LESSON 5

SURGICAL SUTURE MATERIALS.

SURGICAL INSTRUMENTS AND NEEDLES SUTURING.

DRESSINGS MATERIALS.

Surgical sutures

Ideal suture should be:

ü Easy to handle

ü Have minimally reaction in tissue

ü Inhibits bacterial growth

ü Holds securely when knotted

ü Resist shrinking in tissue

ü Is noncapillary, nonallergenic, noncarcinogenic and nonferromagnetic

ü Absorbs with minimal reaction after tissue has healed

NOTE: Such an ideal suture does not exist.

CHARACTERISTICS OF SUTURES

Suture size

The smallest diameter suture that will adequately hold the mending wounded tissue should be used in order to minimize trauma as the suture passed through the tissue. And also to reduce the amount of foreign material left in the wound. A suture should not be stronger than the sutured tissue.

The most commonly used standard for suture size is the USP (United States Pharmacopoeia), which denotes dimension from 10-0 the smallest and 7 the largest.

Flexibility

The flexibility of suture is determined by its torsional stiffness and diameter, which influence its handling and use.

Surface characteristic

The surface characteristics of suture influence the ease with which is pulled through tissues (i.e., the amount of friction or ″drag″) and the amount of trauma caused.

Capillarity

Capillarity is the process by which fluid and bacteria are carried into the interstices of multifilament fibers. Capillary suture materials should not be used in contaminated or infected sites. Coating reduces capillarity of some sutures.

Knot tensile strength

Knot tensile strength is measured by the force that suture strand can withstand before it breaks when knotted.

Relatively knot security

The knot-holding capacity of suture material is the strength required to untie or break a defined knot by loading the part of the suture that forms the loop.

Sutures material may be classified:

According to their origin:

a) organic

b) synthetic

c) metallic

According to their behavior in tissue:

a) absorbable (phagocytized or hydrolyzed)

b) nonabsorbable

According to their structure

a) monofilament

b) multifilament

Monofilament sutures:

Monofilament sutures are made of a single strand of material.

Advantage

ü have less tissue drag than multifilament suture,

ü do not have interstices that may harbor bacteria.

Disadvantage

ü with thicker threads the wiriness that is a characteristic of all monofilament threads impairs handling and in particular renders knot-tying more difficult,

ü care should be used in handling because nicking or damaging them with forceps or needle holder weakens them and predispose them to breakage.

Multifilament suture

Multifilament sutures are made of several strands of suture that are twisted or braided together.

Advantage

ü are more pliable and flexible than monofilament sutures,

ü results in considerably better knot holding security.

Disadvantage

ü the longitudinal orientation of the individual filaments within the thread results in relatively high capillarity, but the capillarity of braided threads is less than that of twisted threads.

ü have a rough surface that impairs passage through tissue.

Multifilament threads are generally coated. The coating smoothes out the irregular surface and thus facilitates passage through tissue without impairing knot-holding security. Coated multifilament threads are less stiff and wiry than monofilament threads. The coating also reduces capillarity.

A. ABSORBABLE SUTURES

1. Natural

i. Natural suture are catgut of biological origin and are protein in nature, their absorption and digestion is by proteolytic enzymes present in tissue fluid. The source is submueosa of sheep or serosa of intestine. Their fibres are then chrome tanned to delay absorption and twisted under tension and polished to achieve monofilament profile. Chrome tanning also reduces inflammatory response to tissue. Absorption is variable and has a range of 60-120 days. In some cases catgut been found in wound even after 3 years. Despite its unpredictable and variable absorption, very little strength is reported after 8-9 days. In tissue like stomach, duodenum and ileum there is functional loss of strength after 24-hours of implantation and has lost effective tensile strength by 30-32 days.3 Plain catgut loses its straight tensile strength by 53% and chromic catgut by 40% when knotted. Serilization is achieved by Gamma radiation or ethylene oxide. Packing is done in fluid which retains its ideal handling characteristics, the fluid is 89% Isopropanol, 10% water and 1% Triethanolamine.

