A.
B.
C.
Clinical Applications
1.
Adjustment and Removal of Interrupted and Continuous Sutures in
2.
Penetrating Keratoplasty
Lid Laceration Repair
3.
4.
Post chalazion incision and curettage (transcutaneous approach)
Suture Barb Removal after Cataract Surgery
5.
6.
Releasable Sutures in Glaucoma Filtering Surgery
Adjustable Sutures in Strabismus Surgery
Sterile Technique
Instrumentation for Suturing
1.
Forceps a) Tying
2.
b)
(1)
(2)
Tissue
Smooth platform to grasp needle without damage
Provide secure contact when grasping suture material
(1)
Needle Holders
Aid in handling of unstable wound edges
3.
Variations in Needle Holders
Smooth
Curved
Locking
Non-ratcheted
Grooved
Straight
Non-locking
Ratcheted a) Clinical Pearls:
(1) Smooth platform can grasp needle at right angle or slightly
(2) obliquely
Risk for damage to needle if platform is grooved
(3)
(4)
Damage to needle more significant in continuous suture procedures
Should not be used to grasp suture materials due to high forces that can damage delicate suture material
(5)
(6)
Excessive pressure by the needle holder may damage the needle and increase the risk of needle bending or breakage
Remember to apply the force to the needle along the direction of the curve of the needle
Needles a) Degree of Curvature
(1) describes the shape of the needle and may vary from straight to 5/8 (of a circle)
¼ Circle 3/8 Circle ½
Circle
5/8 Circle Straight b) Cutting Profile
(1)
(2)
The needle itself may have different profiles to the tip and the shaft
Reverse cutting needles have a triangular profile

(3) Spatula needles allow the surgeon to view and control the depth of penetration of the needle c) d)
Reverse Cutting Spatula
Clinical Pearls
(1) Diameter of the needle is generally measured in millimeters
(2)
(mm)
Needles may be sold separately from suture material or
“swaged on” meaning that the suture material is bonded to
(3) the needle
Swaging reduces the thickness profile of the suture material to a single strand from a double strand that is looped through the needle opening.
Needle Position
(1) Needle needs to engage the tissue vertically rather than
(2) obliquely
Suture will rest within opening but if opening is oblique, then tissue can tear and the suture can loosen
4.
Sutures a) Suture Characteristics
(1) Sutures vary in size from 10 to 1 and then 1-0 to 12-0 with
10 being the largest and 12-0 being the smallest
(2) Characteristics include absorbable vs. non-absorbable, coated vs. uncoated, dyed vs. undyed, monofilament, spun or braided, length of suture
Absorbable Suture Materials
Natural
Plain gut
Chromic cat gut
Synthetic
Polyglactin (Vicryl)

Braided synthetic

Handles like cat gut, knots securely because of braiding
Polyglycolic acid (Dexon)

Degrades slower, more predictably than cat gut
Non-absorbable Suture Materials
Natural
Silk

Silicone coated, braided

Supple, strong, handles well

Avoid in contaminated wounds due to risk for abscesses particularly in skin wounds
Linen
Synthetic
Polyamide (Nylon)

Difficult to tie monofilament, braided preferred
Polypropylene (Prolene)

Glides easily through tissue, similar to monofilament nylon

Polyester (Dacron)

Cotton Steel

Hard to manage, kinks easily
D.
E.
F.
Suture Techniques
1.
Simple or Interrupted
2.
a) b)
Mattress
Presses wound margins together
For small wounds e.g. short corneal incision a) b)
Incisions through deep tissue e.g. lid procedures that involve skin muscle become depressed as they heal due to vertical contracture of scar tissue
Mattress sutures help to evert the skin edges and close the wound
3.
4.
c) Slightly loose closure for these sutures helps to prevent a thickened hard scar than can occur with a tight suture
Running or Continuous a) b)
For longer incisions or lacerations
Suture will not approximate skin edges as finely as interrupted suture c) The entire suture will lose its strength if it breaks at any point along its length d) Used in adjustable sutures for penetrating keratoplasty
The “Halving” Principle a) b)
To prevent wound gape
Initial suture is placed in middle of incision with remaining sutures alternated to either side
Suture Tying
1.
Surgeon’s Knot
2.
a) b) c) d)
The short end of the suture should be released
The long end of suture material is wrapped around the forceps three times (multiple throws).
The knot should be created by moving the suture material off of the forceps and drawing the hands away from each other (crossed).
This knot is tightened securely but should not be over-tightened. The suture material should lie flat rather than be coiled into a ball. This surgeon’s knot should be followed by locking knots (see below)
Locking Knot a) The short end of the suture should be released
3.
b) The long end of suture material is wrapped around the forceps one time in the opposite direction to that used in the surgeon’s knot
(single throw)
Two or three additional knots should be tightened, each with a c) reversal in the direction of the throw
Burying the Knot a) The knot should be pulled deeply into the canal then the knot should then be reversed until it lies just under the surface to redirect the
Suture Removal suture ends pointing away from the surface to prevent later removal
1.
Method a) Grasp the knot with forceps and lift gently away from the wound. b)
Using sharp, fine scissors, cut the suture just at the skin surface.
Pull the suture across the incision to remove it rather than away from the incision to prevent re-opening the wound