Sutures are the stitches that doctors, and especially surgeons, use to hold skin, internal organs, blood vessels and all other tissues of the human body together, after they have been severed by injury or surgery. They must be strong (so they do not break), non-toxic and hypoallergenic (to avoid adverse reactions in the body), and flexible (so they can be tied and knotted easily). In addition, they must lack the so called "wick effect", which means that sutures must not allow fluids to penetrate the body through them from outside, which could easily cause infections.

Contents

1 Absorbable and nonabsorbable sutures o 1.1 Absorbable sutures o 1.2 Non-absorbable sutures

2 Surgical needles for use with sutures 3 Sizes of sutures 4 Suture techniques 5 Removal of sutures 6 Suture materials 7 Other facts

o 7.1 Tissue adhesives o 7.2 Antimicrobial sutures

8 See also

9 External links

[edit] Absorbable and nonabsorbable sutures

Sutures are divided into two kinds - those which are absorbable and will break down harmlessly in the body over time without intervention, and those which are non-absorbable and must be manually removed if they are not left indefinitely. The type of suture used varies on the operation, with a major criteria being the demands of the location and environment:

Sutures to be placed internally would require re-opening if they were to be removed. Sutures which lie on the exterior of the body can be removed within minutes, and without re-opening the wound. As a result, absorbable sutures are often used internally; non-absorbably externally.

Sutures to be placed in a stressful environment, for example the heart (constant pressure and movement) or the bladder (adverse chemical presence) may require specialized or stronger materials to perform their role; usually such sutures are either specially treated, or made of special materials, and are often non-absorbable to reduce the risk of degradation.

[edit] Absorbable sutures

Absorbable sutures are made of materials which are broken down in tissue after a given period of time, which depending on the material can be from ten days to eight weeks. They are used therefore in many of the internal tissues of the body. In most cases, three weeks is sufficient for the wound to close firmly. The suture is not needed any more, and the fact that it disappears is an advantage, as there is no foreign material left inside the body and no need for the patient to have the sutures removed.

Absorbable sutures were originally made of the intestines of sheep, the so called catgut. The manufacturing process was similar to that of natural musical strings for violins and guitars, and also of natural strings for tennis racquets. The inventor, a 10th century surgeon named al-Zahrawi reportedly discovered the dissolving nature of catgut when his lute's strings were eaten by a monkey. Today, gut sutures are made of specially prepared beef and sheep intestine, and may be untreated (plain gut), tanned with chromium salts to increase their persistence in the body (chromic gut), or heat-treated to give more rapid absorption (fast gut). However, the major part of the absorbable sutures used are now made of synthetic polymer fibers, which may be braided or monofilament; these offer numerous advantages over gut sutures, notably ease of handling, low cost, low tissue reaction, consistent performance and guaranteed non-toxicity. (In Europe and Japan, gut sutures have been banned due to concerns over bovine spongiform encephalopathy, although the herds from which gut is harvested are certified BSE-free.) Each major suture manufacturer has its own proprietary formulations for its brands of synthetic absorbable sutures; various blends of polyglycolic acid, lactic acid or caprolactone are common.

In rare cases, absorbable sutures can cause inflammation and be rejected by the body rather than absorbed.

[edit] Non-absorbable sutures

8 nonabsorbable sutures in a person's left thumb.

Nonabsorbable sutures are made of materials which are not metabolized by the body, and are used therefore either on skin wound closure, where the sutures can be removed after a few weeks, or in some inner tissues in which absorbable sutures are not adequate. This is the case, for example, in the heart and in blood vessels, whose rhythmic movement requires a suture which stays longer than three weeks, to give the wound enough time to close. Other organs, like the bladder, contain fluids which make absorbable sutures disappear in only a few days, too early for the wound to heal. Inflammation caused by the foreign protein in some absorbable sutures can amplify scarring, so if other types of

suture are less antigenic (ie, do not provoke as much of an immune response) it would represent a way to reduce scarring.

There are several materials used for nonabsorbable sutures. The most common is a natural fiber, silk, which undergoes a special manufacturing process to make it adequate for its use in surgery. Other nonabsorbable sutures are made of artificial fibers, like polypropylene, polyester or nylon; these may or may not have coatings to enhance their performance characteristics. Finally, stainless steel wires are commonly used in orthopedic surgery and for sternal closure in cardiac surgery.

Three sutures to a person's right arm, near the elbow.

