Maximizing Graft Survival in Follicular Unit Excision: The Implantation Phase

57 Maximizing Graft Survival in Follicular Unit Excision: The Implantation Phase

Bradley R. Wolf and Robert H. True

Summary

All of the measures that are useful to optimize the survival of follicular unit transaction (FUT) grafts are also necessary for follicular unit excision (FUE) grafts. However, FUE grafts often have characteristics that make them more challenging to place than grafts produced by FUT. FUE grafts that contain widely splayed and denuded follicles are the most difficult to place without damage. Implanters and graft introducers (like the Koray Erdogan Embedding Placer [KEEP]) are felt to be a safer way to place FUE grafts because the fragile naked bulbs do not need to be touched and are protected during placement. FUE grafts can be graded according to the Graft Placement Index (GPI) in order to tailor placement for each type of graft and measure and predict survival.

Keywords: graft placement graft implantation follicle splay follicle skeletonization forceps implantation graft implanters repetitive placement trauma

Key Points

•The success of follicular unit excision (FUE) is greatly influenced by the graft placement technique.

•Implanters are the best placement technique for FUE grafts with splay and bare follicles.

•The forceps placement technique must be modified for FUE grafts.

57.1 Introduction

Follicular unit excision (FUE) surgery is comprised of two steps, graft excision and graft implantation. The first step, graft excision consists of two phases (graft incision and graft extraction), which are discussed in Chapter 56. The second step, graft implantation, is one of the most important phases of hair restoration surgery. Trauma during this phase is a common cause of poor growth. Dr. Bradley R. Wolf discusses graft implantation in detail in Chapter 45 of this textbook as well as in his excellent article in Hair Transplant Forum International.¹

It is widely recognized that graft placement during FUE surgery is more difficult, and presents unique challenges, not present with strip-FUT. Whereas all the technical considerations that apply to graft placement with strip surgery apply to FUE, there are some extra challenges that present when placing grafts with FUE.

In the past, comparison studies on survival have shown yield in FUE to be less than FUT.² The cause of this lower yield with FUE was felt to be due to multiple factors intrinsic to the FUE process. One factor was attributed to injury caused by excessive force during the graft extraction (pulling) phase that crushes or tears follicles. Another factor is that FUE grafts have characteristics that make them difficult to place without injury. These include skeletonized or denuded grafts, exaggeration of follicle splay, the absence of “safe” tissue to grasp with forceps, and greater vulnerability to desiccation.

A few more recent studies, using some of the advancements in FUE technology, have suggested that yield with FUE can be equal to (or even greater than) FUT when these characteristics are addressed and mitigated.²^,³ Special techniques, care, and attention are required in FUE graft handling and placing to get maximum yield.

57.2 Preserving Graft Quality During the Excision Phase

The focus of this chapter is on graft preservation during the implantation phase, but it is worthwhile to review important aspects of the excision phase that have a direct negative effect on survival during the implantation phase.

57.2.1 Preventing Skeletonized Grafts

Skeletonized grafts are stripped of perifollicular tissue in the lower portion of the graft (Fig. 57.1). In the extreme, only the upper third of the graft will have perifollicular tissue. Studies by Beehner⁵ support the observation that “chubby” grafts survive better than “skinny” grafts that have no cutaneous tissue around the follicles. The exact mechanism for this is not proven, but it is widely believed that grafts stripped of tissue are both more easily desiccated and traumatized during extraction and placement. Skeletonization is largely a consequence of a too shallow punch insertion. If at any point during an FUE surgery grafts are seen to be skeletonized, the punch depth should be set deeper until the skeletonization is minimized (Fig. 57.2a–c). There is a delicate balance in judging how deep to go because there is a point at which, particularly with sharp punches, deeper punch penetration will increase follicle transections. Blunt and newer “hybrid” punches typically allow deeper penetration without increasing transections and therefore minimize skeletonization, creating grafts more similar to FUT grafts (Fig. 57.2d). In 2018, Josephitis and Shapiro presented a side-by-side study on the same patient comparing survival of FUE versus FUT grafts. The FUE grafts in this case were obtained with the newer hybrid punch technology, and therefore had more perifollicular tissue surroundings their base. They looked similar to the FUT grafts. The survival was basically the same for FUE and FUT, using cross-section trichometry (CST; HairCheck) and hair counts as study parameters.³

Fig. 57.1 Skeletonized graft.

Fig. 57.2 (a) Sharp punch at 3.0 mm. (b) Sharp punch at 3.25 mm. (c) Sharp punch at 4.0 mm. (d) Hybrid punch at 4.5 mm.

57.2.2 Minimizing Follicle Splay

Follicular splay is the term used to describe a follicle (or all follicles within a graft) that diverges outward and away from adjacent follicles (Fig. 57.3a).⁶^,⁷^,⁸ Splay typically occurs in the proximal portion (lower one-third) of the follicular unit and can vary in degree. Dr. True has recently introduced the concept of structural splay and iatrogenic splay. Structural splay exists anatomically in the tissue and varies both among patients and within the same patient (Fig. 57.3b). Iatrogenic splay is splay produced when the FUE punch incision depth has not been adequate to overcome the tissue tethering forces during extraction. FUE techniques in which the punch is inserted superficially may often produce extreme splay of the bulb portion of the follicles as a consequence of stripping way the perifollicular tissue during the extraction phase of excision (Fig. 57.3c). Splayed grafts are very difficult to place with forceps and are more amenable to implanter placement. Graft quality problems such as skeletonization typically accompany iatrogenic splay. Dull punches and newer hybrid punches minimize splay because they allow the punch to go deeper with less risk of transection.

Fig. 57.3 (a) Splay showing follicles directed away from each other in the lower third. (b) Example of structural splay and variable splay in the same person. (c) Iatrogenic splay from stripped tissue.

57.3 Avoiding Graft Damage During Placement

57.3.1 Trauma During Graft Implantation

Graft trauma and damage can occur during the placing process. FUE grafts are particularly prone to trauma due to skeletonized grafts and increased splay. Some of the more common types of trauma that occurs during placing are the following:

•Repetitive placement trauma (RPT)1 is a term coined by Dr. Wolf. (Dr. Ron Shapiro also called this phenomenon “multiple failed attempts” in the 2004 edition of this textbook). When grafts are repeatedly handled during failed implantation attempts, the risk of graft damage and poor yield is increased.

•Crush injury, caused by squeezing the bulb too forcefully with forceps, is another cause of graft injury.

•Bent grafts (curved grafts, J-hook rafts) are a recently described entity that seems to be associated with decreased yield (and perhaps folliculitis or kinky growth). This is felt to be caused by one leg of a graft getting caught on the edge of an incision, or forceful jamming of a graft into an incision during placing (Fig. 57.4).