Lecture on Skin Grafts and Flaps
Overview
- Skin grafting or flapping: Surgical transplantation of skin from donor to recipient site.
- Primary uses:
- Transplantation in extensive wounds, trauma, burns.
- Skin loss due to infection.
- Skin replacement after cancer removal.
Skin Graft
Definition
- Composed of epidermis and part of the dermis.
- Removed from blood supply and transferred to another site.
Uses
- Close wounds with good blood supply.
- Temporary closure for burns to allow healing without infection.
- Control infection.
- Close donor sites or large flap areas.
- Mucosal replacement in urethra/oral cavity.
Types of Grafts
- Autograft: From the same individual.
- Allograft (Homograft): From a different human.
- Xenograft (Heterograft): From another species.
Graft Types by Thickness
- Full Thickness: Contains epidermis and entire dermis; good for elasticity (e.g., over joints).
- Partial Thickness: Contains epidermis and part of dermis; associated with secondary contracture.
Contracture Types
- Primary Contracture: Immediate recoil due to elastin; beneficial for elasticity.
- Secondary Contracture: Contracture due to myofibroblasts; can cause hypertrophic scarring.
Survival Phases
- Serum Imbibition: First 24 hours; nutrient absorption by capillary action.
- Inosculation: Second 24 hours; establishment of vascular network.
- Revascularization: Third 24 hours; capillary "kissing" completes revascularization.
Graft Failure Causes
- Hematoma under graft.
- Infection.
- Inadequate immobilization.
- Poor blood supply or infection in wound bed.
- Incorrect application (e.g., upside down).
Mesh Graft
- Used for large defects or limited donor area.
- Made into mesh to cover large areas.
Flap
Definition
- Transplantation of tissue with its blood supply.
Uses
- Cover poorly vascularized recipient beds.
- Reconstruct full thickness structures (e.g., eyelids, ears).
- Operate through wound without failure.
- Functional muscle unit replacement.
Types by Location
- Local Flaps: From same site as defect.
- Advancement, Rotational, Transpositional.
- Regional Flaps: From same region.
- Distant Flaps: From different region.
Types by Blood Supply
- Random Flaps: No named artery.
- Axial Flaps: Named artery present.
- Subtypes: Island, Peninsular, Free.
Types by Content
- Skin, Muscle, Fasciocutaneous, Osteocutaneous, Mixed.
Flap Failure Causes
- Intrinsic: Inadequate blood supply, arteriovenous shunts.
- Extrinsic: Infection, hypotension, hematoma, smoking.
Monitoring Viability
- Clinical tests: Color, temperature, capillary refill, etc.
- Chemical: Fluorescein dye.
- Instrumental: Ultrasound, photoplethysmography, tissue pH, PO2, PCO2.
Conclusion
- Importance of correct application and monitoring.
- Different uses and types for grafts and flaps.
Remember to watch the video for more information and support by subscribing!