[edit] Surgical needles for use with sutures

Traumatic needles are needles with holes or eyes which are supplied to the hospital separate from their suture thread. The suture must be threaded on site, as is done when sewing at home. Atraumatic needles with sutures comprise an eyeless needle attached to a specific length of suture thread. The suture manufacturer swages the suture thread to the eyeless atraumatic needle at the factory. There are several advantages to having the needle pre-mounted on the suture. The doctor or the nurse does not have to spend time threading the suture on the needle. More important, the suture end of a swaged needle is smaller than the needle body. 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. Nearly all modern sutures feature swaged atraumatic needles.

There are several shapes of surgical needles, including:

straight half curved or ski 1/4 circle 3/8 circle 1/2 circle 5/8 circle compound curve

Needles may also be classified by their point geometry; examples include:

taper (needle body is round and tapers smoothly to a point) cutting (needle body is triangular and has a sharpened cutting edge on the inside) reverse cutting (cutting edge on the outside) trocar point or tapercut (needle body is round and tapered, but ends in a small

triangular cutting point) blunt points for sewing friable tissues side cutting or spatula points (flat on top and bottom with a cutting edge along the

front to one side) for eye surgery

Finally, atraumatic needles may be permanently swaged to the suture or may be designed to come off the suture with a sharp straight tug. These "pop-offs" are commonly used for interrupted sutures, where each suture is only passed once and then tied.

[edit] Sizes of sutures

Suture sizes are defined by the United States Pharmacopeia (U.S.P.). Sutures were originally manufactured ranging in size from #1 to #6, with #1 being the smallest. A #4 suture would be roughly the diameter of a tennis racquet string. The manufacturing techniques, derived at the beginning from the production of musical strings, did not allow thinner diameters. As the procedures improved, #0 was added to the suture diameters, and later, thinner and thinner threads were manufactured, which were identified as #00 (#2-0 or #2/0) to #000000 (#6-0 or #6/0).

Modern sutures range from #5 (heavy braided suture for orthopedics) to #11-0 (fine monofilament suture for ophthalmics). Atraumatic needles are manufactured in all shapes for most sizes. The actual diameter of thread for a given U.S.P. size differs depending on the suture material class.

A wound before and after being closed by simple interrupted sutures

U.S.P.Designation

Collagenmetric

diameter(mm)

Synthetic absorbable

metric diameter(mm)

Non-absorbable

metric diameter

(mm)

American wire gauge

11-0 0.01

10-0 0.02 0.02 0.02

9-0 0.03 0.03 0.03

8-0 0.05 0.04 0.04

7-0 0.07 0.05 0.05

6-0 0.1 0.07 0.07 38-40

5-0 0.15 0.1 0.1 35-38

4-0 0.2 0.15 0.15 32-34

3-0 0.3 0.2 0.2 29-32

2-0 0.35 0.3 0.3 28

0 0.4 0.35 0.35 26-27

1 0.5 0.4 0.4 25-26

2 0.6 0.5 0.5 23-24

3 0.7 0.6 0.6 22

4 0.8 0.6 0.6 21-22

5 0.7 0.7 20-21

6 0.8 19-20

7 18

[edit] Suture techniques

Common suture stitching techniques include:

Simple Interrupted Stitch ( or running) Mattress Horizontal mattress Vertical mattress Figure 8 Continuous locking Subcuticular

[edit] Removal of sutures

Whilst some sutures are intended to be permanent, and others in specialized cases may be kept in place for an extended period of many weeks, as a rule sutures are a short term device to allow healing of a trauma or wound. According to about.com's article on nursing:[1]

"Different parts of the body heal at different intervals. Common time to remove stitches will vary: facial wounds 3-5 days; scalp wound 7-10 days; limbs 10-14 days; joints 14 days; trunk of the body 7-10 days. "Not all stitches must be removed. If a small area remains unhealed, notify the health care practitioner. Then if ordered, remove sutures from the healed area only."

(Further information on suture removal can be found here)

[edit] Suture materials

. Plain catgutChromic

catgut

Polyglycolicacid

(P.G.A.)

Polydioxanone (PDS)

Description Absorbable biological suture material. Plain is an absorbable suture made by twisting together strands of purified collagen taken from bovine intestines. The natural plain thread is precision ground

Absorbable biological suture material. Chromic is an absorbable suture made by twisting together strands of purified

It is a synthetic absorbable suture material. Braided synthetic absorbable multifilament made of polyglycolic

It is a synthetic absorbable suture material. Monofilament synthetic absorbable suture, prepared from the polyester,

in order to achieve a monofilament character and treated with a glycerol containing solution. Plain is absorbed by enzymatic degradation.

collagen taken from bovine intestines. Due to undergoing a ribbon stage chromicisation (treatment with chromic acid salts), the chromic offers roughly twice the stitch-holding time of plain catgut. The natural chromic thread is precision ground in order to achieve a monofilament character and treated with a glycerol containing solution. Chromic is absorbed by enzymatic degradation.

acid and coated with N-laurin and L-lysine, which render the thread extremely smooth, soft and knot safe.

poly (p-dioxanone).

