The two major types of metal alloys used in the manufacture of surgical instruments are Stainless Steel and Titanium.
Stainless Steel is the preferred raw material for surgical instrument applications. Fully 95% of all surgical instruments are manufactured from Stainless Steel. Stainless Steel is an ideal alloy since it is a rust resistant material which may be honed and polished to an extremely sharp edge or point. In surgical applications, Stainless Steel is hardened to provide a durable edge and ensure proper jaw alignment and tip approximations. The term “stainless” is a misnomer in that Stainless Steel is subject to both water spotting and staining. The brown stain or discoloration that often occurs after steam autoclaving is a type of patina, designed to protect the Stainless Steel instrument from corrosion, much the same way that copper turns a greenish blue.
NOTE:Severe staining (dark brown), or rust spots on the instrument may indicate that you have a sterilizer problem and you should contact a service technician for cleaning or adjustment.
Titanium is an alloy which is employed in the manufacture of some surgical instruments. Titanium alloys are much stronger, lighter and more resistant to corrosion than Stainless Steel. Titanium does not contain carbon and it will not magnetize. Due to its metallurgical structure, Titanium is difficult to sharpen and hone to a fine edge or point, limiting its uses in surgical instrument applications
Proper Use:
Proper utilization of a surgical instrument will significantly increase the instruments’ useful life. Avoid instrument abuse by using the instrument only for their specific surgical purpose.
These common mistakes should be avoided:
Using microsurgical scissors, forceps, or needle holder as a cautery.
Tapping a jeweler or microsurgical forceps on a table or tray to position the instrument in your hand.
Using a needle holder as pliers.
Using a needle which is too large for the needle holder. Always match the needle to the needle holder.
Cutting tendons, cartilage, bone, or skin with delicate microscissors.
Cutting paper, plastic, gauze, or wire with scissors designed to cut tissue.
Dropping a micro-instrument on the floor, or into a tray or bucket.
Using vessel clamps as tubing clamps.
Mismatching vessel and vessel approximator sizes.
Using micro-instruments for macro surgery.
Cleaning:
All instruments should be thoroughly cleaned after each use. Never allow blood or other contaminants to dry on the instruments. In general you should follow your established institutions cleaning and sterilization practices.
Remove blood, tissue, saline, and other contaminants from the instrument by rinsing with distilled, filtered or sterile water immediately after each use. Cleaning should always be done with distilled or sterile water. The use of tap water may lead to corrosion due to the high mineral content found in some municipal water systems.
Clean instruments with a mild soap or detergent using a soft bristle brush; a common finger nail brush works well. The use of a neutral pH (7.0 to 8.5) level detergent or soap is strongly recommended. An alkaline detergent (higher than 9.0) will stain and may cause an instrument to fracture in stress areas. An acidic detergent (lower then 6.0) may cause an instrument to pit and eventually corrode. Do not use a towel or a rag to wipe the instruments, as this may damage tips such as those found on pierce type forceps. Take care to open and clean the inside of box locks. Instruments with removable parts should be disassembled whenever possible and thoroughly cleaned.
For ultrasonic cleaning, follow the manufacturer's specific instructions for proper use of the Ultrasonic Cleaner. The following general rules should be adhered to:
To protect the instruments from damage, the instruments should be immersed in the ultra sonic cleaner utilizing a mesh type tray.
For added protection, the tray may be lined with a finger-like silicone pad.
Care should be taken to ensure that the instruments do not touch one another while in the tray.
Scissors, needleholders, and forceps should be in the open position.
Cleaning time is usually five minutes. After the ultrasonic cycle, rinse instruments in distilled or sterile water removing any chemical residue from the instruments.
Allow the instruments to air dry. For expediency, a blow dryer may be used. Do not dry instruments with a towel or gauze, as this may cause tip damage.
Inspection:
Instruments should be inspected on an ongoing basis.
Needle holders should be able to hold a needle in the closed position. Visually inspect the jaw areas by holding the instrument up to a light. When closed, no light should pass through the jaws. If light shines through the jaws, the jaws are splayed and need to be repaired or replaced. Check Tungsten Carbide inserts for wear. Look for worn out or smooth serrations in the jaw area. Check box locks for stress cracks. For locking needle holders, make sure that the ratchet or spring catch is not worn out or broken.
Scissors should be checked for bent tips, burrs, or nicks in the cutting edges of the blades. Check for loose set screws which may prevent a smooth cutting action. Tungsten Carbide scissors should be checked for loose or cracked inserts.
Forceps should be examined for misaligned or bent tips. Pierce forceps and forceps with 1 X 2 teeth should be inspected for bent or missing teeth. Ring handled forceps should be opened to inspect box locks. If a box lock is loose, jaw misalignment may occur. Check for stress cracks in the pin area and at the proximal end of the serrations.
Severely damaged instruments should be taken out of service immediately. Most minor damage, such as burrs in a scissors blades and misaligned tips, may be repaired by a qualified instrument repair technician.
A simple way to lengthen an instrument’s useful life is to lubricate it. Instrument lubricant not only lubricates an instrument, it leaves a protective film on the instrument which enhances the instrument's corrosion resistance. When lubricating an instrument follow the manufacturer’s instructions carefully. Generally, the following procedures apply:
After the instruments have been thoroughly cleaned and dried, lubricate the instruments. The instruments should be in the open position for best penetration and results.
Let the instruments drip dry for a few moments prior to use or before wrapping for autoclaving.
NOTE:Prior to autoclaving or storage, instruments should be placed into a tray. Care should be taken to ensure that instruments do not touch one another, as this may lead to damage of the tips and cutting edges.
In general, you should follow your institute’s sterilization standards.
The most widely used form of sterilization is steam autoclaving, due to its short cycle time.
Flash autoclaving is also acceptable; however, flash autoclaving will greatly reduce an instruments useful life. High temperatures associated with flash autoclaving may temper (soften) an instrument and will eventually lead to breakage or corrosion.
The best method of sterilizing micro-instruments is ethylene oxide (ETO) sterilizing, ETO sterilizing is recommended because of the low temperatures and moisture levels during processing. A micro-instrument's useful life will be significantly lengthened when ETO sterilization is employed.
It is highly recommended that microsurgical instruments be stored and sterilized in a separate tray or container. Combining microsurgical instruments with macrosurgical instruments in a tray or container will lead to damage during sterilization, transportation, and use. Microsurgical instruments should be stored in a separate tray, preferably within some type of silicone cradling system as this is softer and cushions the instrument better than a Stainless Steel or metal cradling system. Tip protectors should be placed on each microsurgical instrument, further protecting the instrument from damage should any shifting occur while the instrument is in a tray or container.