Insuring the Integrity of Follicular Units
Let’s consider for a moment the other techniques that we think are integral to the follicular unit transplantation process. One is single strip harvesting, and the other is stereo-microscopic dissection. Without these companion techniques, the procedure may be called follicular unit transplantation, but it is a pale, inefficient imitation.
As its name implies, single strip harvesting is the method by which a single strip of hair-bearing scalp is carefully, indeed, painstakingly, excised from the donor area; the strip is then broken down into its smallest functional units, or follicular units. Before single strip harvesting came to the fore in recent years, older, infinitely more wasteful methods were employed. The first of these was the circular, punch grafts of yore, which have little to recommend them save their simplicity (they are essentially biopsy punches), and the ease with which they were directly placed into correspondingly circular holes in the recipient area. Next, ingenious surgeons devised multi-bladed scalpels; three or more (sometimes many more) blades, attached to a handle, were oriented parallel to one another, and many thin, narrow, long strips could be excised with one pass of the scalpel. These strips could then be placed flat on their sides and sliced into small mini- and micro-grafts, with little or no concern for follicular unit integrity. This, however, was not the only drawback; transection rates were generally rather high, and were even higher when more blades were used. So time was saved, but lots of valuable follicles were wasted.
What we know as single strip harvesting overcomes many of these disadvantages. Using a single blade with genuine open technique, it is possible, with experience and well training, the transection rates of several follicles is achieved. It is estimated that transection rates as high as 37% occur with the use of multi-bladed scalpels. Let’s do the math. If the patient needs 1000 grafts, then an area containing 1370 grafts would need to be removed just to account for wastage and still produce 1000 intact FU’s. If 2000 grafts were needed, 740 would need to be wasted! This is of serious import when we deal with a limited, finite amount of donor hair.
This leads us to a discussion of graft dissection. One of the reasons many surgeons have used multiple strip harvesting with multi-bladed scalpels, is that an intact, single strip presents a number of difficulties in dissection. It is too thick to place on its side or to shine light through (transilluminate) in order to visualize the individual FU’s. Therefore, thin, multiple strips lend themselves to rapid, albeit inefficient, slicing of grafts. We feel, however, that the degree of wastage is unacceptably high, both during the strip harvest, and during graft preparation.