09.06-07 Suturing Techniques
Inserting each suture correctly is the key to good wound closure. Here you will learn how to place a suture and how to avoid damage to the wound edges.
You should be familiar with how to use the needle holder and suture needle to insert a suture with minimal tissue damage.
This module covers simple interrupted, continuous, subcuticular, mattress and pulley sutures and has plenty of tips on how to overcome common problems.
In this module
09.06 Mattress & Pulley Sutures
Mattress sutures represent an alternative form of interrupted suturing. They may be either vertical or horizontal. Typically they are used for closing larger surgical wounds and traumatic lacerations. They can be useful for ensuring either eversion or inversion of a wound edge and for situations where more tension is needed to approximate irregular skin edges.
This type of suture can lead to an unsightly scar and is not often needed.
09.06.01 Vertical Mattress Sutures
A vertical mattress suture starts some distance from the wound edge, passes deeply under the wound and emerges on the opposite side at the same distance from the edge. It then returns by taking a more superficial bite (just a few mm) from each wound edge. The suture draws the edges together and the knot is tied on one side.
Compared with a simple interrupted suture, this suture pattern allows better closure of dead space and better apposition of wound edges. However, the disadvantage is that there is more risk of injury to wound edges, so it should be used with caution.
09.06.01.01 Principles
A vertical mattress stitch consists of “far-far” and “near-near” components. It starts with the “far-far” component which is exactly like a simple interrupted suture. A bite is taken approximately 4mm from the wound edge, passing deeply under the wound and emerging on the opposite side at the same distance from the edge.
For the “near-near” component, the needle is reversed in the needle holder and returns by taking a more superficial bite (just a few mm) from each wound edge. The curved path of the needle is followed at all times.
The suture is pulled through, taking great care to follow the line of curvature and the edges are drawn together. The knot is tied on the side of the wound where the needle emerges.
This pattern is repeated until the wound is closed, with intervals of approximately 4mm between stitches. The resulting suture pattern shows stitches that do not appear to cross the wound and knots tied all on one side.
09.06.01.02 Practise
Insert the suture approximately 4-5mm from the wound edge, passing deeply under the wound and emerging on the opposite side at the same distance from the edge.
Reverse the needle in the needle holder and pull the suture through. Now go back, this time taking a more superficial bite of just a few millimetres. Be sure to keep following the line of curvature of the needle when pulling the suture through to avoid tearing.
Tie the suture on this side of the wound. Use a surgeon's knot for extra security, or a standard reef knot. Cut the suture ends leaving a length of approximately 0.5cm.
09.06.01.03 Things To Avoid
If the return superficial bite is not handled with extreme care, there is a danger that it may pull through and tear the skin edge. The best way to avoid this is to make certain not only that your bite follows the circular path of the needle but that as you pull the suture thread through you continue to follow the line of the curvature.
09.06.02 Pulley Sutures
A pulley suture is a modified vertical mattress suture and can be useful where there is unexpected tension on the wound edges. One end of the suture is passed through the loop at the apex of the suture. This provides a mechanical advantage in apposing the edges and distributes tension more evenly.
09.06.02.01 Practise
Start your pulley suture like a vertical mattress suture, passing deeply under the wound and emerging on the opposite side of the wound at the same distance from the edge.
Reverse the needle in the needle holder and go back, this time taking a more superficial bite of just a few millimetres.
Now pass the needle back through the external loop of suture on the other side of the incision and pull it across. Tie using standard reef knot technique.
Your new loop functions as a pulley, directing tension away from other strands.
09.06.03 Horizontal Mattress Suture
A horizontal mattress suture passes deeply under the wound like a simple interrupted suture, but a horizontal bite is then taken before returning to the other side.
The finished suture should be approximately square.
09.06.03.01 Principles
With a horizontal mattress suture, the first suture should be inserted approximately 5mm from the wound edge, pass deeply under the wound and emerge on the opposite side of the wound at the same distance from the edge. The needle is reversed in the needle holder but this time, before going back to the other side of the incision, it is moved horizontally approximately 5mm. A reef knot or surgeon's knot is then tied in the same way as for an interrupted suture and the suture material cut.