Uses:

- Rapidly healing tissue

- Hysterectomy

- Caesarian Section

- General Surgery

- Ophthalmology

ii. Collagen is also of biological origin from ox Achilles tendom; rolled monofilament, undyed and uncoted.

iii. Fascia Lata

2. Synthetic

i. Polyglycolic acid (PGA) is available in two forms, the braided form is “Dexon” while the monofilament is “Maxon”. It is mane made homopolymer of glycolide. In monofilament form the flexibility in insufficient, therefore, braided form is used for general surgical use. Recently special coating of monofilament with polycaprolacton and glycolide has provided sufficient flexibility. The straight pull tensile strength is 1.2 times greater than catgut but knot pull tensile strength is much better. Properties of the PGA sutures are:

- Loss of strength on knotting is only 20%

- Retain strength in wetting

- Knot slippage is rare

- Does not swell

- Absorption is by hydrolysis, uniform and predictable, it begins on 10^th day and is complete by 120 days.

Uses:

ü Orthopaedics

ü Surgical Oncology

ü Debilitated Patients

ü Gen/Gyn (Fascia)

ü Plastics

ii. Polygalactin 910 “Vicryl”. A man-made copolymer of glycolide and lactate, is available in braided form. To reduce the tissue drag, the braided filaments are coated with calcium stearate, glycolide and lactate. Absorption is uniform and predictable, commencing at 40 days and complete between 60 and 90 days after implantation. Strength is greater than P.G.A. especially after 14 days. The inflammatory response is mild to moderate. Sterilization is by ethylene oxide.

Uses:

- Rapidly healing tissue

- Episiotomy Repair

- Skin Closure (except face)

- Scalp

- Under casts

- Intra-oral mucosa

iii. Polydioxanone “PDS”: PDS is man-made new copolymer, a polyester of paradioxanone, which is melt and a monofilament profile is achieved. It is the only suture which retains unique flexibility in mono filament form. Its strength is greater than that of all commonly used monofilament sutures other than steel. More than 80% strength is retained at 2 weeks, 70% at 4 weeks and more than 30% at 8 weeks. Absorption is by hydrolysis, beginning at 90 days and complete in 210 days. Tissue reaction is milder than other sutures. Handling properties compare favorably with those of catgut and knot security is good. Its monofilament profile makes it particularly useful in potentially infected tissues like colon, biliary system, stomach etc. Sterilization is by ethylene oxide.

Uses:

- long term healing applications (diabetics / oncology)

- Plastics

- Orthopaedics

iv. Polyglyconate – “Monocryl”: it is a man-made copolymer of glycolide and caprolactone, in ratio of 72:25; it has clear, undyed monofilament.

Uses: - Skin / Ob-Gyn / General / Urology

v. Polyglyconate – “Maxon”: it ia man-made copolymer of 1,4-dioxane 2,5-dione and trimethylene carbonate; monofilament, dyed or undyed.

В. NON-ABSORBABL SUTURES

I. Natural

i. Silk: It is derived from thread spun by larva of silk worm by degumming of surface albumin layer. The braided multifilament, dyed or undyed, coated or uncoated silk is known for excellent handling properties and knot security. Marked inflammatory reaction, tissue drag and braiding are its main disabilities as braiding induces capillary attraction and hence harbor the infective agent in interstices. Tissue drag is overcome by waxing or silicon coating reducing knot security, a third throw is always necessary. Fragmentation occurs and all tensile strength is lost by 9 months Sterilization is by Gamma radiation, however boiling and autoclaving may also be used.

Uses: Virtually all specialties

ІІ. Cotton. It is cellulose in nature and occurs as multifilament. Most of the properties are similar to those of silk except that strength of cotton increases when wet, where as silk loses 20% of strength when wet. Cotton is cheaper than all other sutures. It is available as dyed or undyed and uncoated.

iii. Linen, It derived from falx plant; twisted multifilament, dyed or undyed and uncoated.

