Overview
Definition:
Skin graft meshing is a technique used to expand the surface area of a harvested skin graft, typically a split-thickness skin graft (STSG), by creating a series of small perforations
These perforations allow the graft to be stretched, covering a larger wound area than its original size
The degree of expansion is determined by the meshing ratio
Full-thickness skin grafts (FTSGs) are generally not meshed due to their tendency to contract and compromise the viability of underlying tissues when perforated.
Epidemiology:
Meshing of skin grafts is a common practice in burn centers and reconstructive surgery units globally
It is particularly crucial in managing large surface area burns where the availability of donor sites is limited
The incidence of large burns requiring meshed STSG varies geographically and is influenced by factors like fire safety regulations, industrial accidents, and socioeconomic conditions.
Clinical Significance:
Skin graft meshing is vital for maximizing wound coverage with limited donor tissue, significantly impacting patient outcomes in burns and large traumatic defects
It allows for earlier wound closure, reduces the risk of infection, promotes healing, and can improve the cosmetic and functional results
Understanding the optimal meshing ratios is critical for graft survival and minimizing complications, making it a key area for surgical residents preparing for DNB and NEET SS examinations.
Indications And Contraindications
Indications For Meshing:
Large superficial or partial-thickness burns
Traumatic skin defects where donor site is limited
Areas requiring extended coverage with a single graft
Infected wounds where drainage through the graft is desired
Post-excision defects of large lesions.
Indications For Non Meshing:
Full-thickness skin grafts
Small, localized defects where graft size is adequate
Grafting over vital structures like joints or facial areas where contraction is a concern
Areas where cosmetic outcome is paramount and minimal scarring is desired.
Contraindications To Grafting:
Uncontrolled infection at the recipient site
Non-viable recipient bed
Systemic compromise of the patient
Exposed bone or tendon without adequate soft tissue coverage for graft adherence
Active hemorrhage.
Meshing Ratios And Types
Meshing Ratios:
1:1 (Unmeshed)
1:1.5 (Mild expansion)
1:2 (Moderate expansion)
1:3 (Significant expansion)
1:4 or higher (Aggressive expansion)
The ratio indicates the number of times the graft area is expanded
For example, a 1:3 ratio means a 10x10 cm graft can cover up to 30x10 cm or 10x30 cm.
Types Of Meshers:
Stationary meshers: The dermatome moves over a stationary mesh drum
Reciprocating meshers: The mesh drum moves against a stationary cutting blade
Automated meshers: More advanced devices offering precise control.
Factors Influencing Ratio Choice:
Size and depth of the defect
Availability of donor site
Vascularity of the recipient bed
Presence of infection
Patient's age and general health
Desired aesthetic outcome.
Surgical Technique And Graft Care
Donor Site Harvest:
Typically harvested using a dermatome at a predetermined thickness (e.g., 0.012-0.018 inches for STSG)
The donor site is often treated with topical agents and dressed to promote re-epithelialization.
Meshing Procedure:
The harvested graft is passed through the mesher
The pattern of perforations depends on the type of mesher used
Care must be taken to avoid tearing or excessive trauma to the graft.
Recipient Site Preparation:
Thorough debridement of necrotic tissue, granulation tissue, or foreign material
Hemostasis is critical
The recipient bed should be well-vascularized
Appropriate wound dressings are applied.
Graft Application And Dressing:
The meshed graft is carefully laid onto the recipient bed, ensuring intimate contact
It is secured with sutures, staples, or fibrin glue
A non-adherent dressing (e.g., Adaptic, Mepitel) is applied directly over the graft, followed by absorbent gauze and a bolster or compressive dressing to maintain graft-bed contact and prevent shear forces.
Complications Of Meshed Grafts
Early Complications:
Graft shear or displacement
Hematoma or seroma formation
Infection of the wound or graft
Inadequate graft adherence leading to desiccation
"Pinhole" graft failure (failure at individual meshing sites).
Late Complications:
Excessive scarring and contracture, particularly with higher meshing ratios
Irregular pigmentation
Persistent pruritus
Appearance of "spiderweb" scarring due to the mesh pattern
Limited mobility in grafted areas, especially over joints.
Prevention And Management:
Meticulous surgical technique with good hemostasis
Secure graft fixation
Appropriate postoperative dressings and immobilization
Early recognition and treatment of infection
Use of lower meshing ratios for aesthetically sensitive areas or over joints.
Key Points
Exam Focus:
Understand the different meshing ratios and their implications for graft take and wound coverage
Differentiate indications for meshed vs
unmeshed grafts
Recall common complications and their management
Knowledge of dermatome settings for STSG harvest is crucial.
Clinical Pearls:
For large defects, consider sheet grafting small areas and meshing larger ones
Always ensure intimate contact between graft and recipient bed
Over-grafting with a lower meshing ratio is often safer than aggressive meshing of a compromised graft
Close monitoring in the first 48-72 hours post-op is critical for graft survival.
Common Mistakes:
Using excessively high meshing ratios on compromised beds
Inadequate debridement of the recipient site
Poor hemostasis leading to graft hematoma
Insufficient graft adherence due to improper dressing
Neglecting to monitor for early signs of graft failure or infection.