**6. PDO threads**

Alcamo was the first to use barbed threads and is given credit for his invention in 1964 [25]. These threads were hand cut and barbs were unidirectional. MacKenzie [26] is credited with the development of the bidirectional barbed thread. In the late 1980s, Sulamanidze noted the use of modified polypropylene sutures for subcutaneous facial lifting without skin excision [27]. Aptos threads were developed and became popular for improving soft tissue pendulosity since little downtime was required. While some patients experienced good results, many major complications were reported, including breakage, rippling, facial distortion, extrusion, infection, and cheese wiring of the suture through the skin [28]. Wu [29] developed his own version of a barbed thread and noted that all effects were lost over time; patients needed to repeat the procedure in order to retain benefit. Ruff was awarded a patent for developing a barbed thread in 1994, with his first prototype a weed whacker cord [30]. FDA clearance in the USA was achieved in 2004, when a polypropylene, then later a polydioxanone device, was developed by Quill. Shortly thereafter, the contour thread was withdrawn from the market. At the time, threads had attained some notoriety due to a combination of use by poorly trained individuals and a rash of publicized complications. Threads have made a bit of a comeback, as better training and safer resorbable sutures are being introduced. Currently there are several remaining barbed sutures available in US origin. Stratafix, a permanent barbed suture by Ethicon, has been discontinued in practice due to the intense fibrotic response and patient complaints of inflammation and discomfort in the treatment region. V-lock is resorbable and seems better tolerated, especially in breast surgery. Silhouette is FDA cleared for midface lifting [30] and also claims to be biostimulatory [31]. Since 2015, several companies have applied for FDA clearance of their polydioxanone threads for the approximation of the skin. Miracu threads [32] have received FDA clearance for both the PDO thread and the cannula insertion device.

Many styles of PDO threads are available. Filler threads have no fixation and are intended to supply a small amount of volume as well as hypodermal stimulation. Bidirectional barbed threads can be placed with a needle from the center of the treatment region. An alternative is the placement of these threads from within a cannula which avoids a central puncture mark. "Spring" threads are used in areas where

**63**

**Figure 11.**

*2 years.*

**Figure 10.**

*augment the volumetric correction.*

*Combining PDO Threads with Exosomes for Microlifting DOI: http://dx.doi.org/10.5772/intechopen.91796*

dynamic motion is prominent and might be restricted with a linear model. The novel Meshfill device (**Figure 10**) is a cylinder made of 16 tiny woven PDO threads that is inserted within a cannula. Prior to cannula withdrawal, 0.2 cc of either filler or fat can be injected into the internal space. The concept of an injectable implant has a great utility. In regions where a firm or defined contour is needed—the chin, cheek, or jawline, for example—these devices can be stacked or lined up to dramatically enhance shape. In regions where a linear depression is noted—the nasolabial fold—dramatic rather than subtle correction can be obtained with a very small amount of additional filler or fat.

*Diagram of Meshfill construction. Sixteen tiny PDO threads are woven and placed on a 21 gauge cannula. These cylindrical structures can be used as filler threads by themselves or can be filled with fat or fillers to* 

*Miracu line thread. This PDO thread employs barbs and cogs in a double-coated structure that lasts up to* 

#### *Combining PDO Threads with Exosomes for Microlifting DOI: http://dx.doi.org/10.5772/intechopen.91796*

dynamic motion is prominent and might be restricted with a linear model. The novel Meshfill device (**Figure 10**) is a cylinder made of 16 tiny woven PDO threads that is inserted within a cannula. Prior to cannula withdrawal, 0.2 cc of either filler or fat can be injected into the internal space. The concept of an injectable implant has a great utility. In regions where a firm or defined contour is needed—the chin, cheek, or jawline, for example—these devices can be stacked or lined up to dramatically enhance shape. In regions where a linear depression is noted—the nasolabial fold—dramatic rather than subtle correction can be obtained with a very small amount of additional filler or fat.

#### **Figure 10.**

*Cosmetic Surgery*

**Figure 9.**

*re-epithelialization.*

**6. PDO threads**

treated with buffer alone and two times as fast as the region treated with depleted media. The response was dose related; the dose of 10 mcg/ml seemed optimal in laboratory conditions. Clinical use of topical exosomes is noted to improve healing

*Clinical effect of exosomes. (A) A 62-year-old patient 2 days following ablative erbium laser resurfacing. (B) The same patient on day 5. Usually these patients require 7–10 days of healing in order to achieve* 

Alcamo was the first to use barbed threads and is given credit for his invention in 1964 [25]. These threads were hand cut and barbs were unidirectional. MacKenzie [26] is credited with the development of the bidirectional barbed thread. In the late 1980s, Sulamanidze noted the use of modified polypropylene sutures for subcutaneous facial lifting without skin excision [27]. Aptos threads were developed and became popular for improving soft tissue pendulosity since little downtime was required. While some patients experienced good results, many major complications were reported, including breakage, rippling, facial distortion, extrusion, infection, and cheese wiring of the suture through the skin [28]. Wu [29] developed his own version of a barbed thread and noted that all effects were lost over time; patients needed to repeat the procedure in order to retain benefit. Ruff was awarded a patent for developing a barbed thread in 1994, with his first prototype a weed whacker cord [30]. FDA clearance in the USA was achieved in 2004, when a polypropylene, then later a polydioxanone device, was developed by Quill. Shortly thereafter, the contour thread was withdrawn from the market. At the time, threads had attained some notoriety due to a combination of use by poorly trained individuals and a rash of publicized complications. Threads have made a bit of a comeback, as better training and safer resorbable sutures are being introduced. Currently there are several remaining barbed sutures available in US origin. Stratafix, a permanent barbed suture by Ethicon, has been discontinued in practice due to the intense fibrotic response and patient complaints of inflammation and discomfort in the treatment region. V-lock is resorbable and seems better tolerated, especially in breast surgery. Silhouette is FDA cleared for midface lifting [30] and also claims to be biostimulatory [31]. Since 2015, several companies have applied for FDA clearance of their polydioxanone threads for the approximation of the skin. Miracu threads [32] have received FDA clearance for

in patients who undergo fractional resurfacing procedures.

both the PDO thread and the cannula insertion device.

Many styles of PDO threads are available. Filler threads have no fixation and are intended to supply a small amount of volume as well as hypodermal stimulation. Bidirectional barbed threads can be placed with a needle from the center of the treatment region. An alternative is the placement of these threads from within a cannula which avoids a central puncture mark. "Spring" threads are used in areas where

**62**

*Diagram of Meshfill construction. Sixteen tiny PDO threads are woven and placed on a 21 gauge cannula. These cylindrical structures can be used as filler threads by themselves or can be filled with fat or fillers to augment the volumetric correction.*

#### **Figure 11.** *Miracu line thread. This PDO thread employs barbs and cogs in a double-coated structure that lasts up to 2 years.*

A new addition to the portfolio is a double-coated PDO thread that combined barbs and cogs. The Miracu Line TM device is molded, not cut, so there is no weak point along the thread (**Figure 11**). The thread called "Line" lasts for 2 years. As the outer coating is resorbed, the inner thread maintains a presence and continues to offer soft tissue support. Because of the semipermanent nature of the Line thread, it is recommended that only skilled physicians use the device, with care taken to place it deep enough so that a contour defect is avoided. Manipulation of these threads should not be overdone as they are difficult to remove.
