Lesson 17: Introduction to Suture Materials and Surgical Needles and Biosecurity and Biosafety

What are the key properties of suture materials?

1. tensile strength

2. pliability

3. memory

4. surface friction

5. knot security

6. tissue reactivity

How does a taper point needle appear on packaging?

circle

How does a cutting point needle appear on packaging?

right side up triangle

How does a reverse cutting needle appear on packaging?

upside down triangle

How do you determine which size suture to use?

size of patient

What are the characteristics of monofilament suture material?

1. single strand, less drag

2. decreased knot security

3. weakened by kinking ot crushing by instruments

What might happen with a suture with low knot security?

you might need more throws

What are the characteristics of multifilament suture material?

1. braided

2. more pliable

3. higher infection risk

4. better knot security

5. more tissue drag

When should you NOT use multifilament suture?

infected/contaminated environments

What can multifilament suture form in the urinary bladder?

NIDUS for CALCULI formation

What are the characteristics of barbed suture material?

1. grip tissue, distribute tension evenly

2. close incision without knots

What are the characteristics of absorbable suture material?

loses >50% strength in

What are the characteristics of non-absorbable suture material?

retains >50% strength >60 days

How is suture material enzymatically digested?

enzymes produced by inflammatory cells attack collagen structure and break down peptide bonds

What kind of fibers cause more tissue reactivity?

natural fibers

What is the result of significant tissue reactivity during enzymatic digestion of natural fibers?

edema, redness, tissue reaction

What is hydrolysis of suture material?

water molecules cleave/break the polymer chains of synthetic suture

Which form of suture absorption has a low inflammatory response leading to less tissue reaction?

hydrolysis

What is the United States Pharmacopoeia (USP) suture sizing system?

uses numbers and zeros; more zeros = smaller diameter (e.g., 5-0 is thinner than 2-0). Larger whole numbers (e.g., 1, 2) = thicker sutures

What is the European Pharmacopoeia (EP gauge) suture sizing system?

directly reflects diameter in tenths of a millimeter (e.g., metric 2 = 0.2 mm)

Where does the needle body extend from?

point to swage.

What is the swage?

attachment of suture material to the needle, crimped end

What is a taper point needle?

tapers to a point with a round smooth shaft

What is a taper point needle best for?

soft tissue

What is a cutting point needle?

triangular tip, apex forms cutting surface

What are cutting point needles best for?

tough tissue such as skin

What is a reverse cutting needle?

similar to cutting but the cutting edge faces downwards to decrease chances of suture pull though

What is tensile strength?

ability for suture to hold tissue together (apposition)

Does a local inflammatory response to suture material necessarily indicate infecion?

no

What factors affect tissue reaction to suture?

1. Suture material (synthetic vs. natural)

2. Type of tissue being repaired

3. Suture size

4. Length of time the suture is in place

What are the common brands of Polyglactin 910 absorbable suture material?

Vicryl® (+/- Plus), Vicryl Rapide®, Surgicryl®

What are the properties of Polyglactin 910 absorbable suture material?

1. Synthetic, braided

2. Minimal tissue reaction

3. ~50% strength at 2-3 weeks

4. Fully absorbed in 56-70 days

5. Vicryl Rapide loses strength much faster (7-10 days)

What are the common veterinary uses for Polyglactin 910 absorbable suture material?

1. Rapid healing tissues (oral cavity, periocular skin)

2. Subcuticular closures

3. Muscle

4. Ligatures

5. Small animal soft tissue surgery

What are the limitations of Polyglactin 910 absorbable suture material?

1. avoid use in infected fields because it is braided

2. not ideal for long term healing

What are the common brands of Polydioxanone (PDS) absorbable suture material?

PDS II®, Surgicryl PDS®, Monodiox®

What are the properties of Polydioxanone (PDS) absorbable suture material?

1. Synthetic, monofilament

2. Very low tissue reactivity

3. Slow absorption

4. Retains ~70% strength at 2 weeks, ~50% at 4 weeks

5. Complete absorption in 180 days

6. Stiff handling, more "memory"

What are the common veterinary uses of Polydioxanone (PDS) absorbable suture material?

