The Question – Why use Polydioxanone (PDO) threads for a minimally invasive lifting treatment?

The trend of seeking less invasive cosmetic treatments is growing rapidly among patients; they desire a solution for correcting sagging and ageing skin with minimal downtime and low risks.

Various cosmetic interventions have been used for non-surgical facial and neck rejuvenation.  The use of sutures for “suspension” of the face is certainly not a new concept, however it has gained prominence after the advent of the “lunchtime threadlift treatment”

The need for PDO Threadlift Treatment:

The dermal layer that acts as a scaffold for the facial skin and fat weakens as a result of the ageing process.   This can be attributed to the thinning of connective tissues and the collapse of elastin fibres ¹.   Amongst other visual signs of ageing, the jaw line becomes “loose” and begins to sag, the forehead develops horizontal lines and vertical glabellar lines and the mid-face as a whole displays a downturned appearance.   In addition, eyelid skin becomes increasingly flabby and protrudes in relation to the lower eyelids.²

Until now, the surgical facelift; a long and complicated procedure and with extensive recovery time³ has been the traditional treatment for improving the signs of facial ageing.   The recent innovation of barbed PDO sutures however offers a good minimally invasive alternative without the fear of “going under the knife”.

PDO threads are a good option for a “facelift” during the earlier stages of ageing, acting  as a preventative therapy for cheek and brow ptosis⁴ as well as helping stop the sagging of middle and lower face.

The action mechanism of PDO threads:

PDO threads threads work in two ways, firstly physical notching on the thread’s surface can create an instant mechanical lifting action.

Secondly, their presence triggers the body’s own physiological responses to produce collagen. Once the threads are inserted under the skin, they induce a local inflammatory response as the body’s natural defence mechanisms kick in in response to a foreign object.   As the threads naturally resorbed into biological fluids via dissolution, they stimulate the production of procollagen molecules as well as inducing a reactive fibrosis surrounding them, which maintains the lifting outcomes beyond their resorption.

The purpose behind insertion of PDO threads under the skin:

Collagen is produced by fibroblasts.  A mature and active fibroblast has the ability to produce around 3.5 million procollagen macromolecules a day.   This collagen forms up to 90% of the skin and is organised into large fibre bundles thus creating a 3D natural structure ⁶.  As we age the process of collagenesis dramatically slows down and components  of the extra cellular matrix e.g. elastin, glycosaminoglycans and proteoglycans are reduced.

PDO threads stimulate the skin’s natural repair processes and activate neocollagenesis as well as promoting targeted lipolyis of fatty deposits⁷

The aim of PDO thread insertion is to firstly create local microtrauma, which is followed by traumatic inflammation and its associated increase in blood supply.  By day 3 fibroblasts begin to produce procollagen protein filaments which go on to form fibres of immature collagen and the start of new connective tissue.   The next stage is collagen maturation whereby collagen fibresform bundles and cross-linking occurs over several months. The result is synthesis of bands of fibrous connective tissue that act as a strengthening scaffold helping prevent facial ptosis.

Through the use of PDO threads, it is possible to create a strong intradermal as well as subdermal grid that induces biostimulation, tissue support, progressive retraction of the skin as well as partial reshaping of tissues.   PDO therapy resulting in regeneration of connective tissue and an increase in oxygenation to the tissue.  By activating reparative and regenerative processes within the papillary dermis the PDO thread insertion process indirectly results in functional and aesthetic improvements.

Polydioxanone as a biomaterial is quite revolutionary, possessing antimicrobial and biostimulating properties in addition to being resorbable.  The degradation of the threads is prompt and starts within 15 days of insertion and takes approximately 180-200 days to complete.  Hydrolysis of the PDO polymer occurs breaking the threads down into carbon dioxide and water.

