Dear Marco, forum readers and fellow HT doctors,
I have read the debate about use of needles v/s the blades.
Let me state that we used custom cut blades till approx. 6 years ago and shifted to sharp needles thereafter, as I felt needle based slit creation to be better.
As other doctors know, besides me, both the needles as well as blades make slits.
Hairsite has a video presented by Dr. Woods, where the making of a slit is clearly demonstrated using a hypodermic needle.
I have no problem if some clinics prefer the use of blades instead of needles.
Once one realizes that its the slit creation v/s hole creation that matters, then needles and blades lose much relevance.
Needle created lateral slits offer a small advantage, in my view. The needle too has a cutting edge. Akin to the blade. But it also has a thicker calibre as we go from tip upwards. It has a sharp cutting edge at the tip (like a blade) but turns into a round cylinder as one goes up.
This thick 3 dimensional calibre of the cylinder aids in blunt dissection while creating the recipient slits. The front edge of the needle creates a slit which is widened by the cylindrical widening of the needle.
Therefore, for the same size of the slit, a %age of the circumfrential dissection is created by blunt dissection when using the needle.
All surgeons realize the benefits of blunt dissection v/s sharp cutting.
This, in my experience, reduces the inflammatory load on the recipient area. This is best observed by the reduction in the incidence of massive oedema post HT.
Since we started using needles to create the recipient slits, less than 1% of our patients experienced periorbital oedema.
Of course, other factors too play a part in reducing this edema, but, I think, the use of needle contributing to the reduction in the actual sharp cutting of the tissues compared to blades, helps too.
Most experienced HT surgeons know that the scalp thickness as well as the hair direction keeps changing from place to place on the scalp.
The depth control and the direction control is better when using a needle than a blade.
I do not say that a doctor can not make the same controlled incisions with a blade (compared to a needle). Some can use the needle better, others may use the blades.
Correctly used, both can do an equally good job.
A more important issue is following the policy of making all slits at one go v/s going for the stick and place method. Depth control, angulation control etc. are more of a problem in the stick and place method. But that is another topic.
Also, lateral slits and sagittal slits are not mutually exclusive.
In certain areas, depending on the hair directions, lateral slits lie in the sagittal plane.