Chapters 6 & 7 - Sutures And Stitches, Surgical Knot Tying Flashcards
What is a suture?
Any strand of material used to ligate blood vessels or to approximate tissues
How are sutures sized?
By diameter; states as a number of 0’s; the higher the number of 0’s, the smaller the diameter
E.g. 2-0 suture has a larger diameter than a 5-0
Which is thicker, a 3-0 suture or a 1-0
1-0 suture
What are the two most basic suture types?
Absorbable and non-absorbable
What is an absorbable suture?
Suture that is completely broken down by the body (dissolving suture)
What is a nonabsorbable suture?
Suture is not broken down (permanent suture)
What are catgut sutures made of?
Purified collagen fibers from the intestines of health cows and sheep
What are the two types of gut sutures?
Plain and chromic
What is the difference between plain and chromic gut?
Chromic gut is treated with chromium salts (chromium trioxide), which results in more collagen crosslinks, making the suture more resistant to breakdown by the body
What is a vicryl suture?
Absorbable, braided, and multifilamentous copolymer of lactide and glycoside
How long does vicryl retain its strength?
60% at 2 weeks, 8% at 4 weeks
Should you every use purple-colored Vicryl for skin closure?
No, it may cause purple tattooing
What is a PDS suture?
Absorbable, monofilament polymer of polydioxanone (absorbable fishing line)
How long does PDS maintain its tensile strength?
70-74% at 2 weeks, 50-58% at 4 weeks, 25-41% at 6 weeks
How long does it take for PDS to complete absorption?
180 days (6 months)
What is silk?
Braided protein filaments spun by the silkworm larva; known as a nonabsorbable suture
What is Prolene?
Nonabsorbable suture used for vascular anastomoses, hernias, abdominal fascial closure
What is nylon?
Nonabsorbable “fishing line”
What is monocryl?
Absorbable monofilament
What kind of suture should be used for the biliary tract or the urinary tract?
Absorbable, otherwise the suture will end up as a Indus for stone formation
What are the three types of wound healing?
- Primary closure (intention)
- Secondary intention
- Tertiary intention (Delayed Primary Closure or DPC)
What is primary intention?
When the edges of a clean wound are closed in some manner immediately (e.g. suture, Steri-Strips, staples)
What is secondary intention?
When a wound is allowed to remain open and heal by granulation, epithelization, and contraction
Used for dirty wounds, otherwise an abscess can form
What is tertiary intention?
When a wound is allowed to remain open for a time and then closed, allowing for debridement and other wound care to reduce bacterial counts prior to closure (i.e. delayed primary closure)
What is another name for tertiary intention?
DPC (delayed primary closure)
What is a taper-point needle?
Round body, leaves a round hole in tissue (spreads without cutting tissue)
Used to suture soft tissues other than skin (e.g. GI tract, muscle, nerve, peritoneum, fascia)
What is a conventional cutting needle?
Triangular body with the sharp edge toward the inner circumference; leaves a triangular hole in tissue
Used for suturing of skin
What is a simple interrupted stitch?
Each stitch is cut after the knot is complete, before starting the next stitch
What is a vertical mattress stitch?
Simple stitch is made, the needle is reversed,and a small bit is taken from each wound edge
The knot ends up on one side of the wound
What is the vertical mattress stitch also known as?
Far-far, near-near stitch; oriented perpendicular to wound
What is a vertical mattress stitch used for?
Difficult-to-approximate skin edges; everts tissue well
What is a simple running (continuous) stitch?
Stitches made in succession without knotting each stitch
What is a subcuticular stitch?
Stitch (usually running) placed just underneath the epidermis, can be either absorbable or nonabsorbable (pull-out stitch if nonabsorbable)
What is a pursestring suture?
Stitch that encircles a tube perforating a hollow viscus (e.g. gastrostomy tube), allowing a hole to be drawn tight and thus preventing leakage
What is a gastrointestinal anastomosis (GIA) device?
Stapling device that lays two rows of small staples in a hemostatic row and automatically cuts between them
What is a Lambert stitch?
It is a second layer in bowel anastomoses
What is a Connell’s stitch?
The first mucosa-to-mucosa layer in an anastomosis; basically a running U stitch
What is a suture ligature (a.k.a. “Stick tie”)?
Suture is anchored by passing it through the vessel on a needle before wrapping it around and occluding the vessel; prevents slippage of know-use on larger vessels
What is a retention suture?
Large suture (#2) that is full thickness through the entire abdominal wall except for the peritoneum; used to buttress an abdominal wound at risk for dehiscence and evisceration
What is a pop-off suture?
Suture that is not permanently swaged to the needle, allowing the surgeon to “pop off” the needle from the suture without cutting the suture
What is the basic surgical knot?
Square knot
What is the first knot that should be mastered?
Instrument knot
What is a “surgeon’s knot”?
Double-wrap throw followed by single-square knot throws
What are the guidelines for the number of minimal throws needed?
Depends on the suture material:
Silk - 3
Gut - 4
Vicryl, Devon, other braided synthetics - 4
Nylon, polyester, polypropylene, PDS, Maxon - 6
How long should the ears of the knot be cut?
Some guidelines are:
Silk vessel ties = 1 to 2 mm
Abdominal fascia closure = 5 mm
Skin sutures, drain sutures = 5 to 10 mm (makes them easier to find and remove)
When should skin sutures be removed?
As soon as the wound has healed enough to withstand expected mechanical trauma; any stitch left in more than ~10 days will leave a scar
Guidelines: Face - 3 to 5 days Extremities - 10 days Joints - 10 to 14 days Back - 14 days Abdomen - 7 days
How can strength be added to an incision during and after suture removal?
With Steri-strips
In general, in which group of patients should skin sutures be left in longer than normal?
Patients on steroids
How should the sutures be cut?
Use the tips of the scissors to avoid cutting other tissues; try to remove cut ends (less foreign material decreases infection risk)
Rest the scissor-hand on the non-scissor hand to steady
How is an instrument knot tied?
Always start with a double wrap, known as a “surgeon’s knot”, and then use a single wrap, pulling the suture in opposite directions after every “throw”
Does a student need to know a one-hand tie?
No; master the two-hand tie and instrument tie
What is the basic position for the two hand tie?
“C” position, formed by the thumb and index finger; the suture will alternate over the thumb and then the index finger for each throw
Lead with the index finger first, then the thumb