Types of PDO Micro-Threads:

There are five types of PDO threads⁸ that can be used for a PDO facelift treatment:

1. PDO Mono – these threads are 6/0-8/0 and are inserted with a 26-31G needle using the “Quilting Inn” technique into the medium to deep dermis of the skin.  They promote remodelling of he tissues.  Length varies from 12-60mm.
2. PD Screw – These 5/0-8/0 micro threads have a spiral shape and are inserted with a 26-31G needle. They are placed into the superficial or sub dermis and/or the deep dermis.  They induce biostimulation and retraction lines along the vectors of traction.  The usual length is 25-60mm.
3. PDO Embossed Thread – this is a thread with microgrooves that allow re-growth of tissues into the grooves of the thread. They are positioned at the mid to deep levels of the  subdermal layer.  The length is normally 25-60mm.
4. PDO Cogs – these are barbed threads that can be mono, bi as well as three-directional with a length of 50-90mm. This thread is mainly aims to create suspension of the tissues by stimulating collagen production by fibroblasts along the axis of the thread.
5. PDO Mini Cannulas – The use of blunt cannulas for inserting barbed or straight threads minimises the risk of haematomas in delicate areas such as around the eyes and the temporal region. They are also ones suitable for the nose tip and neck.

Techniques of Inserting PDO threads:

It is a well established fact that correctly inserted PDO threads into the tissue results in lifting of the skin and these results are maintained through collagen formation⁹.   In most cases monofilament, spiral or cog lift threads are enough to achieve a satisfactory outcome.

In the case of lifting the mid face and mandibular jowl, different techniques need to be used. There are 5-, 10- and 11- point, 10 point and even an  11-point facelift procedures available but they are not appropriate for all cases.   The aesthetic practitioner should do case-by-case evaluation and determine the actual number of elevation points required to produce the desired lifting effect.  If there is facial asymmetry, the number and position of these threads may differ on each side of the face and neck.

Depth of PDO Insertion:

The correct depth for inserting barbed PDO threads is in the Superficial Muscular Aponeurotic System (SMAS).   If they are inserted too superficially within the dermal plane then they may be seen or felt and would fail to provide the required lifting and collagen production stimulation.

Placed too deep and they would pose a greater risk of damage to arteries, veins, the facial nerve and causing other structural damage.

Therefore it is crucial for the aesthetic practitioner performing any treatment with PDO threads to have a detailed and in depth knowledge of head and neck anatomy.  Particularly they should note the importance of Manson’s point which provides 100% identification of the facial artery within 3mm in living human subjects¹¹

Side effects

The common side effects of the treatment are swelling, bruising which usually resolves in a few days and slight bleeding.   Infection is always a possibility but its likelihood can be minimised by aseptic conditions and correct technique. The phenomenon of post -operative folds have been seen in a few cases¹²

Migration of threads can occur due to poor insertion and is more common if uni or bi-directional threads are used.  The latest multidirectional 3D cog threads do not migrate.

There may be visible protrusion of small mono or spiral threads from the skin and this can be resolved by cutting the thread back.  This can be seen sometimes up to a few days after insertion.

Serious complications include damage to blood vessels and  facial nerve damage, resulting in facial paralysis.

The Duration of Results

Due to PDO threads being a relatively recent innovation in medical aesthetics there is a lack of long term clinical studies in relation to duration of treatment outcomes.  However the results of short term research studies have shown that results obtained from  PDO threads were maintained for nearly 6 months on the whole with a little loss of elasticity from facial tissues¹³ The average patient has been found to be satisfied for 12 months and in some cases patients are happy with the outcome for up to 18 months¹⁴.

Conclusion:

PDO threadlift treatment offers a safe and effective way of achieving a lifting effect of the face and body, however they require correct placement in the the appropriate tissue plane for achieving optimal results, which continue to improve after absorption of the threads.  The common side effects (swelling, bruising etc) usually resolve after a few days, however very severe complications can result from incorrect insertion.  The duration of results varies from 6 to 18 months.

