V-to-Y Conversion Flaps

Occasionally we run into lacerations in the ED involving a large tissue flap avulsion.  These are usually the injuries that catch the eyes of nurses and staff, if for nothing else but for the gore factor.  Here’s one I treated just a few months ago:

A large, V-shaped laceration on the forearm of a carpenter.

The large, V-shaped rent through the forearm of this patient was pretty interesting to treat…but not for the guts/gore factor–rather, I was interested in figuring out how to achieve a tension-free closure that would allow this self-employed carpenter to get back to work as soon as safely possible.

This laceration, like some you may have seen before, had so much tension that I could not pull the wound edges together in order to close it in its original configuration.  And, even in situations where you can manage to pull the vertex of the flap to the opposite side of the wound, this is generally not optimal–that excessive tension on the flap edge during the healing process can cause compromise of the blood supply which can cause ischemia to the healing tissue, which in turn makes that flap edge more likely to become necrotic and/or infected. I saw this as an opportunity to get creative for the good of the patient.  The video below outlines the problem and the solution, and the text below describes the technique in greater detail.

V-to-Y Conversion: A tension relieving trick for the ED

If you come across a V-shaped laceration with a corner, where trying to oppose the apex with a corner stitch would produce excessive tension on the tip of the flap, consider this closure method instead:

(1) Undermine each of the wound edges to give maximal play with the margins of the wound.  Usually the flap edge is already pretty mobile, and it’s the fixed edges that need to be loosened from subcutaneous connective tissue anchoring.  In the cartoon depiction below, the “Flap” and the “Apex” are labelled for clarity.

A V-shaped laceration. For reference purposes, the “Flap” edge and “Apex” of the wound are labelled. The flap tip and apex are not easily opposed due to tension.

(2) Next, use a paper ruler to measure points of equal distance starting from the apex and following along the sides of the wound.  The length of these points will be the points of the new corner being created, and their length can be determined based on the amount of tension that is to be removed from the flap edge.  It is best to measure and then mark these points precisely, with a surgical marker, rather than just trying to “eyeball” it, which can lead to unequal wound edge lengths upon final closure.  The points here are marked in green.

Measure points of equal distance from the apex on both sides of the wound edge.

(3) Next, a corner stitch is applied. Enter with the suture needle on either side of the base where the green “X” is.  Exit in the center of the wound bed, drive the suture in a half-buried fashion through the vertex of the flap edge (here shown in dotted purple), then exit at the site of the second green arrow.

A corner stitch, using the previously marked points on the base and the flap edge, is placed.

(4)  When the suture is tied off, the shape of the wound is transformed from its original “V” to a “Y” shaped configuration.  This lessens the “pull” on the flap edge, thus there is less risk of strangulation of the already compromised blood supply to the flap edge.

Tying the suture transforms the wound shape from a “V” to a “Y,” with considerably less tension on the flap edge.

A few side notes on this technique:

(a) This is NOT the same thing as the plastic surgeon’s “V-to-Y advancement flap.”  THAT is a wound coverage technique which actually involves excision of a flap of tissue to cover an area of exposed muscle or tissue, such as with a burn or a decubitus ulcer.  I would NOT recommend an Emergency Physician uses flap excision to cover a wound, as this requires a more intricate knowledge of the underlying vascular supplies of the skin. The technique I describe above is derived from plastic surgery teaching, so don’t get them confused.

(b)  Even the most carefully performed closure using this technique may result in formation of wound “dog ears,” which refers to wound edges of unequal length as the skin is closed.  Not to fear.  A description of how to correct dog ears is on this website.

(c)  Use undermining and deep suture placement in a layered closure in conjunction with this method.  This optimizes the chances of a cosmetic, tension-free repair.

Give it a try, and give me your comments on the technique.  Happy sewing!