2. Synthetic.

і. Polyamide: "Nylon". It can be monofilament or multifilament dyed or undyed, generic name Nylon 6 or Nylon 66; trade name Ethilon (Uses: - ophthalmology - Skin Closure) or Dermalon (monofilament) and Nurolon (braided) or Surgilon (braided nylon). In monofilament form there is decreased tissue reaction, strength is remarkable and 16% strength is still there even after one year. It is almost inert in nature, though a case has been reported by R-J-Schechcer of a Nylon toxicity which occurred after 4-months in a patient who under went vitrectomy. The sign and symptoms disappeared after removal of sutures.

Its disadvantages are poor handling, poor knotting, and its "Memory to untie" where as in braided form, although the knotting and handling difficulties are overcome to some extent, there remains some disadvantages like increased tissue reaction, loss of strength within 6 months and early fragmentation. It may need removal in sepsis. Sterilization is by Gamma radiation but can tolerate autoclaving up to three times.

ii. Polyester; monofilament or multifilament, dyed or undyed, coated or uncoated; trade name Ethibond (polybutylate coating) or Tri. Cron (silicon coating), and Mersilene orDacron (uncoated).' Polyesters are known for having high and permanent tensile strength, inducing only modest tissue reaction and having good knot security. They are widely used in cardiovascular surgery. In braided form, the strands tend to adhere, resulting in poor handling and difficult knotting, the reason for coating with polybutylate. This brings smoothness to the fibres but corn promises knot security.

Uses:

- Tendon Repair

- Ophthalmology (monofilament)

iii. Polybutylester: monofilament, dyed or un-dyed, polybutylene terphthalate and polytetramethylent ether glycol; trade name Novafil. Its "Mesh" forms are used for pair of vascular defects and Hernias.

iv. Polyethylene: It is available in monofilament form as a strong suture, induces minima] tissue reaction, excellent knotting and handling due to its soft surface. Mesh form is also available. Progressive loss of strength occurs by fragmentation. Sterilization is done by Ethylene oxide or Gamma radiation. It melts at 132 С so autocaving can not be done.

v. Polypropylene: monofilament dyed or undyed; trade name is Prolene. It has a permanent high tensile strength, the most inert suture, better handling properties of knot security than Nylon. It has no memory to untie. Fragmentation does not occur within tissues. Its mesh forms are used in the repair of prolapse rectum. When used to suture blood vessels the blood loss is much less. Available in vivid blue colour which facilitates visualization during surgery. Sterilization is by Ethylene oxide.

Uses:

- peripheral vascular & coronary artery bypass (85% market share)

- skin closure

vi. PVDF. (Polyvinylidene fluoride) monofilament, dyed or undyed. Its trade name is Trofilene.

Uses: Peripheral Vascular

Coronary Artery Bypass

(Skin stage two)

С. NON ABSORBABLE METAL SUTURES.

Stainless steel. Maintain tensile strength indefinitely- Monofilament or muftifilament.

i. Vitadium

ii. Tantalum

iii. Silver

D. SURGICAL STAPLES AND CLIPS

i. Absorbable. The concept of Viscerosynthesis.

ii. Non-Absorbable

SURGICAL NEEDLES

Requirements to surgical needles:

· Minimal tissue trauma

· High sharpness (acuity)

· Corrosion resistance

· High strength

· Stable shape

· Abrasion resistance

· Smooth profile

ANATOMY OF A NEEDLE

Surgical needles are divided in two groups:

· Traumatic needles

· Atraumatic needles

Traumatic needles - are needles with holes or eyes which are supplied to the hospital separate from their suture thread. In traumatic needles with eyes, the thread comes out of the needle's hole on both sides. When passing through the tissues, this type of suture rips the tissue to a certain extent, thus the name traumatic.

Traumatic needle

Atraumatic needles with sutures - comprise an eyeless needle attached to a specific length of suture thread. Important thing is that the suture end of a swaged needle is smaller than the needle body.

