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Suturing 101: Needles, Sizes and Materials

Don’t you hate when as a new nurse practitioner or NP student a patient asks “Have you done this before?”.  Sometimes, of course the answer is “No (never, not ever and I am so nervous I might pee my pants)”.  But, you can’t actually say “No, I have never done this before,”so you beat around the bush and try to redirect the conversation.  To make the never-done-this-before situations less anxiety provoking for you and especially your patients, it is necessary to do a little learning and makeshift practice before performing a new procedure.

Suturing is one of my favorite procedures.  It’s a bit messy but gratifying to see the results of your work come together restoring a person’s appearance.  There are a few foundational things you need to know before repairing lacerations in the real world.   In this suturing 101 series, let’s stick with the basics.  Over the course of a few posts I will run through repairing a simple laceration with a basic simple suture.

As with any project or procedure, the first step to beginning any laceration repair is selecting the proper materials.  In the suturing world, selecting your needle type and size and “thread” material and size are the starting point for every laceration repair.

Types of Suturing Needles

Nope, not all needles are created equally when it comes to sewing up a laceration.  Providers use 2 main types of needles for suturing, cutting needles and tapered needles.

  1. Cutting Needle- This needle is designed with a sharp tip and edges making it ideal for penetrating the skin and therefore placing skin sutures.  You will likely use a cutting needle for most of your procedures.  One specialized type of cutting needle, the reverse-cutting needle, is stronger than the conventional cutting needle and is designed for penetrating tough tissues.
  2. Tapered Needle- Tapered needles have a sharp tip and smooth edges in contrast to the sharp edges of cutting needles.  These needles are ideally suited for subcutaneous tissues as they are difficult to pass through the skin.

Needle Sizes

I know we’re going for Suturing 101 type material here so don’t be intimidated by needle sizing terminology.  Once you get the idea, it’s simple stuff.  The cord length of the needle (also known as bite width) is the distance from the swage (where the “thread” connects to the needle) to the needle tip.  Needle length is simply the distance from swadge to needle tip.  Use the needle with the smallest possible length for your procedure, you will get better results.

Suture Sizes

Suture sizing is just like the sizing for IV’s and injection needles- the smaller the suture, the larger the number.  The smallest sutures, 10-0, you will likely never use as a nurse practitioner.  These tiny sutures, as fine as human hair, are used for microvascular procedures.  The largest sutures, 00, are as large as fishing line and are used for procedures like closing the abdominal wall, also something you probably won’t encounter as a NP.  Most commonly, you will use a suture somewhere between 3-0 and 6-0.  Small sutures, such as 5-0 and 6-0 are used on the face.  Larger sutures, 3-0 and 4-0, are best for areas where appearance is not of great concern such as the extremities.

Suture Material 

There are many types of suture material and fortunately they can be easily divided into four categories making them simple to remember.

  1. Nonabsorbable Sutures- Nonabsorbable sutures are not dissolved by the body and therefore must be removed.  They are less scarring than absorbable sutures if removed in a timely manner and are primarily suited for use on the skin.  Nylon (Ethilon) and Polyprorylene (Prolene) are the primary types of nonabsorbable sutures.
  2. Absorbable Sutures- Absorbable tissues are dissolved by the body’s tissues and therefore do not need to be removed.  They are best suited for use under the skin as they produce a pronounced scar if used externally.  They can also be used if there is concern a patient may not return for suture removal.  If you suspect this is possible, you must warn the patient of the probability of increased scarring.   Common types of absorbable sutures include Polyglecaprone (Monocryl), Polyglactin-910 (Vicryl), Polyglycolic acid (Dexon), Gut and Chronic Gut.
  3. Braided Sutures- Braided sutures are comprised of several small strands twisted together.  They can be easier to tie than nonbraided sutures however the tiny gaps between suture strands can harbor bacteria increasing risk of infection.
  4. Nonbraided Sutures- Nonbraided sutures, also known as monofilament, are made of single strand.  These types of sutures are typically used in skin closure and in wounds where there is risk of infection.

Alright, I think that’s enough for one day!  If you want a more in depth review of suturing needles, sizes and materials check out this online Pocket Guide to Suture Materials, Techniques and Knots released by suture manufacturer Serag Wiessner.  Tune in later this week for more suturing 101.  Oh, and bring a banana to the next lesson. Yes, your heard me correctly, a banana.