Clinical Exercise: Simple Interrupted Suturing

Scenario:

You are performing an axillary artery exposure surgery on a 45 year old patient  accessing the artery by an incision through the upper thoracic wall. This incision passes through the skin and subcutaneous tissues as well as separating pectoralis muscle fibers so they can be pulled to the sides. Post-surgery, you intend to stabilize the area with several sutures. 

Diagnosis/Considerations:

You recognize that careful suture placement, spacing, and neat alignment of the cut surfaces will significantly improve healing. Additionally overall 'neatness' is a hallmark of expertise. Since the separated muscle edge is no longer smoothly continuous you decide upon a simple interrupted suture technique to place several sutures to the muscle, subcutaneous tissue, and skin.

You considered the use of cyanoacrylate surgical adhesive (which is not the same chemical version as the household super-glue), however you concluded that tension in the muscle would be too high and surgical adhesive unlikely to be sufficient. 

You also considered use of internal metal staples, but decided that the higher accuracy of placement precision possible with sutures would provide a superior outcome. Additionally, you realize leaving metal staples behind in the musculature of an area as mobile as the pectoral region could result in some long term irritation during movement.

Mechanism:

The goal is to bring the edges of two tissues (a cut) close together to promote healing, but not to pull them so tight as to cause indenting or blanching (whitening) that would indicate blood flow in the edges of skin has been impeded by the sutures themselves. The oldest recorded description of the uses of sutures date to Egypt around 3000BC, with a 1000BC mummy having been found with physical sutures present in the skin. The 'father of modern medicine', Hippocrates, described the details of inserting sutures using techniques that have changed little since his time.

As a rule sutures are a short term device to assist with healing following trauma or wound. They can be designed to remain permanently within a patient (often biodegradable) or in the case of skin closing be designed for removal at a later date. The amount of time that skin sutures remain in place varies with the extent and type of injury, but generally facial sutures get removed after 3-5 days, scalp after 7-10 days, limbs following 10-14 days, and body trunk after 7-10 days.

The simple interrupted suture technique is the most commonly used approach and involves each stich being individually placed and tied. This is known as 'interrupted' since individual suture stitches are not connected. Simple interrupted suturing is useful for edges that may require differently angled sutures for best support and will enable continued support even if one suture fails. There are many additional suture styles used for specific applications (you will learn about many of these later in your training).

Treatment (perform these steps on the donor in a mock-procedure):

PREPARATION: Send a member of your team to the instrument supply tables to fetch five suture packets (one per student, extras are available as needed, but please initially take only the supply numbers indicated to ensure sufficient supplies are available for all tables).

Suturing is a foundation surgical skill, so take a little time to practice performing the simple interrupted stitch. Note, that the type of suture needle used today is incapable of penetrating skin, so practice your suturing on muscle or subcutaneous fascia.  The posterior side of the breast or the pectoralis muscle are ideal targets to suture.

1) Open a suture packet, observe the tip of the needle is embedded in protective foam or a protective plastic clip.

CAUTION: exercise care when handling suture needles to prevent impaling yourself. While some surgeons will handle needles with gloved hands, by far the safest technique to prevent needle-stick injury is to use forceps/hemostats to handle the sutures.

2) Grasp the base of the needle where the thread is attached firmly with a pair of hemostats (short tip hemostats are referred to as needle drivers) holding it in one hand.

3) With the other hand use a pair of forceps, such that one arm of the forceps is on each side of the cut, and press the cut edges of the transected muscle or subcutaneous tissue into close proximity with the correct opposing edge.

You may find the forceps with teeth allow a more secure grip on the tissue allowing you to hold cut edges easily together. If the edges are difficult to keep in position, one of your team members could hold the forceps while you work.

4) Insert the point of the needle into the muscle on one side approximately 3-5mm from the edge.

5) With a 'scooping' motion insert the needle through the muscle such that the point emerges from the tissue on the other side of the cut approximately 3-5mm from the cut edge.

6) Release the base of the needle and with the hemostats grasp near the tip to draw the body of the needle all the way through.

7) Continue drawing the suture thread through the opening until approximately 3-5cm of thread is left on the starting side.

8) Cut the thread on the needle side such that you have approximately 5-8cm of thread emerging from the second side of the suture.

For safety, keep hold of the needle and place the needle into a secure container (e.g. emesis basin) for safekeeping. 

9) With a forces or a hemostat grasp the long end of the thread.

10) Wrap this end of the thread twice around the end of a second pair of forceps.

11) Slightly open that second pair of forceps and grasp the free end of the thread (which is the other end from that grasped in the first forceps/hemostat).

12) Pull this free end of the thread through the loop that was made around the forceps, pulling till the thread forms a snug knot.

This is a basic overhand knot commonly referred to as a 'throw' in surgical specialties.

13) Move the second pair of forceps back to the midline of the cut and make an additional knot (throw) around the forceps using a single thread wrap, pulled tight in the opposite direction from the first throw.

This double wrap throw followed by a single wrap throw is often called the 'surgeon's knot' providing good strength. Additional throws (2-3) can be added as required to strengthen the knot.

14) Place another suture 5-7mm from the first to make a series of interrupted sutures along the incision.

Each member of your team should have has the opportunity to place a few sutures using one suture pack each, there should be enough thread on each needle for ~3 individual sutures to be placed.

NOTE: when finished suturing ensure that all suture needles are collected into one of your trays and transported to the sharps containers for safe disposal. Make sure to account for each of the suture needles you used...leaving an instrument behind inside a patient after surgery is a mistake we strive to avoid!

Now that you know how to place a suture, remember during your dissection if you inadvertently transect a vessel or nerve you can always suture the ends back together.

Outcome:

The sutures are neatly performed and the patient recovers well. You anticipate full healing with minimal long term concerns.