◊ Suture Materials & Suture Patterns ◊
Suture Materials & Suture Patterns
I-NEEDLES
1-Classification according to the eye
A-Closed eye needle: -
It resembles the household sewing needle with one or two eyes. Double strand of the suture passes through the tissue and causes much trauma
B-Swaged-on needle (Eyeless or Atraumatic needle): -
It is permanently attached to the suture, and causes minimal tissue trauma.
2-Classification according to the body or the shaft
A-Straight needle or long stemmed needle: -
Like flessa needle or household sewing needle. It is no longer be used.
B-Half curved needle: -
Half of the needle is curved and the other half is straight.
C-Curved needle: -
It is ¼, 3/8, 1/2, or 5/8 circle, and it is the most famous type of needles.
D-Hook needle (Heavy bound bodied): -
The needle resembles hook.
3-Classification according to the point and the shaft
A-Conventional cutting or conventional sharp needle: -
The point is sharp with the cutting edge being provided at the concave surface
B-Reverse cutting or reverse sharp needle: -
The same as above but the cutting edge is provided on the convex surface to minimize cutting of the tissue
C-Taper cut needle: -
The point is cutting but the body is round
D-Non-cutting needle (round needle): -
The point is round and the body is oval, and it causes minimal traumatization of tissue
E-Blunt point needle (Ethiguard blunt taper point): -
The tip of point is blunt
F-Spatulated needle: -
This type of needle has wide body in relation to the length of the needle and it has two cutting edges.
II-SUTURE MATERIALS
Suture materials are those filaments used to suture the edges of the wound to permit healing
CHARACTERISITICS OF IDEAL SUTURE MATERIAL
1-Maintain their strength until the wound has healed
2-Have minimal tissue reaction
3-Not favorable for bacterial growth
4-Non-capillary, non-allergic, and non-carcinogenic
5-Easily handled with good knot security
6-Cheap
Unfortunately, ideal suture material has not been found yet and surgeon should be familiar with advantages and disadvantages of suture material to be used.
1-Absorbable suture materials
A-Surgical catgut: -
It is a popular cheap suture material of collagen obtained from the submucosa of sheep or serosa of beef intestine, sterilized by gamma radiation and preserved in 85% alcohol, and can’t be re-sterilized. Plain catgut loses its strength rapidly (3-7 days). Chromic catgut is obtained by exposure of plain catgut to chromium salts that increases strength of the filaments, decreases tissue reaction, and prolongs duration of absorption (10-20 days).
Factors affect absorption rate
1-The diameter of the filaments
2-Exposure to gastric enzymes
3-Infection
4-Blood supply
As the knot-holding ability decreases when the suture material is wet, the ends should be left slightly longer to minimize the chance of knot untying. However, this type of suture material is a protein and has high tissue reaction when compared with synthetic forms.
B-Collagen: -
It is a natural suture material related somewhat to catgut, and obtained from the flexor tendons of steers.
Advantages:
1-Smoother
2-Causes less inflammation than catgut
3-More uniform than catgut
4-It has less fray tendency and used mainly in ophthalmic surgery
C-Polyglycolic acid (Dexon®)& Polyglactin 910 (Vicryl®): -
They are synthetic polymers, containing no proteins, absorbable suture materials, and have minimal tissue reaction when compared with catgut. They handle like silk and do not swell when they are wet. They drag through tissues and cut soft organs, so they are coated with absorbable lubricant to make them smoother, however, dragging can be considered as advantage when continuous suture patterns are used, as the suture material will not be slide out of the tissue. Polyglycolic acid (Dexon®) is absorbed after 40-60 days while and Polyglactin 910 (Vicryl®) is absorbed after 90 days.
D-Polylactic acid: -
It is a mono or multifilament, synthetic polymer, absorbable suture material (over 1 year)
2-Non-Absorbable Suture Materials
A-Silk: -
It is a protein filament produced by silkworm, braided, dyed, and coated with wax or silicone. It is used mainly for suturing of the skin, but it can’t be used in infected wound because of its capillarity action. Its absorption is so slaw and when used internally it may last years to disappear. A synthetic form of silk was manufactured like Mersilk®.