Atraumatic needle with attached suture thread

Needles shapes:

1. Straight – skin, nervs, GI tract, tendons, blood vessels, etc.

2. Halfcurved – skin (rarely used one)

3. Curved – according to curve degree are divided:

· 1/4 circle – eye, microsurgery,

· 3/8 circle – used for the most body structures,

· 1/2 circle - used for the most body structures,

· 5/8 circle – urinary and reproductive system.

4. Combine needle – anterior segment of the eye.

Point and body shape:

Taper – taper point and round or quadrangular body (cross section) – aponeurosis, muscles, nerves, peritoneum, blood vessels, valves.

· also called round needles

· point tapers to a sharp tip

· pierce and spread tissue

· without cutting it

· needle body flattens to an oval or rectangular shape

Application

ü G.I. Tract

ü urogenital tract

ü vessels

ü biliary tract

ü peritoneum

ü fascia dura

ü nerve,muscle

ü myocardium

ü subcutaneous fat

Blunt - blunt point and flat body (cross section) – bowels, kidney, spleen, liver.

· dissect friable tissue rather

· than cutting it

· taper body with rounded blunt

· point

· used for increased safety in

· OB/GYN procedures when

· working in deep cavities with

· space and visibility limitations

Application

ü blunt dissection (friable tissue)

ü fascia

ü intestine

ü kidney,

ü liver,spleen

ü ligating incompetent cervix

Triangular – triangular point and flat or quadrangular body (cross section). If the cutting side of triangular is upward this type of needle is called conventional (skin, sternum), and if it’s downward reverse cutting (fascia, ligaments, skin, tendons).

· triangular point with third cutting

· edge on convex side of needle

· curvature

· configuration provides the needle

· with greater strength

· danger of tissue cut out

· hole leaves a wide wall of tissue for

· the suture to be tied against

Application

ü skin

ü fascia

ü ligament

ü tendon sheath

ü nasal cavity

ü pharynx

ü oral cavity

Tapercut - small triangular cutting point and flat body (cross section) – fascia, ligaments, uterus, oral cavity and etc.

· combine the features of a taper point needle and reverse cutting edge tip

· 3 cutting edges extend 0.8mm back from the trocar point and merge into a round taper body

· point penetrates dense, tough tissue, round body prevents cutting into tissue

Application

ü Calcified tissue

ü bronchus

ü trachea

ü nasal/oral cavity

ü fascia

ü periosteum

ü perichondrium

ü uterus,ovary

ü tendon,ligament

Bandaging Materials

Fingertip Bandage

The fingertip bandage has a narrow center with wide adhesive flaps. The narrow "waist" allows it to cover a curved surface without wrinkling. Some uses for this bandage are:

1. protecting a shallow laceration of the fingertip or thumb tip

2. covering a cut or abrasion between the fingers or toes

3. protecting a loose fingernail or toenail (partial nail avulsion)

4. covering a small chin or nose abrasion

A laceration may be treatable at home if:

1. there is no protruding fat (see the section on injuries)

2. the laceration stops bleeding rapidly (within ten minutes)

3. the edges appear to match perfectly

4. the cut doesn't open with traction on nearby skin

5. the edges don't separate with use of the injured part

6. the area is not "tricky" or critical (such as face, genitals or knuckle)

7. there is no numbness, weakness, or difficulty moving the injured area

Knuckle Bandage

The knuckle bandage has four adhesive flaps. The flaps allow the bandage to remain secure on a curved or moving area. Some uses for this bandage are:

1. protecting a shallow laceration on a knuckle

2. covering an abrasion on a "curve" like the heel or chin

3. covering an abrasion or cut on the back of the elbow

4. covering any area where the skin stretches or moves

Large Plastic Bandage

The large plastic bandage is used to cover a wound of intermediate size. This usually will be a skin surface injury such an abrasion or superficial burn. To cover and protect, the injury area must be fairly flat.

Sample uses for this bandage could include:

1. an open wound (such as an abrasion) on the thigh

2. a scrape on the shoulder

3. a small burn on the trunk or thigh

A bandage of this type does NOT provide adequate protection for a large laceration, because it doesn't provide any compression or traction to keep the cut closed.

