Dear Dr. Cole, with donor area stretch back following a strip procedure, doesn’t this make a strip a better procedure than FUE. Or should we combine FUE and strip surgery to get better coverage?
In 2002 I did a donor area stretch back study, which I presented in Chicago. I was working with MHR at the time and left soon thereafter. I never got my 6 month data on most of the patients, but I had 3 month data.
Twenty-one patients were enrolled in the study. Sorry, but I never wrote the data up.
I placed two tattoo marks 0.5 cm above the proposed strip of 1.2 cm width. I also placed two tattoo dots 2.0 cm above each proposed strip line. I then measured the distance between the tattoo marks post surgery and at 3 months. I did not get enough 6 month data to evaluate the results.
The mean distance pre-op between the 0.5 cm dots was 2.11 cm and the mean distance between the 2 cm dots was 5.08 cm pre-op. At 3 months the distance between the 0.5 cm dots was 1.27 cm and the distance between the 2 cm dots was 4.57 cm.
If you look at stretch back alone, the distance between the 0.5 cm dots was 1.27/2.11 or 60% and the stretch back between the 2.0 cm dots was 4.57/5.08 or 90%.
Stretch back is not what you want to look at though. What you want to look at is surface area because density is a measure of Follicular units/surface area. Stretch back implies the surface area returns toward a pre-operative state, but it does not fully evaluate density.
If you look at the surface area of 1 sq cm 0.5 cm above and below the 1.2 cm strip, pre-operatively, it was 0.91 sq cm. If you look at the surface area 2.0 cm above and below the 1.2 cm strip pre-operatively it was 2.97 sq cm. After 3 months the 0.5 cm surface area totalled 1.27 sq cm and the 2.0 cm surface area totaled 3.3 sq cm.
If you look at the change in surface area, the change was 0.36/1.27 or 40% increase at the 0.5 cm marks and it was 0.33/2.97 or 11% increase at the 2.0 cm marks. The surface area increase at both marks, but more at the 0.5 cm marks. Density is a function of FU/sq cm. Since FU(s) do not change, density has to decrease necessarily at both locations.
In fact this is what I observed. Density decreased from 80/sq cm at the 0.5 cm marks and from 80 to 72 at the 2.0 cm marks. This is what you”d expect since surface area increase the most next to the strip scar.
Note that this study was a single strip scar of only 1.2 cm width taken with a two blade Arnold knife to insure that the width was 1.2 cm wide. You would expect an even more dramatic increase in surface area with a wider strip or with multiple strips.
This is also what I see with FUE hair Transplantation. Follicular density is lowest adjacent to the strip scar. It continues to lower as you move away from it. With more and more strips, the density decreases even more. So, combinations become harder and harder to obtain adequate graft numbers. Again, you need hair to cover strip scars and strip scars become wider with multiple strips. Density decreases with each strip as surface area continues to increase eight multiple strips while the total number of FU(s) remains the same. It”s a progressively diminishing return on your efforts because the overall follicular density continues to decline. At some point, it becomes hard to cover a strip scar even when harvesting fewer grafts.
Both procedures reduce the Follicular Density (FD). The trade off in one is that you have a thinner donor area with FUE, while with the strip you have a thinner donor area and a strip scar that needs hair to cover it. This is why I do not like combination procedures.