Introduction

The facial aging process results from a combination of skeletal and non-skeletal soft-tissue changes that lead to specific alterations of the superficial and deep fat framework and skin layers.

As the breakdown of collagen and elastic fibers takes place, dermatochalasis of facial and neck soft tissues accounts for the distinctive signs of facial aging.

The introduction of sub-dermal suspension with threads has gradually spread among many practitioners and attracted significant interest, given that it allows to lift sagging tissues by means of a minimally invasive, closed procedure.

It is generally stated that the placement of subcutaneous threads generates a non-specific local immune as a dense connective tissue capsule with neovascularization around the implanted material that lasts several months after the procedure and involves various cell types, which plays an important buttress role in the ability of barbed suspension threads to lift facial tissues and maintain their elevated position in the long term and ensures that the lifted tissues remain in place even after the thread has degraded.

More precisely, the formation of new collagen fibers and elastic fibers results in increased collagen and elastin volume. In addition, cells produce more hyaluronic acid in response to the threads with concomitant increase in water retention. Collectively, this process results in a visibly youthful skin.

Recently, PLLA-PCA threads embedded with 1% of hyaluronic acid have been presented and animal studies already showed their unique characteristics compared to PLLA-PCA threads: an inflammation-free HA-enriched thread encapsulation, a faster elastin increase after thread insertion, and a stronger elastin presence around the implanted HA-enriched thread providing for a better quality of the surrounding dermal tissue have been demonstrated.

The authors present a pilot study based on quantitative evaluation of the aesthetic improvement of micro-wrinkles and skin texture in a split-face patient group which received implantation of HA-PLLA-PCA threads in the right and PLLA-PCA threads in the left cheek.

Materials and Methods

6 patients were enrolled in this study and treated with poly-L-lactic poly-caprolactone PLLA-PCA and hyaluronic acid HA-PLLA-PCA suspension threads to correct mild to moderate ptosis of the flabby tissues of the midface.

Local anesthesia of the skin has been performed with a solution of lidocaine 2% with epinephrine 1:100000 and, after a 15-minute waiting time for proper vasoconstriction of the superficial vessels of the face, threads were loaded in a 19 cm blunt cannula and inserted from the zygomatic arch and the pre-tragus point, to the nasolabial fold and marionette line.

HA-PLLA-PCA threads were implanted in the right and and PLLA-PCA threads in the left cheek, in order to later assess skin quality improvement and compare both sides.

The assessment was focused on a) skin micro-wrinkles; and b) skin texture (compactness and homogeneity) prior to, 30 and 90 days after threads insertion.

Patient photographs were taken using a 3D imaging system and a skin analysis software before (t0), 30 (t1) and 90 (t2) days after threads implantation.

Results

Five out of the six patients completed the study with one drop-off during the follow-up period, that was 84 days.

Three months after the insertion, HA-PLLA-PCA threads show a better clinical outcome in skin micro-wrinkles, while skin texture appears to show the same outcome as PLLA-PCA threads. 

No adverse events were reported during thread insertion or later, except for a slight aching sensation at the insertion points.

Patient discomfort was referred to be mild, mainly related to thread perception and presented with spontaneous resolution in all treated cases.

Discussion

This pilot study has been designed and carried out pushed by the common assumption that cosmetic procedures result is very subjective, yet there needs to be a method for determining the true outcome of treatments besides the mere judgement of patients and clinicians.

Digital photography and its related skin analysis software have been chosen as the method to overcome this and therefore standardized photos of the results of this study are presented, along with analytic data evaluation.

HA-PLLA-PCA threads present with an inverse peak of clinical action recorder thirty days after implantation (t1) for both investigated parameters, before reaching final improvement at t3, that points out the inverse correlation between dynamics of connective tissue around HA-threads and clinical findings: the more inflamed tissue around normal PLLA-PCA threads once inserted, lead to a more swollen and tightened skin, as recorded in the first period (t0-t1), that mimics less micro-rhytids and a better texture.

The delayed collagen synthesis, HA hydration and its anti-inflammatory properties provide for a more physiological tissue condition around the implanted thread, presenting therefore with a less relevant clinical improvement (t1), eventually ending up with the great effect on micro-wrinkles (t2).

This is indirectly confirmed by the elastin synthesis curve, that without the inverse peak, directly correlates with the final good outcome of the clinical data, pointing out that skin with implanted HA enriched threads presents with unaltered physiological features in the first post-treatment period and later improve, overcoming the normal thread outcome in micro-rugosity.

The presented results confirm the previously published histological findings, highlighting the innovative aspect and the clinically positive outcome of this new HA-PLLA-PCA thread: a less inflamed post-insertion period and a unique tool in order to obtain simultaneous lifting effect and skin rejuvenation for patient with mild to moderate ptosis of the facial tissues.

These results showed that with threads it is now possible to achieve a combined skin rejuvenating effect coupled with tissue repositioning.

To the best of our knowledge this is the first objective, standardized photographic analysis of facial skin rejuvenation obtained by means of thread insertion, carried out to overcome subjectivity of cosmetic procedures assessment in evaluating immediate and three-months post-implantation results.

Further studies on larger patient groups are indeed needed to confirm the preliminary results shown in the present study.