B-Cotton: -
Advantages: -
Lower possibility of laceration so it is used for treatment of vaginal or uterine prolapse (vaginal tape)
Disadvantages: -
It is a plant origin filament that has a higher tissue reaction and higher possibility of infection than silk
C-Nylon (Dermalon®, Ethilon®& Nurolon®): -
It is a synthetic, inert, polymer that has poor knot security. Monofilament (Dermalon® & Ethilon®) is preferred than multifilament when infection of the wound is expected although the multifilament braided nylon (Nurolon®) has some degree of roughness, better knot retention, and better handling properties.
D-Polypropylene (Prolene®) and Polyethylene: -
They are polyolefins that are usually represented in monofilament form. They have greater knot security and better handling than nylon. They are preferred than braided synthetic materials in infected wounds and can be absorbed over two years
E-Polymerized caprolactam (Supramid ®& Vetafil®): -
It is a synthetic multi-filamentous suture material made from materials related to nylon and coated to minimized capillarity, so it can be used for suturing of skin but it has poor knot security compared with silk. Like all multi-filamentous suture materials, it shouldn’t be used in infected wounds.
F-Polyesters: -
It is multi-filamentous polyester that consists of Dacron, which may be plain or uncoated (Mersilene® & Dacron®), Teflon-coated Dacron (Polydek®) or polybutylate-coated Dacron (Ethibond®), or Teflon-impregnated Dacron (Tevdek® & Ethiflex®).
The uncoated form has more tissue drag, more capillarity action, and higher knot-holding ability than coated or impregnated forms. It must not be used in infected wound.
G-Stainless steel: -
It is a non-reactive, monofilament or multifilament of iron alloy (iron-nickel-chromium), difficult to be handled because it kinks, and it has good knot security but the knot tends to be bulky.
It can be re-sterilized but it has great tendency for cutting the tissues or the gloves.
Considerations in Choosing Suture Materials
I-PHYSICAL PROPERTIES
1-Durability
Durability of the suture in the wound is affected by many factors like;
A-The diameter of the filament: -
The smaller the diameter of the filament, the faster the absorption and the lower the durability
B-Exposure to gastric enzymes: -
Exposure to gastric juice increases absorption rate and decreases durability.
C-Infection: -
Presence of infection increases the rate of absorption and decreases durability, as the body will get rid of the suture materials rapidly.
D-Blood supply of the wound: -
The higher the blood supply the greater the rate of absorption and the lower the durability, as the body will get rid of the suture materials rapidly.
E-Rate of healing & Tension of the suture line: -
The wounds with high healing rate and low suture line tension need less durable suture materials while those with slow healing rate and high suture line tension, need more durable suture materials.
2-Handling ability and knot security
Good suture material should has good handling ability, minimal capillarity, and good knot security, unfortunately, there is no suture material yet has all phenomena.
3-Sterilization
Most of suture materials are represented already sterile.
Ethylene oxide gas: -
It is a suitable method of sterilization of all suture materials.
Autoclaving: -
It is a suitable method of sterilization of most suture materials (except for catgut), but multiple autoclaving for more than three times reduces the strength of the suture material.
Gamma irradiation: -
Gamma irradiation adversely affects polyglycolic acid and polypropylene.
4-Biological Properties
Tissue reaction ensues as a result of;
1-Traumatization of the tissue by the needle, so atraumatic needle is preferred
2-Dragging of the suture material, so monofilament suture materials are preferred than multifilament
3-Chemical structure of the suture material, as most of synthetic absorbable materials hydrolyzed into chemical components that adversely affect multiplication of bacteria controversial to catgut, which is a protein that is suitable for bacterial growth.
4-Physical structure of the filament, as monofilament suture materials are preferred than multifilament materials as the former has lower chance of keeping microorganism inside it than the later
III-SUTURE PATTERNS
1-Basic Suture Patterns
A-Simple interrupted suture
Technique: -
It is a simple pattern by which the needle is inserted perpendicular at a right angle at one side of the wound (considerable distance far from the edge according to the species), passes through the wound, and exits at the same distance from other wound edge at the other side of the wound, then after the two free ends knotted, accordingly this pattern opposes the skin. This pattern is used in tissues that will not be subjected to a lot of tension.