Composition  ?Natural purified collagen

Polyglycolic acid

Polyester and poly (p-dioxanone)

Tensile strengthStrength retention for at least 7 days.

 ?  ?  ?

Structure Monofilament Monofilament Braided Monofilament

OriginBovine serosa surface finish.

Bovine serosa Synthetic

Synthetic through the critical wound

Treatment  ?

Treatment with a glycerol containing solution and chromic acid salts

Coated with magnesium stearate

Uncoated

Type of absorption

Proteolytic enzymatic digestion complete by 90 days.

Proleolytic enzymatic digestion complete in 70 days. Absorption by enzymatic digestion and starts losing tensile strength on implantation from 18–21 days of catgut chromic

Absorption by hydrolysis complete between 60 and 90 days. Always predictable and reliable

PDS

Tissue reaction

Moderate. Plain catgut enjoys lower tissue reaction as compared to chromicised.

Moderate.  ?  ?

Thread color Straw Brown Violet Violet

Size availableUSP 6-0 (1 metric) to USP 3 (7 metric).

USP 6-0 (1 metric) to USP 3 (7 metric).

USP 6-0 (1 metric) to USP 2 (5 metric)

USP 6-0 (1 metric) to USP 2 (5 metric)

Sterilization E.O. Gas. E.O. Gas E.O. gas. E.O. gas

Advantages

Very high knot-pull tensile strength, good knot security due to special excellent handling features

Very high knot-pull tensile strength, good knot security due to special surface finish, improved smoothness due to the dry presentation of the thread, excellent handling features

High initial tensile strength, guaranteed holding power through the critical wound healing period. Smooth passage through tissue, easy handling, excellent knotting ability, secure knot tying

Tensile strength retention, guaranteed holding power

Indications For all surgical procedures especially when tissues that regenerate faster are involved. General closure, ophthalmic, orthopedics, obstetrics/gynecology and gastro-intestinal tract surgery.

For all surgical procedures, especially for tissues that regenerate faster.

Subcutaneous, intracutaneous closures, abdominal and thoracic surgeries

PDS is particularly useful where the combination of an absorbable suture and extended wound support is desirable, pediatric

cardiovascular surgery, ophthalmic surgery

Contraindications

Not recommended for incisions that require the sustaining of the tissues for a prolonged period of time.

Not recommended for an incision that requires sustaining of the tissues for a prolonged period of time.

This suture being absorbable should not be used where extended approximation of tissue is required.

This type of suture being absorbable is not to be used where prolonged approximation of tissues under stress is required and/ or in conjunction with prosthetic devices

Precautions Special precautions should be taken in patients with cancer, anemia and malnutrition conditions. They tend to absorb the sutures at a higher rate. Cardiovascular surgery, due to the continued heart contractions. It is absorbed much faster when used in the mouth and in the vagina, due to the presence of microorganisms. Avoid using where long term tissue approximation is

It is absorbed much faster when used in the mouth and in the vagina, due to the presence of microorganism. Cardiovascular surgery, due to the continued heart contractions. Special precautions should be taken in patients with cancer, anemia and

Special precautions should be taken in elderly patients and patients with history of anemia and malnutrition conditions. As with any suture material, adequate knot security requires the accepted surgical technique of flat and

The PDS suture knots must be properly placed to be secure. Conjunctival and vaginal mucosal sutures remaining in placed for extended periods may be associated with localized irritation. Subcuticular sutures should be placed as deeply as

needed. Absorption is faster in infected tissues

malnutrition conditions. They tend to absorb this suture at a higher rate.

square ties.

possible in order to minimize the erythema and induration normally associated with absorption.

[edit] Other facts

[edit] Tissue adhesives

In recent years, topical cyanoacrylate adhesives ("liquid stitches") have been used in combination with, or as an alternative to, sutures in wound closure. The adhesive remains liquid until exposed to water or water-containing substances/tissue, after which it cures (polymerizes) and forms a flexible film that bonds to the underlying surface. The tissue adhesive has been shown to act as a barrier to microbial penetration as long as the adhesive film remains intact. Limitations of tissue adhesives include contraindications to use near the eyes and a mild learning curve on correct usage.

