Overview

Definition:
-DIEP (Deep Inferior Epigastric Perforator) flap is a free flap breast reconstruction technique that utilizes abdominal skin and subcutaneous tissue, powered by perforating vessels from the deep inferior epigastric artery (DIEA) and vein (DIEV)
-Recipient vessel selection is crucial for successful flap anastomosis and perfusion.
Epidemiology:
-Autologous breast reconstruction, including DIEP flaps, is increasingly common
-The choice of recipient vessels impacts operative time, success rates, and potential for complications
-Patient anatomy, prior surgeries, and surgeon preference guide vessel selection.
Clinical Significance:
-Optimal recipient vessel selection is paramount for ensuring adequate blood supply to the free flap, thereby minimizing the risk of flap failure, necrosis, and associated morbidity
-It directly influences the long-term aesthetic and functional outcomes of breast reconstruction.

Indications Contraindications

Indications:
-Breast reconstruction following mastectomy (immediate or delayed)
-Suitable for patients with adequate abdominal tissue and no contraindications to abdominal surgery or microsurgery
-Patients seeking a natural breast mound with autologous tissue.
Contraindications:
-Previous extensive abdominal surgery (e.g., multiple scars compromising perforator blood supply)
-Significant abdominal wall weakness or hernia
-History of radiation to the chest wall impacting recipient vessel viability
-Uncontrolled comorbidities that preclude major surgery
-Inadequate perforator anatomy identified preoperatively.

Preoperative Assessment

Patient History:
-Detailed surgical history, especially abdominal and thoracic surgeries
-History of smoking, diabetes, hypertension, and medications (e.g., anticoagulants, steroids) that affect vascular health
-Assessment of body mass index (BMI).
Physical Examination:
-Abdominal examination to assess skin laxity, subcutaneous tissue thickness, and presence of scars
-Palpation for abdominal wall integrity
-Examination of the chest wall for suitability of recipient vessels, including presence of palpable arteries and veins.
Imaging:
-Computed tomography angiography (CTA) or Doppler ultrasound is essential to map perforator anatomy, measure vessel diameters, and assess their origin from the DIEA/DIEV
-This helps in planning and confirming the suitability of recipient vessels
-Preoperative marking of perforators based on imaging is critical.
Recipient Vessel Considerations:
-Availability of a suitable artery and vein of adequate size (typically >1.5-2 mm diameter) and quality
-Proximity of the chosen vessels to the flap pedicle to minimize tension on the anastomosis
-Absence of significant atherosclerosis or previous venous stasis in the selected vessels.

Recipient Vessel Options

Chest Wall Vessels:
-Internal mammary artery (IMA) and vein: A common choice, especially if the DIEA is compromised or in patients with prior abdominal surgery
-Originates from the subclavian artery
-Requires careful dissection and ligation of branches
-Provides robust arterial supply.
Thoracodorsal Vessels:
-Thoracodorsal artery and vein: An alternative option, originating from the axillary artery
-Often used when IMA is not ideal or unavailable
-May require longer pedicle dissection.
Intercostal Vessels:
-Intercostal arteries and veins: Less commonly used due to smaller caliber and potential for collateral formation
-May be considered in select cases when other options are exhausted.
Axillary Vessels:
-Axillary artery and vein: Can be used, particularly if the thoracodorsal vessels are not suitable
-Requires meticulous dissection to avoid injury to surrounding nerves and structures.

Anastomosis Technique

Arterial Anastomosis:
-Suture of the flap artery (DIEA or its branches) to the selected recipient artery
-Typically performed using fine non-absorbable sutures (e.g., 8-0 or 9-0 nylon)
-Careful handling to avoid intimal damage and kinking
-Location of anastomosis should be free of tension and ideally superior to the venous anastomosis.
Venous Anastomosis:
-Suture of the flap vein(s) (DIEV or venae comitantes) to the recipient vein(s)
-Usually performed using 7-0 or 8-0 non-absorbable sutures
-Two-vein anastomosis is often preferred to enhance venous outflow and reduce congestion risk
-Anastomosis should be performed inferior to the arterial anastomosis to facilitate venous drainage against gravity.
Technical Considerations:
-Meticulous hemostasis is critical
-Use of loupes or microscope is mandatory
-Adequate vessel length without tension is crucial
-Vessel preparation includes adventitial stripping where appropriate
-Flow assessment (e.g., Doppler probe) post-anastomosis is essential
-Patency is confirmed by capillary refill and venous filling.

Postoperative Care Monitoring

Flap Monitoring:
-Continuous monitoring for flap viability using clinical assessment (color, capillary refill, turgor) and Doppler ultrasound to detect arterial inflow and venous outflow
-Regular checks (e.g., every hour for the first 24-48 hours).
Anticoagulation Management:
-Prophylactic anticoagulation (e.g., low-molecular-weight heparin) may be used, especially in cases with suboptimal vessel caliber or flow
-Avoidance of aspirin or other antiplatelets unless specifically indicated and managed carefully due to bleeding risk.
Management Of Complications: Early detection and management of venous congestion (e.g., by needle decompression, leech therapy, or re-exploration) or arterial compromise (e.g., thrombectomy and re-anastomosis).
General Postoperative Care: Pain management, hydration, early mobilization, and monitoring for general surgical complications like infection, bleeding, and DVT.

Complications

Early Complications:
-Flap thrombosis (arterial or venous)
-Venous congestion
-Hematoma formation
-Wound dehiscence
-Infection
-Seroma
-Partial or complete flap necrosis.
Late Complications:
-Fat necrosis
-Granuloma formation
-Scarring
-Asymmetry
-Poor aesthetic outcome
-Chronic pain
-Donor site morbidity (e.g., hernia, bulging).
Prevention Strategies:
-Meticulous surgical technique, adequate flap perfusion, careful recipient vessel selection, judicious use of anticoagulation, aggressive flap monitoring, and prompt management of any signs of compromise
-Patient selection and preoperative assessment are key.

Key Points

Exam Focus:
-Understanding the anatomical basis of recipient vessels and their relative advantages/disadvantages
-Knowledge of factors influencing vessel selection
-Recognition of potential complications and their management
-Key diagnostic modalities for vessel assessment (CTA, Doppler).
Clinical Pearls:
-Always have a backup plan for recipient vessels
-Never compromise pedicle length excessively
-Two-vein anastomosis improves venous outflow and safety margins
-Intraoperative Doppler assessment is crucial for confirming flow
-Thorough preoperative imaging is non-negotiable.
Common Mistakes:
-Selecting vessels of inadequate caliber or quality
-Creating tension on the anastomosis
-Insufficient flap monitoring postoperatively
-Failure to identify or manage venous congestion promptly
-Over-reliance on a single recipient vessel option without considering alternatives.