Since absorbable threads were first used for facelifts in the late 1990s [1], the use of threads was subsequently extended to rhinoplasty and became highly popular with the trend of favoring minimally invasive procedures in facial aesthetic surgery [2]. Synthetic, absorbable, monofilament polydioxanone (PDO) sutures, which are slowly absorbed by hydrolysis over several months, are most commonly used in thread rhinoplasty [3]. PDO sutures have a barbed structure, such that multiple barbs are caught by tissue fibers and thus can firmly attach [4]. The threads can be inserted in the nasal dorsum, nasal tip, or both, with several threads inserted into each structure. For improved aesthetic outcomes, thread rhinoplasty is commonly combined with filler injection or fat grafting to supplement the deficient volume [4-6]. Nonsurgical rhinoplasty using barbed threads is emphasized as a safe and straightforward procedure free from anesthesia, the post-surgical recovery process, and surgery-related complications. Therefore, thread rhinoplasty is currently widely performed in daily practice.

Several studies have reported the techniques and surgical outcomes of nonsurgical rhinoplasty using barbed threads [4,5,7]. They noted that thread rhinoplasty is an effective alternative to conventional rhinoplasty, with high patient satisfaction and no or few minor complications. While the benefits of thread rhinoplasty have been emphasized, its complications tend to be overlooked [8]. Only a few studies have reported complications of thread rhinoplasty, and they were limited to cases of inflammation or infection [9,10]. Some patients in a previous report experienced severe infection, including abscess and skin necrosis with an open wound [9]. However, other complications, such as thread extrusion, palpable threads, or aesthetic dissatisfaction, have not been reported. Surgical techniques and considerations for revising those cases have never been reported, despite their clinical importance. As thread rhinoplasty is becoming more popular, the incidence of these complications is also increasing, and the demand for revision surgery will also increase. In this study, we reviewed a case series of revision rhinoplasty performed due to complications of thread rhinoplasty, and reported the presentation patterns of the complications, the surgical management, and the outcomes.

This study is a retrospective review of patients who underwent revision rhinoplasty for the complications of thread rhinoplasty, performed by Dr. Hong Ryul Jin at Dr. Jin’s Premium Nose Clinic in Seoul, Republic of Korea. The study was approved by the Institutional Review Board of the National Medical Center (IRB No. 2021-0292-001). The informed consent was waived due to the retrospective nature of the study. However, written informed consent for the use of pre- and postoperative facial photographs was obtained from all patients before surgery with a full explanation.

Seven patients who underwent revision rhinoplasty due to complications and/or aesthetic dissatisfaction after thread rhinoplasty from January 2018 to May 2021 were analyzed (Table 1). They comprised six females and one male, and their mean age was 26±6 years (range, 18–36 years). The patients had a history of thread rhinoplasty at various clinics. We reviewed the medical record to obtain the following information: chief complaint, the reason for seeking revision rhinoplasty, time of thread insertion, and accompanied procedures with thread insertion. Status of the thread (shape and degree of absorption), location, number of inserted threads, and the degree of adhesion with the surrounding tissues were analyzed with operative photos and surgical records. Detailed surgical techniques, the type of autologous tissue used for revision, and any significant findings during the surgery were also recorded and reviewed. The surgical outcome was measured as patient satisfaction with categorical variables (very satisfied, satisfied, and dissatisfied). For statistical analysis, a descriptive analysis was performed using IBM SPSS ver. 27.0 software (IBM Corp., Armonk, NY, USA).

A notable aspect of our study was that the threads were not resorbed even years after insertion. In most patients, the threads maintained their original shape and volume with intact cogs. It is known that the PDO threads used in thread rhinoplasty are absorbed into the tissue gradually by hydrolysis [3]. An animal study using pigs revealed that the inserted threads became fragmented by 24 weeks and completely dissolved by 48 weeks [11]. In that experimental study, USP 4-0 non-barbed PDO threads were inserted separately at 1-cm intervals. The histological changes of the surrounding tissues after thread insertion included collagen production, the development of new fibrous connective tissue that merged with the existing tissue, fat reduction, tissue contracture, and improved vascular supply [11]. A rat model study using four different PDO thread types (single-stranded, 4-stranded, 12-stranded, and barbed cog threads) also demonstrated a similar tissue response and collagen formation, with 24 weeks taken for degradation [12]. The factors contributing to these tissue changes have not yet been elucidated.

