Defying Consensus: Correct Sizing of Full-Thickness Skin Grafts

April 2012 | Volume 11 | Issue 4 | Original Article | 520 | Copyright © April 2012

Isaac Zilinsky MD,a,b* Nimrod Farber MD,b* Oren Weissman MD,b Hadar Israeli MD,b Josef Haik MD,b Noam Domniz MD, b Eyal Winkler MD b

a Mohs Micrographic Surgery Unit b Department of Plastic and Reconstructive Surgery Chaim Sheba Medical Center, Tel Hashomer, Israel The Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel *I. Zilinsky and N. Farber contributed equally to this work.

Abstract
Background: Full-Thickness skin grafts are routinely used to reconstruct defects throughout the body. When planning the size of the graft, the surgeon usually copies a template from the defect and measures the graft to fit its full dimensions. This may lead to an oversized graft, resulting an unaesthetic outcome.
Objective: To evaluate discrepancy in size between the excised full-thickness skin and the excision (donor) site.
Methods: Data from 20 cases of full-thickness excisions was reviewed and analyzed.
Results: There was a considerable difference in length of both the short and long axes between the excised full-thickness skin and the excision site.
Conclusions: The initial size of a full-thickness skin graft should be smaller than the defect it is planned to cover.

J Drugs Dermatol. 2012;11(4):520-523.

INTRODUCTION

Skin grafts are frequently used to reconstruct defects after extirpation of lesions on the face, and are classified as either a full-thickness skin graft (FTSG) or a split-thickness skin graft (STSG), according to the amount of dermis involved.1 Compared with STSGs, full thickness grafts include the entire dermis and are better suited for reconstruction of facial defects because they provide closer color, texture, and thickness matches. 1-3 Traditionally, the size of the FTSG is based on a template from the defect or slightly larger.1-2However, when examining long-term results it is not uncommon to find unsightly puckering of the mature graft beyond the borders of the defect (Figure 1). We believe that this deformity represents a misconception of basic reconstructive principles, mainly failure to recognize the naturally occurring wound contraction during healing and incorrectly planning an oversized graft. This notion is easily demonstrated by placing excised full thickness skin back in place immediately after it has been harvested: the wound margins drift apart while primary contraction causes recoiling and shrinkage of the excised skin, leading to a considerable discrepancy in size (Figures 2 and 3).

METHODS

Data from twenty cases of full thickness skin excisions was reviewed and analyzed. All excisions were carried out according to the principles of relaxed skin tension lines.4-5 The long and short axes of both the excised skin and the open excision site were measured immediately after harvesting. Donor sites for FTSG were primarily sutured without complications.

RESULTS

Patients were aged 29 to 81 years. Excision sites were categorized into 3 groups according to their anatomic region: half of the cases were located on the face (eg, post and pre-auricular) and 25% were located on either the extremities (eg, arms & thighs) or torso (eg, back & abdomen) (Table 1). The minimal average discrepancy between the excision site and the excised skin was 16%, and increased to 32% when examining the short axis. This finding was true for all three groups. The average discrepancies regarding the short axes were at least double than that of the long axes. This trend was most prominent on the extremities (Chart 1).