Suturing 101: A Stitch In Time…

Time to Suture

Great! You’ve attended our course and got your first taste of suturing. You went home and practiced your suturing techniques and are feeling pretty good about your newly developed skills. Now, you’ve arrived back at the office and as you begin your shift the attending says, “Glad to see you! We are getting slammed this morning. The best way to help out is to suture these patients while I go see more patients. I have their charts all done but as soon as you get them sutured, let me know and I can have them discharged.” You walk down the hall and introduce yourself to the patients and let them know that you are the only thing standing between them, a beautiful skin repair, and discharge from an already lengthy stay.

The moment of truth has arrived…you enter the supply room to pick your sutures and suddenly you are dizzy with the possibility of needle sizes and suture sizes.

• 4-0, 5-0 or 3-0?
• Absorbable or non-absorbable?
• Prolene, Vicryl, Silk, Staples?
• What type of closure should I do?
• Is this simple or complex?
• Vertical or horizontal mattress?

What does all that mean and what does it mean to me? Use the material here to create yourself a suturing tips cheat sheet (3×5 card or note on your smart phone) to help you the next time you venture to peak into the suture cart.

The truth is that you could literally write a book on this topic and many people before me have already done that. My favorite is Wounds and Lacerations: Emergency Care and Closure by Alexander Trott. Not only did I find this book a great help as a student and new practitioner, but I also have given it to many students and residents that I have worked with and taught. If you have attended our course, you have probably had me show you pictures from the text to help the suturing techniques make a little more sense.

INITIAL HISTORY

The initial history will play a key role in your care of a laceration in the ED.
How did this happen? This will give you a clue to the possibility of further trauma (possible open fracture, possible retained foreign body). After some experience, you will notice specific wound patterns correlating to specific injuries. An example would be a stellate wound from “starring” the windshield or the “hockey stick” pattern from hitting the corner edge of an object.

Timing? How long ago did this happen. In general, we do not do a primary closure on a laceration older than 12-24 hours.

Medications? Is the patient on “blood thinners”, anticoagulants, NOAC, DOAC, etc…whatever term you prefer to use.

Tetanus status? Are they current and up to date?
Examination: neuro-vascular intact, tendon function intact, foreign bodies, wound shape and edges. Do a good physical exam.

WOUND CARE/PREP

“Dilution is the solution to pollution”
Cleaning and irrigation are the basis of favorable outcome of a wound closure and the most important way to decrease wound infection. The most common cleaning agents that you will probably find around your practice setting are iodine surgical scrub, povidone-iodine solution, Chlorhexidine, hydrogen peroxide or good ol’ soap and water.

My personal favorite is soap and water from the sink in the patient’s room. Depending on the location or severity, not all wounds are amenable to this solution. Sterile saline can also be used to irrigate uncomplicated wounds. But, tap water is an acceptable (and cheaper and more time efficient solution). “A meta-analysis of three studies in adults and two studies in children compared irrigation with normal saline or tap water for preparation of acute lacerations. No clinically significant difference in wound infection rates were seen.” For style points, I usually anesthetize the wound prior to cleaning because the cleaning process is a pretty painful otherwise.

Another acceptable cleaning method is a dilute mixture of povidone-solution (Betadine). I will often times use a 1:10 mixture of Betadine and saline solution in a highly contaminated or large wound. Iodine surgical scrub should never be used because this detergent is toxic to wound tissues and could actually impair wound healing. Although to a lesser degree, chlorhexadine and hydrogen peroxide are also toxic to wound tissues and are not recommended for use.

Pressure and Volume: Current literature recommends a wound irrigation pressure of 5-8 psi. This can be accomplished by connecting a syringe (35ml or 60ml) to a 19g catheter. This will give you 7-8 psi needed to reduce the bacterial contamination and debris from most lacerations. As for an adequate volume, it depends. A small 1cm laceration may require only 150ml but a large dirty laceration may require 500ml or more.

