Ch 16 - Materials and Closure Flashcards
List some reported used of barbed suture
- Gastropexy
- Gastrotomy
- Enterotomy
- Intestinal anastomosis
- SDFT and gastrocnemius tendon repair
In GIT surgery, results in faster repair with equivalent or better bursting strength and leakage
However, significantly underperforms smooth knotted suture in tendon repair for ultimate tensile strength and gap formation
What are the 2 major methods of suture absorption?
- Enzymatic (predominates in natural materials)
- Hydrolytic (Predominates in synthetic sutures)
List the disadvantages of Catgut
- Relatively weak
- Not uniform
- High tissue reaction
- Absorption is extremely variable and unpredictable
- very rapid absorption in gastric or intestinal surgery
What species of worms produce silk
Bombyx mori
Anaphe pernyi
What are the disadvantages of Nylon Leader Line
It was not designed as an implantable biomaterial. It will elongate under constant loads and its physical properties are significantly influenced by steam sterilisation
Steam sterilisation resulted in a 204x increase in elongation
What is the strongest form of suture?
Polyester composite sutures eg FiberWire (multifilament UHMW polyethylene core surrounded by braided polyester and polyethylene exterior)
What is meant by the warp, weft, and bias of woven mesh
Tend to be more elastic and fluid in the bias direction
What is meant by the course and wale of a knitted mesh?
They are anisotropic with more elongation along the course than the wale
What is meant by the pore size and porosity of mesh materials? How does this effect its properties?
- The ratio of material to air
- Polypropylene mesh - pore size 0.6-0.9mm with porpsity 28-32%
- ePTFE pore size 20-25nm
Very small pore size will prevent capillary ingrowth causing encapsulation rather than incorporation
What biologic materials have been used as mesh?
- Porcine SI submucosa
- Bovine pericardium
- Acellular dermal matrix
- Canine fascia lata
3months after implantation, porcine SIS is histologically non apparent and has been replaced
Fascia lata consistently has shown the best biological properties followed by polypropylene
What are the recommendations for implantation of mesh?
- Trimming with electrosurgery may seal edges and prevent fraying
- Create a hem
- Horizontal mattress sutures will engage more mesh
- If under tension, should overlay 1cm of tissue
- Little or no tension, 0.6cm overlap
What are the dimensions of regular and wide skin staples? Are skin staples appositional, inverting or everting?
Slightly everting
What are the principles of vascular clip application?
- Vessel is skeletonised prior to application
- Diameter of the vessel should be no more than 2/3 and no less than 1/3 the length of the clip
- Clip applied several mm from cut edge
- Arteries and veins clipped seperately
What sized staples are in the coloured cartridges of TA devices?
Green - 4.8mm to 2.0mm
Blue - 3.5mm to 1.5mm
White - 2.5mm to 1mm
What can linear staplers be used for?
- Pulmonary Sx
- Cardiac Sx
- GI
- hepatobiliary
- reproductive