: single trunk (type 1), bifurcating trunk (type 2), and trifurcating trunk (type 3) 1
• These perforator arteries are further divided into intramuscular, subfascial, and subcutaneous segments as they course through the abdominal wall 1

Distribution and Characteristics of DIEA Perforators

• An average of 5.4 large perforators (>0.5 mm in diameter) supply the anterior abdominal wall per hemiabdomen 2
• The lateral division of the DIEA provides more dominant and numerous perforators (80% of cases) compared to the medial division (20% of cases) 2
• Perforators are predominantly located in the area lateral and below the umbilicus, with an average distance of 4 cm from the umbilicus 2
• The DIEA is typically associated with two venae comitantes in 90% of cases 2

Medial vs. Lateral Row Perforators

• Fundamental differences exist between medial and lateral row perforators 3:
  • Medial row perforators are larger (average 1.3 mm vs. 1.0 mm for lateral perforators) 3
  • Medial row perforators are more likely to ramify toward the contralateral hemiabdomen (98% of cases vs. 2% for lateral perforators) 3
  • This makes medial row perforators generally preferable for flap design when possible 3

Perforator Angiosome Concept

• The "perforator angiosome" concept describes the territory supplied by a single perforator vessel 3
• This is particularly important in DIEA perforator flap design, where only selected perforators are included in the flap 3
• The ideal perforator should be of large caliber and medially located within the flap with an extended vascular territory beyond the midline to provide optimal perfusion 1

Clinical Implications

• The unpredictable orientation and course of DIEA perforators may result in more random than axial blood supply in some flaps 4
• Preoperative imaging (CT angiography or MR angiography) is recommended to map the perforators and their branches, leading to reduced operative time and increased flap reliability 1
• Understanding the perforator anatomy helps in selecting the "best" perforator based on size, location, and intramuscular course 1
• A short intramuscular course allows for successful dissection of the perforator 1

Additional Vascular Considerations

• Superior epigastric artery (SEA) perforators are more consistent in morphology and orientation compared to DIEA perforators 4
• SEA perforators typically pierce the rectus sheath within 4 cm of the costal margin 4
• Preservation of SEA perforators during abdominoplasty can improve abdominal wall perfusion 4

Understanding the vascular anatomy of the DIEA and its perforators is crucial for successful design and harvest of fasciocutaneous flaps from the abdominal region, with significant implications for patient morbidity, mortality, and quality of life outcomes.