Sutures 10 Sutures in practice

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Sutures 10 Sutures in practice

This subsection has text from an interactive multimedia training program on basic 
surgical skills called PrimeSkills in Surgery.
You can use this subsection on its own or follow the whole program (further details at the end of 
this subsection).


Length

Strength

Friction

How to avoid breakages


Length


Keep tidy.


Use straightened sutures.


Lay unused sutures out of the operating area.


Don't economise with hand tied sutures.


Hand tied sutures need at least 8cm. of free end of suture for a successful throw.


Do economise with instrument tied sutures.


Instrument ties need only 2cm. of free end of suture to avoid tangling.


Strength


The suture needs to be strong enough to withstand:


Pulling the tissues together with the first throw of the knot.


The rest of the throws of the knot.


The stresses of the tissues during the healing phase.


A suture with a strength of 2000gm. will be more than adequate for safe stitching of skin without breaking.


If you find that the stitch is breaking, the tissues are being seriously overloaded and damaged.


To pull together two edges of skin, or subcutaneous fat, lying loosely side by side, requires only about 100gm. of strength in the

first throw of the stitch.


If there has been tissue loss following excision of an ellipse of skin, the first throw needs to be pulled harder to drag the skin


edges together.


A pull of 500gm. on the first throw will probably not damage the tissues.


A pull of 1000gm. on the first throw will cause pressure necrosis, partial or full thickness.


This will lead to local healing of the epidermis by fibrosis (scarring) rather than by regeneration.


With a pull of over 2000gm., the suture will probably cut through the tissue.


The pulls on the second, and any third throw are as high as 800-1000gm., being essentially locks on the first throw.


Some skin is always under tension such as over the shoulders, on the shins, or the tip of the nose.


Other skin is intermittently stretched such as over the knee joint, knuckles and elbows.


All absorbable and non absorbable sutures down to 5/0 (metric 1) will withstand these stresses while healing occurs.


Non absorbable skin stitches can all be removed within 14 days. ( Within 3 days in unstressed thin skin such as on the face).


Friction


The friction of braided sutures is relied on to prevent knots and subcuticular sutures slipping.


Pulling braided sutures can damage delicate tissues such as bowel or thin skin.


The slippery monofilament sutures are chosen to:


Allow snugging of a knot with the second throw.


Insert and remove nonabsorbable subcuticular stitches.


Allow easy removal of a sutures.


How to avoid breakages


Hold the suture and not the needle when pulling.


Avoid gripping the suture with harsh instruments.


Let the needle hang and rotate freely to unwind a twisted suture. A twisted suture can kink and snap.


If you jerk the suture, you may be able to break it, because you can produce a strain of more than

2500gm. momentarily without too much pain.


Jerking the suture is what may happen if you are stressed.


Under these circumstances your pain threshold is likely to rise and your technique is likely to deteriorate.


Relax a little.


Next subsection, click on Sutures 11 Checking sutures
Last subsection, click on  Sutures 09 Exercises
Surgical Education and Training page, click on Surgical Education and Training
Whole program on WikiSurgery, click on PrimeSkills in Surgery
Whole program on CD-ROM, click on Michael Edwards