Plastic Bandage Strip

A plastic bandage can be used to cover a simple, small wound. The wound must NOT need padding or compression. A plastic bandage should only be used over a non-moving area -- for example, the space between the knuckles on the shaft of a finger is OK; between the fingers or over a knuckle is NOT.

Sample uses of plastic strips include:

1. a small shallow puncture wound that is not bleeding

2. A partial thickness laceration on a finger (not over the knuckle)

3. a tiny abrasion on a non-moving area

Plastic strips are NOT appropriate for wounds where the skin stretches with motion -- for example on the back of the elbow or underside of the wrist. They're NOT to be used on lacerations that require intervention to close.

Cloth bandages are more flexible over moving parts. But they tend to fray and unroll from the wound. The adhesive on a cloth bandage is more likely to leave a residue. So for most cuts, a plastic bandage is a better choice. But where the cloth bandage works, it's wonderful.

Butterfly Bandage

A butterfly bandage is used to pull the edges of a short laceration together. Typically, a butterfly is used for a small cut that tends to gape a bit. The edges of the cut must be sharp, not rough or irregular. (See the laceration information in the injuries section.)

Because the butterfly dressing does NOT stretch, it can only be used where the skin will not stretch or shift while the wound heals. In general, steri-strip closure is preferred to butterfly bandages.

To place the butterfly, the laceration edges are pushed together. The strip is placed across the wound (long direction of the strip aiming 90 degrees opposite the long direction of the cut). One side is pressed firmly into place, with the narrow waist lying directly over the cut. Then the second "paddle" is pushed onto the skin. The butterfly is left in place while the cut heals. It's usually best to protect the butterfly by covering it with a gauze pad and a kling wrap.

Wound Closure Tape

Steri-Strips (TM 3M) are wound closure tapes. They are ideal for partial thickness cuts. Steris are more flexible than a butterfly bandage, and can close longer lacerations.

After cleaning the laceration, dry the surrounding skin. Apply benzoin tincture to the skin (don't get it in the cut). Cut the strips, then push the laceration edges together. Place strips across the wound (long direction of the strip aiming 90 degrees opposite the long direction of the cut). Protect with gauze (without antibiotic ointment) and a wrap.

The steris can be left in place while the heals. Steri-Strips may not provide good long-term protection in areas where the skin shifts or stretches (underside of the wrist, back of the elbow). The only disadvantage is: they're not as easy to find as butterfly bandages, and they're more expensive.

Non-adherent Pad

Non-adherent pads are useful to cover open wounds such as burns and abrasions. The brand known best is Telfa. The pad keeps the dressing from sticking to the wound.

After cleaning the wound, antibiotic ointment is applied. Be sure the patient isn't allergic to the antibiotic. The non-stick pad is placed next, then a gauze pad to cushion and protect. A kling wrap keeps

Gauze Pads

Gauze pads cushion and protect wounds. They also prevent dryness in an open wound. (The gauze pad shouldn't be placed directly on an open wound, because it will stick.) The gauze pads have a loose weave, so blood and fluids can ooze pass through to be absorbed.

To construct a dressing, first place a non-stick pad. Put the gauze directly over top. Bind it down with a roller gauze (kling wrap). If you need compression (either to prevent swelling or bleeding, or to keep the bandage in place), add an elastic wrap or Coban wrap. Otherwise, apply just enough tape to keep the dressing in place.

Padding Roll Gauze

Padding roll gauze is very useful to cushion large wounds. It's often called "Kerlix," which is a specific brand. It can be used in place of a kling wrap in the dressing, and for many wounds provides enough padding that gauze pads are not required. It absorbs ooze or blood, and prevents dryness in an open wound.

The padding roll gauze can also be used for compression dressings, for example to compress a sprained ankle. Apply it under the elastic wrap.

Sanitary Napkin

While lady bikers may carry a napkin or panty-liner for "emergencies" on the trail, there are other uses. The pad is sterile, absorbent, doesn't gum up and stick to the wound like toilet paper, and removes in one piece.