Advantages: -
1-Simplicity
2-Opposition of the skin
3-Parallel to the blood supply of the wound and not retard healing
4-When one knot untied; the other knots maintain the strength of the suture line
Disadvantages: -
1-Time consuming because of the high number of knots
2-Consuming of large amount of silk material
3-Not suitable for areas subjected to tension
B-Simple continuous suture
Technique: -
It is the same as simple interrupted but it has only two knots, one at the beginning and the other at the end of the wound. This pattern is used for tissues that will not be subjected to a lot of tension.
Advantages: -
1-Simplicity
2-Opposition of the skin
3-It is performed faster than simple interrupted pattern
4-Consumption of lesser amount of silk
5-It is parallel to the blood supply so it will not cause retardation of healing
Disadvantage: -
1-When one stitch is untied the strength of the suture line can’t be maintained
2-Not suitable for areas subjected to tension
C-Continuous lockstitch (Ford interlocking suture)
Technique: -
It is a modification of continuous suture pattern. After the needle is inserted perpendicular on the wound and exits from the other side, it is drawn through the performed loop and tightened.
Advantages: -
1-Simplicity
2-Opposition of the skin
3-Consumption of lesser amount of silk and lesser time than simple interrupted
4-Relative maintenance of the suture line strength when one stitch is untied
5-It is parallel to the blood supply so it will not cause retardation of healing
Disadvantage: -
1-It is not as simple as the previously mentioned patterns
2-Time consuming than simple continuous pattern
3-Not suitable for areas subjected to tension
D-Horizontal mattress suture
Techniques: -
This pattern can be performed either in interrupted or continuous manners. With respect to the interrupted pattern, the needle passes through one side of the wound at point number one and exits from the other side at point number two, in the same manner as simple interrupted pattern, leaving considerable length of tissue on both sides (according to species), then at a considerable distance lower to the exit point, the needle is reinserted at point three and passes to the 1st side again to exit through point number four (at lower level than entrance point one), thus two pieces of the silk can be seen parallel to the incision. The needle should be inserted with acute angle through the skin to prevent eversion of the skin. Finally the two free ends of silk are knotted. The four points of entrance and exit form rectangle.
Regarding continuous pattern, only one knot is created at the beginning of the wound by simple interrupted stitch then the same mentioned technique is performed from one side to the other in zigzag manner with creation of another knot at the end of the wound.
Advantages: -
1-It can be used in areas where much tension is placed on the skin
2-Interrupted manner has advantages of interrupted pattern in relation to continuous patter, i.e. cutting of one stitch will not affect the other stitches etc, and continuous pattern has advantages of continuous pattern at lesser time and suture materials consumption etc
Disadvantages: -
1-The main disadvantage of that pattern is that it interferes with blood supply to the skin and interferes with healing as the suture material is perpendicular to the blood supply
2-Other disadvantages are the same general disadvantages of interrupted and continuous patterns
E-Vertical mattress suture
Technique: -
In this type of suture pattern, the needle is inserted at point number one at considerable distance from the edge of the wound (according to the species) and passes through the wound to exit at point number two at the same distance from the wound edge but on the other side of the wound.
Then the needle is reinserted at the same level at point number three that lies medial to point number two (midway between the wound edge and point number two), passes through the wound and exits at point number four medial to point number one and midway between point number one and wound edge.
Finally the two free ends of the suture material are knotted to form the stitch with two suture material lines presented perpendicular on the suture line, one on each side of the wound, at the same time the four points of entrance and exit presented at the same level. This type of suture can be used in areas where much tension is placed on the skin.
Advantages: -
1-The main advantage of that pattern than horizontal mattress pattern is that it doesn’t interfere with blood supply of the skin like horizontal type as the stitch is parallel to blood supply
2-It has the same general advantages of interrupted pattern
Disadvantages: -
1-It has the same general disadvantages of interrupted patter as consumption of much suture material and more time.