1. Linea alba

2. Fascia (large animals)

3. Tendons

4. GI surgery (hollow organs)

What are the limitations of Polydioxanone (PDS) absorbable suture material?

1. Requires secure knotting

2. Slightly harder to handle

What are the common brands of Polyglecaprone 25 absorbable suture material?

Monocryl®, Monocryl Plus®. Monosyn®

What are the properties of Polyglecaprone 25 absorbable suture material?

1. Synthetic, monofilament

2. Very low tissue reaction

3. Highest initial tensile strength (~50-60% at 1 week, ~20-30% at 2 weeks)

4. Complete absorption in 90-120 days

5. Excellent handling

What are the common veterinary uses of Polyglecaprone 25 absorbable suture material?

small animal soft tissue SQ and intradermal closure

What are the limitations of Polyglecaprone 25 absorbable suture material?

not suitable for high-tension or slow-healing tissues

What are the common brands of Polyglyconate absorbable suture material?

Maxon®

What are the properties of Polyglyconate absorbable suture material?

1. Synthetic, monofilament

2. High tensile strength

3. Slow absorption (≈180 days)

4. Minimal tissue reactivity

5. Good knot security

What are the common veterinary uses of Polyglyconate absorbable suture material?

1. Abdominal wall

2. Fascia

3. Orthopedic soft tissues

What are the common brands of natural absorbable Catgut suture material?

Plain catgut and Chromic catgut (chromic acid)

What are the properties of natural absorbable Catgut suture material?

1. Natural, twisted

2. Submucosa of sheep intestine or serosa of bovine intestines (>90% collagen)

3. Enzymatic digestion

4. High tissue reactivity (severe in cats)

5. Chromic lasts longer than plain

6. Plain gut 100% by 10 days

7. Chromic gut 60% by 28 days, 80% by 60 days

What are the common veterinary uses of natural absorbable Catgut suture material?

ligatures (limited use today)

What are the limitations of natural absorbable Catgut suture material?

1. Inflammation

2. Variable absorption

3. Largely replaced by synthetics

What are the properties of Nylon (Polyamide) non-absorbable suture material?

1. Synthetic, mono/multifilament

2. Very low tissue reactivity

3. Highly resistant to degradation

4. Good knot security

5. Minimal absorption

What are the common veterinary uses of Nylon (Polyamide) non-absorbable suture material?

1. Skin closure (large animal)

2. Ophthalmic and neurosurgery

3. Ligation of blood vessels

What are the limitations of Nylon (Polyamide) non-absorbable suture material?

1. Memory (difficult to handle, needs careful knot tying)

2. Can cause tissue irritation if not placed properly

3. Contraindicated in hollow organs

What are the properties of Polypropylene non-absorbable suture material?

1. Synthetic, monofilament

2. Very low tissue reactivity

3. Excellent tensile strength

4. Non-degradable

What are the common veterinary uses of Polypropylene non-absorbable suture material?

1. Vascular surgery

2. Cardiothoracic surgery

3. Joint repair

4. Neurosurgery

5. Long-term skin closure (especially in large animals)

What are the limitations of Polypropylene non-absorbable suture material?

1. Inferior knot security

2. High memory, can be stiff

3. Permanent foreign body

What are the properties of Silk non-absorbable suture material?

1. Natural, braided

2. Strong initial tensile strength

3. Absorbed slowly (~2 years)

4. Excellent handling

5. High tissue reactivity (due to natural composition)

6. Prone to infection in contaminated wounds

What are the common veterinary uses of Silk non-absorbable suture material?

1. Cardiovascular surgery

2. Ophthalmic

3. Ligatures

4. Veterinary skills lab

What are the limitations of Silk non-absorbable suture material?

1. High risk of chronic inflammation and infection (braided structure)

2. Contraindicated for hollow organs

3. Superseded by synthetic sutures

What is a significant limitation for silk suture use in the bladder and gallbladder?

potential nidus for calculus formation

What are the properties of stainless steel non-absorbable suture material?

