There are numerous instruments for creating recipient sites. These include custom made blades, hollow core needles, solid core needles, sapphire blades, and SP 89 – 91 blades, as well as other less commonly used items.
Custom Made Blades:
These consist of razor blades cut to a specific size. We first began using these in 1991 as an alternative to the use of scalpel blades for micro and mini grafts. Of the ensuing years, the number of recipient sites increased from under 100 in an average case to well over 1000. Eventually, the number of recipient sites exceeded several thousand sites. Custom made blades allow the physician to prepare specific size blades for grafts that contain a specific number of hair. For instance, the physician might use a 0.7 mm to 0.9 mm blade for single hair grafts. He might use a 1.0 to 1.1 mm blade for two hair grafts. He might use a 1.2 to 1.4 mm blade for grafts containing more than 2 hairs. Each physician has his own idea of the ideal blade size for his grafts that contain a specific number of hair. In general, it takes more skill by the surgery staff to insert grafts of a specific size into the smallest recipient sites.
There are two types of blades that are used to make recipient sites. One is the double edge blade. This is much sharper. The diameter of the blade is only 0.1 mm. This blade will stay sharp for several thousand recipient sites unless you damage the cutting edge. Occasionally, these blades will dull more easily when cutting into scar tissue or in when they hit the skin in thin scalps such as those you might encounter from a scalp reduction. If they hit something hard such as a surgical tray or counter, they will dull quickly. They are not good for stick and place as they tend to dull easily when used for stick and place.
The second type of blade is a single edge. This blade is 0.25 mm in diameter and is stronger. It also is not as sharp as the thinner walled double edge blade. These blades are good for smaller recipient sites such as the 0.7 mm site because the added wall diameter adds additional strength to the blade.
Some physicians prefer the thinner sharper double edge blade such as the author. Others such as Dr. Wong prefer the thicker walled single edge blade.
There are two types of needles. One is the hollow hypodermic needle. The second is the solid core needle. The solid core needle will stay sharper longer than the hollow hypodermic needles that are made of a softer metal. Smaller hypodermic needles will stay sharper longer than the larger gauge needles. The smaller needles include anything a 20 gauge needle and 21 gauge needle. The larger 18 gauge and 19 gauge needles will generally stay sharp for about the first 80 to 100 grafts. The advantage of the solid core needle is that it will stay sharp for several thousand-graft sites provided that you do not bend the tip of the needle by allowing it to hit the skull or to hit a hard surface. “Dinging the tip” will create a bur on the needle and cause it to dull immediately. Thus, if you want to get the maximum benefit from solid core needles, you should do your best to protect the tip.
Hollow core needles also in theory will bury some epidermis into the lower layers of the skin. Some feel this leads to cyst formation. The author did not find this problem to be an issue with hollow core needles.
These are quite common and are used by many physicians. They dilate and cut the sites. The diameter of the blade is about 0.5 mm. These do not fit into the Counting Incision Device at this time, but we are working on an adaptor for that will facilitate their use.
Recipient site size
Currently, there is no data to support the advantage of smaller recipient sites. One can anticipate a higher density with smaller recipient sites, but higher densities can also affect the yield from your grafts. Slightly larger sites allow for less trauma when placing the grafts by your technicians. Furthermore a slight larger site will result in less pressure on the grafts from the walls of the recipient site. Forces in a recipient site on a graft come from two sources. One is the force of the walls of the recipient site on the graft. The second is from the graft onto the recipient site. This compressive force, if great enough, can affect circulation to the graft in a negative manner. For this reason, the author prefers a more comfortable site for the grafts.
One should also recognize that grafts have a tendency to pop in some patients. Patients with hard skin and little elasticity have little give in the skin. There is also less compression due to elastic recoil on the graft once it is placed into the recipient site. This can lead to graft popping.
Graft popping can often be overcome by trying a variety of instruments to make a recipient site. One might start with custom blades of a specific size and find there is popping. One can then change to a larger or smaller blade. Alternatively, the author often finds that changing to a needle to make recipient sites is of benefit. With very large grafts and a rock hair, inelastic skin, the author has even found that 16 gauge needle sites were the only way to minimize popping.
The authors experience in patients with African American decent resulted in better results from using SP 89 to 91 sites. The SP 89-91 blades are quite thick in diameter and seem to dilate the incision as well as make an incision. Skin in African American patients is often much harder with less elasticity. Not only did the SP blades work well in the Negro patient, they also resulted in better growth in the author’s hands.
Incision Site Depth
It is important to control the depth of your incision for a variety of reasons. Minimizing the depth will reduce bleeding. Reducing the depth causes less tissue destruction and a lower probability of tissue necrosis. Reducing the depth can minimize the risk of burying grafts that can lead to pitting. Reducing the depth protects the tip of the cutting edge of the instrument you use to make sites by eliminating the risk of hitting the skull. The Counting Incision Device (CID) has a depth control mechanism.
In general, Caucasian grafts are between 4 and 5 mm long. Usually you can make your recipient sites 4 mm deep. With longer follicles, you might want to increase the depth of your incision sites up to 5 mm. Many Asian patients have follicles that are even deeper. In these patients, the follicles may be longer than 5 mm. In such instances, you may find that a depth of 5 to 5.2 mm is required.
The Counting Incision Device (CID) is designed to hold the custom blade or needles. It does not currently hold the sapphire blade or the SP 89-91 blades.