Possible explanations for the intact threads even years after surgery in our cases are as follows. First, although the threads were made of absorbable components, thick threads rarely dissolve in the nose tissue, where the soft tissue layer is rather thin. Second, when a filler is used concurrently with PDO threads, hyaluronic acid has been reported to block the chemical reaction between PDO and water, thereby prolonging the life of the PDO threads [6]. In our series, the combined use of fillers was unclear due to the lack of previous medical records. Third, non-absorbable threads or a combination of absorbable and non-absorbable threads might have been used in the previous surgery. One study reported a complication with polypropylene non-absorbable threads [10]. In Korea, a non-absorbable polypropylene product named Everko (Dongbang Medical, Seongnam, Korea) was once commercially available for thread rhinoplasty.

Thread exposure at the tip is mostly caused by an incorrect insertion technique. To prevent thread extrusion at the tip, the threads must be inserted deep in the tissue between the medial crura and should not reach higher than the intermediate crus, retaining a sufficient cushion layer on the top of the upper end [6]. If the thread is not inserted deep enough or a longer thread is inserted, the chance for extrusion or a visible thread at the tip skin increases. Because the tip is a mobile portion with relatively poor blood circulation, an improper insertion technique inevitably results in pain, thread exposure, or infection [9]. The removal of tip threads often reduces tip projection. When multiple threads are removed by deep intercrural dissection, the tip support is lost due to weak medial crura with a slight loss of intercrural tissue. Tip support must be restored either with a columellar strut or septal extension graft for an improved aesthetic result. All patients in our series needed tip support restoration using a combination of a columellar strut, septal extension graft, and onlay graft.

In our series, thread removal on the dorsum was inevitably accompanied by a slight tissue loss and dorsal irregularity, especially in patients with think skin. The patterns of thread cogs grasp the tissue firmly and prevent extrusion. This advantage may act as a disadvantage when removing the threads. Since tissue adhered to the cog prevents slippage of the thread, removal requires careful tissue dissection. This may cause a slight tissue loss on the dorsum and dorsal skin irregularities. Because most patients wanted a raised bridge or at least a regular dorsum after thread removal, dorsal camouflage or augmentation was necessary to achieve an improved dorsal shape. For natural-looking camouflage, soft tissue such as the fascia or perichondrium was helpful [13]. We used the temporalis fascia in two patients, the postauricular soft tissue in one, and rib perichondrium in another for dorsal skin camouflage.

Although our series did not have such cases, severe infections, including abscess and skin necrosis with an open wound, have also been reported [9]. Suggested factors contributing to infection are a previously inserted allograft, the insertion of too many threads, absence of aseptic preparation, anatomical features, and the high absorbability of PDO threads that increases the inflammation around the threads [9]. Absorbable PDO has hydrophilic properties and therefore elicits a more severe tissue inflammatory reaction than non-absorbable threads [10]. All previously reported infections occurred when PDO threads were used [9,10].

It is not clear how many threads should ideally be inserted. In previous studies describing the surgical technique of thread rhinoplasty, the authors described different numbers of threads on the dorsum and the columella [4-6]. The number of inserted threads can be influenced by skin thickness, types of threads, combined fat grafting, or the use of hyaluronic acid filler injection. Most reports described two to five threads on the dorsum and two to five threads on the columella, resulting in a total of four to 10 threads [4-6]. Two additional threads were inserted into each alar rim to reduce the nostril show as necessary [4]. Our case series showed an average of 14.67±3.83 threads (range, 10–21), which is much more than reported in previous studies describing the surgical technique (range, 4–10) [4-6].

Thread rhinoplasty can be an effective way to increase mild tip ptosis, or when a slight volume increase of the dorsum is needed in patients with thick skin. However, surgical rhinoplasty using grafts is preferable when a considerable change of the tip projection or dorsal height is required. In our case series, many threads were overly inserted into the tip and the dorsum to achieve a considerable change, and these overdone procedures resulted in complications. Although thread rhinoplasty is a simple procedure that can be performed in an outpatient clinic with minimal anesthesia, the surgeon should be aware of the proper techniques, limitations, and possible complications of thread rhinoplasty.

This study has limitations, as it is a small case series with limited information on the previous procedures. Further studies with a larger case series and more information regarding the previous thread insertion are needed. Nevertheless, this is the first case series reporting detailed surgical techniques and considerations for revision rhinoplasty to correct the complications of thread rhinoplasty, and the findings are expected to be helpful for both patients and surgeons to recognize the risks of thread rhinoplasty and approach the surgical management of such complications.

In this case series of complications of thread rhinoplasty, we found that the threads maintained their original shape without undergoing resorption even years after insertion. Thread removal required careful dissection due to adherent tissue around the cog, inevitably causing a slight loss of the surrounding soft tissue with structural weakening. Reinforcement of the tip support and camouflage of possible dorsal irregularity are key steps for an improved aesthetic outcome.