1. Synthetic, monofilament

2. Exceptionally high tensile strength

3. Non-absorbable (retains strength indefinitely)

4. Excellent biocompatibility with minimal tissue reaction

5. Very stiff, can be difficult to handle and tie

What are the common veterinary uses of stainless steel non-absorbable suture material?

1. Orthopedic surgery

2. Joint stabilization (e.g., cruciate ligament repair)

3. Suture anchors for tendon and ligament repair

What are the limitations of stainless steel non-absorbable suture material?

1. Difficult to handle

2. Harder to knot securely (requires experience)

3. Painful and can cause longterm irritation in certain cases

What are the properties of polyester non-absorbable suture material?

1. Synthetic, non-absorbable

2. Braided, +/- Coating (silicone)

3. Very strong and durable

4. Good knot security

5. Low tissue reactivity

6. Some tensile strength retention even after a year

What are the common veterinary uses of polyester non-absorbable suture material?

1. Orthopedic surgery (tendon/ligament repair)

2. Vascular surgeries

3. Ligation of large blood vessels

4. Cardiovascular procedures (e.g., aortic or vena cava repairs)

What are the limitations of polyester non-absorbable suture material?

1. Tissue reactivity (compared to monofilament)

2. Higher infection risk because its braided

3. Permanent foreign body

4. Contraindicated in hollow organs

How long does it take for loss of tensile strength of quick absorption suture material?

7-14 days

How long does it take for loss of tensile strength of moderate absorption suture material?

2-4 weeks

How long does it take for loss of tensile strength of slow absorption suture material?

6+ weeks

How long does it take for loss of tensile strength of non-absorbable suture material?

permanent or years

What are some examples of quick absorption suture material?

Plain Gut, Vicryl Rapide

What are some examples of moderate absorption suture material?

Chromic Gut, Vicryl, Monocryl

What are some examples of slow absorption suture material?

PDS (Polydioxanone), Maxon

What are some examples of non-absorbable suture material?

Nylon, Prolene, Polyester, Silk

What are some common tissue applications of quick absorption suture material?

oral/ocular mucosa

What are some common tissue applications of moderate absorption suture material?

1. subcutaneous tissue

2. skin

What are some common tissue applications of slow absorption suture material?

1. fascia

2. tendon repairs

3. abdominal wall closure

What are some common tissue applications of non-absorbable suture material?

1. skin (large animals)

2. vascular anastomosis

3. tendon repair

What are some suture complications?

1. surgical site infection

2. dehiscence

3. seroma

What is wicking?

movement of fluid and bacteria into spaces between multifilament fibers, which can cause or sustain infection

What is dehiscence?

failure of sutures to hold incision closed

What is a seroma?

most associated with failure to close underlying dead space

What is the benefit of swaged (eyeless) surgical needles?

reduced tissue trauma

What are the design features of taper (round) point needles?

smooth, round body that spreads tissue fibers without cutting

What are the design features of cutting needles?

triangular shape with cutting edge on the inner curve

What are the design features of reverse cutting needles?

triangular with cutting edge on the outer curve; stronger than cutting needle

What are the design features of blunt point needles?

rounded tip; separates rather than penetrates tissue

What kind of tissues are taper (round) point needles used on?

soft tissues: bowel, muscle, fascia, peritoneum

What kind of tissues are cutting needles used on?

tough tissues like skin

What kind of tissues are reverse cutting needles used on?

skin, fascia, tendon

What kind of tissues are blunt point needles used on?

friable tissue: liver, spleen, obstetrics

What is the trauma level of taper (round) point needles?

least traumatic

What is the trauma level of cutting needles?

more traumatic

What is the trauma level of reverse cutting needles?

less traumatic than cutting, but still traumatic

What is the trauma level of blunt point needles?

minimal trauma and reduced needlestick risk

What kind of suture material is good for areas that need strong suture that lasts for a long time (ex: linea alba, tendons)?

PDS

What is important to remember about cats and catgut?

can cause severe tissue reactions (do not use)

What is the least reactive suture material?

monocryl

What is the most reactive suture material?

catgut

What is the fastest healing tissue?

oral mucosa

What suture material is best for extracapsular lateral suture repair?

nylon