The finished suture should be approximately square.
09.06.03.02 Practise
Begin as if you were inserting a standard interrupted suture. Take a bite on the first side of the wound ensuring that the needle follows the line of its curvature. Remove the needle and reposition in your needle holder before taking a corresponding bite on the other side of the wound. Hold the needle with the forceps and rotate it in the needle holder to prepare for the backhand part of the mattress suture.
Now take a bite on the same side of the skin, staying parallel to the incision or wound. The bite should be the same size as the width of the suture you have just placed. Now take a return bite to the opposite side of the wound. Pull the suture through and then tie a standard knot without excess tension. The finished suture should be approximately square. Trim the ends. Continue with equally spaced horizontal mattress sutures until the wound is closed.
09.06.04 Continuous Mattress Sutures
This type of suture is useful when dealing with a large skin incision that needs to be closed quickly. It tends to stop bleeding from the edges more successfully than an interrupted suture and there is no time taken up in cutting of individual knots.
One side of the wound follows the horizontal mattress methodology, whilst the other follows the vertical mattress methodology. The finished result is asymmetrical, with vertical bites on one side of the wound and horizontal bites on the other.
09.06.04.01 Principles
This closure begins in the same way as an interrupted vertical mattress suture, with a deep bite under the wound followed by a more superficial return bite. A standard reef knot or surgeon's knot is tied. However, the long suture strand is not cut.
The needle is then reversed in the needle holder and a horizontal bite is taken on the same side before taking a deeper bite under the wound back to the other side. The needle is reversed in the needle holder again and returns to the other side of the wound with a superficial bite, emerging just beyond the point at which the horizontal bite finished.
The closure continues in a similar fashion - horizontal bite, deep bite to the other side, superficial return bite. Ideally, an assistant should follow you during this procedure, ensuring that the long suture is kept out of the way whilst you are working, but our video shows you how to practise this technique alone.
09.06.04.02 Practise
Insert the first suture approximately 5mm from the wound edge, passing deeply under the wound and emerging on the opposite side of the wound at the same distance from the edge. Reverse the needle in the needle holder and pull the suture through. Now go back, this time taking a more superficial bite of just a few millimetres. Tie the suture on this side of the wound. Use a surgeon's knot for extra security, or a standard reef knot. Cut the short free suture end leaving a length of approximately 0.5cm, but leave the long suture strand uncut.
Reposition the needle in the needle holder and take a horizontal bite of approximately 5mm on the same side of the wound, before returning to the other side of the wound with a deep bite. Reverse the needle in the needle holder and go back to the other side of the wound with a more superficial bite, emerging just beyond the point at which your horizontal stitch finished. Reverse your needle in the needle holder and take another horizontal bite before going deep under the wound to the other side. Continue the closure in this same pattern – superficial, horizontal, deep, superficial, horizontal, deep.
To complete the closure, leave a loop of suture when you pull through the last suture bite, and tie off using an Aberdeen knot. Cut the suture strands, leaving a length of approximately 0.5cm.
09.07 Undermining
Excessive tension can lead to ischaemia and poor healing. Judicious undermining with a scalpel may be needed in some cases to relieve tension on a wound edge.
Lift the skin edge with a skin hook or forceps, and with your scalpel cut into the deep subcutaneous tissue along the length of the wound until the skin has the required mobility. Try to stay at the same depth as you cut.
Be careful not to devitalise the wound edges by undermining excessively. A few small scalpel cuts is usually all that is needed.
09.07.01 Things To Avoid
If the skin is already diseased, devascularized or compromised in any way, undermining the subcutaneous skin tissue could lead to further devascularization or the sutures tearing through. In this instance you should undermine the fat deep to the skin instead. This will preserve any bloody supply and avoid necrosis.
09.07.02 Practise
Lift the skin edge with your forceps, and with your scalpel, make a series of cuts into the subcutaneous tissue along the length of the wound until the skin has the required mobility. Try to stay at the same depth as you cut.
Now, using the other side of the wound, practise mobilising the deeper fatty tissue. Make your incisions at a depth of approximately 1 cm, and cut back approximately 1cm under the wound.