TETANUS

Current ACIP and CDC recommendations for Tetanus immunizations can be found on their websites. ACIP has recommended a tetanus-toxoid containing vaccine and tetanus immune globulin (TIG) as standard wound management to prevent tetanus. Tdap is preferred for patients who have not previously had Tdap or has an unknown status. ACIP and CDC have summed up the recommendations with a chart that basically reads like this: #1 no previous immunization status or status is unknown: clean and dirty wounds get a tetanus update. #2 If currently up to date, the recommendation is based on a clean wound or contaminated wound. No update is needed on a clean and minor wound if the last update was within 10 years. If it is a contaminated wound, the most current immunization has to be within 5 years.

SUTURE SELECTION

The first decision in suture selection is between absorbable or non-absorbable. Most of what you will probably be using is non-absorbable but there may be times when you to use absorbable. Personally, I use absorbable sutures in the mouth, on the lips, or when performing a complex closure with internal sutures to help reduce tension of the external wound edges. The most common selections are gut/chromic gut, Vicryl, and PDS. Each has a trade off with tensile strength, half-life to dissolve, and tissue reactivity but I generally opt for Vicryl as my absorbable “go-to” suture.

The non-absorbable selection offers a little more variety and ultimately is the user’s choice for preference. The most common names are silk, nylon/Ethilon, or Prolene. Again, the common trade-offs are tissue reaction, tensile strength, and knot security. Silk is easy to use and handle, the knots are very secure but it has high potential to react with the skin tissue. Nylon/Ethilon has very good tensile strength and low tissue reactivity; however, it may require a few extra throws to lock the knot as the memory of the thread will help to untie the knot. Lastly, Prolene has the highest tensile strength and lowest tissue reactivity but it has the highest degree of memory (the tendency of a suture to hold its shape which helps the suture untie itself) so it requires 1-2 throws more per knot than silk. My favorite trait of Prolene is the dyed coloring. Prolene is typically blue although can be ordered in a variety of colors including clear). This blue color makes it very easy to see and makes removal a bit easier.

NEEDLE TYPE

When you look at the suture packaging, you will see the needle described in 2 ways: reverse cutting or taper and a code such as PS-2, P-3, FS-2, etc.
The easiest way to describe the difference between reverse cutting and taper is to look at the end of the needle (called the point) and then visualize the cross-section. A taper needle comes to a point and is circular/conical in nature. The taper needle is smooth compared to cutting needles. These are used for tissue that is easy to penetrate such as bowel or blood vessels. You should never use taper needles to suture skin because the excessive force needed to get a taper needle through the skin causes excess trauma to the skin.

A cutting needle has a triangular cross-section and as the name implies is used to cut through and penetrate tough tissue such as skin. The apex of the triangle forms the cutting surface of the needle. After you have chosen a cutting needle, you choose your size of cutting needle. The most common cutting needle types for suturing are:

• FSLX (for skin/ extra large): used for large skin closure with a lot of tension
• FSL (for skin large): used in procedures with high tension closures
• FS2: Used for common closing of skin
• P3: Used for closing small incisions.

In the Urgent Care and ED setting, mostly you will be using a cutting needle with FS2 or P3.

SUTURE SIZE

In discussing suture size, the smaller the number the larger the thread. A 1-0 is larger than a 6-0 suture. The optimal choice of suture size is to use the smallest size that will close the wound appropriately. The larger the suture, there is increased additional trauma to the site and increased likelihood of scarring. Here are my recommendations:

• Face: 5-0 to 6-0
• Small wounds on extremities: 4-0 or 5-0
• Larger wounds on trunk or extremities: 3-0 or 4-0

SUTURE TECHNIQUES

Rather than review the course material of how to tie the various techniques, let’s focus on when to use the various suturing tips & techniques you learned. As you suture, you have 2 goals: match the skin layers and evert the wound edges. Failure to approximate like skin layer to like will cause improper healing and a large scar. Due to the skin’s normal contractility, a wound with everted edges as it heals will contract into a nice smooth surface. Wounds that are strangulated/inverted contract into depressed scars that develop into linear pits that will cause shadows and highlight the poor cosmetic outcome. Two sayings that I learned during training help keep these goals in mind: “Approximate don’t strangulate” and “Build mountains not dig ditches”.

Simple Interrupted

This is your bread and butter technique and is the base technique/knot for all other suturing techniques. If a single suture should happen to break, the rest of your sutures will hold the laceration closed. This technique is very versatile, quick, and easy.

