science quiz bee questions.doc FOR ELEMENTARY SCIENCE
Surgical needles basics
1.
2. Outline
• Basic design
• Anatomy of a surgical needle
• Needle point types
• Needle performance characteristics
3. Surgical Needles
Surgical needles are necessary for the placement of
sutures in tissues; therefore, they must be designed
to carry suture material through tissues with minimal
4. Surgical Needles
They must be:
• Sharp enough to penetrate tissues with minimal
resistance.
• Rigid enough to resist bending, yet flexible enough to
bend before breaking.
• Sterile and corrosion-resistant to prevent introduction
of microorganisms or foreign bodies into the wound.
5.
6. Basic Needle Design
1. CHORD LENGTH—The straight line distance from the point of a curved needle to
the swage.
2. NEEDLE LENGTH—The distance measured along the needle itself from point to
end.
3. RADIUS—The distance from the center of the circle to the body of the needle if
the curvature of the needle were continued to make a full circle.
4. DIAMETER—The gauge or thickness of the needle wire.
7. Basic Needle Design
all surgical needles needles have three basic
components:
1. eye (or swage)
2. body
3. point.
point
Body
Eye
Swaged
needle
suture
8. Eye (Swage): Swaged needles are eyeless needles permanently
attached to the suture strand by the manufacturer.
THE NEEDLE EYE
The eye falls into 1 of 3 categories:
• closed eye: The closed eye is similar to a household sewing needle
• French (split or spring) eye: French eye needles have a slit from
inside the eye to the end of the needle with ridges that catch and
hold the suture in place
• swaged (eyeless):
10. Swaged needles
Swaged needles are sometimes known as atraumatic needles
because the thickness of needle and suture combined is much
less with an eyeless needle.
11. Body:
The body of the needle is the portion which is grasped by
the needle holder during the surgical procedure.
The body of the needle should be as close as possible to the
diameter of the suture material to minimize bleeding and
leakage.
Point
Sharpness and needle point geometry are critically important
characteristics
12. STRAIGHT NEEDLE
This shape may be preferred when suturing easily accessible tissue.
Most of these needles are designed to be used in places where
direct finger-held manipulation can easily be performed.
used for skin closure or in laparoscopy.
curved portion passes through tissue easily,
HALF-CURVED NEEDLE
13. CURVED NEEDLE
Curved needles allow predictable needle turnout from tissue,
This needle shape requires less space for maneuvering than a straight
needle
The curvature may be 1/4, 3/8, 1/2, or 5/8 circle.
1/2 3/8 1/4 5/8
14. COMPOUND CURVED NEEDLE
developed for anterior segment ophthalmic surgery.
It allows the surgeon to take precise, uniform bites of tissue.
Equalized pressure on both sides of the comeal-scleral junction
minimizes the possibility of astigmatism following anterior
segment surgery.
16. CURVED NEEDLE
Type Feature Applied Areas
1/2 easier to use in confined locations
may be obscured by tissue deep in the
pelvic cavity
Muscle, Eye, Skin
Peritoneum
¼ circle
Eye
Microsurgery
3/8 can be easily manipulated
Used relatively large and superficial wounds
Dura, Eye, Fascia
Nerve
5/8 circle Cardiovascular, Oral,
Pelvis, Urogenital tract
Straight Nasal cavity
Nerve, Skin, Tendon
Compoun
d curve
Eye (Anterior
segment)
18. Needle point Geometry
Taper-Point
•Suited to soft tissue
•Dilates rather than cuts
Reverse
cutting
•Very sharp
•Ideal for skin
•Cuts rather than dilates
Conventional
Cutting
•Very sharp
•Cuts rather than dilates
•Creates weakness allowing suture tear
out
Taper-cutting
•Ideal in tough or calcified tissues
•Mainly used in Cardiac & Vascular
procedures.
19. Atraumatic needles
- Simple thread (atraumatic)
- Manufactured connection of needle
and threads
- No Lace time
- No re-sterilisation
- No Care of needle-tip
- No Corrosion
20. PRINCIPLES OF CHOOSING A SURGICAL NEEDLE
• taper point needles are used to suture tissues that are
easy to penetrate.
