Recently, non-surgical rhinoplasty using either hyaluronic acid (HA) filler or polydioxanone (PDO) thread has been gaining popularity. Particularly, either thread or thread combined with HA filler has been preferentially used for nasal tip projection [1]. However, thread extrusion as a possible complication frequently occurs [2]. Thread extrusion usually happens around the nasal tip which is an entry site for thread insertion.

In terms of the thread insertion method, although the technique has improved, which is currently most commonly used [3], we analyzed the cause of this result. Due to the high pressure applied to the vertically inserted thread to lift the tip of the nose, the soft tissue of the tip of the nose could not overcome this pressure, resulting in the thread being pushed out of the nose.

The authors thought that changing the insertion position of the thread could prevent this complication, and as a result, this modified method was introduced because it showed good results in preventing the side effect.

Skin, including the nasal cavity, was disinfected with 10% iodopovidone. A solution of 1:100,000 adrenaline in 2% lidocaine was injected into the entry site, located 0.5 cm above the supratip break point, infiltrated into the nasolabial angle deep to the nasal spine, and placed just above the perichondrium of the upper lateral cartilage and the subperiosteal layer of the nasal bone along the midline of the nasal bridge using a 30G sharp needle.

A blunt cannula (6.5 cm length) pre-loaded with a thread (Elasty V BARD^TM PDO, 8.5 cm length; Dongbang Medical Co. Ltd., Seongnam, Korea) was manually bent around 30° at a distance of 1.5 cm from the distal end of the cannular as shown in Fig. 1.

Figure 1. The insertion technique by turning of the bent cannular. (A) A schematic view of an Elasty V BARD^TM polydioxanone (PDO) thread (8.5-cm long) inserted into the blunt cannular (6.5-cm long). (B) The bent cannular as a schematic view of A was placed parallel to the perichondrium of the upper lateral cartilage, moved down to the middle of the nasal tip (1, as a black line). At this moment, it was turned 180° (2, as a white line), and placed in the middle of the columella, until it finally reached each side of the nasal spine of the maxilla (3, as a red line). The orange arrow shows the entry site, and the red arrow shows the moving direction of the cannular.

The entry site was opened using an 18G needle. The cannular was inserted at the entry site and moved forward just above the upper lateral cartilage until it reached the middle of the nasal tip. The cannular was rotated 180° and pushed vertically to reach either side of the nasal spine along the middle of the columella as shown in Fig. 1B. Four threads were then inserted.

In the case of HA filler injection for dorsal augmentation, the lidocaine solution was infiltrated into the subperiosteal and supraperichondral layer 10 minutes before the filler injection. An average of 90% volume of the filler (Elasty Grand plus Hyaluronic Acid Filler; Dongbang Medical Co. Ltd.) was subperiosteally and supraperichondrally injected from the nasion to the supratip breakpoint and 10% volume was placed into the deep and superficial fat layer along the midline of the nasal bridge using a 23G sharp needle as shown in Fig. 2G.

Figure 2. A case of preventing polydioxanone (PDO) thread extrusion from the nasal tip combined with hyaluronic acid (HA) filler for dorsal augmentation. Four threads for tip projection and 1.0 ml of HA filler for dorsal augmentation were used. This was a 24-year-old woman who underwent thread insertion for the nasal tip and HA filler injection for the nasal bridge. (A, D) Before the procedure; (B, E) 1 month after the procedure; (C, F) 2 years after the procedure; and (G) schematic lateral view of the entry site (orange-colored arrow) for the PDO thread insertion and placement of HA filler.

In the case of augmentation by the combination of thread and HA filler, the thread was inserted through the infratip break point as shown in Fig. 3E and HA filler was infiltrated as mentioned above.

Figure 3. A case of prevention of polydioxanone (PDO) thread extrusion from the nasal tip combined with hyaluronic acid (HA) filler and PDO thread for dorsal augmentation. Four threads for tip projection and eight threads and 1.3 ml of filler for dorsal augmentation were placed. This was a 37-year-old man who underwent thread insertion for the nasal tip and HA filler injection for the nasal bridge. (A, C) Before the procedure; (B, D) 4 months after the procedure; and (E) schematic lateral view of two entry sites and placement of the threads and HA. 1, entry site for tip projection; 2, entry site for dorsal augmentation for the thread.

Considering the dynamic structure of the nose, the procedure for the nasal tip projection was performed first, followed by other procedures for the dorsal augmentation.

Thread extrusion was prevented by changing the entry site for nasal tip projection. A natural contour of nasal dorsum, and an obvious tip projection with an increased nasolabial angle were also observed (Fig. 2, 3).

In line with the increased preference for non-surgical cosmetic procedures, the popularity of rhinoplasty using threads combined with botulinum toxin and filler has increased [1,3-5]. Despite the occurrence of complications including infection, thread extrusion, chronic inflammation, and dimpling [2,5,6], there has been no report on treatment methods that can improve those complications, which are mainly caused by thread extrusion. As shown in Fig. 4, thread extrusion usually occurs within 2 weeks of the procedure. Eventually, it might lead to skin perforation, infection, and a permanent depressed scar if not removed immediately.

Figure 4. A case of polydioxanone (PDO) thread extrusion from the nasal tip. This was a 65-year-old woman who underwent thread insertion for the nasal tip and hyaluronic acid (HA) filler injection for the nasal bridge. Four threads for tip projection and 0.8 ml of HA filler for dorsal augmentation were used. (A, D) Before the procedure; (B, E) 2 weeks after the procedure; (C, F) 1 month after the procedure; and (G) a schematic lateral view of the entry site (orange-colored arrow) for the PDO thread insertion and placement of HA filler.

However, as shown in Fig. 1, the authors developed a technique to prevent thread extrusion by changing the entry site from the tip to the supratip break region and modified the blunt cannular by manual bending. The threads were placed in the form of an inverted L-shape which leads to projection and rotation of the nasal tip as shown in Fig. 2 and 3. The results indicate that this technique not only prevents thread extrusion, but also results in a natural contour with an increased nasolabial angle and significant dorsal augmentation. Additionally, the proximal part of the inverted L-shaped thread was placed beneath either the HA filler (Fig. 2) or a combination of HA filler and thread (Fig. 3). It is believed that the contour of the inverted L-shaped thread was well maintained.

For dorsal augmentation, the threads were inserted on the periosteal layer and beneath the deep fat layer. However, in the region of the supratip break, it was placed over the proximal end of the nasal tip thread in order to maintain the contour of the inverted L-shape. Owing to the pre-infiltrated lidocaine solution, the filler was easily infiltrated into the subperiosteal and supraperichondral layer.

Kang et al. [4] used both HA filler and PDO thread for nasal tip projection. In this study, mesh thread was used instead of cogged thread. As mesh thread has a weaker supporting force than cog thread, the HA filler was used to reinforce the mesh thread and stimulate tissue formation. Since the purpose of this study was to introduce ways of preventing thread extrusion, filler was not used for the nasal tip projection. However, for reference, the results of Kang et al. [7], who projected and rotated the tip of the nose using only fillers, remind us of the importance of volume increase due to fillers is in maintaining the shape and contour of the tip of the nose.

Using these techniques, the authors showed 2 cases with natural look augmentation where thread extrusion was prevented. Thus, it is a simple, safe and reliable technique for non-invasive rhinoplasty.

The authors have nothing to disclose.