When I show emergency physician colleagues the inverting horizontal mattress suture technique, most everyone finds it interesting; but most also have the question:

When would I ever use this?

In this post I feature two quick videos of real situations in the emergency department where this little technique made a big difference.

Remember, the typical simple interrupted suture, vertical mattress suture, or horizontal mattress suture is meant to evert tissue or at least allow it to lay flat; inversion is rarely an intentional, desired effect. But there are rare occasions where inversion is helpful. Typically, the situation is when you are re-creating a natural crease, or working within an existing crease that’s hard to access.

The first video features closure of a laceration at the lateral canthus of the eye. This area features a natural crease, and the act of intentionally (or accidentally) everting would likely not lead to an ideal cosmetic outcome.

Use of the inverting horizontal mattress suture for closure of a small laceration along the lateral canthus of the eye.

The second video feature is an attempt to tack down the posterior portion of an ear. I actually supervised a resident to whom I was teaching this technique, and she was using it for the first time. While she ultimately performs the technique perfectly, you’ll notice some hesitation as she tries to determine how to place the second throw. This is actually very common for learners of this technique.

Use of the inverting horizontal mattress suture on the posterior pinna of the ear.

The reason for this has to do with overcoming the “muscle memory” that comes along with familiarity. This seasoned third-year resident certainly already knew how to place a horizontal mattress suture. But her brain ordered her hands automatically to try to traverse the wound, which is correct for the horizontal mattress pattern – except when using the inverting horizontal mattress technique. For this technique, rotate the suture placement by 90°, and drive the needle parallel, rather than perpendicular, to the wound margins.

I love this technique, in that its familiarity makes it deceptively difficult to perform in real time without deliberate practice. Grab a suture pad, and try it for yourself… before you are in a situation where you have to try it for the first time on a patient!