Split-Thickness Skin Graft (STSG)
see example For more images and videos of techinque of harvest, care of donor site: Case Example Split Thickness Skin Graft STSG Zimmer Dermatome
|title||Case Example Split Thickness Skin Graft STSG Zimmer Dermatome|
see also: Skin Graft Donor Site Care
return to: Reconstructive Procedures Protocols
- General Considerations
- Reconstruction of a skin defect
- Reconstruction of non-skin epithelial defect
- Sinus (as after maxillectomy)
- Laryngeal defect or urethral stricture (see better alternative: Buccal mucosal graft)
- Consider 'reconstructive ladder': healing by secondary intention/primary closure/flap reconstruction/distal flap
- Cadaveric allografts
- Processed collagen: Alloderm
- Porcine xenograft
- Pertinent anatomy/ physiology
- Skin anatomy
- A STSG consists of the epidermis and part of the dermis (see Full thickness skin graft: consists of epidermis and entire dermis)
- The reticular layer of dermis contains epidermal appendages (sebaceous glands, sweat glands, hair follicles), which are lined with epithelial cells that have the potential for division and differentiation
- These structures are critical for skin graft healing. Injuries to these structures (eg. Cauterization, Accutane treatment) increase the risk of poor healing
- Phases of skin-graft survival
- Imbibition- graft absorbs (imbibe) nutrients from underlying recipient bed
- Inosculation- blood vessels in skin graft grow to meet the vessels (inosculate = kiss) of the recipient bed
- Neovascularization- new blood vessels from between the graft and recipient tissues
- STSG vs. full thickness skin grafts (FTSG)
- STSG- better survival but more contraction and potential pigmentation change. Donor site heals through re-epithelialization, which can cause discomfort.
- FTSG- higher metabolic needs of thicker graft causes higher rates of flap failure, but are a better color match and contract less. Donor site is usually closed primarily.
- Donor site considerations
- Any part of the body may be used, but an area that can be hidden by clothing and minimize discomfort is usually chosen.
- Posterolateral thigh is a common site as it provides a large, relatively flat surface area for harvest
- Free flap- especially useful if the flap is placed intraorally or subcutaneously, de-epithelializing the skin paddle eliminates donor site pain because the flap skin is insensate
- Dermatome (eg. Zimmer ) with blade and blade guards
- Alternatively, the harvest may be performed freehand using a scalpel
- Vasocontrictive or thrombotic agent – eg. thrombin, epinephrine
- #15 scalpel
- Tongue depressor, or other straight, rigid instrument
- Mineral oil
- The dermatome is fitted with the appropriate width blade guard for the desired size of skin graft. The thickness is typically set to 0.015 - .018 inches (accommodates the width of a #15 blade) for an intermediate-thickness STSG.
- Mineral oil may be applied to the blade to facilitate lifting the graft off the blade later
- Adequate local/regional or general anesthesia is given.
- The donor site is cleaned and any residual prep solution is wiped off to allow the dermatome to glide over the skin smoothly.
- Lubricating the skin with mineral oil also helps
- Turn the dermatome on, then holding it at approximately 30 degree angle to the skin surface, engage the skin with a gentle downward pressure and advance the dermatome forward in a steady, continuous motion. Various techniques can be employed to provide traction on the skin and facilitate smooth advancement:
- The surgeon pulls back on the skin behind the dermatome while an assistant flattens and provides countertraction in front of the dermatome using a tongue depressor, metal ruler, or other straight, rigid instrument
- An assistant may alternatively grasp the skin just beyond the borders of the graft using towel clamps, pulling in opposite directions to stretch the skin
- When the appropriate length is reached, harvest is terminated.
- The dermatome can be tilted up and then lifted off the skin to cut the distal edge of the graft
- The dermatome can be stopped while still in contact with the skin, and the final edge is cut using a scalpel
- The graft is placed in saline until use
- Gauze/Telfa soaked with a vasocontrictive/thrombotic agent (eg. thrombin, epinephrine) is applied to the donor site
- Do not do this if the graft is harvested from free flap skin, to avoid possible vascular compromise
- The STSG may be meshed before inset, or “pie-crusted” after inset to allow fluid to escape rather than accumulate below the graft as a hematoma/seroma
- Care should be taken when placing the graft to place it with the dermal side, typically shinier and whiter, down and so there is neither excessive stretching or wrinkling
- The STSG is usually secured to the recipient site by using 4 corner sutures, then a running suture around the periphery, both with chromic gut. 4-0 chromic on RB-1 needle is ideal.
- Additional tacking sutures may be placed within the graft to increase adherence to the underlying tissue
- Post-operative care
- Post-op care regimen varies based on surgeon preference
- The graft dressing should provide uniform pressure to prevent shearing of the graft and prevent hematoma/seroma formation
- Wound-vac, if it can be contoured to hold suction on the wound, is useful
- The dressing is usually removed after 7 days, graft take assessed, and additional dressing selected accordingly (eg. Bacitracin, wet-to-dry)
- Donor site dressing options include open, semiopen, occlusive, semiocclusive, and biological (eg. Tegaderm, stapled Allevyn)
- See Skin Graft Donor Site Care protocol
- Potential complications: donor site pain, fluid loss, hypertrophic scarring, undesirable pigmentation, prolonged healing
- Akan M, Yildirim S, Misirlioğlu A, Ulusoy G, Aköz T, Avci G. An alternative method to minimize pain in the split-thickness skin graft donor site. Plast Reconstr Surg. 2003 Jun;111(7):2243-9.
- Kim PD, Fleck T, Heffelfinger R, Blackwell KE.Avoiding secondary skin graft donor site morbidity in the fibula free flap harvest.Arch Otolaryngol Head Neck Surg. 2008 Dec;134(12):1324-7.
Hoffman HT, LaRouere M. A Simple Bolster Technique for Skin Grafting. Laryngoscope,99(5):558-59, 1989.