WHAT ARE SMAS PLICATION AND LATERAL SMAS-ECTOMY FACELIFT TECHNIQUES?
The mid-70s saw an explosion in our understanding of facial rejuvenation principles and anatomy. For the first time it was recognised that a layer in between the skin subcutaneous fat superficially, and bone and glandular structures in the deeper layer contributed a great deal to the appearance of the face. Dr Skoog, a talented and gifted surgeon postulated this without establishing the anatomical basis. It was Mitz and Peyronie who described the anatomical layer of Superficial Musculo-Aponeurotic System (SMAS) in 1976. An explosion of surgical techniques using SMAS as their foundation for surgical manipulation followed.
The simplest SMAS -based surgery involves widespread skin undermining from in front of the ear, to close to the lips and across the cheek (Fig 1). Skin undermining often extends into the neck as the procedures often need to be combined for a harmonious and good outcome. At this point the redundancy in the SMAS is marked out and using permanent or absorbable sutures, it is placated. In essence this lifts the lower face and the neck but is unable to address the mid-cheek region. The skin excess is then excised and the skin is closed in layers. The advantage of this operation is that it is very safe in regards to any possible threats to the facial nerve. The facial nerve traverses in the sub-SMAS plane. Rarely in imbrication of the SMAS, the nerve may be caught which may result in temporary or permanent facial nerve branch palsy (Fig 1).
Figure 1 (Extent of Facelift skin flap undermining in SMAS plication and lateral SMAS-ectomy)
The disadvantage of this surgical technique lies in its inability to address the mid-cheek region also offer a nuanced SMAS-based rejuvenation. The widespread undermining of the facelift surgery skin flaps leaves them prone to small areas of necrosis at the most distal part near or behind the ear. Furthermore, prolonged post-operative swelling remains a concern.
This operation is best performed under general anaesthetic and in the operating theatre settings. Any external sutures may be removed any time after 3rd to 5th post-operative days. The results are reliable if not dazzling.
Lateral SMAS-ectomy is a technique which involves excision of the redundant lateral SMAS. The principles of surgery remain the same. After initial skin incision widespread undermining towards the nose and lips, often extending into the neck is performed prior to assessing the redundancy in the SMAS. With excision of this redundancy in the SMAS or on some rare occasions it’s transpositions to other parts of the various tightening of the SMAS is achieved. Excision often allows for a more nuanced and sculpted facelift surgery outcome in comparison to SMAS plication. The risk of facial nerve damage is slightly higher than plication owing to the incision made in the SMAS (Fig 2).
Figure 2 (SMAS Plication or Imbrication Technique).
The surgery effectively has the same cost benefit profile as SMAS plication surgery. The mid cheek region remains out of the scope of this technique. The widespread skin undermining contributes to longer post-operative swelling as well as increased risk of skin flap loss. In the next blogs we will discuss extended as well as the high SMAS facelift surgeries.
Figure 3 (Lateral SMAS-ectomy Technique).
All illustrations are reproduced with permission Farhadieh RD, Bulstrode N, Cugno S: Plastic and Reconstructive Surgery: Approaches and Techniques, Wiley & Blackwell, London, UK, 2015.