The pad makes an excellent temporary dressing. It can also be used as padding over an injury. It's large enough to give a sterile covering for a big wound, open fractures, or exposed viscera.

Trauma Dressing

The multi-trauma dressing can be used as padding, or as coverage. Coming in various sizes, these dressings unfold to cover (for example) the entire chest or abdomen.

The large size makes it useful for covering large areas of burn or abrasion while you travel to a medical facility. It can be used to cover exposed viscera. The dressing can be used to pad an injured arm or leg inside a splint.

Eye Pads

Eye pads are padded dressings for the eye. Eye pads are used to keep the eye shut following minor eye injuries such as a corneal abrasion. Depending on the depth of the eye socket, you may have to fold a pad in half to get the right amount of pressure.

The eye pad is taped in place. Run the bands of tape in an oblique direction: aim the top end for the middle of the front hairline and the bottom end for the angle of the jaw.

NOTE: You should NOT tape an eye pad over an eye that may have been punctured, or that has an impaled object. Instead, tape a paper drinking cup (with the open end facing the eye) over the eye.

Eye pads can also be used to provide local pressure over a wound. For example, to get control of bleeding in a puncture wound: place a couple of eye pads directly over it, secure it with a kling wrap, then use a compression wrap to apply pressure.

Roll Gauze

Roller gauze is used to secure dressings. This type of bandage is called a kling wrap. Pick a size appropriate to the wound, and to the body part you'll be bandaging. For example, a 1 inch roll is appropriate for fingers, while a 3 inch roll is about right for the upper arm.

To construct a dressing, first place a non-stick pad. Put the gauze pad directly over top. Bind it down with your roller gauze. If you need compression (either to prevent swelling or bleeding, or to keep the bandage in place), add an elastic wrap or Coban wrap. Otherwise, apply just enough tape to keep the dressing in place.

Padding Roll Gauze

Padding roll gauze is very useful to cushion large wounds. It's often called "Kerlix," which is a specific brand. It can be used in place of a kling wrap in the dressing. It absorbs ooze or blood, and prevents dryness in an open wound.

The padding roll gauze can also be used for compression dressings, for example to compress a sprained ankle. Apply it under the elastic wrap.

To construct a dressing, first place antibiotic ointment, then a non-stick pad. Put a gauze pad directly over top. Bind it down with the padding roll gauze. If you need compression (either to prevent swelling or bleeding, or to keep the bandage in place), add an elastic wrap or Coban wrap. Otherwise, apply just enough tape to keep the dressing in place.

Self-adherent Compression Bandage

Coban is a sample brand of self-adherent compression wrap. It sticks to itself, but does NOT stick to you. It can be used in many of the situations where you would use an elastic bandage (ace wrap). It's lighter and more conforming to your shape.

Example uses for Coban wrap would be:

1. compression of a healing shin muscle strain during sports

2. support for a healing wrist sprain at work

3. placement over a kling wrap to compress an injury

Coban does not rip. Use your scissors to cut it to the right length. In general, the wrap should be tightest at the end that's furthest from the heart.

Watch for signs that the wrap is too tight -- such as swelling, numbness, discoloration, or pain "downstream" from the wrap. Coban contains latex, to which some people are allergic.

Elastic bandage

Often called an "ace wrap," the elastic bandage is a roll of loose-weave cloth containing elastic strands. Wrapped around the extremity or trunk, it squeezes the underlying tissues.

Its uses are:

1. compression of injuries such as a sprain or bruise

2. elastic immobilization or support of injured parts

3. securing the dressing on a large open wound

4. control of bleeding in wounds or fractures

5. symptom control in rib fracture

Select a size appropriate to the injured part: adult wrist = 2 inch, adult ankle = 4 inch, adult thigh or chest = 6 inch. In general, the wrap should be tightest at the end that's furthest away from your heart. Be careful that the wrap doesn't cut off circulation -- watch for swelling, discoloration, increasing pain, or numbness "downstream" from the wrap.