2-It causes much more eversion of the wound lips
F-Cruciate suture (Cross mattress)
Technique: -
In this type of suture, the needle is inserted at point number one at one side of the wound at considerable distance from the wound edge, passes through the wound to exit through point number two in the same manner as simple interrupted.
Then the needle is inserted at point number three at the same side of point number one and at lower level, passes through the wound and exits from point number four at the other side of the wound and at lower level than point number two but at the same level of point three.
Finally the two free ends of the suture materials are knotted. The four points of entrance and exit create rectangle and two lines of suture materials can be seen on the surface of the wound. These two lines make X or cross over the two lips of the wound and prevent eversion.
Advantages: -
1-The main advantage of that pattern than other mattress patterns is that it doesn’t interfere with blood supply nor it causes much eversion
2-It has the same general advantages of interrupted pattern
Disadvantages: -
It has the same general disadvantages of interrupted patter as consumption of much suture material and more time
G-Near-far-far-near suture
Technique: -
This type is a mixture of cross mattress and vertical mattress sutures. The needle is inserted at point number one at considerable distance from the wound edge, passes through the wound and exits at point number two at the other side of the wound but at higher level and much more far from the wound edge.
Then the needle is inserted at point number three at the same level of point number two and far from the wound edge with a distance similar to that of point number two, passes through the wound and exit at point number four at the other side of the wound, at the same level of point number one and far from the wound edge with a distance equal to that between point number one and wound edge. Finally the two free ends of the suture materials are knotted and the four points of entrance and exit creates trapezoidal shape with two unequal suture material lines that are perpendicular at the wound and parallel to each other, can be seen on the surface of the wound.
Advantages: -
1-The main advantage of that technique is that it mainly used for linea alba of horse as it is a good tension suture
2-It has the general advantages of interrupted pattern
3-It doesn't interfere with blood supply of the wound
Disadvantages: -
It has the same general disadvantages of interrupted pattern as time and suture materials consuming pattern.
H-Subcuticular suture
Technique: -
This type of suture is used to avoid the small scars produced around suture holes in other patterns. The needle is inserted into the subcutaneous tissue in the apex of the wound and passes to the other side and a knots is tied subcutaneously, then the suture is advanced like continuous horizontal mattress, but the needle is inserted in one side and exits at lower level in the same side, then it is advanced to the other side and inserted then drawn at lower level till the end of the wound. At the end of the wound the suture material is knotted subcuticular and no suture materials can be seen after suturing of the wound as the knots are subcutaneous.
2-Suture Patterns for Hollow Organs
These patterns are either opposing or inverting patterns and can be applied in as single or double rows. Single row patterns have high incidence of leakage, dehiscence, adhesion and peritonitis, while double row patterns associated with high incidence of stenosis. Whither single row or double row is the best, it stills questionable.
A-Lambert suture
Technique: -
This pattern can be used in an interrupted or continuous manner. The needle passes through the serosa, muscularis and submucosa but it doesn’t involve the mucosa.
The needle is inserted at point number one in a perpendicular manner on the wound at one side of the wound and passes the mentioned layers then it is exit at point number two that is nearer to the wound edge and at the same level of point number one and at the same side.
Then after the needle is inserted at point number three at the same level with the other two points and with a distance from the wound edge similar to that between point number two and the wound, passes the mentioned layers and exit at point number four at the same level of the other three points and far from the wound lips with same distance between point number one and the wound.
The four points exist at the same level, and after knotting the stitch, only one line of the suture material can be seen perpendicular on the wound.
Regarding the continuous manner, only two knots are created at the beginning and at the end of the wound and the only parts that can be seen after completing the pattern, are oblique and parallel lines that are perpendicular on the wound edge.
Advantages: -
1-It is the simplest pattern for the internal organs
2-It is relatively rapidly performed
3-It inverts lips of the wound, and never involves the mucosa so the possibility of contamination is low
4-The interrupted manner has the same general advantages of interrupted manner and the continuous manner has the same general advantages of continuous manner.