[edit] Antimicrobial sutures

Another recent development in wound closure involves the use of sutures coated with antimicrobial substances to reduce the chances of wound infection. While long-term studies are not yet available, preliminary results indicate that these sutures are effective at keeping bacteria out of wounds.

Classification by type of points

All types of scissors can have blunt or sharp blades (A: Sharp:Sharp, B: Blunt:Blunt).

All types can have either straight or curved blades.

Mayo and Metzenbaum

Mayo scissors (B) are used for cutting heavy fascia and sutures.

Metzenbaum scissors (A) are more delicate than Mayo scissors.

Metzenbaum scissors are used to cut delicate tissues.

Metzenbaum scissors have a longer handle to blade ratio.

Needle holder: Hinged (locking) instrument used to hold the needle while suturing tissue.

Good quality is ensured with tungsten carbide inserts at the tip of the needle holder.

Mayo-Hegar

Heavy, with mildly tapered jaws.

No cutting blades.

Scissors and Hemostats:

The thumb and ring finger are inserted into the rings of the scissors while the index and middle finger are used to guide the instrument.The instrument should remain at the tips of the fingers for maximum control.

   

This is the wrong way to hold the scissors. The ring finger should be inserted into the ring.

   

This is also the wrong way to hold the scissors. The tips of the scissors should be pointing upwards.

Thumb Forceps:Thumb forceps are held like a pencil.

Thumb Forceps are not called 'tweezers'.Thumb Forceps are not held like a knife.

Scalpels:The scalpel is held with thumb, middle and ring finger while the index finger is placed on the upper edge to help guide the scalpel.Long gentle cutting strokes are less traumatic to tissue than short chopping motions.

The scalpel should never be used in a "stabbing" motion.

Olsen-Hegar

Includes both needle holding jaw and scissors blades.

The disadvantage to having blades within the needle holder is the suture material may be accidentally cut

Senn

Blades at each end.

Blades can be blunt (delicate) or sharp (more traumatic, used for fascia).

Hohman

Levers tissue away from bone during orthopedic procedures.

Weitlaner

Ends can be blunt or sharp.Has rake tips.Ratchet to hold tissue apart.

Gelpi

Has single point tips.

Ratchet to hold tissue apart.

Handles

#3 Handle

#4 Handle

Handles and Blades

Blades #10, 11, 12, 15 fit the #3 handle.

Blades #22, #23 fit the #4 handle and are commonly used for large animals.

Disposable Scalpel

Towel clamps secure drapes to a patient's skin. They may also be used to hold tissue.

Backhaus Towel Clamp

Locking forceps with curved, pointed tips.

Forceps: consist of two tines held together at one end with a spring device that holds the tines open. Forceps can be either tissue or dressing forceps.

Dressing forceps have smooth or smoothly serrated tips.

Tissue forceps have teeth to grip tissue. Many forceps bear the name of the originator of the design, such as Adson tissue forceps.

Rat Tooth: A Tissue Forceps

Interdigitating teeth hold tissue without slipping.

Used to hold skin/dense tissue.

Adson Tissue Forceps

Small serrated teeth on edge of tips.

The Adsons tissue forceps has delicate serrated tips designed for light, careful handling of tissue.

Intestinal Tissue Forceps: Hinged (locking) forceps used for grasping and holding tissue.

Allis: An Intestinal Tissue Forceps

Interdigitating short teeth to grasp and hold bowel or tissue.

Slightly traumatic, use to hold intestine, fascia and skin.

Babcock: An Intestinal Tissue Forceps

More delicate that Allis, less directly traumatic.

Broad, flared ends with smooth tips.

Used to atraumatically hold viscera (bowel and bladder).

Sponge Forceps

Sponge forceps can be straight or curved.

Sponge forceps can have smooth or serrated jaws.

Used to atraumatically hold viscera (bowel and bladder).

 Hemostatic forceps: Hinged (locking) Forceps. Many hemostatic forceps bear the name of the designer (Kelly, Holstead, Crile). They are used to clamp and hold blood vessels.

Classification by size and shape and size of tips

Hemostatic forceps and hemostats may be curved or straight.

Kelly Hemostatic Forceps and Mosquito Hemostats

Both are transversely serrated.

Mosquito hemostats (A) are more delicate than Kelly hemostatic forceps (B).

Comparison of Kelly and Mosquito tips

Mosquito hemostats (A) have a smaller, finer tip.

Carmalt

Heavier than Kelly.

Preferred for clamping of ovarian pedicals during an ovariohysterectomy surgery because the serrations run longitudinally.

