Implanted Materials

Question 1

What is the definition of an implanted material?

Answer 1

Anything put in the body that remains for a prolonged period

Question 2

Name 4 uses for suture material

Answer 2

• Closing tissues
• Ligation
• Anchoring drains and tubes
• Atraumatic tissue manipulation

Question 3

What is a round-bodied needle?

Answer 3

Smaller hole in tissue, harder to pass through fascia
* Used in tissues easy to penetrate
* Blunt ended
* Used in parenchymatous organs, fat and muscle

Question 4

What is a cutting needle?

Answer 4

Cutting edge concave side
* Larger hole in tissue, easier to pass through fascia/skin

Question 5

What is a reverse cutting needle?

Answer 5

Cutting edge on convex side
* Less risk of pulling needle though tissue bite
* Smaller hole in tissues

Question 6

What is a tapercut needle?

Answer 6

• Sharp Cutting Point
• Used for fascia and pericardium

Question 7

What is the characteristic of an absorbable suture?

Answer 7

Loses most tensile strength within 90 days
* Use for tissues inaccessible after implantation
* Short duration <21 days
* Long duration >21 days
* Influenced by environment (urine . . .)

Question 8

What is the characteristic of a non-absorbable suture?

Answer 8

Does not lose tensile strength within 90 days
* 6 months (nylon) to years
* Use for slowly healing tissues, tissues requiring prolonged mechanical support Or where
easily accessible
* for removal
* Elicit tissue reaction resulting in encapsulation by fibrous tissue
* E.g.silk used for vascular surgery

Question 9

What is chromic catgut impregnated with?

Answer 9

Chromium trioxide, stronger and lasts longer

Question 10

How does catgut degrade?

Answer 10

It degrades via phagocytosis
* Unpredictable tensile strength
* marked FB reaction
* loses strength more rapidly

Question 11

What is polydioxanone, and what is it used for?

Answer 11

Sites where slow healing but not permanent suture
needed
* Abdominal wall, ruptured diaphragm, muscle/fascia
* Removed by hydrolysis

Question 12

When might you use monocryl?

Answer 12

Fast-healing structures with not a lot of forces
applied
* Subcutaneous, intradermal, mucosa
* Loses strength quickly

Question 13

When might you use vicryl?

Answer 13

Fast-healing structures with not a lot of forces
applied
* Subcutaneous, intradermal, mucosa
* Where safe knots needed – ligatures
* Where soft sutures needed (oral cavity

Question 14

When might you use nylon?

Answer 14

Skin sutures, securing tubes and drains
* Permanent sutures in the body (tendon repair, hernia repair)
* Ethilon (monofilament Nylon) and Supramid (multifilament Nylon)

Question 15

When might you use prolene?

Answer 15

skin sutures
* Permanent sutures in the body (tendon repair, hernia
repair)
* Used for vascular sutures

Question 16

How might you choose the tensile strength of a suture?

Answer 16

Suture should be as strong as the normal strength of tissue in which it is
being used
* Rate of loss of tensile strength should be parallel to the increase in wound
strength with healing
* Forces exerted on the tissue (and sutures)

Question 17

How might you choose the knot security of a suture?

Answer 17

Improves as diameter decreases
* Too small diameter less strong in larger patients
* Too large diameter = excessive tissue reaction
* Number of throws required to make a secure knot varies with material and
pattern

Question 18

When should sutures generally be removed?

Answer 18

Generally removed ~10 days
» Skin bursting strength only ~20% normal
» Minimises inflammation/infection risk
» Rarely problem as stress taken up by underlying
fascial closure
» If tension then leave in for 14-21 days
» Tension relieving sutures interspersed can be
removed in 3-5 days

Question 19

What makes up tissue glue?

Answer 19

Cyanoacrylates
* Instant water tight seal
* Will not resist tension
* Reduce infections? (limit contamination before fibrin seal)
* Do not use in deep tissues
* place over apposed wound not in between wound edges
* FB
* Sloughs in 5-10 days

Question 20

What is a sub-ureteral bypass?

Answer 20

• Treating a blocked bladder
• tube carries urine from the kidneys to the bladder

Question 21

What is an ameroid constricter used for?

Answer 21

Used to gradually close a blood vessel or shunt