• Cutting or TAPERCUT needles are used in tough, hard to-
penetrate tissues.
• When in doubt about whether to choose a taper point
or cutting needle, choose the taper point for everything
except skin sutures.
21. Needles Types
Taper Point Blunt Point Needles Conventional Cutting
Reverse Cutting Precision Point Reverse
Cutting Needles
Spatulated
22.
23. TYPES OF NEEDLES
CUTTING NEEDLES
two opposing cutting edges.
sharpened to cut through tough, difficult-to-penetrate tissue.
ideal for skin sutures
Because of the sharpness of the cutting edge, care must be taken
in some tissue (tendon sheath or oral mucous membrane) to avoid
cutting through more tissue than desired.
24. CONVENTIONAL CUTTING NEEDLES
conventional cutting needles have a third cutting edge on the
inside concave curvature of the needle.
The shape changes from a triangular cutting blade to that of a
flattened body on both straight and curved needles.
TYPES OF NEEDLES
25. TYPES OF NEEDLES
REVERSE CUTTING NEEDLES
specifically for tough, difficult-to penetrate tissue such as
skin, tendon sheath, or oral mucosa.
used in ophthalmic and cosmetic surgery where minimal
trauma, early regeneration of tissue, and little scar
formation are primary concerns.
26. TYPES OF NEEDLES
SIDE CUTTING NEEDLES
spatula needles,
designed for ophthalmic procedures. They permit the needle to
separate or split through the thin layers of scleral or comeal tissue
and travel within the plane between them.
The optimal width, shape, and precision sharpness of this needle
ensure maximum ease of penetration
27.
28. Types Shape Feature
Taper Point round-bodied needle
oval or flattened body
sharp point
easily penetrated tissue.
Blunt Point Needles round body
rounded blunt point
for suturing of friable tissue
(liver, kidney)
Visiblack Needles Round-bodied
slim tapering point
to facilitate penetration
Black surface
cardiac and vascular use
Conventional Cutting 2 opposing cutting edges with a
third cutting edge on the apex of
the triangular configuration
ideal needles for skin
Reverse Cutting 2 opposing cutting edges
edges are honed
cut through tissue that is
tough and difficult to
penetrate
29. Types Shape Feature
Precision Point
Reverse Cutting
Needles
sharp cutting edges
Squared needle body
for excellence in general skin closure
Spatulated side-cutting needles
flat on top and bottom
ophthalmic surgery
(side cutting edges enable the needle to separate
or split through the extremely thin layers of scleral
or corneal tissue)
TAPERCUT both the reverse
cutting edge and
Round-bodied nee
uniform cutting action,
readily penetrates dense tough tissue
for suturing dense, fibrous connective tissue
30.
31. Needle Point Types
Needle groups are illustrated in the chart –
SURGICAL NEEDLES
ROUND-BODIED
Round-Bodied
Blunt Point Needles
Visiblack
CUTTING
Conventional Cutting
Reverse Cutting
Precision Point Reverse
Cutting Needles
TAPERCUT
OPTHALMIC
Micropoint
Spatulated
32. Needle Performance Characteristics
The performance of a surgical needle depends on 2 major
features-
• Strength
• ability to penetrate tissues easily
• ductility
33.
34.
35. factors that affect a needle’s ability to penetrate:
1.Tip Geometry
2.Sharpness - Tapered needles can have slimmer, finer honed
(sharpened) blades.
3. Siliconization - A coating to minimize friction of the needle’s
passage through tissue can greatly facilitate penetration.
4.Wire Diameter
5. Body Shape
36. 3/8 Circle 5/8 Circle¼ Circle ½ Circle
Multiple curved
J-shaped
Straight
Progressive curved
Shape of needle
Notas del editor
Body Shape - Triangular bodied and round bodied needles cannot be securely grasped in a needle holder and are therefore relatively unstable in a with the potential for unwanted and traumatic slipping and twisting. By top-and bottom flattening the body of a needle, the needle’s security in the needle holder is greatly enhanced.
Ribs - Longitudinal grooves that match and are gripped by the serrations in the jaws of needle holders add an additional element of security.