 

Doyen Intestinal Forceps

Doyen intestinal forceps are non-crushing intestinal occluding forceps with longitudinal serrations.

Used to temporarily occlude lumen of bowel.

Payr Pylorus Clamps

Payr pylorus clamp is a crushing intestinal instrument.

Used to occlude the end of bowel to be resected.

Disposable Paper GownADVANTAGES:Paper gowns are resistant to wetting so they are less permeable to bacteria. They are preferred for wet bloody surgery (equine abdominal surgery).Donning a new gown for each surgery and disposing of it at the end ensures sterility.DISADVANTAGES:Paper is less ecologically sound because it is not reusable.

Linen (cloth) GownsADVANTAGES:Linen gowns are both comfortable and reusable. Previously worn gowns can be autoclaved to regain sterility.DISADVANTAGES:Linen is a woven material so that when it becomes wet, bacteria can permeate through its interstices. Linen is not the gown material of choice for wet, bloody surgical procedures.

Plastic GownsADVANTAGES:Plastic is superior in its resistance to wetting and bacterial penetration. Plastic can be used to reinforce paper gowns during wet surgery (plastic sleeves for abdominal surgery).DISADVANTAGES:Plastic is extremely uncomfortable to wear because of the inability to shed heat and perspiration.

Wrap Around GownThe paper gown is also known as a wrap around gown. The ties "wrap around" the surgeon.

Front Sterile GownThe cloth gown is also known as a front sterile gown. The gown is just tied in the back.

Folding of a Gown for Sterilization

Hold the gown so that the outside is facing away from you. Place the outside right and left ties into the white tab. Down Load Video of this step.

Fold the gown in half lengthwise twice making sure that the inside of the gown is showing. Down Load Video of this step

Lie the gown on a table and fold in half lengthwise again. Then fold end to end twice. Down Load Video. The gown is folded in such a way that the top of the inside of the gown is presented when the sterile pack is unwrapped. This is the area grasped by the surgeon to begin donning the gown.

A sterile towel is included within the sterile gown pack. The towel is lifted away from the table and folded in half lengthwise. One hand and forearm are dried by one side of the towel. Always dry in the direction of hand to elbow so that contamination of the upper arm is not spread by the towel to the surgeon's hand. Down Load Video of Drying Hands

The second hand and forearm are then dried by the other side of the towel in the direction of hand to elbow. The towel is then discarded away from the surgeon, making sure that the towel doesn't contact the sterile gown.

Closed gloving is performed after the surgeon has donned his/her gown, but BEFORE the surgeon pulls his/her hands through the cuffs of the gown.

Step 1: An assistant opens the sterile pack of gloves and drops them into the sterile field.

Step 2: Left hand (within the gown) lifts the right glove by its cuff.

Step 3: Right glove is laid on the palm of the right hand (cuff to cuff with the gown sleeve) with fingers of the glove pointing toward the elbow and the thumb of the glove positioned on top of the surgeon's covered right thumb.

Step 4: The inside of the cuff of the glove is grasped by the right hand (still within the gown) and the left hand folds the cuff of the glove over the back of the right hand.

Step 5: The left had then pulls the cuff of the right glove and sleeve of the right gown towards the elbow as the right hand slides into the glove. Wait to adjust the glove until both gloves are on and sterility is ensured (left fingers may slip out of the gown while trying to adjust the right glove prematurely).

Step 6: With the gloved right hand lift left glove by its cuff and place on palm of left hand (aligned with the cuff of the gown), with glove fingers pointing toward the elbow and the left thumb of the glove over the covered left thumb of surgeon.

Step 7: Left fingers (still within the gown) grasp the inside of the glove and the right hand pulls left glove cuff over the back of the hand.

Step 8: Pull the glove cuff and gown sleeve toward elbow as left hand slides into the glove

Step 9: Now that both gloves are on, pull glove cuffs over gown sleeves and adjust gloves for comfort.

Step 1: An assistant opens the sterile pack of gloves and drops them into the sterile field.

Step 2: Lift right glove by grasping the inside of the cuff with left hand.

Step 3:Slide right hand into glove without touching the gown or the outside of the glove. Do not adjust glove or cuff until both gloves are on.

Step 4: Lift the left glove by sliding fingers of gloved hand in between the upturned cuff and outside surface of glove.

Step 5: With gloved fingers still under the cuff, slide the glove onto left hand and over the cuff of the gown.

Step 6: Now that both gloves are on, adjust the right glove by sliding fingers of left hand under the cuff that is still upturned and slide it over the cuff of the gown.