References:

1) Helfrich YR, Sachs DL, Voorhees JJ. Overview of skin aging and photoaging. Dermatol Nurs. 2008;20:177–183

2) Nkengne A, Bertin C. Aging and facial changes–documenting clinical signs, part 1: clinical changes of the aging face. Skinmed. 2012;10:284–289.

3) Chaffoo RA. Complications in facelift surgery: avoidance and management. Facial Plast Surg Clin North Am. 2013;21:551–558. doi: 10.1016/j.fsc.2013.07.007.

4) Paul MD. Barbed sutures for aesthetic facial plastic surgery: Indications and techniques. Clin Plast Surg. 2008;35:451–61

5) Javier de Benito et al. Aesthetic and Plastic surgery. April 2011, volume 2. Facial rejuvenation and improvement of malar projection using sutures with absorbable cones: surgical technique and case series.

6)  Stephens P., Genever P. Non-epithelial oral mucosal progenitor cell populations. Oral Dis. 2007; 13, 1: 1–10.Chang H., Chi-J T., Dudoit S. et Al. Divercity, topographic differentiation, and positional memory in human fibroblasts. Proc Natl Acad Sci. USA. 2002; 99, 20: 12877–12882

7) Wu WT. Barbed sutures in facial rejuvenation. Aesthet Surg J. 2004;24:582–7. [PubMed]

• DeLorenzi C. Barbed sutures: Rationale and technique. Aesthet Surg J. 2006;26:223–9.
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• Sulamanidze M, Shiffman, Paikidze T, Sulamanidze G. Facial lifting with APTOS Threads. International Journal of Cosmetic Surgery and Aesthetic Dermatology. 2001;3:275–281.
• Sulamanidze M, Sulamanidze G. Lifting of soft tissues: old philosophy, new approach – a method of internal stitching

8) Langevin H et al, ‘Subcutaneous Tissiue Fibroblast Cytoskeletal Remodeling Induced by Acupuncture: Evidence for a Mechanotransduction-Based Mechanism,’ Journal of Cell Physiology (2006) pp.767-764.

• 9) Mitz V, Peyronie M, ‘The superficial musculo-aponeurotic system (SMAS) in the parotid and cheek area,’ Plastic Reconstructive Surgery, (1996) <http://www.ncbi.nlm.nih.gov/pubmed/935283>
• Jacono, A, Narayan, S, ‘Extended SMAS Facelift’ (2014) <Andreq Jacono, Deepak Marayan Extended SMAS Facelif >
• Padin, VL, ‘Experience in the Use of Barbed Threads and Non- Barbed Serdev Sutures in Face and Body Lift – Comparison and Combination,’ Miniinvasive Face and Body Lifts – Closed Suture Lifts or Barbed Thread Lifts (2013), http://www.intechopen.com/ books/miniinvasive-face-and-body-lifts-closed-suture-lifts-or-barbed-thread-lifts/experience-in-the-use-of-barbed-threads-and-non-barbed-serdev-sutures-in-face-and-body-lift-comparis

10) Calva D, Chopra KK, Sosin M, De La Cruz C, Bojovic B, Rodriguez ED, Manson PN, Christy MR, ‘Manson’s Point’ A facial landmark to identify the facial artery. Journ Plast Reconstr Aesthet Surg 68(9) (2015), pp.1221.

• https://aestheticsjournal.com/feature/pdo-threadlifting

12) PDS (Polydioxanone suture) A new Synthetic Absorbable Suture in Cataract Surgery. A Preliminary study. Bartholomew R.S. Dept of Opthalmology,University of Edinburgh,Scotland,UK Opthalmalogica 1981;183:8181-85 DOI :10.1159/000309144

13) Pawar, SS, Meyers, AD, et al, ‘Complications of facelift surgery,’ (2014) <http://emedicine.medscape.com/article/843613-overview>

14) Llorca, V, MD & Soyano, S, ‘Lifting effect with polydioxannone absorbable threads without anchors on face and neck,’ Unidad Antiaging Hospital de Levante Benidorm (2006).