Disadvantages: -
1-It produces slight stenosis of the bowel
2-Interrupted Lambert has the same general disadvantages of interrupted manner and continuous Lambert has the same general disadvantages of continuous manner
3-It cause retardation of healing when it is applied perpendicular on blood supply
B-Halsted suture (interrupted Quilt)
Technique: -
It is a modification of Lambert pattern that has 8 points of entrance and exit divided on two lines (four points for each line) and can be performed either in interrupted or continuous manners. The needle passes through the serosa, muscularis and submucosa but it doesn’t involve the mucosa. The needle is inserted at point number one in a perpendicular manner on the wound at one side of the wound and passes the mentioned layers then it is exit at point number two that is nearer to the wound edge and at the same level of point number one and at the same side.
Then after the needle is inserted at point number three at the same level with the other two points and with a distance from the wound edge similar to that between point number two and the wound, passes the mentioned layers and exit at point number four at the same level of the other three points and far from the wound lips with same distance between point number one and the wound. Then the needle inserted at point number five at a level lower to that of point number four and advanced to exit through the point number six at one side of the wound then advanced to point number seven at the 1st side of the wound to exit through point number 8. The two free ends at point number one and number 8 are knotted so that only two lines of suture material can be seen parallel to the wound (one on each side).
Advantages: -
1-It inverts lips of the wound, and never involves the mucosa so the possibility of contamination is low
2-The interrupted manner has the same general advantages of interrupted manner and the continuous manner has the same general advantages of continuous manner
Disadvantages: -
1-It produces slight stenosis of the bowel
2-Interrupted type has the same general disadvantages of interrupted manner and continuous type has the same general disadvantages of continuous manner
3-It cause retardation of healing as it will be always perpendicular on blood supply
C-Interrupting inverting mattress suture
Technique: -
This pattern is similar to the horizontal mattress suture pattern but the bites of the stitch are parallel to the edges to the wound. The needle is inserted at point number one at one side of the wound at considerable distance from the wound edges and advanced parallel to the wound to exit at the same side of the wound but at lower level.
Then the needle advanced to the other side and inserted at point number three at the same level of point number two and advanced parallel to wound to exit from point number four.
The four points of entrance and exit form rectangle, and after knotting the two free ends at point number one and four, only two lines of suture material can be seen perpendicular on the wound, parallel to each other’s and of the same length.
The technique should be performed in interrupted manner and it causes inversion of the wound edges. The mucosa may be or not involved during suturing.
Advantages: -
1-It inverts lips of the wound, that lowers the possibility of contamination and if doesn't involve the mucosa, the possibility of contamination is maintained at minimal level
2-It has the same general advantages of interrupted manner
Disadvantages: -
1-It produces slight stenosis of the bowel
2-It has the same general disadvantages of interrupted manner
3-It causes retardation of healing (it is perpendicular on blood supply)
D-Cushing suture
Technique: -
It resembles inverting mattress suture but it is performed in continuous manner, and the mucosa is not involved.
Following creation of the knot at the beginning of the wound, the needle is inserted at one side of the wound at point number one and advanced parallel to the wound without penetrating the mucosa then it exits from point number two at the same side of the wound.
Then after the needle is advanced to the other side of the wound and inserted at point number three at the same level of point number two, and advanced without penetrating mucosa to exit through point number four that has level lower than that of point number three.
The final shape of the pattern shows lines of the suture material that parallel each other and perpendicular on the wound.
Advantages: -
1-It inverts lips of the wound and doesn't involve the mucosa that lowers the possibility of contamination
2-It has the same general advantages of continuous manner
Disadvantages: -
1-It produces slight stenosis of the bowel
2-It has the same general disadvantages of continuous manner
3-It cause retardation of healing as it will be always perpendicular on blood supply
E-Connell suture
Technique: -
It resembles cushing suture pattern, but the needle passes all intestinal layers, so the possibility of contamination is higher.