Vertical Mattress

Useful for wound edge eversion. It allows for precise approximation but with little tension. This is useful in areas of skin laxity such as the elbow where wound edges fall or fold into the tissue. This technique is also used to reduce tension on gaping wounds. The width of the stitch should increase based on the amount of tension. That is, the greater the tension, the wider the stitch.

Horizontal Mattress

Another technique useful for wound edge eversion. It is more frequently used in fascia than in skin. It is commonly used in calloused areas like the palms or soles of the feet. I choose this technique when there is a larger laceration with moderate or significant gapping as this technique shares the tension along the entire wound edges and also everts the wound edges. Another technique for using the horizontal mattress is to use this technique as a first suture/anchor suture/holding suture in a high-tension wound. Once the initial edges are anchored and approximated creating lower-tension of the wound edges, then you could then suture with the simple interrupted technique.

Deep Closure/Complex Closure

This type of closure requires 2 techniques and both absorbable and non-absorbable sutures. This technique is chosen when there is significant gapping of wound edges or dead space deep in the laceration. In this technique, your absorbable suture would be used to bury the knot at the lowest point of the wound. This pulls together the wound edges and reduces overall tension and gapping. After the internal sutures are placed using the deep closure, switch to the non-absorbable sutures and close the outer wound edges using whichever technique you prefer.

Running Suture

This is used when time and length are a factor. Generally, I may run a suture if it is over 5cm. However, the caveat to this is patient care of the suture/wound. Any break of the suture will cause the whole suture line to fail and/or pull out entirely and possibly cause wound dehiscence.

Skin Adhesive and Staples

A quick word about skin adhesive. They can be a real time saver, particularly with children. A study was performed on laparoscopic surgical sites that showed no cosmetic difference at 3 months follow-up from those sites closed with sutures versus those closed with skin adhesive. This is less traumatic, particularly in the pediatric population. Although, the initial cost for material/unit is higher with skin adhesive, the return is more cost effective since it would not necessitate an office visit for suture removal. In some wounds, I will combine steri-strips with skin adhesive.
Although I have used staples as primary skin closure on large lacerations of the extremities (such as in a trauma setting when there are higher priorities), I would save staples for scalp lacerations that are not conducive to other suture materials.

TIME TO SUTURE REMOVAL

In my practice, your discharge note will have one of two options for follow-up times. You will follow-up in 5-7 days or 7-10 days.

• Face: 5-7 days
• Scalp: 5-7 days
• Trunk: 7-10 days
• Extremities: 7-10 days

SUMMARY

I have sutured in settings from plastic surgery to trauma and in the ER to the OR. Your practice environment will dictate the materials and techniques that you choose or have available to you. For the ED and Urgent Care setting, I will recommend the following:

Sutures:

Reverse cutting needle of P3 and FS-2, a mixture of absorbable and non-absorbable. I prefer Ethilon, Prolene, and Vicryl or Monocryl. You will need a good mix of sutures sized 3-0 to 5-0. Suture size will be driven by wound size and location (see discussions above).
Techniques: Master the simple interrupted. Other techniques are available based on the wound shape. Also be familiar with your skin adhesive and staples.

The goal is return the skin to normal function, without infection, and an excellent cosmetic outcome.

This is just the very tip of the iceberg. Again, many books have been dedicated to these topics. As with this particular topic, further blogs will be driven by your questions and comments. What you would like answered or need to know? Let us know what you would like us to talk about. Advanced repair techniques, regional anesthesia and nerve blocks, bite wounds, open fractures…the possibilities are limitless.

1 Brancato, John C. “Minor wound preparation and irrigation.” Uptodate.com. https://www.uptodate.com/contents/minor-wound-preparation-and-irrigation?topicRef=15912&source=see_link#H18 , Accessed 18 Feb 2019.

2 “DTap/Tdap/Td ACIP Vaccine Recommendations”, https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/dtap.html.

3 https://www.theapprenticedoctor.com/comparison-different-suturing-needles-available-today/ . Accessed 18 Feb 2019

4 Buchweitz, Olaf et al. Cosmetic outcome of skin adhesives versus transcutaneous sutures in laparoscopic port-site wounds: a prospective randomized controlled trial. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4887523/