Free flap classifications Flashcards
How does the Cormack and Lamberty classification guide flap selection for a specific hand defect?
It categorizes flaps by vascular reliability, size, and mobility, enabling surgeons to match flap properties—like Type C’s robust supply—to defect needs, optimizing hand reconstruction outcomes.
What defines the vascular supply of a Type A fasciocutaneous flap in the Cormack and Lamberty classification?
Type A flaps are supplied by multi**ple small perforators entering at the base, independent of a single named vessel. This diffuse vascularity suits them for small, local defects in hand surgery, such as dorsal wounds, due to their simplicity and reliability.
What is an example of a Type B fasciocutaneous flap used in hand surgery, and how is its vascular supply characterized?
**The lateral arm flap is a Type B flap, relying on a single perforator from the posterior radial collateral artery. **
Its single-vessel supply requires precise preservation during harvest, making it ideal for thin, pliable coverage like the dorsum of the hand.
How does the vascular anatomy of a Type C flap differ from a Type B flap according to Cormack and Lamberty?
**A Type C flap features multiple perforators from a named artery, unlike the Type B flap’s single perforator. **
This robust blood supply enhances reliability, making Type C flaps suitable for larger or more complex hand reconstructions.
What unique component does a Type D flap include, and how does it enhance its utility in hand surgery?
Type D flaps incorporate muscle or omentum with fasciocutaneous tissue.
This composite design provides bulk and vascularity, ideal for reconstructing complex defects.
How does the arc of rotation differ between Type A and Type C flaps, and what does this mean for hand surgery?
Type A flaps have a limited arc due to multiple small perforators, suiting local defects, while Type C flaps, with multiple perforators from a named artery, offer a broader arc, enabling coverage of distant hand sites.
What anatomical factors must be considered when harvesting a Type C flap like the radial forearm flap for hand reconstruction?
Preserve the radial artery perforators along the intermuscular septum, ensure adequate pedicle length, and assess donor site morbidity (e.g., sensory loss), critical for successful hand defect coverage.
What role does the subdermal plexus play in the viability of Type A flaps?
The subdermal plexus supplements the multiple small perforators, enhancing blood supply and ensuring flap survival, particularly in small hand flaps like V-Y advancements.
How is the posterior interosseous flap classified by Cormack and Lamberty, and what is its vascular basis?
It’s a Type C flap, supplied by multiple perforators from the posterior interosseous artery along the septum between extensor carpi ulnaris and extensor digiti minimi, ideal for hand coverage.
How does donor site morbidity compare between Type A and Type C flaps in hand surgery?
Type A flaps, often local, have minimal morbidity, while Type C flaps, involving larger vessels, may cause sensory or aesthetic issues, impacting hand surgery planning.
What preoperative steps are essential before opting for a Type B (cormack) flap in hand reconstruction?
Doppler ultrasound confirms the single perforator’s presence and caliber, alongside vascular status assessment, ensuring reliability for hand flap success.
How is the first dorsal metacarpal artery flap classified, and what supplies it?
It’s a Type B flap, powered by a single perforator from the first dorsal metacarpal artery (radial artery branch), useful for small hand defects.
What limits Type A flaps in addressing large hand defects?
Their reliance on small perforators and the subdermal plexus restricts size and mobility, making them inadequate for large hand reconstructions needing robust supply.
What is a Type I muscle flap according to the Mathes-Nahai classification?
A muscle flap with a single dominant vascular pedicle that supplies the entire muscle.
Examples: Gastrocnemius, Tensor fascia lata, Abductor digiti minimi. Note: Ideal for free flaps due to a single, reliable pedicle.
What is a Type II muscle flap?
A muscle flap with one dominant pedicle and additional minor pedicles. The minor pedicles cannot sustain the entire flap if the dominant pedicle is sacrificed.
Examples: Gracilis, Soleus, Trapezius. Note: The dominant pedicle is typically used for free flaps, as minor pedicles are insufficient alone.
What is a Type III muscle flap?
A muscle flap with two dominant pedicles, each capable of supplying the entire muscle independently.
Examples: Rectus abdominis, Gluteus maximus. Note: Offers versatility due to dual blood supply, allowing greater arc of rotation.
What is a Type IV muscle flap?
A muscle flap with multiple segmental pedicles, each supplying only a small portion of the muscle.
Examples: Sartorius, Tibialis anterior. Note: Less reliable for large flaps due to limited supply per pedicle.
What is a Type V muscle flap?
A muscle flap with one dominant pedicle and secondary segmental pedicles that can sustain the entire flap if the dominant pedicle is sacrificed.
Examples: Latissimus dorsi, Pectoralis major. Note: Highly versatile; secondary pedicles often enter from the opposite end, enabling distally based flaps.
Why is a Type V muscle flap versatile?
It can be based on either the dominant pedicle or the secondary pedicles, allowing flexibility in arc of rotation and use as a distally based flap.
Examples: Latissimus dorsi, Pectoralis major.
What is the main limitation of Type IV muscle flaps?
Each segmental pedicle supplies only a small muscle segment, making large flaps less reliable due to potential vascular insufficiency.
Examples: Sartorius, Tibialis anterior.
Give an example of a muscle that can be used as a free flap and its Mathes-Nahai type.
Gracilis muscle, Type II. When used as a free flap, it is supplied by its dominant pedicle, as the minor pedicles are insufficient alone.
How does the Mathes-Nahai classification help in choosing a muscle flap?
It predicts:
- Vascular reliability: Based on pedicle dominance and number.
- Arc of rotation: Influenced by pedicle location and number.
- Skin territory: Viability when used as a musculocutaneous flap.
- Suitability: For techniques like free flaps or distally based flaps.
What is the key difference between Type II and Type V muscle flaps?
In Type II, minor pedicles cannot sustain the entire flap if the dominant pedicle is sacrificed. In Type V, secondary pedicles can sustain the entire flap independently.
Examples: Type II - Gracilis; Type V - Latissimus dorsi.
What is a mnemonic for remembering examples of each Mathes-Nahai type?
“Ten Graceful Glutes Sat on Latrines”:
- Ten: Tensor fascia lata (Type I)
- Graceful: Gracilis (Type II)
- Glutes: Gluteus maximus (Type III)
- Sat: Sartorius (Type IV)
- Latrines: Latissimus dorsi (Type V)