Advantages: -
1-It inverts lips of the wound, that lowers the possibility of contamination but it involves the mucosa, the increases possibility of contamination
2-It has the same general advantages of continuous manner
Disadvantages: -
1-It produces slight stenosis of the bowel
2-It has the same general disadvantages of continuous manner
3-It cause retardation of healing as it will be always perpendicular on blood supply
4-It has higher possibility of contamination when compared with techniques that don't involve the mucosa
F-Schemieden’s suture
Technique: -
It is an inverting suture pattern that doesn’t involve the mucosa. Stitches are brought through from inside the gut into the muscularis and drawn from the serosa
Advantages: -
It has the same general advantages of continuous pattern (rapid and consumes lesser amount of suture materials)
Disadvantages: -
1-It has higher probability of infection as the mucosa is involved and the two serosal surfaces are not permitted to come in contact as they are separated by the suture material
2-It has the same general disadvantages of continuous pattern
G-Simple interrupted suture
Technique: -
It involves the mucosa and can be performed in two manners, either simple interrupted that doesn’t interfere with circulation, or crushing manner that interferes with blood supply.
Advantages: -
It has the same general advantages of interrupted pattern
Disadvantages: -
It has the same general disadvantages of interrupted pattern
H-Gambee suture
Technique: -
It is an interrupted pattern in which the needle is inserted in a perpendicular manner into the serosa of one side of the wound at considerable distance from the wound edge, exits from the mucosa and reinserted through the mucosa to exit from the submucosa. Then it passes to the submucosa of the other side, exits from the mucosa, reinserted through the mucosa to exit through the serosa
Advantages: -
1-It has the same general advantages of interrupted pattern
Disadvantages: -
1-Less simple than other technique
2-It has the same general disadvantages of interrupted pattern
I-Parker-Kerr oversew
Technique: -
It is a mixture of cushing over which another Lambert pattern is performed. A hemostatic forceps is applied perpendicular on the hollow organ, and then the organ is severed
The 1st layer of cushing is applied after which the forceps is removed and a Lambert pattern is applied
Advantages: -
1-It has the same general advantages of continuous pattern
2-It has lower possibility of contamination
Disadvantages: -
1-It has the same general disadvantages of continuous pattern
2-It is associated with higher possibility of retardation of healing
J-Purse string suture
Technique: -
This pattern can be used to close small holes that evacuate gas from the bowel or to keep cannulae in situ, but it is mostly used with anus to retain rectum during rectal prolapse.
The needle is inserted parallel to the anal opening, 1.5 cm far, and advances subcutaneously for 1.5 cm then drawn, then reinserted with the direction of watch 360 degree, then the two ends of the suture material are tied in special manner that facilitates untying and retying for frequent evacuation of rectal contents.
3-Suture Patterns for Severed Tendons
A-Bunnell suture
Technique: -
Most of suture materials are kept inside the tendon to maintain the gliding function of the outer surface of the tendon and the suture material presented parallel to the tendon.
Double round needle suture materials are used in this pattern. Starting at the right side, one needle is inserted at considerable distance from the edge of the severed tendon at right angle, and then the needle is reinserted 0.2 cm far to this site in diagonal or oblique direction toward the other surface of the tendon and exits at a point about 40% of the remaining distance. The same needle is reinserted 0.2 cm far and diagonally to exit at about 80% of the whole distance to the original surface.
The other needle is advanced in the same manner, so finally an eight figure is formed inside one end of the tendon. In the other side of the severed tendon, the two needles are advanced from the end of the tendon and in the same mentioned manner.
All we can see are seven 0.2 cm long suture materials parallel to the tendon, two longer lines (one on each surface of the tendonn), and a knot. They all constitute 10 points.
B-Locking-loop tendon suture
Technique: -
The needle is inserted through the cut surface of the tendon and advanced in the tendon to a considerable distance then drawn from one surface, at a point 0.3 cm lower and lateral to the point of puling of the needle, the needle is reinserted and passes perpendicular on the tendon, exits through the same surface, reinserted 0.3 cm higher and medial to the point of drawing, and then advanced parallel to the tendon and drawn from the cut edge at the same level of the 1st bite. The needle is advanced in the other side of the severed tendon in the same manner and the knot is made in the cut surface of the tendon.